Representations of the Schroedinger group and matrix orthogonal polynomials
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Vinet, Luc [Centre de recherches mathematiques, Universite de Montreal, CP 6128, succ. Centre-ville, Montreal, QC H3C 3J7 (Canada); Zhedanov, Alexei, E-mail: luc.vinet@umontreal.ca, E-mail: zhedanov@fti.dn.ua [Donetsk Institute for Physics and Technology, Donetsk 83114 (Ukraine)
2011-09-02
The representations of the Schroedinger group in one space dimension are explicitly constructed in the basis of the harmonic oscillator states. These representations are seen to involve matrix orthogonal polynomials in a discrete variable that have Charlier and Meixner polynomials as building blocks. The underlying Lie-theoretic framework allows for a systematic derivation of the structural formulas (recurrence relations, difference equations, Rodrigues' formula, etc) that these matrix orthogonal polynomials satisfy. (paper)
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Oeckl, Robert [Centro de Ciencias Matematicas, Universidad Nacional Autonoma de Mexico, Campus Morelia, C.P. 58190, Morelia, Michoacan (Mexico)
2012-07-15
We establish a precise isomorphism between the Schroedinger representation and the holomorphic representation in linear and affine field theory. In the linear case, this isomorphism is induced by a one-to-one correspondence between complex structures and Schroedinger vacua. In the affine case we obtain similar results, with the role of the vacuum now taken by a whole family of coherent states. In order to establish these results we exhibit a rigorous construction of the Schroedinger representation and use a suitable generalization of the Segal-Bargmann transform. Our construction is based on geometric quantization and applies to any real polarization and its pairing with any Kaehler polarization.
A life of Erwin Schroedinger. 2. ed.; Erwin Schroedinger. Eine Biographie
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Moore, Walter J.
2015-07-01
Erwin Schroedinger (1887-1961) was a pioneer of quantum physics, one of the most important scientist of the 20th century at all and a charming Austrian. He was a man with a passionate interest for men and ideas. Mostly known he became by his representation of quantum theory in the form of wave mechanics, for which he obtained the Nobel prize for physics and naturally by the famous thought experiment ''Schroedingers cat''. Walter Moore's biography is quite near to the person of Schroedinger and presents his scientific work in the context of his friendships, his interset for mysticism, and in front of the moving background of the political events in Germany and Austria.
The Schroedinger eigenvalue march
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Tannous, C; Langlois, J, E-mail: tannous@univ-brest.fr [Laboratoire de Magnetisme de Bretagne, CNRS-FRE 3117, Universite de Bretagne Occidentale, BP: 809 Brest CEDEX 29285 (France)
2011-11-15
A simple numerical method for the determination of Schroedinger equation eigenvalues is introduced. It is based on a marching process that starts from an arbitrary point, proceeds in two opposite directions simultaneously and stops after a tolerance criterion is met. The method is applied to solving several 1D potential problems including symmetric double-well (ammonia inversion problem) and Johnson asymmetric potentials, 3D hydrogen atom and Morse potential. Band structure calculation can equally be tackled by extending marching to the complex plane as illustrated with the Kronig-Penney problem.
The Schroedinger-Virasoro algebra. Mathematical structure and dynamical Schroedinger symmetries
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Unterberger, Jeremie [Henri Poincare Univ., Vandoeuvre-les-Nancy (France). Inst. Elie Cartan; Roger, Claude [Lyon I Univ., Villeurbanne (France). Dept. de Mathematiques
2012-07-01
This monograph provides the first up-to-date and self-contained presentation of a recently discovered mathematical structure the Schroedinger-Virasoro algebra. Just as Poincare invariance or conformal (Virasoro) invariance play a key role in understanding, respectively, elementary particles and two-dimensional equilibrium statistical physics, this algebra of non-relativistic conformal symmetries may be expected to apply itself naturally to the study of some models of non-equilibrium statistical physics, or more specifically in the context of recent developments related to the non-relativistic AdS/CFT correspondence. The study of the structure of this infinite-dimensional Lie algebra touches upon topics as various as statistical physics, vertex algebras, Poisson geometry, integrable systems and supergeometry as well as representation theory, the cohomology of infinite-dimensional Lie algebras, and the spectral theory of Schroedinger operators. (orig.)
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Zuniga S, A. [Instituto Politecnico Nacional, Departamento de Fisica, Escuela Superior de Fisica y Matematicas, Edificio 9, Unidad Profesional Adolfo Lopez Mateos, 07738 Mexico D.F. (Mexico)
2003-07-01
Employing canonical transformations defined in the coherent-state representation of quantum mechanics, we introduce Schroedinger-Cat- Like-States. The squeezed displaced number states with real squeezing parameter are contained in these states. (Author)
Effective Schroedinger equations on submanifolds
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Wachsmuth, Jakob
2010-02-11
In this thesis the time dependent Schroedinger equation is considered on a Riemannian manifold A with a potential that localizes a certain class of states close to a fixed submanifold C, the constraint manifold. When the potential is scaled in the directions normal to C by a small parameter epsilon, the solutions concentrate in an epsilon-neighborhood of the submanifold. An effective Schroedinger equation on the submanifold C is derived and it is shown that its solutions, suitably lifted to A, approximate the solutions of the original equation on A up to errors of order {epsilon}{sup 3} vertical stroke t vertical stroke at time t. Furthermore, it is proved that, under reasonable conditions, the eigenvalues of the corresponding Hamiltonians below a certain energy coincide upto errors of order {epsilon}{sup 3}. These results holds in the situation where tangential and normal energies are of the same order, and where exchange between normal and tangential energies occurs. In earlier results tangential energies were assumed to be small compared to normal energies, and rather restrictive assumptions were needed, to ensure that the separation of energies is maintained during the time evolution. The most important consequence of this thesis is that now constraining potentials that change their shape along the submanifold can be treated, which is the typical situation in applications like molecular dynamics and quantum waveguides.
Schroedinger's Cat is not Alone
Gato, Beatriz
2010-01-01
We introduce the `Complete Wave Function' and deduce that all living beings, not just Schroedinger's cat, are actually described by a superposition of `alive' and `dead' quantum states; otherwise they would never die. Therefore this proposal provides a quantum mechanical explanation to the world-wide observation that we all pass away. Next we consider the Measurement problem in the framework of M-theory. For this purpose, together with Schroedinger's cat we also place inside the box Rasputin's cat, which is unaffected by poisson. We analyse the system identifying its excitations (catons and catinos) and we discuss its evolution: either to a classical fight or to a quantum entanglement. We also propose the $BSV\\Psi$ scenario, which implements the Complete Wave Function as well as the Big Bang and the String Landscape in a very (super)natural way. Then we test the gravitational decoherence of the entangled system applying an experimental setting due to Galileo. We also discuss the Information Loss paradox. For ...
Erwin Schroedinger, Francis Crick and epigenetic stability
Directory of Open Access Journals (Sweden)
Ogryzko Vasily V
2008-04-01
Full Text Available Abstract Schroedinger's book 'What is Life?' is widely credited for having played a crucial role in development of molecular and cellular biology. My essay revisits the issues raised by this book from the modern perspective of epigenetics and systems biology. I contrast two classes of potential mechanisms of epigenetic stability: 'epigenetic templating' and 'systems biology' approaches, and consider them from the point of view expressed by Schroedinger. I also discuss how quantum entanglement, a nonclassical feature of quantum mechanics, can help to address the 'problem of small numbers' that led Schroedinger to promote the idea of a molecular code-script for explaining the stability of biological order.
Erwin Schroedinger, Francis Crick and epigenetic stability.
Ogryzko, Vasily V
2008-04-17
Schroedinger's book 'What is Life?' is widely credited for having played a crucial role in development of molecular and cellular biology. My essay revisits the issues raised by this book from the modern perspective of epigenetics and systems biology. I contrast two classes of potential mechanisms of epigenetic stability: 'epigenetic templating' and 'systems biology' approaches, and consider them from the point of view expressed by Schroedinger. I also discuss how quantum entanglement, a nonclassical feature of quantum mechanics, can help to address the 'problem of small numbers' that led Schroedinger to promote the idea of a molecular code-script for explaining the stability of biological order.
Schroedinger equation for bosons and fermions
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Kaniadakis, G. [Politecnico di Torino (Italy). Dipt. di Fisica]|[Istituto Nazionale di Fisica della Materia, Unita del Politecnico di Torino, Turin (Italy)]|[Istituto Nazionale di Fisica Nucleare, Turin (Italy)
1995-10-09
We propose a non-linear Schroedinger equation describing the dynamics of bosons or fermions in an effective external force field. This equation is obtained by quantization of a stochastic Markovian process obeying a generalized exclusion principle. (orig.).
Spectral Target Detection using Schroedinger Eigenmaps
Dorado-Munoz, Leidy P.
Applications of optical remote sensing processes include environmental monitoring, military monitoring, meteorology, mapping, surveillance, etc. Many of these tasks include the detection of specific objects or materials, usually few or small, which are surrounded by other materials that clutter the scene and hide the relevant information. This target detection process has been boosted lately by the use of hyperspectral imagery (HSI) since its high spectral dimension provides more detailed spectral information that is desirable in data exploitation. Typical spectral target detectors rely on statistical or geometric models to characterize the spectral variability of the data. However, in many cases these parametric models do not fit well HSI data that impacts the detection performance. On the other hand, non-linear transformation methods, mainly based on manifold learning algorithms, have shown a potential use in HSI transformation, dimensionality reduction and classification. In target detection, non-linear transformation algorithms are used as preprocessing techniques that transform the data to a more suitable lower dimensional space, where the statistical or geometric detectors are applied. One of these non-linear manifold methods is the Schroedinger Eigenmaps (SE) algorithm that has been introduced as a technique for semi-supervised classification. The core tool of the SE algorithm is the Schroedinger operator that includes a potential term that encodes prior information about the materials present in a scene, and enables the embedding to be steered in some convenient directions in order to cluster similar pixels together. A completely novel target detection methodology based on SE algorithm is proposed for the first time in this thesis. The proposed methodology does not just include the transformation of the data to a lower dimensional space but also includes the definition of a detector that capitalizes on the theory behind SE. The fact that target pixels and
Philosophy of Erwin Schroedinger: a diachronic view of Schroedinger's thoughts
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Melgar, M.F.
1988-03-01
There is no agreement within the scientific community about the philosophy of Schroedinger. Some people think that he was a realist, while others defend him as an idealist. In this paper we study a number of Schroedinger's works and we show that the epithets of realist and idealist do not do him justice. Toward the end we conclude that it would be more adequate to place him in the trend known as the philosophy of immanence.
A reliable treatment for nonlinear Schroedinger equations
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Khani, F. [Department of Mathematics, Ilam University, PO Box 69315516, Ilam (Iran, Islamic Republic of); Department of Mathematics, Bakhtar Institute of Higher Education, PO Box 696, Ilam (Iran, Islamic Republic of)], E-mail: farzad_khani59@yahoo.com; Hamedi-Nezhad, S. [Department of Mathematics, Bakhtar Institute of Higher Education, PO Box 696, Ilam (Iran, Islamic Republic of)], E-mail: s_hamedi2001@yahoo.com; Molabahrami, A. [Department of Mathematics, Ilam University, PO Box 69315516, Ilam (Iran, Islamic Republic of)], E-mail: a_m_bahrami@yahoo.com
2007-11-12
Exp-function method is used to find a unified solution of nonlinear wave equation. Nonlinear Schroedinger equations with cubic and power law nonlinearity are selected to illustrate the effectiveness and simplicity of the method. It is shown that the Exp-function method, with the help of symbolic computation, provides a powerful mathematical tool for solving nonlinear equation.
Schroedinger upper bounds to semirelativistic eigenvalues
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Hall, Richard L [Department of Mathematics and Statistics, Concordia University, 1455 de Maisonneuve Boulevard West, Montreal, Quebec, H3G 1M8 (Canada); Lucha, Wolfgang [Institut fuer Hochenergiephysik, Oesterreichische Akademie der Wissenschaften, Nikolsdorfergasse 18, A-1050 Vienna (Austria)
2005-09-16
Problems posed by semirelativistic Hamiltonians of the form H = {radical}(m{sup 2} + p{sup 2}) + V(r) are studied. It is shown that energy upper bounds can be constructed in terms of certain related Schroedinger operators; these bounds include free parameters which can be chosen optimally.
Orbital stability of standing waves for some nonlinear Schroedinger equations
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Cazenave, T.; Lions, P.L.
1982-08-01
We present a general method which enables as to prove the orbital stability of some standing waves in nonlinear Schroedinger equations. For example, we treat the cases of nonlinear Schroedinger equations arising in laser beams, of time-dependent Hartree equations.
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Asselmeyer, T.
1997-12-22
First we introduce a simple model for the description of evolutionary algorithms, which is based on 2nd order partial differential equations for the distribution function of the individuals. Then we turn to the properties of Boltzmann's and Darwin's strategy. the next chapter is dedicated to the mathematical properties of Schroedinger operators. Both statements on the spectral density and their reproducibility during the simulation are summarized. The remaining of this chapter are dedicated to the analysis of the kernel as well as the dependence of the Schroedinger operator on the potential. As conclusion from the results of this chapter we obtain the classification of the strategies in dependence of the fitness. We obtain the classification of the evolutionary strategies, which are described by a 2nd order partial differential equation, in relation to their solution behaviour. Thereafter we are employed with the variation of the mutation distribution.
Cubic nonlinear Schroedinger equation with vorticity
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Caliari, M; Morato, L M; Zuccher, S [Dipartimento di Informatica, Universita di Verona, Ca' Vignal 2, Strada Le Grazie 15, 37134 Verona (Italy); Loffredo, M I [Dipartimento di Scienze Matematiche ed Informatiche, Universita di Siena, Pian dei Mantellini 44, 53100 Siena (Italy)], E-mail: marco.caliari@univr.it, E-mail: loffredo@unisi.it, E-mail: laura.morato@univr.it, E-mail: zuccher@sci.univr.it
2008-12-15
In this paper, we introduce a new class of nonlinear Schroedinger equations (NLSEs), with an electromagnetic potential (A,{phi}), both depending on the wavefunction {psi}. The scalar potential {phi} depends on |{psi}|{sup 2}, whereas the vector potential A satisfies the equation of magnetohydrodynamics with coefficient depending on {psi}. In Madelung variables, the velocity field comes to be not irrotational in general and we prove that the vorticity induces dissipation, until the dynamical equilibrium is reached. The expression of the rate of dissipation is common to all NLSEs in the class. We show that they are a particular case of the one-particle dynamics out of dynamical equilibrium for a system of N identical interacting Bose particles, as recently described within stochastic quantization by Lagrangian variational principle. The cubic case is discussed in particular. Results of numerical experiments for rotational excitations of the ground state in a finite two-dimensional trap with harmonic potential are reported.
Diophantine approximation and the solubility of the Schroedinger equation
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Kristensen, Simon
2003-07-21
We characterise the set of periods for which number theoretical obstructions prevent us from finding periodic solutions of the Schroedinger equation on a two-dimensional torus as well as the asymptotic occurrence of possible resonances.
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Tong Xiaomin [Cold Trapped Ions Project, ICORP, Japan Science and Technology Corporation (JST), Axis 3F, 1-40-2 Fuda Chofu, Tokyo 182-0024 (Japan)]. E-mail: tong@hci.jst.go.jp; Kato, Daiji; Watanabe, Tsutomu [Cold Trapped Ions Project, ICORP, Japan Science and Technology Corporation (JST), Axis 3F, 1-40-2 Fuda Chofu, Tokyo 182-0024 (Japan); Ohtani, Shunsuke [Cold Trapped Ions Project, ICORP, Japan Science and Technology Corporation (JST), Axis 3F, 1-40-2 Fuda Chofu, Tokyo 182-0024 (Japan); University of Electro-Communication, Chofu, Tokyo 182-0021 (Japan)
2000-12-28
We have studied the charge capture and impact excitation processes in H{sup +} on He{sup +} collisions over a wide range of collision energies by solving the time-dependent Schroedinger equation with the classical trajectory approximation for the projectile. The time-dependent Schroedinger equation is solved by the split-operator method with a generalized pseudospectral (non-uniform grid) method in the energy representation. The calculated charge capture cross sections are in good agreement with the available experimental measurements. Our calculated charge capture and impact excitation cross sections are also in reasonable agreement with various close-coupling calculations. Combined with time-dependent density functional theory, our Schroedinger equation method (time propagation) holds significant promise for studying many-electron processes in atom-ion collisions. (author)
Random discrete Schroedinger operators from random matrix theory
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Breuer, Jonathan [Institute of Mathematics, Hebrew University of Jerusalem, Jerusalem 91904 (Israel); Forrester, Peter J [Department of Mathematics and Statistics, University of Melbourne, Parkville, Vic 3010 (Australia); Smilansky, Uzy [Department of Physics of Complex Systems, Weizmann Institute, Rehovot 76100 (Israel)
2007-02-02
We investigate random, discrete Schroedinger operators which arise naturally in the theory of random matrices, and depend parametrically on Dyson's Coulomb gas inverse temperature {beta}. They are similar to the class of 'critical' random Schroedinger operators with random potentials which diminish as vertical bar x vertical bar{sup -1/2}. We show that as a function of {beta} they undergo a transition from a regime of (power-law) localized eigenstates with a pure point spectrum for {beta} < 2 to a regime of extended states with a singular continuous spectrum for {beta} {>=} 2. (fast track communication)
Intertwining operator method and supersymmetry for effective mass Schroedinger equations
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Suzko, A.A. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); JIPENP, National Academy of Sciences of Belarus, Minsk (Belarus)], E-mail: suzko@cv.jinr.ru; Schulze-Halberg, A. [Mathematics Department, University of Colima, Bernal Diaz del Castillo 340, Colima 28045 (Mexico)], E-mail: xbat@ucol.mx
2008-09-08
By application of the intertwining operator method to Schroedinger equations with position-dependent (effective) mass, we construct Darboux transformations, establish the supersymmetry factorization technique and show equivalence of both formalisms. Our findings prove equivalence of the intertwining technique and the method of point transformations.
Evaluation of eigenvalues of a smooth potential via Schroedinger ...
Indian Academy of Sciences (India)
Evaluation of eigenvalues of a smooth potential via Schroedinger transmission across multi-step potential. BASUDEB SAHU1,∗, BIDHUBHUSAN SAHU1 and SANTOSH K AGARWALLA2. 1Department of Physics, North Orissa University, Baripada 757 003, India. 2Department of Applied Physics and Ballistics, Fakir Mohan ...
Ehrenfest theorem, Galilean invariance and nonlinear Schroedinger equations
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Kaelbermann, G [Soil and Water Department, Faculty of Agriculture, Rehovot 76100 (Israel)
2004-02-25
We prove that Galilean invariant Schroedinger equations derived from Lagrangian densities necessarily obey the Ehrenfest theorem for velocity-independent potentials. The conclusion holds as well for Lagrangians describing nonlinear self-interactions. An example of Doebner and Goldin motivates the result.
Solution of the Schroedinger equation in two and three dimensions
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Hajj, F.Y. (National Council for Scientific Research, Beirut (Lebanon))
1985-01-14
Eigenvalues and eigenfunctions of the Schroedinger equation are computed by a finite-difference method that is very simple and fast. In two dimensions, the ground state of helium and that of the hydride ion are computed in the S-limit approximation. In three dimensions, the computations include the ground state of the unapproximated helium atom and that of the lithium atom in the S-limit approximation.
Schroedinger invariant solutions of type IIB with enhanced supersymmetry
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Donos, Aristomenis [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gauntlett, Jerome P. [Imperial College, London (United Kingdom). Theoretical Physics Group; Imperial College, London (United Kingdom). Inst. for Mathematical Sciences
2009-07-15
We construct the Killing spinors for a class of supersymmetric solutions of type IIB supergravity that are invariant under the non-relativistic Schroedinger algebra. The solutions depend on a five-dimensional Sasaki- Einstein space and it has been shown that they admit two Killing spinors. Here we will show that, for generic Sasaki-Einstein space, there are special subclasses of solutions which admit six Killing spinors and we determine the corresponding superisometry algebra. We also show that for the special case that the Sasaki-Einstein space is the round five-sphere, the number of Killing spinors can be increased to twelve. (orig.)
Numerical stochastic perturbation theory in the Schroedinger functional
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Brambilla, Michele; Di Renzo, Francesco; Hesse, Dirk [Parma Univ. (Italy); INFN, Parma (Italy); Dalla Brida, Mattia [Trinity College Dublin (Ireland). School of Mathematics; Sint, Stefan [Trinity College Dublin (Ireland). School of Mathematics; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC
2013-11-15
The Schroedinger functional (SF) is a powerful and widely used tool for the treatment of a variety of problems in renormalization and related areas. Albeit offering many conceptual advantages, one major downside of the SF scheme is the fact that perturbative calculations quickly become cumbersome with the inclusion of higher orders in the gauge coupling and hence the use of an automated perturbation theory framework is desirable. We present the implementation of the SF in numerical stochastic perturbation theory (NSPT) and compare first results for the running coupling at two loops in pure SU(3) Yang-Mills theory with the literature.
A new method for the solution of the Schroedinger equation
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Amore, Paolo [Facultad de Ciencias, Universidad de Colima, Bernal DIaz del Castillo 340, Colima, Colima (Mexico); Aranda, Alfredo [Facultad de Ciencias, Universidad de Colima, Bernal DIaz del Castillo 340, Colima, Colima (Mexico); De Pace, Arturo [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P Giuria 1, I-10125, Torino (Italy)
2004-03-12
We present a new method for the solution of the Schroedinger equation applicable to problems of a non-perturbative nature. The method works by identifying three different scales in the problem, which then are treated independently: an asymptotic scale, which depends uniquely on the form of the potential at large distances; an intermediate scale, still characterized by an exponential decay of the wavefunction; and, finally, a short distance scale, in which the wavefunction is sizable. The notion of optimized perturbation is then used in the last two regimes. We apply the method to the quantum anharmonic oscillator and find it suitable to treat both energy eigenvalues and wavefunctions, even for strong couplings.
Asymptotics of weakly collapsing solutions of nonlinear Schroedinger equation
Ovchinnikov, Yu N
2001-01-01
One studied possible types of asymptotic behavior of weakly collapsing solution of the 3-rd nonlinear Schroedinger equation. It is shown that within left brace A, C sub 1 right brace parameter space there are two neighboring lines along which the amplitude of oscillation terms is exponentially small as to C sub 1 parameter. The same lines locates values of left brace A, C sub 1 right brace parameters at which the energy is equal to zero. With increase of C sub 1 parameter the accuracy of numerical determination of points with zero energy drops abruptly
Rapidly decaying solutions of the nonlinear Schroedinger equation
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Cazenave, T. (Paris-6 Univ., 75 (France). Lab. d' Analyse Numerique); Weissler, F.B. (ENS, 94 - Cachan (France). Centre de Mathematiques Paris-7 Univ., 94 - Creteil (France). UFR de Sciences)
1992-06-01
We consider global solutions of the nonlinear Schroedinger equation iu{sub t}+{Delta}u={lambda}vertical strokeuvertical stroke{sup {alpha}}u, in R{sup N}, (NLS) where {lambda}{epsilon}R and 0<{alpha}< 4/N-2. In particular, for {alpha}>{alpha}{sub 0}=(2-N+{radical}(N{sup 2}+12N+4))/2N, we show that for every ({phi}{epsilon}H{sup 1}(R{sup N}) such that x{phi}(x){epsilon}L{sup 2}(R{sup N}), the solution of (NLS) with initial value {phi}(x)e{sup i(bvertical} {sup strokexvertical} {sup stroke2/4)} is global and rapidly decaying as t{yields}{infinity} if b is large enough. Furthermore, by applying the pseudo-conformal transformation and studying the resulting nonautonomous nonlinear Schroedinger equation, we obtain both new results and simpler proofs of some known results concerning the scattering theory. In particular, we construct the wave operators for 4/N+2<{alpha}<4/N-2. Also, we establish a low energy scattering theory for the same range of {alpha} and show that, at least for {lambda}<0, the lower bound on {alpha} is optimal. Finally, if {lambda}>0, we prove asymptotic completeness for {alpha}{sub 0}{<=}{alpha}<4/N-2. (orig.).
A numerical study of the Schroedinger-Newton equations
Harrison, R I
2001-01-01
and added perturbations oscillate at frequencies determined by the linear perturbation theory. The higher states are shown to be unstable, emitting scatter and leaving a rescaled ground state. The rate at which they decay is controlled by the complex eigenvalues of the linear perturbation. Next we consider adding another dimension in two different ways: by considering the axisymmetric case and the 2-D equations. The stationary solutions are found. We modify the evolution method and find that the higher states are unstable. In 2-D case we consider rigidly rotating solutions and show they exist and are unstable. The Schroedinger-Newton (S-N) equations were proposed by Penrose [18] as a model for gravitational collapse of the wave-function. The potential in the Schroedinger equation is the gravity due to the density of vertical bar psi vertical bar sup 2 , where psi is the wave-function. As with normal Quantum Mechanics the probability, momentum and angular momentum are conserved. We first consider the spherical...
Soliton-like solutions to the ordinary Schroedinger equation
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Zamboni-Rached, Michel [Universidade Estadual de Campinas (DMO/FEEC/UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Eletrica e de Computacao. Dept. de Microondas e Optica; Recami, Erasmo, E-mail: recami@mi.infn.i [Universita Statale di Bergamo, Bergamo (Italy). Facolta di Ingegneria
2011-07-01
In recent times it has been paid attention to the fact that (linear) wave equations admit of soliton-like solutions, known as Localized Waves or Non-diffracting Waves, which propagate without distortion in one direction. Such Localized Solutions (existing also for K-G or Dirac equations) are a priori suitable, more than Gaussian's, for describing elementary particle motion. In this paper we show that, mutatis mutandis, Localized Solutions exist even for the ordinary Schroedinger equation within standard Quantum Mechanics; and we obtain both approximate and exact solutions, also setting forth for them particular examples. In the ideal case such solutions bear infinite energy, as well as plane or spherical waves: we show therefore how to obtain nite-energy solutions. At last, we briefly consider solutions for a particle moving in the presence of a potential. (author)
From qubits and actions to the Pauli-Schroedinger equation
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Mizrahi, Salomon S [Departamento de Fisica, Universidade Federal de Sao Carlos, Caixa Postal 676, Sao Carlos, 13565-905 Sao Paulo (Brazil)], E-mail: salomon@df.ufscar.br
2009-07-15
Here I show that a classical or quantum bit state plus one simple operation, an action, are sufficient ingredients to derive a quantum dynamical equation that rules the sequential changes of the state. Then, by assuming that a freely moving massive particle is the qubit carrier, it is found that both, the particle position in physical space and the qubit state, change in time according to the Pauli-Schroedinger equation. So, this approach suggests the following conjecture: because it carries one qubit of information the particle motion has its description enslaved by the very existence of the internal degree of freedom. It is compelled to be described no more classically but by a wavefunction. I also briefly discuss the Dirac equation in terms of qubits.
The Schroedinger functional for Gross-Neveu models
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Leder, B.
2007-04-18
Gross-Neveu type models with a finite number of fermion flavours are studied on a two-dimensional Euclidean space-time lattice. The models are asymptotically free and are invariant under a chiral symmetry. These similarities to QCD make them perfect benchmark systems for fermion actions used in large scale lattice QCD computations. The Schroedinger functional for the Gross-Neveu models is defined for both, Wilson and Ginsparg-Wilson fermions, and shown to be renormalisable in 1-loop lattice perturbation theory. In two dimensions four fermion interactions of the Gross-Neveu models have dimensionless coupling constants. The symmetry properties of the four fermion interaction terms and the relations among them are discussed. For Wilson fermions chiral symmetry is explicitly broken and additional terms must be included in the action. Chiral symmetry is restored up to cut-off effects by tuning the bare mass and one of the couplings. The critical mass and the symmetry restoring coupling are computed to second order in lattice perturbation theory. This result is used in the 1-loop computation of the renormalised couplings and the associated beta-functions. The renormalised couplings are defined in terms of suitable boundary-to-boundary correlation functions. In the computation the known first order coefficients of the beta-functions are reproduced. One of the couplings is found to have a vanishing betafunction. The calculation is repeated for the recently proposed Schroedinger functional with exact chiral symmetry, i.e. Ginsparg-Wilson fermions. The renormalisation pattern is found to be the same as in the Wilson case. Using the regularisation dependent finite part of the renormalised couplings, the ratio of the Lambda-parameters is computed. (orig.)
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Amore, Paolo [Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima, Colima (Mexico)], E-mail: paolo.amore@gmail.com; Fernandez, Francisco M. [INIFTA (Conicet, UNLP), Division Quimica Teorica, Diag. 113 y 64 (S/N), Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)], E-mail: fernande@quimica.unlp.edu.ar
2008-04-28
We show that the Riccati-Pade method is suitable for the calculation of the complex eigenvalues of the Schroedinger equation with a repulsive exponential potential. The accuracy of the results is remarkable for realistic potential parameters.
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Kalla, C, E-mail: Caroline.Kalla@u-bourgogne.fr [Institut de Mathematiques de Bourgogne, Universite de Bourgogne, 9 avenue Alain Savary, 21078 Dijon (France)
2011-08-19
We present new solutions in terms of elementary functions of the multi-component nonlinear Schroedinger equations and known solutions of the Davey-Stewartson equations such as multi-soliton, breather, dromion and lump solutions. These solutions are given in a simple determinantal form and are obtained as limiting cases in suitable degenerations of previously derived algebro-geometric solutions. In particular, we present for the first time breather and rational breather solutions of the multi-component nonlinear Schroedinger equations.
On the chirally rotated Schroedinger functional with Wilson fermions
Energy Technology Data Exchange (ETDEWEB)
Gonzalez Lopez, Jenifer
2011-05-25
There are many phenomena in nature, which are closely linked to the low energy regime of QCD. From a theoretical point of view, these low energy phenomena can be dealt with only by means of non-perturbative methods. It is the central goal of this thesis to provide a framework for such a nonperturbative renormalization. For that purpose, we employ a 4-dimensional lattice as a regulator of QCD. As a renormalization scheme, we propose a finite volume Schroedinger functional scheme and here in particular, the chirally rotated Schroedinger functional ({chi}SF). We first perform analytical studies of the {chi}SF at tree-level of perturbation theory, in the continuum and on the lattice. We study the eigenvalue spectrum of the continuum Dirac operator, equipped with chirally rotated SF boundary conditions, and derive the corresponding quark propagator. We then determine the tree-level quark propagator on the lattice, employing massless Wilson fermions as a regulator of the theory. Beyond tree-level, all studies are performed in the quenched approximation of QCD, as a first, computationally much simpler step to understand the properties of the newly proposed {chi}SF scheme. One of the main targets of the present work, has been to perform the non-perturbative tuning of the two required coefficients of the {chi}SF scheme, such that a well defined continuum limit can be reached. We demonstrate, as the first main result of this thesis, that the tuning is feasible and that, moreover, physical quantities are insensitive to the particular tuning condition. As in any lattice regularization with SF-like boundary conditions, there are also in the {chi}SF a couple of counterterms at the boundaries, whose coefficients need to be tuned in order to remove the O(a) discretization effects originated at the boundaries. However, besides these boundary O(a) effects, the {chi}SF is expected to be compatible with bulk automatic O(a)-improvement. We show here that, indeed, the scaling behavior
Study of nonlinear waves described by the cubic Schroedinger equation
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Walstead, A.E.
1980-03-12
The cubic Schroedinger equation (CSE) is ubiquitous as a model equation for the long-time evolution of finite-amplitude near-monochromatic dispersive waves. It incorporates the effects of the radiation field pressure on the constitutive properties of the supporting medium in a self-consistent manner. The properties of the uniformly transiating periodic wave solutions of the one-dimensional CSE are studied here. These (so-called cnoidal) waves are characterized by the values of four parameters. Whitham's averaged variational principle is used to derive a system of quasilinear evolution equations (the modulational equations) for the values of these parameters when they are slowly varying in space and time. Explicit expressions for the characteristic velocities of the modulational equations are obtained for the full set of cnoidal waves. Riemann invariants are obtained for several limits for the stable case, and growth rates are obtained for several limits, including the solitary wave chain, for the unstable case. The results for several nontrivial limiting cases agree with those obtained by independent methods by others. The dynamics of the CSE generalized to two spatial dimensions are studied for the unstable case. A large class of similarity solutions with cylindrical symmetry are obtained systematically using infinitesimal transformation group techniques. The methods are adapted to obtain the symmetries of the action functional of the CSE and to deduce nine integral invariants. A numerical study of the self-similar solutions reveals that they are modulationally unstable and that singularities dominate the dynamics of the CSE in two dimensions. The CSE is derived using perturbation theory for a specific problem in plasma physics: the evolution of the envelope of a near-monochromatic electromagnetic wave in a cold magnetized plasma. 13 figures, 2 tables.
Solitons on nanotubes and fullerenes as solutions of a modified non-linear Schroedinger equation
Brihaye, Yves; Hartmann, Betti
2004-01-01
Fullerenes and nanotubes consist of a large number of carbon atoms sitting on the sites of a regular lattice. For pratical reasons it is often useful to approximate the equations on this lattice in terms of the continuous equation. At the moment, the best candidate for such an equation is the modified non-linear Schroedinger equation. In this paper, we study the modified non-linear Schroedinger equation, which arises as continuous equation in a system describing an excitation on a hexagonal l...
Analytical solutions to a class of nonlinear Schroedinger equations with PT-like potentials
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Musslimani, Ziad H [Department of Mathematics, Florida State University, Tallahassee, 32306-4510 FL (United States); Makris, Konstantinos G; El-Ganainy, Ramy; Christodoulides, Demetrios N [College of Optics and Photonics-CREOL, University of Central Florida, Orlando, 32816 FL (United States)
2008-06-20
We present closed form solutions to a certain class of one- and two-dimensional nonlinear Schroedinger equations involving potentials with broken and unbroken PT symmetry. In the one-dimensional case, these solutions are given in terms of Jacobi elliptic functions, hyperbolic and trigonometric functions. Some of these solutions are possible even when the corresponding PT-symmetric potentials have a zero threshold. In two-dimensions, hyperbolic secant type solutions are obtained for a nonlinear Schroedinger equation with a non-separable complex potential.
Blow-up in nonlinear Schroedinger equations. I. A general review
DEFF Research Database (Denmark)
Juul Rasmussen, Jens; Rypdal, K.
1986-01-01
The general properties of a class of nonlinear Schroedinger equations: iut + p:∇∇u + f(|u|2)u = 0 are reviewed. Conditions for existence, uniqueness, and stability of solitary wave solutions are presented, along with conditions for blow-up and global existence for the Cauchy problem.......The general properties of a class of nonlinear Schroedinger equations: iut + p:∇∇u + f(|u|2)u = 0 are reviewed. Conditions for existence, uniqueness, and stability of solitary wave solutions are presented, along with conditions for blow-up and global existence for the Cauchy problem....
Path integral representations on the complex sphere
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Grosche, C. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2007-08-15
In this paper we discuss the path integral representations for the coordinate systems on the complex sphere S{sub 3C}. The Schroedinger equation, respectively the path integral, separates in exactly 21 orthogonal coordinate systems. We enumerate these coordinate systems and we are able to present the path integral representations explicitly in the majority of the cases. In each solution the expansion into the wave-functions is stated. Also, the kernel and the corresponding Green function can be stated in closed form in terms of the invariant distance on the sphere, respectively on the hyperboloid. (orig.)
Asymptotic stability of multi-soliton solutions for nonlinear Schroedinger eqations
Perelman, G.
2003-01-01
We consider the Cauchy problem for the nonlinear Schroedinger eqiation with initial data close to a sum of N decoupled solitons. Under some suitable assumptions on the spectral structure of the one soliton linearizations we prove that for large time the asymptotics of the solution is given by a sum of solitons with slightly modified parameters and a small dispersive term.
Solutions of type IIB and D=11 supergravity with Schroedinger(z) symmetry
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Donos, Aristomenis [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gauntlett, Jerome P. [Imperial College, London (United Kingdom). Theoretical Physics Group; Imperial College, London (United Kingdom). Inst. for Mathematical Sciences
2009-05-15
We construct families of supersymmetric solutions of type IIB and D=11 supergravity that are invariant under the non-relativistic Schroedinger(z) algebra for various values of the dynamical exponent z. The new solutions are based on five- and seven-dimensional Sasaki-Einstein manifolds, respectively, and include supersymmetric solutions with z=2. (orig.)
A study on the d-dimensional Schroedinger equation with a power-law nonlinearity
Energy Technology Data Exchange (ETDEWEB)
Shidfar, A. [Department of Mathematics, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)], E-mail: shidfar@iust.ac.ir; Molabahrami, A. [Department of Mathematics, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Department of Mathematics, Ilam University, PO Box 69315516, Ilam (Iran, Islamic Republic of)], E-mail: a_m_bahrami@iust.ac.ir; Babaei, A.; Yazdanian, A. [Department of Mathematics, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)
2009-11-30
In this paper, the homotopy perturbation method (HPM) is applied to obtain series pattern solutions of the Cauchy problem for the d-dimensional Schroedinger equation with a power-law nonlinearity. We introduce the recurrent relation to solve the mentioned Cauchy problem. For some cases of given initial condition, we obtain the closed form of the exact solutions.
Magnetic virial identities and applications to blow-up for Schroedinger and wave equations
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Garcia, Andoni, E-mail: andoni.garcia@ehu.es [Departamento de Matematicas, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain)
2012-01-13
We prove blow-up results for the solution of the initial-value problem with negative energy of the focusing mass-critical and supercritical nonlinear Schroedinger and the focusing energy-subcritical nonlinear wave equations with electromagnetic potential. (paper)
The solution of the Schroedinger equation for complex Hamiltonian systems in two dimensions
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Chand, Fakir [Department of Physics, Kurukshetra University, Kurukshetra-136 119, Haryana (India); Singh, Ram Mehar [Department of Physics, Haryana College of Technology and Management, Kaithal-136 027, Haryana (India); Kumar, Narender [Department of Physics, Kurukshetra University, Kurukshetra-136 119, Haryana (India); Mishra, S C [Department of Physics, Kurukshetra University, Kurukshetra-136 119, Haryana (India)
2007-08-17
We investigate the ground state solutions of the Schroedinger equation for complex (non-Hermitian) Hamiltonian systems in two dimensions within the framework of an extended complex phase-space approach. The eigenvalues and eigenfunctions of some two-dimensional complex potentials are found.
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Kozlowski, K.K.
2010-12-15
Starting from the form factor expansion in finite volume, we derive the multidimensional generalization of the so-called Natte series for the zero-temperature, time and distance dependent reduced density matrix in the non-linear Schroedinger model. This representation allows one to read-off straightforwardly the long-time/large-distance asymptotic behavior of this correlator. Our method of analysis reduces the complexity of the computation of the asymptotic behavior of correlation functions in the so-called interacting integrable models, to the one appearing in free fermion equivalent models. We compute explicitly the first few terms appearing in the asymptotic expansion. Part of these terms stems from excitations lying away from the Fermi boundary, and hence go beyond what can be obtained by using the CFT/Luttinger liquid based predictions. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Kozlowski, K.K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Terras, V. [CNRS, ENS Lyon (France). Lab. de Physique
2010-12-15
We present a new method allowing us to derive the long-time and large-distance asymptotic behavior of the correlations functions of quantum integrable models from their exact representations. Starting from the form factor expansion of the correlation functions in finite volume, we explain how to reduce the complexity of the computation in the so-called interacting integrable models to the one appearing in free fermion equivalent models. We apply our method to the time-dependent zero-temperature current-current correlation function in the non-linear Schroedinger model and compute the first few terms in its asymptotic expansion. Our result goes beyond the conformal field theory based predictions: in the time-dependent case, other types of excitations than the ones on the Fermi surface contribute to the leading orders of the asymptotics. (orig.)
Boson--Fermion hybrid representation formulation, I
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Wu, C.; Feng, D.H.
1981-08-01
A boson--fermion hybrid representation is presented. In this framework, a fermion system is described concurrently by the bosonic and the fermonic degrees of freedom. A fermion pair in this representation can be treated as a boson without violating the Pauli principle. Furthermore the ''bosonic interactions'' are shown to originate from the exchange processes of the fermions and can be calculated from the original fermion interactions. Both the formulation of the BFH representations for the even and odd nuclear systems are given. We find that the basic equation of the nuclear field theory (NFT) is just the usual Schroedinger equation in such a representation with the empirical NFT diagrammatic rules emerging naturally. This theory was numerically checked in the case of four nucleons moving in a single-j shell and the exactness of the theory was established.
On the effect of random inhomogeneities in Kerr media modelled by a nonlinear Schroedinger equation
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Villarroel, Javier [Facultad de Ciencias, Universidad de Salamanca, Plaza Merced s/n, E-37008 Salamanca (Spain); Montero, Miquel, E-mail: javier@usal.e, E-mail: miquel.montero@ub.ed [Departament de FIsica Fonamental, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain)
2010-07-14
We consider the propagation of optical beams under the interplay of dispersion and Kerr nonlinearity in optical fibres with impurities distributed at random uniformly on the fibre. By using a model based on the nonlinear Schroedinger equation we clarify how such inhomogeneities affect different aspects such as the number of solitons present and the intensity of the signal. We also obtain the mean distance for the signal to dissipate to a given level.
Baecklund transformations and exact soliton solutions for nonlinear Schroedinger-type equations
Energy Technology Data Exchange (ETDEWEB)
Khater, A. H. [Cairo Univ. (Egypt). Faculty of science, Dept. of Mathematics]|[Antwerp Univ. (Belgium). Dept. of Physics; Callebaut, D. K. [Antwerp Univ. (Belgium). Dept. of Physics; El-Kalaawy, O. H. [Cairo Univ. (Egypt). Faculty of science, Dept. of Mathematics
1998-09-01
Using the Baecklund transformations (BTs) and the Darboux-Bargmann technique, the Authors consider the nonlinear Schroedinger-type (NLS-type) equations solvable by the inverse scattering method of Zakharov-Shabat/Ablowitz-Kaup-Newell-Segur (ZS/AKNS) system and the ZS/AKNS wave functions corresponding to the soliton solutions of NLS-type equations. Thus, families of new soliton solutions for NLS- type equations are obtained.
General soliton solutions of an n-dimensional nonlinear Schroedinger equation
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Khater, A. H.; Seadawy, A. R. [Cairo Univ., Cairo (Egypt). Faculty of Science, Mathematics Dept.; Helal, M. A. [Cairo Univ., Cairo (Egypt). Faculty of Science, Mathematics Dept.
2000-11-01
Applying the function transformation method, an n-dimensional nonlinear Schroedinger (NDNLS) equation is transformed into a sinh-Gordon equation and other equations, which depend only on one function {zeta} leads to a general soliton solution of the NDNLS equation. It contains some interesting specific solutions such as the N multiple solitons, the propagational breathers and the quadric solitons. Their properties are simply discussed.
Instability of stationary states in nonlinear Schroedinger or Klein-Gordon equations
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Berestycki, H.; Cazenave, T. (Universite Pierre et Marie Curie, Paris (France))
1981-11-09
In this note, we prove the instability of stationary states for the Schroedinger equation and for the Klein-Gordon equation. Here, u(x) is a ground state solution of the nonlinear scalar field equation -..delta..u+..omega..u=g(u) in Rsup(N). Indeed, under certain assumptions on g, we show that there exist initial conditions, arbitrarily close to the stationary states, such that the solutions of these equations blow up in finite time.
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Chow, K.W. [Department of Mechanical Engineering, University of Hong Kong, Pokfulam, Hong Kong (China)]. E-mail: kwchow@hkusua.hku.hk; Conte, Robert [Service de Physique de l' etat Condense (URA 2464), CEA-Saclay, F-91191 Gif-sur-Yvette Cedex (France)]. E-mail: conte@drecam.saclay.cea.fr; Xu, Neil [Department of Mathematics, California Institute of Technology, Pasadena, CA 91125 (United States)]. E-mail: naijie@caltech.edu
2006-01-23
We derive two new solutions in terms of elliptic functions, one for the dark and one for the bright soliton regime, for the semi-discrete cubic nonlinear Schroedinger equation of Ablowitz and Ladik. When considered in the complex plane, these two solutions are identical. In the continuum limit, they reduce to known elliptic function solutions. In the long wave limit, the dark one reduces to the collision of two discrete dark solitons, and the bright one to a discrete breather.
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Palombi, Filippo [' E. Fermi' Research Center, c/o Compendio Viminale - pal. F, I-00184 Rome (Italy); Pena, Carlos [DESY, Theory Group, Notkestrasse 85, D-22603 Hamburg (Germany); Sint, Stefan [Departamento de Fisica Teorica C-XI and Instituto de Fisica Teorica C-XVI, Universidad Autonoma de Madrid, Cantoblanco, E-28049 Madrid (Spain)
2005-03-15
Renormalization constants for multiplicatively renormalizable parity-odd four-fermion operators are computed in various different Schroedinger Functional (SF) schemes and lattice regularizations with Wilson quarks at one-loop order in perturbation theory. Our results are used in the calculation of their NLO anomalous dimensions, through matching to continuum schemes. They also enable a comparison of the two-loop perturbative RG running to the previously obtained nonperturbative one in the region of small renormalized coupling.
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Lopez, J. Gonzalez [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Renner, D.B. [Jefferson Lab, Newport News, VA (United States); Shindler, A. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik
2012-08-24
In a previous paper (J. G. Lopez et al.,2012) we have discussed the non-perturbative tuning of the chirally rotated Schroedinger functional ({chi}SF). This tuning is required to eliminate bulk O(a) cutoff effects in physical correlation functions. Using our tuning results obtained in this paper we perform scaling and universality tests analyzing the residual O(a) cutoff effects of several step-scaling functions and we compute renormalization factors at the matching scale. As an example of possible application of the {chi}SF we compute the renormalized strange quark mass using large volume data obtained from Wilson twisted mass fermions at maximal twist. (orig.)
Some Exact Results for the Schroedinger Wave Equation with a Time Dependent Potential
Campbell, Joel
2009-01-01
The time dependent Schroedinger equation with a time dependent delta function potential is solved exactly for many special cases. In all other cases the problem can be reduced to an integral equation of the Volterra type. It is shown that by knowing the wave function at the origin, one may derive the wave function everywhere. Thus, the problem is reduced from a PDE in two variables to an integral equation in one. These results are used to compare adiabatic versus sudden changes in the potential. It is shown that adiabatic changes in the p otential lead to conservation of the normalization of the probability density.
Some exact results for the Schroedinger wave equation with a time-dependent potential
Energy Technology Data Exchange (ETDEWEB)
Campbell, Joel [NASA Langley Research Center, MS 488, Hampton, VA 23681 (United States)], E-mail: joel.f.campbell@nasa.gov
2009-09-11
The time-dependent Schroedinger equation with a time-dependent delta function potential is solved exactly for many special cases. In all other cases the problem can be reduced to an integral equation of the Volterra type. It is shown that by knowing the wavefunction at the origin, one may derive the wavefunction everywhere. Thus, the problem is reduced from a PDE in two variables to an integral equation in one. These results are used to compare adiabatic versus sudden changes in the potential. It is shown that adiabatic changes in the potential lead to the conservation of the normalization of the probability density.
Energy Technology Data Exchange (ETDEWEB)
Lopez, J. Gonzalez [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Renner, D.B. [Jefferson Lab, Newport News, VA (United States); Shindler, A. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik
2012-08-23
The use of chirally rotated boundary conditions provides a formulation of the Schroedinger functional that is compatible with automatic O(a) improvement of Wilson fermions up to O(a) boundary contributions. The elimination of bulk O(a) effects requires the non-perturbative tuning of the critical mass and one additional boundary counterterm. We present the results of such a tuning in a quenched setup for several values of the renormalized gauge coupling, from perturbative to nonperturbative regimes, and for a range of lattice spacings. We also check that the correct boundary conditions and symmetries are restored in the continuum limit. (orig.)
Protogenov, A P
2001-01-01
The brief review of events, conditioned by the nonlinear modes strong correlations in the planar systems is presented. The analysis is limited by the Schroedinger nonlinear equation model. The fields stationary distributions are determined. The dependence of the particles number on the parameter characterizing the degree of looking, of the universal oscillation lines, is obtained. It is shown that by small values of this parameter there exists on the two-dimensional lattice the universal gravitation, which may be the dynamic cause of transition to the coherent state. The connection of the chiral nonlinear boundary modes with the violations of the Galilean-invariance of the considered system is discussed
Blow-up in nonlinear Schroedinger equations. II. Similarity structure of the blow-up singularity
DEFF Research Database (Denmark)
Rypdal, K.; Juul Rasmussen, Jens
1986-01-01
A critical review of the literature on similarity solutions of nonlinear Schroedinger equations is presented. We demonstrate that the self-similar blow-up solutions discovered hitherto are all associated either with a simple stretching invariance, or with a slightly more complicated conformal...... invariance and generalizations of the latter. This generalized "quasi-invariance" reveals the nature of the blow-up singularity and resolves an old controversy. Most of the previous work has been done on the cubic nonlinearity. We generalize the results to an arbitrary power nonlinearity....
Cole-Hopf-like transformation for Schroedinger equations containing complex nonlinearities
Energy Technology Data Exchange (ETDEWEB)
Kaniadakis, G.; Scarfone, A.M. [Dipartimento di Fisica, Politecnico di Torino, Torino (Italy) and Istituto Nazionale di Fisica della Materia, Unita del Politecnico di Torino, Torino (Italy)]. E-mails: kaniadakis@polito.it; scarfone@polito.it
2002-03-01
We consider systems which conserve the particle number and are described by Schroedinger equations containing complex nonlinearities. In the case of canonical systems, we study their main symmetries and conservation laws. We introduce a Cole-Hopf-like transformation both for canonical and noncanonical systems, which changes the evolution equation into another one containing purely real nonlinearities, and reduces the continuity equation to the standard form of the linear theory. This approach allows us to treat, in a unifying scheme, a wide variety of canonical and noncanonical nonlinear systems, some of them already known in the literature. (author)
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Kravchenko, Viktor G [Faculdade de Ciencias y Tecnologia, Universidade do Algarve, Campus de Gambelas, 8000 Faro (Portugal); Kravchenko, Vladislav V [Depto de Telecomunicaciones, SEPI ESIME Zacatenco, Instituto Politecnico Nacional, Av. IPN S/N, Edif. 1 CP 07738, DF (Mexico)
2003-11-07
We show that an ample class of physically meaningful partial differential systems of first order such as the Dirac equation with different one-component potentials, static Maxwell's system and the system describing the force-free magnetic fields are equivalent to a single quaternionic equation which in its turn reduces in general to a Schroedinger equation with quaternionic potential, and in some situations this last can be diagonalized. The rich variety of methods developed for different problems corresponding to the Schroedinger equation can be applied to the systems considered in the present work.
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Hesse, Dirk
2012-07-13
The author developed the pastor software package for automated lattice perturbation theory calculations in the Schroedinger functional scheme. The pastor code consists of two building blocks, dealing with the generation of Feynman rules and Feynman diagrams respectively. Accepting a rather generic class of lattice gauge and fermion actions, passed to the code in a symbolic form as input, a low level part of pastor will generate Feynman rules to an arbitrary order in the bare coupling with a trivial or an Abelian background field. The second, high level part of pastor is a code generator whose output relies on the vertex generator. It writes programs that evaluate Feynman diagrams for a class of Schroedinger functional observables up to one loop order automatically, the relevant O(a) improvement terms are taken into account. We will describe the algorithms used for implementation of both parts of the code in detail, and provide cross checks with perturbative and non-perturbative data to demonstrate the correctness of our code. We demonstrate the usefulness of the pastor package through various applications taken from the matching process of heavy quark effective theory with quantum chromodynamics. We have e.g. completed a one loop analysis for new candidates for matching observables timely and with rather small effort, highlighting two advantages of an automated software setup. The results that were obtained so far will be useful as a guideline for further non-perturbative studies.
Bell's theorem and quantum realism. Reassessment in light of the Schroedinger paradox
Energy Technology Data Exchange (ETDEWEB)
Shakur, Asif M. [Salisbury Univ., MD (United States). Dept. of Physics; Hemmick, Douglas L.
2012-07-01
Quantum theory presents a strange picture of the world, offering no real account of physical properties apart from observation. Neils Bohr felt that this reflected a core truth of nature: ''There is no quantum world. There is only an abstract mathematical description.'' Among the most significant developments since Bohr's day has been the theorem of John S. Bell. It is important to consider whether Bell's analysis supports such a denial of microrealism. In this book, we evaluate the situation in terms of an early work of Erwin Schroedinger. Doing so, we see how Bell's theorem is conceptually related to the Conway and Kochen Free Will theorem and also to all the major anti-realism efforts. It is easy to show that none of these analyses imply the impossibility of objective realism. We find that Schroedinger's work leads to the derivation of a new series of theoretical proofs and potential experiments, each involving ''entanglement,'' the link between particles in some quantum systems. (orig.)
Phase-space representation of non-classical behaviour of scalar wave-fields
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Canas-Cardona, Gustavo; Castaneda, Roman [Physics School, Universidad Nacional de Colombia Sede Medellin, A.A. 3840 Medellin (Colombia); Vinck-Posada, Herbert, E-mail: gcanas@unal.edu.co [Physics Department, Universidad Nacional de Colombia Sede Bogota, Bogota D.C (Colombia)
2011-01-01
The modelling of optical fields by using radiant and virtual point sources for the spatial coherence wavelets in the phase-space representation evidences some effects, conventionally attributed to non-classical correlations of light, although such type of correlations are not explicitly included in the model. Specifically, a light state is produced that has similar morphology to the Wigner Distribution Function of the well-known quantum Schroedinger cat and squeezed states.
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Cobian, Hector [Facultad de Ciencias, Universidad de Colima, Bernal DIaz del Castillo 340, 28045 Colima, Colima (Mexico); Schulze-Halberg, Axel, E-mail: horus.cobian@gmail.com, E-mail: xbataxel@gmail.com, E-mail: axgeschu@iun.edu [Department of Mathematics and Actuarial Science, Indiana University Northwest, 3400 Broadway, Gary, IN 46408 (United States)
2011-07-15
We construct Darboux transformations for time-dependent Schroedinger equations with position-dependent mass in (2 + 1) dimensions. Several examples illustrate our results, which complement and generalize former findings for the constant mass case in two spatial variables (Schulze-Halberg 2010 J. Math. Phys. 51 033521).
Cahill, Nathan D.; Czaja, Wojciech; Messinger, David W.
2014-06-01
Schroedinger Eigenmaps (SE) has recently emerged as a powerful graph-based technique for semi-supervised manifold learning and recovery. By extending the Laplacian of a graph constructed from hyperspectral imagery to incorporate barrier or cluster potentials, SE enables machine learning techniques that employ expert/labeled information provided at a subset of pixels. In this paper, we show how different types of nondiagonal potentials can be used within the SE framework in a way that allows for the integration of spatial and spectral information in unsupervised manifold learning and recovery. The nondiagonal potentials encode spatial proximity, which when combined with the spectral proximity information in the original graph, yields a framework that is competitive with state-of-the-art spectral/spatial fusion approaches for clustering and subsequent classification of hyperspectral image data.
Energy Technology Data Exchange (ETDEWEB)
Zhong Weiping [Department of Electronic and Information Engineering, Shunde Polytechnic, Guangdong Province, Shunde 528300 (China); Belic, Milivoj [Texas A and M University at Qatar, 23874 Doha (Qatar); Institute of Physics, University of Belgrade, P. O. Box 68, 11001 Belgrade (Serbia); Assanto, Gaetano [NooEL, Nonlinear Optics and OptoElectronics Lab, University of Rome ' ' Roma Tre,' ' I-00146 Rome (Italy); Malomed, Boris A. [Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, E-08860 Castelldefels (Barcelona) (Spain); Huang, Tingwen [Texas A and M University at Qatar, 23874 Doha (Qatar)
2011-10-15
We report approximate analytical solutions to the (3+1)-dimensional spatiotemporal nonlinear Schroedinger equation, with the uniform self-focusing nonlinearity and a variable negative radial diffraction coefficient, in the form of three-dimensional solitons. The model may be realized in artificial optical media, such as left-handed materials and photonic crystals, with the anomalous sign of the group-velocity dispersion (GVD). The same setting may be realized through the interplay of the self-defocusing nonlinearity, normal GVD, and positive variable diffraction. The Hartree approximation is utilized to achieve a suitable separation of variables in the model. Then, an inverse procedure is introduced, with the aim to select a suitable profile of the modulated diffraction coefficient supporting desirable soliton solutions (such as dromions, single- and multilayer rings, and multisoliton clusters). The validity of the analytical approximation and stability of the solutions is tested by means of direct simulations.
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Herbert, J.M.
1997-02-01
Perturbation theory has long been utilized by quantum chemists as a method for approximating solutions to the Schroedinger equation. Perturbation treatments represent a system`s energy as a power series in which each additional term further corrects the total energy; it is therefore convenient to have an explicit formula for the nth-order energy correction term. If all perturbations are collected into a single Hamiltonian operator, such a closed-form expression for the nth-order energy correction is well known; however, use of a single perturbed Hamiltonian often leads to divergent energy series, while superior convergence behavior is obtained by expanding the perturbed Hamiltonian in a power series. This report presents a closed-form expression for the nth-order energy correction obtained using Rayleigh-Schroedinger perturbation theory and a power series expansion of the Hamiltonian.
Energy Technology Data Exchange (ETDEWEB)
Guasti, M Fernandez [Depto de Fisica, CBI, Universidad A Metropolitana - Iztapalapa, 09340 Mexico, DF, Apdo Postal 55-534 (Mexico); Moya-Cessa, H [INAOE, Coordinacion de Optica, Apdo Postal 51 y 216, 72000 Puebla, Pue. (Mexico)
2003-02-28
An extension of the classical orthogonal functions invariant to the quantum domain is presented. This invariant is expressed in terms of the Hamiltonian. Unitary transformations which involve the auxiliary function of this quantum invariant are used to solve the time-dependent Schroedinger equation for a harmonic oscillator with time-dependent parameter. The solution thus obtained is in agreement with the results derived using other methods which invoke the Lewis invariant in their procedures.
Energy Technology Data Exchange (ETDEWEB)
Santillan, M [Cinvestav-IPN, Unidad Monterrey, Parque de Investigacion e Innovacion Tecnologica, Autopista Monterrey-Aeropuerto Km 10, 66600 Apodaca NL (Mexico); Zeron, E S [Departamento de Matematicas, Cinvestav-IPN, 07000 Mexico DF (Mexico); Rio-Correa, J L del [Departamento de Fisica, Universidad Autonoma Metropolitana Iztapalapa, 09340 Mexico DF (Mexico)], E-mail: msantillan@cinvestav.mx, E-mail: eszeron@math.cinvestav.mx, E-mail: jlrc@xanum.uam.mx
2008-05-15
In the traditional statistical mechanics textbooks, the entropy concept is first introduced for the microcanonical ensemble and then extended to the canonical and grand-canonical cases. However, in the authors' experience, this procedure makes it difficult for the student to see the bigger picture and, although quite ingenuous, the subtleness of the demonstrations to pass from the microcanonical to the canonical and grand-canonical ensembles is hard to grasp. In the present work, we adapt the approach used by Schroedinger to introduce the entropy definition for quantum mechanical systems to derive a classical mechanical entropy definition, which is valid for all ensembles and is in complete agreement with the Gibbs entropy. Afterwards, we show how the specific probability densities for the microcanonical and canonical ensembles can be obtained from the system macrostate, the entropy definition and the second law of thermodynamics. After teaching the approach introduced in this paper for several years, we have found that it allows a better understanding of the statistical mechanics foundations. On the other hand, since it demands previous knowledge of thermodynamics and mathematical analysis, in our experience this approach is more adequate for final-year undergraduate and graduate physics students.
Plasmons and Coulomb drag in Dirac/Schroedinger hybrid electron systems
Principi, Alessandro; Carrega, Matteo; Asgari, Reza; Pellegrini, Vittorio; Polini, Marco
2013-03-01
We show that the plasmon spectrum of an ordinary two-dimensional electron gas (2DEG) hosted in a GaAs heterostructure is significantly modified when a graphene sheet is placed on the surface of the semiconductor in close proximity to the 2DEG. Long-range Coulomb interactions between massive electrons and massless Dirac fermions lead to a new set of optical and acoustic intra-subband plasmons. Here we compute the dispersion of these coupled modes within the Random Phase Approximation, providing analytical expressions in the long-wavelength limit that shed light on their dependence on the Dirac velocity and Dirac-fermion density. We also evaluate the resistivity in a Coulomb-drag transport setup. These Dirac/Schroedinger hybrid electron systems are experimentally feasible and open new research opportunities for fundamental studies of electron-electron interaction effects in two spatial dimensions. Work in Pisa was supported by MIUR through the program ``FIRB - Futuro in Ricerca 2010.'' Grant no. RBFR10M5BT (``Plasmons and terahertz devices in graphene'').
An asymptotic solution of the Schroedinger equation for the elliptic wire in the magnetic field
Energy Technology Data Exchange (ETDEWEB)
Bejenari, I; Kantser, V [Institute of Electronic Engineering and Industrial Technologies, Academiei str., 3/3, MD2028 Chisinau (Moldova, Republic of)], E-mail: bejenari@iieti.asm.md
2008-10-03
An asymptotic solution of the Schroedinger equation with non-separable variables is obtained for a particle confined to an infinite elliptic cylinder potential well under an applied uniform longitudinal magnetic field. Using the standard-problem method, dimension-quantized eigenvalues have been calculated when the magnetic length is large enough in comparison with the half of the distance between the boundary ellipse focuses. In semi-classical approximation, the confined electron (hole) states are divided into the boundary states (BS), ring states (RS), hyperbolic caustic states (HCS) and harmonic oscillator states (HOS). For large angular momentum quantum numbers and small radial quantum numbers, the BS and RS are grouped into the 'whispering gallery' mode. They associate with particles moving along the wire cross section boundary. The motion is limited from the wire core by the elliptic caustic. Consisting of the HCS and HOS, the 'jumping ball' modes correspond to the states of particle moving along a wire diameter when the angular momentum quantum number is much less than the radial quantum number. In this case, the motion is restricted by the hyperbolic caustics and two boundary ellipse arcs. For excited hole states in a Bi wire, the energy spectrum and space probability distribution are analyzed.
Energy Technology Data Exchange (ETDEWEB)
Hernandez-Tenorio, C. [Benemerita Universidad Autonoma de Puebla, 7200 Puebla (Mexico) and Universidad Autonoma del Estado de Mexico (Mexico)]. E-mail: celso1@hotmail.com; Belyaeva, T.L. [Universidad Autonoma del Estado de Mexico (Mexico); Serkin, V.N. [Benemerita Universidad Autonoma de Puebla, 7200 Puebla (Mexico)
2007-09-01
The dynamics of nonlinear solitary waves is studied in the framework of the nonlinear Schroedinger equation model with time-dependent harmonic oscillator potential. The model allows one to analyse on general basis a variety of nonlinear phenomena appearing both in Bose-Einstein condensate, condensed matter physics, nonlinear optics, and biophysics. The soliton parametric resonance is investigated by using two complementary methods: the adiabatic perturbation theory and direct numerical experiments. Conditions for reversible and irreversible denaturation of soliton bound states are also considered.
Rodriguez-Toro, Victor A; Velasco-Medina, Jaime
2011-01-01
This paper presents a first approach in order to design an optimal architecture to implement the Numerov method, which solves the time-independent Schroedinger equation (TISE) for one dimension. The design and simulation have been performed by using 64-bits floating-point megafunctions available in Quartus II (Version 9.0). The verification of these results was done by using Matlab. According to these results, it is possible to extend this design to parallel structures, which would be able to calculate several TISE solutions.
Energy Technology Data Exchange (ETDEWEB)
Kravchenko, Vladislav V [Departmento de Telecomunicaciones, SEPI, Escuela Superior de IngenierIa Mecanica y Electrica, Instituto Politecnico Nacional, CP 07738 Mexico DF (Mexico)
2005-01-28
Given a particular solution of a one-dimensional stationary Schroedinger equation this equation of second order can be reduced to a first-order linear ordinary differential equation. This is done with the aid of an auxiliary Riccati differential equation. In the present work we show that the same fact is true in a multidimensional situation also. For simplicity we consider the case of two or three independent variables. One particular solution of the stationary Schroedinger equation allows us to reduce this second-order equation to a linear first-order quaternionic differential equation. As in the one-dimensional case this is done with the aid of an auxiliary quaternionic Riccati equation. The resulting first-order quaternionic equation is equivalent to the static Maxwell system and is closely related to the Dirac equation. In the case of two independent variables it is the well-known Vekua equation from theory of pseudoanalytic (or generalized analytic) functions. Nevertheless, we show that even in this case it is very useful to consider not only complex valued functions, solutions of the Vekua equation, but complete quaternionic functions. In this way the first-order quaternionic equation represents two separate Vekua equations, one of which gives us solutions of the Schroedinger equation and the other one can be considered as an auxiliary equation of a simpler structure. Moreover for the auxiliary equation we always have the corresponding Bers generating pair (F, G), the base of the Bers theory of pseudoanalytic functions, and what is very important, the Bers derivatives of solutions of the auxiliary equation give us solutions of the main Vekua equation and as a consequence of the Schroedinger equation. Based on this fact we obtain an analogue of the Cauchy integral theorem for solutions of the stationary Schroedinger equation. Other results from theory of pseudoanalytic functions can be written for solutions of the Schroedinger equation. Moreover, for an ample
Near the sill of the conformal window: Gauge theories with fermions in two-index representations
Energy Technology Data Exchange (ETDEWEB)
DeGrand, Thomas; Shamir, Yigal; Svetitsky, Benjamin
2013-09-16
We apply Schroedinger functional methods to two gauge theories with fermions in two-index representations: the SU(3) theory with Nf=2 adjoint fermions, and the SU(4) theory with Nf=6 fermions in the two-index antisymmetric representation. Each theory is believed to lie near the bottom of the conformal window for its respective representation. In the SU(3) theory we find a small beta function in strong coupling but we cannot confirm or rule out an infrared fixed point. In the SU(4) theory we find a hint of walking - a beta function that approaches the axis and then turns away from it. In both theories the mass anomalous dimension remains small even at the strongest couplings, much like the theories with fermions in the two-index symmetric representation investigated earlier.
DEFF Research Database (Denmark)
Wulf-Andersen, Trine Østergaard
2012-01-01
be written up and disseminated. The article takes a methodological focus, considering general aims and methods of the research project, before turning to the elaboration on how poetic representations have been constructed and employed as a vehicle for certain kinds of participation, representation......, and dialogue, of situated participants. The article includes a lengthy example of a poetic representation of one participant’s story, and the author comments on the potentials of ‘doing’ poetic representations as an example of writing in ways that challenges what sometimes goes unasked in participative social...
Energy Technology Data Exchange (ETDEWEB)
Dai Chaoqing; Wang Yueyue; Wang Xiaogang, E-mail: dcq424@126.com [School of Sciences, Zhejiang A and F University, Lin' an, Zhejiang 311300 (China)
2011-04-15
By means of the similarity transformation, we obtain exact self-similar solutions (similaritons) of the generalized cubic-quintic (CQ) nonlinear Schroedinger equation with spatially inhomogeneous group velocity dispersion, CQ nonlinearity and amplification or attenuation. Exact balance conditions between the dispersion, nonlinearity and the gain/loss have been obtained. As an example, we investigate their propagation dynamics in the dispersion decreasing fiber (DDF). Considering the fluctuation of the fiber parameter in real application, the exact balance conditions do not satisfy, and so we perform direct numerical analysis with initial 10% white noise for the bright similariton in both the DDF and the periodic distributed amplification system. Numerical calculations indicate stable propagation of the bright similariton over tens of dispersion lengths. These ultrashort self-similar optical waves are potentially useful for all-optical data-processing schemes and the design of beam compressors and amplifiers.
Energy Technology Data Exchange (ETDEWEB)
Romero, MarIa de los Angeles Sandoval; Weder, Ricardo [Instituto de Investigaciones en Matematicas Aplicadas y en Sistemas, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-726, Mexico DF 01000 (Mexico)
2006-09-15
We consider nonlinear Schroedinger equations with a potential, and non-local nonlinearities, that are models in mesoscopic physics, for example of a quantum capacitor, and that are also models of molecular structure. We study in detail the initial value problem for these equations, in particular, existence and uniqueness of local and global solutions, continuous dependence on the initial data and regularity. We allow for a large class of unbounded potentials. We have no restriction on the growth at infinity of the positive part of the potential. We also construct the scattering operator in the case of potentials that go to zero at infinity. Furthermore, we give a method for the unique reconstruction of the potential from the small amplitude limit of the scattering operator. In the case of the quantum capacitor, our method allows us to uniquely reconstruct all the physical parameters from the small amplitude limit of the scattering operator.
Energy Technology Data Exchange (ETDEWEB)
Hoang-Do, Ngoc-Tram; Hoang, Van-Hung; Le, Van-Hoang [Department of Physics, Ho Chi Minh City University of Pedagogy, 280 An Duong Vuong Street, District 5, Ho Chi Minh City (Viet Nam)
2013-05-15
The Feranchuk-Komarov operator method is developed by combining with the Levi-Civita transformation in order to construct analytical solutions of the Schroedinger equation for a two-dimensional exciton in a uniform magnetic field of arbitrary strength. As a result, analytical expressions for the energy of the ground and excited states are obtained with a very high precision of up to four decimal places. Especially, the precision is uniformly stable for the whole range of the magnetic field. This advantage appears due to the consideration of the asymptotic behaviour of the wave-functions in strong magnetic field. The results could be used for various physical analyses and the method used here could also be applied to other atomic systems.
DEFF Research Database (Denmark)
Rasmussen, Majken Kirkegaard; Petersen, Marianne Graves
2011-01-01
Stereotypic presumptions about gender affect the design process, both in relation to how users are understood and how products are designed. As a way to decrease the influence of stereotypic presumptions in design process, we propose not to disregard the aspect of gender in the design process......, as the perspective brings valuable insights on different approaches to technology, but instead to view gender through a value lens. Contributing to this perspective, we have developed Value Representations as a design-oriented instrument for staging a reflective dialogue with users. Value Representations...
Energy Technology Data Exchange (ETDEWEB)
Bessis, D. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1965-03-01
We deal with the scattering of two spinless particles interacting by a superposition of Yukawa potentials. We first obtain an upper bound for the scattering amplitude for simultaneous complex values of energy and angular momentum. We then show that the Regge poles remain confined in small domains of the complex angular momentum plane, we study the variation of these domains when the energy (complex) varies. These first results allow us to deduce an upper bound for the double spectral function, this upper bound is used to rigorously show that the Schroedinger equation implies the Mandelstam representation for the type of potentials we deal with. Finally, the problem of subtractions is entirely solved, showing that the Mellin transform of the double spectral function can be analytically continued into the different simple spectral functions. (author) [French] On traite de la diffusion de deux particules sans spin interagissant par l'intermediaire d'une superposition de potentiels de Yukawa. Nous obtenons tout d'abord une majorante pour l'amplitude de diffusion pour des valeurs simultanement complexes de l'energie et du moment cinetique. On montre alors que les Poles de Regge restent confines dans des domaines restreints du plan complexe du moment cinetique, domaines dont nous etudions la variation pour des valeurs complexes de l'energie. Ces premiers resultats nous permettent alors de deduire une majorante pour la fonction spectrale double, majorante qui est utilisee pour demontrer rigoureusement que l'equation de Schroedinger implique la representation de Mandelstam pour la classe des potentiels envisages. Enfin le probleme des soustractions est entierement resolu, en montrant que la transformee de Mellin de la fonction spectrale double se prolonge analytiquement dans les diverses fonctions spectrales simples. (auteur)
DEFF Research Database (Denmark)
Petersson, Dag; Dahlgren, Anna; Vestberg, Nina Lager
to the enterprises of the medium. This is the subject of Representational Machines: How photography enlists the workings of institutional technologies in search of establishing new iconic and social spaces. Together, the contributions to this edited volume span historical epochs, social environments, technological...
Fock model and Segal-Bargmann transform for minimal representations of Hermitian Lie groups
DEFF Research Database (Denmark)
Hilgert, Joachim; Kobayashi, Toshiyuki; Möllers, Jan
2012-01-01
For any Hermitian Lie group G of tube type we construct a Fock model of its minimal representation. The Fock space is defined on the minimal nilpotent K_C-orbit X in p_C and the L^2-inner product involves a K-Bessel function as density. Here K is a maximal compact subgroup of G, and g_C=k_C+p_C i......For any Hermitian Lie group G of tube type we construct a Fock model of its minimal representation. The Fock space is defined on the minimal nilpotent K_C-orbit X in p_C and the L^2-inner product involves a K-Bessel function as density. Here K is a maximal compact subgroup of G, and g...... intertwines the Schroedinger and Fock model. Its kernel involves the same I-Bessel function. Using the Segal--Bargmann transform we also determine the integral kernel of the unitary inversion operator in the Schroedinger model which is given by a J-Bessel function....
Energy Technology Data Exchange (ETDEWEB)
Tetchou Nganso, Hugues [Universite Catholique de Louvain (Belgium); University of Douala (Cameroon); Popov, Yuri [Moscow State University (Russian Federation); Piraux, Bernard [Universite Catholique de Louvain (Belgium); Madronero, Javier [Technische Universitaet Muenchen (Germany); Kwato Njock, Moise Godfroy [University of Douala (Cameroon)
2011-07-01
We consider the ionization of atomic hydrogen by a strong infrared field. By starting from the corresponding time-dependent Schroedinger equation in momentum space, we develop a model in which the kernel of the non-local Coulomb potential is replaced by a finite sum of separable potentials. Each separable potential supports one bound state of atomic hydrogen. Here, we consider only the 1s, 2s and 2p states. In this way, the full 3-dimensional Schroedinger equation reduces to a system of a few coupled 1-dimensional linear Volterra integral equations. This model is a theoretical tool to understand the actual role of the atomic potential in the intensity regime where tunnel ionization is supposed to take place and where the experimental data for the first ATI peaks are in contradiction with the theoretical predictions based on the strong field approximation model.
DEFF Research Database (Denmark)
Mullins, Michael
to improve design conditions for architects, thereby increasing the “thickness of representation”. The study commences from a broader theoretical enquiry, a review of previous research and examples of relevant context in which virtual reality has been used in practice. It develops from this discussion three......Contemporary communicational and informational processes contribute to the shaping of our physical environment by having a powerful influence on the process of design. Applications of virtual reality (VR) are transforming the way architecture is conceived and produced by introducing dynamic...... elements into the process of design. Through its immersive properties, virtual reality allows access to a spatial experience of a computer model very different to both screen based simulations as well as traditional forms of architectural representation. The dissertation focuses on processes of the current...
Energy Technology Data Exchange (ETDEWEB)
Sakmann, Kaspar
2010-07-21
In this thesis, the physics of trapped, interacting Bose-Einstein condensates is analyzed by solving the many-body Schroedinger equation. Particular emphasis is put on coherence, fragmentation and reduced density matrices. First, the ground state of a trapped Bose-Einstein condensate and its correlation functions are obtained. Then the dynamics of a bosonic Josephson junction is investigated by solving the time-dependent many-body Schroedinger equation numerically exactly. These are the first exact results in literature in this context. It is shown that the standard approximations of the field, Gross-Pitaevskii theory and the Bose-Hubbard model fail at weak interaction strength and within their range of expected validity. For stronger interactions the dynamics becomes strongly correlated and a new equilibration phenomenon is discovered. By comparison with exact results it is shown that a symmetry of the Bose- Hubbard model between attractive and repulsive interactions must be considered an artefact of the model. A conceptual innovation of this thesis are time-dependent Wannier functions. Equations of motion for time-dependent Wannier functions are derived from the variational principle. By comparison with exact results it is shown that lattice models can be greatly improved at little computational cost by letting the Wannier functions of a lattice model become time-dependent. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Briscese, Fabio [Northumbria University, Department of Mathematics, Physics and Electrical Engineering, Newcastle upon Tyne (United Kingdom); Citta Universitaria, Istituto Nazionale di Alta Matematica Francesco Severi, Gruppo Nazionale di Fisica Matematica, Rome (Italy)
2017-09-15
In this paper it is argued how the dynamics of the classical Newtonian N-body system can be described in terms of the Schroedinger-Poisson equations in the large N limit. This result is based on the stochastic quantization introduced by Nelson, and on the Calogero conjecture. According to the Calogero conjecture, the emerging effective Planck constant is computed in terms of the parameters of the N-body system as ℎ ∝ M{sup 5/3}G{sup 1/2}(N/ left angle ρ right angle){sup 1/6}, where is G the gravitational constant, N and M are the number and the mass of the bodies, and left angle ρ right angle is their average density. The relevance of this result in the context of large scale structure formation is discussed. In particular, this finding gives a further argument in support of the validity of the Schroedinger method as numerical double of the N-body simulations of dark matter dynamics at large cosmological scales. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Herbert, John M. [Kansas State Univ., Manhattan, KS (United States). Dept. of Chemistry
1997-01-01
Rayleigh-Schroedinger perturbation theory is an effective and popular tool for describing low-lying vibrational and rotational states of molecules. This method, in conjunction with ab initio techniques for computation of electronic potential energy surfaces, can be used to calculate first-principles molecular vibrational-rotational energies to successive orders of approximation. Because of mathematical complexities, however, such perturbation calculations are rarely extended beyond the second order of approximation, although recent work by Herbert has provided a formula for the nth-order energy correction. This report extends that work and furnishes the remaining theoretical details (including a general formula for the Rayleigh-Schroedinger expansion coefficients) necessary for calculation of energy corrections to arbitrary order. The commercial computer algebra software Mathematica is employed to perform the prohibitively tedious symbolic manipulations necessary for derivation of generalized energy formulae in terms of universal constants, molecular constants, and quantum numbers. As a pedagogical example, a Hamiltonian operator tailored specifically to diatomic molecules is derived, and the perturbation formulae obtained from this Hamiltonian are evaluated for a number of such molecules. This work provides a foundation for future analyses of polyatomic molecules, since it demonstrates that arbitrary-order perturbation theory can successfully be applied with the aid of commercially available computer algebra software.
Representation as the representation of experience
Ankersmit, FR
This essay deals, mainly, with the notion of representation. Representation is associated with texts and, as such, is contrasted to the true singular statement. It is argued that the relationship between the text and what the text represents can never be modeled on the relationship between the true
Representations of Circular Words
Directory of Open Access Journals (Sweden)
László Hegedüs
2014-05-01
Full Text Available In this article we give two different ways of representations of circular words. Representations with tuples are intended as a compact notation, while representations with trees give a way to easily process all conjugates of a word. The latter form can also be used as a graphical representation of periodic properties of finite (in some cases, infinite words. We also define iterative representations which can be seen as an encoding utilizing the flexible properties of circular words. Every word over the two letter alphabet can be constructed starting from ab by applying the fractional power and the cyclic shift operators one after the other, iteratively.
Social representations of women
Directory of Open Access Journals (Sweden)
Álvaro Estramiana, José Luis
2006-05-01
Full Text Available Social Representations is one of the most important theories in contemporary social psychology. Since the social psychologist Serge Moscovici developed his theory of social representations to explain how a scientific theory such as the psychoanalysis turns into a common sense knowledge many studies have been done by different social psychologists. The analysis of the social representations of women as represented in myths and popular beliefs is an excellent opportunity to study how this theory can be applied to this representational field. At the same time it makes possible to understand the formation of attitudes towards women
Ankersmit, F.R.
2010-01-01
This essay focuses on the historical text as a whole. It does so by conceiving of the historical text as representation - in the way the we may say of a photo or a painting that it represents the person depicted on it. It is argued that representation cannot be properly understood by modelling it on
Wigner's Symmetry Representation Theorem
Indian Academy of Sciences (India)
IAS Admin
This article elucidates the important role the no- tion of symmetry has played in physics. It dis- cusses the proof of one of the important theorems of quantum mechanics, viz., Wigner's Symmetry. Representation Theorem. It also shows how the representations of various continuous and dis- crete symmetries follow from the ...
MORPHOLOGICAL REPRESENTATION AND SEMANTIC ...
African Journals Online (AJOL)
MORPHOLOGICAL REPRESENTATION AND SEMANTIC INTERPRETATION. Rudolf P. Botha. Introduction ... The morphological representation assigned to a complex word must provide the formal structure required ..... It has been argued in the literature that "markedness" claims such as. (16)(a) and (b) are unacceptable ...
DEFF Research Database (Denmark)
Willett, Wesley; Jansen, Yvonne; Dragicevic, Pierre
2017-01-01
We introduce embedded data representations, the use of visual and physical representations of data that are deeply integrated with the physical spaces, objects, and entities to which the data refers. Technologies like lightweight wireless displays, mixed reality hardware, and autonomous vehicles...... are making it increasingly easier to display data in-context. While researchers and artists have already begun to create embedded data representations, the benefits, trade-offs, and even the language necessary to describe and compare these approaches remain unexplored. In this paper, we formalize the notion...... of physical data referents – the real-world entities and spaces to which data corresponds – and examine the relationship between referents and the visual and physical representations of their data. We differentiate situated representations, which display data in proximity to data referents, and embedded...
Group and representation theory
Vergados, J D
2017-01-01
This volume goes beyond the understanding of symmetries and exploits them in the study of the behavior of both classical and quantum physical systems. Thus it is important to study the symmetries described by continuous (Lie) groups of transformations. We then discuss how we get operators that form a Lie algebra. Of particular interest to physics is the representation of the elements of the algebra and the group in terms of matrices and, in particular, the irreducible representations. These representations can be identified with physical observables. This leads to the study of the classical Lie algebras, associated with unitary, unimodular, orthogonal and symplectic transformations. We also discuss some special algebras in some detail. The discussion proceeds along the lines of the Cartan-Weyl theory via the root vectors and root diagrams and, in particular, the Dynkin representation of the roots. Thus the representations are expressed in terms of weights, which are generated by the application of the elemen...
Media theory: Representations and examples
National Research Council Canada - National Science Library
Ovchinnikov, Sergei
2008-01-01
In this paper we develop a representational approach to media theory. We construct representations of media by well-graded families of sets and partial cubes and establish the uniqueness of these representations...
Lipparini, Paolo
2017-01-01
We introduce the notion of a nest-representable tolerance and show that some results from our former paper "From congruence identities to tolerance identities" [CT] can be extended to this more general setting.
Hyperfinite representation of distributions
Indian Academy of Sciences (India)
Hyperfinite representation of distributions is studied following the method introduced by Kinoshita [2, 3], although we use a different approach much in the vein of [4]. Products and Fourier transforms of representatives of distributions are also analysed.
Wigner's Symmetry Representation Theorem
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 10. Wigner's Symmetry Representation Theorem: At the Heart of Quantum Field Theory! Aritra Kr Mukhopadhyay. General Article Volume 19 Issue 10 October 2014 pp 900-916 ...
Boundary representation modelling techniques
2006-01-01
Provides the most complete presentation of boundary representation solid modelling yet publishedOffers basic reference information for software developers, application developers and users Includes a historical perspective as well as giving a background for modern research.
Exergy representations in thermodynamics
Favrat, Daniel; Maréchal, François
2015-01-01
The paper reviews various representations of exergy and exergy losses in energy systems going from simple heat exchanger (heat transfer, dissipation and embedded exergy) to the exergy of full energy systems from fossil or non fossil resources (including the diffusion exergy). The systems shown include shell in tube heat exchangers, thermal power cycles, cogeneration, heat pump direct heating systems and cryogenic systems. The representations include simple gravitational analogies to extended ...
Contacts de langues et representations (Language Contacts and Representations).
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…
Questions of Representations in Architecture
DEFF Research Database (Denmark)
2015-01-01
Questions of Representations in Architecture is the first major Danish contribution to the current international discussion on architects' use of representations and the significance of visual media for architecture.......Questions of Representations in Architecture is the first major Danish contribution to the current international discussion on architects' use of representations and the significance of visual media for architecture....
Realizations of the canonical representation
Indian Academy of Sciences (India)
This representation is called the canonical representation. The terminology comes from. Quantum Mechanics where the derived (Lie algebra) representation is known as the 'canon- ical commutation relation'. Traditionally, the canonical representation is realized on the Hilbert space L2(Rn) by the action. (ρ(x, y, z)f )(t) = ze.
Directory of Open Access Journals (Sweden)
Miguel A.V. Ferreira
2007-03-01
Full Text Available In the present work it is exposed synthetically part of an empirical investigation in the field of the sociology of scientific knowledge. From the sociological perspective that assumes the (social activity producing scientific knowledge as one of the epistemological components of this knowledge, it is exposed as, from an autobservational methodology, it has been possible to state the constituently reflexive nature of this activity. A reflexivity in which the formal and formalizeable it is intermingled very indisociably with the existential and informalizable. We present, from these methodologic foundations a (sociological vision of Schroedinger equation that reveals it in its social nataure: beyond its neutral appearance, formal and mathematical, it shows one agencial and active potentiality, shows all the dimensions of an authentic social subject.En el presente trabajo se expone sintéticamente parte de lo que ha sido una investigación empírica en el campo de la sociología del conocimiento científico. Desde la perspectiva sociológica que asume la actividad (social productora de conocimiento científico como uno de los constituyentes epistemológicos de dicho conocimiento, se expone cómo a partir de una metodología autobservacional se ha podido constatar la naturaleza constitutivamente reflexiva de dicha actividad. Una reflexividad en la que lo formal y formalizable se entremezcla indisociablemente con lo informal y vivencial. Presentamos, a partir de estos fundamentos metodológicos, una visión (sociológica de la ecuación de Schroedinger que la revela en su naturaleza social: más allá de su apariencia neutra, formal y matemática, muestra una virtualidad agencial y activa, muestra todas las dimensiones de un auténtico sujeto social. Proponemos, para culminar, que el tipo de reflexividad que entendemos constitutivo de la práctica científica y, por extensión, de cualquier práctica social, se distancia de lo que ha venido defini
Representation Elements of Spatial Thinking
Fiantika, F. R.
2017-04-01
This paper aims to add a reference in revealing spatial thinking. There several definitions of spatial thinking but it is not easy to defining it. We can start to discuss the concept, its basic a forming representation. Initially, the five sense catch the natural phenomenon and forward it to memory for processing. Abstraction plays a role in processing information into a concept. There are two types of representation, namely internal representation and external representation. The internal representation is also known as mental representation; this representation is in the human mind. The external representation may include images, auditory and kinesthetic which can be used to describe, explain and communicate the structure, operation, the function of the object as well as relationships. There are two main elements, representations properties and object relationships. These elements play a role in forming a representation.
Operator representations of frames
DEFF Research Database (Denmark)
Christensen, Ole; Hasannasab, Marzieh
2017-01-01
The purpose of this paper is to consider representations of frames {fk}k∈I in a Hilbert space ℋ of the form {fk}k∈I = {Tkf0}k∈I for a linear operator T; here the index set I is either ℤ or ℒ0. While a representation of this form is available under weak conditions on the frame, the analysis...... of the properties of the operator T requires more work. For example it is a delicate issue to obtain a representation with a bounded operator, and the availability of such a representation not only depends on the frame considered as a set, but also on the chosen indexing. Using results from operator theory we show...... that by embedding the Hilbert space ℋ into a larger Hilbert space, we can always represent a frame via iterations of a bounded operator, composed with the orthogonal projection onto ℋ. The paper closes with a discussion of an open problem concerning representations of Gabor frames via iterations of a bounded...
Introduction to computer data representation
Fenwick, Peter
2014-01-01
Introduction to Computer Data Representation introduces readers to the representation of data within computers. Starting from basic principles of number representation in computers, the book covers the representation of both integer and floating point numbers, and characters or text. It comprehensively explains the main techniques of computer arithmetic and logical manipulation. The book also features chapters covering the less usual topics of basic checksums and 'universal' or variable length representations for integers, with additional coverage of Gray Codes, BCD codes and logarithmic repre
Representation Discovery using Harmonic Analysis
Mahadevan, Sridhar
2008-01-01
Representations are at the heart of artificial intelligence (AI). This book is devoted to the problem of representation discovery: how can an intelligent system construct representations from its experience? Representation discovery re-parameterizes the state space - prior to the application of information retrieval, machine learning, or optimization techniques - facilitating later inference processes by constructing new task-specific bases adapted to the state space geometry. This book presents a general approach to representation discovery using the framework of harmonic analysis, in particu
Mobilities and Representations
DEFF Research Database (Denmark)
Thelle, Mikkel
2017-01-01
, literature, and film. Moreover, we hope the authors of future reviews will reflect on the ways they approached those representations. Such commentaries would provide valuable methodological insights, and we hope to begin that effort with this interview. We have asked four prominent mobility scholars......As the centerpiece of the eighth T2M yearbook, the following interview about representations of mobility signals a new and exciting focus area for Mobility in History. In future issues we hope to include reviews that grapple more with how mobilities have been imagined and represented in the arts...... to consider how they and their peers are currently confronting representations of mobility. This is particularly timely given the growing academic focus on practices, material mediation, and nonrepresentational theories, as well as on bodily reactions, emotions, and feelings that, according to those theories...
Post-representational cartography
Directory of Open Access Journals (Sweden)
Rob Kitchin
2010-03-01
Full Text Available Over the past decade there has been a move amongst critical cartographers to rethink maps from a post-representational perspective – that is, a vantage point that does not privilege representational modes of thinking (wherein maps are assumed to be mirrors of the world and automatically presumes the ontological security of a map as a map, but rather rethinks and destabilises such notions. This new theorisation extends beyond the earlier critiques of Brian Harley (1989 that argued maps were social constructions. For Harley a map still conveyed the truth of a landscape, albeit its message was bound within the ideological frame of its creator. He thus advocated a strategy of identifying the politics of representation within maps in order to circumnavigate them (to reveal the truth lurking underneath, with the ontology of cartographic practice remaining unquestioned.
Directory of Open Access Journals (Sweden)
Roberto De Rubertis
2012-06-01
Full Text Available This article will discuss about the physiological genesis of representation and then it will illustrate the developments, especially in evolutionary perspective, and it will show how these are mainly a result of accidental circumstances, rather than of deliberate intention of improvement. In particular, it will be argue that the representation has behaved like a meme that has arrived to its own progressive evolution coming into symbiosis with the different cultures in which it has spread, and using in this activity human work “unconsciously”. Finally it will be shown how in this action the geometry is an element key, linked to representation both to construct images using graphics operations and to erect buildings using concrete operations.
Understanding representations in design
DEFF Research Database (Denmark)
Bødker, Susanne
1998-01-01
Representing computer applications and their use is an important aspect of design. In various ways, designers need to externalize design proposals and present them to other designers, users, or managers. This article deals with understanding design representations and the work they do in design....... The article is based on a series of theoretical concepts coming out of studies of scientific and other work practices and on practical experiences from design of computer applications. The article presents alternatives to the ideas that design representations are mappings of present or future work situations...
Additive and polynomial representations
Krantz, David H; Suppes, Patrick
1971-01-01
Additive and Polynomial Representations deals with major representation theorems in which the qualitative structure is reflected as some polynomial function of one or more numerical functions defined on the basic entities. Examples are additive expressions of a single measure (such as the probability of disjoint events being the sum of their probabilities), and additive expressions of two measures (such as the logarithm of momentum being the sum of log mass and log velocity terms). The book describes the three basic procedures of fundamental measurement as the mathematical pivot, as the utiliz
Energy Technology Data Exchange (ETDEWEB)
Hoff da Silva, J.M.; Rogerio, R.J.B. [Universidade Estadual Paulista, Departamento de Fisica e Quimica, Guaratingueta, SP (Brazil); Villalobos, C.H.C. [Universidade Estadual Paulista, Departamento de Fisica e Quimica, Guaratingueta, SP (Brazil); Universidade Federal Fluminense, Instituto de Fisica, Niteroi, RJ (Brazil); Rocha, Roldao da [Universidade Federal do ABC-UFABC, Centro de Matematica, Computacao e Cognicao, Santo Andre (Brazil)
2017-07-15
A systematic study of the spinor representation by means of the fermionic physical space is accomplished and implemented. The spinor representation space is shown to be constrained by the Fierz-Pauli-Kofink identities among the spinor bilinear covariants. A robust geometric and topological structure can be manifested from the spinor space, wherein the first and second homotopy groups play prominent roles on the underlying physical properties, associated to fermionic fields. The mapping that changes spinor fields classes is then exemplified, in an Einstein-Dirac system that provides the spacetime generated by a fermion. (orig.)
Compact Information Representations
2016-08-02
detections (e.g., DDoS attacks), machine learning, databases, and search. Fundamentally, compact data representations are highly beneficial because they...engineering problems in data stream computations, real-time network monitoring & anomaly detections (e.g., DDoS attacks), machine learning, databases, and
Hyperfinite representation of distributions
Indian Academy of Sciences (India)
A nonstandard treatment of the theory of distributions in terms of a hyperfinite representa- tion has been presented in papers [2,3] by Kinoshita. A further exploitation of this treatment in an N-dimensional context has been given by Grenier [1]. In the present paper we offer a different approach to the hyperfinite representation, ...
Reflection on Political Representation
DEFF Research Database (Denmark)
Kusche, Isabel
2017-01-01
This article compares how Members of Parliament in the United Kingdom and Ireland reflect on constituency service as an aspect of political representation. It differs from existing research on the constituency role of MPs in two regards. First, it approaches the question from a sociological...
Between Representation and Eternity
DEFF Research Database (Denmark)
Atzbach, Rainer
2016-01-01
. At death, an indi- vidual’s corpse and burial primarily reflect the social act of representation during the funeral. The position of the arms, which have incorrectly been used as a chronological tool in Scandinavia, may indicate an evolution from a more collective act of prayer up to the eleventh century...
DEFF Research Database (Denmark)
Loddegaard, Anne
2009-01-01
out of place in a novel belonging to the serious combat literature of the Catholic Revival, and the direct representation of the supernatural is also surprising because previous Catholic Revival novelists, such as Léon Bloy and Karl-Joris Huysmans, maintain a realistic, non-magical world and deal...
DEFF Research Database (Denmark)
Loddegaard, Anne
2012-01-01
out of place in a novel belonging to the serious combat literature of the Catholic Revival, and the direct representation of the supernatural is also surprising because previous Catholic Revival novelists, such as Léon Bloy and Karl-Joris Huysmans, maintain a realistic, non-magical world and deal...
Moment graphs and representations
DEFF Research Database (Denmark)
Jantzen, Jens Carsten
2012-01-01
Moment graphs and sheaves on moment graphs are basically combinatorial objects that have be used to describe equivariant intersectiion cohomology. In these lectures we are going to show that they can be used to provide a direct link from this cohomology to the representation theory of simple Lie ...
Representation in dynamical agents.
Ward, Ronnie; Ward, Robert
2009-04-01
This paper extends experiments by Beer [Beer, R. D. (1996). Toward the evolution of dynamical neural networks for minimally cognitive behavior. In P. Maes, M. Mataric, J. Meyer, J. Pollack, & S. Wilson (Eds.), From animals to animats 4: Proceedings of the fourth international conference on simulation of adaptive behavior (pp. 421-429). MIT Press; Beer, R. D. (2003). The dynamics of active categorical perception in an evolved model agent (with commentary and response). Adaptive Behavior, 11 (4), 209-243] with an evolved, dynamical agent to further explore the question of representation in cognitive systems. Beer's environmentally-situated visual agent was controlled by a continuous-time recurrent neural network, and evolved to perform a categorical perception task, discriminating circles from diamonds. Despite the agent's high levels of discrimination performance, Beer found no evidence of internal representation in the best-evolved agent's nervous system. Here we examine the generality of this result. We evolved an agent for shape discrimination, and performed extensive behavioral analyses to test for representation. In this case we find that agents developed to discriminate equal-width shapes exhibit what Clark [Clark, A. (1997). The dynamical challenge. Cognitive Science, 21 (4), 461-481] calls "weak-substantive representation". The agent had internal configurations that (1) were understandably related to the object in the environment, and (2) were functionally used in a task relevant way when the target was not visible to the agent.
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…
Sociocognitive Perspectives on Representation.
Jacob, Elin K.; Shaw, Debora
1998-01-01
Discusses research dealing with the cognitive aspects of formal systems of knowledge representation. Highlights include the origins and theoretical foundations of the cognitive viewpoint; cognition and information science; cognitivism, mentalism, and subjective individualism; categorization; mental models; and sociocognitive approaches to indexing…
Women and political representation.
Rathod, P B
1999-01-01
A remarkable progress in women's participation in politics throughout the world was witnessed in the final decade of the 20th century. According to the Inter-Parliamentary Union report, there were only eight countries with no women in their legislatures in 1998. The number of women ministers at the cabinet level worldwide doubled in a decade, and the number of countries without any women ministers dropped from 93 to 48 during 1987-96. However, this progress is far from satisfactory. Political representation of women, minorities, and other social groups is still inadequate. This may be due to a complex combination of socioeconomic, cultural, and institutional factors. The view that women's political participation increases with social and economic development is supported by data from the Nordic countries, where there are higher proportions of women legislators than in less developed countries. While better levels of socioeconomic development, having a women-friendly political culture, and higher literacy are considered favorable factors for women's increased political representation, adopting one of the proportional representation systems (such as a party-list system, a single transferable vote system, or a mixed proportional system with multi-member constituencies) is the single factor most responsible for the higher representation of women.
Images of Galois representations
Anni, Samuele
2013-01-01
In this thesis we investigate $2$-dimensional, continuous, odd, residual Galois representations and their images. This manuscript consists of two parts. In the first part of this thesis we analyse a local\\--global problem for elliptic curves over number fields. Let $E$ be an elliptic curve over a
Realizations of the canonical representation
Indian Academy of Sciences (India)
A characterisation of the maximal abelian subalgebras of the bounded operators on Hilbert space that are normalised by the canonical representation of the Heisenberg group is given. This is used to classify the perfect realizations of the canonical representation.
Minority Representation, Empowerment, and Participation
Banducci, S.A.; Donovan, Todd; Karp, J.A.
2004-01-01
According to the minority empowerment thesis, minority representation strengthens representational links, fosters more positive attitudes toward government, and encourages political participation. We examine this theory from a cross-national perspective, making use of surveys that sampled minorities
Harmonic Analysis and Group Representation
Figa-Talamanca, Alessandro
2011-01-01
This title includes: Lectures - A. Auslander, R. Tolimeri - Nilpotent groups and abelian varieties, M Cowling - Unitary and uniformly bounded representations of some simple Lie groups, M. Duflo - Construction de representations unitaires d'un groupe de Lie, R. Howe - On a notion of rank for unitary representations of the classical groups, V.S. Varadarajan - Eigenfunction expansions of semisimple Lie groups, and R. Zimmer - Ergodic theory, group representations and rigidity; and, Seminars - A. Koranyi - Some applications of Gelfand pairs in classical analysis.
Constructing visual representations
DEFF Research Database (Denmark)
Huron, Samuel; Jansen, Yvonne; Carpendale, Sheelagh
2014-01-01
The accessibility of infovis authoring tools to a wide audience has been identified as a major research challenge. A key task in the authoring process is the development of visual mappings. While the infovis community has long been deeply interested in finding effective visual mappings......, comparatively little attention has been placed on how people construct visual mappings. In this paper, we present the results of a study designed to shed light on how people transform data into visual representations. We asked people to create, update and explain their own information visualizations using only...... tangible building blocks. We learned that all participants, most of whom had little experience in visualization authoring, were readily able to create and talk about their own visualizations. Based on our observations, we discuss participants’ actions during the development of their visual representations...
Deconvolutional Paragraph Representation Learning
Zhang, Yizhe; Shen, Dinghan; Wang, Guoyin; Gan, Zhe; Henao, Ricardo; Carin, Lawrence
2017-01-01
Learning latent representations from long text sequences is an important first step in many natural language processing applications. Recurrent Neural Networks (RNNs) have become a cornerstone for this challenging task. However, the quality of sentences during RNN-based decoding (reconstruction) decreases with the length of the text. We propose a sequence-to-sequence, purely convolutional and deconvolutional autoencoding framework that is free of the above issue, while also being computationa...
Valensbaserad semantisk representation
Lönngren, Lennart
2010-01-01
This is a brief outline of a semantic representation of linguistic objects in Russian—words, phrases, sentences—based on the concept of valency. Valency is explored as a property of all kinds of linguistic signs: words, parts of words, signs with non-phonological expression, and completely implicit signs. An important distinction is made between semantic and syntactic signs, and amongst semantic signs between signs with and without valency (signs denoting "facts" versus signs denoting "things...
1980-03-01
methodology involves the design of programs that exhibit Intelligent behavior, Al researchers have often taken a rather pragmatic approach to the subject...This article has not been about representation formalisms per se, but rather about the pragmatics of epistemology, the study of the nature of knowledge...1977. Levels of complexity In discourse for anaphora disambiguation and speech act interpretation. IJCAI 3, 43-49. Carbonell, J. R. 1970. Al in CAI: An
DEFF Research Database (Denmark)
Jensen, Ole B.
2016-01-01
Dette kapitel gennemgår den såkaldte ”Non-Representational Theory” (NRT), der primært er kendt fra den Angelsaksiske humangeografi, og som særligt er blevet fremført af den engelske geograf Nigel Thrift siden midten af 2000 årtiet. Da positionen ikke kan siges at være specielt homogen vil kapitlet...
The Knowledge Representation Project
1989-07-01
representing k nowledge. I,- ONE was designed to represent the kinds of knowlodge constriicts encountered by developers of natural language processing systems...project called Empirically Valid Knowledge Representation in 1986. One of the first tasks of the new project was to translate NIKL into Common LISP -- a...constraints -- the syntactic structures that appear in LOO% :constraints or implies clauses translate into knowledge structures for which we have
Learning Multisensory Representations
2016-05-23
how the use of these representations influences perceptual judgements and decision making. The program focuses on people’s performances in visual ...organization of visual short-term memory . Psychological Review, 120, 297-328. Yildirim, I. & Jacobs, R. A. (2013). Transfer of object category...in visual short-term memory research. Attention, Perception, & Psychophysics, 76, 2158-2170. Orhan, A. E., Sims, C. R., Jacobs, R. A., & Knill, D. C
Representations of orthogonal polynomials
Koepf, Wolfram; Schmersau, Dieter
1998-01-01
Zeilberger's algorithm provides a method to compute recurrence and differential equations from given hypergeometric series representations, and an adaption of Almquist and Zeilberger computes recurrence and differential equations for hyperexponential integrals. Further versions of this algorithm allow the computation of recurrence and differential equations from Rodrigues type formulas and from generating functions. In particular, these algorithms can be used to compute the differential/diffe...
Translation between representation languages
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.
Pioneers of representation theory
Curtis, Charles W
1999-01-01
The year 1897 was marked by two important mathematical events: the publication of the first paper on representations of finite groups by Ferdinand Georg Frobenius (1849-1917) and the appearance of the first treatise in English on the theory of finite groups by William Burnside (1852-1927). Burnside soon developed his own approach to representations of finite groups. In the next few years, working independently, Frobenius and Burnside explored the new subject and its applications to finite group theory. They were soon joined in this enterprise by Issai Schur (1875-1941) and some years later, by Richard Brauer (1901-1977). These mathematicians' pioneering research is the subject of this book. It presents an account of the early history of representation theory through an analysis of the published work of the principals and others with whom the principals' work was interwoven. Also included are biographical sketches and enough mathematics to enable readers to follow the development of the subject. An introductor...
Hidden Statistics of Schroedinger Equation
Zak, Michail
2011-01-01
Work was carried out in determination of the mathematical origin of randomness in quantum mechanics and creating a hidden statistics of Schr dinger equation; i.e., to expose the transitional stochastic process as a "bridge" to the quantum world. The governing equations of hidden statistics would preserve such properties of quantum physics as superposition, entanglement, and direct-product decomposability while allowing one to measure its state variables using classical methods.
Categorification and higher representation theory
Beliakova, Anna
2017-01-01
The emergent mathematical philosophy of categorification is reshaping our view of modern mathematics by uncovering a hidden layer of structure in mathematics, revealing richer and more robust structures capable of describing more complex phenomena. Categorified representation theory, or higher representation theory, aims to understand a new level of structure present in representation theory. Rather than studying actions of algebras on vector spaces where algebra elements act by linear endomorphisms of the vector space, higher representation theory describes the structure present when algebras act on categories, with algebra elements acting by functors. The new level of structure in higher representation theory arises by studying the natural transformations between functors. This enhanced perspective brings into play a powerful new set of tools that deepens our understanding of traditional representation theory. This volume exhibits some of the current trends in higher representation theory and the diverse te...
Going beyond representational anthropology
DEFF Research Database (Denmark)
Winther, Ida Wentzel
Going beyond representational anthropology: Re-presenting bodily, emotional and virtual practices in everyday life. Separated youngsters and families in Greenland Greenland is a huge island, with a total of four high-schools. Many youngsters (age 16-18) move far away from home in order to get...... transformation work into the young people and their families. In this presentation I want to screen two sequences from the film, in order to show and clarify how mobility and transformation are made and dealt with both from the youngsters’ and their parents’ perspectives, but in asynchronous loups. I want...
Representations of commonsense knowledge
Davis, Ernest
1990-01-01
Representations of Commonsense Knowledge provides a rich language for expressing commonsense knowledge and inference techniques for carrying out commonsense knowledge. This book provides a survey of the research on commonsense knowledge.Organized into 10 chapters, this book begins with an overview of the basic ideas on artificial intelligence commonsense reasoning. This text then examines the structure of logic, which is roughly analogous to that of a programming language. Other chapters describe how rules of universal validity can be applied to facts known with absolute certainty to deduce ot
Individual Representation: A Different Approach to Political Representation
Ruedin, Didier
2012-01-01
This article presents a new conceptualisation and measure of political representation to complement conventional approaches. Individual representation scores place the individual rather than the legislature at the centre, providing a fresh perspective on the relationship between inequality and representation. They are calculated by comparing first the position of the individual with other citizens, and second the position of the individual with the legislature. The article outlines how to mak...
Social Representations of Intelligence
Directory of Open Access Journals (Sweden)
Elena Zubieta
2016-02-01
Full Text Available The article stresses the relationship between Explicit and Implicit theories of Intelligence. Following the line of common sense epistemology and the theory of Social Representations, a study was carried out in order to analyze naive’s explanations about Intelligence Definitions. Based on Mugny & Carugati (1989 research, a self-administered questionnaire was designed and filled in by 286 subjects. Results are congruent with the main hyphotesis postulated: A general overlap between explicit and implicit theories showed up. According to the results Intelligence appears as both, a social attribute related to social adaptation and as a concept defined in relation with contextual variables similar to expert’s current discourses. Nevertheless, conceptions based on “gifted ideology” still are present stressing the main axes of Intelligence debate: biological and sociological determinism. In the same sense, unfamiliarity and social identity are reaffirmed as organizing principles of social representation. The distance with the object -measured as the belief in intelligence differences as a solve/non solve problem- and the level of implication with the topic -teachers/no teachers- appear as discriminating elements at the moment of supporting specific dimensions.
Representation of identities and the politics of representation in cognition
Kanavillil Rajagopalan
2001-01-01
In this paper, I make a plea for viewing representation as first and foremost a political matter. I argue that by so doing we may avoid the many of pitfalls of contemporary theories of cognition as they attempt to tackle the issue of representation. Most of these problems have to do with the fact that representation is treated exclusively as a mimetic or theatrical question. The fact of the matter is however that representation also has a political dimension. Indeed it has always had...
Integral geometry and representation theory
Gel'fand, I M; Vilenkin, N Ya
1966-01-01
Generalized Functions, Volume 5: Integral Geometry and Representation Theory is devoted to the theory of representations, focusing on the group of two-dimensional complex matrices of determinant one.This book emphasizes that the theory of representations is a good example of the use of algebraic and geometric methods in functional analysis, in which transformations are performed not on the points of a space, but on the functions defined on it. The topics discussed include Radon transform on a real affine space, integral transforms in the complex domain, and representations of the group of comp
Intentionality, Representation, and Anticipation
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.
Resource representation in COMPASS
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.
$\\alpha$-Representation for QCD
Tuan, Richard Hong
1998-01-01
An $\\alpha$-parameter representation is derived for gauge field theories.It involves, relative to a scalar field theory, only constants and derivatives with respect to the $\\alpha$-parameters. Simple rules are given to obtain the $\\alpha$-representation for a Feynman graph with an arbitrary number of loops in gauge theories in the Feynman gauge.
Using Integer Manipulatives: Representational Determinism
Bossé, Michael J.; Lynch-Davis, Kathleen; Adu-Gyamfi, Kwaku; Chandler, Kayla
2016-01-01
Teachers and students commonly use various concrete representations during mathematical instruction. These representations can be utilized to help students understand mathematical concepts and processes, increase flexibility of thinking, facilitate problem solving, and reduce anxiety while doing mathematics. Unfortunately, the manner in which some…
Scientific Representation and Science Learning
Matta, Corrado
2014-01-01
In this article I examine three examples of philosophical theories of scientific representation with the aim of assessing which of these is a good candidate for a philosophical theory of scientific representation in science learning. The three candidate theories are Giere's intentional approach, Suárez's inferential approach and Lynch and…
Congruence properties of induced representations
DEFF Research Database (Denmark)
Mayer, Dieter; Momeni, Arash; Venkov, Alexei
In this paper we study representations of the projective modular group induced from the Hecke congruence group of level 4 with Selberg's character. We show that the well known congruence properties of Selberg's character are equivalent to the congruence properties of the induced representations...
Meaningful Representations Prevent Catastrophic Interference
Bieger, J.; Sprinkhuizen-Kuyper, I.G.; Rooij, I.J.E.I. van; Calders, T.; Tuyls, K.; Pechenizkiy, M.
2009-01-01
Artificial Neural Networks (ANNs) attempt to mimic human neural networks in order to perform tasks. In order to do this, tasks need to be represented in ways that the network understands. In ANNs these representations are often arbitrary, whereas in humans it seems that these representations are
University Students' Representations of Study.
Volet, Simone E.; Lawrence, Jeanette A.
1988-01-01
Five women university students' representations of their learning were analyzed and related to their on-going adaptations to course demands. Representations involved their goals, working plans and perceptions of difficulties. Qualitative data from students' accounts were tabulated schematically in relation to Duncker's concepts of productive…
Combinatorial representations of token sequences
Elzinga, C.H.
2005-01-01
This paper presents new representations of token sequences, with and without associated quantities, in Euclidean space. The representations are free of assumptions about the nature of the sequences or the processes that generate them. Algorithms and applications from the domains of structured
Fuzzy Morphological Polynomial Image Representation
Directory of Open Access Journals (Sweden)
Chin-Pan Huang
2010-01-01
Full Text Available A novel signal representation using fuzzy mathematical morphology is developed. We take advantage of the optimum fuzzy fitting and the efficient implementation of morphological operators to extract geometric information from signals. The new representation provides results analogous to those given by the polynomial transform. Geometrical decomposition of a signal is achieved by windowing and applying sequentially fuzzy morphological opening with structuring functions. The resulting representation is made to resemble an orthogonal expansion by constraining the results of opening to equate adapted structuring functions. Properties of the geometric decomposition are considered and used to calculate the adaptation parameters. Our procedure provides an efficient and flexible representation which can be efficiently implemented in parallel. The application of the representation is illustrated in data compression and fractal dimension estimation temporal signals and images.
Multiple representations in physics education
Duit, Reinders; Fischer, Hans E
2017-01-01
This volume is important because despite various external representations, such as analogies, metaphors, and visualizations being commonly used by physics teachers, educators and researchers, the notion of using the pedagogical functions of multiple representations to support teaching and learning is still a gap in physics education. The research presented in the three sections of the book is introduced by descriptions of various psychological theories that are applied in different ways for designing physics teaching and learning in classroom settings. The following chapters of the book illustrate teaching and learning with respect to applying specific physics multiple representations in different levels of the education system and in different physics topics using analogies and models, different modes, and in reasoning and representational competence. When multiple representations are used in physics for teaching, the expectation is that they should be successful. To ensure this is the case, the implementati...
Archival Representation in the Digital Age
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…
Islam and Media Representations
Directory of Open Access Journals (Sweden)
Mohamed Bensalah
2006-04-01
Full Text Available For the author of this article, the media’s treatment of Islam has raised numerous polymorphous questions and debates. Reactivated by the great scares of current events, the issue, though an ancient one, calls many things into question. By way of introduction, the author tries to analyse the complex processes of elaboration and perception of the representations that have prevailed during the past century. In referring to the semantic decoding of the abundant colonial literature and iconography, the author strives to translate the extreme xenophobic tensions and the identity crystallisations associated with the current media orchestration of Islam, both in theWest and the East. He then evokes the excesses of the media that are found at the origin of many amalgams wisely maintained between Islam, Islamism and Islamic terrorism, underscoring their duplicity and their willingness to put themselves, consciously, in service to deceivers and directors of awareness, who are very active at the heart of the politico-media sphere. After levelling a severe accusation against the harmful drifts of the media, especially in times of crisis and war, the author concludes by asserting that these tools of communication, once they are freed of their masks and invective apparatuses, can be re-appropriated by new words and bya true communication between peoples and cultures.
From Local to Global Additive Representation
Wakker, P.P.; Chateauneuf, A.
1993-01-01
This paper studies continuous additive representations of transitive preferences on connected subdomains of product sets. Contrary to what has sometimes been thought, local additive representability does not imply global additive representability. It is shown that the result can nevertheless be
From local to global additive representation
A. Chateauneuf (Alain); P.P. Wakker (Peter)
1993-01-01
textabstractThis paper studies continuous additive representations of transitive preferences on connected subdomains of product sets. Contrary to what has sometimes been thought, local additive representability does not imply global additive representability. It is shown that the result can
Representation of identities and the politics of representation in cognition
Directory of Open Access Journals (Sweden)
Kanavillil Rajagopalan
2001-02-01
Full Text Available
In this paper, I make a plea for viewing representation as first and foremost a political matter. I argue that by so doing we may avoid the many of pitfalls of contemporary theories of cognition as they attempt to tackle the issue of representation. Most of these problems have to do with the fact that representation is treated exclusively as a mimetic or theatrical question. The fact of the matter is however that representation also has a political dimension. Indeed it has always had this political dimension which, counterintuitive though it may seem at first glimpse, manifests itself even in very the attempt to aestheticise the whole issue of representation (as in some versions of postmodernism or to deny its role altogether as a tertium quid between the external world and the cognising mind (as in contemporary neo-pragmatism. I also contend that, by recognising the political nature of representation, we also pave the way for endorsing the thesis that the mind is a social construct, thereby taking some steam out of the thesis of "mind-brain identity" (so-called "identity theory of mind".
(Self)-representations on youtube
DEFF Research Database (Denmark)
Simonsen, Thomas Mosebo
This paper examines forms of self-representation on YouTube with specific focus on Vlogs (Video blogs). The analytical scope of the paper is on how User-generated Content on YouTube initiates a certain kind of audiovisual representation and a particular interpretation of reality that can...... be distinguished within Vlogs. This will be analysed through selected case studies taken from a representative sample of empirically based observations of YouTube videos. The analysis includes a focus on how certain forms of representation can be identified as representations of the self (Turkle 1995, Scannell...... 1996, Walker 2005) and further how these forms must be comprehended within a context of technological constrains, institutional structures and social as well as economical practices on YouTube (Burgess and Green 2009, Van Dijck 2009). It is argued that these different contexts play a vital part...
Number theory via Representation theory
Indian Academy of Sciences (India)
2014-11-09
Number theory via Representation theory. Eknath Ghate. November 9, 2014. Eightieth Annual Meeting, Chennai. Indian Academy of Sciences1. 1. This is a non-technical 20 minute talk intended for a general Academy audience.
Semantic Knowledge Representation (SKR) API
U.S. Department of Health & Human Services — The SKR Project was initiated at NLM in order to develop programs to provide usable semantic representation of biomedical free text by building on resources...
The Fifth Mode of Representation
DEFF Research Database (Denmark)
Hansen, Per Krogh; Behrendt, Poul Olaf
2011-01-01
“The fifth mode of representation: Ambiguous voices in unreliable third person narration”. Sammen med Poul Behrendt. In Per Krogh Hansen, Stefan Iversen, Henrik Skov Nielsen og Rolf Reitan (red.): Strange Voices. Walter de Gruyter, Berlin & New York......“The fifth mode of representation: Ambiguous voices in unreliable third person narration”. Sammen med Poul Behrendt. In Per Krogh Hansen, Stefan Iversen, Henrik Skov Nielsen og Rolf Reitan (red.): Strange Voices. Walter de Gruyter, Berlin & New York...
Paired structures in knowledge representation
DEFF Research Database (Denmark)
Montero, J.; Bustince, H.; Franco de los Ríos, Camilo
2016-01-01
In this position paper we propose a consistent and unifying view to all those basic knowledge representation models that are based on the existence of two somehow opposite fuzzy concepts. A number of these basic models can be found in fuzzy logic and multi-valued logic literature. Here...... of the relationships between several existing knowledge representation formalisms, providing a basis from which more expressive models can be later developed....
Representability of Hom implies flatness
Indian Academy of Sciences (India)
... A basic result of Grothendieck ([EGA], III 7.7.9) says that if F is flat over then hom ( E , F ) is representable for all E . We prove the converse of the above, in fact, we show that if is a relatively ample line bundle on over such that the functor hom ( L − n , F ) is representable for infinitely many positive integers , then F ...
Motion Representation with Acceleration Images
Kataoka, Hirokatsu; He, Yun; Shirakabe, Soma; Satoh, Yutaka
2016-01-01
Information of time differentiation is extremely important cue for a motion representation. We have applied first-order differential velocity from a positional information, moreover we believe that second-order differential acceleration is also a significant feature in a motion representation. However, an acceleration image based on a typical optical flow includes motion noises. We have not employed the acceleration image because the noises are too strong to catch an effective motion feature ...
32 CFR 724.215 - Military representation.
2010-07-01
... 32 National Defense 5 2010-07-01 2010-07-01 false Military representation. 724.215 Section 724.215... BOARD Authority/Policy for Departmental Discharge Review § 724.215 Military representation. Military... consult legal counsel before undertaking such representation. Such representation may be prohibited by 18...
On Behavioral Equivalence of Rational Representations
Trentelman, Harry L.; Willems, JC; Hara, S; Ohta, Y; Fujioka, H
2010-01-01
This article deals with the equivalence of representations of behaviors of linear differential systems In general. the behavior of a given linear differential system has many different representations. In this paper we restrict ourselves to kernel representations and image representations Two kernel
Relativity of representations in quantum mechanics
de la Torre, A C
2001-01-01
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 aX+(1-a)P and (XP+PX)/2 are presented.
Sparse time-frequency representations.
Gardner, Timothy J; Magnasco, Marcelo O
2006-04-18
Auditory neurons preserve exquisite temporal information about sound features, but we do not know how the brain uses this information to process the rapidly changing sounds of the natural world. Simple arguments for effective use of temporal information led us to consider the reassignment class of time-frequency representations as a model of auditory processing. Reassigned time-frequency representations can track isolated simple signals with accuracy unlimited by the time-frequency uncertainty principle, but lack of a general theory has hampered their application to complex sounds. We describe the reassigned representations for white noise and show that even spectrally dense signals produce sparse reassignments: the representation collapses onto a thin set of lines arranged in a froth-like pattern. Preserving phase information allows reconstruction of the original signal. We define a notion of "consensus," based on stability of reassignment to time-scale changes, which produces sharp spectral estimates for a wide class of complex mixed signals. As the only currently known class of time-frequency representations that is always "in focus" this methodology has general utility in signal analysis. It may also help explain the remarkable acuity of auditory perception. Many details of complex sounds that are virtually undetectable in standard sonograms are readily perceptible and visible in reassignment.
An introduction to quiver representations
Derksen, Harm
2017-01-01
This book is an introduction to the representation theory of quivers and finite dimensional algebras. It gives a thorough and modern treatment of the algebraic approach based on Auslander-Reiten theory as well as the approach based on geometric invariant theory. The material in the opening chapters is developed starting slowly with topics such as homological algebra, Morita equivalence, and Gabriel's theorem. Next, the book presents Auslander-Reiten theory, including almost split sequences and the Auslander-Reiten transform, and gives a proof of Kac's generalization of Gabriel's theorem. Once this basic material is established, the book goes on with developing the geometric invariant theory of quiver representations. The book features the exposition of the saturation theorem for semi-invariants of quiver representations and its application to Littlewood-Richardson coefficients. In the final chapters, the book exposes tilting modules, exceptional sequences and a connection to cluster categories. The book is su...
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.
Digital models for architectonical representation
Directory of Open Access Journals (Sweden)
Stefano Brusaporci
2011-12-01
Full Text Available Digital instruments and technologies enrich architectonical representation and communication opportunities. Computer graphics is organized according the two phases of visualization and construction, that is modeling and rendering, structuring dichotomy of software technologies. Visualization modalities give different kinds of representations of the same 3D model and instruments produce a separation between drawing and image’s creation. Reverse modeling can be related to a synthesis process, ‘direct modeling’ follows an analytic procedure. The difference between interactive and not interactive applications is connected to the possibilities offered by informatics instruments, and relates to modeling and rendering. At the same time the word ‘model’ describes different phenomenon (i.e. files: mathematical model of the building and of the scene; raster representation and post-processing model. All these correlated different models constitute the architectonical interpretative model, that is a simulation of reality made by the model for improving the knowledge.
Executive control influences linguistic representations.
Lev-Ari, Shiri; Keysar, Boaz
2014-02-01
Although it is known that words acquire their meanings partly from the contexts in which they are used, we proposed that the way in which words are processed can also influence their representation. We further propose that individual differences in the way that words are processed can consequently lead to individual differences in the way that they are represented. Specifically, we showed that executive control influences linguistic representations by influencing the coactivation of competing and reinforcing terms. Consequently, people with poorer executive control perceive the meanings of homonymous terms as being more similar to one another, and those of polysemous terms as being less similar to one another, than do people with better executive control. We also showed that bilinguals with poorer executive control experience greater cross-linguistic interference than do bilinguals with better executive control. These results have implications for theories of linguistic representation and language organization.
Concepts, ontologies, and knowledge representation
Jakus, Grega; Omerovic, Sanida; Tomažic, Sašo
2013-01-01
Recording knowledge in a common framework that would make it possible to seamlessly share global knowledge remains an important challenge for researchers. This brief examines several ideas about the representation of knowledge addressing this challenge. A widespread general agreement is followed that states uniform knowledge representation should be achievable by using ontologies populated with concepts. A separate chapter is dedicated to each of the three introduced topics, following a uniform outline: definition, organization, and use. This brief is intended for those who want to get to know
Style representation in design grammars
DEFF Research Database (Denmark)
Ahmad, Sumbul; Chase, Scott Curland
2012-01-01
to be transformed according to changing design style needs. Issues of formalizing stylistic change necessitate a lucid and formal definition of style in the design language generated by a grammar. Furthermore, a significant aspect of the definition of style is the representation of aesthetic qualities attributed...... to the style. We focus on grammars for representing and generating styles of design and review the use of grammar transformations for modelling changes in style and design language. We identify a gap in knowledge in the representation of style in grammars and in driving strategic style change using grammar...
Medieval theories of mental representation.
Kemp, S
1998-11-01
Throughout most of the Middle ages, it was generally held that stored mental representations of perceived objects or events preserved the forms or species of such objects. This belief was consistent with a metaphor used by Plato. It was also consistent with the medieval belief that a number of cognitive processes took place in the ventricles of the brain and with the phenomenology of afterimages and imagination itself. In the 14th century, William of Ockham challenged this belief by claiming that mental representations are not stored but instead constructed in the basis of past learned experiences.
The Pitfalls of Visual Representations
Directory of Open Access Journals (Sweden)
Sabrina Bresciani
2015-10-01
Full Text Available A large body of research has addressed the benefits of visualization, whereas the analysis of the pitfalls has not received systematic attention. We aim to provide an overview of the common pitfalls and potential disadvantages of visual representations based on a multidisciplinary literature review. Subsequently, we develop a theoretically grounded classification of common cognitive, emotional, and social risks of visualization and populate it with a comprehensive list of visualization pitfalls. The aim of this research is not to diminish the potential of visualization, but rather to improve visual literacy by structuring our understanding of the possible limitations of graphic representations.
Grobner Basis Representations of Sudoku
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…
Conceptual Knowledge Representation and Reasoning
DEFF Research Database (Denmark)
Oldager, Steen Nikolaj
2003-01-01
One of the main areas in knowledge representation and logic-based artificial intelligence concerns logical formalisms that can be used for representing and reasoning with concepts. For almost 30 years, since research in this area began, the issue of intensionality has had a special status...
Spectral representation of Gaussian semimartingales
DEFF Research Database (Denmark)
Basse-O'Connor, Andreas
2009-01-01
The aim of the present paper is to characterize the spectral representation of Gaussian semimartingales. That is, we provide necessary and sufficient conditions on the kernel K for X t =∫ K t (s) dN s to be a semimartingale. Here, N denotes an independently scattered Gaussian random measure...
Thinking together with material representations
DEFF Research Database (Denmark)
Stege Bjørndahl, Johanne; Fusaroli, Riccardo; Østergaard, Svend
2014-01-01
How do material representations such as models, diagrams and drawings come to shape and aid collective, epistemic processes? This study investigated how groups of participants spontaneously recruited material objects (in this case LEGO blocks) to support collective creative processes in the conte...
Reusable Lexical Representations for Idioms
Odijk, J.E.J.M.
2004-01-01
In this paper I introduce (1) a technically simple and highly theory-independent way for lexically representing flexible idiomatic expressions, and (2) a procedure to incorporate these lexical representations in a wide variety of NLP systems. The method is based on Structural EQuivalence Classes
Educational space representation in cyberspace
Directory of Open Access Journals (Sweden)
Abdurazakov Magomed M.
2016-01-01
Full Text Available The spatial representation problems of the educational sphere, of the information educational milieu, media milieu are analyzed; the problems of the media education, of Smart-education, media competence and media culture of education subjects are examined. The descriptions of the educational cyberspace and interaction characteristics with the educational subjects in the context of modal logic are offered.
Knowledge Representation in Travelling Texts
DEFF Research Database (Denmark)
Mousten, Birthe; Locmele, Gunta
2014-01-01
and the purpose of the text in a new context as well as on predefined parameters for text travel. For texts used in marketing and in technology, the question is whether culture-bound knowledge representation should be domesticated or kept as foreign elements, or should be mirrored or moulded—or should not travel...
Stochastic Representation of Sedimentary Geology
Elmouttie, M. K.; Krähenbühl, G.; Poropat, G. V.; Kelso, I.
2014-03-01
Discrete fracture network representations of discontinuities in rock masses have been shown to be useful in capturing heterogeneity in rock mass properties. Providing computational efficiency in the resulting simulations and analyses is attained, these fracture representations can be combined with structural modelling and sampling algorithms. Multiple fracture network realisations can be generated and the resulting rock mass properties interrogated. Statistical analyses based on fracture connectivity, block size distribution and slope stability can be performed and provide results defined in terms of confidence intervals. For sedimentary geology consisting of dense bedding, equivalent medium continuum methods have traditionally been used in preference to discrete fracture representations due to the large numbers of structures involved and resulting computational complexity. In this paper, it is shown that stochastic representation of these layers can be employed. An analytical solution to accommodate bedding given an assumed block size distribution has been derived. Using this formulation, polyhedral modelling has been used to investigate the influence of bedding on block formation and block size distributions using field data. It is shown that the analysis is both computationally efficient and can capture truncation of size distribution by such layers without numerical methods.
Representation and redistribution in federations.
Dragu, Tiberiu; Rodden, Jonathan
2011-05-24
Many of the world's most populous democracies are political unions composed of states or provinces that are unequally represented in the national legislature. Scattered empirical studies, most of them focusing on the United States, have discovered that overrepresented states appear to receive larger shares of the national budget. Although this relationship is typically attributed to bargaining advantages associated with greater legislative representation, an important threat to empirical identification stems from the fact that the representation scheme was chosen by the provinces. Thus, it is possible that representation and fiscal transfers are both determined by other characteristics of the provinces in a specific country. To obtain an improved estimate of the relationship between representation and redistribution, we collect and analyze provincial-level data from nine federations over several decades, taking advantage of the historical process through which federations formed and expanded. Controlling for a variety of country- and province-level factors and using a variety of estimation techniques, we show that overrepresented provinces in political unions around the world are rather dramatically favored in the distribution of resources.
Discrimination and the aim of proportional representation
DEFF Research Database (Denmark)
Lippert-Rasmussen, Kasper
2008-01-01
Many organizations, companies, and so on are committed to certain representational aims as regards the composition of their workforce. One motivation for such aims is the assumption that numerical underrepresentation of groups manifests discrimination against them. In this article, I articulate...... representational aims in a way that best captures this rationale. My main claim is that the achievement of such representational aims is reducible to the elimination of the effects of wrongful discrimination on individuals and that this very important concern is, in principle, compatible with the representation......, the time-relative account of representational aims expounded shows that, and how, representational aims should accommodate the changing composition of populations over time....
Asymmetrical Representation of Gender in Amharic | Leyew ...
African Journals Online (AJOL)
biased patriarchal grammars. Amharic is one of them. This paper discusses the linguistic and pragmatic representation of gender in Amharic, a gendered language showing masculine and feminine distinction in its grammar. Gender representation ...
Representation learning for cross-modality classification
G. van Tulder (Gijs); M. de Bruijne (Marleen)
2017-01-01
textabstractDifferences in scanning parameters or modalities can complicate image analysis based on supervised classification. This paper presents two representation learning approaches, based on autoencoders, that address this problem by learning representations that are similar across domains.
Democracy and Representation in Paraguay
Directory of Open Access Journals (Sweden)
Liliana Rocío Duarte-Recalde
2017-05-01
Full Text Available This article reviews the electoral accountability dimension as a constitutive mechanism of Paraguayan democracy since 1989, analyzing the factors that limit the representation contained in the administration of the Paraguayan government as a result of the electoral process. We provide an analytic contrast between the democratic principles that guide the Paraguayan electoral institutions and the way their designs are enforced, identifying the gap between formal and informal rules as determinants of political representation. We also describe the barriers that prevent effective access of the population to political participation and competition, the advantages possessed by traditional political parties and interest groups, as well as their implications for democracy. We also review the degree to which elected officials are representative of historically excluded social groups as a result, emphasizing the way women, indigenous and peasant communities have potentially limited power to exercise political influence due to limitations to participation by structural and institutional factors.
Free boundary ballooning mode representation
Zheng, L. J.
2012-10-01
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.
Representation theory of finite monoids
Steinberg, Benjamin
2016-01-01
This first text on the subject provides a comprehensive introduction to the representation theory of finite monoids. Carefully worked examples and exercises provide the bells and whistles for graduate accessibility, bringing a broad range of advanced readers to the forefront of research in the area. Highlights of the text include applications to probability theory, symbolic dynamics, and automata theory. Comfort with module theory, a familiarity with ordinary group representation theory, and the basics of Wedderburn theory, are prerequisites for advanced graduate level study. Researchers in algebra, algebraic combinatorics, automata theory, and probability theory, will find this text enriching with its thorough presentation of applications of the theory to these fields. Prior knowledge of semigroup theory is not expected for the diverse readership that may benefit from this exposition. The approach taken in this book is highly module-theoretic and follows the modern flavor of the theory of finite dimensional ...
Prospective coding in event representation.
Schütz-Bosbach, Simone; Prinz, Wolfgang
2007-06-01
A perceived event such as a visual stimulus in the external world and a to-be-produced event such as an intentional action are subserved by event representations. Event representations do not only contain information about present states but also about past and future states. Here we focus on the role of representing future states in event perception and generation (i.e., prospective coding). Relevant theoretical issues and paradigms are discussed. We suggest that the predictive power of the motor system may be exploited for prospective coding not only in producing but also in perceiving events. Predicting is more advantageous than simply reacting. Perceptual prediction allows us to select appropriate responses ahead of the realization of an (anticipated) event and therefore, it is indispensable to flexibly and timely adapt to new situations and thus, successfully interact with our physical and social environment.
Time representations in social science.
Schulz, Yvan
2012-12-01
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.
SLE and Virasoro Representations: Localization
Dubédat, Julien
2015-06-01
We consider some probabilistic and analytic realizations of Virasoro highest-weight representations. Specifically, we consider measures on paths connecting points marked on the boundary of a (bordered) Riemann surface. These Schramm-Loewner evolution-type measures are constructed by the method of localization in path space. Their partition function (total mass) is the highest-weight vector of a Virasoro representation, and the action is given by Virasoro uniformization. We review the formalism of Virasoro uniformization, which allows to define a canonical action of Virasoro generators on functions (or sections) on a—suitably extended—Teichmüller space. Then we describe the construction of families of measures on paths indexed by marked bordered Riemann surfaces. Finally we relate these two notions by showing that the partition functions of the latter generate a highest-weight representation—the quotient of a reducible Verma module—for the former.
Free boundary ballooning mode representation
Zheng, Linjin
2012-03-01
Considerable efforts have been made in this field to develop a free boundary ballooning mode representation, which can incorporate the peeling mode stability criterion. Those efforts have not succeeded, simply because the so-called ballooning mode invariance is broken toward plasma edge. This makes 1D description of high n modes at plasma edge become impossible, where n is toroidal mode number. Nevertheless, we prove that the existence of ``half" ballooning mode invariance toward plasma core enables an 1.δ-dimentional representation of the modes, where δ˜O(1/n). This considerably reduces the complicity in investigating high n modes at plasma edge and can be used to study peeling-ballooning modes. This technique can also be useful to extend the 1D calculation of fixed boundary ballooning modes for free boundary ballooning modes. Numerical example will also be presented together with the topological symmetry analysis.
Imitation and the Dialectic of Representation.
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…
12 CFR 704.14 - Representation.
2010-01-01
... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Representation. 704.14 Section 704.14 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS CORPORATE CREDIT UNIONS § 704.14 Representation. (a) Board representation. The board will be determined as stipulated in its...
29 CFR 18.34 - Representation.
2010-07-01
... 29 Labor 1 2010-07-01 2010-07-01 true Representation. 18.34 Section 18.34 Labor Office of the... ADMINISTRATIVE LAW JUDGES General § 18.34 Representation. (a) Appearances. Any party shall have the right to... own representation that he or she is in good standing before any of such courts shall be sufficient...
29 CFR 452.127 - Proportionate representation.
2010-07-01
... 29 Labor 2 2010-07-01 2010-07-01 false Proportionate representation. 452.127 Section 452.127 Labor... DISCLOSURE ACT OF 1959 Election Procedures; Rights of Members § 452.127 Proportionate representation. When... delegates who have been chosen by secret ballot, the structure of representation of the membership is a...
75 FR 32273 - Representation Election Procedure
2010-06-08
... 29 CFR Parts 1202 and 1206 RIN 3140-ZA00 Representation Election Procedure AGENCY: National Mediation... delaying the effective date of its rule regarding representation election procedures from June 10, 2010 to... Representation Election Procedure Rule have been made. The NMB will notify participants if there are any further...
7 CFR 917.15 - Representation area.
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... CALIFORNIA Order Regulating Handling Definitions § 917.15 Representation area. Representation area means any...
37 CFR 350.2 - Representation.
2010-07-01
... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Representation. 350.2 Section... ROYALTY JUDGES RULES AND PROCEDURES GENERAL ADMINISTRATIVE PROVISIONS § 350.2 Representation. Individual... representation that the attorney is a member of the bar, in one or more states, in good standing. ...
2010-07-01
... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Representation. 4.9 Section 4.9 Judicial... OF 1974 § 4.9 Representation. The applicant may be represented before the Commission by any person... constitute a representation to the Commission that under the provisions of this part and applicable law he is...
76 FR 36811 - Representation-Case Procedures
2011-06-22
... June 22, 2011 Part IV National Labor Relations Board 29 CFR Parts 101, 102 and 103 Representation--Case... Rules#0;#0; ] NATIONAL LABOR RELATIONS BOARD 29 CFR Parts 101, 102 and 103 RIN 3142-AA08 Representation... the representation of employees for purposes of collective bargaining with their employer. The Board...
Shekgalagari stops and theories of phonological representation ...
African Journals Online (AJOL)
The aim of this paper is to present some aspects of stop consonants, e.g. voice onset time (VOT) and F0 perturbation, and also to present phonological theories of stop representation in order to examine matters of Shekgalagari stop production and phonological representation. Of the phonological representation theories ...
29 CFR 4003.6 - Representation.
2010-07-01
... 29 Labor 9 2010-07-01 2010-07-01 false Representation. 4003.6 Section 4003.6 Labor Regulations... OF AGENCY DECISIONS General Provisions § 4003.6 Representation. A person may file any document or... of attorney, signed by the person making the designation, which authorizes the representation and...
76 FR 80137 - Representation-Case Procedures
2011-12-22
... December 22, 2011 Part IV National Labor Relations Board 29 CFR Parts 101 and 102 Representation--Case... Regulations#0;#0; ] NATIONAL LABOR RELATIONS BOARD 29 CFR Parts 101 and 102 RIN 3142-AA08 Representation--Case... representation of employees for purposes of collective bargaining with their employer. This document explains...
48 CFR 2009.570-4 - Representation.
2010-10-01
... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Representation. 2009.570-4... ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Organizational Conflicts of Interest 2009.570-4 Representation... interest representation provision at 2052.209-71 must be included in solicitations and contracts resulting...
76 FR 72368 - Representation Case Procedures
2011-11-23
...-AAO8 Representation Case Procedures AGENCY: National Labor Relations Board. ACTION: Proposed rule... of petitions relating to the representation of employees for purposes of collective bargaining with... to the Board's rules governing representation-case procedures. A copy of the NPRM may also be...
77 FR 25547 - Representation-Case Procedures
2012-04-30
... April 30, 2012 Part II National Labor Relations Board 29 CFR Parts 101 and 102 Representation--Case... Regulations#0;#0; ] NATIONAL LABOR RELATIONS BOARD 29 CFR Parts 101 and 102 RIN 3142--AA08 Representation... filing and processing of petitions relating to the representation of employees for purposes of collective...
33 CFR 20.301 - Representation.
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Representation. 20.301 Section 20... Motions § 20.301 Representation. (a) A party may appear— (1) Without counsel; (2) With an attorney; or (3... United States. A personal representation of membership is sufficient proof, unless the ALJ orders more...
24 CFR 180.305 - Representation.
2010-04-01
... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Representation. 180.305 Section 180... Representation. (a) HUD is represented by the General Counsel. (b) Any party may appear on his/her/its own behalf... State. The attorney's representation that he/she is in good standing before any of these courts is...
Quadrature representation of finite element variational forms
DEFF Research Database (Denmark)
Ølgaard, Kristian Breum; Wells, Garth N.
2012-01-01
. An alternative to the run-time quadrature approach is the tensor representation presented in Chapter 8. Both the quadrature and tensor approaches are implemented in FFC (see Chapter 11). In this chapter we discuss four strategies for optimizing the quadrature representation for run-time performance...... between the two representations...
27 CFR 71.30 - Personal representation.
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Personal representation. 71.30 Section 71.30 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... General Representation at Hearings § 71.30 Personal representation. Any individual or member of a...
76 FR 37291 - Representation Case Procedures
2011-06-27
... BOARD 29 CFR Parts 101, 102, 103 RIN 3142-AAO8 Representation Case Procedures AGENCY: National Labor... amendments to the Board's rules governing representation case procedures, published at 76 FR 15307 (June 22, 2011) and make other proposals for improving representation case procedures. DATES: The meeting will be...
2010-01-01
... 4 Accounts 1 2010-01-01 2010-01-01 false Representation. 28.25 Section 28.25 Accounts GOVERNMENT... Parties, Practitioners and Witnesses § 28.25 Representation. (a) All parties to a petition may be..., in the petition or responsive pleading. Any subsequent changes in representation shall also be in...
46 CFR 401.615 - Representation.
2010-10-01
... 46 Shipping 8 2010-10-01 2010-10-01 false Representation. 401.615 Section 401.615 Shipping COAST... Representation. (a) The U.S. Registered Pilot, designated “respondent” in a suspension or revocation hearing or... a representation that under the provisions of this subpart and applicable law he is authorized and...
75 FR 26062 - Representation Election Procedure
2010-05-11
... CFR Parts 1202 and 1206 RIN 3140-ZA00 Representation Election Procedure AGENCY: National Mediation... provide that, in representation disputes, a majority of valid ballots cast will determine the craft or.../indicator of employee sentiment in representation disputes and provide employees with clear choices in...
45 CFR 1613.4 - Authorized representation.
2010-10-01
... 45 Public Welfare 4 2010-10-01 2010-10-01 false Authorized representation. 1613.4 Section 1613.4... ON LEGAL ASSISTANCE WITH RESPECT TO CRIMINAL PROCEEDINGS § 1613.4 Authorized representation. Legal... professional responsibility requires representation in a criminal proceeding arising out of a transaction with...
Representation for Reciprocal Agent-Environment Interaction
Bosse, T.; Jonker, C.M.; Treur, J.
2009-01-01
Declarative modelling approaches in principle assume a notion of representation or representational content for the modelling concepts. The notion of representational content as discussed in literature in cognitive science and philosophy of mind shows complications as soon as agent and environment
Aligning computer and human visual representations
Ramakrishnan, K.
2017-01-01
Both computer vision and human visual system target the same goal: to accomplish visual tasks easily via a set of representations. In this thesis, we study to what extent representations from computer vision models align to human visual representations. To study this research question we used an
Temporal Representation in Semantic Graphs
Energy Technology Data Exchange (ETDEWEB)
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.
Active Discriminative Text Representation Learning
Zhang, Ye; Lease, Matthew; Wallace, Byron C.
2016-01-01
We propose a new active learning (AL) method for text classification with convolutional neural networks (CNNs). In AL, one selects the instances to be manually labeled with the aim of maximizing model performance with minimal effort. Neural models capitalize on word embeddings as representations (features), tuning these to the task at hand. We argue that AL strategies for multi-layered neural models should focus on selecting instances that most affect the embedding space (i.e., induce discrim...
Computing Visible-Surface Representations,
1985-03-01
of applications. @ Massachusetts Institute of Technology 1985 "’ki report dcs;crihrs rccarch done at the Arificial lInelligence lhaboratory of the...411FO111 OIMMI bm tpal) IS. SUPPLEMENTARY MOTES None A IS~~~1. KEY WORS (Co~me 01 reerseea ............ MIngUfy ySek It Vision Variational principles...perception of visible surfaces. The explicit representation of visible surfaces, an intermediate goal of computational vision , has since attracted
Experience representation in information systems
Kaczmarek, Jan
2014-01-01
This thesis looks into the ways subjective dimension of experience could be represented in artificial, non-biological systems, in particular information systems. The pivotal assumption is that experience as opposed to mainstream thinking in information science is not equal to knowledge, so that experience is a broader term which encapsulates both knowledge and subjective, affective component of experience, which so far has not been properly embraced by knowledge representation theories. This ...
Experience representation in information systems
Kaczmarek, Jan
2014-01-01
This thesis looks into the ways subjective dimension of experience could be represented in artificial, non-biological systems, in particular information systems. The pivotal assumption is that experience as opposed to mainstream thinking in information science is not equal to knowledge, so that experience is a broader term which encapsulates both knowledge and subjective, affective component of experience, which so far has not been properly embraced by knowledge representation theories. Th...
Reusable Lexical Representations for Idioms
Odijk, J.E.J.M.
2004-01-01
In this paper I introduce (1) a technically simple and highly theory-independent way for lexically representing flexible idiomatic expressions, and (2) a procedure to incorporate these lexical representations in a wide variety of NLP systems. The method is based on Structural EQuivalence Classes for Idioms and therefore called the SEQCI method. I illustrate the approach using the Rosetta MT system as an example of an NLP system. I discuss the advantages and some possible objections to the met...
SAR Image Complex Pixel Representations
Energy Technology Data Exchange (ETDEWEB)
Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
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.
Alternative Approach to Nuclear Data Representation
Energy Technology Data Exchange (ETDEWEB)
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.
Multimedia ontology representation and applications
Chaudhury, Santanu; Ghosh, Hiranmay
2015-01-01
The result of more than 15 years of collective research, Multimedia Ontology: Representation and Applications provides a theoretical foundation for understanding the nature of media data and the principles involved in its interpretation. The book presents a unified approach to recent advances in multimedia and explains how a multimedia ontology can fill the semantic gap between concepts and the media world. It relays real-life examples of implementations in different domains to illustrate how this gap can be filled.The book contains information that helps with building semantic, content-based
Efficient Type Representation in TAL
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.
Representation and Perspective in Science
Directory of Open Access Journals (Sweden)
Bas C. van Fraassen
2007-12-01
Full Text Available The world science describes tends to have a very strange look. We can’t see atoms or force fields, nor are they imaginable within visualizable categories, so neither can we even imagine what the world must be like according to recent physical theories. That tension, between what science depicts as reality and how things appear to us, though it is more striking now, has been with us since modern science began. It can be addressed, and perhaps alleviated by inquiring into how science represents nature. In general, representation is selective, the selection is of what is relevant to the purpose at hand, and success may even require distortion. From this point of view, the constraint on science, that it must ‘save the phenomena’, takes on a new form. The question to be faced is how the perspectival character of the appearances (that is, contents of measurement outcomes can be related to the hidden structure that the sciences postulate. In the competing interpretations of quantum mechanics we can see how certain traditional ideals and constraints are left behind. Specifically, Carlo Rovelli’s Relational Quantum Mechanics offers a probative example of the freedom of scientific representation.
Quiver representations and quiver varieties
Jr, Alexander Kirillov
2016-01-01
This book is an introduction to the theory of quiver representations and quiver varieties, starting with basic definitions and ending with Nakajima's work on quiver varieties and the geometric realization of Kac-Moody Lie algebras. The first part of the book is devoted to the classical theory of quivers of finite type. Here the exposition is mostly self-contained and all important proofs are presented in detail. The second part contains the more recent topics of quiver theory that are related to quivers of infinite type: Coxeter functor, tame and wild quivers, McKay correspondence, and representations of Euclidean quivers. In the third part, topics related to geometric aspects of quiver theory are discussed, such as quiver varieties, Hilbert schemes, and the geometric realization of Kac-Moody algebras. Here some of the more technical proofs are omitted; instead only the statements and some ideas of the proofs are given, and the reader is referred to original papers for details. The exposition in the book requ...
Representation theory a first course
Fulton, William
1991-01-01
The primary goal of these lectures is to introduce a beginner to the finite dimensional representations of Lie groups and Lie algebras. Since this goal is shared by quite a few other books, we should explain in this Preface how our approach differs, although the potential reader can probably see this better by a quick browse through the book. Representation theory is simple to define: it is the study of the ways in which a given group may act on vector spaces. It is almost certainly unique, however, among such clearly delineated subjects, in the breadth of its interest to mathematicians. This is not surprising: group actions are ubiquitous in 20th century mathematics, and where the object on which a group acts is not a vector space, we have learned to replace it by one that is {e. g. , a cohomology group, tangent space, etc. }. As a consequence, many mathematicians other than specialists in the field {or even those who think they might want to be} come in contact with the subject in various ways. It is for ...
Linear free divisors and quiver representations
Buchweitz, Ragnar-Olaf; Mond, David
2005-01-01
Linear free divisors are free divisors, in the sense of K.Saito, with linear presentation matrix (example: normal crossing divisors). Using techniques of deformation theory on representations of quivers, we exhibit families of linear free divisors as discriminants in representation spaces for real Schur roots of a finite quiver. We review some basic material on quiver representations, and explain in detail how to verify whether the discriminant is a free divisor and how to determine its compo...
A Distributed Representation of Remembered Time
2015-11-19
AFRL-AFOSR-VA-TR-2015-0393 A Distributed Representation of Remembered Time Marc Howard TRUSTEES OF BOSTON UNIVERSITY Final Report 11/19/2015...SUBTITLE A Distributed Representation of Remembered Time 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-12-1-0369 5c. PROGRAM ELEMENT NUMBER 61102F 6...the award was to extend a mathematical framework for representing time to also construct scale-invariant representations of space. The extensive
Braid group representation on quantum computation
Energy Technology Data Exchange (ETDEWEB)
Aziz, Ryan Kasyfil, E-mail: kasyfilryan@gmail.com [Department of Computational Sciences, Bandung Institute of Technology (Indonesia); Muchtadi-Alamsyah, Intan, E-mail: ntan@math.itb.ac.id [Algebra Research Group, Bandung Institute of Technology (Indonesia)
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.
Representations of affine Hecke algebras
Xi, Nanhua
1994-01-01
Kazhdan and Lusztig classified the simple modules of an affine Hecke algebra Hq (q E C*) provided that q is not a root of 1 (Invent. Math. 1987). Ginzburg had some very interesting work on affine Hecke algebras. Combining these results simple Hq-modules can be classified provided that the order of q is not too small. These Lecture Notes of N. Xi show that the classification of simple Hq-modules is essentially different from general cases when q is a root of 1 of certain orders. In addition the based rings of affine Weyl groups are shown to be of interest in understanding irreducible representations of affine Hecke algebras. Basic knowledge of abstract algebra is enough to read one third of the book. Some knowledge of K-theory, algebraic group, and Kazhdan-Lusztig cell of Cexeter group is useful for the rest
SLE and Virasoro Representations: Fusion
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.
Sparse Representations of Hyperspectral Images
Swanson, Robin J.
2015-11-23
Hyperspectral image data has long been an important tool for many areas of sci- ence. The addition of spectral data yields significant improvements in areas such as object and image classification, chemical and mineral composition detection, and astronomy. Traditional capture methods for hyperspectral data often require each wavelength to be captured individually, or by sacrificing spatial resolution. Recently there have been significant improvements in snapshot hyperspectral captures using, in particular, compressed sensing methods. As we move to a compressed sensing image formation model the need for strong image priors to shape our reconstruction, as well as sparse basis become more important. Here we compare several several methods for representing hyperspectral images including learned three dimensional dictionaries, sparse convolutional coding, and decomposable nonlocal tensor dictionaries. Addi- tionally, we further explore their parameter space to identify which parameters provide the most faithful and sparse representations.
Minimal Surfaces for Hitchin Representations
DEFF Research Database (Denmark)
Li, Qiongling; Dai, Song
2018-01-01
. In this paper, we investigate the properties of immersed minimal surfaces inside symmetric space associated to a subloci of Hitchin component: $q_n$ and $q_{n-1}$ case. First, we show that the pullback metric of the minimal surface dominates a constant multiple of the hyperbolic metric in the same conformal...... class and has a strong rigidity property. Secondly, we show that the immersed minimal surface is never tangential to any flat inside the symmetric space. As a direct corollary, the pullback metric of the minimal surface is always strictly negatively curved. In the end, we find a fully decoupled system......Given a reductive representation $\\rho: \\pi_1(S)\\rightarrow G$, there exists a $\\rho$-equivariant harmonic map $f$ from the universal cover of a fixed Riemann surface $\\Sigma$ to the symmetric space $G/K$ associated to $G$. If the Hopf differential of $f$ vanishes, the harmonic map is then minimal...
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.
Furman, Wyndol; Collibee, Charlene
2016-12-28
This study examined how representations of parent-child relationships, friendships, and past romantic relationships are related to subsequent romantic representations. Two-hundred 10th graders (100 female; Mage = 15.87 years) from diverse neighborhoods in a Western U.S. city were administered questionnaires and were interviewed to assess avoidant and anxious representations of their relationships with parents, friends, and romantic partners. Participants then completed similar questionnaires and interviews about their romantic representations six more times over the next 7.5 years. Growth curve analyses revealed that representations of relationships with parents, friends, and romantic partners each uniquely predicted subsequent romantic representations across development. Consistent with attachment and behavioral systems theory, representations of romantic relationships are revised by representations and experiences in other relationships. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.
On representation and weighted utilitarian representation of preference orders on finite streams
Mitra, Tapan; Ozbek, Mahmut Kemal
2010-01-01
In this paper we re-examine the axiomatic basis of the key result on weighted utilitarian representation of preference orders on finite utility streams. We show that a preference order satisfying the axioms of Minimal Individual Symmetry, Invariance and Strong Pareto need not have a representation, and thus in particular a weighted utilitarian representation. The example establishing this result might also be of interest for the literature on the representation of preference orders. We then e...
The Nine Lives of Schroedinger's Cat
Schreiber, Zvi
1995-01-01
This MSc dissertation surveys nine interpretations of non-relativistic quantum mechanics. Extensive references are given. The interpretations covered are: the orthodox interpretation, Bohr's interpretation, the idea that the mind causes collapse, hidden variables, the many-worlds interpretation, the many-minds interpretation, Bohm's interpretation and two interpretations based on decoherent histories.
Quantum measurements without Schroedinger cat states
Energy Technology Data Exchange (ETDEWEB)
Spehner, D [Institut Fourier, 100 rue des Maths, 38402 Saint-Martin d' Heres (France); Haake, F [Fachbereich Physik, Universitaet Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg (Germany)
2007-10-15
We report and give an alternative derivation of some results on a model for a quantum measurement studied in [1]. The measured microscopic system is coupled to the position of a macroscopic pointer, which itself interacts with its environment via its momentum. The entanglement between the system and the pointer produced by their mutual interaction is simultaneous with the decoherence of distinct pointer readings resulting from leakage of information to the environment. After a discussion on the various time scales in the model we calculate the matrix elements of the system-pointer density operator between eigenstates of the measured observable with distinct eigenvalues. In general, the decay with time of these coherences is neither exponential nor gaussian. We determine the decoherence (decay) time in terms of the strength of the system-pointer and pointer-environment couplings. This decoherence time does not depend upon the details of the pointer-bath coupling as soon as it is smaller than the bath correlation time (non-Markov regime). In contrast, in the Markov regime it depends strongly on whether this coupling is Ohmic or super-Ohmic.
Derivation of an applied nonlinear Schroedinger equation
Energy Technology Data Exchange (ETDEWEB)
Pitts, Todd Alan [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Laine, Mark Richard [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Schwarz, Jens [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Rambo, Patrick K. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Karelitz, David B. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
2015-01-01
We derive from first principles a mathematical physics model useful for understanding nonlinear optical propagation (including filamentation). All assumptions necessary for the development are clearly explained. We include the Kerr effect, Raman scattering, and ionization (as well as linear and nonlinear shock, diffraction and dispersion). We explain the phenomenological sub-models and each assumption required to arrive at a complete and consistent theoretical description. The development includes the relationship between shock and ionization and demonstrates why inclusion of Drude model impedance effects alters the nature of the shock operator. Unclassified Unlimited Release
Solving Schroedinger's equation using random walks
Aspuru-Guzik, Alan
Exact and almost exact solutions for energies and properties of atoms and molecules can be obtained by quantum Monte Carlo (QMC) methods. This thesis is composed of different contributions to various QMC methodologies, as well as applications to electronic excitations of biological systems. We propose a wave function optimization functional that is robust regarding the presence of outliers. Our work, and subsequent applications by others, has shown the convergence properties and robustness of the absolute deviation (AD) functional as compared to the variance functional (VF). We apply the method to atoms from the second row of the periodic table, as well as third-row transition metal atoms, including an all-electron calculation of Sc. In all cases, the AD functional converges faster than the VF. Soft effective core potentials (ECPs) with no divergence at the origin are constructed and validated for second- an third-row atoms of the periodic table. The ECPs we developed have been used by others in several successful studies. As an application of the DMC approach to biochemical problems, we studied the electronic excitations of free-base porphyrin and obtained results in excellent agreement with experiment. These findings validate the use of the DMC approach for these kinds of systems. A study of the role of spheroidene in the photo-protection mechanism of Rhodobacter sphaeroides is described. At the time of writing, calculations for the estimation of excitation energies for the bacteriochlorophyll and spheroidene molecules as well as storage of the random walkers for future prediction of the excitation energy transfer rate are being performed. To date, the calculations mentioned above are the largest all-electron studies on molecules. For the computation of these systems, a sparse linear-scaling DMC algorithm was developed. This algorithm provides a speedup of at least a factor of ten over previously published methods. The method is validated on systems up to 390 electrons. A summary of the Fermion Monte Carlo (FMC) algorithm as well as an application to the Be atom are discussed. The Zori package, a linear-scaling massively-parallel open-source program that uses modern programming libraries, was developed. The program is made available to the public under the GNU/General Public License (GPL). The capabilities of the Zori program are summarized.
Switching between Representations in Reinforcement Learning
Seijen, H. van; Whiteson, S.; Kester, L.
2010-01-01
This chapter presents and evaluates an online representation selection method for factored Markov decision processes (MDPs). The method addresses a special case of the feature selection problem that only considers certain subsets of features, which we call candidate representations. A motivation for
Student Teachers' Knowledge about Chemical Representations
Taskin, Vahide; Bernholt, Sascha; Parchmann, Ilka
2017-01-01
Chemical representations serve as a communication tool not only in exchanges between scientists but also in chemistry lessons. The goals of the present study were to measure the extent of student teachers' knowledge about chemical representations, focusing on chemical formulae and structures in particular, and to explore which factors related to…
Binary Representations of Fingerprint Spectral Minutiae Features
Xu, H.; Veldhuis, Raymond N.J.
A fixed-length binary representation of a fingerprint has the advantages of a fast operation and a small template storage. For many biometric template protection schemes, a binary string is also required as input. The spectral minutiae representation is a method to represent a minutiae set as a
15 CFR 766.4 - Representation.
2010-01-01
... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Representation. 766.4 Section 766.4 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF... PROCEEDINGS § 766.4 Representation. A respondent individual may appear and participate in person, a...
15 CFR 785.5 - Representation.
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... Representation. An individual respondent may appear, in person, or be represented by a duly authorized officer or...
28 CFR 51.58 - Representation.
2010-07-01
... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Representation. 51.58 Section 51.58 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) PROCEDURES FOR THE ADMINISTRATION OF SECTION 5 OF... Representation. (a) Introduction. This section and the sections that follow set forth factors—in addition to...
Klein Topological Field Theories from Group Representations
Directory of Open Access Journals (Sweden)
Sergey A. Loktev
2011-07-01
Full Text Available We show that any complex (respectively real representation of finite group naturally generates a open-closed (respectively Klein topological field theory over complex numbers. We relate the 1-point correlator for the projective plane in this theory with the Frobenius-Schur indicator on the representation. We relate any complex simple Klein TFT to a real division ring.
33 CFR 327.7 - Representation.
2010-07-01
... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Representation. 327.7 Section 327.7 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE PUBLIC HEARINGS § 327.7 Representation. At the public hearing, any person may appear on his own behalf...
20 CFR 901.42 - Representation.
2010-04-01
... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Representation. 901.42 Section 901.42 Employees' Benefits JOINT BOARD FOR THE ENROLLMENT OF ACTUARIES REGULATIONS GOVERNING THE PERFORMANCE OF... Enrollment § 901.42 Representation. A respondent or proposed respondent may appear at conference or hearing...
2010-07-01
... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Representation. 8.61 Section 8.61 Money and Finance: Treasury Office of the Secretary of the Treasury PRACTICE BEFORE THE BUREAU OF ALCOHOL, TOBACCO AND FIREARMS Disciplinary Proceedings § 8.61 Representation. A respondent or proposed...
10 CFR 710.34 - Attorney representation.
2010-01-01
... 10 Energy 4 2010-01-01 2010-01-01 false Attorney representation. 710.34 Section 710.34 Energy DEPARTMENT OF ENERGY CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO CLASSIFIED MATTER OR... Classified Matter or Special Nuclear Material Miscellaneous § 710.34 Attorney representation. In the event...
31 CFR 15.737-18 - Representation.
2010-07-01
... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Representation. 15.737-18 Section 15.737-18 Money and Finance: Treasury Office of the Secretary of the Treasury POST EMPLOYMENT CONFLICT OF INTEREST Administrative Enforcement Proceedings § 15.737-18 Representation. A respondent or proposed...
15 CFR 719.7 - Representation.
2010-01-01
... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Representation. 719.7 Section 719.7 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF... Representation. A respondent individual may appear and participate in person, a corporation by a duly authorized...
7 CFR 981.31 - Membership representation.
2010-01-01
... 7 Agriculture 8 2010-01-01 2010-01-01 false Membership representation. 981.31 Section 981.31 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... Regulating Handling Almond Board of California § 981.31 Membership representation. Membership of the Board...
29 CFR 1202.3 - Representation disputes.
2010-07-01
... 29 Labor 4 2010-07-01 2010-07-01 false Representation disputes. 1202.3 Section 1202.3 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD RULES OF PROCEDURE § 1202.3 Representation disputes. If any dispute shall arise among a carrier's employees as to who are the representatives of such...
43 CFR 4.1606 - Department representation.
2010-10-01
... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Department representation. 4.1606 Section 4.1606 Public Lands: Interior Office of the Secretary of the Interior DEPARTMENT HEARINGS AND...-76 § 4.1606 Department representation. (a) Upon receipt of the docketing notice, the Solicitor shall...
22 CFR 18.13 - Representation.
2010-04-01
... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Representation. 18.13 Section 18.13 Foreign Relations DEPARTMENT OF STATE PERSONNEL REGULATIONS CONCERNING POST EMPLOYMENT CONFLICT OF INTEREST Administrative Enforcement Proceedings § 18.13 Representation. A respondent or proposed respondent may appear in...
15 CFR 280.205 - Representation.
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... QUALITY Enforcement § 280.205 Representation. A respondent individual may appear and participate in person...
15 CFR 90.18 - Representation.
2010-01-01
... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Representation. 90.18 Section 90.18 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS... Representation. A challenging unit of government may be represented by its chief executive officer or by counsel...
18 CFR 1308.22 - Representation.
2010-04-01
... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Representation. 1308.22 Section 1308.22 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY CONTRACT DISPUTES Board of Contract Appeals § 1308.22 Representation. (a) In any appeal to the Board, a Contractor may be...
Stochastic integral representations of quantum martingales on ...
Indian Academy of Sciences (India)
Introduction. The stochastic integral representations of quantum martingales have been studied by many authors (see [2,6,7,10,11,14,15,18,19], etc). In [18], Parthasarathy and Sinha established a stochastic integral representation of a regular bounded quantum martingale on Fock space with respect to the basic ...
10 CFR 60.65 - Representation.
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 under...
2010-07-01
... 34 Education 1 2010-07-01 2010-07-01 false Representation. 81.8 Section 81.8 Education Office of the Secretary, Department of Education GENERAL EDUCATION PROVISIONS ACT-ENFORCEMENT General Provisions § 81.8 Representation. A party to, or other participant in, a case may be represented by counsel...
45 CFR 1225.5 - Representation.
2010-10-01
... 45 Public Welfare 4 2010-10-01 2010-10-01 false Representation. 1225.5 Section 1225.5 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE VOLUNTEER DISCRIMINATION COMPLAINT PROCEDURE General Provisions § 1225.5 Representation. Any aggrieved party...
10 CFR 63.65 - Representation.
2010-01-01
... 10 Energy 2 2010-01-01 2010-01-01 false Representation. 63.65 Section 63.65 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN A GEOLOGIC REPOSITORY AT YUCCA... Tribes § 63.65 Representation. Any person who acts under this subpart as a representative for the State...
8 CFR 1003.16 - Representation.
2010-01-01
... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Representation. 1003.16 Section 1003.16 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE GENERAL PROVISIONS EXECUTIVE OFFICE FOR IMMIGRATION REVIEW Immigration Court-Rules of Procedure § 1003.16 Representation. (a...
42 CFR 412.280 - Representation.
2010-10-01
... 42 Public Health 2 2010-10-01 2010-10-01 false Representation. 412.280 Section 412.280 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM... Board Composition and Procedures § 412.280 Representation. (a) General. A party may be represented by...
10 CFR 10.37 - Attorney representation.
2010-01-01
... 10 Energy 1 2010-01-01 2010-01-01 false Attorney representation. 10.37 Section 10.37 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED... representation. In the event the individual is represented by an attorney or other representative, the individual...
10 CFR 72.206 - Representation.
2010-01-01
... 10 Energy 2 2010-01-01 2010-01-01 false Representation. 72.206 Section 72.206 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL... Information to State Governments and Indian Tribes § 72.206 Representation. Any person who acts under this...
Improving Representational Competence with Concrete Models
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…
Transqueer Representations and How We Educate
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…
Visual representations in cognition: It's about time
van Zoest, W.; Hunt, A.; Kingstone, A.
2010-01-01
Visual cognition relies on changing representations of visual information. The dynamic nature of representations is demonstrated by new findings in human perception and attention showing that the influence of specific aspects of a stimulus on behavior changes dramatically over time. As a
ON REGRESSION REPRESENTATIONS OF STOCHASTIC-PROCESSES
RUSCHENDORF, L; DEVALK, [No Value
We construct a.s. nonlinear regression representations of general stochastic processes (X(n))n is-an-element-of N. As a consequence we obtain in particular special regression representations of Markov chains and of certain m-dependent sequences. For m-dependent sequences we obtain a constructive
Body-Specific Representations of Spatial Location
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…
An Axiomatic Representation of System Dynamics
Baianu, I
2004-01-01
An axiomatic representation of system dynamics is introduced in terms of categories, functors, organismal supercategories, limits and colimits of diagrams. Specific examples are considered in Complex Systems Biology, such as ribosome biogenesis and Hormonal Control in human subjects. "Fuzzy" Relational Structures are also proposed for flexible representations of biological system dynamics and organization.
Bridge: Intelligent Tutoring with Intermediate Representations
1988-05-01
Research and Development Center and Psychology Department University of Pittsburgh Pittsburgh, PA. 15260 The Artificial Intelligence and Psychology...problem never introduces more than one unfamiliar plan. Inteligent Tutoring With Intermediate Representations - Bonar and Cunniigbam 4 You must have a... Inteligent Tutoring With ntermediate Representations - Bonar and Cunningham 7 The requirements are specified at four differcnt levels, corresponding to
Dynamic representations on the interactive whiteboard
van der Meij, Hans; van der Meij, Jan; de Vries, Erica; Scheiter, Katharina
2012-01-01
In this study we assessed whether presenting dynamic representations on an IWB would lead to better learning gains compared to presenting static representations. Participants were 7-8 year old primary school children learning about views (N = 151) and the water cycle (N = 182). The results showed
Connectivity in the regular polytope representation
Thompson, R.J.; Van Oosterom, P.J.M.
2009-01-01
In order to be able to draw inferences about real world phenomena from a representation expressed in a digital computer, it is essential that the representation should have a rigorously correct algebraic structure. It is also desirable that the underlying algebra be familiar, and provide a close
Constitutionalising the Right Legal Representation at CCMA ...
African Journals Online (AJOL)
Recently, the issue of legal representation at internal disciplinary hearings and CCMA arbitrations has been a fervent topic of labour law discourse in South Africa. While the courts have consistently accepted the common law principle that there is no absolute right to legal representation at tribunals other than courts of law, ...
An introduction to quasigroups and their representations
Smith, Jonathan D H
2006-01-01
Collecting results scattered throughout the literature into one source, An Introduction to Quasigroups and Their Representations shows how representation theories for groups are capable of extending to general quasigroups and illustrates the added depth and richness that result from this extension.To fully understand representation theory, the first three chapters provide a foundation in the theory of quasigroups and loops, covering special classes, the combinatorial multiplication group, universal stabilizers, and quasigroup analogues of abelian groups. Subsequent chapters deal with the three main branches of representation theory-permutation representations of quasigroups, combinatorial character theory, and quasigroup module theory. Each chapter includes exercises and examples to demonstrate how the theories discussed relate to practical applications. The book concludes with appendices that summarize some essential topics from category theory, universal algebra, and coalgebras.Long overshadowed by general ...
When data representation compromise data security
DEFF Research Database (Denmark)
Simonsen, Eivind Ortind; Dahl, Mads Ronald
. These representations can be used for multiple purposes such as publications in journals, teaching and conference material. But when created, stored and distributed in a digital form there is a risk of compromising data security. Data beyond the once used specifically to create the representation can be included......WHEN DATA REPRESENTATION COMPROMISE DATA SECURITY The workflow of transforming data into informative representations makes extensive usage of computers and software. Scientists have a conventional tradition for producing publications that include tables and graphs as data representations...... as Object Linking and Embedding (OLE-objects). The OLE-object may “hide” data, in some cases sensitive data, such as data from research or health care information that was in the original data complex. This issue is known and documented but why is it then still a problem leading to data being exposed...
ABJM Wilson loops in arbitrary representations
Energy Technology Data Exchange (ETDEWEB)
Hatsuda, Yasuyuki [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Tokyo Institute of Technology (Japan). Dept. of Physics; Honda, Masazumi [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst. and Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics
2013-06-15
We study vacuum expectation values (VEVs) of circular half BPS Wilson loops in arbitrary representations in ABJM theory. We find that those in hook representations are reduced to elementary integrations thanks to the Fermi gas formalism, which are accessible from the numerical studies similar to the partition function in the previous studies. For non-hook representations, we show that the VEVs in the grand canonical formalism can be exactly expressed as determinants of those in the hook representations. Using these facts, we can study the instanton effects of the VEVs in various representations. Our results are consistent with the worldsheet instanton effects studied from the topological string and a prescription to include the membrane instanton effects by shifting the chemical potential, which has been successful for the partition function.
Operator representation for effective realistic interactions
Energy Technology Data Exchange (ETDEWEB)
Weber, Dennis; Feldmeier, Hans; Neff, Thomas [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)
2013-07-01
We present a method to derive an operator representation from the partial wave matrix elements of effective realistic nucleon-nucleon potentials. This method allows to employ modern effective interactions, which are mostly given in matrix element representation, also in nuclear many-body methods requiring explicitly the operator representation, for example ''Fermionic Molecular Dynamics'' (FMD). We present results for the operator representation of effective interactions obtained from the Argonne V18 potential with the Uenitary Correlation Operator Method'' (UCOM) and the ''Similarity Renormalization Group'' (SRG). Moreover, the operator representation allows a better insight in the nonlocal structure of the potential: While the UCOM transformed potential only shows a quadratic momentum dependence, the momentum dependence of SRG transformed potentials is beyond such a simple polynomial form.
Locally analytic vectors in representations of locally
Emerton, Matthew J
2017-01-01
The goal of this memoir is to provide the foundations for the locally analytic representation theory that is required in three of the author's other papers on this topic. In the course of writing those papers the author found it useful to adopt a particular point of view on locally analytic representation theory: namely, regarding a locally analytic representation as being the inductive limit of its subspaces of analytic vectors (of various "radii of analyticity"). The author uses the analysis of these subspaces as one of the basic tools in his study of such representations. Thus in this memoir he presents a development of locally analytic representation theory built around this point of view. The author has made a deliberate effort to keep the exposition reasonably self-contained and hopes that this will be of some benefit to the reader.
Small representations of quantum affine algebras
Chari, Vyjayanthi; Pressley, Andrew
1994-02-01
We characterize the finite-dimensional representations of the quantum affine algebra U q (widehat{sl} n+1) (where q ∈ ℂ× is not a root of unity) which are irreducible as representations of U q (sl n+1). We call such representations ‘small’. In 1986, Jimbo defined a family of homomorphisms ev a from U q (sl n+1) to (an enlargement of) U q (sl, n+1), depending on a parameter a ∈ ℂ·. A second family, ev a can be obtained by a small modification of Jimbo's formulas. We show that every small representation of U q (widehat{sl} n+1) is obtained by pulling back an irreducible representation of U q (sl n+1) by ev a or ev a for some a ∈ ℂ·.
Primary Teachers' Representational Practices: From Competency to Fluency
Nichols, Kim; Stevenson, Michael; Hedberg, John; Gillies, Robyn Margaret
2016-01-01
Eighteen primary teachers across three conditions (Representational Fluency, Representational Agency, Comparison) received two days of training around an inquiry unit on plate tectonics replete with representations. The Representational Agency group also received training around the semiotic and material affordances of representations while the…
Mental Representations in Art Discourse
Directory of Open Access Journals (Sweden)
Katja Sudec
2014-03-01
Full Text Available The paper starts by examining the content included in the museum environment, where I write about the type of relations that emerge in a museum or artistic setting. This is followed by an observation of a social act (socialising and a chapter on the use of food in an artistic venue. At the end, I address art education via the format that I developed at the 6th Berlin Biennale. This is followed by an overview of the cognitive model of the fort-da game based on Freud’s theory via two discourse models. Here, I address discourse on art works in the form of a lecture or reading, where the art space is fictitiously present, and then move on to discuss discourse on art works in real, “present” art space. This is followed by a section on actions (Handlungen in German and methods supporting the fort-da model. The last part of the article examines the issue of “mental representations”, defining and explaining the function of mental representations with regard to the target audience of the blind and visually impaired.
Continuum representations of cellular solids
Energy Technology Data Exchange (ETDEWEB)
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.
Image-based BRDF Representation
Directory of Open Access Journals (Sweden)
Mihálik A.
2015-12-01
Full Text Available To acquire a certain level of photorealism in computer graphics, it is necessary to analyze, how the materials scatter the incident light. In this work, we propose the method to direct rendering of isotropic bidirectional reflectance function (BRDF from the small set of images. The image-based rendering is focused to synthesize as accurately as possible scenes composed of natural and artificial objects. The realistic image synthesis of BRDF data requires evaluation of radiance over the multiple directions of incident and scattered light from the surface. In our approach the images depict only the material reflectance, the shape is represented as the object geometry. We store the BRDF representation, acquired from the sample material, in a number of two-dimensional textures that contain images of spheres lit from the multiple directions. In order to render particular material, we interpolate between textures in the similar way the image morphing works. Our method allows the real-time rendering of tabulated BRDF data on low memory devices such as mobile phones.
Scientific Representation and Nominalism: An Empiricist View
Directory of Open Access Journals (Sweden)
Otávio Bueno
2008-12-01
Full Text Available Can a constructive empiricist make sense of scientific representation? Usually, a scientific model is an abstract entity (e.g., formulated in set theory, and scientific representation is conceptualized as an intentional relation between scientific models and certain aspects of the world. On this conception, since both the models and the representation relation are abstract, a constructive empiricist, who is not committed to the existence of abstract entities, would be unable to invoke these notions to make sense of scientific representation. In this paper, instead of understanding representation as a relation between abstract entities, I focus on the activity of representing, and argue that it provides a way of making sense of representation within the boundaries of empiricism. The activity of representing doesn’t deal with abstract entities, but with concrete ones, such as inscriptions, templates, and blueprints. In the end, by examining the practice of representing, rather than an artificially reified product—the representation—the constructive empiricist has the resources to make sense of scientific representation in empiricist terms.
General regression and representation model for classification.
Directory of Open Access Journals (Sweden)
Jianjun Qian
Full Text Available 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.
IMAGES AND SOCIAL REPRESENTATION: SEMIOTIC ANALYSIS CONTRIBUTIONS
Directory of Open Access Journals (Sweden)
Izabela Gonçalves Terra
2016-09-01
Full Text Available The common sense knowledge formation is object of study of the Social Representation Theory, which highlights the role of communication in the production of comprehension by the subjects. The visual images favor the socialization of meanings and are active elements in the formation of social representations. Given the expressive role of the images in the formation of representational contents, this paper aims to present a semiotics analysis method for researches on social representations. The semiotic analysis of images was selected as a theoretical and methodological basis, for offering the means required for guidance for an effective research method to identify the social representations of socially shared iconic signs. The analysis method was explored by means of analytical procedures, employed for the apprehension of social representations of the feminine in posters for Brazilian Ministry of Health campaigns, which allowed access to the network of meanings associated with the analyzed visual image. It should be emphasized that the relevance of the use of semiotic analysis to analyze social representations, which presents itself as a fertile perspective for further studies expanding the possibilities of exploitation of visual content.
77 FR 13329 - Information Collection; Small Business Size Representation
2012-03-06
...; Small Business Size Representation AGENCIES: Department of Defense (DOD), General Services... representation. DATES: Submit comments on or before: May 7, 2012. ADDRESSES: Submit comments identified by Information Collection 9000- 0163, Small Business Size Representation, by any of the following methods...
Majority members' feelings about political representation of muslim immigrants
Verkuyten, Maykel; Hindriks, Paul; Coenders, Marcel
2016-01-01
In three survey experimental studies among national samples of the native Dutch, we examined feelings towards Muslim immigrants' political party representation. The strategy of disengagement (reject political representation) was evaluated most positively, followed by the descriptive representation
Representational content and the reciprocal interplay of agent and environment
Bosse, T.; Jonker, C.M.; Treur, J.
Declarative modelling approaches in principle assume a notion of representation or representational content for the modelling concepts. The notion of representational content as discussed in literature in cognitive science and philosophy of mind shows complications as soon as agent and
Imaging Difference: The Politics of Representation in Multicultural Art Education.
Desai, Dipti
2000-01-01
Examines the notion of "accurate" and "authentic" representations of culture in multicultural art education discourses focusing on two specific areas, museums and aesthetics. Questions the view that by replacing stereotypic representations with purported accurate and authentic representations will fix misunderstandings…
Blob parameter selection for image representation.
Benkarroum, Younes; Herman, Gabor T; Rowland, Stuart W
2015-10-01
A technique for optimizing parameters for image representation using blob basis functions is presented and demonstrated. The exact choice of the basis functions significantly influences the quality of the image representation. It has been previously established that using spherically symmetric volume elements (blobs) as basis functions, instead of the more traditional voxels, yields superior representations of real objects, provided that the parameters that occur in the definition of the family of blobs are appropriately tuned. The technique presented in this paper makes use of an extra degree of freedom, which has been previously ignored, in the blob parameter space. The efficacy of the resulting parameters is illustrated.
Representations of intercourse in American literature
DEFF Research Database (Denmark)
Jensen, Kim Ebensgaard
2014-01-01
This article investigates the representation of sexual intercourse in American literature expressed via the use of fuck as a transitive verb. Its goal is to identify possible trends in the differentiation between men and women's roles and power relations in such literary representations. Drawing...... on theoretical notions from cognitive poetics, the present article assumes that literary representations of intercourse reflect and replicate in readers cognitive-cultural models of intercourse and the roles of, and power relations between, men and women therein. The analysis presented here is quantitative...... for the identification of large-scale patterns in sexual objectification of men or women in American literature....
Representations of Multiple-Valued Logic Functions
Stankovic, Radomir S
2012-01-01
Compared to binary switching functions, multiple-valued functions offer more compact representations of the information content of signals modeled by logic functions and, therefore, their use fits very well in the general settings of data compression attempts and approaches. The first task in dealing with such signals is to provide mathematical methods for their representation in a way that will make their application in practice feasible.Representation of Multiple-Valued Logic Functions is aimed at providing an accessible introduction to these mathematical techniques that are necessary for ap
Shared Representations and the Translation Process
DEFF Research Database (Denmark)
Schaeffer, Moritz; Carl, Michael
2015-01-01
The purpose of the present chapter is to investigate automated processing during translation. We provide evidence from a translation priming study which suggests that translation involves activation of shared lexico-semantic and syntactical representations, i.e., the activation of features of both...... source and target language items which share one single cognitive representation. We argue that activation of shared representations facilitates automated processing. The chapter revises the literal translation hypothesis and the monitor model (Ivir 1981; Toury 1995; Tirkkonen-Condit 2005), and re......-defines it in terms of findings from translation process research. On the basis of the evidence, we propose a recursive model of translation....
Shared Representations and the Translation Process
DEFF Research Database (Denmark)
Schaeffer, Moritz; Carl, Michael
2013-01-01
The purpose of the present paper is to investigate automated processing during translation. We provide evidence from a translation priming study which suggests that translation involves activation of shared lexico-semantic and syntactical representations, i.e., the activation of features of both...... source and target language items which share one single cognitive representation. We argue that activation of shared representations facilitates automated processing. The paper revises the literal translation hypothesis and the monitor model (Ivir 1981; Toury 1995; Tirkkonen-Condit 2005), and re......-defines it in terms of findings from translation process research. On the basis of the evidence, we propose a recursive model of translation....
Geometric Algebra Model of Distributed Representations
Patyk, Agnieszka
Formalism based on GA is an alternative to distributed representation models developed so far: Smolensky's tensor product, Holographic Reduced Representations (HRR), and Binary Spatter Code (BSC). Convolutions are replaced by geometric products interpretable in terms of geometry, which seems to be the most natural language for visualization of higher concepts. This paper recalls the main ideas behind the GA model and investigates recognition test results using both inner product and a clipped version of matrix representation. The influence of accidental blade equality on recognition is also studied. Finally, the efficiency of the GA model is compared to that of previously developed models.
Democracy today: investor's sovereignty or civic representation?
Directory of Open Access Journals (Sweden)
Lutz Wingert
2015-07-01
Full Text Available In many Western democracies, governments, courts and parties in Parliament operate in two opposite ways: (1 On the one hand, they behave cooperatively with powerful investors and associations. (2 On the other hand, they act through authoritarian decrees over citizens lacking such power. The emission of citizen voices thus becomes its remission. Civic representation is necessary for a real (true democracy. This representation updates the voices of citizens and the ingredients of the common good. But, what specifically does this representation mean and what does it require?
Understanding as Integration of Heterogeneous Representations
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.
[Social and cultural representations in epilepsy awareness].
Arborio, Sophie
2015-01-01
Representations relating to epilepsy have evolved over the centuries, but the manifestations of epilepsy awaken archaic images linked to death, violence and disgust. Indeed, the generalised epileptic seizure symbolises a rupture with the surrounding environment, "informs it", through the loss of social codes which it causes. The social and cultural context, as well as medical knowledge, influences the representations of the disease. As a result, popular knowledge is founded on the social and cultural representations of a given era, in a given society. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Action representation: crosstalk between semantics and pragmatics.
Prinz, Wolfgang
2014-03-01
Marc Jeannerod pioneered a representational approach to movement and action. In his approach, motor representations provide both, declarative knowledge about action and procedural knowledge for action (action semantics and action pragmatics, respectively). Recent evidence from language comprehension and action simulation supports the claim that action pragmatics and action semantics draw on common representational resources, thus challenging the traditional divide between declarative and procedural action knowledge. To account for these observations, three kinds of theoretical frameworks are discussed: (i) semantics is grounded in pragmatics, (ii) pragmatics is anchored in semantics, and (iii) pragmatics is part and parcel of semantics. © 2013 Elsevier Ltd. All rights reserved.
Artistic Representation with Pulsed Holography
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.
Distinguishing Representations as Origin and Representations as Input: Roles for Individual Cells
Directory of Open Access Journals (Sweden)
Jonathan C.W. Edwards
2016-09-01
Full Text Available It is widely perceived that there is a problem in giving a naturalistic account of mental representation that deals adequately with meaning, interpretation or significance (semantic content. It is suggested here that this problem may arise partly from the conflation of two vernacular senses of representation: representation-as-origin and representation-as-input. The flash of a neon sign may in one sense represent a popular drink, but to function as representation it must provide an input to a ‘consumer’ in the street. The arguments presented draw on two principles – the neuron doctrine and the need for a venue for ‘presentation’ or ‘reception’ of a representation at a specified site, consistent with the locality principle. It is also argued that domains of representation cannot be defined by signal traffic, since they can be expected to include ‘null’ elements based on non-firing cells. In this analysis, mental representations-as-origin are distributed patterns of cell firing. Each firing cell is given semantic value in its own right - some form of atomic propositional significance – since different axonal branches may contribute to integration with different populations of signals at different downstream sites. Representations-as-input are patterns of local co-arrival of signals in the form of synaptic potentials in dendrites. Meaning then draws on the relationships between active and null inputs, forming ‘scenarios’ comprising a molecular combination of ‘premises’ from which a new output with atomic propositional significance is generated. In both types of representation, meaning, interpretation or significance pivots on events in an individual cell. (This analysis only applies to ‘occurrent’ representations based on current neural activity. The concept of representations-as-input emphasises the need for a ‘consumer’ of a representation and the dependence of meaning on the co-relationships involved in an
Binary Biometric Representation through Pairwise Polar Quantization
Chen, C.; Veldhuis, Raymond N.J.; Tistarelli, M.; Nixon, M.
Binary biometric representations have great significance for data compression and template protection. In this paper, we introduce pairwise polar quantization. Furthermore, aiming to optimize the discrimination between the genuine Hamming distance (GHD) and the imposter Hamming distance (IHD), we
The representational dynamics of remembered projectile locations.
De Sá Teixeira, Nuno Alexandre; Hecht, Heiko; Oliveira, Armando Mónica
2013-12-01
When people are instructed to locate the vanishing location of a moving target, systematic errors forward in the direction of motion (M-displacement) and downward in the direction of gravity (O-displacement) are found. These phenomena came to be linked with the notion that physical invariants are embedded in the dynamic representations generated by the perceptual system. We explore the nature of these invariants that determine the representational mechanics of projectiles. By manipulating the retention intervals between the target's disappearance and the participant's responses, while measuring both M- and O-displacements, we were able to uncover a representational analogue of the trajectory of a projectile. The outcomes of three experiments revealed that the shape of this trajectory is discontinuous. Although the horizontal component of such trajectory can be accounted for by perceptual and oculomotor factors, its vertical component cannot. Taken together, the outcomes support an internalization of gravity in the visual representation of projectiles.
Homogeneous operators and projective representations of the ...
Indian Academy of Sciences (India)
Abstract. This paper surveys the existing literature on homogeneous operators and their relationships with projective representations of P S L ( 2 , R ) and other Lie groups. It also includes a list of open problems in this area.
Stochastic integral representations of quantum martingales on ...
Indian Academy of Sciences (India)
Abstract. In this paper a quantum stochastic integral representation theorem is obtained for unbounded regular martingales with respect to multidimensional quantum noise. This simultaneously extends results of Parthasarathy and Sinha to unbounded martingales and those of the author to multidimensions.
Identities, social representations and critical thinking
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.
Sexing code subversion, theory and representation
Herbst, Claudia
2008-01-01
Critically investigating the gender of programming in popular culture, Sexing Code proposes that the de facto representation of technical ability serves to perpetuate the age-old association of the male with intellect and reason, while identifying the fem
Intermedial Representations in Asian Macbeth-s
National Research Council Canada - National Science Library
Wang, I-Chun; Wang, I-Chun
2011-01-01
In her article "Intermedial representations in Asian Macbeth-s" I-Chun Wang discusses three Asian versions of Macbeths that exemplify the cultural meanings through the interaction of landscape, body...
How initial representations shape coupled learning processes
DEFF Research Database (Denmark)
Puranam, Phanish; Swamy, M.
2016-01-01
. We find that initial representations have important consequences for the success of the coupled learning process, particularly when communication is constrained and individual rates of learning are high. Under these conditions, initial representations that generate incorrect beliefs can outperform......Coupled learning processes, in which specialists from different domains learn how to make interdependent choices among alternatives, are common in organizations. We explore the role played by initial representations held by the learners in coupled learning processes using a formal agent-based model...... one that does not discriminate among alternatives, or even a mix of correct and incorrect representations among the learners. We draw implications for the design of coupled learning processes in organizations. © 2016 INFORMS....
Knowledge Representation for Adaptive Learning Design
Kravcik, Milos; Gasevic, Dragan
2006-01-01
Please, cite this publication as: Kravcik, M. & Gasevic, D. (2006). Knowledge Representation for Adaptive Learning Design. Proceedings of Adaptive Hypermedia. June, Dublin, Ireland. Retrieved June 30th, 2006, from http://dspace.learningnetworks.org
The Politics of Representation in Educational Administration
Mann, Dale
1974-01-01
Reports exploratory research which made use of representational role orientations to analyze the community-related behavior of school administrators in New York State; interviews were conducted with 146 principals, II superintendents, and eight headquarters staff. (Author/JM)
Mental Representations Formed From Educational Website Formats
Energy Technology Data Exchange (ETDEWEB)
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.
The ARES High-level Intermediate Representation
Energy Technology Data Exchange (ETDEWEB)
Moss, Nicholas David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-03-03
The LLVM intermediate representation (IR) lacks semantic constructs for depicting common high-performance operations such as parallel and concurrent execution, communication and synchronization. Currently, representing such semantics in LLVM requires either extending the intermediate form (a signi cant undertaking) or the use of ad hoc indirect means such as encoding them as intrinsics and/or the use of metadata constructs. In this paper we discuss a work in progress to explore the design and implementation of a new compilation stage and associated high-level intermediate form that is placed between the abstract syntax tree and when it is lowered to LLVM's IR. This highlevel representation is a superset of LLVM IR and supports the direct representation of these common parallel computing constructs along with the infrastructure for supporting analysis and transformation passes on this representation.
semantic representation and the translation of poetry
African Journals Online (AJOL)
the actual process of the translation of poetry largely neglected. ... interpretation present in any literary .text - indeed it is claimed that it ensures such infinite ..... enough sample were used, and the method of describing the representation.
Media Representations of Youth Violence in Bulgaria
National Research Council Canada - National Science Library
Stanislava Stoyanova
2012-01-01
This paper presents a study of media representations of youth violence. The way by which media presents the young generation is a reflection of and influence on the development of identity by youth and society's attitude towards youth...
Bodies adapt orientation-independent face representations
Kessler, Ellyanna; Walls, Shawn A.; Ghuman, Avniel S.
2013-01-01
Faces and bodies share a great number of semantic attributes, such as gender, emotional expressiveness, and identity. Recent studies demonstrate that bodies can activate and modulate face perception. However, the nature of the face representation that is activated by bodies remains unknown. In particular, face and body representations have previously been shown to have a degree of orientation specificity. Here we use body-face adaptation aftereffects to test whether bodies activate face repre...
Schoolchildren's social representations on bullying causes
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 the findings, the most prevalent social representation on bullying causes among the children is to view bullying as a reaction to deviance. The seco...
Cohen operators associated with signal representations
Boggiatto, Paolo; Carypis, Evanthia; Oliaro, Alessandro
2017-11-01
In this paper we study the relationships between general quantization rules which yield Cohen operators and the signal time-frequency representations in the Cohen class. After defining a suitable functional setting, we focus on the particular case of the concentration operators which, as the multipliers and Fourier multipliers in the Donoho-Stark uncertainty principle, furnish estimates of the energy concentration on subsets of the time-frequency space. Finally we study the case of positive representations in the Cohen class.
Geometric Analogue of Holographic Reduced Representation
Aerts, Diederik; Czachor, Marek; De Moor, Bart
2007-01-01
Holographic reduced representations (HRR) are based on superpositions of convolution-bound $n$-tuples, but the $n$-tuples cannot be regarded as vectors since the formalism is basis dependent. This is why HRR cannot be associated with geometric structures. Replacing convolutions by geometric products one arrives at reduced representations analogous to HRR but interpretable in terms of geometry. Variable bindings occurring in both HRR and its geometric analogue mathematically correspond to two ...
Geometric Algebra Model of Distributed Representations
Patyk, Agnieszka
2010-01-01
Formalism based on GA is an alternative to distributed representation models developed so far --- Smolensky's tensor product, Holographic Reduced Representations (HRR) and Binary Spatter Code (BSC). Convolutions are replaced by geometric products, interpretable in terms of geometry which seems to be the most natural language for visualization of higher concepts. This paper recalls the main ideas behind the GA model and investigates recognition test results using both inner product and a clipp...
Sparse Representations for the Cocktail Party Problem
Asari, Hiroki; Barak A. Pearlmutter; Zador, Anthony M
2006-01-01
A striking feature of many sensory processing problems is that there appear to be many more neurons engaged in the internal representations of the signal than in its transduction. For example, humans have �30,000 cochlear neurons, but at least 1000 times as many neurons in the auditory cortex. Such apparently redundant internal representations have sometimes been proposed as necessary to overcome neuronal noise. We instead posit that they directly subserve computations of interest. H...
Energy Technology Data Exchange (ETDEWEB)
Davis JE, Eddy MJ, Sutton TM, Altomari TJ
2007-03-01
Solid modeling computer software systems provide for the design of three-dimensional solid models used in the design and analysis of physical components. The current state-of-the-art in solid modeling representation uses a boundary representation format in which geometry and topology are used to form three-dimensional boundaries of the solid. The geometry representation used in these systems is cubic B-spline curves and surfaces--a network of cubic B-spline functions in three-dimensional Cartesian coordinate space. Many Monte Carlo codes, however, use a geometry representation in which geometry units are specified by intersections and unions of half-spaces. This paper describes an algorithm for converting from a boundary representation to a half-space representation.
Mental Representation and Motor Imagery Training
Directory of Open Access Journals (Sweden)
Thomas eSchack
2014-05-01
Full Text Available 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, SDA-M (structural dimensional analysis of mental representation, 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 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.
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.
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.
L-functions and the oscillator representation
Rallis, Stephen
1987-01-01
These notes are concerned with showing the relation between L-functions of classical groups (*F1 in particular) and *F2 functions arising from the oscillator representation of the dual reductive pair *F1 *F3 O(Q). The problem of measuring the nonvanishing of a *F2 correspondence by computing the Petersson inner product of a *F2 lift from *F1 to O(Q) is considered. This product can be expressed as the special value of an L-function (associated to the standard representation of the L-group of *F1) times a finite number of local Euler factors (measuring whether a given local representation occurs in a given oscillator representation). The key ideas used in proving this are (i) new Rankin integral representations of standard L-functions, (ii) see-saw dual reductive pairs and (iii) Siegel-Weil formula. The book addresses readers who specialize in the theory of automorphic forms and L-functions and the representation theory of Lie groups. N
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
Tactile mental body parts representation in obesity.
Scarpina, Federica; Castelnuovo, Gianluca; Molinari, Enrico
2014-12-30
Obese people׳s distortions in visually-based mental body-parts representations have been reported in previous studies, but other sensory modalities have largely been neglected. In the present study, we investigated possible differences in tactilely-based body-parts representation between an obese and a healthy-weight group; additionally we explore the possible relationship between the tactile- and the visually-based body representation. Participants were asked to estimate the distance between two tactile stimuli that were simultaneously administered on the arm or on the abdomen, in the absence of visual input. The visually-based body-parts representation was investigated by a visual imagery method in which subjects were instructed to compare the horizontal extension of body part pairs. According to the results, the obese participants overestimated the size of the tactilely-perceived distances more than the healthy-weight group when the arm, and not the abdomen, was stimulated. Moreover, they reported a lower level of accuracy than did the healthy-weight group when estimating horizontal distances relative to their bodies, confirming an inappropriate visually-based mental body representation. Our results imply that body representation disturbance in obese people is not limited to the visual mental domain, but it spreads to the tactilely perceived distances. The inaccuracy was not a generalized tendency but was body-part related. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Exploring the Structure of Spatial Representations.
Directory of Open Access Journals (Sweden)
Tamas Madl
Full Text Available 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.
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.
A toolbox for representational similarity analysis.
Directory of Open Access Journals (Sweden)
Hamed Nili
2014-04-01
Full Text Available Neuronal population codes are increasingly being investigated with multivariate pattern-information analyses. A key challenge is to use measured brain-activity patterns to test computational models of brain information processing. One approach to this problem is representational similarity analysis (RSA, which characterizes a representation in a brain or computational model by the distance matrix of the response patterns elicited by a set of stimuli. The representational distance matrix encapsulates what distinctions between stimuli are emphasized and what distinctions are de-emphasized in the representation. A model is tested by comparing the representational distance matrix it predicts to that of a measured brain region. RSA also enables us to compare representations between stages of processing within a given brain or model, between brain and behavioral data, and between individuals and species. Here, we introduce a Matlab toolbox for RSA. The toolbox supports an analysis approach that is simultaneously data- and hypothesis-driven. It is designed to help integrate a wide range of computational models into the analysis of multichannel brain-activity measurements as provided by modern functional imaging and neuronal recording techniques. Tools for visualization and inference enable the user to relate sets of models to sets of brain regions and to statistically test and compare the models using nonparametric inference methods. The toolbox supports searchlight-based RSA, to continuously map a measured brain volume in search of a neuronal population code with a specific geometry. Finally, we introduce the linear-discriminant t value as a measure of representational discriminability that bridges the gap between linear decoding analyses and RSA. In order to demonstrate the capabilities of the toolbox, we apply it to both simulated and real fMRI data. The key functions are equally applicable to other modalities of brain-activity measurement. The
External Representations in Service Design : A Distributed Cognition Perspective
Blomkvist, Johan; Segelström, Fabian
2013-01-01
A defining characteristic of service design is the use of external representations which support the design process at various stages. Representations support designers in making intangible aspects of services accessible and shareable, making external representations especially important in service design. External representations are used both to represent current and future states, for the purposes of articulating insights, learning, communicating, collaborating, and maintaining empathy for...
Quantum Analogs of Tensor Product Representations of su(1; 1)*
Groenevelt, W.
2011-01-01
Abstract. We study representations of Uq(su(1; 1)) that can be considered as quantum analogs of tensor products of irreducible -representations of the Lie algebra su(1; 1). We determine the decomposition of these representations into irreducible -representations of Uq(su(1; 1)) by diagonalizing the
8 CFR 1292.1 - Representation of others.
2010-01-01
... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Representation of others. 1292.1 Section... IMMIGRATION REGULATIONS REPRESENTATION AND APPEARANCES § 1292.1 Representation of others. (a) A person entitled to representation may be represented by any of the following: (1) Attorneys in the United States...
15 CFR 2009.1 - Information required in representation.
2010-01-01
... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Information required in representation... OFFICE OF THE UNITED STATES TRADE REPRESENTATIVE PROCEDURES FOR REPRESENTATIONS UNDER SECTION 422 OF THE TRADE AGREEMENTS ACT OF 1979 § 2009.1 Information required in representation. (a) Each representation...
40 CFR 96.13 - Account certificate of representation.
2010-07-01
... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Account certificate of representation... representation. (a) A complete account certificate of representation for a NOX authorized account representative... unit at the source for which the account certificate of representation is submitted. (2) The name...
8 CFR 292.1 - Representation of others.
2010-01-01
... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Representation of others. 292.1 Section 292.1 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS REPRESENTATION AND APPEARANCES § 292.1 Representation of others. (a) A person entitled to representation may be represented by...
Quaternion representation of RNA sequences and tertiary structures.
Magarshak, Y
1993-01-01
A quaternion representation of nucleotides is proposed, with representation of RNA sequences by vectors whose elements are quaternions. Structure and transition matrices in quaternion representation are defined. Correspondence between diagrammatic technique in complex-number and quaternion representation of nucleotides is delineated.
Thomassen, Jacques J.A.; Andeweg, Rudy B.
2004-01-01
In political representation research it is now generally recognised that in parliamentary systems political parties rather than individual members of parliament are the key actors in the process of political representation. However, this focus on political parties might have led to an
Representations of content: psychological foundations and didactical background
Directory of Open Access Journals (Sweden)
Tomáš Janko
2012-03-01
Full Text Available This theoretical study concerns the issue of representations. Representation is a concept used when analysing and explaining human perception, cognition, communication, and learning. Firstly, we introduce the psychological foundations of the concept. Secondly, we clarify the concept of representations and its division in cognitive psychology. We define two basic forms of external representations - verbal and visual. In social psychology, the concept is used for explaining of how much individual cognition is determined by socio-cultural factors. Further, we mention the concept of representations that draws on the Theory of social representations (Moscovici and Vygotsky's ideas. The author seeks to develop a concept of representations usable in didactic discourse. The importance of representations for content-oriented didactics is clarified. We also define the levels on which a teacher reasons when using representations during instruction. Representations of curricular content, which are believed to play an important role when presenting the content to students, are also mentioned.
Asymmetric translation between multiple representations in chemistry
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.
Representational momentum in memory for pitch.
Freyd, J J; Kelly, M H; DeKay, M L
1990-11-01
When a visual pattern is displayed at successively different orientations such that a rotation or translation is implied, an observer's memory for the final position is displaced forward. This phenomenon of representational momentum shares some similarities with physical momentum. For instance, the amount of memory shift is proportional to the implied velocity of the inducing display; representational momentum is specifically proportional to the final, not the average, velocity; representational momentum follows a continuous stopping function for the first 250 ms or so of the retention interval. In a previous paper (Kelly & Freyd, 1987) we demonstrated a forward memory asymmetry using implied changes in pitch, for subjects without formal musical training. In the current paper we replicate our earlier finding and show that the forward memory asymmetry occurs for subjects with formal musical training as well (Experiment 1). We then show the structural similarity between representational momentum in memory for pitch with previous reports of parametric effects using visual stimuli. We report a velocity effect for auditory momentum (Experiment 2), we demonstrate specifically that the velocity effect depends on the implied acceleration (Experiment 3), and we show that the stopping function for auditory momentum is qualitatively the same as that for visual momentum (Experiment 4). We consider the implications of these results for theories of mental representation.
Usage of semantic representations in recognition memory.
Nishiyama, Ryoji; Hirano, Tetsuji; Ukita, Jun
2017-11-01
Meanings of words facilitate false acceptance as well as correct rejection of lures in recognition memory tests, depending on the experimental context. This suggests that semantic representations are both directly and indirectly (i.e., mediated by perceptual representations) used in remembering. Studies using memory conjunction errors (MCEs) paradigms, in which the lures consist of component parts of studied words, have reported semantic facilitation of rejection of the lures. However, attending to components of the lures could potentially cause this. Therefore, we investigated whether semantic overlap of lures facilitates MCEs using Japanese Kanji words in which a whole-word image is more concerned in reading. Experiments demonstrated semantic facilitation of MCEs in a delayed recognition test (Experiment 1), and in immediate recognition tests in which participants were prevented from using phonological or orthographic representations (Experiment 2), and the salient effect on individuals with high semantic memory capacities (Experiment 3). Additionally, analysis of the receiver operating characteristic suggested that this effect is attributed to familiarity-based memory judgement and phantom recollection. These findings indicate that semantic representations can be directly used in remembering, even when perceptual representations of studied words are available.
Designing and evaluating representations to model pedagogy
Directory of Open Access Journals (Sweden)
Elizabeth Masterman
2013-08-01
Full Text Available This article presents the case for a theory-informed approach to designing and evaluating representations for implementation in digital tools to support Learning Design, using the framework of epistemic efficacy as an example. This framework, which is rooted in the literature of cognitive psychology, is operationalised through dimensions of fit that attend to: (1 the underlying ontology of the domain, (2 the purpose of the task that the representation is intended to facilitate, (3 how best to support the cognitive processes of the users of the representations, (4 users’ differing needs and preferences, and (5 the tool and environment in which the representations are constructed and manipulated.Through showing how epistemic efficacy can be applied to the design and evaluation of representations, the article presents the Learning Designer, a constructionist microworld in which teachers can both assemble their learning designs and model their pedagogy in terms of students’ potential learning experience. Although the activity of modelling may add to the cognitive task of design, the article suggests that the insights thereby gained can additionally help a lecturer who wishes to reuse a particular learning design to make informed decisions about its value to their practice.
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
Cognitive representation of orientation: a case study.
Valtonen, Jussi; Dilks, Daniel D; McCloskey, Michael
2008-10-01
Although object orientation in the human brain has been discussed extensively in the literature, the nature of the underlying cognitive representation(s) remains uncertain. We investigated orientation perception in BC, a patient with bilateral occipital and parietal damage from a herpes encephalitis infection. Our results show that in addition to general inaccuracy in discriminating and reproducing line orientations, her errors take the form of left-right mirror reflections across a vertical coordinate axis. We propose that in BC, the cognitive impairment is in failing to represent the direction of tilt for line orientations. Our results suggest that there exists a level of representation in the human brain at which line orientations are represented compositionally, such that the direction of a line orientation's tilt from a vertical mental reference meridian is coded independently of the magnitude of its angular displacement. Reflection errors across a vertical axis were observed both in visual and tactile line orientation tasks, demonstrating that these errors arise at a supra-modal level of representation not restricted to vision, or, alternatively, that visual-like representations are being constructed from the tactile input.
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 =…
Lectures on Iwahori-Hecke Algebras and their Representation Theory
Cherednik, Ivan; Howe, Roger; Lusztig, George
2002-01-01
Two basic problems of representation theory are to classify irreducible representations and decompose representations occuring naturally in some other context. Algebras of Iwahori-Hecke type are one of the tools and were, probably, first considered in the context of representation theory of finite groups of Lie type. This volume consists of notes of the courses on Iwahori-Hecke algebras and their representation theory, given during the CIME summer school which took place in 1999 in Martina Franca, Italy.
Representational Inquiry Competences in Science Games
DEFF Research Database (Denmark)
Magnussen, Rikke
2009-01-01
This chapter concerns the enactment of competences in a particular science learning game Homicide, which is played in lower secondary schools. Homicide is a forensic investigation game in which pupils play police experts solving criminal cases in the space of one week. The game is designed...... to support work with genuine scientific inquiry and to meet the seventh- to tenth grade curriculum objectives for science and Danish education in Danish schools. This paper comprises a presentation of the results of a long-term empirical study done of four school classes who have played the game. The chapter...... includes studies of how students construct visual representations of the cases they investigate and how they use these representations to establish hypotheses and evidence. The term ‘Representational Inquiry Competences' is developed; it refers to the students' ability to construct, productively use...
The error of representation: basic understanding
Directory of Open Access Journals (Sweden)
Daniel Hodyss
2015-01-01
Full Text Available Representation error arises from the inability of the forecast model to accurately simulate the climatology of the truth. We present a rigorous framework for understanding this kind of error of representation. This framework shows that the lack of an inverse in the relationship between the true climatology (true attractor and the forecast climatology (forecast attractor leads to the error of representation. A new gain matrix for the data assimilation problem is derived that illustrates the proper approaches one may take to perform Bayesian data assimilation when the observations are of states on one attractor but the forecast model resides on another. This new data assimilation algorithm is the optimal scheme for the situation where the distributions on the true attractor and the forecast attractors are separately Gaussian, and there exists a linear map between them. The results of this theory are illustrated in a simple Gaussian multivariate model.
Materials Driven Architectural Design and Representation
DEFF Research Database (Denmark)
Kruse Aagaard, Anders
2015-01-01
This paper aims to outline a framework for a deeper connection between experimentally obtained material knowledge and architectural design. While materials and architecture in the process of realisation are tightly connected, architectural design and representation are often distanced from...... the material domain in which the construction eventually will happen. In many cases, it can seem that materials play the role of a selection of building blocks from which a determined architectural vision or representation are tried to be build. Research in materials, materials behaviour and new materials...... another role in relation to architectural production. It is, in this paper, the intention to point at material research as an active initiator in explorative approaches to architectural design methods and architectural representation. This paper will point at the inclusion of tangible and experimental...
Functional disorganization of representations in schizophrenia.
Plagnol, A; Pachoud, B; Claudel, B; Granger, B
1996-01-01
The first part of this article describes a model of disorganization of representations in schizophrenia. We assume that subjects with schizophrenia have some interfering activity in memory. Such an interfering activity induces a functional decontextualization of information and the reciprocal is true. This model accounts for different classes of cognitive troubles that have been observed in schizophrenia. In the second part, we describe a text-comprehension experiment that studies two paradigmatic cases of episodic and semantic contextualization of information: the "compartmentalization" and the "thematization" of fictional narratives. Compartmentalization refers to the way in which representations of different narratives are separated in memory; thematization refers to the way in which representations of one narrative are structured in function of a theme. In our experiment, compartmentalization and thematization are assessed by a method of priming in word recognition. In agreement with our model, the results show that subjects with schizophrenia are impaired in compartmentalization and thematization when compared with anxious-depressed subjects.
Spin-Circuit Representation of Spin Pumping
Roy, Kuntal
2017-07-01
Circuit theory has been tremendously successful in translating physical equations into circuit elements in an organized form for further analysis and proposing creative designs for applications. With the advent of new materials and phenomena in the field of spintronics and nanomagnetics, it is imperative to construct the spin-circuit representations for different materials and phenomena. Spin pumping is a phenomenon by which a pure spin current can be injected into the adjacent layers. If the adjacent layer is a material with a high spin-orbit coupling, a considerable amount of charge voltage can be generated via the inverse spin Hall effect allowing spin detection. Here we develop the spin-circuit representation of spin pumping. We then combine it with the spin-circuit representation for the materials having spin Hall effect to show that it reproduces the standard results as in the literature. We further show how complex multilayers can be analyzed by simply writing a netlist.
SU (N ) Heisenberg model with multicolumn representations
Okubo, Tsuyoshi; Harada, Kenji; Lou, Jie; Kawashima, Naoki
2015-10-01
The SU (N ) symmetric antiferromagnetic Heisenberg model with multicolumn representations on the two-dimensional square lattice is investigated by quantum Monte Carlo simulations. For the representation of a Young diagram with two columns, we confirm that a valence-bond solid (VBS) order appears as soon as the Néel order disappears at N =10 , indicating no intermediate phase. In the case of the representation with three columns, there is no evidence for either the Néel or the VBS ordering for N ≥15 . This is actually consistent with the large-N theory, which predicts that the VBS state immediately follows the Néel state, because the expected spontaneous order is too weak to be detected.
Cognitive and artificial representations in handwriting recognition
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.
Optimal Wavelets for Speech Signal Representations
Directory of Open Access Journals (Sweden)
Shonda L. Walker
2003-08-01
Full Text Available It is well known that in many speech processing applications, speech signals are characterized by their voiced and unvoiced components. Voiced speech components contain dense frequency spectrum with many harmonics. The periodic or semi-periodic nature of voiced signals lends itself to Fourier Processing. Unvoiced speech contains many high frequency components and thus resembles random noise. Several methods for voiced and unvoiced speech representations that utilize wavelet processing have been developed. These methods seek to improve the accuracy of wavelet-based speech signal representations using adaptive wavelet techniques, superwavelets, which uses a linear combination of adaptive wavelets, gaussian methods and a multi-resolution sinusoidal transform approach to mention a few. This paper addresses the relative performance of these wavelet methods and evaluates the usefulness of wavelet processing in speech signal representations. In addition, this paper will also address some of the hardware considerations for the wavelet methods presented.
A course in finite group representation theory
Webb, Peter
2016-01-01
This graduate-level text provides a thorough grounding in the representation theory of finite groups over fields and rings. The book provides a balanced and comprehensive account of the subject, detailing the methods needed to analyze representations that arise in many areas of mathematics. Key topics include the construction and use of character tables, the role of induction and restriction, projective and simple modules for group algebras, indecomposable representations, Brauer characters, and block theory. This classroom-tested text provides motivation through a large number of worked examples, with exercises at the end of each chapter that test the reader's knowledge, provide further examples and practice, and include results not proven in the text. Prerequisites include a graduate course in abstract algebra, and familiarity with the properties of groups, rings, field extensions, and linear algebra.
Numerical model representation and validation strategies
Energy Technology Data Exchange (ETDEWEB)
Dolin, R.M.; Hefele, J.
1997-10-01
This paper describes model representation and validation strategies for use in numerical tools that define models in terms of topology, geometry, or topography. Examples of such tools include Computer-Assisted Engineering (CAE), Computer-Assisted Manufacturing (CAM), Finite Element Analysis (FEA), and Virtual Environment Simulation (VES) tools. These tools represent either physical objects or conceptual ideas using numerical models for the purpose of posing a question, performing a task, or generating information. Dependence on these numerical representations require that models be precise, consistent across different applications, and verifiable. This paper describes a strategy for ensuring precise, consistent, and verifiable numerical model representations in a topographic framework. The main assertion put forth is that topographic model descriptions are more appropriate for numerical applications than topological or geometrical descriptions. A topographic model verification and validation methodology is presented.
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
Spatiotemporal representation of cardiac vectorcardiogram (VCG signals
Directory of Open Access Journals (Sweden)
Yang Hui
2012-03-01
Full Text Available Abstract Background Vectorcardiogram (VCG signals monitor both spatial and temporal cardiac electrical activities along three orthogonal planes of the body. However, the absence of spatiotemporal resolution in conventional VCG representations is a major impediment for medical interpretation and clinical usage of VCG. This is especially so because time-domain features of 12-lead ECG, instead of both spatial and temporal characteristics of VCG, are widely used for the automatic assessment of cardiac pathological patterns. Materials and methods We present a novel representation approach that captures critical spatiotemporal heart dynamics by displaying the real time motion of VCG cardiac vectors in a 3D space. Such a dynamic display can also be realized with only one lead ECG signal (e.g., ambulatory ECG through an alternative lag-reconstructed ECG representation from nonlinear dynamics principles. Furthermore, the trajectories are color coded with additional dynamical properties of space-time VCG signals, e.g., the curvature, speed, octant and phase angles to enhance the information visibility. Results In this investigation, spatiotemporal VCG signal representation is used to characterize various spatiotemporal pathological patterns for healthy control (HC, myocardial infarction (MI, atrial fibrillation (AF and bundle branch block (BBB. The proposed color coding scheme revealed that the spatial locations of the peak of T waves are in the Octant 6 for the majority (i.e., 74 out of 80 of healthy recordings in the PhysioNet PTB database. In contrast, the peak of T waves from 31.79% (117/368 of MI subjects are found to remain in Octant 6 and the rest (68.21% spread over all other octants. The spatiotemporal VCG signal representation is shown to capture the same important heart characteristics as the 12-lead ECG plots and more. Conclusions Spatiotemporal VCG signal representation is shown to facilitate the characterization of space-time cardiac
Context Representation and Fusion: Advancements and Opportunities
Directory of Open Access Journals (Sweden)
Asad Masood Khattak
2014-05-01
Full Text Available 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.
Wavelets for Sparse Representation of Music
DEFF Research Database (Denmark)
Endelt, Line Ørtoft; Harbo, Anders La-Cour
2004-01-01
to the number of vanishing moments of the mother wavelet, and to the smoothness of the signal. In this paper we present the result of applying two classical families of wavelets to a series of musical signals. The purpose is to determine a general relation between the number of vanishing moments of the wavelet......We are interested in obtaining a sparse representation of music signals by means of a discrete wavelet transform (DWT). That means we want the energy in the representation to be concentrated in few DWT coefficients. It is well-known that the decay of the DWT coefficients is strongly related...
The Feynman-Schwinger representation in QCD
Energy Technology Data Exchange (ETDEWEB)
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.
Asymptotic Representations of Quantum Affine Superalgebras
Zhang, Huafeng
2017-08-01
We study representations of the quantum affine superalgebra associated with a general linear Lie superalgebra. In the spirit of Hernandez-Jimbo, we construct inductive systems of Kirillov-Reshetikhin modules based on a cyclicity result that we established previously on tensor products of these modules, and realize their inductive limits as modules over its Borel subalgebra, the so-called q-Yangian. A new generic asymptotic limit of the same inductive systems is proposed, resulting in modules over the full quantum affine superalgebra. We derive generalized Baxter's relations in the sense of Frenkel-Hernandez for representations of the full quantum group.
Implicit Block Diagonal Low-Rank Representation.
Xie, Xingyu; Guo, Xianglin; Liu, Guangcan; Wang, Jun
2017-10-17
While current block diagonal constrained subspace clustering methods are performed explicitly on the original data space, in practice it is often more desirable to embed the block diagonal prior into the reproducing kernel Hilbert feature space by kernelization techniques, as the underlying data structure in reality is usually nonlinear. However, it is still unknown how to carry out the embedding and kernelization in the models with block diagonal constraints. In this work, we shall take a step in this direction. First, we establish a novel model termed Implicit Block Diagonal Low-Rank Representation (IBDLR), by incorporating the implicit feature representation and block diagonal prior into the prevalent Low-Rank Representation (LRR) method. Second, mostly important, we show that the model in IBDLR could be kernelized by making use of a smoothed dual representation and the specifics of a proximal gradient based optimization algorithm. Finally, we provide some theoretical analyses for the convergence of our optimization algorithm. Comprehensive experiments on synthetic and realworld datasets demonstrate the superiorities of our IBDLR over state-of-the-art methods.While current block diagonal constrained subspace clustering methods are performed explicitly on the original data space, in practice it is often more desirable to embed the block diagonal prior into the reproducing kernel Hilbert feature space by kernelization techniques, as the underlying data structure in reality is usually nonlinear. However, it is still unknown how to carry out the embedding and kernelization in the models with block diagonal constraints. In this work, we shall take a step in this direction. First, we establish a novel model termed Implicit Block Diagonal Low-Rank Representation (IBDLR), by incorporating the implicit feature representation and block diagonal prior into the prevalent Low-Rank Representation (LRR) method. Second, mostly important, we show that the model in IBDLR could be
The Spatial Politics of Spatial Representation
DEFF Research Database (Denmark)
Olesen, Kristian; Richardson, Tim
2011-01-01
This paper explores the interplay between the spatial politics of new governance landscapes and innovations in the use of spatial representations in planning. The central premise is that planning experiments with new relational approaches become enmeshed in spatial politics. The case of strategic...... spatial planning in Denmark reveals how fuzzy spatial representations and relational spatial concepts are being used to depoliticise strategic spatial planning processes and to camouflage spatial politics. The paper concludes that, while relational geography might play an important role in building...
Distorted representation in visual tourism research
DEFF Research Database (Denmark)
Jensen, Martin Trandberg
2016-01-01
. On this background, this paper develops the notion ‘distorted representation’ to illustrate that blurred and obscure photos can in fact be intelligible and sensible in understanding tourism. Through an exploration of the overwhelmed and unintended practices of visual fieldwork, distorted representation illustrates...... how photographic materialities, performativities and sensations contribute to new tourism knowledges. While highlighting the potential of distorted representation, the paper posits a cautionary note in regards to the influential role of academic journals in determining the qualities of visual data...
Paired structures and bipolar knowledge representation
DEFF Research Database (Denmark)
Montero, Javier; Bustince, Humberto; Franco, Camilo
In this strictly positional paper we propose a general approach to bipolar knowledge representation, where the meaning of concepts can be modelled by examining their decomposition into opposite and neutral categories. In particular, it is the semantic relationship between the opposite categories...... and at the same time the type of neutrality rising in between opposites. Based on this first level of bipolar knowledge representation, paired structures in fact offer the means to characterize a specific bipolar valuation scale depending on the meaning of the concept that has to be verified. In this sense...
Matrix representation of a Neural Network
DEFF Research Database (Denmark)
Christensen, Bjørn Klint
Processing, by David Rummelhart (Rummelhart 1986) for an easy-to-read introduction. What the paper does explain is how a matrix representation of a neural net allows for a very simple implementation. The matrix representation is introduced in (Rummelhart 1986, chapter 9), but only for a two-layer linear...... network and the feedforward algorithm. This paper develops the idea further to three-layer non-linear networks and the backpropagation algorithm. Figure 1 shows the layout of a three-layer network. There are I input nodes, J hidden nodes and K output nodes all indexed from 0. Bias-node for the hidden...
Orbit Representations from Linear mod 1 Transformations
Directory of Open Access Journals (Sweden)
Carlos Correia Ramos
2012-05-01
Full Text Available We show that every point $x_0in [0,1]$ carries a representationof a $C^*$-algebra that encodes the orbit structure of thelinear mod 1 interval map $f_{eta,alpha}(x=eta x +alpha$. Such $C^*$-algebra is generated by partial isometries arising from the subintervals of monotonicity of the underlying map $f_{eta,alpha}$. Then we prove that such representation is irreducible. Moreover two such of representations are unitarily equivalent if and only if the points belong to the same generalized orbit, for every $alphain [0,1[$ and $etageq 1$.
Robot Motion Planning: A Distributed Representation Approach
1989-05-01
MaN’ 1989 Report No. STAN-CS-89-1257 0 00 Robot Motion Planning : a) A Distributed Representation Approach Q 0 by Jerome Barraquand and Jean-Claude...Include Security Classification) ES Robot Motion Planning : A Distributed Representation Approach 12 PERSON" bRW~ rraquand and Jean-Claude Latombe...allow to generate plans in real-time, even for 10 DOF arms. Real-time motion planning for complex robotics systems opens new perspectives on some key
Knowledge representation an approach to artificial intelligence
Bench-Capon, TJM
1990-01-01
Although many texts exist offering an introduction to artificial intelligence (AI), this book is unique in that it places an emphasis on knowledge representation (KR) concepts. It includes small-scale implementations in PROLOG to illustrate the major KR paradigms and their developments.****back cover copy:**Knowledge representation is at the heart of the artificial intelligence enterprise: anyone writing a program which seeks to work by encoding and manipulating knowledge needs to pay attention to the scheme whereby he will represent the knowledge, and to be aware of the consequences of the ch
Knowledge representation and natural language processing
Energy Technology Data Exchange (ETDEWEB)
Weischedel, R.M.
1986-07-01
In principle, natural language and knowledge representation are closely related. This paper investigates this by demonstrating how several natural language phenomena, such as definite reference, ambiguity, ellipsis, ill-formed input, figures of speech, and vagueness, require diverse knowledge sources and reasoning. The breadth of kinds of knowledge needed to represent morphology, syntax, semantics, and pragmatics is surveyed. Furthermore, several current issues in knowledge representation, such as logic versus semantic nets, general-purpose versus special-purpose reasoners, adequacy of first-order logic, wait-and-see strategies, and default reasoning, are illustrated in terms of their relation to natural language processing and how natural language impact the issues.
Data Representation, Coding, and Communication Standards.
Amin, Milon; Dhir, Rajiv
2015-06-01
The immense volume of cases signed out by surgical pathologists on a daily basis gives little time to think about exactly how data are stored. An understanding of the basics of data representation has implications that affect a pathologist's daily practice. This article covers the basics of data representation and its importance in the design of electronic medical record systems. Coding in surgical pathology is also discussed. Finally, a summary of communication standards in surgical pathology is presented, including suggested resources that establish standards for select aspects of pathology reporting. Copyright © 2015 Elsevier Inc. All rights reserved.
De Visscher, Alice; Noël, Marie-Pascale; De Smedt, Bert
2016-12-01
Arithmetic facts, in particular multiplication tables, are thought to be stored in long-term memory and to be interference prone. At least two representations underpinning these arithmetic facts have been suggested: a physical representation of the digits and a numerical magnitude representation. We hypothesized that both representations are possible sources of interference that could explain individual differences in multiplication fact performance and/or in strategy use. We investigated the specificity of these interferences on arithmetic fact retrieval and explored the relation between interference and performance on the different arithmetic operations and on general mathematics achievement. Participants were 79 fourth-grade children (M age =9.6 years) who completed a products comparison and a multiplication production task with verbal strategy reports. Performances on a speeded calculation test including the four operations and on a general mathematics achievement test were also collected. Only the interference coming from physical representations was a significant predictor of the performance across multiplications. However, both the magnitude and physical representations were unique predictors of individual differences in multiplication. The frequency of the retrieval strategy across multiplication problems and across individuals was determined only by the physical representation, which therefore is suggested as being responsible for memory storage issues. Interestingly, this impact of physical representation was not observed when predicting performance on subtraction or on general mathematical achievement. In contrast, the impact of the numerical magnitude representation was more general in that it was observed across all arithmetic operations and in general mathematics achievement. Copyright © 2016 Elsevier Inc. All rights reserved.
Representation of physical activity domains and sedentary ...
African Journals Online (AJOL)
Schools play an important role in promoting active lifestyles among children. The aim of this study was to evaluate the representation of physical activity (PA) and sedentary behaviours (SBs) in the images of physical education (PE) textbooks. The initial sample was composed of 1 094 images from Spanish PE textbooks.
Media representations of Zimbabwean women migrants
African Journals Online (AJOL)
'Kids sold, desperate moms need cash' : Media representations of Zimbabwean women migrants. ... contexts in order to account for the migrant women's voices of resilience, defiance and victimhood and of agency, against the normalising and marginalising influences of political institutions and national border controls.
On generic representation of implicit induction procedures
D. Naidich
1996-01-01
textabstractWe develop a generic representation of implicit induction proof procedures within the cover set induction framework. Our work further develops the approach of cover set induction on propositional orderings. We show that in order to represent a substantially wide range of implicit
Bodies adapt orientation-independent face representations.
Kessler, Ellyanna; Walls, Shawn A; Ghuman, Avniel S
2013-01-01
Faces and bodies share a great number of semantic attributes, such as gender, emotional expressiveness, and identity. Recent studies demonstrate that bodies can activate and modulate face perception. However, the nature of the face representation that is activated by bodies remains unknown. In particular, face and body representations have previously been shown to have a degree of orientation specificity. Here we use body-face adaptation aftereffects to test whether bodies activate face representations in an orientation-dependent manner. Specifically, we used a two-by-two design to examine the magnitude of the body-face aftereffect using upright and inverted body adaptors and upright and inverted face targets. All four conditions showed significant body-face adaptation. We found neither a main effect of body orientation nor an interaction between body and face orientation. There was a main effect of target face orientation, with inverted target faces showing larger aftereffects than upright target faces, consistent with traditional face-face adaptation. Taken together, these results suggest that bodies adapt and activate a relatively orientation-independent representation of faces.
Multimodal representations in collaborative history learning
Prangsma, M.E.
2007-01-01
This dissertation focuses on the question: How does making and connecting different types of multimodal representations affect the collaborative learning process and the acquisition of a chronological frame of reference in 12 to 14-year olds in pre vocational education? A chronological frame of
The Weierstrass–Enneper representation using hodographic ...
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
RUKMINI DEY. School of Mathematics, Harish-Chandra Research Institute, Allahabad 211 019, India. E-mail: rkmn@mri.ernet.in. MS received 19 June 2002; revised 10 October 2002. Abstract. In this paper we obtain the general solution to the minimal surface equation, namely its local Weierstrass–Enneper representation, ...
Textbooks as crafted representational objects: A comparative ...
African Journals Online (AJOL)
Textbooks as crafted representational objects: A comparative analysis of Grade 7 home language textbooks for isiZulu, Sepedi, Sesotho, Afrikaans and English. ... in each one, in the mediation strategies selected and in the subject positions that each design team offers to learners as adolescent local and global citizens.
Schoolchildren's Social Representations on Bullying Causes
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…
SEMANTIC REPRESENTATION AND THE TRANSLATION OF ...
African Journals Online (AJOL)
on its syntactic structure. The text then enters a stage of semantic analysis, where the task of "concept recovery" is undertaken. The next stage consists of a pragmatic analysis in which the communicative function of the text is determined. A "semantic representation" of the text is thus created in the mind of the reader, clause ...
Cultural Representation and Intercultural Interaction: Nigerian ...
African Journals Online (AJOL)
Using some Nollywood films as primary data, I intend to examine the image representation of the traditional and Western Nigerian in Nollywood. This paper intends to find out to what extent intercultural interactions can “transform” the Nigerian woman and still leave her “acceptable” in the light of the cultures and traditions.
Collective form generation through visual participatory representation
DEFF Research Database (Denmark)
Day, Dennis; Sharma, Nishant; Punekar, Ravi
2012-01-01
In order to inspire and inform designers with the users data from participatory research, it may be important to represent data in a visual format that is easily understandable to the designers. For a case study in vehicle design, the paper outlines visual representation of data and the use...
Development of ontological knowledge representation: learning ...
African Journals Online (AJOL)
This paper presents the development of an ontological knowledge organization and representation, and explains how application of appropriate methods for its visualization can lead to meaningful learning. We have applied systemic diagrams (SD) as a method of visualizing ontological knowledge organization.
Conceptual Metonymy and Lexicographic Representation (2012)
African Journals Online (AJOL)
user
of metonymy can benefit the representation of metonymic lexemes in peda- gogical lexicography' (2012: 16). The book is composed of four chapters which encompass a theoretical overview of metonymy and an analysis of the microstructure, including defini- tions, examples and codes, of five English Monolingual Learner's ...
Non-uniform tube representation of proteins
DEFF Research Database (Denmark)
Hansen, Mikael Sonne
might not correctly capture volume exclusion - of crucial importance when trying to understand a proteins $3$d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X...
Non-Uniform Tube Representation of Proteins
DEFF Research Database (Denmark)
Hansen, Mikael Sonne
might not correctly capture volume exclusion - of crucial importance when trying to understand a protein's 3d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X...
Representations of the Human Circulatory System
Lopez-Manjon, Asuncion; Angon, Yolanda Postigo
2009-01-01
There is no agreement about the robustness of intuitive representations of the circulatory system and their susceptibility to change by instruction. In this paper, we analyse to what extent students with varying degrees of biology instruction and different ages (High School Health Science and Social Science students and first and final year…
Digital Art Making as a Representational Process
Halverson, Erica Rosenfeld
2013-01-01
In this article I bring artistic production into the learning sciences conversation by using the production of representations as a bridging concept between art making and the new literacies. Through case studies with 4 youth media arts organizations across the United States I ask how organizations structure the process of producing…
Phonological Representations and Early Literacy in Chinese
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…
FILMIC REPRESENTATION IN POSTCOLONIAL DISCOURSE: A ...
African Journals Online (AJOL)
Representation or images formed in the mind have vast implications for real people in real context. The works of postcolonial writers and artists attest to the continual attempts to counter all colonial subversions. In Myth, Literature and the African World (1976), Soyinka elaborates clearly that Africa is a cultural entity, a world ...
semantic representation and the translation of poetry
African Journals Online (AJOL)
coincide with the semantic representation of the poem in the mind of the reader, or whether this textual world is a fixed and objective configuration. Certainly the implication is rather the latter case, which does not however remove the possibility for infinite interpretation present in any literary .text - indeed it is claimed that it ...
Representations of Sound in American Deaf Literature
Rosen, Russell S.
2007-01-01
Sound plays a prominent role in narrative description of characters and environs in mainstream American literature. A review of American Deaf literature shows that the representations of sound held for deaf writers are in extensional and oppositional terms. American deaf writers, in their descriptions of entities, characters, functions, and…
Review of Impediments to Women's Representation and ...
African Journals Online (AJOL)
The paper is a review of literature on impediments to women's representation and participation in university leadership after the introduction of a number of gender sensitive policies. A number of measures have been put in place to address gender inequalities in leadership (The Sixth African Development Forum report ...
Comrades' power: Student representation and activism in ...
African Journals Online (AJOL)
Mwangi J. Macharia: Comrades' power: Student representation and activism in universities in Kenya 21. Methodological approach. This article is largely descriptive and exploratory in design (cf. Creswell, 1998; Babbie,. 2001; Bogdan & Bilken, 2003). It draws on available literature related to student governance, student ...
Retrieval and Representation of Nucleotide Sequence of ...
African Journals Online (AJOL)
Umar et al.: Retrieval and Representation of Nucleotide Sequence of Saccharomyces cerevisiae Cystathionine ............. 28. GenBank, information describing each sequence entry is given, including literature references, information about the function of the sequence, location of mRNA and coding regions, and position of ...
REPRESENTATION OF PHYSICAL ACTIVITY DOMAINS AND ...
African Journals Online (AJOL)
Autor
aim of this study was to evaluate the representation of physical activity (PA) and sedentary behaviours ... A review of the literature has shown that a lack of PA and high amount of Sedentary. Behaviour (SB) are ..... occurring during adolescence, especially for the girls (Kwan et al., 2012), it is particularly important to avoid ...
The spatial representation of market information
DeSarbo, WS; Degeratu, AM; Wedel, M; Saxton, MK
2001-01-01
To be used effectively, market knowledge and information must be structured and represented in ways that are parsimonious and conducive to efficient managerial decision making. This manuscript proposes a new latent structure spatial model for the representation of market information that meets this
Representation of Legal Knowledge for Conceptual Retrieval.
Cross, George R.; deBessonet, Cary G.
1985-01-01
Describes traditional legal information retrieval systems--Juris, Lexis, Westlaw--and several new rule-based, knowledge-based, legal knowledge reasoning, and analytical legal information systems--Waterman and Peterson's Legal Decisionmaking System, Hafner's Legal Information Retrieval System, McCarty's TAXMAN, and the deBessonet representation of…
Efficient Representation of Timed UML 2 Interactions
DEFF Research Database (Denmark)
Knapp, Alexander; Störrle, Harald
2014-01-01
UML 2 interactions describe system behavior over time in a declarative way. The standard approach to defining their formal semantics enumerates traces of events; other representation formats, like Büchi automata or prime event structures, have been suggested, too. We describe another, more succinct...
Graphic Representations as Tools for Decision Making.
Howard, Judith
2001-01-01
Focuses on the use of graphic representations to enable students to improve their decision making skills in the social studies. Explores three visual aids used in assisting students with decision making: (1) the force field; (2) the decision tree; and (3) the decision making grid. (CMK)
Knowledge representation in metabolic pathway databases
Stobbe, M.D.; Jansen, G.A.; Moerland, P.D.; van Kampen, A.H.C.
2014-01-01
The accurate representation of all aspects of a metabolic network in a structured format, such that it can be used for a wide variety of computational analyses, is a challenge faced by a growing number of researchers. Analysis of five major metabolic pathway databases reveals that each database has
Locally Situated Digital Representation of Indigenous Knowledge
DEFF Research Database (Denmark)
Winschiers-Theophilus, Heike; Jensen, Kasper Løvborg; Rodil, Kasper
2012-01-01
representation based on experiences from a longitudinal community-centred research project in rural Africa. In a quest to shape design from a locally situated viewpoint, we co-design a 3D visualization of an African village with its inhabitants. Prior invisible local perspectives, as well as dominant designer...
Social representations about science among students
Directory of Open Access Journals (Sweden)
Špela Šoštarič
2003-09-01
Full Text Available The article presents the results of a comparative study on social representations about science among students of social and natural sciences. My interest was focused mainly on the scientific metaparadigms we can find behind these representations, especially positivism and constructivism. The basic epistemological difference between the two is in accepting or rejecting the possibility of acquiring objective knowledge about reality. In the first part of the research I used my own questionnaire about social representations about science and scientific knowledge. In the second part the interviews were performed with students who had obtained extreme scores on the questionnaire – in any of the two directions. The results of the questionnaire indicated that the students of natural sciences hold more positivistic representations and the students of social sciences more constructivistic ones. In the interviews these differences disappeared. Surprising resemblances were evident especially at the ontological and epistemological levels. I try to examine these results from the viewpoint of Tajfel's social identity theory and Bečaj's understanding of the structural model of the enviroment.
Atypical Neural Self-Representation in Autism
Lombardo, Michael V.; Chakrabarti, Bhismadev; Bullmore, Edward T.; Sadek, Susan A.; Pasco, Greg; Wheelwright, Sally J.; Suckling, John; Baron-Cohen, Simon
2010-01-01
The "self" is a complex multidimensional construct deeply embedded and in many ways defined by our relations with the social world. Individuals with autism are impaired in both self-referential and other-referential social cognitive processing. Atypical neural representation of the self may be a key to understanding the nature of such impairments.…
Coordinating different representations in the hippocampus
Czech Academy of Sciences Publication Activity Database
Kelemen, Eduard; Fenton, A.A.
2016-01-01
Roč. 129, Mar 2016 (2016), s. 50-59 ISSN 1074-7427 R&D Projects: GA ČR(CZ) GA14-03627S Institutional support: RVO:67985823 Keywords : dynamic functional grouping * multiple representations * cognitive control * hippocampus * overdispersion Subject RIV: FH - Neurology Impact factor: 3.543, year: 2016
Twentieth-Century Art: Issues of Representation.
Springer, Julie
1990-01-01
Presents lesson plans designed for secondary students that assess the role of naturalistic representation in twentieth-century art by examining the artwork of four artists: Pablo Picasso, Rene Magritte, David Smith, and Jackson Pollock. Provides background information on each illustration, and outlines discussion and art production activities for…
Unilateral Vestibular Loss Impairs External Space Representation
Borel, Liliane; Redon-Zouiteni, Christine; Cauvin, Pierre; Dumitrescu, Michel; Devèze, Arnaud; Magnan, Jacques; Péruch, Patrick
2014-01-01
The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal) and far (extrapersonal) spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation), and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss. PMID:24523916
Unilateral vestibular loss impairs external space representation.
Directory of Open Access Journals (Sweden)
Liliane Borel
Full Text Available The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal and far (extrapersonal spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation, and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss.
Topological methods in Galois representation theory
Snaith, Victor P
2013-01-01
An advanced monograph on Galois representation theory by one of the world's leading algebraists, this volume is directed at mathematics students who have completed a graduate course in introductory algebraic topology. Topics include abelian and nonabelian cohomology of groups, characteristic classes of forms and algebras, explicit Brauer induction theory, and much more. 1989 edition.
Topology optimization using an explicit interface representation
DEFF Research Database (Denmark)
Christiansen, Asger Nyman; Nobel-Jørgensen, Morten; Aage, Niels
2014-01-01
used for both finite element calculations and shape representation. In addition, the approach unifies shape and topology optimization in a complementary optimization strategy. The shape is optimized on the basis of the gradient-based optimization algorithm MMA whereas holes are introduced using...
Attentional control and competition between episodic representations
Akyürek, Elkan G.; Schubö, Anna; Hommel, Bernhard
The relationship between attentional control and episodic representation was investigated in six experiments that employed a variant of the classic attentional blink paradigm. We introduced a task-irrelevant (unpredictive) color match between the first and second target stimulus in a three-stream
Generative and Filtering Approaches for Overcomplete Representations
DEFF Research Database (Denmark)
Petersen, Kaare Brandt; Hao, Jiucang; Lee, Te-Won
2005-01-01
We investigate the properties of the generative and filtering approach to overcomplete representations. A Mixture of Gaussian (MoG) density model is used to derive estimation rules for an energy based model, which estimate the filtering matrix, as well as a generative model which estimate...
Analysing cartographic representations in spatial planning
Dühr, S.
2015-01-01
Spatial planning maps are powerful instruments to frame discussions in plan-making processes and for the visualisation of existing and envisaged land uses on which future decisions are based. Yet despite their communicative potential, the role of cartographic representations has received less
Plasticity of the hippocampal place cell representation.
Jeffery, Kathryn J; Hayman, Robin
2004-01-01
The role of the hippocampus in the representation of 'place' has been attributed to the place cells, whose spatially localised firing suggests their participation in forming a cognitive map of the environment. That this map is necessary for spatial memory formation is indicated by the propensity of almost all navigational tasks to be disrupted by hippocampal damage. The hippocampus has also long been implicated in the formation of episodic memories, and the unusually plastic nature of hippocampal synapses testifies to its probable mnemonic role. Arguably, the place cell representation should, if it is to support spatial learning, be modifiable according to known principles of synaptic reorganization. The present article reviews evidence that the place cell representation is indeed plastic, and that its plasticity depends on the same neurobiological mechanisms known to underlie experimentally induced synaptic plasticity. Inferences are drawn regarding the architecture of the spatial representation and the principles by which it is modified. Spatial learning is promising to be the first kind of memory which is completely understood at all levels, from molecular through circuitry to behaviour and beyond.
Mind games: the mental representation of conflict.
Halevy, Nir; Chou, Eileen Y; Murnighan, J Keith
2012-01-01
Perception and misperception play a pivotal role in conflict and negotiation. We introduce a framework that explains how people think about their outcome interdependence in conflict and negotiation and how their views shape their behavior. Seven studies show that people's mental representations of conflict are predictably constrained to a small set of possibilities with important behavioral and social consequences. Studies 1 and 2 found that, when prompted to represent a conflict in matrix form, more than 70% of the people created 1 of 4 archetypal mixed-motive games (out of 576 possibilities): Maximizing Difference, Assurance, Chicken, and Prisoner's Dilemma. Study 3 demonstrated that these mental representations relate in predictable ways to negotiators' fixed-pie perceptions. Studies 4-6 showed that these mental representations shape individuals' behavior and interactions with others, including cooperation, perspective taking, and use of deception in negotiation, and through them, conflict's outcomes. Study 7 found that the games that people think they are playing influence how their counterparts see them, as well as their counterparts' negotiation expectations. Overall, the findings document noteworthy regularities in people's mental representations of outcome interdependence in conflict and illustrate that 4 archetypal games can encapsulate fundamental psychological processes that emerge repeatedly in conflict and negotiation.
Accounting Knowledge Representation in PROLOG Language
Directory of Open Access Journals (Sweden)
Bogdan Patrut
2010-03-01
Full Text Available This paper presents some original techniques for implementing accounting knowledge in PROLOG language. We will represent rules of operation of accounts, the texts of accounting operations, and how to compute the depreciation.Keywords: accounting, knowledge representation, PROLOG, depreciation, natural language processing
Representations of stem cell clinics on Twitter.
Kamenova, Kalina; Reshef, Amir; Caulfield, Timothy
2014-12-01
The practice of travelling abroad to receive unproven and unregulated stem cell treatments has become an increasingly problematic global phenomenon known as 'stem cell tourism'. In this paper, we examine representations of nine major clinics and providers of such treatments on the microblogging network Twitter. We collected and conducted a content analysis of Twitter posts (n = 363) by these establishments and by other users mentioning them, focusing specifically on marketing claims about treatment procedures and outcomes, discussions of safety and efficacy of stem cell transplants, and specific representations of patients' experiences. Our analysis has shown that there were explicit claims or suggestions of benefits associated with unproven stem cell treatments in approximately one third of the tweets and that patients' experiences, whenever referenced, were presented as invariably positive and as testimonials about the efficacy of stem cell transplants. Furthermore, the results indicated that the tone of most tweets (60.2 %) was overwhelmingly positive and there were rarely critical discussions about significant health risks associated with unproven stem cell therapies. When placed in the context of past research on the problems associated with the marketing of unproven stem cell therapies, this analysis of representations on Twitter suggests that discussions in social media have also remained largely uncritical of the stem cell tourism phenomenon, with inaccurate representations of risks and benefits for patients.
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. Copyright © 2015 Elsevier Ltd. All rights reserved.
Describing Images using Inferred Visual Dependency Representations
D. Elliott (Desmond); A.P. de Vries (Arjen)
2015-01-01
textabstractThe Visual Dependency Representation (VDR) is an explicit model of the spatial relationships between objects in an image. In this paper we present an approach to training a VDR Parsing Model without the extensive human supervision used in previous work. Our approach is to find the
Euler Sums and Contour Integral Representations
Flajolet, Philippe; Salvy, Bruno
1996-01-01
This paper develops an approach to the evaluation of Euler sums involving harmonic numbers either linearly or nonlinearly. We give explicit formul{æ} for certain classes of Euler sums in terms of values of the Riemann zeta function at positive integers. The approach is based on simple contour integral representations and residue computations.
Representations of space based on haptic input
Zuidhoek, S.
2005-01-01
The present thesis focused on the representations of grasping space based on haptic input. We aimed at identifying their characteristics, and the underlying neurocognitive processes and mechanisms. To this end, we studied the systematic distortions in performance on several orientation perception
On Directional Measurement Representation in Orbit Determination
2016-09-13
Precision Orbit Determination (OD) is often critical for successful satellite operations supporting a wide variety of missions. Directional or angles only...representations. The three techniques are then compared experimentally for a geostationary and a low Earth orbit satellite using simulated data to evaluate their... Orbit Determination (OD) is often critical for successful satellite operations supporting a wide variety of missions. Precision OD involves
Spectral Representations of Fingerprint Minutiae Subsets
Xu, H.; Veldhuis, Raymond N.J.
2009-01-01
The investigation of the privacy protection of biometric templates gains more and more attention. The spectral minutiae representation is a novel method to represent a minutiae set as a fixed-length feature vector, which is invariant to translation, and in which rotation and scaling become
Investigating self-representation with virtual reality
Ma, Ke
2016-01-01
The main issue addressed in this thesis is the degree to which the representation of our body is flexible, and what possible implication this has. By using the virtual hand illusion (VHI) paradigm, we provided evidence for a dissociation between subjective ownership perception and the skin
Audio Spatial Representation Around the Body.
Aggius-Vella, Elena; Campus, Claudio; Finocchietti, Sara; Gori, Monica
2017-01-01
Studies have found that portions of space around our body are differently coded by our brain. Numerous works have investigated visual and auditory spatial representation, focusing mostly on the spatial representation of stimuli presented at head level, especially in the frontal space. Only few studies have investigated spatial representation around the entire body and its relationship with motor activity. Moreover, it is still not clear whether the space surrounding us is represented as a unitary dimension or whether it is split up into different portions, differently shaped by our senses and motor activity. To clarify these points, we investigated audio localization of dynamic and static sounds at different body levels. In order to understand the role of a motor action in auditory space representation, we asked subjects to localize sounds by pointing with the hand or the foot, or by giving a verbal answer. We found that the audio sound localization was different depending on the body part considered. Moreover, a different pattern of response was observed when subjects were asked to make actions with respect to the verbal responses. These results suggest that the audio space around our body is split in various spatial portions, which are perceived differently: front, back, around chest, and around foot, suggesting that these four areas could be differently modulated by our senses and our actions.
Learning Semantic-Aligned Action Representation.
Ni, Bingbing; Li, Teng; Yang, Xiaokang
2017-08-31
A fundamental bottleneck for achieving highly discriminative action representation is that local motion/appearance features are usually not semantic aligned. Namely, a local feature, such as a motion vector or motion trajectory, does not possess any attribute that indicates which moving body part or operated object it is associated with. This mostly leads to global feature pooling/representation learning methods that are often too coarse. Inspired by the recent success of end-to-end (pixel-to-pixel) deep convolutional neural networks (DCNNs), in this paper, we first propose a DCNN architecture, which maps a human centric image region onto human body part response maps. Based on these response maps, we propose a second DCNN, which achieves semantic-aligned feature representation learning. Prior knowledge that only a few parts are responsible for a certain action is also utilized by introducing a group (part) sparseness prior during feature learning. The learned semantic-aligned feature not only boosts the discriminative capability of action representation, but also possesses the good nature of robustness to pose variations and occlusions. Finally, an iterative mining method is employed for learning discriminative action primitive detectors. Extensive experiments on action recognition benchmarks demonstrate a superior recognition performance of the proposed framework.
On modular Galois representations modulo prime powers
DEFF Research Database (Denmark)
Chen, Imin; Kiming, Ian; Wiese, Gabor
2013-01-01
by p). We also study eigenforms mod pm corresponding to the above three notions. Assuming residual irreducibility, we utilize a theorem of Carayol to show that one can attach a Galois representation mod pm to any "dc-weak" eigenform, and hence to any eigenform mod pm in any of the three senses. We show...
Gender Representation in Geography: Singapore. Symposium
Yeoh, Brenda S. A.; Huang, Shirlena; Wong, Theresa
2004-01-01
In Singapore, geography emerged as a strongly masculinist university discipline during the interwar years under colonial rule. Localizing staff hires in the postcolonial era did not immediately produce gender-balanced staff profiles. Instead, a more equitable gender representation was achieved only in the last decade, following the increasing…
Bodies adapt orientation-independent face representations
Directory of Open Access Journals (Sweden)
Ellyanna eKessler
2013-07-01
Full Text Available Faces and bodies share a great number of semantic attributes, such as gender, emotional expression, and identity. Recent studies demonstrate that bodies can activate and modulate face perception. However, the nature of the face representation that is activated by bodies remains unknown. In particular, face and body representations have previously been shown to have a degree of orientation specificity. Here we use body-face adaptation aftereffects to test whether bodies activate face representations in an orientation-dependent manner. Specifically, we used a two-by-two design to examine the magnitude of the body-face aftereffect using upright and inverted body adaptors and upright and inverted face targets. All four conditions showed significant body-face adaptation. We found neither a main effect of body orientation nor an interaction between body and face orientation. There was a main effect of target face orientation, with inverted target faces showing larger aftereffects than upright target faces, consistent with traditional face-face adaptation. Taken together, these results suggest that bodies adapt and activate a relatively orientation-invariant representation of faces.
development of ontological knowledge representation: learning ...
African Journals Online (AJOL)
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what is the connection among knowledge elicitation, analysis, representation and organization, can be explained by Piaget's model of equilibration and cognitive schemes (4). Piaget's model of equilibration describes a process in which people accept new information from the environment (knowledge elicitation), how they ...
Software GOLUCA: Knowledge Representation in Mental Calculation
Casas-Garcia, Luis M.; Luengo-Gonzalez, Ricardo; Godinho-Lopes, Vitor
2011-01-01
We present a new software, called Goluca (Godinho, Luengo, and Casas, 2007), based on the technique of Pathfinder Associative Networks (Schvaneveldt, 1989), which produces graphical representations of the cognitive structure of individuals in a given field knowledge. In this case, we studied the strategies used by teachers and its relationship…
A 'more-than-representational' mapping study
DEFF Research Database (Denmark)
Lanng, Ditte Bendix
2017-01-01
through a concrete mapping study of a suburban site of lived mobilities and mundane architectures. From this standpoint the paper elaborates three central attentions of mapping as a creative and reflected more-than-representational tool in urban design: the evocations of eventfulness of sites, intricate...
Toward a Theory of Representation Design
1989-05-01
understanding. This report describes research done at the Artificial Inteligence Laboratory of the Massachusetts Institute of Technology. Support for this...AD-A210 885 Technical Report 1128 Toward a Theory of Representation Design Jeffrey Van Baale MIT Artificial Intelligence Laboratory DTIC ELECTE A... Artificial Intelligence Laboratory 545 Technology Square Cambridge, MA 02139 11. CONTROLLING OFFICE NAME AND ADDRESS 11. REPORT DATE Advanced Research
On functional representations of the conformal algebra
Energy Technology Data Exchange (ETDEWEB)
Rosten, Oliver J.
2017-07-15
Starting with conformally covariant correlation functions, a sequence of functional representations of the conformal algebra is constructed. A key step is the introduction of representations which involve an auxiliary functional. It is observed that these functionals are not arbitrary but rather must satisfy a pair of consistency equations corresponding to dilatation and special conformal invariance. In a particular representation, the former corresponds to the canonical form of the exact renormalization group equation specialized to a fixed point whereas the latter is new. This provides a concrete understanding of how conformal invariance is realized as a property of the Wilsonian effective action and the relationship to action-free formulations of conformal field theory. Subsequently, it is argued that the conformal Ward Identities serve to define a particular representation of the energy-momentum tensor. Consistency of this construction implies Polchinski's conditions for improving the energy-momentum tensor of a conformal field theory such that it is traceless. In the Wilsonian approach, the exactly marginal, redundant field which generates lines of physically equivalent fixed points is identified as the trace of the energy-momentum tensor. (orig.)
Teaching Representation Translations with Magnetic Field Experiments
Tillotson, Wilson Andrew; McCaskey, Timothy; Nasser, Luis
2017-01-01
We have developed a laboratory exercise designed to help students translate between different field representations. It starts with students qualitatively mapping field lines for various bar magnet configurations and continues with a Hall probe experiment in which students execute a series of scaffolded tasks, culminating in the prediction and…
Group representations in indefinite metric spaces
van den Broek, P.M.; Denardo, G.; Ghirardi, G.; Weber, T.
1984-01-01
A group G of symmetry transformations of the rays of an indefinite metric space V with metric operator eta leads to a projective representation U of G in V in terms of eta-unitary, eta-antiunitary, eta-pseudounitary, and eta-pseudoantiunitary operators. We investigate the restrictions which are put
Group representations in indefinite metric spaces
van den Broek, P.M.
A group G of symmetry transformations of the rays of an indefinite metric space V with metric operator eta leads to a projective representation U of G in V in terms of eta-unitary, eta-antiunitary, eta-pseudounitary, and eta-pseudoantiunitary operators. We investigate the restrictions which are put
Acting together: Representations and coordination processes
DEFF Research Database (Denmark)
Vesper, Cordula; Sebanz, Natalie
2016-01-01
findings from experimental studies that shed light on general coordination strategies, representations of joint abilities and tasks, mechanisms of predicting own and others’ actions, and non-verbal communication through action. We will conclude by discussing ways in which different coordination mechanisms...
53 54 CULTURAL REPRESENTATION AND INTERCULTURAL ...
African Journals Online (AJOL)
user
2011-10-19
Oct 19, 2011 ... yet accepted the full impact of these intercultural interactions. Using some Nollywood films as primary data, ... what is presented in the. Ezinne Igwe. Cultural Representation and Intercultural Interaction: Nigeria. ..... is a tool for mass education and mass communication. Constantly exposing young girls to this ...
A representation for mammographic image processing.
Highnam, R; Brady, M; Shepstone, B
1996-03-01
Mammographic image analysis is typically performed using standard, general-purpose algorithms. We note the dangers of this approach and show that an alternative physics-model-based approach can be developed to calibrate the mammographic imaging process. This enables us to obtain, at each pixel, a quantitative measure of the breast tissue. The measure we use is h(int) and this represents the thickness of 'interesting' (non-fat) tissue between the pixel and the X-ray source. The thicknesses over the image constitute what we term the h(int) representation, and it can most usefully be regarded as a surface that conveys information about the anatomy of the breast. The representation allows image enhancement through removing the effects of degrading factors, and also effective image normalization since all changes in the image due to variations in the imaging conditions have been removed. Furthermore, the h(int) representation gives us a basis upon which to build object models and to reason about breast anatomy. We use this ability to choose features that are robust to breast compression and variations in breast composition. In this paper we describe the h(int) representation, show how it can be computed, and then illustrate how it can be applied to a variety of mammographic image processing tasks. The breast thickness turns out to be a key parameter in the computation of h(int), but it is not normally recorded. We show how the breast thickness can be estimated from an image, and examine the sensitivity of h(int) to this estimate. We then show how we can simulate any projective X-ray examination and can simulate the appearance of anatomical structures within the breast. We follow this with a comparison between the h(int) representation and conventional representations with respect to invariance to imaging conditions and the surrounding tissue. Initial results indicate that image analysis is far more robust when specific consideration is taken of the imaging process and
Assessment of representational competence in kinematics
Klein, P.; Müller, A.; Kuhn, J.
2017-06-01
A two-tier instrument for representational competence in the field of kinematics (KiRC) is presented, designed for a standard (1st year) calculus-based introductory mechanics course. It comprises 11 multiple choice (MC) and 7 multiple true-false (MTF) questions involving multiple representational formats, such as graphs, pictures, and formal (mathematical) expressions (1st tier). Furthermore, students express their answer confidence for selected items, providing additional information (2nd tier). Measurement characteristics of KiRC were assessed in a validation sample (pre- and post-test, N =83 and N =46 , respectively), including usefulness for measuring learning gain. Validity is checked by interviews and by benchmarking KiRC against related measures. Values for item difficulty, discrimination, and consistency are in the desired ranges; in particular, a good reliability was obtained (KR 20 =0.86 ). Confidence intervals were computed and a replication study yielded values within the latter. For practical and research purposes, KiRC as a diagnostic tool goes beyond related extant instruments both for the representational formats (e.g., mathematical expressions) and for the scope of content covered (e.g., choice of coordinate systems). Together with the satisfactory psychometric properties it appears a versatile and reliable tool for assessing students' representational competency in kinematics (and of its potential change). Confidence judgments add further information to the diagnostic potential of the test, in particular for representational misconceptions. Moreover, we present an analytic result for the question—arising from guessing correction or educational considerations—of how the total effect size (Cohen's d ) varies upon combination of two test components with known individual effect sizes, and then discuss the results in the case of KiRC (MC and MTF combination). The introduced method of test combination analysis can be applied to any test comprising
Probabilistic graphical model representation in phylogenetics.
Höhna, Sebastian; Heath, Tracy A; Boussau, Bastien; Landis, Michael J; Ronquist, Fredrik; Huelsenbeck, John P
2014-09-01
Recent years have seen a rapid expansion of the model space explored in statistical phylogenetics, emphasizing the need for new approaches to statistical model representation and software development. Clear communication and representation of the chosen model is crucial for: (i) reproducibility of an analysis, (ii) model development, and (iii) software design. Moreover, a unified, clear and understandable framework for model representation lowers the barrier for beginners and nonspecialists to grasp complex phylogenetic models, including their assumptions and parameter/variable dependencies. Graphical modeling is a unifying framework that has gained in popularity in the statistical literature in recent years. The core idea is to break complex models into conditionally independent distributions. The strength lies in the comprehensibility, flexibility, and adaptability of this formalism, and the large body of computational work based on it. Graphical models are well-suited to teach statistical models, to facilitate communication among phylogeneticists and in the development of generic software for simulation and statistical inference. Here, we provide an introduction to graphical models for phylogeneticists and extend the standard graphical model representation to the realm of phylogenetics. We introduce a new graphical model component, tree plates, to capture the changing structure of the subgraph corresponding to a phylogenetic tree. We describe a range of phylogenetic models using the graphical model framework and introduce modules to simplify the representation of standard components in large and complex models. Phylogenetic model graphs can be readily used in simulation, maximum likelihood inference, and Bayesian inference using, for example, Metropolis-Hastings or Gibbs sampling of the posterior distribution. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.
Assessment of representational competence in kinematics
Directory of Open Access Journals (Sweden)
P. Klein
2017-06-01
Full Text Available A two-tier instrument for representational competence in the field of kinematics (KiRC is presented, designed for a standard (1st year calculus-based introductory mechanics course. It comprises 11 multiple choice (MC and 7 multiple true-false (MTF questions involving multiple representational formats, such as graphs, pictures, and formal (mathematical expressions (1st tier. Furthermore, students express their answer confidence for selected items, providing additional information (2nd tier. Measurement characteristics of KiRC were assessed in a validation sample (pre- and post-test, N=83 and N=46, respectively, including usefulness for measuring learning gain. Validity is checked by interviews and by benchmarking KiRC against related measures. Values for item difficulty, discrimination, and consistency are in the desired ranges; in particular, a good reliability was obtained (KR20=0.86. Confidence intervals were computed and a replication study yielded values within the latter. For practical and research purposes, KiRC as a diagnostic tool goes beyond related extant instruments both for the representational formats (e.g., mathematical expressions and for the scope of content covered (e.g., choice of coordinate systems. Together with the satisfactory psychometric properties it appears a versatile and reliable tool for assessing students’ representational competency in kinematics (and of its potential change. Confidence judgments add further information to the diagnostic potential of the test, in particular for representational misconceptions. Moreover, we present an analytic result for the question—arising from guessing correction or educational considerations—of how the total effect size (Cohen’s d varies upon combination of two test components with known individual effect sizes, and then discuss the results in the case of KiRC (MC and MTF combination. The introduced method of test combination analysis can be applied to any test
Tamura, Tomoyuki
2014-01-01
In this paper we consider symmetric powers representation and exterior powers representation of finite groups, which generated by the representation which has finite dimension over the complex field. We calculate the multiplicity of irreducible component of two representations of some representation by using a character theory of representation and a pre-lambda-ring, for example, the regular representation.
Deng, Weihong; Hu, Jiani; Guo, Jun
2017-09-29
Collaborative representation methods, such as sparse subspace clustering (SSC) and sparse representation-based classification (SRC), have achieved great success in face clustering and classification by directly utilizing the training images as the dictionary bases. In this paper, we reveal that the superior performance of collaborative representation relies heavily on the sufficiently large class separability of the controlled face datasets such as Extended Yale B. On the uncontrolled or undersampled dataset, however, collaborative representation suffers from the misleading coefficients of the incorrect classes. To address this limitation, inspired by the success of linear discriminant analysis (LDA), we develop a superposed linear representation classifier (SLRC) to cast the recognition problem by representing the test image in term of a superposition of the class centroids and the shared intra-class differences. In spite of its simplicity and approximation, the new SLRC largely improves the generalization ability of collaborative representation, and competes well with more sophisticated dictionary learning techniques, on the experiments of AR and FRGC databases. Enforced with the sparsity constraint, SLRC achieves the state-of-the-art performance on FERET database using single sample per person.
Petersen, Jakob; Pollak, Eli
2015-12-14
One of the challenges facing on-the-fly ab initio semiclassical time evolution is the large expense needed to converge the computation. In this paper, we suggest that a significant saving in computational effort may be achieved by employing a semiclassical initial value representation (SCIVR) of the quantum propagator based on the Heisenberg interaction representation. We formulate and test numerically a modification and simplification of the previous semiclassical interaction representation of Shao and Makri [J. Chem. Phys. 113, 3681 (2000)]. The formulation is based on the wavefunction form of the semiclassical propagation instead of the operator form, and so is simpler and cheaper to implement. The semiclassical interaction representation has the advantage that the phase and prefactor vary relatively slowly as compared to the "standard" SCIVR methods. This improves its convergence properties significantly. Using a one-dimensional model system, the approximation is compared with Herman-Kluk's frozen Gaussian and Heller's thawed Gaussian approximations. The convergence properties of the interaction representation approach are shown to be favorable and indicate that the interaction representation is a viable way of incorporating on-the-fly force field information within a semiclassical framework.
An XML Representation for Crew Procedures
Simpson, Richard C.
2005-01-01
NASA ensures safe operation of complex systems through the use of formally-documented procedures, which encode the operational knowledge of the system as derived from system experts. Crew members use procedure documentation on the ground for training purposes and on-board space shuttle and space station to guide their activities. Investigators at JSC are developing a new representation for procedures that is content-based (as opposed to display-based). Instead of specifying how a procedure should look on the printed page, the content-based representation will identify the components of a procedure and (more importantly) how the components are related (e.g., how the activities within a procedure are sequenced; what resources need to be available for each activity). This approach will allow different sets of rules to be created for displaying procedures on a computer screen, on a hand-held personal digital assistant (PDA), verbally, or on a printed page, and will also allow intelligent reasoning processes to automatically interpret and use procedure definitions. During his NASA fellowship, Dr. Simpson examined how various industries represent procedures (also called business processes or workflows), in areas such as manufacturing, accounting, shipping, or customer service. A useful method for designing and evaluating workflow representation languages is by determining their ability to encode various workflow patterns, which depict abstract relationships between the components of a procedure removed from the context of a specific procedure or industry. Investigators have used this type of analysis to evaluate how well-suited existing workflow representation languages are for various industries based on the workflow patterns that commonly arise across industry-specific procedures. Based on this type of analysis, it is already clear that existing workflow representations capture discrete flow of control (i.e., when one activity should start and stop based on when other
On the mod p reduction of orthogonal representations
Serre, Jean-Pierre
2017-01-01
We show that the reduction mod p of an orthogonal linear representation is orthogonal, and we generalize this fact to representations of algebras with involution.The proofs make an essential use of the notion of " middle lattices ".
Augmentation Quotients for Real Representation Rings of Cyclic ...
Indian Academy of Sciences (India)
29
Augmentation Quotients for Real Representation Rings of Cyclic Groups. Article Type: Reseach Article. Keywords: cyclic group; real representation; augmentation ideal; augmentation quotient. Corresponding Author: Hang Liu, Ph.D. Shaanxi Normal University. Xi'an, Shaanxi CHINA. Corresponding Author Secondary.
Quasiprobability Representations of Quantum Mechanics with Minimal Negativity.
Zhu, Huangjun
2016-09-16
Quasiprobability representations, such as the Wigner function, play an important role in various research areas. The inevitable appearance of negativity in such representations is often regarded as a signature of nonclassicality, which has profound implications for quantum computation. However, little is known about the minimal negativity that is necessary in general quasiprobability representations. Here we focus on a natural class of quasiprobability representations that is distinguished by simplicity and economy. We introduce three measures of negativity concerning the representations of quantum states, unitary transformations, and quantum channels, respectively. Quite surprisingly, all three measures lead to the same representations with minimal negativity, which are in one-to-one correspondence with the elusive symmetric informationally complete measurements. In addition, most representations with minimal negativity are automatically covariant with respect to the Heisenberg-Weyl groups. Furthermore, our study reveals an interesting tradeoff between negativity and symmetry in quasiprobability representations.
Public understanding of visual representations of uncertainty in temperature forecasts
Tak, Susanne; Toet, Alexander; van Erp, Johannes Bernardus Fransiscus
Multiday weather forecasts often include graphical representations of uncertainty. However, visual representations of probabilistic events are often misinterpreted by the general public. Although various uncertainty visualizations are now in use, the parameters that determine their successful
Public understanding of visual representations of uncertainty in temperature forecasts
Tak, S.W.; Toet, A.; Erp, J.B.F. van
2015-01-01
Multiday weather forecasts often include graphical representations of uncertainty. However, visual representations of probabilistic events are often misinterpreted by the general public. Although various uncertainty visualizations are now in use, the parameters that determine their successful
Representation and integration of sociological knowledge using knowledge graphs
Popping, R; Strijker, [No Value
1997-01-01
The representation and integration of sociological knowledge using knowledge graphs, a specific kind of semantic network, is discussed. Knowledge it systematically searched this reveals. inconsistencies, reducing superfluous research and knowledge, and showing gaps in a theory. This representation
Linking neural and symbolic representation and processing of conceptual structures
van der Velde, Frank; Forth, Jamie; Nazareth, Deniece S.; Wiggins, Geraint A.
2017-01-01
We compare and discuss representations in two cognitive architectures aimed at representing and processing complex conceptual (sentence-like) structures. First is the Neural Blackboard Architecture (NBA), which aims to account for representation and processing of complex and combinatorial conceptual
Two visual working memory representations simultaneously control attention.
Chen, Yanan; Du, Feng
2017-07-21
It has been proposed that only one visual working memory (VWM) representation can be activated to influence perception directly, whereas other VWM representations are accessory items which have little influence on visual selection. The sole active VWM representation might reflect a fundamental bottleneck in the information processing of human beings. However, the present study showed that each of two VWM representations can capture attention and interfere with concurrent visual search. In addition, each of two VWM representations can interfere with concurrent visual search as much as can a single cued VWM representation. Moreover, when two memory-matching distractors appear in visual search, two VWM representations produce a larger memory-driven capture effect than a single memory-matching distractor. Thus, two VWM representations can simultaneously control attention.
Modes of Political Representation: Toward a New Typology
Andeweg, Rudy B.; Thomassen, Jacques J.A.
2005-01-01
The mandate-independence controversy still features prominently in studies of political representation even though the problems with its theoretical foundation and empirical operationalization have long been recognized. This article proposes an alternative typology of modes of representation. By
Social representations of alcohol and drug abuse among youth
Directory of Open Access Journals (Sweden)
E B Berezina
2010-09-01
Full Text Available The characteristics of representations of young people about alcohol and drug abuse are analyzed in the article. The authors reveal the key elements of the representations of alcoholism and drug abuse, discuss their differences and similarities.
Women’s political representation: parliamentary elections in 2012
National Research Council Canada - National Science Library
Ionela Băluţă
2013-01-01
...) in other European states. Moving from a diacronical and sincronical analysis of the statistical data indicating the political representation of women in post-communist Romania, the present paper aims to reflect on this under representation...
Two visual working memory representations simultaneously control attention
Chen, Yanan; Du, Feng
2017-01-01
It has been proposed that only one visual working memory (VWM) representation can be activated to influence perception directly, whereas other VWM representations are accessory items which have little influence on visual selection. The sole active VWM representation might reflect a fundamental bottleneck in the information processing of human beings. However, the present study showed that each of two VWM representations can capture attention and interfere with concurrent visual search. In add...
Body representation in patients after vascular brain injuries
Razmus, Magdalena
2017-01-01
Neuropsychological literature suggests that body representation is a multidimensional concept consisting of various types of representations. Previous studies have demonstrated dissociations between three types of body representation specified by the kind of data and processes, i.e. body schema, body structural description, and body semantics. The aim of the study was to describe the state of body representation in patients after vascular brain injuries and to provide evidence for the differe...
Gender Accountability and Political Representation in Local Government
V. Vijayalakshmi
2002-01-01
The representation of women in the institutions of local government has been facilitated through affirmative action, where one-third of the seats have been reserved for women. This raises issues related to the representation of gender interests and the constraints on such representation. The paper focuses on the complexities of political representation of women's interests. Lack of effective participation, multiplicity of identities, and the absence of the consolidation of gender specific con...
Elements of social representation theory incollaborative tagging systems
Patricia Zeni Marchiori; Andre Luiz Appel; Eduardo Michellotti Bettoni; Denise Fukumi Tsunoda; Frank Coelho de Alcântara
2014-01-01
This article discusses the information representation process based on the Moscovici's Social Representation Theory and domain analysis in Information Science. The aim was to identify mechanisms and constituent dimensions of social representation in collaborative tagging systems/social bookmarking systems. Scientific knowledge was defined as the object/phenomenon of representation in these systems; and the tag as the shareable structure of meaning that connects participants and resources. The...
Representation of Objective Situations in Preschool Children
Directory of Open Access Journals (Sweden)
N.Ye. Veraksa
2015-10-01
Full Text Available The paper focuses on the types of representations of objective situations, that is, situations which are defined independently of the subject, by certain external perceptible circumstances and social expectations or rules. The author distinguishes between three types of objective situations in which children act: normative, developing and ambiguous. For each of these types there is a corresponding form of representation: sign, dialectical and symbolic. Each form is a product of the subject's cognitive activity, at the core of which lie cognitive abilities — a system of culturally specific means and ways of using them. The paper outlines normative and stabilizing abilities, transformation abilities, and symbolic mediation abilities. They help categorize different objects and features, enable transformation of situations and provide possibilities for orientation in ambiguous situations
Moral transgressions corrupt neural representations of value.
Crockett, Molly J; Siegel, Jenifer Z; Kurth-Nelson, Zeb; Dayan, Peter; Dolan, Raymond J
2017-06-01
Moral systems universally prohibit harming others for personal gain. However, we know little about how such principles guide moral behavior. Using a task that assesses the financial cost participants ascribe to harming others versus themselves, we probed the relationship between moral behavior and neural representations of profit and pain. Most participants displayed moral preferences, placing a higher cost on harming others than themselves. Moral preferences correlated with neural responses to profit, where participants with stronger moral preferences had lower dorsal striatal responses to profit gained from harming others. Lateral prefrontal cortex encoded profit gained from harming others, but not self, and tracked the blameworthiness of harmful choices. Moral decisions also modulated functional connectivity between lateral prefrontal cortex and the profit-sensitive region of dorsal striatum. The findings suggest moral behavior in our task is linked to a neural devaluation of reward realized by a prefrontal modulation of striatal value representations.
Representations of the infinite symmetric group
Borodin, Alexei
2016-01-01
Representation theory of big groups is an important and quickly developing part of modern mathematics, giving rise to a variety of important applications in probability and mathematical physics. This book provides the first concise and self-contained introduction to the theory on the simplest yet very nontrivial example of the infinite symmetric group, focusing on its deep connections to probability, mathematical physics, and algebraic combinatorics. Following a discussion of the classical Thoma's theorem which describes the characters of the infinite symmetric group, the authors describe explicit constructions of an important class of representations, including both the irreducible and generalized ones. Complete with detailed proofs, as well as numerous examples and exercises which help to summarize recent developments in the field, this book will enable graduates to enhance their understanding of the topic, while also aiding lecturers and researchers in related areas.
Representations built from a true geographic database
DEFF Research Database (Denmark)
Bodum, Lars
2005-01-01
The development of a system for geovisualisation under the Centre for 3D GeoInformation at Aalborg University, Denmark, has exposed the need for a rethinking of the representation of virtual environments. Now that almost everything is possible (due to technological advances in computer graphics...... a representation based on geographic and geospatial principles. The system GRIFINOR, developed at 3DGI, Aalborg University, DK, is capable of creating this object-orientation and furthermore does this on top of a true Geographic database. A true Geographic database can be characterized as a database that can cover......) within the creation of Virtual Environments, what will be the next challenge within Urban simulation and modelling to overcome? It will certainly not be to create the models as real as possible or refine details in the texturing. The challenge will be to do a proper object-orientation and thereby secure...
Ergonomic risk: social representations of dental students
Directory of Open Access Journals (Sweden)
Luana Kelle Batista Moura
2014-01-01
Full Text Available Objective: To learn the social representations of ergonomic risk prepared by dental students. Methodology: This exploratory study, subsidized the Theory of Social Representations, with 64 dental students of an educational institution, by means of interviews. The data were processed in Alceste4.8 and lexical analysis done by the descending hierarchical classification. Results: In two categories: knowledge about exposure to ergonomic risk end attitude of students on preventing and treating injuries caused by repetitive motion. For students, the ergonomic risk is related to the attitude in the dental office. Conclusion: Prevention of ergonomic risk for dental students has not been incorporated as a set of necessary measures for their health and the patients, to prevent ergonomic hazards that can result in harm to the patient caused by work-related musculoskeletal disorder, which is reflected in a lower quality practice.
SUBJECTIVITY: SOCIAL REPRESENTATION OF THE FAMILY
Directory of Open Access Journals (Sweden)
Lourdete Rejane Ferro Zago
2013-09-01
Full Text Available The family, first family group of human beings, is the collective dimension of human existence and becomes responsible for the formation of the first social identity, as well as the constitution of subjectivity. Subjectivity is the inner world of each and every human being. This inner world is made up of emotions, feelings and thoughts. It is through this inner world that the individual relates to the social world, appointed by the outside world. This relationship follows the individual characteristics that mark the individual as unique, originated in shaping the individual, when they built the knowledge and beliefs. social representation as a form of knowledge, socially elaborated, shared with a practical purpose, contributing to the construction of a common reality to a social group. Is thus built up the social representation of the family.
The Media Representations of Police Image
Directory of Open Access Journals (Sweden)
Wayne W. L. Chan
2015-09-01
Full Text Available The Hong Kong Police Force has undergone one of its biggest challenges in the Occupy Movement that emerged in the last year. Despite the sheer complexity of the police roles, we know little about its representations in the media coverage, and even less about the extent to which the imagery impacts of police acting as peacekeepers would have been made upon the images of police acting as crime fighters. Against this background, this empirical research aims to investigate the police image and its relation to the police’s specifically categorized duties in Hong Kong. The content analysis of local newspaper accounts is used as the research method. It is found that there would be generally negative media representations of police in the order-maintenance work whereas the police images in the crime-fighting duties could still remain positive. The reasons for these findings and their implications for the conceptions of the police role are discussed.