102,916 research outputs found
Attention and Performance: The Benefit of Optimal Attentional Focus Under Pressure
No full textLand WM, Tenenbaum G. Attention and Performance: The Benefit of Optimal Attentional Focus Under Pressure. Presented at the International Society of SportPsychology (ISSP), Marrakech, Morokko
Action theory approach to applied sport psychology
No full textSchack T, Hackfort D. Action theory approach to applied sport psychology. In: Tenenbaum G, Eklund RC, eds. Handbook of Sport Psychology. 3rd ed. Hoboken, NJ, USA: John Wiley & Sons; 2007: 332-351
Small Gál sums and applications
No full textIn recent years, maximizing Gál sums regained interest due to a firm link with large values of (Formula presented.) -functions. In the present paper, we initiate an investigation of small sums of Gál type, with respect to the (Formula presented.) -norm. We also consider the intertwined question of minimizing weighted versions of the usual multiplicative energy. We apply our estimates to: (i) a logarithmic refinement of Burgess' bound on character sums, improving previous results of Kerr, Shparlinski and Yau; (ii) an improvement on earlier lower bounds by Louboutin and the second author for the number of nonvanishing theta functions associated to Dirichlet characters; and (iii) new lower bounds for low moments of character sums
Facilitation of Automaticity: Sport Relevant vs. Non-Relevant Secondary Tasks
No full textLand WM, Tenenbaum G. Facilitation of Automaticity: Sport Relevant vs. Non-Relevant Secondary Tasks. Presented at the North American Society for the Psychology of Sport and Physical Activity (NASPSPA), San Diego, California
Attention and Movement Variability: Facilitation of Compensatory Mechanisms Under Optimal Attentional Focus
No full textLand WM, Tenenbaum G. Attention and Movement Variability: Facilitation of Compensatory Mechanisms Under Optimal Attentional Focus. Presented at the North American Society for the Psychology of Sport and Physical Activity (NASPSPA), Niagara Fall, Ontario, Canada
Ordered and chaotic dynamics of collective variables in a butane molecule
No full textWe have simulated the dynamics of a butane molecule and computed the time evolution of two sets of collective variables: (a) internal variables (stretchings, bendings, and dihedral angle) and (b) variables derived from a principal component analysis (PCA). We have characterized each collective variable by a coherence time, the time needed to develop its chaotic behavior. The coherence times diminish significantly when the temperature is raised into and above the range where conformational transitions of the dihedral angle set in. Below this transition region the coherence times of some variables reach hundreds of picoseconds (principal components) or even nanoseconds (internal variables); moreover, there are large differences among variables, as their coherence time can be much larger or much smaller than the Lyapunov time of the whole molecule. This result reflects the prediction of Nekhoroshev’s theorem. Crossing the transition region, the coherence times of both sets of variables drop to few picoseconds, and the differences among variables diminish. Still, the coordinates and velocities characterized by the largest fluctuations in the PCA appear to be also the most coherent ones, below and above the transition region
Mental Representation in Action: A Cognitive Architecture Approach
No full textSchack T. Mental Representation in Action: A Cognitive Architecture Approach. In: Tenenbaum G, Eklund RC, eds. Handbook of Sport Psychology. Bd. 2. 4th ed. Hoboken, NJ: Wiley; 2020: 513-534
Locality Sensitive Hashing for Efficient Similar Polygon Retrieval
No full textLocality Sensitive Hashing (LSH) is an effective method of indexing a set of items to support efficient nearest neighbors queries in high-dimensional spaces. The basic idea of LSH is that similar items should produce hash collisions with higher probability than dissimilar items.
We study LSH for (not necessarily convex) polygons, and use it to give efficient data structures for similar shape retrieval. Arkin et al. [Arkin et al., 1991] represent polygons by their "turning function" - a function which follows the angle between the polygon’s tangent and the x-axis while traversing the perimeter of the polygon. They define the distance between polygons to be variations of the L_p (for p = 1,2) distance between their turning functions. This metric is invariant under translation, rotation and scaling (and the selection of the initial point on the perimeter) and therefore models well the intuitive notion of shape resemblance.
We develop and analyze LSH near neighbor data structures for several variations of the L_p distance for functions (for p = 1,2). By applying our schemes to the turning functions of a collection of polygons we obtain efficient near neighbor LSH-based structures for polygons. To tune our structures to turning functions of polygons, we prove some new properties of these turning functions that may be of independent interest.
As part of our analysis, we address the following problem which is of independent interest. Find the vertical translation of a function f that is closest in L₁ distance to a function g. We prove tight bounds on the approximation guarantee obtained by the translation which is equal to the difference between the averages of g and f
Canonical ensemble and nonequilibrium states by molecular dynamics
No full textWe present a new technique to simulate the contact of a molecular dynamics system with a thermal wall. A canonical ensemble is obtained, and its statistical and thermodynamic fluctuations are studied. The values of the specific heat found by simulation agree with the experimental data. By means of thermal walls at different temperatures, thermal gradients are obtained. The values of the thermal conductivity are consistent with the experimental data. © 1980 Plenum Publishing Corporation
Psychological factors in technical preparation
No full textSchack T, Bar-Eli M. Psychological factors in technical preparation. In: Blumenstein B, Lidor R, Tenenbaum G, eds. Psychology of sport training. Oxford, UK: Meyer & Meyer Sport; 2007: 62-103
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