Current Issue : April - June Volume : 2013 Issue Number : 2 Articles : 4 Articles
The minimax algorithm, also called the negamax algorithm, remains today the\r\nmost widely used search technique for two-player perfect-information games. However,\r\nminimaxing has been shown to be susceptible to game tree pathology, a paradoxical situation\r\nin which the accuracy of the search can decrease as the height of the tree increases. Alth�¨oferâ��s\r\nalternative minimax algorithm has been proven to be invulnerable to pathology. However,\r\nit has not been clear whether alpha-beta pruning, a crucial component of practical game\r\nprograms, could be applied in the context of Alh�¨oferâ��s algorithm. In this brief paper, we\r\nshow how alpha-beta pruning can be adapted to Alth�¨oferâ��s algorithm....
For test-sheet composition systems, it is important to adaptively compose test sheets with\r\ndiverse conceptual scopes, discrimination and difficulty degrees to meet various assessment\r\nrequirements during real learning situations. Computation time and item exposure rate also\r\ninfluence performance and item bank security. Therefore, this study proposes an Adaptive Test\r\nSheet Generation ATSG mechanism, where a Candidate Item Selection Strategy adaptively\r\ndetermines candidate test items and conceptual granularities according to desired conceptual\r\nscopes, and an Aggregate Objective Function applies Genetic Algorithm GA to figure out the\r\napproximate solution of mixed integer programming problem for the test-sheet composition.\r\nExperimental results show that the ATSG mechanism can efficiently, precisely generate test\r\nsheets to meet the various assessment requirements than existing ones. Furthermore, according\r\nto experimental finding, Fractal Time Series approach can be applied to analyze the self-similarity\r\ncharacteristics of GA�s fitness scores for improving the quality of the test-sheet composition in the\r\nnear future....
In this paper we present the PHOCS-2 algorithm, which extracts a ââ?¬Å?Predicted\r\nHierarchy Of ClassifierSââ?¬Â. The extracted hierarchy helps us to enhance performance of\r\nflat classification. Nodes in the hierarchy contain classifiers. Each intermediate node\r\ncorresponds to a set of classes and each leaf node corresponds to a single class. In the\r\nPHOCS-2 we make estimation for each node and achieve more precise computation of false\r\npositives, true positives and false negatives. Stopping criteria are based on the results of the\r\nflat classification. The proposed algorithm is validated against nine datasets....
Regularized Heaviside and Dirac delta function are used in several fields of\r\ncomputational physics and mechanics. Hence the issue of the quadrature of integrals\r\nof discontinuous and singular functions arises. In order to avoid ad-hoc quadrature\r\nprocedures, regularization of the discontinuous and the singular fields is often carried out.\r\nIn particular, weight functions of the signed distance with respect to the discontinuity\r\ninterface are exploited. Tornberg and Engquist (Journal of Scientific Computing, 2003,\r\n19: 527ââ?¬â??552) proved that the use of compact support weight function is not suitable\r\nbecause it leads to errors that do not vanish for decreasing mesh size. They proposed\r\nthe adoption of non-compact support weight functions. In the present contribution, the\r\nrelationship between the Fourier transform of the weight functions and the accuracy of the\r\nregularization procedure is exploited. The proposed regularized approach was implemented\r\nin the eXtended Finite Element Method. As a three-dimensional example, we study a slender\r\nsolid characterized by an inclined interface across which the displacement is discontinuous.\r\nThe accuracy is evaluated for varying position of the discontinuity interfaces with respect\r\nto the underlying mesh. A procedure for the choice of the regularization parameters\r\nis proposed....
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