Expert systems in government

Leach, Stephen P.; Kandel, Abraham

doi:10.1145/152535.152536

Cited by 4 publications

(2 citation statements)

References 22 publications

(21 reference statements)

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“…The functional form is 1 / 2 ∑ j V j (1 + cos(jω + φ)), where V j is the amplitude (one-half the barrier height), φ is the phase factor which determines the location of the minima, and ω is the torsional angle. The diffusion equation solution for torsional potentials is of the form 1 …”

Section: Appendix Amentioning

confidence: 99%

“…Selected methods from each of these four categories have been extensively reviewed. 1,2 Deterministic methods include space covering techniques such as branch-and-bound search, 3 systematic search methods, 4 and generalized descent methods. 5 These methods are useful for small problems or for larger systems with well-established constraints, but will in general fail for large problems due to the exponential increase in the size of the space to be searched.…”

Section: Introductionmentioning

confidence: 99%

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Analysis and Application of Potential Energy Smoothing and Search Methods for Global Optimization

1998

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Global energy optimization of a molecular system is difficult due to the well-known "multiple minimum" problem. The rugged potential energy surface (PES) characteristic of multidimensional systems can be transformed reversibly using potential smoothing to generate a new surface that is easier to search for favorable configurations. The diffusion equation method (DEM) is one example of a potential smoothing algorithm. Potential smoothing as implemented in DEM is intuitively appealing and has certain appropriate statistical mechanical properties, but often fails to identify the global minimum even for relatively small problems. In the present paper, extensions to DEM capable of correcting its empirical behavior are systematically investigated. Two types of local search (LS) procedures are applied during the reversing schedule from the smooth deformed PES to the undeformed surface. Changes needed to generate smoothable versions of standard molecular mechanics force fields such as AMBER/OPLS and MM2 are also described. The resulting methods are applied in an attempt to determine the global energy minimum for a variety of systems in different coordinate representations. The problems studied include argon clusters, cycloheptadecane, capped polyalanine, and the docking of R-helices. Depending on the specific problem, potential smoothing and search (PSS) is performed in Cartesian, torsional, or rigid body space. For example, PSS finds a very low energy structure for cycloheptadecane with much greater efficiency than a search restricted to the undeformed potential surface. It is shown that potential smoothing is characterized by three salient features. As the level of smoothing is increased, unique minima merge into a common basin, crossings can occur in the relative energies of a pair of minima, and the spatial locations of minima are shifted due to the averaging effects of smoothing. Local search procedures improve the ability of smoothing methods to locate global minima because they facilitate the post facto correction of errors due to energy crossings that may have occurred at higher levels of smoothing. PSS methods should serve as useful tools for global energy optimization on a variety of difficult problems of practical interest.

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Section: Appendix Amentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis and Application of Potential Energy Smoothing and Search Methods for Global Optimization

1998

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Improving Electoral Districting through Geographic Information Systems

Hor¹,

Peng²

2015

Proceedings of the 2015 International Conference on Computer Science and Intelligent Communication

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Abstract-In this paper, we present an approach that can solve the electoral districting problems by integrating the technologies of dynamics programming, computational geometry as well as the geographic information systems. A quantitative measurement to evaluate the shape of the districting results is also presented. We have applied these methods to Changhua County in Taiwan and obtained more than hundred thousands of feasible solutions.

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Application of Computational Geometry on Multi-region Electoral Districting

Hor¹,

Hung²,

Hung³

et al. 2013

Proceedings of the 2013 International Conference on the Modern Development of Humanities and Social Science

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Different electoral districting affects the election results. The spirit of democracy is worthwhile that the election system must be fair and square and legitimately practices without the occurrence of that the political party and candidate taking advantages on the electoral districting inducing controversy over manipulating the election strategy. In this study, we developed a computational geometry based partitioning algorithm to solve the multi-region electoral districting problems. The algorithm uses the Geographic Information System as well as the dynamic programming techniques and solves the multi-region districting problems by recursively applying the two-partitioning algorithm. The problem regarding to the huge feasible solutions can be reduced substantially by introducing the concept of "indivisible regions". The contiguity test and the compactness test can be done through the knowledge of computational geometry. The method is implemented on a local county to illustrate the entire mechanism and obtained feasible solutions for further evaluation and analysis. We also used the historical voting results to evaluate our districting results and compared with the results released by CEC (Central Election Commission). The analyses show that our methods can solve the multi-region electoral districting problems successfully and effectively.

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Expert systems in government

Cited by 4 publications

References 22 publications

Analysis and Application of Potential Energy Smoothing and Search Methods for Global Optimization

Analysis and Application of Potential Energy Smoothing and Search Methods for Global Optimization

Improving Electoral Districting through Geographic Information Systems

Application of Computational Geometry on Multi-region Electoral Districting

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