This article describes a fast, easily implemented MILP algorithm which selects optimal boolean factors (called keys) for predicting the outcomes of Presidential elections in the United States. Results derived from the...
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This article describes a fast, easily implemented MILP algorithm which selects optimal boolean factors (called keys) for predicting the outcomes of Presidential elections in the United States. Results derived from the method support the validity and parsimony of the key-based election model offered by Lichtman and Keilis-Borok. (c) 2005 Elsevier B.V. All rights reserved.
Starting from rigid-plasticity, we develop variational formulations of first incremental elastoplasticity and then elastoplastodynamics. These formulations are discretized using standard finite element techniques whic...
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ISBN:
(纸本)9789609875011
Starting from rigid-plasticity, we develop variational formulations of first incremental elastoplasticity and then elastoplastodynamics. These formulations are discretized using standard finite element techniques which results in discrete optimization problems that can be solved efficiently by modern mathematical programming methods. Finally, the extension from associated perfect plasticity to general nonassociated and hardening plasticity is detailed.
Groundwater has always been considered to be a readily available source of water for domestic, agricultural and industrial use. The last decades, the lack of policymaking for the utilization of groundwater, has led to...
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Groundwater has always been considered to be a readily available source of water for domestic, agricultural and industrial use. The last decades, the lack of policymaking for the utilization of groundwater, has led to overexploitation in many areas. The cooperation of a wide range of scientists such as mathematicians, engineers, computer scientists, environmentalists and economists - operation researchers, have led to the design and construction of commercial computer programs concerned on water management and specifically on the optimal distribution of limited water resources using groundwater management models. These combined models, via simulation and optimization algorithms, result in one optimal solution through operations research and mathematical programming methods. The groundwater management models are based on the method of space superposition or the combination of space and time superposition for steady and unsteady state problems, respectively. In the present study, an algorithm is presented, which minimizes the dimension of the response matrix, concerning on two assumptions: the first is the added fixed cost which represents the water supply pumping well and the second is the removal of time superposition. The study area is a transboundary phreatic aquifer in Northern Greece, in the area of Eidomeni, a small Hellenic village just on the borderline with FYROM. The aquifer has a total area of 10,84 km(2), 26 operating - pumping wells, which the 9 of them consist control points of the hydraulic head. The number of the management periods is 12 months.
This paper presents a comparison of two heat exchanger network retrofit methods as they are applied to crude units: the well-known and widely used Pinch Design Method (PDM) and a recently developed Heat Integration Tr...
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This paper presents a comparison of two heat exchanger network retrofit methods as they are applied to crude units: the well-known and widely used Pinch Design Method (PDM) and a recently developed Heat Integration Transportation Model (HIT), a recently developed mathematical programming-based MILP model [Nguyen et al. Ind. Chem, Eng. Res. 2010, 49, 13]. We show that the three-step procedure (targeting, design, and evolution) used by Pinch Technology renders solutions with excessive and unrealistic splitting of streams as well as visibly less profit compared to the results of HIT.
Graph mining methods enumerate frequently appearing subgraph patterns, which can be used as features for subsequent classification or regression. However, frequent patterns are not necessarily informative for the give...
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Graph mining methods enumerate frequently appearing subgraph patterns, which can be used as features for subsequent classification or regression. However, frequent patterns are not necessarily informative for the given learning problem. We propose a mathematical programming boosting method (gBoost) that progressively collects informative patterns. Compared to AdaBoost, gBoost can build the prediction rule with fewer iterations. To apply the boosting method to graph data, a branch-and-bound pattern search algorithm is developed based on the DFS code tree. The constructed search space is reused in later iterations to minimize the computation time. Our method can learn more efficiently than the simpler method based on frequent substructure mining, because the output labels are used as an extra information source for pruning the search space. Furthermore, by engineering the mathematical program, a wide range of machine learning problems can be solved without modifying the pattern search algorithm.
The optimal placement of turbines in a wind farm is critical to the maximization of power production. In this paper, we develop a new mathematical programming approach for wind farm layout optimization. We use Jensen&...
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The optimal placement of turbines in a wind farm is critical to the maximization of power production. In this paper, we develop a new mathematical programming approach for wind farm layout optimization. We use Jensen's wake decay model to represent multi-turbine wake effects. We develop mixed integer linear and quadratic optimization formulations and apply them to several example layout cases in the literature. Compared to previous approaches, our models produce layouts that tend to be more symmetric and that generate slightly more power. Our formulations solve quickly, allowing a decision maker to efficiently explore the impact of different turbine densities in a wind farm. (C) 2013 Elsevier Ltd. All rights reserved.
The generation of a good layout is an important stage in the design of a new plant or the retrofit of an existing facility. Layout decisions affect piping, electrics, instrumentation and therefore have a great impact ...
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The generation of a good layout is an important stage in the design of a new plant or the retrofit of an existing facility. Layout decisions affect piping, electrics, instrumentation and therefore have a great impact on the total plant cost. Moreover, layout has a large impact on the safety, operability and maintainability of any chemical plant. This paper presents a general mathematical programming approach for addressing the problem of allocating items of equipment in a given two or three dimensional space. The problem is formulated as a mixed integer linear programming model where equipment of various sizes and geometries are taken into account. The objective function to be minimized accounts for the total transport, connection, land and floor construction cost. This optimization procedure results in the coordinates of each unit (location), the total piping length, and the land occupied. Three case studies are presented to illustrate the applicability of the proposed approach. (C) 1999 Elsevier Science Ltd. All rights reserved.
In 1952, Radstrom proved a lemma which states that the Hausdorff distance between two convex sets A and B equals the Hausdorff distance between the translated sets A + X and B + X , provided X is bounded. This paper e...
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In 1952, Radstrom proved a lemma which states that the Hausdorff distance between two convex sets A and B equals the Hausdorff distance between the translated sets A + X and B + X , provided X is bounded. This paper extends this result to more general types of translations. The theory developed is then applied to the problem of establishing upper bounds on the Hausdorff distance between two unbounded convex feasible regions, one of which is obtained by perturbing the data defining the other.
Classical limit analysis of structures by the statical approach computationally means maximization of a load multiplier under equilibrium and yield condition constraints, namely convex mathematical programming. In ela...
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Classical limit analysis of structures by the statical approach computationally means maximization of a load multiplier under equilibrium and yield condition constraints, namely convex mathematical programming. In elastoplasticity, generalizations of limit analysis had been proposed in order to achieve, still by load factor constrained optimization, the safety factor with respect to plastic collapse. This paper presents similar generalization in two-phase poroelastoplasticity. A method is here developed (and validated by numerical application to a masonry dam) apt to assess the safety factor of a structure interpretable as a poroplastic system, with respect to both plastic collapse and critical thresholds on deformations, by solving a nonconvex nonsmooth constrained optimization problem usually referred to in the literature as "mathematical program under equilibrium constraints". Piece-wise linearization of yield surfaces and reduction of yield planes by a "sifting" procedure are adopted to reduce computing efforts.
The purpose of this paper is to use mathematical programming, including linear programming, dynamic programming, integer programming and goal programming to verify rule-based knowledge. We investigate both domain inde...
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The purpose of this paper is to use mathematical programming, including linear programming, dynamic programming, integer programming and goal programming to verify rule-based knowledge. We investigate both domain independent verification, exploiting the general structure of rules, and domain dependent verification, exploiting structure in the domain. mathematical programming software is readily available and is very efficient. As a result, verification using mathematical programming can be very efficient at finding errors. mathematical programming can be used to more than just find errors in knowledge representation. Once an error has been found, mathematical programming can be used to ''recommend'' an alternative. The recommendation can take into account the previous verified knowledge to mitigate the potential introduction of redundant knowledge and to help guide the choice process. Normally the development of recommendations to fix errors has been ignored in the verification literature, and treated as a separate knowledge acquisition task. Accordingly, this paper also extends the verification effort by providing a recommendation on how to fix errors.
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