We address a particular class of bilevel linear programming problems in which all the variables are discrete. The main computational complexities are analyzed and two enhanced exact algorithms are proposed. The ration...
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We address a particular class of bilevel linear programming problems in which all the variables are discrete. The main computational complexities are analyzed and two enhanced exact algorithms are proposed. The rationale behind these two algorithms is described and a modified version is presented for both. A common test bed is used to assess their computational efficiency along with a comparison with an existing benchmark algorithm.
Verifying a rational response is the most crucial step in searching for an optimal solution in bilevel linear programming. Such verification is even difficult in a model with ambiguous objective function of the follow...
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Verifying a rational response is the most crucial step in searching for an optimal solution in bilevel linear programming. Such verification is even difficult in a model with ambiguous objective function of the follower who reacts rationally to a leader's decision. In our model, we assume that the ambiguous coefficient vector of follower lies in a convex polytope and we formulate bilevel linear programming with the ambiguous objective function of the follower as a special three-level programming problem. We use the k-th best method that sequentially enumerates a solution and examine whether it is the best of all possible reactions. The optimality test process over possible reactions in lower-level problems usually encounters degenerate bases that become obstacles to verifying the optimality of an enumerated solution efficiently. To accelerate optimality verification, we propose search strategies and the evaluation of basic possible reactions adjacent to a degenerate basic solution. We introduce these methods in both local and global optimality testing, confirming the effectiveness of our proposed methods in numerical experiments.
This paper presents an improved multiple objective particle swarm optimization (MOPSO) algorithm to solve bilevel linear programming problems with multiple objective functions at the upper level. The algorithm aims to...
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This paper presents an improved multiple objective particle swarm optimization (MOPSO) algorithm to solve bilevel linear programming problems with multiple objective functions at the upper level. The algorithm aims to produce a good approximation of the entire Pareto front of the problem. We have previously designed a MOPSO algorithm for the same class of problems, in which several techniques for the global best selection were tested, including a new one. The algorithm revealed a good convergence towards the Pareto front but the diversity of the solutions was a drawback. The algorithm we propose herein uses a hybrid strategy for the global best selection and an adaptive mutation operator. The incorporation of these mechanisms led to an improved algorithm, which also showed better overall performance than considering alternative options usually employed in MOPSO algorithms. The algorithm and computational results are presented. (C) 2014 Elsevier Inc. All rights reserved.
This paper presents an approach for solving bilevel linear programming problems (BLPP). It is based on the result that an optimal solution to the BLPP is reachable at an extreme point of the underlying region. Consequ...
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This paper presents an approach for solving bilevel linear programming problems (BLPP). It is based on the result that an optimal solution to the BLPP is reachable at an extreme point of the underlying region. Consequently, we develop a pivot technique to find the global optimal solution on an expanded tableau that represents the data of the BLPP. The pivot technique allows to rank in increasing order the outer level objective function value until a value is reached with a corresponding extreme point feasible for the BLPP. This solution is then the required global solution. Numerical examples are provided. Solutions obtained through our algorithm to some problems available in the literature show that these problems were until now wrongly solved.
One of the main aims of the Rural Development Plan under the EU Common Agricultural Policy is the protection of nitrate sensitive areas through agri-environmental schemes. This paper presents a mathematical programmin...
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One of the main aims of the Rural Development Plan under the EU Common Agricultural Policy is the protection of nitrate sensitive areas through agri-environmental schemes. This paper presents a mathematical programming model for farm planning in agricultural areas that are sensitive to nitrates. A bilevel linear programming (BLP) model is developed, that can achieve the optimal farm production plan assuming two conflicting goals: the maximisation of farm gross margin and the minimisation of fertilisers' use. The first goal is pursued by farmers, and comprises the first level of BLP. The second goal is pursued by society, through the government, and comprises the second level of BLP. The model is applied to an agricultural area in Northern Greece, which belongs to the nitrate sensitive areas scheme of the Greek Rural Development Plan 2007-2013. The model is further used to simulate the impacts of the measure under two scenarios proposed for farms located in nitrate sensitive areas. The result shows that the model can achieve the two goals set by increasing gross margin and reducing fertilisers use.
For the optimum price problem of charging for effluent, this paper analyzes the optimal Pigovian Tax and the serious information asymmetry problem existing in the application process of optimal Pigovian Tax, which is ...
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For the optimum price problem of charging for effluent, this paper analyzes the optimal Pigovian Tax and the serious information asymmetry problem existing in the application process of optimal Pigovian Tax, which is predominant in theory. Then the bilevel system optimizing decision-making theory is applied to give bilevel linear programming decision-making model of charging for effluent, in which the government (environmental protection agency) acts as the upper level decision-making unit and the polluting enterprises act as the lower level decision-making unit. To some extent, the model avoids the serious information asymmetry between the government and the polluting enterprises on charging for effluent.
linear mixed 0-1 integer programming problems may be reformulated as equivalent continuous bilevel linear programming (BLP) problems. We exploit these equivalences to transpose the concept of mixed 0-1 Gomory cuts to ...
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linear mixed 0-1 integer programming problems may be reformulated as equivalent continuous bilevel linear programming (BLP) problems. We exploit these equivalences to transpose the concept of mixed 0-1 Gomory cuts to BLP. The first phase of our new algorithm generates Gomory-like cuts. The second phase consists of a branch-and-bound procedure to ensure finite termination with a global optimal solution. Different features of the algorithm, in particular, the cut selection and branching criteria are studied in details. We propose also a set of algorithmic tests and procedures to improve the method. Finally, we illustrate the performance through numerical experiments. Our algorithm outperforms pure branch-and-bound when tested on a series of randomly generated problems.
bilevel linear programming, which consists of the objective functions of the upper level and lower level, is a useful tool for modeling decentralized decision problems. Various methods are proposed for solving this pr...
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bilevel linear programming, which consists of the objective functions of the upper level and lower level, is a useful tool for modeling decentralized decision problems. Various methods are proposed for solving this problem. Of all the algorithms, the ge- netic algorithm is an alternative to conventional approaches to find the solution of the bilevel linear programming. In this paper, we describe an adaptive genetic algorithm for solving the bilevel linear programming problem to overcome the difficulty of determining the probabilities of crossover and mutation. In addition, some techniques are adopted not only to deal with the difficulty that most of the chromosomes maybe infeasible in solving constrained optimization problem with genetic algorithm but also to improve the efficiency of the algorithm. The performance of this proposed algorithm is illustrated by the examples from references.
We present an algorithm for solving bilevellinear programs that uses simplex pivots on an expanded tableau. The algorithm uses the relationship between multiple objective linear programs and bilevellinear programs a...
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We present an algorithm for solving bilevellinear programs that uses simplex pivots on an expanded tableau. The algorithm uses the relationship between multiple objective linear programs and bilevellinear programs along with results for minimizing a linear objective over the efficient set for a multiple objective problem. Results in multiple objective programming needed are presented. We report computational experience demonstrating that this approach is more effective than a standard branch-and-bound algorithm when the number of leader variables is small.
The value-at-risk is an important risk measure that has been used extensively in recent years in portfolio selection and in risk analysis. This problem, with its known bilevellinear program, is reformulated as a poly...
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The value-at-risk is an important risk measure that has been used extensively in recent years in portfolio selection and in risk analysis. This problem, with its known bilevellinear program, is reformulated as a polyhedral DC program with the help of exact penalty techniques in DC programming and solved by DCA. To check globality of computed solutions, a global method combining the local algorithm DCA with a well adapted branch- and- bound algorithm is investigated. An illustrative example and numerical simulations are reported, which show the robustness, the globality and the efficiency of DCA.
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