There are usually many sources for the supply of raw material to a pulp or paper mill in Sweden. Optimization of this supply is therefore a challenging task, and can only be managed properly if all aspects of risk are...
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There are usually many sources for the supply of raw material to a pulp or paper mill in Sweden. Optimization of this supply is therefore a challenging task, and can only be managed properly if all aspects of risk are considered. In our study, these risks are related to when the weather reduces the load-bearing capacity of the ground or the roads. A stochastic and a deterministic model have been formulated, and they have been solved with mixed-integer quadratic programming and tested with data from a Swedish forest company. The results of this study show that the option value is greater than zero and that both the optimal policy and the option value change whenever the storage cost is altered. This shows that the optimal planning policy obtained from the stochastic model differs from the solution of the deterministic model.
In this paper optimization of N-removal in sewage treatment is accomplished by exploiting mixed logical dynamic method(MLD). According to simplifying activated sludge process No.1 model (ASM1), N-removal dynamic model...
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ISBN:
(纸本)0780378652
In this paper optimization of N-removal in sewage treatment is accomplished by exploiting mixed logical dynamic method(MLD). According to simplifying activated sludge process No.1 model (ASM1), N-removal dynamic models in continuously mixed, continuously fed activated sludge process (ASP) are established by employing expert experience about activated sludge process. Then predictive control approach is applied to optimal control of this process. The simulation results show that it can cover the relative expert experiences more widely by applying MLD to modeling and control of activated sludge process. These expert experiences combined with continuous variable model make model more precise and can get better effect of optimization and control. This study provides a new approach to the research of sewage treatment.
We propose a state-smoothing algorithm for hybrid systems based on moving-horizon estimation (MHE) by exploiting the equivalence between hybrid systems modeled in the mixed logic dynamical form and piecewise affine sy...
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We propose a state-smoothing algorithm for hybrid systems based on moving-horizon estimation (MHE) by exploiting the equivalence between hybrid systems modeled in the mixed logic dynamical form and piecewise affine systems. We provide sufficient conditions on the time horizon and the penalties on the state at the beginning of the estimation horizon to guarantee asymptotic convergence of the MHE scheme. Moreover, we propose two practical algorithms for the computation of penalties that allow to implement MHE by solving a mixed-integerquadratic program.
In this paper, by exploiting the equivalence between hybrid systems modeled in the mixed Logic Dynamical form and Piece-Wise Affine systems, we propose a state smoothing algorithm based on Moving Horizon Estimation (M...
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ISBN:
(纸本)0780355202
In this paper, by exploiting the equivalence between hybrid systems modeled in the mixed Logic Dynamical form and Piece-Wise Affine systems, we propose a state smoothing algorithm based on Moving Horizon Estimation (MHE). We provide sufficient conditions on the time horizon and the initial penalties to guarantee asymptotic convergence of the MHE scheme. Moreover we propose an algorithm for the computation of the initial penalties that allows to implement MHE by solving mixed-integerquadratic Programs.
In a recent paper [6] we suggested an algorithm for solving complicated mixed-integerquadratic programs, based on an equivalent formulation that employs a nonsingular transformation of variables. The objectives of th...
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In a recent paper [6] we suggested an algorithm for solving complicated mixed-integerquadratic programs, based on an equivalent formulation that employs a nonsingular transformation of variables. The objectives of the present paper are two. First, to present an improved version of this algorithm, which reduces substantially its computational requirements; second, to report on the results of a computational study with the revised algorithm.
The uncapacitated plant location problem under uncertainty is formulated in a mean-variance framework with prices in various markets correlated according to their response to a common random factor. This formulation ...
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The uncapacitated plant location problem under uncertainty is formulated in a mean-variance framework with prices in various markets correlated according to their response to a common random factor. This formulation leads to a mixed-integer quadratic programming problem. However, for a given integer solution, the problem lends itself to a very simple solution procedure. Because of the simplicity of this algorithm, reasonably large problems should be solvable through the use of existing branch-and-bound techniques. Except for the sorting procedure, the computation time increases at most linearly with the size of the nodal subproblem. Dominance holds for the plant location problem addressed here, allowing some relaxation of Jucker and Carlson's (1976) independence assumption.
This paper considers mixed-integerquadratic programs in which the objective function is quadratic in the integer and in the continuous variables, and the constraints are linear in the variables of both types. The gen...
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This paper considers mixed-integerquadratic programs in which the objective function is quadratic in the integer and in the continuous variables, and the constraints are linear in the variables of both types. The generalized Benders' decomposition is a suitable approach for solving such programs. However, the program does not become more tractable if this method is used, since Benders' cuts are quadratic in the integer variables. A new equivalent formulation that renders the program tractable is developed, under which the dual objective function is linear in the integer variables and the dual constraint set is independent of these variables. Benders' cuts that are derived from the new formulation are linear in the integer variables, and the original problem is decomposed into a series of integer linear master problems and standard quadratic subproblems. The new formulation does not introduce new primary variables or new constraints into the computational steps of the decomposition algorithm.
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