The facility location problem described in this paper comes from an industrial application in the slaughterhouse industry of Norway. Investigations show that the slaughterhouse industry experiences economies of scale ...
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The facility location problem described in this paper comes from an industrial application in the slaughterhouse industry of Norway. Investigations show that the slaughterhouse industry experiences economies of scale in the production facilities. We examine a location-allocation problem focusing on the location of slaughterhouses, their size and the allocation of animals in the different farming districts to these slaughterhouses. The model is general and has applications within other industries that experience economies of scale. We present an approach based on linearization of the facility costs and Lagrangean relaxation. We also develop a greedy heuristic to find upper bounds. We use the method to solve a problem instance for the Norwegian Meat Co-operative and compare our results to previous results achieved using standard branch-and-bound in commercial software. (c) 2005 Elsevier B.V. All rights reserved.
Incomplete data, due to missing observations or interval measurement of variables, usually cause parameters of interest in applications to be unidentified except under untestable and often controversial assumptions. H...
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Incomplete data, due to missing observations or interval measurement of variables, usually cause parameters of interest in applications to be unidentified except under untestable and often controversial assumptions. However, it is often possible to identify sharp bounds on parameters without making untestable assumptions about the process through which data become incomplete. The bounds contain all logically possible values of the parameters and can be estimated consistently by replacing the population distribution of the data with the empirical distribution. This is straightforward in some circumstances but computationally burdensome in others. This paper describes the general problem and presents an empirical illustration. (c) 2005 Elsevier B.V. All rights reserved.
作者:
Chen, YZChen, LShanghai Univ
Dept Precis Mech Engn Sch Mechatron Engn & Automat Shanghai 200444 Peoples R China
Product planning is one of four important processes in new product development (NPD) using quality function deployment (QFD). In order to model the process of product planning, the first problem to be solved is how to...
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Product planning is one of four important processes in new product development (NPD) using quality function deployment (QFD). In order to model the process of product planning, the first problem to be solved is how to incorporate both qualitative and quantitative information regarding relationships between customer requirements and engineering characteristics, as well as among engineering characteristics, into the problem formulation. The inherent fuzziness of functional relationships in product planning makes the use of possibilistic regression justifiable. However, when linearprogramming in possibilistic regression analysis is used, some coefficients tend to become crisp because of the characteristic of linearprogramming. To tackle the problem, a non-linear programming based possibilistic regression approach is proposed, by which more diverse spread coefficients can be obtained than from a linearprogramming approach. An emulsification dynamite packing-machine design is used to illustrate the performance of the proposed approach.
The strategic importance of vendor evaluation is well established in the purchasing literature. Several evaluation methodologies that consider multiple performance attributes have been proposed for vendor evaluation p...
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The strategic importance of vendor evaluation is well established in the purchasing literature. Several evaluation methodologies that consider multiple performance attributes have been proposed for vendor evaluation purposes. While these techniques range from scoring models that utilize prior articulation of weights to derive composite scores for vendors to advanced mathematical models, methods that incorporate the inherent variability in vendor's performance attributes have been limited. The primary reason for the lack of development of such models is due to the complexities associated with stochastic approaches. In order to more accurately evaluate the performance of vendors, it is critical to consider variability in vendor attributes. This paper is an attempt to fill this void in vendor evaluation models by presenting a chance-constrained data envelopment analysis (CCDEA) approach in the presence of multiple performance measures that are uncertain. Our paper effectively demonstrates the first application of CCDEA in the area of purchasing, in general, and vendor evaluation, in particular. The model is demonstrated by applying it to a previously reported dataset from a pharmaceutical company. (c) 2004 Elsevier B.V. All rights reserved.
The inequality-constrained least squares (ICLS) problem can be solved by the simplex algorithm of quadratic programming. The ICLS problem may also be reformulated as a Bayesian problem and solved by using the Bayesian...
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The inequality-constrained least squares (ICLS) problem can be solved by the simplex algorithm of quadratic programming. The ICLS problem may also be reformulated as a Bayesian problem and solved by using the Bayesian principle. This paper proposes using the aggregate constraint method of non-linear programming to solve the ICLS problem by converting many inequality constraints into one equality constraint, which is a basic augmented Lagrangean algorithm for deriving the solution to equality-constrained non-linear programming problems. Since the new approach finds the active constraints, we can derive the approximate algorithm-dependent statistical properties of the solution. As a result, some conclusions about the superiority of the estimator can be approximately made. Two simulated examples are given to show how to compute the approximate statistical properties and to show that the reasonable inequality constraints can improve the results of geodetic network with an ill-conditioned normal matrix.
In this paper, HS conjugate gradient method for minimizing a continuously differentiable function f on R-n is modified to have global convergence property. Firstly, it is shown that, using reverse modulus of continuit...
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In this paper, HS conjugate gradient method for minimizing a continuously differentiable function f on R-n is modified to have global convergence property. Firstly, it is shown that, using reverse modulus of continuity function and forcing function, the new method for solving unconstrained optimization can work for a continuously differentiable function with Curry-Altman's step size rule and a bounded level set. Secondly, by using comparing technique, some general convergence properties of the new method with Armijo step size rule are established. Numerical results show that the new algorithms are efficient.
A numerical method for solving a special class of optimal control problems is given. The solution is based on state parametrization as a polynomial with unknown coefficients. This converts the problem to a non-linear ...
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A numerical method for solving a special class of optimal control problems is given. The solution is based on state parametrization as a polynomial with unknown coefficients. This converts the problem to a non-linear optimization problem. To facilitate the computation of optimal coefficients, an improved iterative method is suggested. Convergence of this iterative method and its implementation for numerical examples are also given.
The study presents a comprehensive methodology for the appraisal of C-stock expansion in existing forests as a forest management activity according to Art. 3.4 of the Kyoto Protocol. It allows for producer costs of ca...
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We propose a novel method for the fast synthesis of low complexity model-based optical proximity correction (OPC) and phase shift masks (PSM) to improve the resolution and pattern fidelity of optical microlithography....
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ISBN:
(纸本)0819461970
We propose a novel method for the fast synthesis of low complexity model-based optical proximity correction (OPC) and phase shift masks (PSM) to improve the resolution and pattern fidelity of optical microlithography. We use the pixel-based mask representation, a continuous function formulation, and gradient based iterative optimization techniques to solve the above inverse problem. The continuous function formulation allows analytic calculation of the gradient. Pixel-based parametrization provides tremendous liberty in terms of the features possible in the synthesized masks, but also suffers the inherent disadvantage that the masks are very complex and difficult to manufacture. We therefore introduce the regularization framework;a useful tool which provides the flexibility to promote certain desirable properties in the solution. We employ the above framework to ensure that the estimated masks have only two or three (allowable) transmission values and are also comparatively simple and easy to manufacture. The results demonstrate that we are able to bring the CD on target using OPC masks. Furthermore, we were also able to boost the contrast of the aerial image using attenuated, strong, and 100% transmission phase shift masks. Our algorithm automatically (and optimally) adds assist-bars, do-ears, serifs, anti-serifs, and other custom structures best suited for printing the desired pattern.
This paper presents an application of adaptive neural network modelling and model-based predictive control (MPC) for an engine simulation. A radial basis function (RBF) neural network trained by a recursive least-squa...
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This paper presents an application of adaptive neural network modelling and model-based predictive control (MPC) for an engine simulation. A radial basis function (RBF) neural network trained by a recursive least-squares (RLS) algorithm is compared with the network with fixed parameters and demonstrated to be more suitable for modelling the crankshaft speed, the intake manifold pressure, and the manifold temperature. Based on the obtained adaptive neural network model, an MPC strategy for controlling the crankshaft speed is realized successfully. A reduced Hessian method, a newly developed sequential quadratic programming (SQP) method for solving non-linear programming (NLP) problems, is implemented to solve the non-linear optimization in MPC. Some important modifications are proposed for the algorithm settings in this research to make the reduced Hessian method more appropriate for the adaptive neural network model based predictive control strategy of internal combustion (IC) engines.
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