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A three-level problem-centric strategy for selecting NMR precursor labeling and analytes

METABOLIC ENGINEERING 2006年第5期8卷 491-507页

作者： Ghosh, Soumitra Grossmann, Ignacio E. Ataai, Mohammad M. Domach, Michael M. Carnegie Mellon Univ Dept Chem Engn Pittsburgh PA 15213 USA Carnegie Mellon Univ Dept Chem & Petr Engn Pittsburgh PA 15213 USA

We have developed a sequential set of computational screens that may prove useful for evaluating analyte sets for their ability to accurately report on metabolic fluxes. The methodology is problem-centric in that the screens are used in the context of a particular metabolic engineering problem. That is, flux bounds and alternative flux routings are first identified for a particular problem, and then the information is used to inform the design of nuclear magnetic resonance (NMR) experiments. After obtaining the flux bounds via MILP, analytes are first screened for whether the predicted NMR spectra associated with various analytes can differentiate between different extreme point (or linear combinations of extreme point) flux solutions. The second screen entails determining whether the analytes provide unique flux values or multiple flux solutions. Finally, the economics associated with using different analytes is considered in order to further refine the analyte selection process in terms of an overall utility index, where the index summarizes the cost-benefit attributes by quantifying benefit (contrast power) per cost (e.g., NMR instrument time required). We also demonstrate the use of an alternative strategy, the Analytical Hierarchy Process, for ranking analytes based on the individual experimentalist's-generated weights assigned for the relative value of flux scenario contrast, unique inversion of NMR data to fluxes, etc. (C) 2006 Elsevier Inc. All rights reserved.

关键词： metabolic flux analysis nuclear magnetic resonance non-linear programming global optimization E. coli

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Location of slaughterhouses under economies of scale

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EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2006年第2期175卷 740-750页

作者： van der Broek, John Schutz, Peter Stougie, Leen Tomasgard, Asgeir Eindhoven Univ Technol Dept Math & Comp Sci & CWI NL-1090 GB Amsterdam Netherlands Eindhoven Univ Technol Dept Math & Comp Sci & NS Travellers NL-5600 MB Eindhoven Netherlands NTNU Dept Ind Econ & Technol Management SINTEF Technol & Soc N-7491 Trondheim Norway

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.

关键词： location integer programming non-linear programming branch-and-bound economies of scale

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Identification and estimation of statistical functionals using incomplete data

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JOURNAL OF ECONOMETRICS 2006年第2期132卷 445-459页

作者： Horowitz, Joel L. Manski, Charles F. Northwestern Univ Dept Econ Evanston IL 60208 USA

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.

关键词： bounds missing data non-linear programming

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A non-linear possibilistic regression approach to model functional relationships in product planning

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2006年第11-12期28卷 1175-1181页

作者： Chen, YZ Chen, L Shanghai 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 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 linear programming in possibilistic regression analysis is used, some coefficients tend to become crisp because of the characteristic of linear programming. 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 linear programming approach. An emulsification dynamite packing-machine design is used to illustrate the performance of the proposed approach.

关键词： house of quality non-linear programming possibilistic regression product planning quality function deployment triangular fuzzy number

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Vendor performance with supply risk: A chance-constrained DEA approach

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INTERNATIONAL JOURNAL OF PRODUCTION ECONOMICS 2006年第2期100卷 212-222页

作者： Talluri, S Narasimhan, R Nair, A Michigan State Univ Dept Marketing & Supply Chain Management Eli Braod Coll Business E Lansing MI 48824 USA Business Complex E Lansing MI 48824 USA Auburn Univ Coll Business Auburn AL 36849 USA

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.

关键词： chance-constrained programming non-linear programming purchasing stochastic data envelopment analysis

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An aggregate constraint method for inequality-constrained least squares problems

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JOURNAL OF GEODESY 2006年第12期79卷 705-713页

作者： Peng, JH Guo, CX Zhang, HP Shong, SL Chongqing Univ Sch Civil Engn Chongqing 400045 Peoples R China Chinese Acad Sci Shanghai Astron Observ Shanghai 200030 Peoples R China State Bur Surveying & Mapping Geodet Data Proc Ctr Xian 710054 Peoples R China Guangdong Univ technol Fac Construct Guangzhou Guangdong Peoples R China

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.

关键词： inequality-constrained least squares Bayesian estimation minimax estimation non-linear programming aggregate constraint method

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GLOBAL CONVERGENCE OF MODIFIED HS CONJUGATE GRADIENT METHOD

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JOURNAL OF APPLIED MATHEMATICS AND COMPUTING 2006年第3期22卷 289-297页

作者： Sun Qingying Liu Qiu China Univ Petr Sch Math & Computat Sci Dongying 257061 Peoples R China

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.

关键词： non-linear programming memory gradient method Curry-Altman's step size rule Armijo step size rule convergence numerical experiment

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A numerical method for solving optimal control problems using state parametrization

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NUMERICAL ALGORITHMS 2006年第2期42卷 165-169页

作者： Mehne, H. Hashemi Borzabadi, A. Hashemi Aerosp Res Inst Tehran 14665834 Iran Damghan Univ Basic Sci Damghan 36715364 Iran

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.

关键词： optimal control non-linear programming state parametrization approximation

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Expanding carbon stocks in existing forests - A methodological approach for cost appraisal at the enterprise level

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Mitigation and Adaptation Strategies for Global Change 2006年第3期11卷 579-605页

作者： Knoke, Thomas Weber, Michael Unit of Forest Inventory and Management Technische Universität München 85354 Freising Am Hochanger 13 Germany Institute of Silviculture Technische Universität München 85354 Freising Am Hochanger 13 Germany

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 carbon sequestration in forest enterprises to be derived. The methodology is based on a non-linear programming approach considering economic optimisation as well as ecological, social and sustainability needs through constraints and risk integration. While introducing further constraints on carbon stocks, the carbon stored in forest biomass was increased in periodic increments. However, while extending the carbon stocks, the ecological and social constraints as well as sustainability requirements are not to be violated. Costs were derived for every additional Mg (Megagrams) of C per ha sequestered in comparison to a baseline management. Two basic cases were considered: First, a permanent carbon sequestration was assumed. Secondly, a temporary storage of additional carbon over 10 years was supposed. The potential willingness of buyers of carbon certificates to pay for temporary carbon sequestration was derived by a financial consideration. We assumed that, for a buyer, the value of a temporary carbon sequestration certificate would be equivalent to the return on the savings because an investment in technical measures on reduction of carbon emissions can be postponed. Temporary carbon storage proved to be an interesting alternative when compared with permanent sequestration of carbon. Basically the costs of additional Mg C sequestered increased when carbon sequestration in periodic increments was enlarged. Given a market price of 11.42 Euro per Mg C for 10-year temporary carbon storage, the management of the forest could expand additional sequestration up to 6 Mg C per ha. Doing so, additional carbon sequestration generates an economic surplus as the costs of the last Mg C per ha would equal the market price. © Springer 2006.

关键词： Carbon prices non-linear programming Temporary carbon sequestration Uncertainty

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OPC and PSM design using inverse lithography: A non-linear optimization approach

OPC and PSM design using inverse lithography: A non-linear o...

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Conference on Optical Microlithography XIX

作者： Poonawala, Amyn Milanfar, Peyman Univ Calif Santa Cruz Dept Comp Engn Santa Cruz CA 95064 USA Univ Calif Santa Cruz Dept Elect Engn Santa Cruz CA 95064 USA

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.

关键词： inverse lithography OPC PSM pixel-based approach non-linear programming optimization regularization low-complexity

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