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Treatment Planning for Volumetric-Modulated Arc Therapy: Model and Heuristic Algorithms

IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING 2015年第1期12卷 116-126页

作者： Song, Jie Shi, Zhongshun Sun, Bofei Shi, Leyuan Peking Univ Dept Ind Engn & Management Beijing 100871 Peoples R China

In this paper, we study the radiation treatment planning optimization for Volumetric-Modulated Arc Therapy (VMAT). A nonlinear mixed integer programming model is formulated, then the linearization technique is used, and the resulting mixed integer programming model is solved by a heuristic approach based on the Nested-Partitions framework. The approach partitions the feasible region iteratively and constructs a feasible solution by solving the LP relaxation of the original problem. We design two partition strategies: partition by column and expansion from center of aperture. Numerical results with clinical cases show the efficiency of the proposed model and algorithm. Note to Practitioners-VMAT delivers a dose in a continuous manner which requires the dose intensity and aperture shape to be optimized simultaneously. The resulting treatment planning problem becomes very difficult to solve. In this paper, we develop a nonlinear mathematical model based on control points. The frequently used clinical setting such as dose-limit and dose volume constraints as well as multi-leaf collimator (MLC) constraints are considered in the model. We then use a linearization technique to transform the nonlinear treatment planning model to an equivalent mixed integer linear programming (MILP) model. The objective of the MILP model is a penalty function of target underdose and organ at risk (OAR) overdose. Based on the property of the MILP treatment planning problem, an effective heuristic method based on Nested-Partitions framework is developed to solve the MILP problem. The output of the model includes the dose intensity and aperture at each control point. As the prescription dose limit and feasibility of change between adjacent control points are ensured in the model, the output is deliverable through a planning system.

关键词： Heuristics nonlinear mixed integer programming radiation therapy planning volumetric-modulated arc therapy (VMAT)

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Train scheduling for minimizing passenger waiting time with time-dependent demand and skip-stop patterns: nonlinear integer programming models with linear constraints

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TRANSPORTATION RESEARCH PART B-METHODOLOGICAL 2015年 76卷 117-135页

作者： Niu, Huimin Zhou, Xuesong Gao, Ruhu Lanzhou Jiaotong Univ Sch Traff & Transportat Lanzhou 730070 Peoples R China Arizona State Univ Sch Sustainable Engn & Built Environm Tempe AZ 85287 USA

This paper focuses on how to minimize the total passenger waiting time at stations by computing and adjusting train timetables for a rail corridor with given time-varying origin-to-destination passenger demand matrices. Given predetermined train skip-stop patterns, a unified quadratic integer programming model with linear constraints is developed to jointly synchronize effective passenger loading time windows and train arrival and departure times at each station. A set of quadratic and quasi-quadratic objective functions are proposed to precisely formulate the total waiting time under both minute-dependent demand and hour-dependent demand volumes from different origin-destination pairs. We construct mathematically rigorous and algorithmically tractable nonlinear mixed integer programming models for both real-time scheduling and medium-term planning applications. The proposed models are implemented using general purpose high-level optimization solvers, and the model effectiveness is further examined through numerical experiments of real-world rail train timetabling test cases. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Train timetable Passenger waiting time Time-varying demand Skip-stop pattern nonlinear mixed integer programming

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A harmony search-based memetic optimization model for integrated production and transportation scheduling in MTO manufacturing

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OMEGA-INTERNATIONAL JOURNAL OF MANAGEMENT SCIENCE 2017年第PartB期66卷 327-343页

作者： Guo, Zhaoxia Shi, Leyuan Chen, Longchao Liang, Yong Sichuan Univ Sch Business Chengdu 610065 Peoples R China Univ Wisconsin Dept Ind & Syst Engn Madison WI 53706 USA Tsinghua Univ Sch Econ & Management Beijing 100084 Peoples R China

This paper investigates an integrated production and transportation scheduling problem in an MTO supply chain. A harmony search-based memetic optimization model is developed to handle this problem, in which certain heuristic procedures are proposed to convert the investigated problem into an order assignment problem. A novel improvisation process is also proposed to improve the optimum-seeking performance. The effectiveness of the proposed model is validated by numerical experiments. The experimental results show that (1) the proposed model can solve the investigated problem effectively and that (2) the proposed memetic optimization process exhibits better optimum-seeking performance than genetic algorithm-based and traditional memetic optimization processes. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Supply chain scheduling nonlinear mixed integer programming Harmony search Memetic algorithms

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Analysis of the single-vehicle cyclic inventory routing problem

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INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE 2012年第11期43卷 2040-2049页

作者： Aghezzaf, El-Houssaine Zhong, Yiqing Raa, Birger Mateo, Manel Ghent Univ UGent Fac Engn Dept Ind Management B-9052 Zwijnaarde Belgium Univ Ghent Fac Econ Dept Informat & Operat Management B-9000 Ghent Belgium Univ Politecn Cataluna ETSEIB Dept Enterprise Management E-08028 Barcelona Spain

The single-vehicle cyclic inventory routing problem (SV-CIRP) consists of a repetitive distribution of a product from a single depot to a selected subset of customers. For each customer, selected for replenishments, the supplier collects a corresponding fixed reward. The objective is to determine the subset of customers to replenish, the quantity of the product to be delivered to each and to design the vehicle route so that the resulting profit (difference between the total reward and the total logistical cost) is maximised while preventing stockouts at each of the selected customers. This problem appears often as a sub-problem in many logistical problems. In this article, the SV-CIRP is formulated as a mixed-integer program with a nonlinear objective function. After a thorough analysis of the structure of the problem and its features, an exact algorithm for its solution is proposed. This exact algorithm requires only solutions of linear mixed-integer programs. Values of a savings-based heuristic for this problem are compared to the optimal values obtained for a set of some test problems. In general, the gap may get as large as 25%, which justifies the effort to continue exploring and developing exact and approximation algorithms for the SV-CIRP.

关键词： inventory-routing nonlinear mixed integer programming exact algorithms

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The redesign of a warranty distribution network with recovery processes

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TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANSPORTATION REVIEW 2015年 77卷 184-197页

作者： Ashayeri, Jalal Ma, Ning Sotirov, Renata Tilburg Univ Dept Econometr & OR NL-5000 LE Tilburg Netherlands

A warranty distribution network provides aftersales warranty services to customers and resembles a closed-loop supply chain network with specific challenges for reverse flows management like recovery, repair, and reflow of refurbished products. We present here a nonlinear and nonconvex mixed integer programming model for the design of the warranty distribution network of a semiconductor company which is operated by an out-sourced third party logistics service provider. The application of the model to the real-life case provides an improved distribution network flow and rearranged warehouse and recovery locations, and resulted in weekly cost savings of 3.4% for the considered item. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Warranty distribution network Supply chain nonlinear mixed integer programming

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Fuzzy programming Approach to an Environmental Supply Chain Network Design Problem

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JOURNAL OF MULTIPLE-VALUED LOGIC AND SOFT COMPUTING 2015年第1期25卷 81-103页

作者： Ozceylan, Eren Pehlivan, Nimet Yapici Paksoy, Turan Gaziantep Univ Dept Business Adm TR-27310 Gaziantep Turkey Selcuk Univ Dept Stat TR-42075 Konya Turkey Selcuk Univ Dept Ind Engn TR-42075 Konya Turkey

Increasing the environmental concerns with legislations and responsibilities are forcing enterprises to take an attention at the impact of their supply chain operations on the environment. An optimally designed supply chain network is required to provide economic, social and environmental requirements in good flows actualizing between suppliers, manufacturers and customers. A nonlinear mixed integer programming model is proposed with the aimed of optimally determining consumed fuel, emitted CO2, driver and transportation costs in this study. However, real world supply chain operations are occurred in a highly dynamic and imprecise environment. Thus, a fuzzy mathematical programming approach is applied to cope with uncertainty in the capacities and demands. The proposed fuzzy model is validated and also compared with different fuzzy mathematical programming approaches through an example, where its applicability is demonstrated for managerial insights.

关键词： Environmental impacts fuzzy mathematical programming nonlinear mixed integer programming supply chain network design

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Modeling and optimizing the integrated problem of closed-loop supply chain network design and disassembly line balancing

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TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANSPORTATION REVIEW 2014年 61卷 142-164页

作者： Ozceylan, Eren Paksoy, Turan Bektas, Tolga Gaziantep Univ Dept Business Adm TR-27310 Gaziantep Turkey Univ Southampton Fac Business & Law Southampton Management Sch Southampton SO17 1BJ Hants England Selcuk Univ Dept Ind Engn TR-42031 Konya Turkey

This paper describes an integrated model that jointly optimizes the strategic and tactical decisions of a closed-loop supply chain (CLSC). The strategic level decisions relate to the amounts of goods flowing on the forward and reverse chains. The tactical level decisions concern balancing disassembly lines in the reverse chain. The objective is to minimize costs of transportation, purchasing, refurbishing, and operating the disassembly workstations. A nonlinear mixed integer programming formulation is described for the problem. Numerical examples are presented using the proposed model. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： nonlinear mixed integer programming Closed-loop supply chain network design Disassembly line balancing

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OR TOOLS FOR TACTICAL FREIGHT TRANSPORTATION-PLANNING

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EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 1988年第3期33卷 290-297页

作者： CRAINIC, TG ROY, J UNIV QUEBEC DEPT SCI ADMCP 8888 SUCC AMONTREAL H3C 3P8QUEBECCANADA

We have developed a general modelling and algorithmic framework, based on mathematical programming techniques for the tactical planning of freight transportation. This approach generates, evaluates and selects operating strategies by globally considering the service network of the company and the routing of the freight through this network under the double criteria of economic efficiency and service quality. This approach has been, and continues to be, applied to planning problems of freight transportation by rail and by truck (the 'less-than-truck-load' problem). This paper presents an overview of the methodology and some results from our tests, as well as the general design of the planning tool that we are now constructing. [ABSTRACT FROM AUTHOR]

关键词： freight transportation network optimization nonlinear mixed integer programming rail transportation road transportation Tactical planning

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Planning Life Tests for Burr XII Distributed Products Under Progressive Group-censoring with Cost Considerations

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GAZI UNIVERSITY JOURNAL OF SCIENCE 2012年第2期25卷 425-434页

作者： Akdogan, Yunus Kus, Coskun Wu, Shuo-Jye Selcuk Univ Fac Sci Dept Stat 42250 Campus Konya Turkey Tamkang Univ Dept Stat New Taipei 25137 Taiwan

In this paper, a progressive type I group-censoring life test for Burr XII distribution is considered. We use the maximum likelihood method to obtain the point estimators of the Burr XII parameters. The approximate confidence intervals for the parameters of Burr XII distribution are also obtained. We use modified algorithm proposed by Kus et al. [20] to decide the number of test units, number of inspections, and length of inspection interval under a restricted budget of experiment such that the determinant of the asymptotic variances-covariance of estimators of parameters is minimum. A numerical example is presented to illustrate the proposed approach. The sensitivity analysis is also investigated.

关键词： D-Optimality Grouped data Interval censoring nonlinear mixed integer programming Maximum likelihood method Progressive censoring

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OPTIMIZATION ANALYSIS OF FLEXIBLE CELLULAR MANUFACTURING - ROUTE SELECTION AND DETERMINING THE OPTIMAL PRODUCTION CONDITIONS FOR ORDERED PRODUCTS

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EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 1993年第3期69卷 399-412页

作者： SONG, SJ CHOI, JH KYOTO UNIV DEPT PRECIS ENGNSAKYO KUKYOTO 606JAPAN

This paper describes a procedure for optimizing the route selection and production conditions considering alternate process plans in a cellular manufacturing environment. The type of production is mainly production-to-order which deals with the unexpected products resulting from changing environmental conditions. Flexible cellular manufacturing can be viewed as a complete unification of both flexible manufacturing process and flexible production management. The integrated problem for designing flexible cellular manufacturing associated with determining the optimal values of the machining speeds, overtime, and intercell flow is formulated as a nonlinear mixed integer programming (NMIP) problem in order to minimize the total incremental production cost. This is achieved by introducing marginal cost analysis into the NMIP, to obtain optimal machining speed, overtime, intercell flow, and routing. The application of this procedure offers greater flexibility to take advantage of cellular manufacturing due to optimum use of resources. A solution procedure for this problem was developed and a numerical example is included.

关键词： JOBBING PRODUCTION FLEXIBLE INTEGRATED CELLULAR MANUFACTURING CELLULAR LAYOUT PROCESS PLANNING MAKE-TO-ORDER PRODUCTION MAKE-TO-STOCK PRODUCTION nonlinear mixed integer programming PRODUCTION CONDITIONS

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