检索结果-内蒙古大学图书馆

Mathematical programming models and algorithms for a class-faculty assignment problem

EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2006年第2期173卷 488-507页

作者： Al-Yakoob, Salem M. Sherali, Hanif D. Kuwait Univ Coll Sci Dept Math & Comp Sci Safat 13060 Kuwait Virginia Polytech Inst & State Univ Grado Dept Ind & Syst Engn 0118 Blacksburg VA 24061 USA

This paper presents mathematical programming models for assigning faculty members to classes including, among typical academic class scheduling issues, certain specialized central policies at Kuwait University. The time-slots for classes are initially assumed to be given and an integer programming model (CFAM) is constructed to solve the resulting problem, which aims to minimize the individual and collective dissatisfaction of faculty members in a fair fashion, where dissatisfaction is measured by a function of the assignment of faculty members to time-slots and specific classes. In order to enhance the quality of results obtained in practice, the model is modified (ECFAM) so that the time-slots for the classes can be changed, however, with restrictions related to efficient facility utilization and permitting an administratively regulated maximum number of changes. Gender-based modeling considerations are also introduced in order to maintain desirable class offering patterns. Computational results are presented based on solving the models directly by the CPLEX-MIP (version 7.5) package and also using a specialized LP-based heuristic. The faculty schedules generated via the proposed approach based on a number of case studies related to the Department of Mathematics and Computer Science at Kuwait University reveal that this approach yields improved schedules in terms of fairness and enhanced satisfaction levels among faculty members. (c) 2005 Elsevier B.V. All rights reserved.

关键词： timetabling class scheduling mixed-integer programming employee scheduling gender policies

来源：评论

学校读者我要写书评

暂无评论

A simultaneous optimization approach for off-line blending and scheduling of oil-refinery operations

引用

COMPUTERS & CHEMICAL ENGINEERING 2006年第4期30卷 614-634页

作者： Méndez, CA Grossmann, IE Harjunkoski, I Kaboré, P Carnegie Mellon Univ Dept Chem Engn Pittsburgh PA 15213 USA ABB Corp Res Ctr Ladenburg Germany

This paper presents a novel MILP-based method that addresses the simultaneous optimization of the off-line blending and the short-term scheduling problem in oil-refinery applications. Depending on the problem characteristics as well as the required flexibility in the solution, the model can be based on either a discrete or a continuous time domain representation. In order to preserve the model's linearity, an iterative procedure is proposed to effectively deal with non-linear gasoline properties and variable recipes for different product grades. Thus, the solution of a very complex MINLP formulation is replaced by a sequential MILP approximation. Instead of predefining fixed component concentrations for products, preferred blend recipes can be forced to apply whenever it is possible. Also, different alternatives for coping with infeasible problems are presented. Sufficient conditions for convergence for the proposed approach are presented as well as a comparison with NLP and MINLP solvers to demonstrate that the method provides an effective integrated solution method for the blending and scheduling of large-scale problems. The new method is illustrated with several real world problems requiring very low computational requirements. (c) 2005 Elsevier Ltd. All rights reserved.

关键词： scheduling planning blending refinery operations mixed-integer programming

来源：评论

学校读者我要写书评

暂无评论

Optimal control of investments for quality of supply improvement in electrical energy distribution networks

引用

AUTOMATICA 2006年第8期42卷 1331-1336页

作者： Bemporad, A. de la Pena, D. Munoz Piazzesi, P. Univ Siena Dip Ingn Informaz Siena Italy Univ Sevilla Dep Ingn Sistemas & Automat Seville Spain ENEL Distrubuz Pianifcaz & Controllo Florence Italy

This paper considers the problem of deciding multi-period investments for maintenance and upgrade of electrical energy distribution networks. After describing the network as a constrained hybrid dynamical system, optimal control theory is applied to optimize profit under a complex incentive/penalty mechanism imposed by public authorities. The dynamics of the system and the cost function are translated into a mixed integer optimization model, whose solution gives the optimal investment policy over the multi-period horizon. While for a reduced-size test problem the pure mixed-integer approach provides the best optimal control policy, for real-life large-scale scenarios a heuristic solution is also introduced. Finally, the uncertainty associated with the dynamical model of the network is taken care of by adopting ideas from stochastic programming. (c) 2006 Elsevier Ltd. All rights reserved.

关键词： investment planning optimal control hybrid systems mixed-integer programming stochastic systems

来源：评论

学校读者我要写书评

暂无评论

A multicriteria approach for optimizing bus schedules and school starting times

引用

ANNALS OF OPERATIONS RESEARCH 2006年第1期147卷 199-216页

作者： Fuegenschuh, Armin Martin, Alexander TH Darmstadt D-64289 Darmstadt Germany

In many rural counties pupils on their way to school are a large, if not the largest group of customers for public mass transit. Hence an effective optimization of public mass transit in these regions must include the traffic caused by pupils. Besides a change in the schedules of the buses and the starting times of the trips, the school starting time may become an integral part of the planning process. We discuss the legal framework for this optimization problem in German states and counties and present a multi-objective mixed-integer linear programming formulation for the simultaneous specification of school and trip starting times. For its solution, we develop a two-stage decomposition heuristic and apply it to practical data sets from three different rural German counties.

关键词： multicriteria optimization mixed-integer programming multiple traveling salesman problem time windows

来源：评论

学校读者我要写书评

暂无评论

An efficient MILP model for the short-term scheduling of single stage batch plants

引用

COMPUTERS & CHEMICAL ENGINEERING 2006年第6-7期30卷 1003-1018页

作者： Castro, Pedro A. Grossmann, Ignacio E. INETI Dept Modelacao & Simulacao Proc P-1649037 Lisbon Portugal Carnegie Mellon Univ Dept Chem Engn Pittsburgh PA 15213 USA

This paper presents a multiple time grid continuous time MILP model for the short-term scheduling of single stage, multiproduct batch plants. It can handle both release and due dates and the objective can be either the minimization of total cost or total earliness. This formulation is compared to other mixed-integer linear programming approaches that have appeared in the literature, to a constraint programming model, and to a hybrid mixed-integer linear/constraint programming algorithm. The results show that the proposed formulation is significantly more efficient than the MILP and CP models and comparable to the hybrid model. For one large instance, both methods exceeded the time limit but the hybrid method failed to find a feasible solution. The results also show that a discrete-time formulation performs very efficiently even when a large number of time intervals are used. (c) 2006 Elsevier Ltd. All rights reserved.

关键词： mixed-integer programming constraint programming hybrid strategy resource task network parallel machine scheduling

来源：评论

学校读者我要写书评

暂无评论

Exact and heuristic algorithms for solving the generalized minimum filter placement problem

引用

JOURNAL OF COMBINATORIAL OPTIMIZATION 2006年第3期12卷 231-256页

作者： Mofya, E. Chisonge Smith, J. Cole Univ Arizona Dept Syst & Ind Engn Tucson AZ 85721 USA

We consider a problem of placing route-based filters in a communication network to limit the number of forged address attacks to a prescribed level. Nodes in the network communicate by exchanging packets along arcs, and the originating node embeds the origin and destination addresses within each packet that it sends. In the absence of a validation mechanism, one node can send packets to another node using a forged origin address to launch an attack against that node. Route-based filters can be established at various nodes on the communication network to protect against these attacks. A route-based filter examines each packet arriving at a node, and determines whether or not the origin address could be legitimate, based on the arc on which the packet arrives, the routing information, and possibly the destination. The problem we consider seeks to find a minimum cardinality subset of nodes to filter so that the prescribed level of security is achieved. We formulate a mixed-integer programming model for the problem and derive valid inequalities for this model by identifying polynomially-solvable subgraphs of the communication network. We also present three heuristics for solving the filter placement problem and evaluate their performance against the optimal solution provided by the mixed-integer programming model.

关键词： mixed-integer programming facets heuristics computer network security denial of service attacks

来源：评论

学校读者我要写书评

暂无评论

An optimization model for storage yard management in transshipment hubs

引用

OR SPECTRUM 2006年第4期28卷 539-561页

作者： Lee, Loo Hay Chew, Ek Peng Tan, Kok Choon Han, Yongbin Natl Univ Singapore Dept Ind & Syst Engn Singapore 119260 Singapore

This paper studies a yard storage allocation problem in a transshipment hub where there is a great number of loading and unloading activities. The primary challenge is to efficiently shift containers between the vessels and the storage area so that reshuffling and traffic congestion is minimized. In particular, to reduce reshuffling, a consignment strategy is used. This strategy groups unloaded containers according to their destination vessel. To reduce traffic congestion, a new workload balancing protocol is proposed. A mixed integer-programming model is then formulated to determine the minimum number of yard cranes to deploy and the location where unloaded containers should be stored. The model is solved using CPLEX. Due to the size and complexity of this model two heuristics are also developed. The first is a sequential method while the second is a column generation method. A bound is developed that allows the quality of the solution to be judged. Lastly, a numerical investigation is provided and demonstrates that the algorithms perform adequately on most cases considered.

关键词： port operation storage allocation mixed-integer programming heuristic algorithm column generation

来源：评论

学校读者我要写书评

暂无评论

A two-stage stochastic unit commitment with electricity derivatives

A two-stage stochastic unit commitment with electricity deri...

引用

38th Annual North American Power Symposium (NAPS)

作者： Siriariyaporn, V. Sparrow, F. T. Gotham, D. J. Midwest ISO Inc Carmel IN USA Purdue Univ W Lafayette IN 47907 USA

ISBN: (纸本)9781424402274

A unit commitment problem has long been known in the class of short-term functions and decisions, inherited from vertically integrated utility. In the competitive environment, the problem has become more complicated due to the fact that any action taken will now influence profitability of decision maker such as generation companies, load serving entities, and so forth. Thus, not only do economic agents face operational risks, but they also need to procure their operations against financial risks front volatility in fuel, contract, and electricity prices. This leads to the evolution of stochastic unit commitment in this paper integrating risk management tools, i.e., electricity derivatives, so as to reduce the impacts from both operational and financial risks in the short run. The planning model is structured of stochastic mixed-integer program with recourse cost. A case study will be addressed with preliminary result presenting an improved solution.

关键词： stochastic programming mixed-integer programming unit commitment risk management power portfolio optimization and power system planning and operation

来源：评论

学校读者我要写书评

暂无评论

A MODEL AND FAST OPTIMIZATION METHOD FOR SIGNAL COORDINATION IN A NETWORK

引用

IFAC Proceedings Volumes 2006年第12期39卷 73-78页

作者： Rolf H. Möhring Klaus Nökel Gregor Wuünsch TU Berlin Institute of Mathematics MA 6-1 Straβe des 17.Juni 136 D-10623 Berlin Germany PTV AG Stumpfstraβe 1 D-76131 Karlsruhe Germany

The coordination of signal controls in a traffic network has a significant impact on throughput and journey times. Traditionally, signal coordination is optimized as a separate model step, after route flows have been obtained from an assignment. A better integration of both steps requires a model of signal coordination which admits a fast solution method. We describe such a model and a solution based on mathematical optimization techniques for mixed-integer problems. Compared to existing approaches, our method supports non-uniform cycle lengths and yields optimal solutions (w.r.t. the objective function of our model) in less computation time. We use microsimulation to compare the resulting signal phasing to one obtained from an industry standard model and report on effectiveness and computational effort.

关键词： Traffic Signals Optimization Offsets mixed-integer programming Simulation

来源：评论

学校读者我要写书评

暂无评论

Capacity planning with reconfigurable kits in semiconductor test manufacturing

引用

INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH 2006年第13期44卷 2625-2644页

作者： Zhang, Z. Zhang, M. T. Niu, S. Zheng, L. Tsinghua Univ Dept Ind Engn Beijing 100084 Peoples R China Intel Corp Chandler AZ 85248 USA Intel Prod Shanghai Ltd Shanghai 200131 Peoples R China

To test an integrated circuit (IC) product, both a tester and qualified kits are simultaneously needed. One kit usually consists of six or seven components and is somewhat like a fixture. A remarkable amount of investment will be saved if one allows kit reconfigurations and purchase individual components instead of using entire kits. Unfortunately, this approach of the reconfigurable kit also increase exponentially the complexity of kit management and thus capacity planning due to intricate {product, tester, kit, component} qualification relationships. The paper describes the Automated Capacity Allocation System ( ACAS) developed at Intel Shanghai for generating an optimal capacity and kit-allocation plan for a 9-week horizon. It performs optimization at the component level using mixed-integer programming (MIP) technology. High Buffer Formulation and Tight Workload Formulation are introduced to determine the number of kits needed to guarantee a feasible capacity plan. Detailed analyses of parameter setting, objective prioritizing and formulation comparison were also conducted. With the implementation of the ACAS at Intel, we have already realized millions of dollars in savings from kit purchasing and about 90% man-hour savings in the capacity planning.

关键词： semiconductor manufacturing capacity planning mixed-integer programming kit

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：