检索结果-内蒙古大学图书馆

Packing unequal rectangles and squares in a fixed size circular container using formulation space search

COMPUTERS & OPERATIONS RESEARCH 2018年 94卷 106-117页

作者： Lopez, C. O. Beasley, J. E. Univ Nacl Autonoma Mexico Fac Sci Mexico City DF Mexico Brunel Univ Math Sci Uxbridge UB8 3PH Middx England JB Consultants Morden England

In this paper we formulate the problem of packing unequal rectangles/squares into a fixed size circular container as a mixed-integer nonlinear program. Here we pack rectangles so as to maximise some objective (e.g. maximise the number of rectangles packed or maximise the total area of the rectangles packed). We show how we can eliminate a nonlinear maximisation term that arises in one of the constraints in our formulation. We indicate the amendments that can be made to the formulation for the special case where we are maximising the number of squares packed. A formulation space search heuristic is presented and computational results given for publicly available test problems involving up to 30 rectangles/squares. Our heuristic deals with the case where the rectangles are of fixed orientation (so cannot be rotated) and with the case where the rectangles can be rotated through ninety degrees. (C) 2018 Elsevier Ltd. All rights reserved.

关键词： Formulation space search mixed-integer nonlinear program Rectangle packing Square packing

来源：评论

学校读者我要写书评

暂无评论

Robust optimisation to design a dynamic cellular manufacturing system integrating group layout and workers' assignment

引用

EUROPEAN JOURNAL OF INDUSTRIAL ENGINEERING 2021年第3期15卷 319-351页

作者： Lashgari, Mohsen Kia, Reza Jolai, Fariborz Univ Tehran Coll Engn Sch Ind Engn Tehran Iran German Univ Technol Oman GUtech Fac Business & Econ Dept Logist Tourism & Serv Management Muscat Oman Islamic Azad Univ Firoozkooh Branch Dept Ind Engn Firoozkooh Iran

In this paper, a robust optimisation approach is proposed to solve a mathematical model integrating cell formation, group layout and operators assignment decisions under a dynamic situation. The main aim of applying a robust approach is to obtain an optimal design of a cellular manufacturing system that is robust with respect to encountered uncertainties in part demands and processing times. The integrated model incorporates several design attributes including operations sequence, group layout, equal-area facilities multi-rows layout, flexible cell reconfiguration, operators hiring/firing and training, operator available time, limitations of cell size and uncertain processing times and part demands. Two illustrative numerical examples are solved to investigate the validity of the robust model. Regarding the NP-hardness of the proposed model, an efficient simulated annealing algorithm is implemented. Some test problems either generated randomly or taken from the literature are solved and the results are compared with the ones obtained using CPLEX.

关键词： dynamic cellular manufacturing system robust optimisation group layout worker assignment mixed-integer nonlinear program simulated annealing

来源：评论

学校读者我要写书评

暂无评论

Medium- and low-voltage planning of radial electric power distribution systems considering reliability

引用

IET GENERATION TRANSMISSION & DISTRIBUTION 2017年第9期11卷 2212-2221页

作者： Rupolo, Diogo Pereira, Benvindo Rodrigues, Jr. Contreras, Javier Sanches Mantovani, Jose Roberto Sao Paulo State Univ Dept Elect Engn UNESP Ilha Solteira Brazil Univ Sao Paulo Dept Elect Engn Sao Carlos SP Brazil Univ Castilla La Mancha ETS Ingn Ind Ciudad Real Spain

This study proposes a new methodology to carry out distribution network planning considering medium-voltage (MV) and low-voltage (LV) systems. The integrated planning problem of a MV/LV distribution system is formulated as a mixed-integer non-linear program and aims at minimising investment (substations, transformers, conductors, poles, and structures), operating, and reliability costs. The coupling constraints between MV/LV networks are represented by MV/LV modelling transformers through the power flow equations. The mathematical model is solved by the general variable neighborhood search metaheuristic method, which allows us to explore the search space through intensification and diversification criteria. The proposed methodology is applied in a system with 50 buses at the MV level and 410 buses at the LV level.

关键词： power distribution planning power distribution reliability integer programming nonlinear programming load flow search problems low-voltage planning medium-voltage planning radial electric power distribution systems distribution network planning mixed-integer nonlinear program power flow equations variable neighborhood search metaheuristic method

来源：评论

学校读者我要写书评

暂无评论

Connected Vehicle-Based Traffic Signal Coordination

引用

Engineering 2020年第12期6卷 1463-1472页

作者： Wan Li Xuegang Ban Oak Ridge National Laboratory KnoxvilleTN 37932USA University of Washington SeattleWA 98195USA

This study presents a connected vehicles(CVs)-based traffic signal optimization framework for a coordinated arterial *** signal optimization and coordination problem are first formulated in a centralized scheme as a mixed-integer nonlinear program(MINLP).The optimal phase durations and offsets are solved together by minimizing fuel consumption and travel time considering an individual vehicle’s *** to the complexity of the model,we decompose the problem into two levels:an intersection level to optimize phase durations using dynamic programming(DP),and a corridor level to optimize the offsets of all *** order to solve the two-level model,a prediction-based solution technique is *** proposed models are tested using traffic simulation under various *** with the traditional actuated signal timing and coordination plan,the signal timing plans generated by solving the MINLP and the two-level model can reasonably improve the signal control *** considering varies vehicle types under high demand levels,the proposed two-level model reduced the total system cost by 3.8%comparing to baseline actuated *** reduced the system cost by 5.9%.It also suggested that coordination scheme was beneficial to corridors with relatively high demand *** intersections with major and minor street,coordination conducted for major street had little impacts on the vehicles at the minor street.

关键词： Connected vehicles Traffic signal coordination Dynamic programming Two-level optimization mixed-integer nonlinear program

来源：评论

学校读者我要写书评

暂无评论

mixed-integer and Conditional Trajectory Planning for an Autonomous Mining Truck in Loading/Dumping Scenarios: A Global Optimization Approach

IEEE TRANSACTIONS ON INTELLIGENT VEHICLES

引用

IEEE TRANSACTIONS ON INTELLIGENT VEHICLES 2023年第2期8卷 1512-1522页

作者： Li, Bai Ouyang, Yakun Li, Xiaohui Cao, Dongpu Zhang, Tantan Wang, Yaonan State Key Lab Adv Design & Mfg Vehicle Body Changsha 410082 Peoples R China Hunan Univ Coll Mech & Vehicle Engn Changsha 410082 Peoples R China Natl Univ Def Technol Coll Intelligence Sci Changsha 410073 Peoples R China Tsinghua Univ Sch Vehicle & Mobil Beijing 100084 Peoples R China Hunan Univ Coll Elect & Informat Engn Changsha 410082 Peoples R China Natl Engn Lab Robot Visual Percept & Control Changsha 410082 Peoples R China

Trajectory planning for a heavy-duty mining truck near the loading/dumping sites of an open-pit mine is difficult. As opposed to trajectory planning for a small-sized passenger car in a parking lot, trajectory planning for a heavy-duty mining truck involves complex factors in vehicle kinematics and environment. These factors make the concerned trajectory planning scheme a mixed-integer nonlinear program (MINLP) incorporated with conditional constraints (denoted as C-MINLP). MINLP solvers can neither deal with conditional constraints nor find global optima in real time. Instead of solving the C-MINLP directly, we build a from-coarse-to-fine framework so that the coupled difficulties (the mixed integral variables, conditional constraints, and the demand for global optimality) are divided and conquered. At the coarse search stage, a global-optimality-enhanced hybrid A* search algorithm is proposed to find a near-optimal coarse trajectory with the mixed integral variables, conditional kinematic constraints, and global optimality considered. The coarse trajectory is further polished at the refinement stage, wherein the nominal C-MINLP is simplified as a small-scale NLP. The solution to the NLP is an optimized trajectory, which does not violate the complex constraints in the nominal C-MINLP. This indicates that conversion from the C-MINLP to an NLP is efficient with the help of a high-quality coarse trajectory.

关键词： Trajectory planning Trajectory Kinematics Costs Stochastic processes Planning Cost function autonomous mining vehicle computational optimal control mixed-integer nonlinear program

来源：评论

学校读者我要写书评

暂无评论

Reformulation, linearization, and a hybrid iterated local search algorithm for economic lot-sizing and sequencing in hybrid flow shop problems

引用

COMPUTERS & OPERATIONS RESEARCH 2019年 104卷 127-138页

作者： Zohali, Hassan Naderi, Bahman Mohammadi, Mohammad Roshanaei, Vahid Kharazmi Univ Dept Ind Engn Fac Engn Tehran Iran Univ Windsor Dept Mech Automot & Mat Engn Fac Engn Windsor ON Canada Univ Toronto Rotman Sch Management Dept Operat Management & Stat Toronto ON Canada

We study an integrated economic lot-sizing and sequencing problem (ELSP) in the hybrid flow shop manufacturing setting with unlimited intermediate buffers in a finite planning horizon. The ELSP entails making two simultaneous decisions regarding (i) the manufacturing sequences of products, and (ii) their production quantity. The objective is to minimize the total cost, consisting of inventory holding and set-up costs. To solve this problem, we first develop a novel mixed-integer nonlinear programming (MINLP) model that improves an existing MINLP model in the literature. We then present a novel linearization technique that transforms these two MINLP models into effective mixed-integer linear programming (MILP) models. Additionally, we develop an effective algorithm that hybridizes the iterated local search algorithm with an approximate function. We conduct comprehensive experiments to compare the performance of MILPs+CPLEX with that of MINLPs+BARON. Additionally, our proposed algorithm is compared with four existing metaheuristic algorithms in the literature. Computational results demonstrate that our novel MINLP formulation and its linearized variant significantly improve the solvability and optimality gap of an existing MINLP formulation and its linearized variant. We also show that our new hybrid iterated local search algorithm substantially improves computational performance and optimality gap of the mathematical models and the existing algorithms in the literature, on large-size instances of the problem. (C) 2018 Elsevier Ltd. All rights reserved.

关键词： Lot-sizing Sequencing Hybrid flow shop mixed-integer nonlinear program Linearization mixed-integer linear program Hybrid iterated local search

来源：评论

学校读者我要写书评

暂无评论

MINLP formulations for continuous piecewise linear function fitting

引用

COMPUTATIONAL OPTIMIZATION AND APPLICATIONS 2021年第1期79卷 223-233页

作者： Goldberg, Noam Rebennack, Steffen Kim, Youngdae Krasko, Vitaliy Leyffer, Sven Bar Ilan Univ Ramat Gan Israel Karlsruhe Inst Technol Karlsruhe Germany Argonne Natl Lab Lemont IL 60439 USA Colorado Sch Mines Golden CO 80401 USA

We consider a nonconvex mixed-integer nonlinear programming (MINLP) model proposed by Goldberg et al. (Comput Optim Appl 58:523-541, 2014. ) for piecewise linear function fitting. We show that this MINLP model is incomplete and can result in a piecewise linear curve that is not the graph of a function, because it misses a set of necessary constraints. We provide two counterexamples to illustrate this effect, and propose three alternative models that correct this behavior. We investigate the theoretical relationship between these models and evaluate their computational performance.

关键词： mixed-integer nonlinear program Linear spline regression Branch-and-bound Reformulation

来源：评论

学校读者我要写书评

暂无评论

Efficient real time optimization using a data-driven piecewise affine model

引用

COMPUTERS & CHEMICAL ENGINEERING 2019年 125卷 545-557页

作者： Yang, Yu Kelly, Jasper Calif State Univ Long Beach Dept Chem Engn Long Beach CA 90840 USA

A data-driven real time optimization (RTO) scheme is proposed for complex processes under uncertainties. The objective is to optimize the economic performance of a plant when its first-principle model is difficult to obtain. To this end, a piecewise affine (PWA) model is built by fitting the operating data to predict the production of a process. The trust region of the PWA model is also characterized to ensure reliable predictions. Then, the RTO is formulated as a mixed-integer nonlinear program (MINLP) based on the PWA model. To alleviate the computational demands, we also develop a dynamic programming (DP) scheme that solves the RTO to a near-optimal solution. Two case studies show that the PWA model can accurately forecast the real productions when the process is operated within the trust region, and the proposed DP scheme takes less time to find a better solution than the state-of-the-art solver for the large-scale MINLP. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Real time optimization Dynamic programming mixed-integer nonlinear program Piecewise affine model

来源：评论

学校读者我要写书评

暂无评论

GLOBAL OPTIMIZATION OF nonlinear NETWORK DESIGN

引用

SIAM JOURNAL ON OPTIMIZATION 2013年第1期23卷 268-295页

作者： Raghunathan, Arvind U. United Technol Res Ctr E Hartford CT 06118 USA

A novel approach for obtaining globally optimal solutions to design of networks with nonlinear resistances and potential driven flows is proposed. The approach is applicable to networks where the potential loss on an edge in the network is governed by a convex and strictly monotonically increasing function of flow rate. We introduce a relaxation of the potential loss constraint and formulate the design problem as a mixed-integer nonlinear program. A linearization-based approach with tailored cuts is proposed that improves the computational efficiency over a standard implementation. We have also implemented a simple heuristic approach for finding feasible solutions at the root node and during the search process. The algorithm has been implemented with IBM-ILOG CPLEX and is shown to be computationally effective on a number of examples from the literature.

关键词： nonlinear resistance networks mixed-integer nonlinear program linearization-based branch-and-cut

来源：评论

学校读者我要写书评

暂无评论

Quantum Topology Optimization via Quantum Annealing

IEEE TRANSACTIONS ON QUANTUM ENGINEERING

引用

IEEE TRANSACTIONS ON QUANTUM ENGINEERING 2023年第1期4卷 1页

作者： Ye, Zisheng Qian, Xiaoping Pan, Wenxiao Univ Wisconsin Dept Mech Engn Madison WI 53706 USA

We present a quantum annealing-based solution method for topology optimization (TO). In particular, we consider TO in a more general setting, i.e., applied to structures of continuum domains where designs are represented as distributed functions, referred to as continuum TO problems. According to the problem's properties and structure, we formulate appropriate subproblems that can be solved on an annealing-based quantum computer. The methodology established can effectively tackle continuum TO problems formulated as mixed-integer nonlinear programs. To maintain the resulting subproblems small enough to be solved on quantum computers currently accessible with small numbers of qubits and limited connectivity, we further develop a splitting approach that splits the problem into two parts: the first part can be efficiently solved on classical computers, and the second part with a reduced number of variables is solved on a quantum computer. By such, a practical continuum TO problem of varying scales can be handled on the D-Wave quantum annealer. More specifically, we concern the minimum compliance, a canonical TO problem that seeks an optimal distribution of materials to minimize the compliance with desired material usage. The superior performance of the developed methodology is assessed and compared with the state-of-the-art heuristic classical methods, in terms of both solution quality and computational efficiency. The present work hence provides a promising new avenue of applying quantum computing to practical designs of topology for various applications.

关键词： Optimization Quantum annealing Annealing Linear programming Layout Logic gates Computational efficiency mixed-integer nonlinear program quadratic unconstrained binary optimization quantum annealing topology optimization (TO)

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：