检索结果-内蒙古大学图书馆

A new multi-objective mathematical model for the high-level synthesis of integrated circuits

APPLIED MATHEMATICAL MODELLING 2016年第3期40卷 2274-2290页

作者： Aras, Necati Yurdakul, Arda Bogazici Univ Dept Ind Engn Istanbul Turkey Bogazici Univ Dept Comp Engn Istanbul Turkey

An integrated circuit contains millions of components, all of which have to fit in the reserved silicon area and fulfill a defined functionality within a specified amount of execution time. Therefore, the design of an effective integrated circuit is a nontrivial task. Actually, it can be considered as a multi-objective optimization problem with two conflicting objectives: minimizing the total execution time called latency and the total silicon area of the integrated circuit. The overall problem is composed of tightly-coupled subproblems, i.e., determining the allocation of operators that execute the operations, the assignment of operations to operators, and scheduling of the operations. We formulate a multi-objective mixed-integer linear programming model (MOMILP) to solve this complex problem. It is novel since it incorporates decisions about the so-called multiplexers, which are essential components of an integrated circuit. The proposed MOMILP model is solved exactly using an augmented epsilon-constrained method. This enables us to find all the Pareto optimal solutions and hence the Pareto frontier for a given problem instance within a reasonable amount of computation time. The minimum latency and minimum area solutions of our model are 13.20 and 7.24% better on the average than the model that ignores multiplexers. (C) 2015 Elsevier Inc. All rights reserved.

关键词： Integrated circuits Multiobjective optimization mixed-integer linear programming Pareto frontier

来源：评论

学校读者我要写书评

暂无评论

Discrete optimization methods to fit piecewise affine models to data points

引用

COMPUTERS & OPERATIONS RESEARCH 2016年 75卷 214-230页

作者： Amaldi, E. Coniglio, S. Taccari, L. Politecn Milan Dipartimento Elettron Informaz & Bioingn Piazza Leonardo Vinci 32 I-20133 Milan Italy Univ Southampton Dept Math Sci Univ Rd Southampton SO17 1BJ Hants England

Fitting piecewise affine models to data points is a pervasive task in many scientific disciplines. In this work, we address the k-Piecewise Affine Model Fitting with Piecewise linear Separability problem (k-PAMF-PLS) where, given a set of m points {a(1),...,a(m)} subset of R-n and the corresponding observations {b(1),...,b(m)} subset of R, we have to partition the domain R-n into k piecewise linearly (or affinely) separable subdomains and to determine an affine submodel (i.e., an affine function) for each of them so as to minimize the total linear fitting error w.r.t. the observations b(i). To solve k-PAMF-PLS to optimality, we propose a mixed-integer linear programming (MILP) formulation where symmetries are broken by separating shifted column inequalities. For medium-to-large scale instances, we develop a four-step heuristic involving, at each iteration, a point reassignment step based on the identification of critical points and a domain partition step based on multicategory linear classification. Differently from traditional approaches proposed in the literature for similar fitting problems, in both our exact and heuristic methods the domain partitioning and submodel fitting aspects are taken into account simultaneously. Computational experiments on real-world and structured randomly generated instances show that, with our MILP formulation with symmetry breaking constraints, we can solve to proven optimality many small-size instances. Our four-step heuristic turns out to provide close-to-optimal solutions for the small size instances, while allowing to tackle instances of much larger size. The experiments also show that the combined impact of the main features of our heuristic is quite substantial when compared to standard variants not including them. We conclude the paper with an application to the identification of dynamical, piecewise affine systems, for which we obtain promising results of comparable quality with those achieved with state-of-the-art methods

关键词： Data mining Piecewise affine model fitting mixed-integer linear programming Heuristics

来源：评论

学校读者我要写书评

暂无评论

A shortcut model for energy efficient water network synthesis

引用

APPLIED THERMAL ENGINEERING 2016年 96卷 88-91页

作者： Liang, Yingzong Hui, Chi-Wai Hong Kong Univ Sci & Technol Dept Chem & Biomol Engn Kowloon Hong Kong Peoples R China

This paper presents a shortcut model for energy efficient water network synthesis with single contaminant. The proposed model is based on the idea of reducing repeated heating and cooling proposed by Feng et al. [9]. To avoid sub-optimum that can be generated from Feng's model, the proposed model only minimizes the number of temperature 'valleys' instead of the total number of 'peaks and valleys' of the water network. With the new formulation, the proposed model not only guarantees global optimum but also becomes much easier to be solved. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Water allocation network Heat integration mixed-integer linear programming

来源：评论

学校读者我要写书评

暂无评论

A novel two-model based approach for optimal scheduling in CSP plants

引用

SOLAR ENERGY 2016年 126卷 73-92页

作者： Jesus Vasallo, Manuel Manuel Bravo, Jose Univ Huelva Dept Elect Engn Comp Syst & Automat Carretera Palos de La Frontera S-N Palos De La Frontera 21819 Huelva Spain

Thermal energy storage (TES) systems allow concentrated solar power (CSP) producers to participate in a day-ahead market. Then, the optimal power scheduling problem can be posed, whose objective is the maximisation of profits derived from electricity sales. Most papers in literature use a mixed-integer linear programming (MILP) approach to solve this type of problems. This paper proposes a novel approach based on the use of two models: a detailed model and a MILP model. This approach combines MILP capabilities and the accuracy of a detailed model. The proposed approach is applied to a 50 MW parabolic-trough-collector based CSP plant with molten-salt-based TES. A detailed model available in literature and validated against operating plant data is used, but some improvements are included for its use in optimal scheduling problems. Moreover, the MILP model was developed to adjust as much as possible to the features of the detailed model. The improvements regarding other scheduling strategies for a specific example are shown. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Concentrating solar power plant Thermal energy storage Electricity market Optimized operation strategy Parabolic trough collector mixed-integer linear programming

来源：评论

学校读者我要写书评

暂无评论

linear approximated formulation of AC optimal power flow using binary discretisation

引用

IET GENERATION TRANSMISSION & DISTRIBUTION 2016年第5期10卷 1117-1123页

作者： Akbari, Tohid Bina, Mohammad Tavakoli KN Toosi Univ Technol Fac Elect Engn Tehran Iran

This study presents a novel linear approximated methodology for full alternating current-optimal power flow (AC-OPF). The AC-OPF can provide more precise and real picture of full active and reactive power flow modelling, along with the voltage profile of buses compared to the commonly used direct current-optimal power flow. While the AC-OPF is a non-linear programming problem, this can be transformed into a mixed-integer linear programming environment by the proposed model without loss of accuracy. The global optimality of the solution for the approximated model can be guaranteed by existing algorithms and software. The numerical results and simulations which represent the effectiveness and applicability of the proposed model are given and completely discussed in this study.

关键词： load flow nonlinear programming integer programming linear programming linear approximated formulation AC optimal power flow binary discretisation linear approximated methodology full alternating current-optimal power flow AC-OPF reactive power flow modelling voltage profile direct current-optimal power flow nonlinear programming problem mixed-integer linear programming

来源：评论

学校读者我要写书评

暂无评论

Robust Optimization for Strategic Energy Planning

引用

INFORMATICA 2016年第3期27卷 625-648页

作者： Moret, Stefano Bierlaire, Michel Marechal, Francois Ecole Polytech Fed Lausanne Ind Proc & Energy Syst Engn Grp IPESE CH-1015 Lausanne Switzerland Ecole Polytech Fed Lausanne Transport & Mobil Lab CH-1015 Lausanne Switzerland

Long-term planning for energy systems is often based on deterministic economic optimization and forecasts of fuel prices. When fuel price evolution is underestimated, the consequence is a low penetration of renewables and more efficient technologies in favour of fossil alternatives. This work aims at overcoming this issue by assessing the impact of uncertainty on energy planning decisions. A characterization of uncertainty in energy systems decision-making is performed. Robust optimization is then applied to a mixed-integer linear programming problem, representing the typical trade-offs in energy planning. It is shown that in the uncertain domain investing in more efficient and cleaner technologies can be economically optimal.

关键词： energy planning robust optimization uncertainty characterization mixed-integer linear programming

来源：评论

学校读者我要写书评

暂无评论

A joint chance-constrained programming approach for call center workforce scheduling under uncertain call arrival forecasts

引用

COMPUTERS & INDUSTRIAL ENGINEERING 2016年 96卷 16-30页

作者： Excoffier, M. Gicquel, C. Jouini, O. Univ Paris 11 Rech Informat Lab Campus OrsayBatiment 650 F-91405 Orsay France Ecole Cent Paris Lab Genie Ind F-92290 Chatenay Malabry France

We consider a workforce management problem arising in call centers, namely the shift-scheduling problem. It consists in determining the number of agents to be assigned to a set of predefined shifts so as to optimize the trade-off between manpower cost and customer quality of service. We focus on explicitly taking into account in the shift-scheduling problem the uncertainties in the future call arrival rates forecasts. We model them as independent random variables following a continuous probability distribution. The resulting stochastic optimization problem is handled as a joint chance-constrained program and is reformulated as an equivalent large-size mixed-integer linear program. One key point of the proposed solution approach is that this reformulation is achieved without resorting to a scenario generation procedure to discretize the continuous probability distributions. Our computational results show that the proposed approach can efficiently solve real-size instances of the problem, enabling us to draw some useful managerial insights on the underlying risk-cost trade-off. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Personnel planning Call center shift scheduling Customer abandonment Stochastic programming Probabilistic constraints mixed-integer linear programming

来源：评论

学校读者我要写书评

暂无评论

Stochastic Unit Commitment in Isolated Systems With Renewable Penetration Under CVaR Assessment

引用

IEEE TRANSACTIONS ON SMART GRID 2016年第3期7卷 1356-1367页

作者： Asensio, Miguel Contreras, Javier Univ Castilla La Mancha ETS Ingenieros Ind E-13071 Ciudad Real Spain

Isolated regions and islands are facing imported fossil-fuel dependency, higher electricity prices, and vulnerability to climate change. At the same time, they are increasing their renewable penetration and, therefore, risk for electric utilities. Integrating stochastic energy resources in noninterconnected systems may take advantage of an intelligent and optimized risk-averse unit commitment (UC) model. This paper presents a two-stage stochastic UC model with high renewable penetration including reserve requirements for the efficient management of uncertainty. In order to account for the uncertainty around the true outcomes of load, wind, and photovoltaic (PV) generation, a minimum conditional value at risk term has been included in the model formulation. A stochastic measure of the value of the stochastic solution is used to evaluate the benefits of using stochastic programming. The model considers the need for reserves dependent on the forecasting horizon and the amount of renewable generation. Active power demand, and wind and PV generations are considered as probability distribution functions. The model is applied to the Lanzarote-Fuerteventura system in the Canary Islands, Spain, and Crete, Greece.

关键词： Conditional value at risk (CVaR) mean-risk value of the stochastic solution (MRVSS) mixed-integer linear programming risk aversion two-stage stochastic programming unit commitment (UC)

来源：评论

学校读者我要写书评

暂无评论

A robust optimization model for agile and build-to-order supply chain planning under uncertainties

引用

ANNALS OF OPERATIONS RESEARCH 2016年第2期240卷 435-470页

作者： Lalmazloumian, Morteza Wong, Kuan Yew Govindan, Kannan Kannan, Devika Univ Teknol Malaysia Fac Mech Engn Dept Mfg & Ind Engn Skudai Malaysia Univ Southern Denmark Dept Econ & Business Odense Denmark Aalborg Univ Dept Mech & Mfg Engn DK-2450 Copenhagen Denmark

Supply chain planning as one of the most important processes within the supply chain management concept, has a great impact on firms' success or failure. This paper considers a supply chain planning problem of an agile manufacturing company operating in a build-to-order environment under various kinds of uncertainty. An integrated optimization approach of procurement, production and distribution costs associated with the supply chain members has been taken into account. A robust optimization scenario-based approach is used to absorb the influence of uncertain parameters and variables. The formulation is a robust optimization model with the objective of minimizing the expected total supply chain cost while maintaining customer service level. The developed multi-product, multiperiod, multi-echelon robust mixed-integer linear programming model is then solved using the CPLEX optimization studio and guidance related to future areas of research is given.

关键词： Agile manufacturing Build-to-order Supply chain planning Robust optimization mixed-integer linear programming

来源：评论

学校读者我要写书评

暂无评论

Using cross-docking operations in a reverse logistics network design: a new approach

引用

PRODUCTION ENGINEERING-RESEARCH AND DEVELOPMENT 2016年第2期10卷 175-184页

作者： Kheirkhah, Amirsaman Rezaei, Saeid Bu Ali Sina Univ Sch Engn Dept Ind Engn Hamadan Iran

Increasing development of competitive market has forced organizations to make great efforts in supplying, production and distribution of goods in their company so that they are capable of responding the customers different needs at the minimum delivery time and lowest cost. Cross-docking is a practical strategy in distribution cycle which has significantly attracted the attention of experts and industrialists in different areas. In this paper, the problem of designing a multi-echelon reverse logistics network with applying cross-docking centers is presented-as the first attempt to propose the new approach of using cross-docking centers in reverse logistics network. In this regard, a mixed-integer linear programming is utilized to model the problem for the goals of increasing shipment rate, decreasing fixed, variable costs and better management of returned products. Finally, the validation and sensitivity analysis are done by using the GAMS software. Considered the above requirements, the model facilitates objective-oriented reverse logistic performance.

关键词： Reverse logistics Cross-docking operations Multi-echelon logistics network design mixed-integer linear programming

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：