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MARITIME ECONOMICS & LOGISTICS 2014年第4期16卷 418-435页

作者： Plum, Christian Edinger Munk Jensen, Peter Neergaard Pisinger, David Maersk Line DK-1098 Copenhagen K Denmark Maersk Oil Trading DK-1098 Copenhagen K Denmark Tech Univ Denmark DK-2800 Lyngby Denmark

The cost for bunker fuel represents a major part of the daily running costs of liner shipping vessels. The vessels, sailing on a fixed roundtrip of ports, can lift bunker at these ports, having differing and fluctuating prices. The stock of bunker on a vessel is subject to a number of operational constraints such as capacity limits, reserve requirements and sulphur content. Contracts are often used for bunker purchasing, ensuring supply and often giving a discounted price. A contract can supply any vessel in a period and port, and is thus a shared resource between vessels, which must be distributed optimally to reduce overall costs. The Bunker Purchasing with Contracts Problem has been formulated as a mixed integer programme, which has been Dantzig-Wolfe decomposed. To solve it, a novel column generation algorithm has been developed. The algorithm has been run on a series of real-world instances with up to 500+ vessels and 500+ contracts, and provide near optimal solutions. This makes it possible for a major liner shipping company to plan bunker purchasing on a global level, and provides an efficient tool for assessing new contracts.

关键词： bunker purchasing liner shipping mathematical programming maritime optimization decomposition methods mixed integer programming

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SOLID-STATE LIGHT SIMULATOR FOR HORTICULTURAL APPLICATIONS 14

SOLID-STATE LIGHT SIMULATOR FOR HORTICULTURAL APPLICATIONS

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14th Brazilian Power Electronics Conference (COBEP)

作者： Martin, Klaus T. de Araujo, Olinto C. B. Bonaldo, Saul A. da Silva, Marcelo F. Univ Fed Santa Maria Elect & Computat Syst Res & Dev Grp GSEC Santa Maria RS Brazil

ISBN: (纸本)9781509062485

This work presents a flexible light simulator designed to reproduce precise conditions of both spectrum and intensity of light. The system consists of a combination of different LEDs defined by an optimized selection method. Buck converters under current-mode control are used to achieve the independent control of each LED model. Independent control of all light sources allows the possibility to vary intensity and spectral distribution of the light. As an example of application, an LED module is designed and implemented to meet the midday sunlight spectrum.

关键词： Light emitting diodes spectrum simulation solid-state-lighting mixed integer programming

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Nutmeg: a MIP and CP Hybrid Solver Using Branch-and-Check

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Operations Research Forum 2020年第3期1卷 1-27页

作者： Lam, Edward Gange, Graeme Stuckey, Peter J. Van Hentenryck, Pascal Dekker, Jip J. Department of Data Science and Artificial Intelligence Faculty of Information Technology Monash University Melbourne VIC Australia H. Milton Stewart School of Industrial and Systems Engineering Georgia Institute of Technology Atlanta GA United States

This paper describes the implementation of Nutmeg, a solver that hybridizes mixed integer linear programming and constraint programming using the branch-and-cut style of logic-based Benders decomposition known as branch-and-check. Given a high-level constraint programming model, Nutmeg automatically derives a mixed integer programming master problem that omits global constraints with weak linear relaxations, and a constraint programming subproblem identical to the original model. At every node in the branch-and-bound search tree, the linear relaxation computes dual bounds and proposes solutions, which are checked for feasibility of the omitted constraints in the constraint programming subproblem. In the case of infeasibility, conflict analysis generates Benders cuts, which are appended to the linear relaxation to cut off the candidate solution. Experimental results show that Nutmeg’s automatic decomposition outperforms pure constraint programming and pure mixed integer programming on problems known to have successful implementations of logic-based Benders decomposition, but performs poorly on general problems, which lack specific decomposable structure. Nonetheless, Nutmeg outperforms the standalone approaches on one problem with no known decomposable structure, providing preliminary indications that a hand-tailored decomposition for this problem could be worthwhile. On the whole, Nutmeg serves as a valuable tool for novice modelers to try hybrid solving and for expert modelers to quickly compare different logic-based Benders decompositions of their problems. © 2020, Springer Nature Switzerland AG.

关键词： Branch-and-check Conflict analysis Constraint programming Dual bound Hybridization Lazy clause generation Linear constraints Logic-based Benders decomposition mixed integer programming Nogood

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Optimal coordination of directional overcurrent relay coordination

Optimal coordination of directional overcurrent relay coordi...

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IEEE-Power-Engineering-Society General Meeting

作者： Zeineldin, H El-Saadany, EF Salama, MA Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

ISBN: (纸本)078039156X

Directional overcurrent relays are used to protect interconnected power systems and looped distribution systems. Several techniques and formulations have been proposed to solve the directional overcurrent relay problem. In this paper, the proposed formulations for relay coordination problem are discussed. The protective relay coordination problem is reformulated to take into account the discrete pickup current values. The directional overcurrent relay coordination problem is formulated as a mixed integer-programming problem. The problem is solved using the OSL solver of the General Algebraic Modeling System (GAMS).

关键词： mixed integer programming overcurrent relay power system protection protection coordination

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Toward digital twins' workload allocation on clouds with low-cost microservices streaming interaction

Toward digital twins' workload allocation on clouds with low...

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Ivannikov Ispras Open Conference (ISPRAS)

作者： Tchernykh, Andrei Facio-Medina, Adrian Pulido-Gaytan, Bernardo Rivera-Rodriguez, Raul Cortes-Mendoza, Jorge M. Radchenko, Gleb Babenko, Mikhail Chernykh, Igor Kulikov, Igor Nesmachnow, Sergio Ivannikov Inst Syst Programming Moscow Russia CICESE Res Ctr Ensenada Baja California Mexico South Ural State Univ Chelyabinsk Russia North Caucasus Fed Univ Stavropol Russia ICMMG SB RAS Novosibirsk Russia Univ Republica Montevideo Uruguay

ISBN: (纸本)9781665412919

A Digital Twin (DT) is a set of computational models representing real-time physical objects and processes in a digital world. The increasing adoption of this paradigm by the major industrial equipment vendors to simulate real-time working conditions and perform smart decision-making, established the Smart Factory Digital Twins architectures, where a set of DTs published as microservices interact with each other exchanging information by streaming technology. In this sense, a fundamental problem consists of selecting adequate computational resources to simulate the physical objects. In an Infrastructure as a Service (IaaS) cloud for DTs, the allocation focuses on distributing the jobs of the set into the virtual machine instances in a way that computational resources demand is satisfied and the cost is minimized In this paper, we propose a set of algorithms based on heuristics, metaheuristics, and mixed integer programming to find low-cost solutions. The performance of algorithms is evaluated using Amazon EC2 instances and DT jobs with randomly generated bandwidth, memory, and processor requirements. The experimental results show that the proposed approaches based on bin packing, genetic algorithms, partition, filtering, set coverage, and branch and bound strategies present a competitive performance in the workload allocation of the computational set of jobs of a DT into an IaaS cloud environment. Our allocation heuristic-based techniques allow considerable cost savings in medium and large periods concerning standard approaches such as local search.

关键词： Instance Provisioning Digital Twin Smart Factory EC2 mixed integer programming Evolutionary Algorithms Metaheuristics

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A Fast Web Service Selection Approach

A Fast Web Service Selection Approach

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International Conference on Computing, Information and Control (ICCIC 2011)

作者： Li, Jinglin Wang, Shangguang Sun, Qibo Yang, Fangchun Beijing Univ Posts & Telecommun State Key Lab Networking & Switching Technol Beijing 100088 Peoples R China

ISBN: (纸本)9783642240096;9783642240102

Fast web service selection approach is crucial for seamless and dynamic integration of e-business applications. However, since existing service selection approaches take up a lot of time, this make service selection out of time control. In this paper, we propose a fast web service selection (FWSS) approach for service composition system in e-business. In FWSS, only those services that fit to the context of users are valid candidates for the composition. and then mixed integer programming is used to find the most suitable service from above services. Experimental results show that our approach can fast perform service selection for web service composition.

关键词： Web service Service selection QoS Hierarchical Fuzzy System mixed integer programming

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Lagrange Heuristic Algorithm Incorporated with Decomposition Strategy for Green Multi-depot Heterogeneous-Fleet Vehicle Routing Problem 19th

Lagrange Heuristic Algorithm Incorporated with Decomposition...

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19th International Conference on Advanced Intelligent Computing Technology and Applications (ICIC)

作者： Xu, Linhao Qian, Bin Hu, Rong Yu, Naikang Jin, Huaiping Kunming Univ Sci & Technol Fac Informat Engn & Automat Kunming 650500 Yunnan Peoples R China

ISBN: (纸本)9789819947607;9789819947614

Aiming at the green multi-depot heterogeneous-fleet vehicle routing problem (GMDHFVRP), a mixed integer programming model (MIP) was established to minimize the total cost, and a Lagrange heuristic algorithm incorporated with decomposition strategy (LHA_DS) was proposed to solve it. First, the original problem is decomposed into a number of vehicle sub-problems by relaxing the complex constraints. At the same time, the distance-based K-means clustering method is used to allocate service customer sets for each parking lot, and the surrogate subgradient method is used to solve the sub-problems to update the lagrange multiplier;Secondly, in order to obtain a better initial feasible solution, a repair strategy based on greedy idea is designed to repair the problem relaxation solution to obtain a better solution, and a neighborhood search method to determine the operation order is designed to optimize the feasible solution. Finally, the effectiveness of LHA_DS in solving GMDHFVRP is verified by simulation experiments.

关键词： green multi-depot heterogeneous-fleet vehicle routing problem mixed integer programming Lagrange heuristic surrogate subgradient

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Developing Next Generation Electricity Market Clearing Optimization Software

Developing Next Generation Electricity Market Clearing Optim...

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IEEE-Power-and-Energy-Society General Meeting (PESGM)

作者： Chen, Yonghong Wang, Fengyu Wan, Jie Pan, Feng MISO Energy Carmel IN 46032 USA GE Grid Solut Redmond WA USA Pacific Northwest Natl Lab Seattle WA USA

ISBN: (纸本)9781538677032

Electricity markets have brought significant benefit to the society. The core of the market clearing system is Security Constrained Unit Commitment (SCUC) and Security Constrained Economic Dispatch (SCED). This paper first shares the experience from Midcontinent Independent System Operator (MISO) and GE Grid Solution to improve MISO market clearing software performance to meet the needs of market development and business requirement. It then introduces the research and development on next generation market clearing software, including the ARPA-E project to develop high performance computer based optimization engines, to position RTOs/ISOs for future industry evolution.

关键词： Electricity market mixed integer programming security constrained unit commitment security constrained economic dispatch

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A Two-Stage MIP Based Optimization Framework for Unit Commitment and Energy Pricing

A Two-Stage MIP Based Optimization Framework for Unit Commit...

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Power and Energy Conference at Illinois

作者： Xia, Yu Marwali, Muhammad Chow, Joe H. Rensselaer Polytech Inst Dept Elect Comp & Syst Engn Troy NY 12180 USA New York Independent Syst Operator Rensselaer NY 13699 USA

ISBN: (纸本)9781479979493

Power system unit commitment (UC) is a non-convex NP-complete problem, which is very complex to solve on a large scale. Solution methods for the UC problem have been explored, with Lagrangian relaxation (LR) being one of the most popular approaches in practice. The significant reduction in numerical solution times of commercial mixed integer programming (MIP) solvers makes transitioning from LR to MIP possible. This paper presents a MIP based two-stage optimization approach for solving the UC problem as well as the energy price. The proposed framework has been implemented using MATLAB and tested on two test power systems.

关键词： mixed integer programming Lagrangian relaxation unit commitment energy pricing

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Integration of Process Planning and Scheduling with Sequence Dependent Setup Time: A Case Study from Electrical Wires and Power Cable Industry 3rd

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3rd International Conference on Modelling, Computation and Optimization in Information Systems and Management Sciences (MCO)

作者： Altarazi, Safwan Yasin, Omar Appl Sci Private Univ Dept Mech & Ind Engn Amman Jordan German Jordanian Univ Dept Ind Engn Amman Jordan

ISBN: (纸本)9783319181677;9783319181660

This paper addresses the integration of process planning and scheduling (IPPS) with sequence dependent setup times for a case from the electrical wires and power cables industry. While the IPPS problem has been a subject of researchers' attention in recent years, majority of research in this field neglect setup time or assume it as a part of processing time. The objective is to simultaneously select the most feasible process plan and schedule with minimum makespan. The problem is modeled as a mixed integer linear programming problem and an example is presented to demonstrate the applicability and effectiveness of the proposed modeling approach.

关键词： Integrated process planning and scheduling Sequence dependent setup time Electrical Wires and Power Cable Industry mixed integer programming

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