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Network interdiction via a Critical Disruption Path: Branch-and-Price algorithms

COMPUTERS & OPERATIONS RESEARCH 2013年第11期40卷 2689-2702页

作者： Granata, Donatella Steeger, Gregory Rebennack, Steffen CNR Inst Applicat Calculus Mauro Picone Naples Italy Colorado Sch Mines Div Econ & Business Golden CO 80401 USA

This paper presents an innovative approach to maximally disconnect a given network. More specifically, this work introduces the concept of a Critical Disruption Path, a path between a source and a destination vertex whose deletion minimizes the cardinality of the largest remaining connected component. Network interdiction models seek to optimally disrupt network operations. Existing interdiction models disrupt network operations by removing vertices or edges. We introduce the first problem and formulation that optimally fragments a network via interdicting a path. Areas of study in which this work can be applied include transportation and evacuation networks, surveillance and reconnaissance operations, anti-terrorism activities, drug interdiction, and counter human-trafficking operations. In this paper, we first address the complexity associated with the Critical Disruption Path problem, and then provide a mixed-integer linear programming formulation for finding its optimal solution. Further, we develop a tailored Branch-and-Price algorithm that efficiently solves the Critical Disruption Path problem. We demonstrate the superiority of the developed Branch-and-Price algorithm by comparing the results found via our algorithm with the results found via the monolith formulation. In more than half of the test instances that can be solved by both the monolith and our Branch-and-Price algorithm, we outperform the monolith by two orders of magnitude. (c) 2013 Elsevier Ltd. All rights reserved.

关键词： Network interdiction mixed-integer linear programming NP-completeness Branch-and-Price Cuts

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Achieving energy self-sufficiency by integrating renewables into companies' supply networks

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ENERGY 2013年 55卷 46-57页

作者： Kiraly, Annamaria Pahor, Bojan Kravanja, Zdravko Perutnina Ptuj Dd SI-2250 Ptuj Slovenia Univ Maribor Fac Chem & Chem Engn SI-2000 Maribor Slovenia

The aim of this contribution was to present the integration of renewables into companies' supply-networks at regional level in order to maximise the self-sufficiencies of their energy supplies. This concerns companies' activities from the use of natural resources to supplying their final products to the customers being interlinked with their regional networks. A MILP model (mixed-integer linear programming) has been developed for the synthesis of companies' supply-networks utilising different types of renewables as sources for the companies' energy supplies, and embedded into the MILP model, previously developed by authors, for the synthesis of regional biomass production and supply networks. The integrated synthesis model was applied to an existing large-scale meat company. The potential renewable energy sources, which are located within companies surrounding region are solar, biomass, organic and animal wastes. The result indicates that by sufficient integration of renewables into companies' supply networks, profitable and yet energy self-sufficient solutions can be obtained. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： Companies supply-chain Regional supply-network optimisation Renewables Energy self-sufficiency mixed-integer linear programming

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An approach to optimization of airport taxiway scheduling and traversal under uncertainty

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART G-JOURNAL OF AEROSPACE ENGINEERING 2013年第G2期227卷 273-284页

作者： Anderson, Ross Milutinovic, Dejan Univ Calif Santa Cruz Santa Cruz CA 95060 USA

Airport runways and taxiways have been identified as a key source of system-wide congestion and delay in the over-strained commercial air traffic system. To combat this growing problem, we present a novel approach for taxiway scheduling and traversal. Aircraft must traverse a taxiway, represented by a graph, from gates to their respective runways and arrive at their scheduled times while adhering to safety separation constraints. We describe a combinatorial mixed-integer linear program to determine the push-back time windows, aircraft speeds, stopping times, and in particular, traversal paths for a given graph and an imposed flight schedule as part of a single optimization problem. Safety and scheduling constraints are made robust to probabilistic deviations from the prescribed schedule and aircraft motion, and multiple objective functions are considered to examine the trade-off between taxi times and the probability of safety separation violation. Several scenarios are presented to demonstrate improvements gained from the method and possible uses for this approach.

关键词： Taxiway optimization airport scheduling mixed-integer linear programming

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Hourly Demand Response in Day-Ahead Scheduling Considering Generating Unit Ramping Cost

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IEEE TRANSACTIONS ON POWER SYSTEMS 2013年第3期28卷 2446-2454页

作者： Wu, Hongyu Shahidehpour, Mohammad Khodayar, Mohammad E. IIT Dept Elect & Comp Engn Chicago IL 60616 USA

This paper proposes a day-ahead scheduling model in which the hourly demand response (DR) is considered to reduce the system operation cost and incremental changes in generation dispatch when the ramping cost of thermal generating units is considered as penalty in day-ahead scheduling problem. The power output trajectory of a thermal generating unit is modeled as a piecewise linear function. The day-ahead scheduling is formulated as a mixed-integer quadratically constrained programming (MIQCP) problem with quadratic energy balance constraint, ramping cost, and DR constraints. A Lagrangian relaxation (LR) based method is applied to solve this problem. Numerical tests are conducted on a 6-bus system and the modified IEEE 118-bus system. The results demonstrate the merits of the proposed scheduling model as well as the impact of introducing ramping costs as penalty and DR as incentives in the day-ahead scheduling of power systems.

关键词： Demand response generating unit ramping cost Lagrangian relaxation mixed-integer linear programming security constrained unit commitment

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A mathematical model and a heuristic approach for periodic material delivery in lean production environment

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2013年第5-8期69卷 977-992页

作者： Kilic, Huseyin Selcuk Durmusoglu, Mehmet Bulent Marmara Univ Dept Ind Engn TR-34722 Istanbul Turkey Istanbul Tech Univ Dept Ind Engn TR-34367 Istanbul Turkey

One of the important design elements for a good production system is material handling. In cases where it is not well-designed, it can be the bottleneck in the system. Moreover, it can cause a lot of wastes such as waiting time, idle time, and excessive transportation and cost. In this study, material handling in lean-based production environments is taken into account. Depending on the lean structure of the production systems such as being pull-based, smooth, and repetitive, delivering the materials to the stations periodically becomes important. At this point, milk-run trains are highly used in real applications since they enable the handling of required amount of materials on a planned basis. With this study, it is aimed to develop a specific model for milk-run trains which travel periodically in the production environment on a predefined route in equal cycle times with the aim of minimizing work-in-process and transportation costs. Since the milk-run trains having equal cycle times start their tours at the same time intervals, it becomes simple to manage them. For this reason, they are used in lean production systems where level scheduling is performed. The developed model is based on mixed-integer linear programming, and since it is difficult to find the optimum solution due to the combinatorial structure of the problem, a novel heuristic approach is developed. A numerical example is provided so as to show the applicability of the mathematical model and the heuristic approach.

关键词： In-plant logistics Milk-run distribution Lean production mixed-integer linear programming Heuristic approach

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The importance of economies of scale, transport costs and demand patterns in optimising hydrogen fuelling infrastructure: An exploration with SHIPMod (Spatial hydrogen infrastructure planning model)

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2013年第26期38卷 11189-11201页

作者： Agnolucci, Paolo Akgul, Ozlem McDowall, William Papageorgiou, Lazaros G. UCL UCL Inst Sustainable Resources London WC1H 0NN England UCL Ctr Proc Syst Engn London WC1E 7JE England

Hydrogen is widely recognised as an important option for future road transportation, but a widespread infrastructure must be developed if the potential for hydrogen is to be achieved. This paper and related appendices which can be downloaded as Supplementary material present a mixed-integer linear programming model (called SHIPMod) that optimises a hydrogen supply chains for scenarios of hydrogen fuel demand in the UK, including the spatial arrangement of carbon capture and storage infrastructure. In addition to presenting a number of improvements on past practice in the literature, the paper focuses attention on the importance of assumptions regarding hydrogen demand. The paper draws on socio-economic data to develop a spatially detailed scenario of possible hydrogen demand. The paper then shows that assumptions about the level and spatial dispersion of hydrogen demand have a significant impact on costs and on the choice of hydrogen production technologies and distribution mechanisms. Copyright (C) 2013, The Authors. Published by Elsevier Ltd. All rights reserved.

关键词： Hydrogen supply chains mixed-integer linear programming Infrastructure optimisation modelling

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Commercial territory design planning with realignment and disjoint assignment requirements

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OMEGA-INTERNATIONAL JOURNAL OF MANAGEMENT SCIENCE 2013年第3期41卷 525-535页

作者： Rios-Mercado, Roger Z. Fabian Lopez-Perez, J. Univ Autonoma Nuevo Leon Grad Program Syst Engn San Nicolas De Los Garza 66450 NL Mexico Univ Autonoma Nuevo Leon Grad Program Management Sci CEDEEM San Nicolas De Los Garza 66450 NL Mexico

A territory design problem motivated by a bottled beverage distribution company is addressed. The problem consists of finding a partition of the entire set of city blocks into a given number of territories subject to several planning criteria. Each unit has three measurable activities associated to it, namely, number of customers, product demand, and workload. The plan must satisfy planning criteria such as territory compactness, territory balancing with respect to each of the block activity measures, and territory connectivity, meaning that there must exist a path between any pair of units in a territory totally contained in it. In addition, there are some disjoint assignment requirements establishing that some specified units must be assigned to different territories, and a similarity with existing plan requirement. An optimal design is one that minimizes a measure of territory dispersion and similarity with existing design. A mixed-integer linear programming model is presented. This model is unique in the commercial territory design literature as it incorporates the disjoint assignment requirements and similarity with existing plan. Previous methods developed for related commercial districting problems are not applicable. A solution procedure based on an iterative cut generation strategy within a branch-and-bound framework is proposed. The procedure aims at solving large-scale instances by incorporating several algorithmic strategies that helped reduce the problem size. These strategies are evaluated and tested on some real-world instances of 5000 and 10,000 basic units. The empirical results show the effectiveness of the proposed method and strategies in finding near optimal solutions to these very large instances at a reasonably small computational effort. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： Bottled beverage distribution Commercial districting mixed-integer linear programming Branch-and-bound method Heuristics

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Tight and Compact MILP Formulation of Start-Up and Shut-Down Ramping in Unit Commitment

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IEEE TRANSACTIONS ON POWER SYSTEMS 2013年第2期28卷 1288-1296页

作者： Morales-Espana, German Latorre, Jesus M. Ramos, Andres Univ Pontificia Comillas Sch Engn ICAI Inst Res Technol IIT Madrid Spain

This paper presents a mixed-integer linear programming (MILP) formulation of start-up (SU) and shut-down (SD) power trajectories of thermal units. Multiple SU power-trajectories and costs are modeled according to how long the unit has been offline. The proposed formulation significantly reduces the computational burden in comparison with others commonly found in the literature. This is because the formulation is 1) tighter, i.e., the relaxed solution is nearer to the optimal integer solution;and 2) more compact, i.e., it needs fewer constraints, variables and nonzero elements in the constraint matrix. For illustration, the self-unit commitment problem faced by a thermal unit is employed. We provide computational results comparing the proposed formulation with others found in the literature.

关键词： mixed-integer linear programming start-up and shut-down ramps thermal units unit commitment

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An Optimization Model to Integrate Forest Plantations and Connecting Corridors

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FOREST SCIENCE 2013年第6期59卷 661-669页

作者： Moreira, Jose Mauro M. A. P. Rodriguez, Luiz C. E. Caixeta-Filho, Jose V. Embrapa Forestry Colombo Parana Brazil Univ Sao Paulo Dept Forest Sci BR-05508 Sao Paulo Brazil Univ Sao Paulo Dept Econ Adm & Sociol BR-05508 Sao Paulo Brazil

Spatial and environmental constraints in forest management optimization problems have become a challenge to researchers working with forest management planning optimization models, mainly because of the combinatorial nature of these problems. Forest managers in Brazil are often faced with the need to connect native forest fragments through the management of the landscape that surrounds them. The objective of this article is to develop a mixed-integer linear programming model that guarantees minimal connectivity among fragmented natural areas while maximizing the profit or the production of the managed industrial forest plantations. The corridors are formed by industrial forest stands with specific characteristics defined by the forest manager. In this article, connectivity among fragments was inserted as a Steiner net in a type I harvest-scheduling model. The resulting net formulation has an integer number of origins, destinations, and arc capacities, which allows for the basic variables to produce integer values, even when variables defining flows in each arc are defined as continuous. For the case study, the opportunity cost of creating the corridors was estimated at approximately 0.051% of the objective function value obtained for the model without connectivity.

关键词： ecological corridors mixed-integer linear programming spatial restrictions forest management forest economics

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Forecasting flexibility in electricity demand with price/consumption volume signals

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ELECTRIC POWER SYSTEMS RESEARCH 2013年 95卷 200-205页

作者： Gorria, C. Jimeno, J. Laresgoiti, I. Lezaun, M. Ruiz, N. Univ Pais Vasco UPV EHU Dept Appl Math Stat & Operat Res Leioa 48940 Spain Tecnalia Energy Unit Derio 48160 Spain

The introduction of renewable energy sources, particularly wind power, is limited by their dependence on weather conditions and by the difficulty of storing surplus energy for use at times when production is low. One effective way of tackling the energy storage problem is to minimise the need for storage, i.e. to switch from a system based on producing electricity in response to the unpredictable whims of demand to one in which consumption adapts to supply. Demand can be managed indirectly via the sending of price/consumption volume signals. This paper presents a mathematical model for forecasting the aggregated electricity demand of a group of domestic consumers signed up to an incentive-based demand management programme. Under this programme consumers receive signals that offer financial incentives for limiting their volume of consumption at time intervals when system peak demand is forecast. The resulting optimisation model is a mixed-integer linear programming problem implemented in JAVA and solved using free software. This model is applied to a case study in which the objective is to limit consumption by a population of 15932 consumers from 15:00 to 17:45 on a specific summer day. The responses to two different incentive amounts are shown. (c) 2012 Elsevier B.V. All rights reserved.

关键词： Electricity demand Demand management Optimisation mixed-integer linear programming

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