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作者： Chakrabarty, Nayan Ohio University

学位级别：硕士

There are many factors such as, space constraint, service level, and nursing personnel satisfaction that makes the hospital supply chain more complex than the traditional supply chain. Effective inventory management can contribute to a significant amount of cost reduction. This thesis proposed a new multiple Kanban card system for hospital nursing units that will replace the two-bin system into the multiple Kanban card system. The new system helps to reduce the overall inventory cost. For the new system, along with restocking cost, inventory holding cost, and shortage cost, an additional Kanban cards retrieve cost is included. A mixed-integer programming model is developed for the new system. To validate the model, both small-scale and large-scale problems are solved using solving constraint integer programs (SCIP) solver with AMPL software. A comparison is made between the two Kanban card system and the multiple Kanban card system in terms of overall inventory cost. The result showed that 25% cost reduction possible for multiple Kanban card system. The characteristics of the objective function of this model are further analyzed by varying the service level. The result showed that using the multiple Kanban card system, a high service level can be achieved at a minimum cost that is 27% lower than the cost for using two Kanban card system.

关键词： Industrial Engineering Healthcare inventory system Optimization mixed integer programming

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Problema de redimensionamento de lotes para máquinas paralelas em ambientes de usinagem

Problema de redimensionamento de lotes para máquinas parale...

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作者： Leandrin, Matheus Artioli Universidade Estadual Paulista

Este trabalho aborda o Problema de Redimensionamento de Lotes (PRL) capacitado, com múltiplos produtos e máquinas paralelas. O redimensionamento de lotes é uma variação do problema de dimensionamento de lotes que pode ser identificado em sistemas produtivos com elevada taxa de interrupções, como quebras, refugos, entre outros, fazendo com que o plano de produção seja prejudicado, necessitando de atualizações a medida que ocorrem as interrupções. São considerados três parâmetros de interrupção: manutenção corretiva, mão de obra insuficiente e indisponibilidade de matéria-prima. É permitido o atendimento da demanda nos períodos com atrasos e utilização de hora extra. O problema tem por objetivo minimizar os custos de preparação, estoque, atraso e hora extra. Baseado em um modelo matemático proposto na literatura para resolver problemas de dimensionamento de lotes, um modelo matemático para representar o PRL foi proposto. O PRL foi formulado como um problema de programação linear inteira mista (PLIM) e resolvido através do método exato branch and bound. Testes computacionais foram realizados com exemplares adaptados da literatura e abrangem os três parâmetros de interrupçã*** work approaches the capacitated Lot Resizing Problem (LRP) with multi-products and parallel machines. The lot resizing problem is a lot sizing problem variation which can be identified in productive systems with high rate of interruptions, as breaks, refuse, and others, impairing the planning production and making update needed as soon as interruptions happens. Three parameters for interruption were considered: corrective maintenance, insufficient man power and unavailability of raw material. Demand can be performed with back-orders and overtime requests. This work has the objective of minimize inventory holding costs, back-orders, setup and overtime costs. Based on a mathematical model proposed in the literature to solve the lot sizing problem, a mathematical model to represent the LRP was pro

关键词： Problema de dimensionamento de lotes Programação inteira mista Múltiplos produtos Hora extra Atraso Lot sizing problem mixed integer programming Multiple products Overtime Backorders Dissertação de mestrado

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Optimal design of vaccination policies: A case study for Newfoundland and Labrador

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OPERATIONS RESEARCH LETTERS 2024年 55卷

作者： Khoshbakhtian, Faraz Validi, Hamidreza Ventresca, Mario Aleman, Dionne Univ Toronto Dept Mech & Ind Engn Toronto ON Canada Texas Tech Univ Dept Ind Mfg & Syst Engn Lubbock TX 79409 USA Purdue Univ Sch Ind Engn W Lafayette IN USA Univ Toronto Inst Pandem Toronto ON Canada

This paper proposes pandemic mitigation vaccination policies for Newfoundland and Labrador (NL) based on two compact mixed integer programming (MIP) models of the distance-based critical node detection problem (DCNDP). Our main focus is on two variants of the DCNDP that seek to minimize the number of connections with lengths of at most one (1-DCNDP) and two (2-DCNDP). A polyhedral study for the 1-DCNDP is conducted, and new aggregated inequalities are provided for the 2-DCNDP. The computational experiments show that the 2-DCNDP with aggregated inequalities outperforms the one with disaggregated inequalities for graphs with a density of at least 0.5%. We also study the strategic vaccine allocation problem as a real-world application of the DCNDP and conduct a set of computational experiments on a simulated contact network of NL. Our computational results demonstrate that the DCNDP-based strategies can have a better performance in comparison with the real-world strategies implemented during COVID-19. (c) 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： The distance-based critical node detection problem Vaccination policies mixed integer programming

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On Integrating Theories of International Economics in the Strategic Planning of Global Supply Chains and Dynamic Supply Chain Reconfiguration with Capacity Expansion and Contraction

On Integrating Theories of International Economics in the St...

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作者： Lee, Chaehwa Texas A&M University

This dissertation discusses two independent topics. The first part of the dissertation relates three theories of international economics (comparative advantage, competitive advantage, and competitiveness), and formulates the thesis that incorporating them in the form of readily available individual competitiveness indicators in OR/MS models offers promise to enhance decision-support for the strategic planning of global supply chains in general, and for locating facilities in particular. The objectives of this research were to relate each of these theories and to describe their interrelationships; to describe measures provided by two well-known annual competitiveness reports; and to illustrate application of the theories as a means of supporting the thesis of the research, and justifying the research questions we pose for future research. While this research discusses topics relative to the broader background of global supply chain design, it illustrates applications associated with facility location, a component of the global supply chain design. In the last chapter of the first part of the dissertation, we provide a vision to foster future research that will enhance the profitability of international enterprises under NAFTA. The second part of the dissertation deals with the DSCR model with capacity expansion and contraction. The strategic dynamic supply chain reconfiguration (DSCR) problem is to prescribe the location and capacity of each facility, select links used for transportation, and plan material flows through the supply chain, including production, inventory, backorder, and outsourcing levels. The objective is to minimize total cost. The configuration must be dynamically redesigned over time to accommodate changing trends in demand and/or costs by opening facilities, expanding and/or contracting their capacities, and closing facilities. The problem involves a multi-period, multi-product, multi-echelon supply chain. Research objectives are alternative

关键词： international economics North American Free Trade Agreement global supply chains dynamic supply chain reconfiguration mixed integer programming Branch and Price Thesis

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Problemas de programação de produção em indústrias de embalagens de papelão ondulado.

Problemas de programação de produção em indústrias de e...

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作者： Ferreira, Marcelo Universidade Estadual Paulista

Nessa tese abordamos dois problemas reais identiﬁcados no processo produtivo de indústrias de embalagens de papelão ondulado, que denotaremos por Problema de Minimização de Trocas de Gramaturas e Rolos Corrugadores (PMTGRC) e Problema da Alocação de Bobinas no Corrugador (PABC). Ambos os problemas ocorrem no corrugador, máquina multiestágio que produz as chapas de papelão ondulado. O PMTGRC surge da necessidade de minimizar trocas de gramaturas e rolos corrugadores durante o processo de produção dos boletins, uma vez que cada boletim traz as gramaturas especíﬁcas das camadas da chapa, além do tipo de onda empregada no(s) miolos(s). O sequenciamento dos boletins impacta na quantidade de mudanças de gramaturas nos porta-bobinas e se haverátrocaderoloscorrugadoresparadoisboletinssubsequentes. Astrocasdegramaturas impactam em custos de transporte de bobinas e as trocas de rolos corrugadores impactam em perda de produtividade. Para o PMTGRC propomos quatro modelos inéditos de programação inteira capazes de integrar essas duas considerações. O PABC integra várias considerações relacionadas à alocação das bobinas no corrugador, como por exemplo, a minimização das sobras não aproveitáveis e das quantidades de consumos parciais, fatores que inﬂuenciam diretamente nos custos de produção. Um modelo linear inteiro misto inédito é proposto, determinando quais bobinas serão utilizadas em cada porta-bobinas. Além disso, propomos uma estratégia de sequenciamento das bobinas em cada porta-bobina, evitando paragens no corrugador. Uma série de testes computacionais utilizando instâncias geradas com base em dados reais foram realizados. Os resultados indicam que os modelos foram eﬁcientes em tratar os problemas *** this thesis we approached two real problems identiﬁed over the productive process of corrugated cardboard industries, which we will denote as the Minimization of Converting Weights and Corrugators Problem (MCWCP) and the Corrugators Coil Allocation Problem (CCAP). B

关键词： Programação inteira mista Modelagem matemática Indústria de embalagens de papelão Corrugador mixed integer programming Mathematical modeling Corrugated cardboard industries Corrugator Tese de doutorado

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Planning Ground Water Supply Systems for Urban Growth: A Multilevel Perspective

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IFAC Proceedings Volumes 1980年第3期13卷 295-305页

作者： J.W. Delleur S.A. Dendrou G.V. Loganathan School of Civil Engineering Purdue University West Lafayette Indiana 47907 USA Water Resources Engineers CDM Springfield Virginia 22151 USA

A methodology has been developed to include effectively water supply from groundwater in urban planning. The model LANDUSE for prediction of urban development and water demand is linked to the model WATSUP, an optimization oriented finite element based water supply model for prediction and optimization of future water supply configurations. The nonlinearity of the objective function due to nonlinear head losses has been circumvented by means of empirical relationships for head losses and design criteria for pump and pipe sizes. The requirement that some decision variables such as the number of wells, equalizing reservoirs, etc. be integer variables leads to a mixed integer programming formulation. A two level coordination scheme is used in locating an optimal number of facilities such that cost is minimized and a safe exploitation of aquifer in the future is guaranteed. The methodology is applied to an actual situation in West Lafayette, Indiana.

关键词： Finite elements large scale systems mixed integer programming optimization urban systems water resources

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CProS: A web-based application for chemical production scheduling

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COMPUTERS & CHEMICAL ENGINEERING 2022年 164卷

作者： Misra, Shamik Buttazoni, Lucas Ryan Avadiappan, Venkatachalam Lee, Ho Jae Yang, Martin Maravelias, Christos T. Indian Inst Technol Tirupati Dept Chem Engn Tirupati Andhra Pradesh India Univ Wisconsin Dept Chem & Biol Engn Madison WI USA Hongik Univ Dept Chem Engn Seoul South Korea Princeton Univ Dept Chem & Biol Engn Princeton NJ 08544 USA Princeton Univ Andlinger Ctr Energy & Environm Princeton NJ 08544 USA

While a large range of models and methods have been proposed in the literature for chemical production scheduling, very limited tools are available for researchers to test these methods. This communication describes a web-based application (CProS) that was recently developed to facilitate the generation and solution of chemical production scheduling instances. The application offers an interface through which a user can define an instance using the state-task network (STN) representation. Given an instance, the application then automatically generates a discrete-time STN-based mixed-integer linear programming (MIP) model. In addition, the user has the option to use three different solution methods: (1) tightening constraints;(2) a reformulation;and (3) a three-stage discrete-continuous algorithm. We showcase the functionality of the application through a case study. (c) 2022 Elsevier Ltd. All rights reserved.

关键词： Batch scheduling mixed integer programming Solution methods

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Exploiting Erraticism in Search

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OPERATIONS RESEARCH 2014年第1期62卷 114-122页

作者： Fischetti, Matteo Monaci, Michele Univ Padua Dept Informat Engn I-35131 Padua Italy

High sensitivity to initial conditions is generally viewed as a drawback of tree search methods because it leads to erratic behavior to be mitigated somehow. In this paper we investigate the opposite viewpoint and consider this behavior as an opportunity to exploit. Our working hypothesis is that erraticism is in fact just a consequence of the exponential nature of tree search that acts as a chaotic amplifier, so it is largely unavoidable. We propose a bet-and-run approach to actually turn erraticism to one's advantage. The idea is to make a number of short sample runs with randomized initial conditions, to bet on the "most promising" run selected according to certain simple criteria, and to bring it to completion. Computational results on a large testbed of mixed integer linear programs from the literature are presented, showing the potential of this approach even when embedded in a proof-of-concept implementation.

关键词： enumerative algorithms mixed integer programming restart

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Using hybrid algorithm to reduce non-working distance in intra- and inter-field logistics simultaneously for heterogeneous harvesters

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COMPUTERS AND ELECTRONICS IN AGRICULTURE 2019年 167卷 105065-000页

作者： He, Pengfei Li, Jing Qin, Hailong He, Yanping Cao, Guangqiao Nanjing Agr Univ Fac Engn Nanjing 210031 Jiangsu Peoples R China Sino German Plant Prod & Agrotechnol Pk Xiangshui 224600 Peoples R China Jiangsu Prov Agr Reclamat & Dev Corp Huanghai Branch Xiangshui 224600 Peoples R China Minist Agr Nanjing Res Inst Agr Mechanizat Nanjing 210014 Jiangsu Peoples R China

Reducing the non-working distance for agricultural vehicles is beneficial for reducing the total operational costs for farmers. In this study, we optimize the non-working distance in intra- and inter-fields simultaneously for harvesters while harvesting rice. A mixed integer programming is presented for optimizing the rice harvesting problem, where a similar working time for all harvesters are considered based on a real case. Besides, in this model, two kinds of fields, namely moist and non-moist fields are considered, where the first can only be harvested by crawler harvesters while the second can be harvested by any type of harvester. This model aims to find an optimal schedule for the harvesters. A hybrid algorithm using both adaptive large neighborhood search and tabu search techniques is implemented to optimize the problem. A case study is considered to verify the performance of the hybrid algorithm. The results indicate that the hybrid algorithm is an effective method for solving the rice harvesting problem because the total non-working distance could be improved significantly by 15.3%. The proportion of moist fields is analyzed because it influences the schedule significantly. When compared to the traditional method for optimizing the non-working distance for harvesters, the total non-working distance in this method could be reduced by 6.2%. This paper provides farmers with a general framework for reducing the non-working distance in intra- and inter-field logistics, which results in a more efficient performance of the harvesters in the fields.

关键词： Rice mixed integer programming Adaptive large neighborhood search Moist

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Modeling Geographical Anycasting Routing in Vehicular Networks

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KSII TRANSACTIONS ON INTERNET AND INFORMATION SYSTEMS 2020年第4期14卷 1624-1647页

作者： Amirshahi, Alireza Romoozi, Morteza Raayatpanah, Mohammad Ali Asghari, Seyyed Amir Islamic Azad Univ Dept Comp Engn Qom Branch Qom Iran Islamic Azad Univ Dept Comp Engn Kashan Branch Kashan Iran Kharazmi Univ Fac Math Sci & Comp Tehran Iran Kharazmi Univ Tehran Comp & Elect Engn Dept Tehran Iran

Vehicular network is one of the most important subjects for researchers in recent years. Anycast routing protocols have many applications in vehicular ad hoc networks. The aim of an anycast protocol is sending packets to at least one of the receivers among candidate receivers. Studies done on anycast protocols over vehicular networks, however, have capability of implementation on some applications;they are partial, and application specific. No need to say that the lack of a comprehensive study, having a strong analytical background, is felt. Mathematical modeling in vehicular networks is difficult because the topology of these networks is dynamic. In this paper, it has been demonstrated that vehicular networks can be modeled based on time-expanded networks. The focus of this article is on geographical anycast. Three different scenarios were proposed including sending geographic anycast packet to exactly-one-destination, to at-least-one-destination, and to K-anycast destination, which can cover important applications of geographical anycast routing protocols. As the proposed model is of MILP type, a decentralized heuristic algorithm was presented. The evaluation process of this study includes the production of numerical results by Branch and Bound algorithm in general algebraic modeling system (GAMS) software and simulation of the proposed protocol in OMNET++ simulator. The comprehension of the result of proposed protocol and model shows that the applicability of this proposed protocol and its reactive conformity with the presented models based on presented metrics.

关键词： Anycast routing Vehicular networks Time-expanded networks Branch and Bound algorithm mixed integer programming

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