775 research outputs found

    Optimization of Location-Routing for the Waste Household Appliances Recycling Logistics under the Uncertain Condition

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    Waste household appliances and electronic products usually contain harmful substances which need scientific and reasonable collection, classification, processing, recovery and disposal to achieve sustainable and effective recycling and utilization. In recent years, due to the poor management of waste household appliances recycling logistics system, safety accidents occur frequently, which seriously harm the health and life safety of the society. This paper studies the risk management of recycling waste household appliances under uncertain conditions and establishes a risk measurement model under fuzzy population density. Considering the multi-stage and classification diversity of waste household appliances recycling logistics, the multi-objective location routing model and location - routing model are established respectively. Based on the model complexity analysis, the solution method of multi-objective model is designed. Finally, the validity of the model and algorithm is verified by examples and tests

    Fuzzy Robust Optimization in Closed-Loop Supply Chain Network Model for Hazardous Products (Lead-Acid Battery)

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    Purpose: This paper models a closed-loop supply chain network problem for hazardous products in the face of demand uncertainty and variable costs. The designed model includes a set of suppliers, production centers, distribution, recycling, disposal, collection and end customers in which strategic and tactical decisions are made simultaneously. Among the decisions made in this paper is the location of production, distribution and collection centers and determining the optimal amount of product flow between the levels of the supply chain network. Methodology: In this paper, the Epsilon constraint method is used to solve a multi-objective model in GMAS software. This article also uses uniform data to solve the problem. Findings: The results of solving the model with fuzzy robust optimization method show that with increasing the uncertainty rate and also reducing the transfer time of hazardous products, the total network costs as well as the amount of greenhouse gas emissions have increased. Also, the study of Pareto front to optimize the total design costs and the amount of greenhouse gas emissions shows that by reducing the amount of greenhouse gas emissions in the network, the costs related to location and routing increase. Originality/Value: In this paper a fuzzy robust optimization is used in closed-loop supply chain network model for hazardous products (Lead-Acid Battery)

    Combining heuristics with simulation and fuzzy logic to solve a flexible-size location routing problem under uncertainty

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    The location routing problem integrates both a facility location and a vehicle routing problem. Each of these problems are NP-hard in nature, which justifies the use of heuristic-based algorithms when dealing with large-scale instances that need to be solved in reasonable computing times. This paper discusses a realistic variant of the problem that considers facilities of different sizes and two types of uncertainty conditions. In particular, we assume that some customers’ demands are stochastic, while others follow a fuzzy pattern. An iterated local search metaheuristic is integrated with simulation and fuzzy logic to solve the aforementioned problem, and a series of computational experiments are run to illustrate the potential of the proposed algorithm.This work has been partially supported by the Spanish Ministry of Science (PID2019-111100RB-C21/AEI/10.13039/501100011033). In addition, it has received the support of the Doctoral School at the Universitat Oberta de Catalunya (Spain) and the Universidad de La Sabana (INGPhD-12-2020).Peer ReviewedPostprint (published version

    El problema de localización y ruteo con múltiples objetivos: una revisión de literatura

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    Contexto: El problema de localización y ruteo constituye una de las principales temáticas en el área de logística e investigación de operaciones con un enfoque hacia la minimización de los costos totales del sistema. Sin embargo, en la gestión de la cadena de suministro, que actualmente presenta una tendencia hacia la sostenibilidad, la mayoría de las decisiones involucra la optimización simultánea de diversos objetivos, incluyendo perspectivas económicas, sociales y ambientales, de lo cual surge el problema de localización y ruteo con múltiples objetivos. Método: Se realiza una revisión sistemática de la literatura sobre el problema de localización y ruteo con múltiples objetivos, consultando las bases de datos Scopus y Web of Science. De acuerdo con unos criterios de selección específicos, se identifican 99 artículos científicos asociados a la temática durante el periodo comprendido entre 1989 y 2022, los cuales se clasifican según el tipo de aplicación. Resultados: Se describen las características más importantes para cada una de las aplicaciones del problema de localización y ruteo con múltiples objetivos en la literatura y se realiza una revisión de las investigaciones según sus objetivos de estudio y métodos de solución, para finalmente identificar las oportunidades de investigación principales. Conclusiones: En primer lugar, la mayoría de los estudios sobre el problema de localización y ruteo multiobjetivo han estudiado la gestión de residuos, la distribución de elementos de socorro, los productos perecederos, el problema de localización y ruteo verde, la cadena de frío y la distribución de bebidas. El objetivo de optimización de mayor implementación es la minimización de costos, combinado con otros objetivos: minimización de riesgos, impactos ambientales, minimización de tiempo, maximización de la satisfacción del cliente, balance de carga de trabajo y confiabilidad rutas. Por otra parte, se aplican métodos exactos y aproximados multiobjetivo para dar solución al problema, siendo los algoritmos evolutivos los más usados para modelos de mayor complejidad. Finalmente, las investigaciones actuales están orientadas al desarrollo de modelos bajo condiciones de incertidumbre y estocásticos, múltiples periodos, ventanas de tiempo, múltiples escalones y flota heterogénea.Contexto: El problema de localización y ruteo constituye una de las principales temáticas en el área de logística e investigación de operaciones con un enfoque hacia la minimización de los costos totales del sistema. Sin embargo, en la gestión de la cadena de suministro, que actualmente presenta una tendencia hacia la sostenibilidad, la mayoría de las decisiones involucra la optimización simultánea de diversos objetivos, incluyendo perspectivas económicas, sociales y ambientales, de lo cual surge el problema de localización y ruteo con múltiples objetivos. Método: Se realiza una revisión sistemática de la literatura sobre el problema de localización y ruteo con múltiples objetivos, consultando las bases de datos Scopus y Web of Science. De acuerdo con unos criterios de selección específicos, se identifican 99 artículos científicos asociados a la temática durante el periodo comprendido entre 1989 y 2022, los cuales se clasifican según el tipo de aplicación. Resultados: Se describen las características más importantes para cada una de las aplicaciones del problema de localización y ruteo con múltiples objetivos en la literatura y se realiza una revisión de las investigaciones según sus objetivos de estudio y métodos de solución, para finalmente identificar las oportunidades de investigación principales. Conclusiones: En primer lugar, la mayoría de los estudios sobre el problema de localización y ruteo multiobjetivo han estudiado la gestión de residuos, la distribución de elementos de socorro, los productos perecederos, el problema de localización y ruteo verde, la cadena de frío y la distribución de bebidas. El objetivo de optimización de mayor implementación es la minimización de costos, combinado con otros objetivos: minimización de riesgos, impactos ambientales, minimización de tiempo, maximización de la satisfacción del cliente, balance de carga de trabajo y confiabilidad rutas. Por otra parte, se aplican métodos exactos y aproximados multiobjetivo para dar solución al problema, siendo los algoritmos evolutivos los más usados para modelos de mayor complejidad. Finalmente, las investigaciones actuales están orientadas al desarrollo de modelos bajo condiciones de incertidumbre y estocásticos, múltiples periodos, ventanas de tiempo, múltiples escalones y flota heterogénea

    Reverse Logistics Network Design with a 3-Phase Interactive Intuitionistic Fuzzy Goal Programming Approach: A Case Study of Covid-19 in Pathum Thani, Thailand

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    During outbreaks, a vast quantity of Infected Medical Waste (IMW) can be substantially generated in a short period, which poses a massive risk to medical personnel and surrounding communities. This study proposes an Intuitionistic Fuzzy Multi-Objective Multi-Period Mixed-Integer Linear Programming (IFMOMILP) model for effective IMW management in outbreaks under uncertainty, considering financial and risk factors subject to a priority from Decision Makers (DMs). The primary emphasis is on determining the optimal locations and capacity levels for temporary facilities, including temporary storage and treatment centers, as well as the optimal transportation routes. A 3-phase interactive Intuitionistic Fuzzy Goal Programming (i-IFGP) approach is developed to solve this IFMOMILP model. First, the Jiménez approach is applied to handle the uncertainties. Then, the problem is solved by Intuitionistic Fuzzy Goal Programming (IFGP). An actual case study of the COVID-19 outbreak in Pathum Thani province in Thailand was carried out to demonstrate the effectiveness of the proposed approach. The proposed approach yields solutions with varying feasibility degrees and scaling factors, providing alternatives for DMs. Then, the score function is utilized to imply DMs’ satisfaction with the outcomes, which is a concrete measure since it can reflect the intention of the DMs

    Facility Location Problems: Models, Techniques, and Applications in Waste Management

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    This paper presents a brief description of some existing models of facility location problems (FLPs) in solid waste management. The study provides salient information on commonly used distance functions in location models along with their corresponding mathematical formulation. Some of the optimization techniques that have been applied to location problems are also presented along with an appropriate pseudocode algorithm for their implementation. Concerning the models and solution techniques, the survey concludes by summarizing some recent studies on the applications of FLPs to waste collection and disposal. It is expected that this paper will contribute in no small measure to an integrated solid waste management system with specific emphasis on issues associated with waste collection, thereby boosting the drive for e�ective and e�cient waste collection systems. The content will also provide early career researchers with some necessary starting information required to formulate and solve problems relating to FLP

    Formulation and solution technique for agricultural waste collection and transport network design

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    Agricultural waste management in developing countries has become a challenging issue for rural planners due to the lack of an efficient planning tool. In the countries, farmers burnt agricultural waste at fields after each harvesting season to solve the issue. As a result, it has caused air and water pollution in the rural areas of the countries. In this paper, we present a mixed-integer nonlinear programming model for agricultural waste collection and transport network design that aims to stop burning waste and use the waste to produce bio-organic fertilizer. The model supports rural planners to optimally locate waste storages, and to determine the optimal set of routes for a fleet of vehicles to collect and transport the waste from the storages to the bio-organic fertilizer production facility. In the novel location-assignment-routing problem, the overall objective is to minimize total cost of locating storages, collecting waste from fields and planning vehicle routes. A solution technique is developed to linearise the mixed-integer nonlinear programming model into a model in linear form. In addition, a parallel water flow algorithm is developed to solve efficiently the large-sized instances. The efficiency of the proposed model and algorithm is validated and evaluated on the real case study in Trieu Phong district, Quang Tri province, Vietnam, as well as a set of randomly generated large-sized instances. The results show that our solution approach outperforms the general optimisation solver and tabu search algorithm. Our algorithm can find the optimal or near-optimal solutions for the large-sized instances within a reasonable time

    Intermodal transportation of hazardous materials with supplier selection : application in Turkey

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    Ankara : The Department of Industrial Engineering and the Graduate School of Engineering and Science of Bilkent University, 2011.Thesis (Master's) -- Bilkent University, 2011.Includes bibliographical references leaves 81-84.Fuel transportation constitutes a significant portion of hazardous materials transportation for decades. Fuel companies generally prefer highway transportation whereas railway transportation is also a potential alternative due to its advantages both from cost- and risk perspectives. The aim of this thesis is to investigate the potential benefits of using railways in conjunction to highways for fuel transportation in Turkey. In this thesis, we first investigate a quantitative risk model that could be used to assess the risk of railway transportation. Then, a mathematical model is developed which aims to answer the following three questions: What should be the routes of fuel products transported from suppliers to demand points and which transportation mode(s) should be used on these routes?, Where to open transfer units?, and Which suppliers should satisfy which demand points with what capacity?. The model has two possibly conflicting objectives of minimizing the total transportation risk and minimizing the total transportation cost. The proposed models are tested over Turkish network for which all required realistic data are collected.Elaldı, PelinM.S
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