A Two-Warehouse Model for Deteriorating Items with Holding Cost under Particle Swarm Optimization

A deterministic inventory model has been developed for deteriorating items and Particle Swarm Optimization (PSO) having a ramp type demands with the effects of inflation with two-warehouse facilities. The owned warehouse (OW) has a fixed capacity of W units; the rented warehouse (RW) has unlimited capacity. Here, we assumed that the inventory holding cost in RW is higher than those in OW. Shortages in inventory are allowed and partially backlogged and Particle Swarm Optimization (PSO) it is assumed that the inventory deteriorates over time at a variable deterioration rate. The effect of inflation has also been considered for various costs associated with the inventory system and Particle Swarm Optimization (PSO). Numerical example is also used to study the behaviour of the model. Cost minimization technique is used to get the expressions for total cost and other parameters

Efficiency of the rail sections in Brazilian railway system, using TOPSIS and a genetic algorithm to analyse optimized scenarios

A railway system plays a significant role in countries with large territorial dimensions. The Brazilian rail cargo system (BRCS), however, is focused on solid bulk for export. This paper investigates the extreme performances of BRCS through a new hybrid model that combines TOPSIS with a genetic algorithm for estimating the weights in optimized scenarios. In a second stage, the significance of selected variables was assessed. The transport of any type of cargo, a centralized control of the operation, and sharing the railway track pushing competition, and the diversification of services are significant for high performance. Public strategies are discussed.Indisponível

A competitive mechanism based multi-objective particle swarm optimizer with fast convergence

In the past two decades, multi-objective optimization has attracted increasing interests in the evolutionary computation community, and a variety of multi-objective optimization algorithms have been proposed on the basis of different population based meta-heuristics, where the family of multi-objective particle swarm optimization is among the most representative ones. While the performance of most existing multi-objective particle swarm optimization algorithms largely depends on the global or personal best particles stored in an external archive, in this paper, we propose a competitive mechanism based multi-objective particle swarm optimizer, where the particles are updated on the basis of the pairwise competitions performed in the current swarm at each generation. The performance of the proposed competitive multi-objective particle swarm optimizer is verified by benchmark comparisons with several state-of-the-art multiobjective optimizers, including three multi-objective particle swarm optimization algorithms and three multi-objective evolutionary algorithms. Experimental results demonstrate the promising performance of the proposed algorithm in terms of both optimization quality and convergence speed

Analytic hierarchy process and technique for order preference by similarity to ideal solution: a bibliometric analysis from past, present and future of AHP and TOPSIS

Previous review papers on analytic hierarchy process (AHP) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) mainly focused on the application areas and paid scant attention to the framework development of AHP, TOPSIS and their hybrid methods. The purpose of this paper is to review the literature on analytic hierarchy process (AHP), type of scale used in AHP, modified AHP, rank reversal problem of AHP, validation of AHP, application of AHP, TOPSIS, normalization methods for TOPSIS, distance functions for TOPSIS, fuzzy hierarchical TOPSIS, rank reversal problem of TOPSIS and various applications of TOPSIS to prepare a readymade reference for academician, research scholar and industry people. In this regard, research works are gathered from 1980 to 2013 (searched via ScienceDirect, IEEE etc) and out of which 61 research papers are critically assayed to depict the development of AHP, TOPSIS and their hybrid methods. Meaningful information and critical remarks are summarized in various tabular formats and charts to give readers easy information

Analytic hierarchy process and technique for order preference by similarity to ideal solution: a bibliometric analysis from past, present and future of AHP and TOPSIS

Previous review papers on analytic hierarchy process (AHP) and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) mainly focused on the application areas and paid scant attention to the framework development of AHP, TOPSIS and their hybrid methods. The purpose of this paper is to review the literature on analytic hierarchy process (AHP), type of scale used in AHP, modified AHP, rank reversal problem of AHP, validation of AHP, application of AHP, TOPSIS, normalization methods for TOPSIS, distance functions for TOPSIS, fuzzy hierarchical TOPSIS, rank reversal problem of TOPSIS and various applications of TOPSIS to prepare a readymade reference for academician, research scholar and industry people. In this regard, research works are gathered from 1980 to 2013 (searched via ScienceDirect, IEEE etc) and out of which 61 research papers are critically assayed to depict the development of AHP, TOPSIS and their hybrid methods. Meaningful information and critical remarks are summarized in various tabular formats and charts to give readers easy information

A Hybrid Meta-Heuristic Method to Optimize Bi-Objective Single Period Newsboy Problem with Fuzzy Cost and Incremental Discount

In this paper the real-world occurrence of the multiple-product multiple-constraint single period newsboy problem with two objectives, in which there is incremental discounts on the purchasing prices, is investigated. The constraints are the warehouse capacity and the batch forms of the order placements. The first objective of this problem is to find the order quantities such that the expected profit is maximized and the second objective is maximizing the service rate. It is assumed that holding and shortage costs, modeled by a quadratic function, occur at the end of the period, and that the decision variables are integer. A formulation to the problem is presented and shown to be an integer nonlinear programming model. Finally, an efficient hybrid algorithm of harmony search, goal programming, and fuzzy simulation is provided to solve the model. The results are illustrated by a numerical example

Efficiency in rail systems through three different approaches and contributions to push the Brazilian rail system toward high performance

Tese (Doutorado em Administração) - Universidade Federal do Rio de Janeiro, Rio de Janeiro, 2019Inclui bibliografiaThis research investigates the efficiency of the Brazilian rail cargo system (SFBC, acronym in Portuguese). The importance of the performance of a rail system to the logistics of goods in countries with large territorial dimensions is recognized. However, its role is secondary in Brazil compared to road transport, representing high economic and environmental costs. SFBC is dedicated to the export of mineral and agricultural bulk where it has a significant capacity for insertion. Meanwhile, the SFBC has an insignificant participation in the internal distribution of goods, which is mostly done in highways, including on longer routes. Consequently, the transport sector in Brazil emits twice as much CO2 from buming fuels than the world average. SFBC presents characteristics of a medium performance scenario. The performance of the operators is heterogeneous, benchmarking is an outlier, the average efficiency is low, and the average idleness of the sections is high. To discuss the conditions to achieve a high performance scenario is the main contribution of this thesis. Three researches were done to address this issue. The first one is dedicated to estimate the efficiency of the railway concessionaires in Brazil between 2010-2014 by using Data Envelopment Analysis. In a second stage, the significance of selected variables was assessed through Bootstrap Truncated Regression, including the type of the use of the railway track (shared or monopoly), a gap in the literature. The operators were grouped according to the efficiency scores and the type of returns to scale, and measures to increase the efficiency of the clusters were discussed. The second research has the purpose to explain the heterogeneity found in the average efficiency of the different railway systems in the world, the object of researches done between 2000-2016, through a meta-analysis carried out for the first time onj railways. For greater robustness, Leave-One-Out-Cross-Validation and VVeighted Regression were applied. Public policies induding diversification of services and models for assessing efficiency by regulatory agencies were discussed. The third research is devoted to the efficiency of the SFBC raílway sections and identifies the significant conditions for high and low performance scenarios by combining the Technique for Order of Preference by Similarity to Ideal Solution and a differential evolution algorithm for estimating the weights of variables in optimized scenarios, another gap in the literature. In a second stage, the significance of the variables selected was evaluated. The research shows that the public manager should push the rail companies toward the transportation of any type of cargo, the diversification of services, the centralized control of the operation, and the sharing of the railway track. The competition and diversifìcation are significant for high performance.A pesquisa investiga a eficiência do Sistema Ferroviário Brasileiro de Cargas (SFBC). É reconhecida a importância do desempenho de um sistema ferroviário para a logística de mercadorias em países de grandes dimensões territoriais. Todavia, seu papel é secundário no Brasil frente ao transporte rodoviário, representando custos econômicos e ambientais excedentes. O SFBC se mantém dedicado à exportação de granéis sólidos minerais e agrícolas onde apresenta significativa capacidade de inserção, enquanto é inexpressiva sua participação na distribuição interna de bens, majoritariamente realizada pelo setor rodoviário, inclusive em rotas mais longas. Assim, o setor de transporte no Brasil emite o dobro de CO2 pela queima de combustíveis do que a média mundial. O SFBC apresenta características de um cenário de média performance. O desempenho dos operadores é heterogêneo, o benchmarking é um outlier, a eficiência média é baixa e a ociosidade média das seções é alta. Discutir as condições para alcançar um cenário de alta performance é a principal contribuição da tese. Para atingir esse objetivo, foram realizadas três pesquisas. A primeira se dedica à eficiência dos concessionários ferroviários no Brasil no período 2010-2014, com o uso de Data Envelopment Analysis. Num segundo estágio, através de Bootstrap Truncated Regression, foi avaliada a significância de variáveis selecionadas, incluindo o tipo de uso da via, gap da literatura. Os operadores foram agrupados segundo os resultados de eficiência e o tipo de retornos de escala das operações e medidas para o aumento da eficiência dos clusters foram discutidas. A segunda pesquisa tem por objetivo explicar a heterogeneidade encontrada na eficiência média de diversos sistemas ferroviários no mundo, objeto de pesquisas realizadas entre 2000-2016, através de uma metanálise conduzida pela primeira vez em ferrovias. Para maior robutez, Leave-One-Out-Cross-Validation e Weighted Regression foram utilizadas. Políticas públicas incluindo diversificação e modelos de avaliação de eficiência por órgãos reguladores foram comentadas. A terceira pesquisa se dedica à eficiência das seções ferroviárias e identifica as condições significativas para cenários de alta e baixa performance através da combinação de Technique for Order of Preference by Similarity to Ideal Solution e de um algoritmo de evolução diferencial para estimar os pesos de variáveis em cenários otimizados, gap da literatura. Num segundo estágio, a significância de variáveis selecionadas foi avaliada. A pesquisa mostra que o gestor público deve empurrar as empresas para o transporte de todo o tipo de carga, a diversificação de serviços, o controle centralizado da operação e o compartilhamento da via. A competição e a diversificação são significativas para a alta performance