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Publications

Publications by LIAAD

2018

Metaheuristic Algorithms in Maritime Operations Optimization

Authors
Homayouni, SM; Fontes, DBMM;

Publication
Metaheuristic Algorithms in Maritime Operations Optimization

Abstract
Metaheuristic Algorithms in Maritime Operations Optimization focuses on the seaside and port side problems regarding the maritime transportation. The book reviews and introduces the most important problems regarding the shipping network design, long-term and short-term scheduling and planning problems in both bulk and container shipping as well as liquid maritime transportation. Application of meta heuristic algorithm is important for these problems, as most of them are hard and time-consuming to be solved optimally.

2018

A nonconvex quadratic optimization approach to the maximum edge weight clique problem

Authors
Hosseinian, S; Fontes, DBMM; Butenko, S;

Publication
JOURNAL OF GLOBAL OPTIMIZATION

Abstract
The maximum edge weight clique (MEWC) problem, defined on a simple edge-weighted graph, is to find a subset of vertices inducing a complete subgraph with the maximum total sum of edge weights. We propose a quadratic optimization formulation for the MEWC problem and study characteristics of this formulation in terms of local and global optimality. We establish the correspondence between local maxima of the proposed formulation and maximal cliques of the underlying graph, implying that the characteristic vector of a MEWC in the graph is a global optimizer of the continuous problem. In addition, we present an exact algorithm to solve the MEWC problem. The algorithm is a combinatorial branch-and-bound procedure that takes advantage of a new upper bound as well as an efficient construction heuristic based on the proposed quadratic formulation. Results of computational experiments on some benchmark instances are also presented.

2018

Modeling lean manufacturing success

Authors
Ghobakhloo, M; Fathi, M; Fontes, DBMM; Ching, NT;

Publication
JOURNAL OF MODELLING IN MANAGEMENT

Abstract
Purpose The purpose of this study is to contribute to the existing knowledge about the process of achieving Lean Manufacturing (LM) success. Design/methodology/approach This study uses interpretive structural modeling and captures the opinions of a group of LM experts from a world-class Japanese automobile manufacturer, to map the interrelationships among potential determinants of LM success. This study further uses the data from a survey of 122 leading automobile part manufacturers by performing structural equation modeling to empirically test the research model proposed. Findings Management support and commitment, financial resources availability, information technology competence for LM, human resources management, production process simplicity, supportive culture and supply chain-wide integration are the key determinants that directly or indirectly determine the level of achievement of LM success. Research limitations/implications The determinants of LM success as experienced by Asian automobile manufacturers might be different from determinants of LM success as experienced by Western automobile manufacturers. An interesting direction for future research would be to capture the experts' inputs from Western automobile manufacturers to complement the findings of this study. Practical implications The practical contribution of this study lays in the development of linkages among various LM success determinants. Utility of the proposed interpretive structural modeling and structural equation modeling methodologies imposing order, direction and significance of the relationships among elements of LM success assumes considerable value to the decision-makers and LM practitioners. Originality/value Building on opinions of a group of LM experts and a case study of leading auto part manufacturers, the present study strives to model the success of LM, a topic that has received little attention to date.

2018

Optimal Reorganization of a Formation of Nonholonomic Agents Using Shortest Paths

Authors
Caldeira, ACD; Paiva, LT; Fontes, DBMM; Fontes, FACC;

Publication
2018 13TH APCA INTERNATIONAL CONFERENCE ON CONTROL AND SOFT COMPUTING (CONTROLO)

Abstract
In this work we address the problem of switching the shape of a formation of undistinguishable nonholonomic mobile robots. Each agent moves from the current to its target oriented position using the shortest path. We combine results from previous work on optimal formation switching when the agents are holonomic with results on the structure of the shortest path for nonholonomic agents.

2018

Cournot duopolies with investment in R&D: Regions of nash investment equilibria

Authors
Oliveira, BMPM; Becker Paulo, J; Pinto, AA;

Publication
Springer Proceedings in Mathematics and Statistics

Abstract
We study a model of a Cournot duopoly where firms invest in R&D to reduce their production costs. Depending on the parameters, we may find regions with one, two or three Nash equilibria of the investment. Here, we study the effect of the parameters in these regions, in particular, we study the effect of the possible market saturation, the maximum relative cost reduction and the product differentiation, giving special attention to regions with multiple Nash equilibria. We observed that, in general, the competitive region, where both firms invest, is reduced as we increase the possible market saturation and the differentiation of the products and is enlarged when we increase the maximum relative cost reduction. © 2018, Springer International Publishing AG, part of Springer Nature.

2018

Operational Research

Authors
Vaz, AIF; Almeida, JP; Oliveira, JF; Pinto, AA;

Publication
Springer Proceedings in Mathematics & Statistics

Abstract

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