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Author Pereira, J.
Title Procedures for the bin packing problem with precedence constraints Type
Year (up) 2016 Publication European Journal Of Operational Research Abbreviated Journal Eur. J. Oper. Res.
Volume 250 Issue 3 Pages 794-806
Keywords Bin packing; Precedence constraints; Lower bounds; Dynamic programming; Branch-and-bound
Abstract The bin packing problem with precedence constraints (BPP-P) is a recently proposed variation of the classical bin packing problem (BPP), which corresponds to a basic model featuring many underlying characteristics of several scheduling and assembly line balancing problems. The formulation builds upon the BPP by incorporating precedence constraints among items, which force successor items to be packed into later bins than their predecessors. In this paper we propose a dynamic programming based heuristic, and a modified exact enumeration procedure to solve the problem. These methods make use of several new lower bounds and dominance rules tailored for the problem in hand. The results of a computational experiment show the effectiveness of the proposed methods, which are able to close all of the previous open instances from the benchmark instance set within very reduced running times. (C) 2015 Elsevier B.V. and Association of European Operational Research Societies (EURO) within the International Federation of Operational Research Societies (IFORS). All rights reserved.
Address [Pereira, Jordi] Univ Adolfo Ibanez, Fac Sci & Engn, Ave Padre Hurtado 750,Off C216, Vina Del Mar, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0377-2217 ISBN Medium
Area Expedition Conference
Notes WOS:000369192500011 Approved
Call Number UAI @ eduardo.moreno @ Serial 581
Permanent link to this record
 
 
Author Pereira, J.
Title The robust (minmax regret) single machine scheduling with interval processing times and total weighted completion time objective Type
Year (up) 2016 Publication Computers & Operations Research Abbreviated Journal Comput. Oper. Res.
Volume 66 Issue Pages 141-152
Keywords Scheduling; Single machine; Uncertainty; Robust optimization; Branch-and-bound
Abstract Single machine scheduling is a classical optimization problem that depicts multiple real life systems in which a single resource (the machine) represents the whole system or the bottleneck operation of the system. In this paper we consider the problem under a weighted completion time performance metric in which the processing time of the tasks to perform (the jobs) are uncertain, but can only take values from closed intervals. The objective is then to find a solution that minimizes the maximum absolute regret for any possible realization of the processing times. We present an exact branch-and-bound method to solve the problem, and conduct a computational experiment to ascertain the possibilities and limitations of the proposed method. The results show that the algorithm is able to optimally solve instances of moderate size (25-40 jobs depending on the characteristics of the instance). (c) 2015 Elsevier Ltd. All rights reserved.
Address [Pereira, Jordi] Univ Adolfo Ibanez, Fac Sci & Engn, Vina Del Mar, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-0548 ISBN Medium
Area Expedition Conference
Notes WOS:000366779900013 Approved
Call Number UAI @ eduardo.moreno @ Serial 558
Permanent link to this record
 
 
Author Pereira, J.; Vila, M.
Title A new model for supply chain network design with integrated assembly line balancing decisions Type
Year (up) 2016 Publication International Journal Of Production Research Abbreviated Journal Int. J. Prod. Res.
Volume 54 Issue 9 Pages 2653-2669
Keywords decomposition; mixed integer linear programming; supply chain design; line balancing; SALBP-1
Abstract Supply chain network design aims at the integration of the different actors of a supply chain within a single framework in order to optimise the total profit of the system. In this paper, we consider the integration of line balancing issues within the tactical decisions of the supply chain, and we offer a novel model and a solution approach for the problem. The new approach decomposes the problem into multiple line balancing problems and a mixed integer linear model, which is easier to solve than the previously available non-linear mixed integer formulation. The results show that the new method is able to solve previously studied models within a fraction of the reported running times, and also allows us to solve larger instances than those reported in earlier works. Finally, we also provide some analysis on the influence of the cost structure, the demand and the structure of the assembly process on the final configuration of the assemblies and the distribution network.
Address [Pereira, Jordi] Univ Adolfo Ibanez, Fac Sci & Engn, Vina Del Mar, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Taylor & Francis Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-7543 ISBN Medium
Area Expedition Conference
Notes WOS:000373632300009 Approved
Call Number UAI @ eduardo.moreno @ Serial 608
Permanent link to this record
 
 
Author Alvarez-Miranda, E.; Pereira, J.
Title Designing and constructing networks under uncertainty in the construction stage: Definition and exact algorithmic approach Type
Year (up) 2017 Publication Computers & Operations Research Abbreviated Journal Comput. Oper. Res.
Volume 81 Issue Pages 178-191
Keywords Network design; Network construction; Two-stage robust optimization; Exact algorithms
Abstract The present work proposes a novel Network Optimization problem whose core is to combine both network design and network construction scheduling under uncertainty into a single two-stage robust optimization model. The first-stage decisions correspond to those of a classical network design problem, while the second-stage decisions correspond to those of a network construction scheduling problem (NCS) under uncertainty. The resulting problem, which we will refer to as the Two-Stage Robust Network Design and Construction Problem (2SRNDC), aims at providing a modeling framework in which the design decision not only depends on the design costs (e.g., distances) but also on the corresponding construction plan (e.g., time to provide service to costumers). We provide motivations, mixed integer programming formulations, and an exact algorithm for the 2SRNDC. Experimental results on a large set of instances show the effectiveness of the model in providing robust solutions, and the capability of the proposed algorithm to provide good solutions in reasonable running times. (C) 2017 Elsevier Ltd. All rights reserved.
Address [Alvarez-Miranda, Eduardo] Univ Talca, Dept Ind Engn, Curico, Chile, Email: ealvarez@utalca.cl
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-0548 ISBN Medium
Area Expedition Conference
Notes WOS:000394079400015 Approved
Call Number UAI @ eduardo.moreno @ Serial 706
Permanent link to this record
 
 
Author Pereira, J.; Vasquez, O.C.
Title The single machine weighted mean squared deviation problem Type
Year (up) 2017 Publication European Journal Of Operational Research Abbreviated Journal Eur. J. Oper. Res.
Volume 261 Issue 2 Pages 515-529
Keywords Scheduling; Single machine; JIT; Branch-and-cut; Dominance properties
Abstract This paper studies a single machine problem related to the just-In-Time (JIT) production objective in which the goal is to minimize the sum of weighted mean squared deviation of the completion times with respect to a common due date. In order to solve the problem, several structural and dominance properties of the optimal solution are investigated. These properties are then integrated within a branch and-cut approach to solve a time-indexed formulation of the problem. The results of a computational experiment with the proposed algorithm show that the method is able to optimally solve instances with up to 300 jobs within reduced running times, improving other integer programming approaches. (C) 2017 Elsevier B.V. All rights reserved.
Address [Pereira, Jordi] Univ Adolfo Ibanez, Dept Engn & Sci, Av Padre Hurtado 750,Off C216, Vina Del Mar, Chile, Email: jorge.pereira@uai.cl;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0377-2217 ISBN Medium
Area Expedition Conference
Notes WOS:000401206300009 Approved
Call Number UAI @ eduardo.moreno @ Serial 730
Permanent link to this record
 
 
Author Pereira, J.
Title The robust (minmax regret) assembly line worker assignment and balancing problem Type
Year (up) 2018 Publication Computers & Operations Research Abbreviated Journal Comput. Oper. Res.
Volume 93 Issue Pages 27-40
Keywords Production; Line balancing; Robust optimization; Minmax regret
Abstract Line balancing aims to assign the assembly tasks to the stations that compose the assembly line. A recent body of literature has been devoted to heterogeneity in the assembly process introduced by different workers. In such an environment, task times depend on the worker performing the operation and the problem aims at assigning tasks and workers to stations in order to maximize the throughput of the line. In this work, we consider an interval data version of the assembly line worker assignment and balancing problem (ALWABP) in which it is assumed that lower and upper bounds for the task times are known, and the objective is to find an assignment of tasks and workers to the workstations such that the absolute maximum regret among all of the possible scenarios is minimized. The relationship with other interval data minmax regret (IDMR) problems is investigated, the inapplicability of previous approximation methods is studied, regret evaluation is considered, and exact and heuristic solution methods are proposed and analyzed. The results of the proposed methods are compared in a computational experiment, showing the applicability of the method and the theoretical results to solve the problem under study. Additionally, these results are not only applicable to the problem in hand, but also to a more general class of problems. (C) 2018 Elsevier Ltd. All rights reserved.
Address [Pereira, Jordi] Univ Adolfo Ibanez, Dept Sci & Engn, Av Padre Hurtado 750,Off C216, Vina Del Mar, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-0548 ISBN Medium
Area Expedition Conference
Notes WOS:000427339800003 Approved
Call Number UAI @ eduardo.moreno @ Serial 838
Permanent link to this record
 
 
Author Pereira, J.; Alvarez-Miranda, E.
Title An exact approach for the robust assembly line balancing problem Type
Year (up) 2018 Publication Omega-International Journal Of Management Science Abbreviated Journal Omega-Int. J. Manage. Sci.
Volume 78 Issue Pages 85-98
Keywords Line balancing; Robust optimization; Lower bounds; Branch-and-bound
Abstract This work studies an assembly line balancing problem with uncertainty on the task times. In order to deal with the uncertainty, a robust formulation to handle changes in the operation times is put forward. In order to solve the problem, several lower bounds, dominance rules and an enumeration procedure are proposed. These methods are tested in a computational experiment using different instances derived from the literature and then compared to similar previous approaches. The results of the experiment show that the method is able to solve larger instances in shorter running times. Furthermore, the cost of protecting a solution against uncertainty is also investigated. The results highlight that protecting an assembly line against moderate levels of uncertainty can be achieved at the expense of small quantities of additional resources (stations). (C) 2017 Elsevier Ltd. All rights reserved.
Address [Pereira, Jordi] Univ Adolfo Ibanez, Fac Engn & Sci, Av Pedro Hurtado 750,Off A-215, Vina Del Mar, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-0483 ISBN Medium
Area Expedition Conference
Notes WOS:000433266700007 Approved
Call Number UAI @ eduardo.moreno @ Serial 872
Permanent link to this record
 
 
Author Pereira, J.
Title Modelling and solving a cost-oriented resource-constrained multi-model assembly line balancing problem Type
Year (up) 2018 Publication International Journal Of Production Research Abbreviated Journal Int. J. Prod. Res.
Volume 56 Issue 11 Pages 3994-4016
Keywords assembly line balancing; combinatorial optimisation; lower bound; heuristics; estimation of distribution algorithm
Abstract A line balancing problem considers the assignment of operations to workstations in an assembly line. While assembly lines are usually associated to mass production of standardised goods, their advantages have led to their widespread use whenever a product-oriented production system is applicable and the benefits of the labour division and specialisation are significant, even when some of its characteristics may deviate from classical assembly lines. In this work, we study a line balancing problem found in the textile industry in which the line must be balanced for multiple types of goods taking into account resource requirements. In order to solve the problem, a hybrid method that combines classical methods for line balancing with an Estimation of Distribution Algorithm is proposed. Computational experiments show that the new procedure improves upon the state of the art when compared using a benchmark set derived from the literature, as well as when compared using data from the manufacturer that originated this research work.
Address [Pereira, Jordi] Univ Adolfo Ibanez, Fac Engn & Sci, Vina Del Mar, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Taylor & Francis Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-7543 ISBN Medium
Area Expedition Conference
Notes WOS:000438403800013 Approved
Call Number UAI @ eduardo.moreno @ Serial 889
Permanent link to this record
 
 
Author Pereira, J.; Ritt, M.; Vasquez, O.C.
Title A memetic algorithm for the cost-oriented robotic assembly line balancing problem Type
Year (up) 2018 Publication Computers & Operations Research Abbreviated Journal Comput. Oper. Res.
Volume 99 Issue Pages 249-261
Keywords Line balancing; Cost-oriented line balancing; Robotic assembly line; Hybrid algorithms
Abstract In order to minimize costs, manufacturing companies have been relying on assembly lines for the mass production of commodity goods. Among other issues, the successful operation of an assembly line requires balancing work among the stations of the line in order to maximize its efficiency, a problem known in the literature as the assembly line balancing problem, ALBP. In this work, we consider an ALBP in which task assignment and equipment decisions are jointly considered, a problem that has been denoted as the robotic ALBP. Moreover, we focus on the case in which equipment has different costs, leading to a cost-oriented formulation. In order to solve the problem, which we denote as the cost-oriented robotic assembly line balancing problem, cRALBP, a hybrid metaheuristic is proposed. The metaheuristic embeds results obtained for two special cases of the problem within a genetic algorithm in order to obtain a memetic algorithm, applicable to the general problem. An extensive computational experiment shows the advantages of the hybrid approach and how each of the components of the algorithm contributes to the overall ability of the method to obtain good solutions. (C) 2018 Elsevier Ltd. All rights reserved.
Address [Pereira, Jordi] Univ Adolfo Ibanez, Fac Engn & Sci, Av Padre Hurtado 750,Off C216, Vina Del Mar, Chile, Email: jorge.pereira@uai.cl;
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-0548 ISBN Medium
Area Expedition Conference
Notes WOS:000442059400019 Approved
Call Number UAI @ eduardo.moreno @ Serial 907
Permanent link to this record
 
 
Author Averbakh, I.; Pereira, J.
Title Lateness Minimization in Pairwise Connectivity Restoration Problems Type
Year (up) 2018 Publication Informs Journal On Computing Abbreviated Journal INFORMS J. Comput.
Volume 30 Issue 3 Pages 522-538
Keywords combinatorial optimization; networks: scheduling; programming: branch and bound; network restoration; network construction; integrated network design and scheduling
Abstract A network is given whose edges need to be constructed (or restored after a disaster). The lengths of edges represent the required construction/restoration times given available resources, and one unit of length of the network can be constructed per unit of time. All points of the network are accessible for construction at any time. For each pair of vertices, a due date is given. It is required to find a construction schedule that minimizes the maximum lateness of all pairs of vertices, where the lateness of a pair is the difference between the time when the pair becomes connected by an already constructed path and the pair's due date. We introduce the problem and analyze its structural properties, present a mixed-integer linear programming formulation, develop a number of lower bounds that are integrated in a branch-and-bound algorithm, and discuss results of computational experiments both for instances based on randomly generated networks and for instances based on 2010 Chilean earthquake data.
Address [Averbakh, Igor] Univ Toronto Scarborough, Dept Management, Toronto, ON M1C 1A4, Canada, Email: averbakh@utsc.uturonto.ca;
Corporate Author Thesis
Publisher Informs Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1091-9856 ISBN Medium
Area Expedition Conference
Notes WOS:000449096000008 Approved
Call Number UAI @ eduardo.moreno @ Serial 924
Permanent link to this record
 
 
Author Osorio-Valenzuela, L.; Pereira, J.; Quezada, F.; Vasquez, O.C.
Title Minimizing the number of machines with limited workload capacity for scheduling jobs with interval constraints Type
Year (up) 2019 Publication Applied Mathematical Modelling Abbreviated Journal Appl. Math. Model.
Volume 74 Issue Pages 512-527
Keywords Scheduling; Parallel machines; Interval and workload constraints; Branch-and-price
Abstract In this paper, we consider a parallel machine scheduling problem in which machines have a limited workload capacity and jobs have deadlines and release dates. The problem is motivated by the operation of energy storage management systems for microgrids under emergency conditions and generalizes some problems that have already been studied in the literature for their theoretical value. In this work, we propose heuristic and exact algorithms to solve the problem. The heuristics are adaptations of classical bin packing heuristics in which additional conditions on the feasibility of a solution are imposed, whereas the exact method is a branch-and-price approach. The results show that the branch-andprice approach is able to optimally solve random instances with up to 250 jobs within a time limit of one hour, while the heuristic procedures provide near optimal solution within reduced running times. Finally, we also provide additional complexity results for a special case of the problem. (C) 2019 Elsevier Inc. All rights reserved.
Address [Osorio-Valenzuela, Luis] Univ Santiago Chile, Elect Engn Dept, Santiago, Chile, Email: luis.osoriov@usach.cl;
Corporate Author Thesis
Publisher Elsevier Science Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0307-904x ISBN Medium
Area Expedition Conference
Notes WOS:000474317800031 Approved
Call Number UAI @ eduardo.moreno @ Serial 1013
Permanent link to this record
 
 
Author Alvarez-Miranda, E.; Pereira, J.
Title On the complexity of assembly line balancing problems Type
Year (up) 2019 Publication Computers & Operations Research Abbreviated Journal Comput. Oper. Res.
Volume 108 Issue Pages 182-186
Keywords Line balancing; Complexity; Bin packing
Abstract Assembly line balancing is a family of combinatorial optimization problems that has been widely studied in the literature due to its simplicity and industrial applicability. Most line balancing problems are NP-hard as they subsume the bin packing problem as a special case. Nevertheless, it is common in the line balancing literature to cite [A. Gutjahr and G. Nemhauser, An algorithm for the line balancing problem, Management Science 11 (1964) 308-315] in order to assess the computational complexity of the problem. Such an assessment is not correct since the work of Gutjahr and Nemhauser predates the concept of NP-hardness. This work points at over 50 publications since 1995 with the aforesaid error. (C) 2019 Elsevier Ltd. All rights reserved.
Address [Alvarez-Miranda, Eduardo] Univ Talca, Dept Ind Engn, Curico, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-0548 ISBN Medium
Area Expedition Conference
Notes WOS:000471733300014 Approved
Call Number UAI @ eduardo.moreno @ Serial 1015
Permanent link to this record
 
 
Author Moreno, S.; Pereira, J.; Yushimito, W.
Title A hybrid K-means and integer programming method for commercial territory design: a case study in meat distribution Type
Year (up) 2020 Publication Annals Of Operations Research Abbreviated Journal Ann. Oper. Res.
Volume 286 Issue 1-2 Pages 87-117
Keywords Territorial design; Clustering; K-means; Integer programming; Case study
Abstract The objective of territorial design for a distribution company is the definition of geographic areas that group customers. These geographic areas, usually called districts or territories, should comply with operational rules while maximizing potential sales and minimizing incurred costs. Consequently, territorial design can be seen as a clustering problem in which clients are geographically grouped according to certain criteria which usually vary according to specific objectives and requirements (e.g. costs, delivery times, workload, number of clients, etc.). In this work, we provide a novel hybrid approach for territorial design by means of combining a K-means-based approach for clustering construction with an optimization framework. The K-means approach incorporates the novelty of using tour length approximation techniques to satisfy the conditions of a pork and poultry distributor based in the region of Valparaiso in Chile. The resulting method proves to be robust in the experiments performed, and the Valparaiso case study shows significant savings when compared to the original solution used by the company.
Address [Moreno, Sebastian; Pereira, Jordi; Yushimito, Wilfredo] Univ Adolfo Ibanez, Fac Engn & Sci, Av Padre Hurtado 750, Vina Del Mar, Chile, Email: sebastian.moreno@uai.cl;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0254-5330 ISBN Medium
Area Expedition Conference
Notes WOS:000511564300005 Approved
Call Number UAI @ eduardo.moreno @ Serial 1105
Permanent link to this record
 
 
Author Mejia, G.; Pereira, J.
Title Multiobjective scheduling algorithm for flexible manufacturing systems with Petri nets Type
Year (up) 2020 Publication Journal Of Manufacturing Systems Abbreviated Journal J. Manuf. Syst.
Volume 54 Issue Pages 272-284
Keywords Machine scheduling; Multi-objective optimization; Petri nets
Abstract In this work, we focus on general multi-objective scheduling problems that can be modeled using a Petri net framework. Due to their generality, Petri nets are a useful abstraction that captures multiple characteristics of real-life processes. To provide a general solution procedure for the abstraction, we propose three alternative approaches using an indirect scheme to represent the solution: (1) a genetic algorithm that combines two objectives through a weighted fitness function, (2) a non dominated sorting genetic algorithm (NSGA-II) that explicitly addresses the multi-objective nature of the problem and (3) a multi-objective local search approach that simultaneously explores multiple candidate solutions. These algorithms are tested in an extensive computational experiment showing the applicability of this general framework to obtain quality solutions.
Address [Mejia, Gonzalo] Univ La Sabana, Fac Engn, Campus Puente del Comun, Chia, Colombia, Email: gonzalo.mejia@unisabana.edu.co;
Corporate Author Thesis
Publisher Elsevier Sci Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0278-6125 ISBN Medium
Area Expedition Conference
Notes WOS:000521511500021 Approved
Call Number UAI @ eduardo.moreno @ Serial 1154
Permanent link to this record
 
 
Author Ritt, M.; Pereira, J.
Title Heuristic and exact algorithms for minimum-weight non-spanning arborescences Type
Year (up) 2020 Publication European Journal Of Operational Research Abbreviated Journal Eur. J. Oper. Res.
Volume 287 Issue 1 Pages 61-75
Keywords Minimum-weight non-spanning arborescence; Heuristic; Iterated Local Search; Branch-and-cut
Abstract We address the problem of finding an arborescence of minimum total edge weight rooted at a given vertex in a directed, edge-weighted graph. If the arborescence must span all vertices the problem is solvable in polynomial time, but the non-spanning version is NP-hard. We propose reduction rules which determine vertices that are required or can be excluded from optimal solutions, a modification of Edmonds algorithm to construct arborescences that span a given set of selected vertices, and embed this procedure into an iterated local search for good vertex selections. Moreover, we propose a cutset-based integer linear programming formulation, provide different linear relaxations to reduce the number of variables in the model and solve the reduced model using a branch-and-cut approach. We give extensive computational results showing that both the heuristic and the exact methods are effective and obtain better solutions on instances from the literature than existing approaches, often in much less time. (C) 2020 Elsevier B.V. All rights reserved.
Address [Ritt, Marcus] Univ Fed Rio Grande do Sul, Inst Informat, Av Bento Goncalves 9500, Porto Alegre, RS, Brazil, Email: marcus.ritt@inf.ufrgs.br;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0377-2217 ISBN Medium
Area Expedition Conference
Notes WOS:000541072800005 Approved
Call Number UAI @ eduardo.moreno @ Serial 1187
Permanent link to this record
 
 
Author Alvarez-Miranda, E.; Campos-Valdes, C.; Quiroga, M.M.; Moreno-Faguett, M.; Pereira, J.
Title A Multi-Criteria Pen for Drawing Fair Districts: When Democratic and Demographic Fairness Matter Type
Year (up) 2020 Publication Mathematics Abbreviated Journal Mathematics
Volume 8 Issue 9 Pages 27 pp
Keywords multi-criteria optimization; OR applications; malapportionment; districting; electoral system
Abstract Electoral systems are modified by individuals who have incentives to bias the rules for their political advantage (i.e., gerrymandering). To prevent gerrymandering, legislative institutions can rely on mathematical tools to guarantee democratic fairness and territorial contiguity. These tools have been successfully used in the past; however, there is a need to accommodate additional meanings of the term fairness within the electoral systems of modern democracies. In this paper, we present an optimization framework that considers multiple criteria for drawing districts and assigning the number of representatives. Besides some typical districting criteria (malapportionment and contiguity), we introduce novel criteria for ensuring territorial equilibrium and incentives for candidates to deploy their representation efforts fairly during their campaign and period in office. We test the method, which we denote as Multi-criteria Pen, in a recent and a forthcoming reform of the Chilean electoral system. The results show the potential of our tool to improve the current territorial design and offers insights on the motivations, objectives, and deficiencies of both reform plans.
Address [Alvarez-Miranda, Eduardo; Moreno-Faguett, Magas] Univ Talca, Fac Engn, Dept Ind Engn, Campus Curico, Curico 3341717, Chile, Email: ealvarez@utalca.cl;
Corporate Author Thesis
Publisher Mdpi Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2227-7390 ISBN Medium
Area Expedition Conference
Notes WOS:000580771600001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1246
Permanent link to this record
 
 
Author Alvarez-Miranda, E.; Chace, S.; Pereira, J.
Title Assembly line balancing with parallel workstations Type
Year (up) 2021 Publication International Journal Of Production Research Abbreviated Journal Int. J. Prod. Res.
Volume 59 Issue 21 Pages 6486-6506
Keywords Line balancing; parallel stations; dynamic programming; hybrid metaheuristic; matheuristic
Abstract The simple assembly line balancing problem (SALBP) considers work division among different workstations of a serially arranged assembly process to maximise its efficiency under workload (cumulative) and technological (precedence) constraints. In this work, we consider a variant of the SALBP which allows parallel workstations. To study the effect of parallel stations, we propose a new problem (the parallel station assembly line balancing problem or PSALBP) in which the objective is to minimise the number of parallel stations required to obtain the maximum theoretical efficiency of the assembly process. We study the complexity of the problem and identify a polynomially solvable case. This result is then used as a building block for the development of a heuristic solution procedure. Finally, we carry out a computational experiment to identify the characteristics of assembly lines that may benefit from station paralleling and to evaluate the performance of the proposed heuristic.
Address [alvarez-Miranda, Eduardo] Univ Talca, Fac Engn, Dept Ind Engn, Curico, Chile, Email: jorge.pereira@uai.cl
Corporate Author Thesis
Publisher Taylor & Francis Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-7543 ISBN Medium
Area Expedition Conference
Notes WOS:000569837900001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1243
Permanent link to this record
 
 
Author Cohen, Y.M.; Keskinocak, P.; Pereira, J.
Title A note on the flowtime network restoration problem Type
Year (up) 2021 Publication IISE Transactions Abbreviated Journal IISE Trans.
Volume 53 Issue 12 Pages 1351-1352
Keywords Scheduling; network construction planning; emergency restoration operations; deliveryman problem; traveling repairman problem
Abstract The flowtime network restoration problem was introduced by Averbakh and Pereira (2012) who presented a Minimum Spanning Tree heuristic, two local search procedures, and an exact branch-and-bound algorithm. This note corrects the computational results in Averbakh and Pereira (2012).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2472-5854 ISBN Medium
Area Expedition Conference
Notes WOS:000617722200001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1343
Permanent link to this record
 
 
Author Campos-Valdes, C.; Alvarez-Miranda, E.; Quiroga, MM; Pereira, J.; Duran, FL.
Title The Impact of Candidates' Profile and Campaign Decisions in Electoral Results: A Data Analytics Approach Type
Year (up) 2021 Publication Mathematics Abbreviated Journal Mathematics
Volume 9 Issue 8 Pages 902
Keywords Chilean parliamentary election; candidate profiles; campaign efforts; territorial deployment
Abstract In recent years, a wide range of techniques has been developed to predict electoral results and to measure the influence of different factors in these results. In this paper, we analyze the influence of the political profile of candidates (characterized by personal and political features) and their campaign effort (characterized by electoral expenditure and by territorial deployment strategies retrieved from social networks activity) on the electoral results. This analysis is carried out by using three of the most frequent data analyitcs algorithms in the literature. For our analysis, we consider the 2017 Parliamentary elections in Chile, which are the first elections after a major reform of the electoral system, that encompassed a transition from a binomial to a proportional system, a modification of the districts' structure, an increase in the number of seats, and the requirement of gender parity in the lists of the different coalitions. The obtained results reveal that, regardless of the political coalition, the electoral experience of candidates, in particular in the same seat they are running for (even when the corresponding district is modified), is by large the most influential factor to explain the electoral results. However, the attained results show that the influence of other features, such as campaign expenditures, depends on the political coalition. Additionally, by means of a simulation procedure, we show how different levels of territorial deployment efforts might impact on the results of candidates. This procedure could be used by parties and coalitions when planning their campaign strategies.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2227-7390 ISBN Medium
Area Expedition Conference
Notes WOS:000644524000001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1377
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Author Opazo, D.; Moreno, S.; Alvarez-Miranda, E.; Pereira, J.
Title Analysis of First-Year University Student Dropout through Machine Learning Models: A Comparison between Universities Type
Year (up) 2021 Publication Mathematics Abbreviated Journal Mathematics
Volume 20 Issue 9 Pages 2599
Keywords machine learning; first-year student dropout; universities
Abstract Student dropout, defined as the abandonment of a high education program before obtaining the degree without reincorporation, is a problem that affects every higher education institution in the world. This study uses machine learning models over two Chilean universities to predict first-year engineering student dropout over enrolled students, and to analyze the variables that affect the probability of dropout. The results show that instead of combining the datasets into a single dataset, it is better to apply a model per university. Moreover, among the eight machine learning models tested over the datasets, gradient-boosting decision trees reports the best model. Further analyses of the interpretative models show that a higher score in almost any entrance university test decreases the probability of dropout, the most important variable being the mathematical test. One exception is the language test, where a higher score increases the probability of dropout.
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Notes Approved
Call Number UAI @ alexi.delcanto @ Serial 1463
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