419 research outputs found

    Manual for conducting socioeconomic surveys through Pocket Portable Device Assistants (PDAs) and personal computers

    Get PDF
    Socioeconomic environment, Surveys, Computers, Computer software, Data collection, PDAs, Personal computers, Research Methods/ Statistical Methods, U40, E10,

    Finding the nucleolus of any n-person cooperative game by a single linear program

    Get PDF
    In this paper we show a new method for calculating the nucleolus by solving a unique minimization linear program with Oð4n Þ constraints whose coefficients belong to f−1; 0; 1g. We discuss the need of having all these constraints and empirically prove that they can be reduced to Oðkmax2n Þ, where kmax is a positive integer comparable with the number of players. A computational experience shows the applicability of our method over (pseudo)random transferable utility cooperative games with up to 18 playersThe authors want to thank Javier Arin, Safae El Haj Ben Ali, Guillermo Owen and Johannes H. Reijnierse for their useful and valuable help. The research of the authors has been partially supported by the projects FQM-5849 (Junta de Andalucia \ FEDER), and by the project MTM2010-19576-C02-01 (MICINN, Spain). This paper was written while the second author was enjoying a grant for a short postdoctoral research visit at the Instituto Universitario de Investigacion de Matematicas de la Universidad de Sevilla (IMUS). Special thanks are due to one anonymous referee for his/her valuable comments.Puerto Albandoz, J.; Perea Rojas Marcos, F. (2013). Finding the nucleolus of any n-person cooperative game by a single linear program. Computers and Operations Research. 40(10):2308-2313. https://doi.org/10.1016/j.cor.2013.03.01123082313401

    On minimax and Pareto optimal security payoffs in multicriteria games

    Full text link
    [EN] In this paper, we characterize minimax and Pareto-optimal security payoff vectors for general multicriteria zero-sum matrix games, using properties similar to the ones that have been used in the single criterion case. Our results show that these two solution concepts are rather similar, since they can be characterized with nearly the same sets of properties. Their main difference is the form of consistency that each solution concept satisfies. We also prove that both solution concepts can transform into each other, in their corresponding domains. (C) 2017 Elsevier Inc. All rights reserved.We would like to thank Dr. Francisco R. Fernandez for his useful comments on earlier versions of this paper. The authors also want to acknowledge the financial support from grants FQM-5849 (Junta de Andalucia\FEDER) and MTM2016-74983-C02-01, MTM2013-46962-C02-01 (MICINN, Spain).Puerto Albandoz, J.; Perea Rojas Marcos, F. (2018). On minimax and Pareto optimal security payoffs in multicriteria games. Journal of Mathematical Analysis and Applications. 457(2):1634-1648. https://doi.org/10.1016/j.jmaa.2017.01.002S16341648457

    Greedy and K-Greedy algoritmhs for multidimensional data association

    Full text link
    [EN] The multidimensional assignment (MDA) problem is a combinatorial optimization problem arising in many applications, for instance multitarget tracking (MTT). The objective of an MDA problem of dimension dNd\in\Bbb{N} is to match groups of dd objects in such a way that each measurement is associated with at most one track and each track is associated with at most one measurement from each list, optimizing a certain objective function. It is well known that the MDA problem is NP-hard for d3d\geq3. In this paper five new polynomial time heuristics to solve the MDA problem arising in MTT are presented. They are all based on the semi-greedy approach introduced in earlier research. Experimental results on the accuracy and speed of the proposed algorithms in MTT problems are provided. © 2006 IEEE.This research was supported by a Marie Curie fellowship of the European Community program "Improving Human Research Potential and the Socio-economic Knowledge Base" under Contract HPMI-CT-2002-00221.Perea Rojas Marcos, F.; De Waard, HW. (2011). Greedy and K-Greedy algoritmhs for multidimensional data association. IEEE Transactions on Aerospace and Electronic Systems. 47(3):1915-1925. doi:10.1109/TAES.2011.59372731915192547

    Designing Rapid Transit Network Design with Alternative routes

    Full text link
    The aim of this paper is to propose a model for the design of a robust rapid transit network. In this paper, a network is said to be robust when the effect of disruption on total trip coverage is minimized. The proposed model is constrained by three different kinds of flow conditions. These constraints will yield a network that provides several alternative routes for given origin–destination pairs, therefore increasing robustness. The paper includes computational experiments which show how the introduction of robustness influences network desig

    Models and matheuristics for the unrelated parallel machine scheduling problem with additional resources

    Full text link
    [EN] In this paper we analyze a parallel machine scheduling problem in which the processing of jobs on the machines requires a number of units of a scarce resource. This number depends both on the job and on the machine. The availability of resources is limited and fixed throughout the production horizon. The ob- jective considered is the minimization of the makespan. We model this problem by means of two integer linear programming problems. One of them is based on a model previously proposed in the literature. The other one, which is based on the resemblance to strip packing problems, is an original contribution of this paper. As the models presented are incapable of solving medium-sized instances to optimality, we propose three matheuristic strategies for each of these two models. The algorithms proposed are tested over an extensive computational experience. Results show that the matheuristic strategies significantly outperform the mathematical models.The authors are supported by the Spanish Ministry of Economy and Competitiveness, under project "SCHEYARD - Optimization of Scheduling Problems in Container Yards" (No. DPI2015-65895-R), partially financed with FEDER funds. Thanks are due to our colleagues Eva Vallada and Ful Villa, for their useful suggestions. Special thanks are due to three anonymous referees which have significantly contributed to the improvement of the manuscript. Apart from accompanying on-line materials, interested readers can download more contents from http://soa.iti.es/problem-instances, like the instances used, software for generating instances and all the binaries of the algorithms tested in this paper. We also provide complete solutions, full tables of results and the statistics software files to replicate all results and plots. Additional explanations are also provided in "how-to" text files.Perea Rojas Marcos, F.; Fanjul Peyró, L.; Ruiz García, R. (2017). Models and matheuristics for the unrelated parallel machine scheduling problem with additional resources. European Journal of Operational Research. 260(2):482-493. https://doi.org/10.1016/j.ejor.2017.01.002S482493260

    Simultaneous frequency and capacity setting for rapid transit systems with a competing mode and capacity constraints

    Get PDF
    The railway planning problem consists of several consecutive phases: network design, line planning, timetabling, personnel assignment and rolling stocks planning. In this paper we will focus on the line planning process. Traditionally, the line planning problem consists of determining a set of lines and their frequencies optimizing a certain objective. In this work we will focus on the line planning problem context taking into account aspects related to rolling stock and crew operating costs. We assume that the number of possible vehicles is limited, that is, the problem that we are considering is a capacitated problem and the line network can be a crowding network. The main novelty in this paper is the consideration of the size of vehicles and frequencies as variables as well as the inclusion of a congestion function measuring the level of in-vehicle crowding. Concretely, we present the problem and an algorithm to solve it, which are tested via a computational experience

    Designing robust rapid transit networks with alternative routes

    Get PDF
    The aim of this paper is to propose a model for the design of a robust rapid transit network. In this paper, a network is said to be robust when the effect of disruption on total trip coverage is minimized. The proposed model is constrained by three different kinds of flow conditions. These constraints will yield a network that provides several alternative routes for given origin–destination pairs, therefore increasing robustness. The paper includes computational experiments which show how the introduction of robustness influences network design.Unión Europea FP6-021235-2Ministerio de Fomento PT2007-003-08CCPPMinisterio de Educación y Ciencia TRA2005-09068-C03-01 MTM2006-15054Ministerio de Ciencia e Innovación TRA2008-06782-C02-01Natural Sciences and Engineering Research Council of Canada 39682-0

    Acceptance Ordering Scheduling Problem: The impact of an order-portfolio on a make-to-order firm’s profitability

    Get PDF
    Firms’ growth, the darling measure of investors, comes from higher revenues. Thus, sales and marketing departments make extreme efforts to accept as many customer orders as possible. Unfortunately, not all orders contribute equally to profits, and some orders may even reduce net profits. Thus, saying no (i.e., not accepting an order) may be a necessary condition for net profits growth. For understanding the impact of rejecting orders on profitability, we propose an order acceptance and scheduling problem (OAS). Although the OAS has extensively been studied in the literature, there is still some gap between these papers and real-life problems in industry. In an attempt to close that gap, the OAS we propose considers orders revenues, machines costs, holding costs and tardiness costs. We develop a mixed integer linear programming (MILP) model for solving this problem. Since the complexity of the problem makes it impossible for the MILP to solver large-scale instances, we also propose a metaheuristic algorithm. Numerical experiments show that the metaheuristic finds good quality solutions in short computational times. In the last part of the paper we confirm some managerial insights: higher holding and tardiness costs imply a lower acceptance of orders, forcing production has a concave negative impact on net profits, and accurately estimating costs is essential for good planning
    corecore