Author
Erhan Erkut
Other affiliations: University of Alberta, Bilkent University, Boğaziçi University
Bio: Erhan Erkut is an academic researcher from Özyeğin University. The author has contributed to research in topics: Population & Heuristic. The author has an hindex of 36, co-authored 72 publications receiving 5022 citations. Previous affiliations of Erhan Erkut include University of Alberta & Bilkent University.
Papers published on a yearly basis
Papers
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TL;DR: A survey of the maximization location models in the Operations Research literature is contained, and a synthesis of the solution procedures with emphasis on similarities and differences is presented.
385 citations
TL;DR: The coding effort and the computational effort required are minimal, making the algorithm a good choice for practical applications requiring quick solutions, or for upper-bound generation to speed up optimal algorithms.
Abstract: We propose a new genetic algorithm for a well-known facility location problem. The algorithm is relatively simple and it generates good solutions quickly. Evolution is facilitated by a greedy heuristic. Computational tests with a total of 80 problems from four different sources with 100 to 1,000 nodes indicate that the best solution generated by the algorithm is within 0.1% of the optimum for 85% of the problems. The coding effort and the computational effort required are minimal, making the algorithm a good choice for practical applications requiring quick solutions, or for upper-bound generation to speed up optimal algorithms.
346 citations
TL;DR: An overview of the prevailing models for hazardous materials transport is provided, and the question "Does it matter how the authors quantify transport risk" is addressed.
Abstract: The transport of hazardous materials is an important strategic and tactical decision problem. Risks associated with this activity make transport planning difficult. Although most existing analytical approaches for hazardous materials transport account for risk, there is no agreement among researchers on how to model the associated risks. This paper provides an overview of the prevailing models, and addresses the question "Does it matter how we quantify transport risk?" Our empirical analysis on the U.S. road network suggests that different risk models usually select different "optimal" paths for a hazmat shipment between a given origin-destination pair. Furthermore, the optimal path for one model could perform very poorly under another model. This suggests that researchers and practitioners must pay considerable attention to the modeling of risks in hazardous materials transport.
343 citations
TL;DR: This work proposes a formulation in which the various constraints of political districting problems are integrated into a single multicriteria function, by means of a tabu search and adaptive memory heuristic.
267 citations
TL;DR: The heuristic, developed to get an initial lower bound, finds an optimal solution for most of the random test problems, and an extension to the basic problem that allows for preselected points, which may correspond to existing facility locations.
267 citations
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01 May 1975
TL;DR: The Fundamentals of Queueing Theory, Fourth Edition as discussed by the authors provides a comprehensive overview of simple and more advanced queuing models, with a self-contained presentation of key concepts and formulae.
Abstract: Praise for the Third Edition: "This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented."IIE Transactions on Operations EngineeringThoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than presenting a narrow focus on the subject, this update illustrates the wide-reaching, fundamental concepts in queueing theory and its applications to diverse areas such as computer science, engineering, business, and operations research.This update takes a numerical approach to understanding and making probable estimations relating to queues, with a comprehensive outline of simple and more advanced queueing models. Newly featured topics of the Fourth Edition include:Retrial queuesApproximations for queueing networksNumerical inversion of transformsDetermining the appropriate number of servers to balance quality and cost of serviceEach chapter provides a self-contained presentation of key concepts and formulae, allowing readers to work with each section independently, while a summary table at the end of the book outlines the types of queues that have been discussed and their results. In addition, two new appendices have been added, discussing transforms and generating functions as well as the fundamentals of differential and difference equations. New examples are now included along with problems that incorporate QtsPlus software, which is freely available via the book's related Web site.With its accessible style and wealth of real-world examples, Fundamentals of Queueing Theory, Fourth Edition is an ideal book for courses on queueing theory at the upper-undergraduate and graduate levels. It is also a valuable resource for researchers and practitioners who analyze congestion in the fields of telecommunications, transportation, aviation, and management science.
2,562 citations
TL;DR: The literature is surveyed to identify potential research directions in disaster operations, discuss relevant issues, and provide a starting point for interested researchers.
1,431 citations
TL;DR: This review reports on literature which explicitly addresses the strategic nature of facility location problems by considering either stochastic or dynamic problem characteristics, with applications ranging across numerous industries.
1,321 citations
TL;DR: In this article, the authors present a review of the state-of-the-art in continuous location models and network location models, mixed-integer programming models, and applications for distribution system design.
935 citations
TL;DR: This paper proposes a classification scheme and looks at a number of problem variants in location-routing: a relatively new branch of locational analysis that takes into account vehicle routing aspects.
907 citations