Informs Annual Meeting 2017

TD12

INFORMS Houston – 2017

TD12

TD13

332B Public Transportation Sponsored: Transportation Science & Logistics Sponsored Session

332C Game Theory Contributed Session Chair: Ulas Ozen, Ozyegin University, Istanbul, Turkey, ulas.ozen@ozyegin.edu.tr 1 - A Principal-agent Problem with Heterogeneous Demand Distributions Wenbo (Selina) Cai, New Jersey Institute of Tech, Mec 308, University Heights, Newark, NJ, 07102, United States, cai@njit.edu, Dashi Singham Mechanism design problems optimize contract from a principal to agents who have private information about their demands for a product or a service. We study the implications of uncertainty in agents’ demands on the principal’s contracts. Specifically, we consider the setting where agents’ demands follow heterogeneous distributions and the principal offers a menu of contracts stipulating quantities and transfer payments for each demand distribution. We present analytical solutions for the special case of two distributions and a method for deriving analytical solutions from numerical solutions. We show that the optimal solution depends on the ordering of the demand levels across distributions. 2 - Responsible Supplier Selection Wenqing Zhang, University of Minnesota Duluth, 1318 Kirby Drive, Labovitz School of Business and Economics, Duluth, MN, 55812, United States, zhangwenqing@gmail.com, Jiujiu Shen, Huaping Gong This paper studies the pricing and sourcing choices in a two-echelon supply chain selling a procure-to-stock product to a price-sensitive and social welfare conscious market. We assume that the manufacturer can decide between two different sourcing options, i.e., insourcing and outsourcing, without friction costs. We illustrate the significance of the social image in a company’s sourcing decision. Our results explain, from a managerial point of view, whether or why, if applicable, low manpower cost countries are losing their competitive advantages. 3 - On the Core of M-attribute Cooperative Games Ulas Ozen, Associate Professor, Ozyegin University, Cekmekoy Campus, Nisantepe District, Orman Street, Istanbul, 34794, Turkey, ulas.ozen@ozyegin.edu.tr, Marco Slikker We study cooperation between several parties by pooling their m-types of resources to improve overall system performance, i.e., maximize total profit or minimize total costs. This type of cooperation leads to ‘‘m-attribute’’ games whose characteristic function is embedded in an m-dimensional function. We derive the necessary and sufficient conditions on the latter function such that all embedded games have a non-empty core. We also study other important properties of m- attribute games, e.g., convexity. 332D Patient Flow Management Sponsored: Manufacturing & Service Oper Mgmt, Healthcare Operations Sponsored Session Chair: Pengyi Shi, Purdue University, West Lafayette, IN, 47907, United States, shi178@purdue.edu Co-Chair: Nan Liu, Columbia University, New York, NY, 10032, United States, nl2320@columbia.edu 1 - Design and Analysis of Integrated Practice Units Douglas Morrice, University of Texas at Austin, Irom Department, 2110 Speedway Stop B6500, Austin, TX, 78712-1750, United States, douglas.morrice@mccombs.utexas.edu, Jonathan F. Bard, Karl Koenig An important strategy for delivering high-value, patient-centered care is for providers to organize into dedicated teams around a patient’s condition and provide a full cycle of care in an Integrated Practice Unit (IPU). We discuss the use of simulation and optimization to design and analyze IPUs. We illustrate our work with a Joint Pain IPU example. TD14

Chair: Mor Kaspi, École Polytechnique Fédérale de Lausanne (EPFL), EPFL-ENAC-INTER-LUTS, Room GC C2 389, Lausanne, CH-1015, Switzerland, morkaspi@poat.tau.ac.il 1 - Pass Programs and Loyalty Programs for Transit Agencies Mehdi Nourinejad, Postdoctoral Fellow, University of Toronto, St. George, Toronto, ON, L4B4G6, Canada, mehdi.nourinejad@mail.utoronto.ca, Amir Gandomi, Joseph Y.J. Chow, Matthew Roorda The proliferation of smart cards in public transportation has paved the way for successful implementation of two prominent discount policies: pass programs and loyalty programs. While pass programs have been around as early as the 1970s, loyalty programs are only becoming popular. In a loyalty program, riders get a discount on their fare if they complete a given number of trips within a time period. In this paper, we derive the optimal pass and loyalty program, and we investigate if one is superior. The pass program is superior for public transit agencies because it offers a higher social welfare, but the loyalty program is better for private agencies because it generates a higher profit. 2 - Optimal Bus Type and Number of Bus Stops in Public Transportation under Random Demand and Sustainability Adoption Levels with in the Community Elif Elcin Gunay, Iowa State University, Ames, IA, United States, eekabeloglu@gmail.com, Kijung Park, Gul Kremer This study develops a stochastic optimization model for deciding both the bus size and the number of bus stops to minimize the public transportation cost under randomness of demand and sustainability adoption levels in a community. In addition to transportation costs, we consider social costs, i.e. waiting and riding time of passengers in the model. We model social cost as a factor of the sustainability adoption levels. The number of bus stops and the bus sizes are adapted subject to the fluctuation in demand for different bus lines. In the numerical study, we consider different levels of demand and sustainability adoption levels and conduct a trade-off analysis between decreasing cost and social costs. 3 - A Heuristic Algorithm for Improving the Quality of Service in Paratransit by Considering Schedule Reliability Chung-Wei Shen, Assistant Professor, National Cheng Kung University, Tainan, Taiwan, cwshen@mail.ncku.edu.tw With the increasing aging and disabled population and the trend toward on- demand transportation, more and more people are relying on door-to-door shared transportation services. Few studies have been conducted on the quality of service for operating dial-a-ride (DAR) services for elderly/disabled passengers. In this paper, we consider a fundamental feature determining the quality of service of DAR services: the reliability of the trip schedule. An algorithm integrating the measure of schedule reliability will be developed such that it is efficient enough to solve large-sized problems. The objective of this paper is to better understand the tradeoffs between reliability and operational costs. 4 - Designing Lines and Frequencies for Public Transportation using Benders Decomposition Mor Kaspi, Postdoctoral Researcher, Ecole Polytechnique Federale de Lausanne (EPFL), EPFL-ENAC-INTER-LUTS, Room GC C2 389, Lausanne, CH-1015, Switzerland, mor.kaspi@epfl.ch, Martin Repoux, Nikolas Geroliminis We formulate an integrated line selection, vehicle assignment and passenger assignment problem for public transportation as an MILP. The quality of service is represented by the total journey time of passengers, composed of riding times and waiting times at origin and transfer stations. The resulting formulation is of high dimensionality. In order to solve large instances, we develop a Benders decomposition approach in which solutions of the sub-problems are obtained in linear time. The effectiveness of our approach is demonstrated using instances derived from a real-world application.

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