2016 INFORMS Annual Meeting Program

WB81

INFORMS Nashville – 2016

WB81 Broadway F- Omni Health Care, Strategies II Contributed Session

WB82 Broadway G- Omni Networks and Graphs II Contributed Session Chair: Christopher Claypool, Louisiana State University, 1315 Woodcliff Drive, Baton Rouge, LA, 70815, United States, cclayp1@lsu.edu 1 - Modelling And Simulation Of The Formation Of Social Networks Song Chew, Associate Professor, Southern Illinois University- Edwardsville, SIUE, Edwardsville, IL, 62026, United States, schew@siue.edu The objective of this study is to determine the distribution of the degree of a node in a social network formed when a newborn node connects to a fixed number of randomly chosen existing nodes and any pair of chosen nodes are connected if they are not already connected. 2 - Exact And Heuristic Algorithms For Finding An Efficient Theme Park Tour Richard Forrester, Associate Professor of Mathematics, Dickinson College, Department of Mathematics, College and Louther Street, Carlisle, PA, 17013, United States, forrestr@dickinson.edu, Danny Rivers, James Midkiff, Elizabeth Bouzarth, Kevin Hutson The problem of efficiently touring a theme park is an instance of the well-known Time-Dependent Traveling Salesman Problem (TDTSP). In this talk we describe a mixed-integer programming method and two different metaheuristic approaches (genetic algorithm and tabu search) that can be used to find an efficient solution to the TDTSP. We provide computational experience for when our algorithms are utilized to find tours of Disney World and Hershey Park. Chair: Wang Shukun, Huazhong University of science and technology, Luoyu Road 1037, Wuhan, 430074, China, wsk17951@163.com 1 - Optimization Of Lignocellulosic Biomass To Biofuel Supply Chains With Mobile Pelleting Nibal Albashabsheh, PhD Student, Kansas State University, 1604 Roof Drive, Apt 101, Manhattan, KS, 66502, United States, nibal15@ksu.edu, Jessica Heier Stamm The low density of lignocellulosic biomass (LB) results in high costs associated with biomass transportation, storage, and handling in the biomass-to-biofuel supply chain (BBSC). Mobile pelleting machines provide an as-yet-unexplored opportunity to increase LB density. A comprehensive BBSC optimization model that integrates mobile pelleting is developed to minimize the overall cost of producing ethanol from LB. The proposed model addresses the unique challenges of having different baling forms of LB and of the potential to use mobile pelleting machines. A sensitivity analysis is conducted to identify the impact of important parameters on decisions related to biomass densification. 2 - Supply Chain Coordination Under Price Sensitive Demand: A Game Theoretic Approach Barbara Venegas Quintrileo, Penn State University, University Park, PA, 16802, United States, bbv105@psu.edu, Jose Antonio Ventura This research explores the coordination between a supplier and a buyer within a decentralized supply chain, through the use of quantity discounts in a game theoretic model. We propose both non-cooperative and cooperative approaches considering that the product traded experiences a price sensitive demand, uniquely defined by an elasticity coefficient. In the first case we study the dynamics of the game from the supplier’s perspective as the leader obtaining a Stackelberg equilibrium. In the second case we formulate a cooperative model where decisions are taken jointly, emulating a centralized decision making process. 3 - Flexible Production Resources And Capacity Utilization Rates: A Robust Optimization Perspective Aldis Jakubovskis, University of Missouri - St. Louis, Saint Louis, MO, United States, jakubovskisa@missouri.edu We apply robust optimization in the context of optimal choices of product- dedicated and flexible capacities in a spatial setting under demand uncertainty. Total capacity may not be fully utilized because of the distinction between largest and costliest demand realizations. More flexible capacity can increase utilization; however, our results report less than full capacity utilization even using flexible capacity only. WB83 Broadway H- Omni Supply Chain Optimization II Contributed Session

Chair: Michelle M. Alvarado, Visiting Assistant Professor, Texas A&M University, 3131 TAMU, College Station, TX, 77843, United States, michelle.alvarado@tamu.edu 1 - Nursing Home Rating System Inspection And Audit Xu Han, Research Assistant, University of Connecticut School of Business, 2100 Hillside Road, Storrs, CT, 06269, United States, xu.han@business.uconn.edu CMS’s nursing home rating system gives ratings by combining inspection and self- reported measures, which are subject to inflation. In this paper, we optimize CMS’s inspection and audit mechanism to control inflation and improve system performance. We formulate the inspection problem by using an innovative graph- based method, and test it with CMS data. Our result shows that the measure currently being inspected is optimal only if an effective audit mechanism is in place. We then add nursing homes’ reactions to audit into consideration and conduct a simulation to study the optimal parameter settings. Our result suggests that CMS should set a moderate extensiveness of audit, and a high punishment rate. 2 - Calling For Care? The Risky Proposition Of Teletriage In Healthcare Demand Management Ozden Engin Cakici, Assistant Professor, American University, 4400 Massachusetts Avenue, NW, Washington, DC, 20016, United States, cakici@american.edu, Alex Mills A major challenge in healthcare is the need to match the patient’s medical condition to the right provider. Patients are medically inexperienced, so their decision can lead to costly service mismatches. We model the effect of adding telephone triage by a “nurseline” on the patient’s decision as a POMDP. We examine the effect of adding a free or low cost nurseline on the patient’s decision and on accessibility to an appointment. We show that a patient’s choice is a threshold policy based on her belief about her illness severity. We also show that nurseline may reduce cost and increase quality of care for a risk-neutral patient, but it may lead to an opposite behavior for a risk-seeking patient. 3 - Association Between Reserve Capacity And Surge Event Resiliency In Community Hospitals Raymond L Smith, Doctoral Candidate, North Carolina State University, 318 Weycroft Grant Drive, Cary, NC, 27519, United States, rlsmith5@ncsu.edu This paper explores the association between the reserve capacity maintained by a community hospital and the operational recovery period following a patient surge event. The study examines whether increasing the ready reserve bed capacity results in greater benefits over other alternatives that include clinical area expansion. A model of a community hospital is used to explore the effects of varied unit capacity on congestion and recovery duration. Results indicate that increasing the ready reserve bed capacity and contingency surge capacity can provide the most competitive outcomes; however, outcomes are demonstrated to be vulnerable to resource activation responsiveness. 4 - A Multi-method Simulation Model Of Hospital Readmission Reduction Strategies Michelle M. Alvarado, Visiting Assistant Professor, Texas A&M University, 3131 TAMU, College Station, TX, 77843, United States, michelle.alvarado@tamu.edu, Mark Alan Lawley In 2012 the Centers for Medicare and Medicaid Services implemented a penalty- only system to reduce the rate of hospital readmissions. We develop a multi-method simulation model to assess the impact of alternative readmission reduction strategies, including an incentive-only reimbursement model. The multi-method model combines agent-based simulation of the patient population with system dynamics of the healthcare reimbursement system. Impact is assessed by improvements in the quality of care and reduction in 30-day hospital readmission rates. Results indicate that the incentive-only model is preferred to the penalty-only model under certain conditions.

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