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INFORMS Nashville – 2016

451

WC77

Legends E- Omni

Opt, Large Scale I

Contributed Session

Chair: Gerdus Benade, Carnegie Mellon University,

6235 Fifth Avenue, Apt B17, Pittsburgh, PA, 15232, United States,

gerdusbenade@gmail.com

1 - An Agglomerative Clustering Based Large-Scale Minimum Cost

Flow Algorithm

Yuan Zhou, PhD Candidate, University of Memphis,

174 Windover Cove, Apt 3, Memphis, TN, 38111, United States,

yuanzhou0924@gmail.com,

Stephanie Ivey

When the size of an input network exceeds computer hardware capabilities,

minimum cost flow (MCF) becomes problematic in terms of computational and

memory requirements. This research focuses on the large-scale MCF problem by

adopting a divide-and-conquer policy during the optimization process. We

propose an agglomerative clustering based tiling strategy which can ensure

consistency between local and global optimum solutions, decomposes the input

network into sub-networks, and then solves MCF in each sub-network

independently to reduce peak memory consumption and improve efficiency.

2 - Large Scale Scheduling Problems On Internet Of Things

Carlos Eduardo De Andrade, Senior Inventive Scientist, AT&T Labs

Research, 200 S Laurel Avenue, Room A5-1E33, Middletown, NJ,

07748, United States,

cea@research.att.com

The number of connected devices has been increasing exponentially over past

years. Such devices do not only use the network for their main purposes, such as

collect and share data but also in the maintenance mode for updates. We present

a scheduling problem to deal with massive download updates on millions of

devices connected to radio networks. One of the main challenges of this problem

is the fact of the devices are mobile and can connect to several access points in the

network over the time, and the server usually can not control the download

process other than suggesting a start time to the download. The problem also

includes other constraints such as network and server capacities, and devices

limitations.

3 - Optimum Product Introduction And Strategic Capacity Planning

Including Demand And Price Cannibalization

Gorkem Yilmaz, Assistant Professor, Ozyegin University,

Cekmekoy, Istanbul, 34794, Turkey,

gorkem.yilmaz@ozyegin.edu.tr

, Amaia Lusa Garcia,

Ernest Benedito

In literature, product introduction and strategic capacity planning typically

address optimal timing, pricing decisions and capacity management

independently regardless of demand and price cannibalization effects. We develop

a Mixed Integer Linear Program (MILP) model for solving strategic capacity

planning and product introduction problems, simultaneously, including demand

and price cannibalization. With dynamic demand and pricing senario, we analyze

several numerical examples to display the interaction between demand and price.

4 - Benders Decomposition And Column-and-row Generation

For Solving Large-scale Linear Programs With

Column-dependent-rows

Kerem Bulbul, Associate Professor, Sabanci University, Faculty of

Engineering & Natural Sciences, Orhanli, Tuzla, Istanbul, 34956,

Turkey,

bulbul@sabanciuniv.edu

, Ilker S Birbil, Ibrahim Muter

We study a general class of LP problems - known as problems with column-

dependent-rows (CDR-P). These LPs feature two sets of constraints with mutually

exclusive groups of variables in addition to a set of structural linking constraints,

in which variables from both groups appear together. The number of linking

constraints grows very quickly with the number of variables, which motivates

generating both columns and their associated linking constraints simultaneously

on-the-fly. The structure of CDR-P is amenable to Benders decomposition and

leads to an effective approach. The unavailability of a full description of the

Benders subproblem over the iterations is our main theoretical challenge.

5 - The Branching Dual Of A Discrete Optimization Problem

Gerdus Benade, Carnegie Mellon University, 6235 Fifth Avenue,

Apt B17, Pittsburgh, PA, 15232, United States,

gerdusbenade@gmail.com

, John Hooker

We formulate the branching dual of a discrete optimization problem as

maximizing an inferred lower bound over the space of partial search trees. We

identify a class of optimization problems with limited information transfer for

which a greedy node selection rule is approximately optimal. A computational

study compares the efficiency of the branching dual with other methods for

proving bounds on the minimum bandwidth problem. It is found that the

branching dual requires significantly fewer nodes than the alternatives to prove a

given bound.

WC78

Legends F- Omni

Health Care, Modeling

Contributed Session

Chair: Harshal Lowalekar, Indian Institute of Management-Indore,

Prabandh Shikhar, Rau-Pithampur Road, Indore, 453331, India,

lwlherschelle@gmail.com

1 - A Microsimulation Cost-effectiveness Analysis Of Nalmefene To

Reduce Heavy Alcohol Consumption In An Alcohol-dependent

Canadian Population

Estefania Ruiz Vargas, Ivey Business School, 1255 Western Rd,

London, ON, N6G 0N1, Canada,

eruizvar@uwo.ca,

Richard Zur,

Greg Zaric

Nalmefene is an opioid antagonist believed to reduce the analgesic and positive

reward effect of alcohol. A microsimulation of alcohol consumption was

developed to determine if nalmefene combined with psychosocial support is cost-

effective for reducing alcohol consumption in an alcohol-dependent Canadian

population. We considered a number of different nalmefene treatment

approaches, and evaluated the public health benefit of implementing nalmefene

as a pharmacological intervention for alcohol dependence in Canada.

2 - Managing A Multi-physician Clinic With Heterogeneous Patients

Wen-Ya Wang, San Jose State University, San Jose, CA,

United States,

wenya.wang@sjsu.edu

, Hao-Wei Chen

This paper focuses on the physician panel design problem of determining the

patient composition (i.e. panel size and types of patient) for physician panels. In

particular, we investigate how clinics would allocate a given pool of two types of

patient flows that have different appointment patterns (i.e. low frequent/routine

service vs. high frequent/complex care needs). We identify the characteristics of

patient and capacity allocation strategies from the perspectives of the clinics and

the patients

3 - A Markovian Model For Blood Components Production System

Harshal Lowalekar, Indian Institute of Management-Indore,

Prabandh Shikhar, Rau-Pithampur Road, Indore, 453331, India,

lwlherschelle@gmail.com

We develop a Markovian model for the production of major components such as

red blood cells, platelets and plasma from whole blood at a blood bank. The

supply quantity of whole blood is assumed to be a random variable. Using the

Markovian approach we determine the optimal target collection level for whole

blood and the percentage of whole blood to be separated into components.

WC79

Legends G- Omni

Opt, Combinatorial I

Contributed Session

Chair: Christopher John Wishon, Ph.D. Candidate, Arizona State

University, Tempe, AZ, United States,

cwishon@asu.edu

1 - Reformulation-linearization Technique Application On Integer

Programming Models For Organ Exchange Program

Seokhyun Chung, Korea University, Seoul, Korea, Republic of,

tcheong@korea.ac.kr,

Junsang Yuh, Taesu Cheong

Kidney exchange allows a potential living donor whose kidney is incompatible

with the intended recipient to donate a kidney to another patient so that the

donor’s recipient receives a compatible kidney from another donor. This can be

modeled as maximum weight cycle packing problems in a directed graph. In this

study, we verify relationship between existing models via reformulation-

linearization technique (RLT), and develop a new integer programming model for

kidney exchange program by implementing the RLT. In addition, we devise new

integer programming model for liver exchange program, which has distinct

character. Moreover, we enhance the integer programming model by applying

RLT.

2 - Solution Approaches To Network Design Problems With Decision

Dependent Uncertainty

Nathaniel Richmond, University of Iowa, 446 4th Avenue, Iowa

City, IA, 52241, United States,

nathaniel-richmond@uiowa.edu

,

Pavlo A Krokhmal, Dmytro Matsypura

Robust network design problems have many important practical applications, and

for this reason are well-represented in the operations research literature.

However, until the last decade very little research has examined stochastic robust

network design problems in which the user’s decisions affect the underlying

probability distribution of the random outcome. In this talk, we present a model

for the stochastic network design problem with decision-dependent uncertainties.

We discuss computational challenges and explore different solution approaches.

In particular, we present a metaheuristic algorithm that draws from strengths of

GRASP and genetic algorithms.

WC79