2016 INFORMS Annual Meeting Program

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INFORMS Nashville – 2016
453
WC82
Broadway G- Omni
Networks and Graphs III
Contributed Session
Chair: Monica Gentili, IPAT, Georgia Institute of Technology,
75 5th Street NW, Suite 600, Atlanta, GA, 30308, United States,
1 - The Impact Of Visual Aesthetics On The Utility, Affordance,
And Readability Of Network Graphs
Patrick Michael Dudas, Faculty Research Associate, Pennsylvania
State University, 691 Wiltshire Drive, State College, PA, 16803,
United States,
Network visualizations facilitate the understanding of relationships, where
research classically focuses more on readability. While existing studies are mostly
concerned with the readability of topological mapping (based on different
layouts), this work focuses on how visual aesthetics affect users’ understanding of
network structures by both readability (direct utility) and perceived affordance
(indirect utility). Accompanied with these measures are eye-tracking data and
retrospective think-aloud protocol to provide qualitative context to these visual
strategies. Our study contributes to the understanding of visual aesthetics in
network visualization design.
2 - An Algorithm To Design LDPC Codes With Low Error Floor In
Communication Systems
Banu Kabakulak, Bogazici University, Istanbul, Turkey,
, Z. Caner Ta kın, Ali Emre Pusane
In a digital communication system, information is sent from one place to another
over a noisy communication channel using binary symbols (bits). Original
information is encoded by adding redundant bits, which are then used by low-
density parity-check (LDPC) codes to detect and correct the errors. Error
correction capability of an LDPC code is severely degraded due to harmful
structures such as cycles in its bipartite graph representation (Tanner graph).
Hence, we can achieve a low error floor when there are no small cycles in Tanner
graph. We introduce an integer programming formulation for maximizing the
smallest cycle size in Tanner graph. We propose a branch-and-cut algorithm for its
solution.
3 - Critical Effect Of Dependence Clusters On Cascading Failures In
Network Systems
Jian Zhou, PhD Student, Rutgers University, Bevier Road, Buell
Apt, 0378, 2145 Bpo Way, Piscataway, NJ, 08854, United States,
, Ning Huang, David W Coit
Current failure models focusing on network load dynamics provide powerful
approaches to analyze cascading failures in networks. However, previous studies
don’t take the impacts of dependencies among network nodes beyond network
connection into account. Recent research show that dynamics of networks
considering dependencies differ greatly from that with only connectivity links.
Based on a mixed cascading failure model for networks including load dynamics
and dependencies, we analyze numerically the influences of dependence clusters
of nodes on failure mechanism in networks subjecting to random failures. How
network topology affects the robustness of such networks are also investigated.
4 - The Interval Transportation Problem
Monica Gentili, Associate Professor, University of Louisville,
132 Eastern Parkway, Louisville, KY, 40205, United States,
, Raffaele Cerilli, Ciriaco D’Ambrosio
The basic transportation problem (TP) deals with the transportation of goods from
a set of supply points to a set of demand points so as to minimize linear
transportation costs. The interval transportation problem extends TP to take into
consideration uncertainty in the supply and demand when they are expressed in
interval forms. We analyze the set of the optimal solutions of the problem and
apply a heuristic algorithm to explore it.
WC83
Broadway H- Omni
Supply Chain Optimization III
Contributed Session
Chair: Ethan Malinowski, University at Buffalo, 8 Affinity Lane,
Apt 251E, Buffalo, NY, 14215, United States,
1 - Stochastic Models For Strategic Sourcing In Energy Industry
Ashesh Kumar Sinha, University of Wisconsin-Madison, 1402
Regent St Apt 731A, Madison, WI, 53711, United States,
, Ananth Krishnamurthy
We analyze the supply chain in oil and gas industries that manufacture custom-
engineered equipment. We consider a multi-period centralized system and
decentralized system where the product can be made either at the in-house
manufacturing facility or at dedicated facilities of the external supplier. At each
time period, the manufacturer and the supplier decide their capacity levels and
the production quantity to satisfy a random demand. Using stochastic models, we
analyze optimal production and capacity investment decisions, and also analyze
the inefficiencies in the decentralized system.
2 - A Joint Supplier Selection And Lot-sizing Problem With Quality
Constraint Under An All-unit Discount Environment
Xin Li, Pennsylvania State University, University Park, PA,
16802, United States, , Jose Antonio Ventura,
M. Jeya Chandra
This paper considers a joint supplier selection and lot-sizing problem, where
suppliers are capacitated and offer all-unit discounts. The product’s perfect rate
differs among suppliers and a minimum overall acceptable perfect rate exists. A
cyclic order schedule is employed and the set of selected suppliers, and
corresponding order quantities and frequencies are determined accordingly so
that the total cost per time unit is minimized. A mixed-integer nonlinear
mathematical model is presented and analyzed. A dynamic programming
algorithm is proposed to solve the discretized version of the model.
3 - Liquid Helium Global Supply Chain Modeling And Optimization
Ethan Malinowski, University at Buffalo, 8 Affinity Lane,
Apt 251 E, Buffalo, NY, 14215, United States,
, Mark Karwan, Banu Gemici-Ozkan,
Jose M Pinto
The global supply chain for liquid helium presents a complex structure due to
increasing foreign demand, elaborate recovery techniques, and costly forms of
distribution. Although the task contains parallels to the vehicle routing and
traveling salesmen problems, supply requirements and problem-specific network
constraints require a unique optimization model. We develop a large-scale
discrete time, path-based integer-programming model which solves optimally
using CPLEX. Computational results implementing a rolling horizon structure and
testing against historical data are presented.
WC84
Broadway J- Omni
Supply Chain, Risk III
Contributed Session
Chair: Irina Dolinskaya, Northwestern University, 2145 Sheridan Road,
Tech Institute, M235, Evanston, IL, 60208-3119, United States,
1 - A Robust Decision-Making In a Supply Chain Under
Disruption Risks
Tadeusz J Sawik, Professor and Chair, AGH University of Science
& Technology, Al. Mickiewicza 30, Krakow, 30059, Poland,
A robust decision-making in a supply chain under local and regional disruption
risks is considered. The robustness refers to an equitably efficient average and
worst-case performance, which reflects the decision-makers common
requirement to maintain an equally good performance of a supply chain under
different conditions. The problem objective is to select suppliers of parts and
schedule customer orders for products to equitably optimize average and worst-
case cost or service level. The robust solution is obtained using the ordered
weighted averaging aggregation of the expected value and the conditional value-
at-risk.
2 - Investigating WOMs Behind Crisis: Contingent Negative Spillover
Effect In Supply Chain Partnership
Xiaolun Wang, PhD Candidate, Fudan University,
670 Guoshun Road, Yangpu District, Shanghai, 200433, China,
Cenying Yang, Cheng Zhang
This paper aims to investigate mechanism that governs the vertical spillover effect
of crisis from stricken firm to its supply chain partners. Based on Accessibility-
Diagnosticity theory, we explain why and when WOM could contribute to the
negative spillover, that is, guilt by association mechanism for large downstream
partners and information asymmetry mechanism for small upstream partners.
Based on a merged, multi-sources, and longitudinal dataset from Capital IQ, and
Sina Microblog, we apply PVAR model with GMM estimators to capture the
dynamic interactions between WOM attributes (volume/valence/dispersion) and
abnormal return of the supply chain partners.
3 - Supplier Assessment Policies In Total Cost Auctions
Karca Aral, Asst. Professor, Syracuse University, 721 University
Avenue, Syracuse, NY, 13244, United States,
We address the trade-off between compulsory and voluntary supplier assessments
in a procurement auction. Compulsory assessments enable buyers to learn the
total cost of ownership (TCO) before selecting a supplier; however, this leads to
decreased supplier competition. In contrast, voluntary assessments increase
supplier competition, however provide less information on the TCO.
WC84