Informs 2015

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INFORMS Philadelphia – 2015
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2 - Optimizing Community Healthcare Coverage in Remote Liberia
through an Integer Linear Programming Model
Paige Von Achen, Northwestern University, Sheridan Road,
Evanston, IL, United States of America,
Here we present a collaborative effort by the NGO, Last Mile Health, and
Northwestern University to aid the expansion of healthcare accessibility
throughout remote Liberia. Two integer linear programming models are
developed that determine (1) the location assignments of healthcare workers and
their supervisors and (2) the routing of the supervisors. We highlight the benefits
of rigorous data collection and using a cross-disciplinary team to provide proper
scoping and representation of a given problem.
3 - A Faster Algorithm for the Resource Allocation Problem with
Convex Cost Functions
Chao Qin, PhD Candidate, Northwestern University, 2145
Sheridan Road, Evanston, IL, 60208, United States of America,
, Cong Shi, Huanan Zhang
We revisit the classical resource allocation problem with general convex objective
functions, subject to an integer knapsack constraint. This class of problems is
fundamental in discrete optimization and arises in a wide variety of applications.
In this paper, we propose a novel polynomial-time divide-and-conquer algorithm
and prove that it has a computational complexity of O(n log n log N), which
outperforms the best known polynomial-time algorithm with O(n (log N)^2).
4 - Integrated Optimization of Aircraft Utilization and On-time
Performance
Beril Burçak, Bilkent University, 1972. Sok. Melis Sit. D Blok No:
8, Ankara, Turkey, , Alaz Ata Senol,
Hakan Sentörk, Ayça Karatepe, Osman Rauf Karaaslan,
Dr. Kemal Güler, Kaan Yavuz
This paper concerns the decision-support system created for Pegasus Airlines of
Turkey, designed to improve the company’s two key performance indicators;
aircraft utilization and on-time performance. A unique approach is introduced to
tackle the tradeoff between these two indicators via mathematical modeling.
Significant improvements in operational performance and customer satisfaction
are achieved as the previously manually done flight scheduling process has been
automatized.
5 - Routing Optimization of a Drone for Agricultural Inspections
Kaan Telciler, Koc University, Rumelifeneri yolu Koç University,
Main Campus Sariyer, Istanbul, Turkey, ,
Ezgi Karakas, Cagan Urkup
Drones can be used in various areas with developing drone technologies. In order
to provide an automized usage for drones, there is a need of routing approach.
We developed a mathematical model and routing heuristic for drones which
considers recharge stations, battery limit, wind changes, restricted regions and
sequential routes. We used cluster first, route second approach for heuristic. In
several datasets and cases, we obtained near-optimal routing in feasible times.
SB27
27-Room 404, Marriott
Multi-objective Choice Problems
Sponsor: Multiple Criteria Decision Making
Sponsored Session
Chair: Ozlem Karsu, Bilkent University, Bilkent Universitesi, Endustri
Muhendisligi, Ankara, 06800, Turkey,
1 - Two Approaches for Inequity-averse Sorting
Ozlem Karsu, Assistant Professor, Bilkent University,
Bilkent, Ankara, Turkey,
We consider multi-criteria sorting problems where the decision maker(DM) has
equity such problems each alternative represents an allocation of an
outcome over multiple entities. We propose two sorting algorithms that are
different from the ones in the current literature in the sense that they apply to
cases where the DM’s preference relation satisfies anonymity and convexity
properties. We illustrate their use by sorting countries into groups based on their
income distributions.
2 - A Preference-based Approach to Multi-objective
Feature Selection
Muberra Ozmen, Middle East Technical University, Industrial
Engineering Department, Ankara, 06800, Turkey,
, Gulsah Karakaya, Murat Koksalan
In feature selection problems, one or more subsets of available features that best
characterize the output of interest are selected. In this study, we develop a
preference-based approach for the multi-objective feature selection problems
considering objectives such as maximizing classification performance and
minimizing the number of selected features. We test the approach on several
instances.
SB28
28-Room 405, Marriott
Contingent Mechanisms
Cluster: Auctions
Invited Session
Chair: Rakesh Vohra, University of Pennsylvania, 3718 Locust Walk,
Philadelphia, United States of America,
1 - Implementation with Contingent Contracts
Rahul Deb, Assistant Professor, University of Toronto, 150 St.
George St, Toronto, ON, m5s3g7, Canada,
We study dominant strategy incentive compatibility with contingent contracts
where the payoff of each agent is observed by the principal and can be contracted
upon. We characterize outcomes implementable by linear contracts and provide a
foundation for them by showing that, in finite type spaces, every social choice
function (SCF) that can be implemented using a more general nonlinear
contingent contract can also be implemented using a linear contract.
2 - Market Selection and the Information Content of Prices
Mehmet Ekmekci, Boston College, 140 Commonwealth Avenue,
Chestnut Hill, MA, 02467, United States of America,
, Alp Atakan
In an economy where buyers with unit demand decide to purchase one of two
possible goods which are traded in two distinct markets. The goods traded within
each market are identical, common-value objects and the price formation process
as a large uniform-price auction. imperfectly informed bidders choose to
participate in one of the markets. If market frictions lead to uncertain gains from
trade in any of the two markets, then there is no equilibrium where prices
aggregate information.
3 - Contingent Mechanisms with Endogenous Information
Yunan Li, University of Pennsylvania, 160 McNeil Building, 3718
Locust Walk, Philadelphia, PA, 19104, United States of America,
I study the auction design problem when buyers can make payments contingent
on their ex-post returns. An example is selling a company using securities like
shares. I consider settings where buyers can covertly acquire information at a cost
before the auction. I find that auctions using steeper securities provide lower
incentives for agents to acquire information, and thus may generate lower
revenues. I also study the design of the optimal linear contingent mechanism
with endogenous information.
4 - Participation and Unbiased Pricing in CDS
Settlement Mechanisms
Ahmad Peivandi, Participation and Unbiased Pricing in CDS
Settlement Mechanisms, Georgia State University, 35 Broad St,
Atlanta, GA, United States of America,
Credit default swaps are insurance contracts on default. Currently, there are over
20 trillion USD worth of outstanding CDS contracts. These contracts are settled
through a centralized market that has been criticized for underpricing the asset. In
this paper, I take a mechanism design approach and characterize robust
settlement mechanisms that deliver an unbiased price for the asset. A second
contribution of my paper is a new notion of the core for games of incomplete
information. This is particularly relevant here because participation in the
settlement mechanism cannot be compelled.
SB29
29-Room 406, Marriott
A Collection of State of the Art Analytics Models
and Methods
Sponsor: Analytics
Sponsored Session
Chair: Michael Katehakis, Professor And Chair, Rutgers University,
100 Rockafeller Rd., Piscataway, NJ, 08854, United States of America,
1 - The [ Map(t)/ Ph(t)/ Inf ] k Queueing System and Network
Ira Gerhardt, Manhattan College, 4513 Manhattan College
Parkway, Riverdale, NY, 10471, United States of America,
Michael Taaffe, Barry Nelson
We generalize a numerically exact method for evaluating time-dependent
moments of the entities in a Ph(t) /Ph(t) / \Inf queueing system to the MAP(t)
/Ph(t) / \Inf queueing system, and show that these same results can be used to
analyze the multiclass [MAP(t) /Ph(t) / \Inf]^K queueing network system. Finally
we show that the covariance of the number of entities at different nodes and
times may be described by a single closed differential equation.
SB27