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INFORMS Nashville – 2016

459

2 - Effects Of Disjunctive Conic Cuts Within A Branch And Conic

Cut Algorithm

Sertalp Bilal Cay, Lehigh University,

sertalpbilal@gmail.com

Recently, Mixed Integer Second Order Cone Optimization (MISOCO) has gained

attention. This interest has been driven by the availability of efficient methods to

solve second order cone optimization (SOCO) problems and the wide range of

applications of MISOCO. In this work, we experiment with the recently

developed methodology of Disjunctive Conic Cuts (DCC). In particular, we test it

on variations of portfolio optimization problems within a Branch and Conic Cut

(BCC) framework. Our experiments show that our proposed methodology using

DCCs is effective in practical settings.

3 - A Rounding Procedure For A Maximally Complementary Solution

Of Second Order Conic Optimization

Ali Mohammad Nezhad, Lehigh,

alm413@lehigh.edu

The concept of optimal partition was originally introduced for linear optimization,

and later the concept was extended to second-order conic optimization. In this

paper, we present a rounding procedure, which uses optimal partition

information to generate a pair of maximally complementary optimal solutions.

The rounding procedure starts from a strictly interior solution, close to the

optimal set. It either gives an exact maximally complementary optimal solution in

strongly polynomial time, or provides a fast iterative procedure to approximate a

maximally complementary optimal solution.

WD12

104B-MCC

Recent Advances in Discrete Optimization

Sponsored: Optimization, Integer and Discrete Optimization

Sponsored Session

Chair: Andres Gomez Escobar, University of California, Berkeley, CA,

United States,

a.gomez@berkeley.edu

1 - Final Point Generalized Intersection Cuts

Aleksandr Mark Kazachkov, Carnegie Mellon University,

akazachk@cmu.edu

We introduce a new class of cuts for mixed-integer programming called final

point cuts. Generated from arbitrary valid disjunctions, this class is an extension

of the generalized intersection cut paradigm. We present theoretical and

computational results demonstrating the strength of these cuts as compared to

both standard intersection cuts and previous types of generalized intersection

cuts.

2 - Generating Cuts From The Ramping Polytope For The Unit

Commitment Problem

Jim Ostrowski, University of Tennessee,

jostrows@utk.edu

We present a perfect formulation for a single generator in the unit commitment

(UC) problem. This generator can have characteristics such as ramping

constraints, time-dependent start-up costs, and start-up/shut-down ramping. The

perfect formulation is polynomially large, so we use it to create a cut-generating

linear program for a single generator. We test the computational efficacy of these

cuts in a utility-scale UC MIP model, based on the FERC generator set and 2015

hourly data from PJM. These cuts may also beneficial for the more complex UC

models used by ISOs today because they reduce the enumeration needed to

enforce a generator’s technical constraints.

3 - Conic Quadratic Program With Indicator Variables

Hyemin Jeon, University of California Berkeley,

hyemin.jeon@berkeley.edu,

Alper Atamturk

We investigate a conic quadratic mixed 0-1 programming problem with on-off

constraints that arises from mean risk optimization. Analysis is conducted on the

properties of the optimal solutions of the problem and its relaxation. A class of

linear valid inequalities is derived by lifting the extended polymatroid inequalities

that are known to be highly effective for the pure 0-1 case. We report the result

of computational experiments to demonstrate the impact of the inequalities on

strengthening the continuous relaxation.

4 - Polymatroid Inequalities For Mixed-integer Second Order

Cone Programming

Andres Gomez, University of California Berkeley,

a.gomez@berkeley.edu

, Alper Atamturk

We propose valid inequalities for mixed-integer second order cones programs. We

show that the proposed inequalities completely describe the convex hull of a

single second order cone constraint. Moreover we show how to strengthen the

inequalities using other constraints of the optimization problem. We report

computational experiments on mixed-integer second-order cone programs, using

the proposed valid inequalities as cutting planes.

WD13

104C-MCC

Computational Optimization and Software

Sponsored: Optimization, Computational Optimization and Software

Sponsored Session

Chair: Robert J Vanderbei, Princeton University, Princeton, NJ, 08544,

United States,

rvdb@princeton.edu

Co-Chair: Hande Benson, Drexel University, LeBow College of

Business, Philadelphia, PA, 19104, United States,

benson@drexel.edu

1 - Cubic Regularization For Conjugate Gradient Minimization And

Symmetric Rank-one Methods

Hande Benson, Drexel University,

benson@drexel.edu

Regularization techniques have been used to help existing algorithms solve

“difficult” nonlinear optimization problems. Over the last decade, regularization

has been proposed to remedy issues with equality constraints and equilibrium

constraints, bound Lagrange multipliers, and identify infeasible problems. In this

talk, we will focus on the application of cubic regularization in the context of the

symmetric rank-one and conjugate gradient methods for nonlinear programming.

2 - Two New Efficient Algorithms For Compressed Sensing

Robert J Vanderbei, Princeton University,

rvdb@princeton.edu

We present two new approaches for solving large-scale compressed sensing

problems. The first approach uses the parametric simplex method to recover very

sparse signals by taking a small number of simplex pivots while the second

approach reformulates the problem using Kronecker products to achieve faster

computation via a sparser problem formulation. Numerical studies show that each

of these two algorithms are about 10 times faster than current state-of-the-art

methods.

3 - Using A Fast Projected Gradient Method To Solve Large Scale

Nonlinear Optimization Problems.

Igor Griva, George Mason University,

igriva@gmu.edu

Some modern nonlinear optimization problems have a large number of variables

and dense Hessians that makes challenging or impossible using second order

methods. We discuss how the fast projected gradient method can be used for

addressing optimization problems in machine learning, nonnegative least squares

and positive emission tomography reconstruction.

WD14

104D-MCC

Facility Location I

Contributed Session

Chair: David Mendez, Graduate Student, University of Tennessee, 2621

Morgan Circle, Knoxville, TN, 37996, United States,

dmendez@vols.utk.edu

1 - The Price Of Deception In Social Choice

James Patrick Bailey, Georgia Institute of Technology, 755 Ferst

Drive, NW, Unit 2401, Atlanta, GA, 30332, United States,

james.bailey@gatech.edu,

Craig Aaron Tovey

Classic impossibility theorems rule out strategy-proofness for all popular voting

rules, but is it wise to always settle for nothing with respect to manipulation? We

introduce a measure, the price of deception, of how much strategic voting could

alter an election outcome with respect to the winning criterion. We analyze this

measure for several standard voting rules and find significant differences among

them. We also analyze several standard cost functions for facility location, and

again find large differences. These results give good evidence that the price of

deception, like computational complexity, does offer finer distinctions of

manipulability than between ”yes” or ”no”.

2 - A Comprehensive Model For Location/allocation Of Maritime

Search And Rescue Vessels

Amin Akbari, PhD Candidate, Dalhousie University, 1104-1094

Wellington Street, Halifax, NS, B3H 2Z9, Canada,

amin.akbari@dal.ca,

Ronald P Pelot, H A Eiselt

The general methodology utilized in this study is building a mathematical model

to optimize the Location/Allocation of Maritime Search and Rescue Resources

with regard to several criteria such as primary and backup coverage, mean access

time and service equality. A multi-objective model is built to optimize the location

and response allocation of SAR resources with simultaneously taking several

objectives into account in order to achieve greater responsiveness and resource

utilization. Atlantic Canada serves as the area of the study. Sensitivity analyses are

performed on variable objective weights and other parameters to examine their

impact on the optimal solution.

WD14