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INFORMS Philadelphia – 2015

289

2 - Optimal Averaging Schemes for Stochastic

Approximation Methods

Farzad Yousefian, Postdoctoral Research Associate, Penn State,

333 Logan Ave., Apt. 307, State College, PA, 16801, United States

of America,

szy5@psu.edu

, Angelia Nedich, Uday Shanbhag

We develop optimal weighted averaging stochastic approximation schemes for

solving stochastic variational inequality problems. We show that the gap function

associated with the averaged sequence diminishes to zero at the optimal rate. We

also develop a window-based variant of this scheme that displays the optimal rate

and the superiority in the constant factor of the bound comparing to the classic

averaging schemes. Preliminary numerical results on a stochastic Nash-Cournot

game are presented.

3 - Adaptive Sampling Line Search for Local Simulation Optimization

Raghu Pasupathy, Associate Professor, Department of Statistics,

Purdue University, 250 N University Street, West Lafayette, IN,

47907, United States of America,

pasupath@purdue.edu

,

Fatemeh Hashemi

We present an algorithm for continuous simulation optimization that combines

adaptive sampling ideas with a classical line search method from deterministic

nonlinear programming. We will discuss theoretical properties and a brief

example.

4 - Noisy Collective Nonconvex Optimization

Mengdi Wang, Assistant Professor, Princeton University, 302

Trinity Ct #2, Princeton, NJ, 08540, United States of America,

mengdiw@princeton.edu

Paper not available at this time.

TB14

14-Franklin 4, Marriott

Joint Session OPT/ICS: Stochastic Programming:

Progressive Hedging and Related Methods

Sponsor: Optimization/Optimization Under Uncertainty

Sponsored Session

Chair: Jonathan Eckstein, Professor, Rutgers University, 100 Rockafeller

Road, Piscataway, NJ, 08854, United States of America,

jeckstei@rci.rutgers.edu

1 - Scalable Lower and Upper Bounding Techniques for Stochastic

Unit Commitment with Progressive Hedging

Jean-paul Watson, Sandia National Laboratories,

P.O. Box 5800, MS 1326, Albuquerque, United States of America,

jwatson@sandia.gov,

David Woodruff, Sarah Ryan

We describe configurations of a scenario-based decomposition strategy for solving

the stochastic unit commitment problem, based on the progressive hedging

algorithm. We consider both upper and lower bounding aspects of progressive

hedging in the mixed-integer case, and demonstrate parameterizations that yield

extremely tight optimality gaps for 100-generator cases and moderately tight

optimality gaps for 350-generator cases.

2 - Progressive Hedging and Dual Decomposition

David Woodruff, UC Davis, One Shields Avenue, Davis, CA,

95616, United States of America,

dlwoodruff@ucdavis.edu

The PH algorithm proposed by Rockafellar and Wets and the DDSIP algorithm

proposed by Caroe and Schultz can both be thought of as primal-dual algorithms

and both can be used to address stochastic mixed-integer programs. In this talk I

describe work with numerous co-authors to use the two algorithms together. In

addition we describe an algebraic modeling language (Pyomo) interface to DDSIP

that is useful with, or without, PH.

3 - Asynchronous Projective Progressive-hedging-like Stochastic

Programming Decomposition Methods

Jonathan Eckstein, Professor, Rutgers University, 100 Rockafeller

Road, Piscataway, NJ, 08854, United States of America,

jeckstei@rci.rutgers.edu

We present a class of stochastic programming algorithms based on new

Combettes-Eckstein monotone operator splitting methods. Unusually, these

splitting methods need to re-solve only a subset of the subproblems at each

iteration, using boundedly outdated information. Applying these techniques to

stochastic programming yields methods that resemble progressive hedging, but

can operate in a fully asynchronous manner. Convergence is guaranteed under

the same conditions as for progressive hedging.

TB15

15-Franklin 5, Marriott

Recent Advances in Nonlinear Programming

Sponsor: Optimization/Nonlinear Programming

Sponsored Session

Chair: Hande Benson, Associate Professor, Drexel University, LeBow

College of Business, Philadelphia, PA, 19104, United States of America,

hvb22@drexel.edu

1 - Solving the Problem of Portfolio VAR Minimization as a Nonlinear

Program

Arun Sen, Director, Navigant Consulting, 685 3rd Avenue,

14th Floor, New York, NY, 10017, United States of America,

arunsen@alumni.princeton.edu

Minimizing Value at Risk (VAR) is challenging as the optimization problem is

non-convex. In previous work the problem was formulated as an MPEC

(mathematical program with equilibrium constraints), that was solved using

branch-and-bound techniques. We show that the same MPEC can be solved

effectively as a nonlinear program, specifically by use of interior-point methods,

and that this a flexible approach that is easily able to incorporate additional

constraints on the optimal portfolio.

2 - Fast Algorithms for LAD Lasso Problems

Robert Vanderbei, Princeton University, ORFE,

Sherrerd Hall, Princeton, NJ, 08544,

United States of America,

rvdb@princeton.edu

We will present a new algorithm for the LAD Lasso problem. We will compare

this new algorithm against existing state-of-the-art algorithms.

3 - Cubic Regularization for First-order Methods

David Shanno, RUTCOR - Rutgers University (Emeritus),

Rutgers University, New Brunswick, NJ, United States of

America,

shannod@comcast.net,

Hande Benson

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 the conjugate gradient methods for nonlinear

programming.

4 - Value Driven Design Delegation - An Optimization Model

Vinod Cheriyan, Enova International, 1255 S Michigan Ave.

Apt 3711, Chicago, IL, 60605, United States of America,

vinod.cheriyan@gmail.com

, Chris Paredis, Anton Kleywegt

Rather than satisfaction of stakeholder needs, the Value Driven Design approach

focuses on maximization of economic value. For large, complex systems, the

systems designer maximizes the value by delegating detailed design to many

subsystem teams. We study the convergence properties of such a value-driven,

delegation-based system design process, where knowledge is distributed. We

model the design as an optimization problem. We propose an algorithm and show

that it converges to a critical point.

TB16

16-Franklin 6, Marriott

Various Aspects of Mixed Integer Conic Optimization

Sponsor: Optimization/Linear and Conic Optimization

Sponsored Session

Chair: Sertalp Cay, Lehigh University, 200 W Packer Ave, Bethlehem,

PA, 18015, United States of America,

sec312@lehigh.edu

1 - Portfolio Optimization Problems with Cone Constraints and

Discrete Decisions

Umit Saglam, Assistant Professor, East Tennessee State University,

Department of Management and Marketing, College of Business

and Technology, Johnson City, TN, 37614, United States of

America,

saglam@etsu.edu

, Hande Benson

In this study we consider both single-period and multiperiod portfolio

optimization problems based on the Markowitz (1952) mean/variance

framework. Our model is aggregated from current

literature.We

solve these

models with a MATLAB based Mixed Integer Linear and Nonlinear Optimizer

(MILANO). We have devised and implemented the first solution method for such

problems and demonstrate its efficiency on large-scale portfolio optimization

models.We

also provide substantial improvement in runtimes.

TB16