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INFORMS Philadelphia – 2015

42

SA15

SA15

15-Franklin 5, Marriott

Nonlinear Optimization in Energy Systems

Sponsor: Optimization/Nonlinear Programming

Sponsored Session

Chair: Nai-Yuan Chiang, Argonne National Laboratory, 9700 South

Cass Avenue, Lemont, IL, United States of America,

nychiang@mcs.anl.gov

Co-chair: Yankai Cao,Ph.d. Student, Purdue University, FRNY G053B,

480 Stadium Mall Drive, West Lafayette IN 47907, United States of

America,

cao142@purdue.edu

1 - Clustering-Based Interior-Point Strategies for Convex

Stochastic Programs

Yankai Cao, PhD Student, Purdue University, FRNY G053B, 480

Stadium Mall Drive, West Lafayette, IN, 47907, United States of

America,

cao142@purdue.edu

, Victor M. Zavala, Carl Laird

We present a clustering-based interior-point strategy for two-stage stochastic

programs. The key idea is to perform adaptive clustering of scenarios inside the

solver. The resulting compressed KKT system is much smaller and is used as a

preconditioner. We derive spectral and error properties for the preconditioner. We

also describe our parallel implementation and demonstrate that high compression

rates of 87% and speedups of 30 are achievable for electricity market clearing

problems.

2 - Arc Search Methods for Linearly Constrained Optimization

Nick Henderson, Research Associate and Instructor, Stanford

University, Stanford, CA,

nwh@stanford.edu

We present an arc search algorithm for linearly constrained optimization. The

method constructs and searches along smooth arcs that satisfy a small set of

properties. When second derivatives are used, the method is shown to converge

to a second-order critical point. We discuss use of arc search in Quasi-Newton

methods and different strategies for handling constraints.

3 - A Progressive Method to Solve Large-scale AC Optimal Power

Flow with Discrete Variables

Maxime Fender, Optimization Consultant, Artelys Canada Inc.,

2001 Boulevard Robert-Bourassa, #1700, Montréal, QC, H3A

2A6, Canada,

maxime.fender@artelys.com

, Manuel Ruiz,

Jean Maeght, Alexandre Marié, Patrick Panciatici

This study on power system networks aims to produce a dynamic simulation

based security assessment taking into account uncertainties. An extended OPF

without any guarantee on feasibility leads to the resolution of a Mixed-Integer

NonLinear Problem, very challenging, and even harder to solve when the

problem is not convex. A custom filtering method which tries to explain

infeasibilities and uses the nonlinear solver KNITRO to reformulate discrete

variables into nonlinear constraints is proposed.

4 - A Robust Approach to Chance Constrained Optimal Power Flow

with Renewable Generation

Yury Dvorkin, PhD Student/Research Assistant, University of

Washington, 185 Stevens Way NE, Paul Allen Center, Room

AE104R, Seattle, WA, 98195, United States of America,

iouridvorkin@gmail.com

, Miles Lubin, Scott Backhaus

We formulate a Robust Chance Constrained (RCC) OPF that accounts for

uncertainty in the parameters of these probability distributions by allowing them

to be within an uncertainty set. The RCC OPF is solved using a scalable cutting-

plane algorithm. We evaluate the RRC OPF on a modified BPA test system, which

includes 2209 buses and 176 controllable generators. Deterministic, chance

constrained (CC), and RCC OPF formulations are compared using several cost and

reliability metrics.

SA16

16-Franklin 6, Marriott

Topics in Optimization

Sponsor: Optimization/Linear and Conic Optimization

Sponsored Session

Chair: John Mitchell, Professor, Rensselaer Polytechnic Institute,

Mathematical Sciences Dept, Troy, NY, 12180, United States of America,

mitchj@rpi.edu

1 - A Rounding Procedure for a Maximally Complementary Solution

of Semidefinite Optimization Problems

Ali Mohammad Nezhad, PhD Student, Lehigh University, 200

West Packer Ave., Industrial and Systems Engineering Dept.,

Bethlehem, PA, 18015, United States of America,

ali.mohammadnezhad@gmail.com,

Tamás Terlaky

In this paper, we deal with the identification of optimal partitioning in

semidefinite optimization. We derive some bounds on the condition numbers of

the problem using the first order theory of reals and estimate the magnitude of

the eigenvalues in the vicinity of the central path, which depends on the degree

of singularity of the optimality conditions. We then present a rounding procedure

for the solution of an interior point method to get a maximally complementary

solution.

2 - Convex and Structured Nonconvex Stochastic Optimization with

Stochastic Constraints

Zhiqiang Zhou, University of Florida, 2330 SW Williston RD,

Apt3034, Gainesville, FL, 32608, United States of America,

brianzhou1991@gmail.com,

Guanghui Lan

We present a new stochastic approximation (SA) algorithm to minimize a class of

convex or nonconvex objective functions subject to certain expectation

constraints. We show that this algorithm exhibits the optimal rates of

convergence in expectation and with high probability under different conditions.

Some numerical results are provided for portfolio management and machine

learning.

3 - Benders Decomposition for Discrete-constrained Problems with

Complementarity Constraints

John Mitchell, Professor, Rensselaer Polytechnic Institute,

Mathematical Sciences Dept, Troy, NY, 12180, United States of

America,

mitchj@rpi.edu,

Jong-shi Pang, Andreas Waechter,

Francisco Jara-Moroni

We discuss a logical Benders decomposition approach to discrete-constrained

mathematical programs with complementarity constraints. This is an extension of

our prior approach to linear and quadratic programs with complementarity

constraints. The inclusion of discrete and binary constraints broadens the

applicability of the approach.

SA17

17-Franklin 7, Marriott

Social Network Modeling and Optimization

Sponsor: Optimization/Network Optimization

Sponsored Session

Chair: Alexander Nikolaev, Assistant Professor, University at Buffalo

(SUNY), 312 Bell Hall, Buffalo, NY, 14260-2050,

United States of America,

anikolae@buffalo.edu

1 - Seed Selection Scheduling for Long-term Campaign Planning on

Large Social Networks

Mohammadreza Samadi, PhD Candidate, University at Buffalo

SUNY, 327 Bell Hall, Buffalo, NY, 14260, United States of

America,

msamadi@buffalo.edu,

Alexander Nikolaev,

Nagi Rakesh

The influence maximization problem lies in finding a set of seeds that can

optimally initiate a diffusion-driven cascade. We explore flexible, time-dependent

seed activation solutions for long-term intervention/campaign planning on

networks. The Seed Selection Scheduling Problem (SSSP) is that of selecting an

optimal policy for seed activation over a finite time horizon under knapsack

constraints. The ideas from the wireless sensor scheduling domain are used to

tackle SSSP on large networks.

2 - Critical Nodes in Network Cohesion

Alexander Veremyev, University of Florida, 1350 N Poquito Road,

Shalimar, FL, United States of America,

averemyev@ufl.edu

,

Oleg Prokopyev, Eduardo Pasiliao

We consider a class of critical nodes detection problems that involves

minimization of a graph cohesion measure (e.g., graph efficiency or harmonic

average geodesic distance, Harary index, characteristic path length,

communication utility) that depends on the actual pairwise distances between

nodes in the remaining graph after nodes removal. We derive linear integer

programming formulations along with additional enhancements, and develop an

exact iterative algorithm to solve this problem.

3 - Detecting Cliques of Maximum and Minimum Centrality: Methods

and Applications

Chrysafis Vogiatzis, Assistant Professor, North Dakota State

University, 1410 14th Avenue North, Room 202 Civil & Industrial

Engineering, Fargo, ND, 58102, United States of America,

chvogiat@ufl.edu

, Alexander Veremyev

In this talk, we consider the problem of finding the most and least “influential” or

“influenceable” cliques in graphs based on three classical centrality measures:

degree, closeness, and betweenness. In addition to standard betweenness, we also

consider its optimistic and pessimistic counterparts along with a new metric for

cluster closeness, namely residual closeness centrality. Applications discussed

include analysis of information and social networks, and results on the stock

market graph.