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INFORMS Nashville – 2016

480

WD77

Legends E- Omni

Opt, Large Scale II

Contributed Session

Chair: Helder Inacio, Sabre Holdings Inc, 3150 Sabre Drive,

Southlake, TX, 76092, United States,

Helder.Inacio@Sabre.com

Nonnegative Matrix Factorization

Haoran Sun, Iowa State University, Ames, IA, United States,

hrsun@iastate.edu

, Qingjiang Shi, Songtao Lu, Mingyi Hong,

Meisam Razaviyayn

Symmetric nonnegative matrix factorization (SNMF) is equivalent to computing a

symmetric nonnegative low rank approximation of a data similarity matrix. It

inherits the good interpretability of the NMF technique and performs better on

nonlinearly separable data. In this paper, we focus on the algorithmic aspect of

the SNMF problem and propose simple inexact block coordinate decent methods,

leading to both serial and parallel algorithms. The proposed algorithms have

guaranteed stationary convergence and can efficiently handle large-scale and/or

sparse SNMF problems. Extensive simulations verify the effectiveness of the

proposed algorithms compared to recent state-of-the-art algorithms.

Multivariate Gaussian Random Fields To Large Data Sets

Sam Davanloo, The Ohio State University, Columbus, OH, United

States,

sdt144@vt.edu

, Necdet Serhat Aybat, Enrique Del Castillo

This paper generalizes the Sparse Precision matrix Selection (SPS) algorithm,

proposed by Davanloo et al. (2015),for estimating scalar Gaussian Random Field

(GRF) models, to the multivariate, second-order stationary case under a separable

covariance function. Theoretical convergence rates for the estimated covariance

matrix and for the estimated parameters of the correlation function are

established. Numerical simulation results validate our theoretical findings. Data

segmentation is used to handle large data sets.

Neural Network

Xi He, Lehigh University, 837 Cedar Hill Drive, Allentown, PA,

18109, United States,

xih314@lehigh.edu

, Martin Takac

It is well known that the optimization problem derived from deep neural network

is always in high dimension with high non-convexity. In this paper, we revisit

Hessian-free optimization method for deep network and develop its distributed

variant which can utilize computing cluster to train large models. Furthermore,

we propose new algorithm to explore negative curvature direction by solving the

subproblem with BICGSTAB method involving possible indefinite true batch

Hessian information. We show that these techniques accelerate the training

process of deep neural network and sharing considerable speed-up by increasing

number of nodes.

Recovery Problem

Helder Inacio, Sabre Holdings Inc, 3150 Sabre Drive, Southlake,

TX, 76092, United States,

Helder.Inacio@Sabre.com

, Chunhua

Gao, Ramakrishna Thiruveedhi

Airline Crew Recovery can greatly reduce impact caused by disruptions by

assigning new rosters to crew. We compare different approaches that can be used

to solve this problem. The first approach is optimization based and is focused on

reducing overall cost by exploring all recovery options. Other heuristic

approaches focus on obtaining fast solutions but have limited search space. We

analyze the quality of solutions obtained by using different strategies. We

compare the benefits and drawbacks of using these in real-time recovery. The

comparisons are made on realistic scenarios of varying size and type of disruption.

WD78

Legends F- Omni

Opt, Metaheuristics

Contributed Session

Chair: Hasmukh Gajjar, Associate Professor, Indian Institute of

Management Indore, Rau-Pithampur Road, C#208, Prabandh Shikhar,

Indore - Madhya Pradesh, 453331, India,

hasmukh@iimidr.ac.in

1 - Building And Exploring Multiple Time-to-target Plots (m-tttplots)

To Compare Randomized Algorithms

Celso C Ribeiro, Full Professor, Universidade Federal Fluminense,

Rio de Janeiro, Brazil,

celso.ribeiro@gmail.com,

Alberto Reyes

Time-to-target plots (tttplots) for each problem instance are a useful tool to

characterize, evaluate, and compare the behavior of randomized heuristics for

combinatorial optimization problems. Multiple time-to-target plots (m-tttplots)

are their natural extension to sets of multiple instances. We show how to build an

m-tttplot from the individual tttplots for each instance in the set and we illustrate

several case studies to illustrate the applicability and usefulness of the newly

proposed m-tttplots tool.

2 - Guided Tabu Algorithm For Parallel Optimization

Hesam Shams, PhD Student, University of Tennessee, 851 Neyland

Drive, 525 John D Tickle Engineering Building, Knoxville, TN,

37996, United States,

hshams@vols.utk.edu,

Oleg Shylo

We consider a large class of optimization algorithms that explore solution space by

moving from one solution to another via some local neighborhood structure. To

enhance the performance of such techniques, we explore effective and scalable

methods for storing information about visited solutions to guide future search

steps. In particular, we investigate an extension of the tabu search methodology

by integrating a long term memory with tabu list dynamics. The proposed

algorithm and its parallel version was tested on well-established benchmark

instances of job shop scheduling and max-cut problems revealing excellent

computational performance.

3 - Heuristics For The Steiner Traveling Salesman Problem

Celso C Ribeiro, Universidade Federal Fluminense, Rio de Janeiro,

Brazil,

celso.ribeiro@gmail.com

, Ruben Interian

Given a weighted undirected graph and a set of required vertices, the Steiner

traveling salesman problem seeks a minimum weighted closed walk on the graph

that visits all required vertices. Since a walk is sought, some vertices may be

visited more than once. Similarly, some edges may be traversed more than once.

We describe a set of benchmark instances and present numerical results obtained

with a GRASP heuristic developed for this problem.

4 - Statistical Bounds For Grasp Heuristics Of Np-hard Problems

Mengjie Han, PhD, Dalarna University, Högskolan Dalarna,

791 88 Falun, Sweden, Falun, 791 88, Sweden,

mea@du.se

,

Kenneth Carling

This work aims at providing statistical bounds for Greedy Randomized Adaptive

Search Procedures (GRASP) to NP-hard problems. The quality of the solution to

the NP-hard problems is always difficult to be evaluated due to the pre-set the

number of iterations. The studies of suggesting statistical bounds as evaluation

methods are rare. Thus, we propose the statistical estimator with confidence

intervals for GRASP heuristics where four classical NP-hard problems are tested.

We also suggest examining a new statistic SR for a stopping rule as a

complimentary criteria when probabilistic stopping rules are used.

5 - Optimal Shelf Space Allocation And Inventory Planning For Fresh

Produce In Retail Store

Hasmukh Gajjar, Associate Professor, Indian Institute of

Management Indore, Rau-Pithampur Road, C#208, Prabandh

Shikhar, Indore - Madhya Pradesh, 453331, India,

hasmukh@iimidr.ac.in

, Bhavin J. Shah

We consider the stock-dependent demand for fresh produce in a retail store. This

paper formulates a mathematical model for joint optimization of shelf space

allocation and inventory replenishment.

WD79

Legends G- Omni

Opt, Combinatorial II

Contributed Session

Chair: Prasanna Ramamoorthy, IIM Ahmedabad, Vastrapur,

Ahmedabad, 380015, India,

prasannar@iima.ac.in

1 - An Exact Algorithm For The Covering Capacitated Vehicle

Routing Problem

Christopher John Wishon, Arizona State University, Tempe, AZ,

United States,

cwishon@asu.edu

, J. Rene Villalobos

The Covering Capacitated VRP is similar to the traditional VRP except customers

can have their demand serviced by a vehicle stopping at a nearby location

assuming that the visited location is within the predetermined service radius of

the customer seeking service. This problem is applicable to many VRP applications

including the planning of emergency services and mobile retailers. An exact

solution method is presented based on the set covering formulation. A branch-

and-price methodology was employed and feasible covering routes were

generated as needed. The algorithm was tested on existing data sets with the

results demonstrating the technique was able to solve problems with up to 50

customers.

WD77

1 - Inexact Block Coordinate Descent Methods For Symmetric

2 - Generalized Sparse Precision Matrix Selection For Fitting

3 - Large Scale Distributed Hessian-free Optimization For Deep

4 - Comparing Different Approaches To Solve Airline Crew