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INFORMS Philadelphia – 2015

125

3 - Evacuation Modeling and Betweenness Centrality

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

Disaster management and evacuation modeling are vital for the welfare of

modern urban societies. However, it is true that evacuating large urban areas is a

very difficult problem due to the large scale of operations and the dynamic nature

of most hazard phenomena. In this talk, we present two novel islanding

techniques with the goal of decomposing large-scale network problems to smaller

ones of manageable size. Computational results are also presented to show the

success of our methodologies.

4 - Variable Versus Fixed Congestion Pricing under Day-to-Day

Traffic Dynamics

Zhengtian Xu, University of Florida, 511 Weil Hall, Gainesville,

FL, 32611, United States of America,

zhengtianxu@ufl.edu

,

Yafeng Yin

This paper compares the effectiveness of fixed and variable congestion pricing on

evolving network flows to a target flow distribution under day-to-day traffic

dynamics. Fixed pricing charges constant tolls while variable pricing updates tolls

every day based on recent days’ traffic conditions. The paper proves that the latter

does not necessarily perform better than the former and provides conditions

when this situation arises. Numerical experiments are presented to demonstrate

the comparison.

5 - Vulnerability Modeling and Analysis of Complementary

Transportation Systems

Liu Hong, Associate Professor, Huazhong University of Science

and Technology, Room W.308, South 1,1037#, Luoyu Road,,

Wuhan, China,

liu.hong.science@gmail.com

, Min Ouyang,

Xiaozheng He

This paper proposes a network-based approach to model and analyze the

vulnerability of complementary transportation systems, with main focus on

quantifying their complementary strength, assessing dynamic vulnerability and

discussing critical components. Two level complementary systems are used to

illustrate the tractability and effectiveness of the proposed method, including

railway and airline system in China (national level), metro and bus system in

Wuhan city in China (Urban level).

SD18

18-Franklin 8, Marriott

Theory and Applications of Coordinate Descent and

Alternating Direction Methods

Cluster: Modeling and Methodologies in Big Data

Invited Session

Chair: Brendan Ames, Assistant Professor, University of Alabama,

Department of Mathematics, Box 870350, Tuscaloosa, AL, 35487,

United States of America,

bpames@ua.edu

1 - Block Coordinate Stochastic Gradient Method

Yangyang Xu, University of Minnesota, Institute of Math and

Application, Minneapolis, MN, United States of America,

xuyang.gucas@gmail.com

, Wotao Yin

Stochastic gradient (SG) can quickly solve a problem with many components in

the objective to a moderate accuracy, and block coordinate descent (BCD) method

can quickly solve problems with multiple (blocks of) variables. In this talk, we

will introduce a block stochastic gradient (BSG) method that combines SG and

BCD for problems with many components in the objective and with multiple

blocks of variables. We will show its convergence and demonstrate its superiority

over SG and BCD.

2 - Proximal Methods for Sparse Discriminant Analysis

Brendan Ames, Assistant Professor, University of Alabama,

Department of Mathematics, Box 870350, Tuscaloosa, AL, 35487,

United States of America,

bpames@ua.edu

We consider the problem of simultaneously performing classification and feature

selection in the high-dimension, low sample size setting, where the number of

features of our data is large while the number of samples is limited. In particular,

we propose an alternating direction method for performing optimal scoring-based

linear discriminant analysis with a sparseness criterion, where proximal gradient

methods are used to update the decision variables in the alternating direction

framework.

3 - Iteration Complexity Analysis of Block Coordinate

Descent Methods

Mingyi Hong, Iowa State University, 3015 Black Engineering,

Ames, IA, 50011, United States of America,

mingyi@iastate.edu

We provide a unified iteration complexity analysis for a family of block coordinate

descent methods. We unify these algorithms under the so-called Block Successive

Upper-bound Minimization framework, and show that they achieve a global

sublinear iteration complexity. Moreover, for the case of block coordinate

minimization where each block is minimized exactly, we establish the sublinear

convergence rate of O(1/r) without per block strong convexity assumption.

4 - Self Equivalence of the Alternating Direction Method of Multipliers

Ming Yan, Assistant Professor, Michigan State University,

220 Trowbridge Rd, East Lansing, MI, 48824, United States of

America,

yanm@math.ucla.edu

In this talk, we show that ADM applied to a primal formulation is equivalent to

ADM applied to its Lagrange dual; ADM is equivalent to a primal-dual algorithm

applied to the saddle-point formulation of the same problem. In addition, when

one of the two objective functions is quadratic, we show that swapping the

update order of the two primal variables in ADM gives the same algorithm.

SD19

19-Franklin 9, Marriott

Computational Data Analytics

Sponsor: Computing Society

Sponsored Session

Chair: Dorit Hochbaum, University of California, IEOR, “Etcheverry

Hall, Berkeley, Ca, 94720, United States of America,

dhochbaum@berkeley.edu

1 - Improved Algorithms Solving Generalizations of Isotonic

Median Regression

Cheng Lyu, University of California, 4141 Etcheverry Hall,

Berkeley, CA, 94720, United States of America,

chenglu@berkeley.edu

, Dorit Hochbaum

Isotonic median regression (IMR) problem is a well-known statistical

nonparametric regression problem. We address here generalizations of IMR for

which we devise efficient algorithms. Our algorithms improve on the best

previously known complexity for the special case of IMR. Some applications of

independent interest of the generalized problems include total variation on a

path, signal processing, and nearly-isotonic regression.

2 - Big Data Aggregation and Truncation by

Pseudo-boolean Polynomials

Boris Goldengorin, C. Paul Stocker Visiting Professor, Ohio

University, 283 Stocker Center, Athens, OH, United States of

America,

goldengorin@gmail.com

In this talk we show how to aggregate and truncate the numerical data in huge m

(rows) times n (columns) tables by means of ordering the entries within their

columns in a non-decreasing (non-increasing) order. The ordered columns can be

represented by the corresponding permutations and differences between the

neighboring entries. Our computational study shows that for complete networks

containing thousands of vertices we are able to reduce the number of entries by

more than 90%.

3 - Adjacency-clustering for Yield Prediction in Integrated

Circuit Manufacturing (ICM)

Dorit Hochbaum, University of California, IEOR, Etcheverry Hall,

Berkeley, CA, 94720, United States of America,

dhochbaum@berkeley.edu

, Sheng Liu

Accurate yield prediction in ICM enables early detection of processing problems.

It is noted that defects tend to be clustered and a circuit likely to be defective if its

neighbors are defective. This Neighborhood Effect NE is not captured in

traditional spatial modeling approaches. We model the yield prediction problem

with NE as a Markov Random Field model (MRF). A comparison with leading

approaches (GLM and GLMM) demonstrates that MRF provides superior accuracy

and time complexity.

SD19