Informs 2015

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INFORMS Philadelphia – 2015
358
TD37
37-Room 414, Marriott
Therapy and Treatment
Contributed Session
Chair: Animesh Garg, PhD Student, UC Berkeley, 4141 Etcheverry Hall,
Berkeley, CA, 94720-1777, United States of America,
1 - Assessment of a Novel Device for Elbow Rehabilitation in Humans
Aline Callegaro, Researcher, UFRGS, 99 Osvaldo Aranha Avenue,
5 Floor, Porto Alegre, RS, 90035190, Brazil, ,
Carlos Fernando Jung, Clarissa Brusco,
Marcelo Gava Pompermayer, Márcia Elisa Echeveste,
Carla Schwengber ten Caten
This study aimed to assess a novel device for elbow rehabilitation in humans. The
functional prototype assessment was based on data collection in two stages:
application of local muscle vibration; and its association with Continuous Passive
Motion. Two way ANOVA was used to analyse the main factors. An average
increase of the muscle electrical activation resulted in first stage. The main factors
(frequency, sex, and treatment) had significant effect, as well as a few
interactions.
2 - Minimizing Metastatic Risk in Radiotherapy
Fractionation Schedules
Hamidreza Badri, Graduate Student, University of Minnesota,
ISyE Departemnt, 111 Church Street S.E., Minneapolis, MN,
55455, United States of America,
Jagdish Ramakrishnan, Kevin Leder
The treatment of metastatic cancer remains an extremely challenging problem.
Here we consider the problem of developing fractionated irradiation schedules
that minimize production of metastatic cancer cells. We observe that the resulting
fractionation schedules are different than those that result from more standard
objectives such as minimization of final primary tumor volume. Delivering large
doses in small fractions is suggested even in cases when a/b value of the tumor is
large.
3 - Customized 3D Printed Implants with Internal Channels for
Intracavitary High Dose Rate Brachytherapy
Animesh Garg, PhD Student, UC Berkeley, 4141 Etcheverry Hall,
University of California, Berkeley, CA, 94720-1777,
United States of America, Jean Pouliot,
J. Adam M. Cunha, I-Chow Hsu, Alper Atamturk, Ken Goldberg
High-Dose Rate Brachytherapy is an internal radiation therapy frequently used
for cancer treatment. Radioactive sources are briefly placed proximal to tumors.
Current methods for intracavitary HDR-BT use generic templates which limits
dose distribution to a small set of linear channels. We propose the use of
algorithmically customized 3D Printed implants with curved internal channels
that fit cavities without tissue puncture and aim to improve dose distribution and
treatment quality.
4 - Surgery Sequencing and Scheduling in Multiple ORs with
PACU Constraints
Miao Bai, Lehigh University, 200 W Packer Ave, Bethlehem, PA,
18015, United States of America, ,
Gregory Tonkay, Robert Storer
We study a multiple-OR surgery sequencing and scheduling problem with PACU
constraints. To minimize the cost incurred by waiting, idleness, OR blocking and
overtime, a two-stage solution scheme is proposed. In the first stage, a time-
indexed integer program is formulated and solved by Lagrangian relaxation and
dynamic programming to determine surgery sequences. Given surgery sequences
in all ORs, scheduled times of patients are found in the second stage by a sample-
gradient-based algorithm.
TD38
38-Room 415, Marriott
Probability
Contributed Session
Chair: Gene Hahn, Associate Professor, Salisbury University,
1101 Camden Ave., Salisbury, MD, 21801, United States of America,
1 - Fluctuation Analysis and the Marked Poisson Process
Randy Robinson, Bemidji State University, Bemidji, MN,
United States of America,
This presentation studies the marked point process with position dependent
marking. The focus was on predicting the first passage time of the marked
random walk when exiting a given rectangular set and the value of the process
upon the exit. A new density function for the related processes has been
obtained: a product of a negative exponential and modified Bessel functions
2 - Moments of a Random Set
Kemal Gursoy, Rutgers University, 100 Rockafeller Road,
Department of MSIS, Piscataway, NJ, 08854,
United States of America,
Let X be a random subset of the n-dimensional Euclidean space. Then the
moments of the measure of X could be constructed by the Lebesgue integral of
the probability measure of every point in X, over the n-dimensional Euclidean
space.
3 - A New Representation for the Stationary Distribution of
Markov Chains
Patrick Buckingham, Clemson University, Mathematical Sciences,
Clemson, SC, United States of America, ,
Brian Fralix
We present a new representation for the stationary distribution of ergodic Markov
chains, as well as analogous representations for Laplace transforms of transition
functions associated with such chains. Applications to hysteretic queues and other
models will be discussed.
4 - Queueing Systems with Adaptive Service Rates
Raik Stolletz, University of Mannheim, Room SO 230,
Schloss Schneckenhof Ost, Mannheim, Germany,
Jannik Vogel
In many service systems, for example call centers, the service rate could be
considered as a time-dependent decision variable to improve and stabilize the
performance of a queueing system. We present an M(t)/M(t)/c queueing model
with adaptive service rates. The SBC-approach is used to approximate the time-
dependent behaviour of by stationary models. This results in non-linear
optimization problem. Numerical examples show the benefits of assuming the
service rate as a decision variable.
5 - Modeling with the Tilted Beta Distribution
Gene Hahn, Associate Professor, Salisbury University, 1101
Camden Ave., Salisbury, MD, 21801, United States of America,
The beta distribution has an important limitation for the modeling of bounded
data. Its density is either zero or infinite at the endpoints except for special cases.
This makes modeling certain kinds of data difficult. The tilted beta distribution can
be used to easily model this data. We adopt a Bayesian perspective and examine
its usage in modeling real-world data.
TD39
39-Room 100, CC
Product Brand Differentiation and Pricing Decisions
Cluster: Operations/Marketing Interface
Invited Session
Chair: Ruixia Shi, California State University, Fullerton, 800 N. State
College Blvd., Fullerton, CA, 92834, United States of America,
1 - New Product Pricing Strategy in the Social Media Era
Gou Qinglong, Associate Professor, University of Science &
Technology of China, No.96, JinZhai Road Baohe District, Hefei,
China, , Kumar Subodha, Xiuli He, Juzhi Zhang
With the popularity of various social media platforms, the impacts of the word of
mouth effect and the reference price effect on a consumer’s purchasing behavior
have been significantly amplified in the current era. We incorporate these two
effects into a two period pricing model to investigate whether and in which
condition should a firm utilize a skimming or a penetration price strategy. Our
results show how these two effects influence a firm’s pricing strategy when he
launches a new product.
2 - Competition and Coordination in Online Retailers and
Express Companies
Yihong Hu, Assistant Professor, Tongji University,
We consider an online market as Taobao with homogenous and heterogeneous
consumers sensitive to service quality. Retailers collect a separate product price
plus shipping fee from consumers. They treat shipping fee as a source of revenue
by asking a large discount of shipping fee from shippers. We use game-theoretic
framework to study the competition and coordination between retailers and
shippers under different scenarios. The study finds that retailers’ behavior
increases consumers’ benefit.
TD37