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January 2003 – July 2005 ·
Ph.D. Thesis: Static and Dynamic Approaches for solving the
Vehicle Routing Problem with Stochastic Demands (VRPSD). Providing a set-partitioning model for the
multiple vehicle routing problem with stochastic
demands (VRPSD) under the static (“here-and-now”) approach. The model incorporates a recourse not
studied previously in the literature where vehicles perform completions
and/or extra trips after route failures for every demand scenario. The model
compares favorably to the one with the simple recourse of sending vehicles to
the depot after failure. Developing and
comparing several rollout algorithms for dynamically routing vehicles serving
customers with stochastic demands. The goal is to minimize the expected
distance to travel to serve all customers’ demands. We provide a
dynamic solution appropriate for real-time routing and present an alternate
solution method to the static or “here-and-now” approach
traditionally used for solving the VRPSD. Related areas: Stochastic Programming, Dynamic Programming, and
Heuristic Optimization. Research advisor: Dr.
Robert Storer |
May 2002 – July 2002 ·
International Internship. Fraunhofer Institute of Material Flow
and Logistics at Developed and
compared an ant-colony and a greedy algorithm for sequencing traversing cars
in a warehouse. Coded algorithms in JAVA for integrating them to an open
source warehouse information system being developed
at the Institute. Related Areas:
Heuristic Optimization, Java Programming Co-author: Hubert Buechter, Dipl. Ing. |
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January 2003 - May 2003
Key concepts:
Modeling stochastic programs under the deterministic equivalent approach, the
value of the stochastic solution, multistage stochastic programs, two-stage
stochastic linear programs with fixed recourse, properties of the recourse
function, chance constraint programming, L-shaped method and stochastic
integer programming, bunching and other efficiencies. Final Project:
Computing a Lower Bound L on the recourse function Q(x) for the Integer
L-Shaped algorithm applied to the capacitated vehicle routing problem with
stochastic demands. |
August 2002 - December
2002
Key
concepts: Forward and backward programming. Approximate dynamic programming techniques and
deterministic continuous time optimal control. Final Project:
C++ implementation of a rollout policy for the single vehicle routing problem
with stochastic demands |
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January 2002 - May 2002
Key
concepts: Genetic algorithms, Tabu Search,
simulated annealing, ant-colony systems and other heuristics in combinatorial
optimization. Study of applications for vehicle routing, cutting stock and
scheduling problems. Projects:
Key concepts:
Problem Formulation, Polyhedral Theory, Branch and Bound methods, Cuts, and
Column Generation Project:
Implementing A branch and cut algorithm for the Multi-Knapsack problem
Key concepts:
UML, Object Oriented Programming, Applets, animation tools, cloning, JAVA API
1.4 documentation Project:
Implementing the breakout game using JAVA and UML |
August 2001 - December
2001
Key
concepts: Fixed and random effects, model adequacy checking, blocking,
factorial designs, confounding, fractional designs, nested designs, analysis
of covariance. Project
presentations:
Key concepts:
Auction and electronic markets, service network design Paper
presentation: Scheduling trains and containers with due dates and dynamic
arrivals. Candace
A. Yano, Alexandra M. Newman, Transportation Science, vol
35, No. 2, May 2001. Final project: An
Integer programming approach vs. a heuristic approach for scheduling trains
and containers with due dates and dynamic arrivals
Key concepts:
mixed investments, the fallacy of reinvestment rate assumptions, multiple
project selection models, serial and parallel replacement analysis, dynamic
programming approaches in replacement analysis Final project:
Real options to evaluate investment opportunities and replacement
alternatives |
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January 2001-May 2001
Key
concepts: convex analysis, duality theory, algorithms for solving non-linear
optimization problems using mathematical programs: Mathematica,
MATLAB.
Key
concepts: logistics planning: inventory, transportation and location
strategies, impact of logistics strategy in customer service. Key project
presentations:
Key concepts:
value of delayed differentiation, logistics network configuration,
quantifying the bullwhip effect, risk pooling, multi-echelon capacitated
inventory systems, vendor managed inventories, collaborative forecasting, Web
economy, supply chain contracting. Key project
presentations:
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August 2000-December 2000
Key concepts:
forecasting, multi-echelon inventories, aggregate production planning.
Key concepts:
HTML, PHP, MySQL, JavaScript Final
project presentation: Web application for students in queuing and simulation
courses. Students solve the
problem with different numerical scenarios, obtain grades, see the final
solution, and compare their performance vs. other students in the class. Topics related:
Sample size estimation, distribution fitting, costs estimation, HTML, JavaScript,
server side scripting with PHP, MySQL, Apache http server
Key
concepts: Network hardware and software, reference models and layers, ATM
networks. Final
project: Simulation of wireless networks and current issues about wireless
networks applications. Topics related: Blue Tooth technology, Wireless Application
Protocol (WAP), Ad-hoc networks, reactive protocols, network simulators, OPNET and IT Decision Guru network
simulation packages. |