Transcript Depto. Investigación Operativa, Computer Science Institute, Engineer Faculty Universidad de la República,

Depto. Investigación Operativa,
Computer Science Institute,
Engineer Faculty
Universidad de la República,
Uruguay
March 2005
Staff of the group
• Professors
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Héctor Cancela
María E. Urquhart
Omar Viera
Carlos Testuri
Franco Robledo
Graciela Ferreira
Daniel Meerhoff
Assistants
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Celina Gutiérrez
Antonio Mauttone
Alfredo Olivera
Martín González
Pablo Rodríguez Bocca
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Eight PhD and MsC students
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Students working on their
degree dissertations.
Courses
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Introduction to Operation Research.
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Extensions to Linear Programming and Integer
Programming.
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Metaheuristics solving Combinatorials Problems.
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Optimization under uncertainty.
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Discrete Event Simulation.
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E-commerce and OR.
Main research areas and
methodologies
Main application areas
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Transportation,
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Logistics,
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Communications.
Methodologies
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Heuristics, meta-heuristics.
Mathematical programming,
in particular
stochastic programming and
dynamic programming.
Cooperation areas
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High performance
Computing.
Other areas of interest
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Finance,
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Electricity networks,
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Re-engineering.
Optimization
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Simulation
Discrete event simulation.
Monte Carlo methods,
Variance Reduction methods.
Transportation
Vehicle routing
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“Cluster first, route second" methods (Omar Viera,
Libertad Tansini, Daniel Giosa, Marita Urquhart)
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Routing heuristics.
- Assignment heuristics, Genetic Algorithms.
Metaheuristics
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Ant Systems (Hector Cancela, Omar Viera).
Adaptive memories (Alfredo Olivera, Omar Viera).
Article
“Adaptative Memory Programming for the Vehicle
Routing Problem With Multiple Trips”.
A. Olivera, O. Viera (2005)
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Difficulty: each vehicle may perform several routes in
the same planning period, it implies the design of a set
of routes and the assignmentnt of those routes to the
available vehicles.
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Heuristic based on AMP (Rochat and Taillard).
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Tested over the 104 benchmark problems proposed by
Taillard et.al.
Transportation
Urban public transport (H.Cancela, M.E. Urquhart, A.
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Mauttone. O. Viera)
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Bus line simulation.
Origin-destination-time demand matrix estimation.
Bus line design.
Intelligent Transport Systems.
Vertical transport (H. Cancela, O. Viera)
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Capacity estimation.
Simulation and comparison of scheduling algorithms.
Extended Abstract and Posters
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“Bus lines design in urban public transport”
A.Mauttone, M.E. Urquhart (ICIL Poster-2005).
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“GRASP multiobjetivo para el diseño de rutas y frecuencias
en transporte colectivo público” (CLAIO 2004)
This work is about the design of bus lines (routes and frequencies) in urban public
transport systems. It is part of a long reach project, whose objective is to
develop a tool that supports the transit network design planning in a strategic
context.
Characteristics
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High combinatorial complexity.
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Multi-objective nature: objectives of users and operators expressed in
different units, and usually contradictory (an improvement in one objective
implies a detriment in the other one).
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Mixed variables: discrete variables represent the sequences of nodes in each
bus route, and continuous variables represent the bus frequencies.
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Real Case study with real data
Communication networks
Wide Area Network topology design (H.
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Cancela).
Steiner trees, 2-connected networks,
Generalized Steiner problems in graphs:
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Ant Systems
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GRASP (F. Robledo)
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Genetic Algorithms
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Other heuristics.
Topology design with uncertain demands
(stochastic programming) (C. Testuri).
Networks
Reliability models (H.Cancela)
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Classical models: evaluation using variance reduction
techniques. ( and G. Rubino)
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Models with distance restrictions. (and L. Petingi)
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Optimization - GRASP, Genetic Algorithms.
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Peer-to-peer network models.
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Performance evaluation of computer clusters
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Petri networks.
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Markov chains, simulation.
Article
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“Network design with node connectivity constraints”
H. Cancela, F. Robledo, G. Rubino.(2004)
Problem: to find the least costnetwork topology that
satisfies some node-disjoint path connection
requirements;
Modeled as a GSPNC (Generalized Steiner Problem
with Node-Connectivity Constraints);
Solved with an algorithm based on GRASP.
Present experimental results, test problems with more
than 100 nodes, obtained from public libraries.
Article
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“A GRASP algorithm with RNN based local search
for designing a WAN acces network” H. Cancela, F.
Robledo, G. Rubino.(2004)
Problem: to design the access network topology of a
Wide Area Network;
Modeled as a variant of the Steiner Problem in graphs.
Solved with an algorithm based on GRASP that employs
Random Neural Networks as local search heuristic.
Present experimental results, test problems obtained
from the SteinLib .
Article
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“Evolutionary algorithms applied to reliable
communication network design”
S. Nesmachnow, H. Cancela, E. Alba.(2004)
Problem: to design a reliable communication network
topology;
Modeled as a Generalized Steiner Problem in graphs (to
design a minimum cost subnetwork verifying a set of prefixed minimum
connection requirements for pairs of terminal nodes).
Solved with a set of pure and hybrids Evolutionary
algorithms (GA, CHC, GA+SA, Parallel)
Present a comparative study of them with a random test
suite of three .
Technical reports
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“Diseño de redes de Comunicaciones con
Incertidumbre en la demanda” Degree dissertation.
J. Viera, C. Testuri.(2004)
Multicommodity network, Sotchastic Programming.
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“Motor de metaheurísticas para el problema de
asignación de salones de la Facultad de Ingeniería”
S. Costabel, M. Urquhart (2005). Master thesis.
Timetable problem, Tabu-Search, Genetic Algorithm,
Ant-systems. Real test-case: Engineering Faculty.
Simulation, other topics
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Discrete event simulation (H.Cancela.
M.Urquhart).
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Scheduler for DES.
L.Murray
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Bus line design.
A. Mauttone et.al
Projects with industry and public
sector
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CoNaProLe: truck routing for milk collection.
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IMM, IMR: urban public transport studies.
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ANCAP / DUCSA: preliminary study of
opportunity areas for optimization.
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MGAP: study of organization of computing
center.
BPS: third party services..
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International cooperation
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INRIA (Institut National de Recherche en Informatique)
Rennes, Francia: Team “Planning of Architecture and
Infrastructre of Networks” , joint projects, students codirection. (Communication Networks design)
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City University of New York: joint projects.(Networks
design –diameter restriction)
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PROSUL network “Discrete optimzation and graphs:
theory, algorithms and applications”: USP, UFRJ, U.
Chile, UBA, U. Rosario, etc.
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ALFA network “Solving real problems of high
complexity in combinatorial optimization”: U. Bologna,
Avignon, L. de Bruselas, U. Concepción, etc. Students
co-direction.
Events organized
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IV and X ELAVIO (Escuela Latinoamericana de
Verano de Investigación Operativa): Montevideo 1997,
2004.
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ICIL 2005 (International Conference on Industrial
Logistics): Montevideo, february 2005.
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CLAIO 2006 (Congreso Latino Ibero Americano de
Investigación de Operaciones): Montevideo, november
2006.