Seminar schedule: Year 2013
- Thursday, November 21st 2013, Time: 12:30
Ivan Contreras. Mechanical and Industrial Engineering Dept., Concordia University and CIRRELT. Montreal, Canada.
- Friday, October 25th 2013, Time: 12:30
Claudia Archetti, Università degli Studi di Brescia, Itàlia
- Monday, October 7th 2013, Time: 12:30
Samuel D. Oman, Department of Statistics, Hebrew University, Jerusalem, Israel
- Friday, October 4th, 2013, Time: 12:30
Roger Z. Ríos, Universidad Autónoma de Nuevo León, México
- Friday 8th of march 2013, Time 18:00-19:30
Presenters: Jan Graffelman (Seminar DEIO) and Lupe Gómez (SCE)
Chairman: Erik Cobo
Program:
1. Speaker 1: Time to change disclosing clinical trials. Rosa Lamarca, Clinical Statistics, Laboratoris Almirall, Barcelona
2. Speaker 2: Bad JAMA? Are medical journal editors biased in favour of positive studies? Stephen Senn, Competence Center in Methodology and Statistics, Luxembourg.
3. Discussion
4. Surprise
- Wednesday Feb, 20, 2013, Time:12:30
Jose Herskovits Norman,OptimizE - Engineering Optimization Lab, Mechanical Engineering Program, COPPE
Federal University of Rio de Janeiro
- Tuesday, Jan, 22, 2013, Time 10:30
Marcos J. Rider, Electrical Engineering Department, Universidade Estadual Paulista, Brasil.
The Minimum Flow Cost Hamiltonian Cycle Problem: Formulations and Related Problems
SPEAKER: Ivan Contreras
LANGUAGE: Spanish
PLACE: C5 Building, Room C5016,Campus Nord, UPC (see map)
DATE: Thursday, November the 21st 2013. Time: 12:30
ABSTRACT:
In this talk we introduce the Minimum Flow Cost Hamiltonian Cycle Problem (FCHC). Given a graph and positive flow between pairs of vertices, the FCHC consists of finding a Hamiltonian cycle that minimizes the total flow cost between pairs of vertices through the shortest path on the cycle. Potential applications of the FCHC arise naturally in telecommunications network design and in rapid transit systems planning, namely in the design of automated guided vehicles (AGV) networks. This problem also appears as a subproblem in complex general network design problems in which a ring topology is sought. We present five different mixed integer programming formulations for the FCHC which are theoretically and computationally compared. We also propose several families of valid inequalities for one of the formulations and perform some computational experiments to assess the performance of these inequalities.
THE SPEAKER:
Ivan Contreras is an Assistant Professor at Concordia University in the Department of Mechanical and Industrial Engineering, and is a regular member of the Interuniversity Research Centre on Enterprise Networks, Logistics and Transportation (CIRRELT). He obtained his B.Sc. and M.Sc. in Industrial Engineering from the University of Americas, Mexico. In 2009 he received his Ph.D. degree from the Department of Statistics and Operations Research at the Technical University of Catalonia. His research areas of expertise are hub location and hub network design, discrete facility location, network design, and decomposition methods for large-scale optimization.
Further information on Ivan Contreras and his research can be found at his webpage.
Top
Matheuristics for arc routing problems with profits
SPEAKER: Claudia Archetti
LANGUAGE: EnglishPLACE: C5 Building, Room C5016, Campus Nord, UPC (see map)
DATE: Friday, October the 25th 2013. Time: 12:30
ABSTRACT:
Matheuristics are heuristic solution methods that make use of mathematical programming models in a heuristic framework. The interest in this solution methodology has remarkably increased in the last ten years. They have been applied successfully to many application domains, proving to be competitive with respect to more classical heuristic or metaheuristic schemes.
Among the main application domains, we find the class of routing problems. Matheuristics have been applied to several different routing problems and include a number of different approaches.
We focus on the application of matheuristics to arc routing problems with profits which is a quite recent and challenging class of problems where customers are associated with a profit and the carrier has to determine the most convenient subset of customers to serve. We will present two applications dealing with a single vehicle case and a multiple vehicles case.
THE SPEAKER:
Claudia Archetti is Assistant Professor in Operations Research at the University of Brescia where she is staying since 2005. She teaches courses for undergraduate, master and PhD students in OR and logistics. The main areas of the scientific activity are: models and algorithms for vehicle routing problems; mixed integer mathematical programming models for the minimization of the sum of inventory and transportation costs in logistic networks; exact and heuristic algorithms for supply-chain management; reoptimization of combinatorial optimization problems.
She has carried out the scientific activity in collaboration with Italian and foreign colleagues and published joint papers with some of the best researchers at the international level.
She is author of more than 35 publications in international journals. She is Associate Editor of Networks.
Further informacion about Claudia can be found here
Top
Methods for Descriptive Factor Analysis of Multivariate Geostatistical Data: a Case-study Comparison
SPEAKER: Samuel D. Oman
LANGUAGE: EnglishPLACE: C5 Building, Room C5016, Campus Nord, UPC (see map)
DATE: Monday, October the 7th 2013. Time: 12:30
ABSTRACT: We consider the framework in which vectors of variables are observed at different points in a region. Such data are typically characterized by point-wise correlations among the variables, as well as spatial autocorrelation and cross-correlation. To help understand and model this dependence structure, one may define factors which operate at different spatial scales. We consider four such factor-analytic techniques: the Linear Model of Coregionalization and three recently proposed alternatives. We apply them to the same set of data, concentrations of major ions in water samples taken from springs in a carbonate mountain aquifer. The methods give quite different results for the spring chemistry, with those of the Linear Model of Coregionalization being much more interpretable. We suggest some possible explanations for this, which may be relevant in other applications as well.
KEY WORDS: Carbonate dissolution; Linear model of Coregionalization; Major ions; Principal component analysis; Sea water; Spatial correlation; Springs.
Top
A Novel Location-Allocation-Local Search Algorithm for Handling Connectivity and Multiple Balancing Constraints in Territory Design Systems
SPEAKER: Roger Z. Ríos
LANGUAGE: Spanish
PLACE: C5 Building, Room C5016, Campus Nord, UPC (see map)
DATE: Friday October the 4th, 2013. Time: 12:30
ABSTRACT:
Territory design is the problem of grouping small geographic areas called basic areas (e.g., counties, zip code areas) into larger geographic clusters called territories such that the latter fulfill relevant planning criteria. These criteria can either be economically motivated (e.g., average sales potentials, workload, number of customers) or have a demographic background (e.g., number of inhabitants, voting population). Moreover, spatial restrictions, like compactness or contiguity, are often demanded. Territory design problems are motivated by very different applications, ranging from political districting over the design of territories for waste collection to sales and service territory design.
In particular, in this talk a commercial territory design problem motivated by a real-world application from a bottled beverage distribution firm is presented. The problem consists of finding a set of territories subject to contiguity, compactness, and multiple balance requirements with respect to each node activity measure. After presenting a description of the problem and a discussion of its associated model, a proposed solution approach based on a novel location-allocation scheme that successfully handles the connectivity and multiple balancing constraints is described in detail. The talk will include an evaluation of the proposed method and its components in a variety of data instances showing its excellent performance
THE SPEAKER:
Roger Ríos is an Associate Professor of Operations Research in the Graduate Program in Systems Engineering at Universidad Autonoma de Nuevo Leon, Mexico. He has held Visiting Scholar positions at the Graduate Program in Operations Research (U. of Texas at Austin, USA), Department of Operations Research (Universitat Politècnica de Catalunya, Spain), Leeds School of Business (U. of Colorado), and High Performance Computing Center (U. of Houston). His research interests are mainly in designing and developing efficient solution methods to hard optimization problems. In particular, during the past few years he has addressed applied problems on territory design, forestry management, optimization of natural gas transportation systems, and scheduling in manufacturing systems. His research has been published in leading journals in the field. He is a member of the Mexican Academy of Sciences, and the Mexican System of Research Scientists. More about his work can be found here.
Top
Time to change disclosing clinical trials
SPEAKER: Rosa Lamarca
LANGUAGE: English
PLACE: FME, Edifici U, Aula: Sala d'Actes, Campus Sud, UPC, Pau Gargallo, 5, 02028 Barcelona
DATE: Friday 8th of March, 2013. Time: 18:00
ABSTRACT: Multiple efforts have been made in the publishing field to avoid fraud and disseminate relevant information to allow the scientific community to progress. Transparency in the publishing process started with the guidelines on authorship contribution in the early eighties by the International Committee of Medical Journal Editors and the suggestion of creating an international registry of clinical trials by Simes RJ. In the clinical trials setting, an increasing demanding environment exists towards transparency with the obligation to publish all the clinical trials, except Phase I, into clintrials.gov within 21 days after first patient first visit, and once the compound is approved by the FDA, results from subsequent trials must be published within one year of last patient last visit and 30 days after the approval for previous unpublished trials. Also, there is an EU clinical trials registry (Eudract & EU-CTR), and the EU guideline on clinical trial data and transparency is expected to be released for consultation in 2013. More recently, Alltrials campaign is pursuing the disclosure of all the Clinical Study Reports with BMJ announcing that clinical trials will be published only if the company is committed to "make the relevant anonymised patient level data available on a reasonable request", and GSK further stated that they will give access to detailed anonymised patient level data after their previous issue with paroxetine.
THE SPEAKER: Rosa Lamarca holds a PhD in Health Life Sciences of the Pompeu Fabra university (UPF). She graduated in Statistics at the Polytechnic University of Catalonia, and obtained a Master of Science in Applied Statistics at the Sheffield Hallam University. She is currently head of Clinical Statistics at Almirall in Barcelona. She worked as an investigator in the Health Services Research Unit at the "Institut Municipal d'Investigació Mèdica" in Barcelona from 1995 till 2001. She was professor of the master program in Public Health at UPF during 7 years, and associate professor of ESADE's MBA program during 3 years. She has published several articles in specialized journals and was Spanish delegate at the European Federation of Statisticians in the Pharmaceutical Industry from 2003 till 2005.
Top
Bad JAMA?
SPEAKER: Stephen Senn
LANGUAGE: English
PLACE: FME, Edifici U, Aula: Sala d'Actes, Campus Sud, UPC, Pau Gargallo, 5, 02028 Barcelona
DATE: Friday, 8th of March 2013. Time: 18:00
ABSTRACT: "But to be kind, for the sake of completeness, and because industry and researchers are so keen to pass the blame on to academic journals, we can see if the claim is true... Here again the journals seem blameless: 745 manuscripts submitted to the Journal of the American Medical Association (JAMA) were followed up, and there was no difference in acceptance for significant and non-significant findings." Bad Pharma, p34.
A central argument in Ben Goldacre's recent book Bad Pharma is that although trials with negative results are less likely to be published than trials with positive results, the medical journals are blameless: they are just as likely to publish either. I show, however, that this is based on a misreading of the literature and would rely, for its truth, on an assumption that is not only implausible but known to be false, namely that authors are just as likely to submit negative as positive studies. I show that a completely different approach to analysing the data has be used: one which compares accepted papers in terms of quality. When this is done, what studies have been performed, do, in fact, show that there is a bias against negative studies. This explains the apparent inconsistency in results between observational and experimental studies of publication bias.
THE SPEAKER: Stephen Senn is researcher at the Competences Center for Methodology and Statistics in Luxembourg. He has extensive experience in both academia and industry. As a former Professor of Statistics at the University of Glasgow, former Professor of Pharmaceutical and Health Statistics at University College London, statistician with the National Health Service in England and within the Swiss pharmaceutical industry, he is recognized worldwide for his studies in statistical methodology applied to drug development. He has been the recipient of national and international awards, including the 1st George C Challis award for Biostatistics at the University of Florida, and the Bradford Hill Medal of the Royal Statistical Society. He is the author of the monographs Cross-over Trials in Clinical Research (1993, 2002), Statistical Issues in Drug Development (1997, 2007) and Dicing with Death (2003), as well as numerous scientific articles published in internationally recognized, peer-reviewed journals. Professor Senn is a Fellow of the Royal Society of Edinburgh and an honorary life member of Statisticians in the Pharmaceutical Industry (PSI) and the International Society for Clinical Biostatistics (ISCB) and has an honorary chair in statistics at University College London. For more information on his research click here.
Top
Large Scale Optimization with FAIPA, the Feasible Arc Interior Point Algorithm, for nolinear optimization
SPEAKER: J. Herskovits Norman
LANGUAGE: English
PLACE: Campus Nord, UPC (see map)
DATE: Wednesday February the 20th, 2013. Time: 12:03
ABSTRACT:
Numerical algorithms for real life engineering optimization must be strong and capable of solving very large problems with a small number of simulations and sensitivity analysis. In this talk we describe some numerical techniques to solve very large problems with the Feasible Arc Interior Point Algorithm (FAIPA) for nonlinear constrained optimization. These techniques include quasi-Newton formulations that avoid the storage of the approximation matrix. They also involve numerical algorithms to solve in an efficient manner the internal linear systems of FAIPA. Numerical results with large size test problems and with a structural optimization example shows that FAIPA is strong an efficient for large size optimization.
THE SPEAKER:
Prof. José Herskovits Norman works on the development of Numerical Methods for Optimization and their applications in Mechanical Engineering, mainly in Structural Optimization and Stress Analysis involving variational inequalities. He is the author of a general interior point technique for nonlinear constrained optimization and a series of iterative algorithms based on this technique. These methods are employed by engineers and researchers. He also developed several methods for Structural Optimization covering a wide set of problems concerning discrete structures, such as trusses, beams and plates and also shape optimization of shells and solids. Herskovits' interior point algorithms also proved to be also strong and efficient in stress analysis of solids in contact and nonlinear limit analysis.
Click here to access his personal web page
Top
A Bilevel Approach for Optimal Location and Contract Pricing of Distributed Generation in Radial Distribution Systems Using Mixed-Integer Linear Programming
SPEAKER: Marcos J. Rider
LANGUAGE: Spanish PLACE: C5 building, room C5016, Campus Nord, UPC (see map)
DATE: Tuesday, January the 22th, 2013. Time: 10:30
ABSTRACT:
In this work a novel approach for the optimal location and contract pricing of distributed generation is presented. Such an approach is designed for a market environment in which the distribution company can buy energy either from the wholesale energy market or from the distributed generation units within its network. In this scenario, the location and contract pricing of distributed generation is determined by the interaction between the distribution company and the owner of the
distributed generators. These agents have different objective functions.
The distribution company intends to minimize the payments incurred in meeting the expected demand, while the owner of the distributed generation intends to maximize the profits obtained from the energy sold to the distribution company. This two-agent relationship is modeled in a bi-level scheme: the upper-level optimization is for determining the allocation and
contract prices of the distributed generation units, while the lower-level optimization is for modeling the reaction of the distribution company. The bi-level programming problem is turned into an equivalent single-level mixed-integer linear optimization problem using duality properties, which is then solved using commercially available software. The results, using a 34-node test distribution system, show the robustness and efficiency of the proposed model compared with other existing models. As regards contract pricing, the proposed approach allowed to find better solutions than those reported in previous work.
THE SPEAKER:
Marcos J. Rider (S’97–M’06) received the B.Sc. (Hons.) and P.E. degrees from the National University of Engineering, Lima, Perú, in 1999 and 2000, respectively; the M.Sc. degree from the Federal University of Maranhão, Maranhão, Brazil, in 2002; and the Ph.D. degree from the University of Campinas, Brazil, in 2006, all in electrical engineering.
Currently he is a Professor in the Electrical Engineering Department at the Universidade Estadual Paulista, Ilha Solteira, Brazil. His areas of research are the development of methodologies for the optimization, planning and control of electrical power systems, and applications of artificial intelligence in power systems.
Click here for further information
Top
Share: