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Gutierrez-Wing E.S.,National Research Center sarrollo Tecnologico | Aguirre-Romano J.E.,Electric Research Institute of Mexico
Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference 2009, DETC2009 | Year: 2010

This article presents a closed-form solution to the computation of unbalance correction masses for rigid rotors mounted on flexible bearings. The solution requires measurements of the response of the rotor-bearing system to the unbalance that is to be corrected, as well as knowledge of its total mass or other stiffness or damping parameters that are readily deducible from the mounting configuration. No detailed mathematical models or information from previous balancing runs are required. The computation is based on the relationships that exist between some spatial and modal parameters of rotor-bearing systems. Such relationships are derived in this article, and their use in the computation of balancing masses is presented and verified with results from an experimental test rig. This work demonstrates the feasibility of balancing rigid rotors without trial runs, detailed models or historical balancing records. Copyright © 2009 by ASME. Source

Vazquez A. G.,National Polytechnic Institute of Mexico | Perez O. J.,National Research Center sarrollo Tecnologico
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

One of the challenges of applications of distributed database (DDB) systems is the possibility of expanding through the use of the Internet, so widespread nowadays. One of the most difficult problems in DDB systems deployment is distribution design. Additionally, existing models for optimizing the data distribution design have only aimed at optimizing query transmission and processing costs overlooking the delays incurred by query transmission and processing times, which is a major concern for Internet-based systems. In this paper a mathematical programming model is presented, which describes the behavior of a DDB with vertical fragmentation and permits to optimize its design taking into account the nonlinear nature of roundtrip response time (query transmission delay, query processing delay, and response transmission delay). This model was solved using two metaheuristics: the threshold accepting algorithm (a variant of simulated annealing) and tabu search, and comparative experiments were conducted with these algorithms in order to assess their effectiveness for solving this problem. © 2010 Springer-Verlag. Source

Lopez-Estrada F.R.,Instituto Tecnologico de Tuxtla Gutierrez | Gonzales J.H.C.,Instituto Tecnologico de Tuxtla Gutierrez | Ponsart J.C.,University of Lorraine | Ponsart J.C.,French National Center for Scientific Research | And 3 more authors.
IFAC-PapersOnLine | Year: 2015

This work is dedicated to the design of a robust fault detection system for an anaerobic bioreactor modeled as a Descriptor Linear Parameter Varying system (D-LPV) system with unmeasurable gain scheduling functionss. The main goals are: first, an accurate D-LPV representation of the nonlinear model is obtained by considering the sector nonlinearity modeling approach. Second, a LPV observer is designed to estimate the bioprocess states variables. The observer considers the gains scheduling functions depending on estimated states due to the lack of a biomass mass sensor. Third, in oder to perform fault detection and isolation, by mean of residual generation, a bank of observers is designed. For each observer, sufficient conditions to guarantee asymptotic stability and robustness against disturbance are given by a set of feasible Linear Matrix Inequalities (LMIs). Finally, some simulations in fault-free and faulty operations are considered on the bioreactor system. © 2015 IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. Source

Pazos R. R.A.,Institute Tecnologico Of Cd Madero | Rojas P. J.C.,National Research Center sarrollo Tecnologico | Santaolaya S. R.,National Research Center sarrollo Tecnologico | Martinez F. J.A.,Institute Tecnologico Of Cd Madero | Gonzalez B. J.J.,Institute Tecnologico Of Cd Madero
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

A query written in natural language (NL) may involve several linguistic problems that cause a query not being interpreted or translated correctly into SQL. One of these problems is implicit information or semantic ellipsis, which can be understood as the omission of important words in the wording of a query written in NL. An exhaustive survey on NLIDB works has revealed that most of these works has not systematically dealt with semantic ellipsis. In experiments conducted on commercial NLIDBs, very poor results have been obtained (7% to 16.9%) when dealing with query corpora that involve semantic ellipsis. In this paper we propose a dialogue manager (DM) for a NLIDB for solving semantic ellipsis problems. The operation of this DM is based on a typification of elliptical problems found in queries, which permits to systematically deal with this problem. Additionally, the typification has two important characteristics: domain independence, which permits the typification to be applied to queries of different databases, and generality, which means that it holds for different languages such as English, French, Italian, Spanish, etc. These characteristics are inherited to the dialogue processes implemented in the DM, since they are based on this typification. In experiments conducted with this DM and a NLIDB on a corpus of elliptical queries, an increase of correctly answered queries of 30-35% was attained. © 2010 Springer-Verlag. Source

Morales E.,National Research Center sarrollo Tecnologico | Franch X.,Polytechnic University of Catalonia | Martinez A.,National Research Center sarrollo Tecnologico | Estrada H.,National Research Center sarrollo Tecnologico | Pastor O.,Polytechnic University of Valencia
CEUR Workshop Proceedings | Year: 2011

In current business practice an integrated approach to represent at the design level the technological infrastructure that gives support to business pro- cesses is needed. We argue that it is highly complex considering technology in terms of specific functionalities from the beginning because these functionali- ties depend on new business requirements produced continually by internal and external changes. However, business-technology integration has been largely neglected in the modeling of business processes, including i; models, consider- ing the technological components as highly abstract entities that do not require further description. In this paper, an overview of our approach to deal with technology representation in i; business process models is presented, which fo- cuses on the identification of quality attributes that are offered by specific tech- nologies and the representation of these technologies using a particular class of i; module. This approach has been explored in a previous work developing an example of a library in which an automatic identification technology is required to support some specific business processes. Source

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