Search results for "OPTIMIZATION"

Approximation of Feasible Parameter Set in worst case identification of block-oriented nonlinear models

2003

Abstract The estimation of the Feasible Parameter Set for block-oriented nonlinear models in a worst case setting is considered. A bounding procedure is determined both for polytopic and ellipsoidie sets, consisting in the projection of the FPS ⊂ R MN of the extended parameter vector onto suitable M or N-dimensional subspaces and in the solution of convex optimization problems which provide the extreme points of the Parameter Uncertainties Intervals of the model parameteres. Bounds obtained are tighter then in the previous approaches.

Efficient evolutionary approach to approximate the Pareto-optimal set in multiobjective optimization, UPS-EMOA

2010

Solving real-life engineering problems requires often multiobjective, global, and efficient (in terms of objective function evaluations) treatment. In this study, we consider problems of this type by discussing some drawbacks of the current methods and then introduce a new population-based multiobjective optimization algorithm UPS-EMOA which produces a dense (not limited to the population size) approximation of the Pareto-optimal set in a computationally effective manner.

Scatter Search and Path-Relinking: Fundamentals, Advances, and Applications

2010

Scatter search is an evolutionary metaheuristic that explores solution spaces by evolving a set of reference points, operating on a small set of solutions while making only limited use of randomization. We give a comprehensive description of the elements and methods that make up its template, including the most recent elements incorporated in successful applications in both global and combinatorial optimization. Path-relinking is an intensification strategy to explore trajectories connecting elite solutions obtained by heuristic methods such as scatter search, tabu search, and GRASP. We describe its mechanics, implementation issues, randomization, the use of pools of high-quality solutions …

PARAMETER BOUNDED ESTIMATION FOR QUASISPECIES MODELS OF MOLECULAR EVOLUTION

2006

Abstract The Quasispecies models identification for Evolutionary Dynamics is considered in a worst-case deterministic setting. These models analyze the DNA and RNA evolution or describe the population dynamics of viruses and bacteria. In this paper we identify the Fitness and the Replication Probability parameters of a genetic sequences, subject to a set of stringent constraints to have physical meaning and to guarantee positiveness. The conditional central estimate and the Uncertainty Intervals are determined. The effectiveness of the proposed procedure has been illustrated by means of simulation experiments while tests on real data are under concern.

Seismic Network Evaluation through Simulation: an application to the Italian RSNC-INGV

2010

The global comfort criteria as a tool for the optimization of the safety, quality and efficiency in the railway tracks.

2012

From the results of some memories already introduced in the VI International Conference of "Stochastic Geometry, Convex Bodies, Empirical Measure & Applications To Mechanics And Engineering Of Train-Transport", it’s improved now a criteria, based on global comfort analyses , that allows to optimize the safety of the exercise, the quality and the economic efficiency into the available resources.

Content Based Indexing of Image and Video Databases by Global and Shape Features

1996

Indexing and retrieval methods based on the image content are required to effectively use information from the large repositories of digital images and videos currently available. Both global (colour, texture, motion, etc.) and local (object shape, etc.) features are needed to perform a reliable content based retrieval. We present a method for automatic extraction of global image features, like colour and motion parameters, and their use for data restriction in video database querying. Further retrieval is therefore accomplished, in a restricted set of images, by shape feature (skeleton, local symmetry moments, correlation, etc.) local search. The proposed indexing methodology has been deve…

Supertargeting-based hierarchic evaluation for setting paths in relaxation of retrofitted Heat Exchanger Networks

2010

The application of pinch analysis to the retrofit of existing heat exchanger networks is a complex task, which can be hardly standardised due to the large number of unquantifiable design considerations. Top-down and bottom-up approaches have been usually pursued, respectively oriented to relax a Maximum Energy Recovery (MER) configuration and to improve the existing network by removing network pinches. In this paper the bottom-up approach is critically examined, considering a well known case study represented by an aromatics plant; a MER design is also obtained and evaluated, to represent a target for process improvement. The final objective of researches in this sector is the identificatio…

Optimization of polygeneration plants and μ-grids for civil applications

2010

The problem of combined energy production and distribution of warm and cold fluids is very complex because it includes two possible configurations, the small single unit for individual buildings and the large plant integrated with district heating networks. Dealing with such a complex problem, involving a very large number of variables, requires efficient algorithms and resolution techniques. The present study illustrates a MILP approach to the optimization of synthesis, design and operation for CHCP-based μ-grids including thermal energy storages. The proposed approach develops a method for designing and optimizing district energy systems, starting with the information available for the di…

Analisi degli effetti delle opzioni tariffarie regionali sull'ottimizzazione di μ-grids energetiche alimentate da impianti poligenerativi

2011

L'ottimizzazione di sistemi energetici complessi per la produzione e la distribuzione di fluidi caldi e freddi per utenti civili è un problema molto complesso; due possibili configurazioni possono essere prese in considerazione, ovvero le piccole unità singole per singoli edifici ed i grandi impianti integrati con reti di teleriscaldamento. Affrontare un problema così complesso, che coinvolge un numero molto elevato di variabili, richiede algoritmi e tecniche di risoluzione efficienti. La ricerca svolta ha consentito di sviluppare nuovi metodi di mathematical programming, ed in particolare tecniche di Mixed Integer Linear Programming (MILP), per quanto concerne l’ottimizzazione di sistemi p…