Search results for " optimization."
showing 10 items of 2333 documents
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.
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…
Green Roofs’ End of Life: A Literature Review
2023
Green roofs are increasingly being used in urban settings because of the many benefits they are capable of providing. Because of their widespread use, the issue of how to conduct proper disposal of green roofs once they have reached their end of life is beginning to be raised. The present study is a review of the scientific literature published between 2007 and 2022. Specifically, the contribution of this review study is to clarify whether a waste scenario exists and if so, identify the methodological frameworks and/or criteria used in green roof-related studies to establish the end-of-life scenario of a given green roof, which will then be used to analyze its environmental and economic per…
An Experimental Comparison between an Ironless and a Traditional Permanent Magnet Linear Generator for Wave Energy Conversion
2022
Permanent Magnet Linear Generators (PMLGs) are currently being studied for sea wave energy harvesting. Typically, a PMLG consists of an iron-made armature and a moving translator. The permanent magnets adoption produces parasitic effects, such as cogging force, and the machine weight increment. A solution could be the adoption of an ironless configuration, accepting a power density reduction. This paper investigates the use of ironless PMLGs in sea wave energy conversion systems by an experimental comparative analysis between an iron PMLG prototype and an ironless PMLG prototype, which share the same geometry. The main electrical and mechanical parameters (resistance, mass, and magnetic fie…
Urban Energy Hubs Economic Optimization and Environmental Comparison in Italy and Vietnam
2018
This paper aims to perform the minimization of the yearly energy supply cost from the main electricity and natural gas grids related to an energy district, considering the installation of different equipments. The case study refers to energy consumption of a medium density urban district and involves the exploitation of different energy sources and devices (photovoltaic systems, electrical energy storage, heat pumps and cogenerators). The analysis of the district energy supply is accomplished through an energy hub model. After a cost analysis related to the considered energy systems, a MILP algorithm was used for the optimization of a cost function and the simulation of various scenarios. M…
DESIGN AND OPTIMIZATION OF A CHASSIS FOR A FORMULA SAE RACE CAR
2009
In this paper, the design process of a new chassis for a Formula SAE car is presented. The chassis is undoubtedly one of the most important parts of the car, both for the influence that it has on the vehicle dynamic behaviour, and because it is the main component that assures the driver safety. The new designed chassis is composed of many structural tubular bars and has been equipped with systems for the joining of all the auxiliary members. After the definition of the masses distribution and the choice of the main dimensions, preliminary CAD and FEM models have been carried out for the evaluation of the structural behaviour of this kind of vehicle. Successively, in order maximizing the tor…
Optimal Selection of Maintenance Actions on a Multi-Component System
2010
The research aims to single out the maintenance actions to perform on a series arranged components system each one constituted by elements in parallel and maintained only during some planned stops. The considered system has to periodically carry out missions during which the system failure is a critical event for their own success. That being so, the faced problem is here to assure the maximum reliability level up to the next planned stop. For this reason an exact algorithm is proposed in order to individuate the set of components on which performing maintenance actions and for each of them determining the number of elements that must be maintained so as the maximum reliability level is ach…