Search results for " heuristic"
showing 10 items of 54 documents
A Self-Adapting Approach for Forecast-Less Scheduling of Electrical Energy Storage Systems in a Liberalized Energy Market
2013
In this paper, an original scheduling approach for optimal dispatch of electrical Energy Storage Systems (ESS) in modern distribution networks is proposed. The control system is based on fuzzy rules and does not use forecasts since it repairs the past history according to the real time data on the electrical energy cost, renewable energy production and load. When the system detects a worsening of performances, the fuzzy logic rule-based control system self-adapts its membership functions using an economic indicator. The common use, in the relevant literature, of forecasted values in such systems can lead to large errors and economic losses. Moreover the speed of calculation guaranteed by th…
A review on discrete diversity and dispersion maximization from an OR perspective
2022
Abstract The problem of maximizing diversity or dispersion deals with selecting a subset of elements from a given set in such a way that the distance among the selected elements is maximized. The definition of distance between elements is customized to specific applications, and the way that the overall diversity of the selected elements is computed results in different mathematical models. Maximizing diversity by means of combinatorial optimization models has gained prominence in Operations Research (OR) over the last two decades, and constitutes nowadays an important area. In this paper, we review the milestones in the development of this area, starting in the late eighties when the first…
Lower and upper bounds for the mixed capacitated arc routing problem
2006
This paper presents a linear formulation, valid inequalities, and a lower bounding procedure for the mixed capacitated arc routing problem (MCARP). Moreover, three constructive heuristics and a memetic algorithm are described. Lower and upper bounds have been compared on two sets of randomly generated instances. Computational results show that the average gaps between lower and upper bounds are 0.51% and 0.33%, respectively.
Some Aspects Regarding the Application of the Ant Colony Meta-heuristic to Scheduling Problems
2010
Scheduling is one of the most complex problems that appear in various fields of activity, from industry to scientific research, and have a special place among the optimization problems In our paper we present the results of our computational study i.e an Ant Colony Optimization algorithm for the Resource-Constrained Project Scheduling Problem that uses dynamic pheromone evaporation.
Perceived Onset Time of Medical Conditions: The Interplay Between Subjective Fear and Risk in Four Lifestyle Domains
2022
Engaging in unhealthy behaviors (e.g., smoking, drinking) and not engaging in healthy ones (e.g., exercising, consuming fruit and vegetables) are both relatively prevalent among individuals despite the available information about their risks for health. People’s perception of an event’s time course can be used to gauge their risk perception for that event thus casting light on any possible misperception and suggesting directions for health-promoting interventions. This study investigates people’s perception of the time of onset of 5 noncommunicable diseases (e.g., “having high blood pressure”) associated with 4 health-related behaviors: Smoking, drinking, exercising, and eating fruit and v…
Greedy and K-Greedy algoritmhs for multidimensional data association
2011
[EN] The multidimensional assignment (MDA) problem is a combinatorial optimization problem arising in many applications, for instance multitarget tracking (MTT). The objective of an MDA problem of dimension $d\in\Bbb{N}$ is to match groups of $d$ objects in such a way that each measurement is associated with at most one track and each track is associated with at most one measurement from each list, optimizing a certain objective function. It is well known that the MDA problem is NP-hard for $d\geq3$. In this paper five new polynomial time heuristics to solve the MDA problem arising in MTT are presented. They are all based on the semi-greedy approach introduced in earlier research. Experimen…
Optimization of Data Harvesters Deployment in an Urban Areas for an Emergency Scenario
2013
International audience; Since its appearance in the VANETs research community, data collection where vehicles have to explore an area and collect various local data, brings various issues and challenges. Some architectures were proposed to meet data collection requirements. They can be classified into two categories: Decentralized and Centralized self-organizing where different components and techniques are used depending on the application type. In this paper, we treat time-constrained applications in the context of search and rescue missions. For this reason, we propose a centralized architecture where a central unit plans and manages a set of vehicles namely harvesters to get a clear ove…
A parallel simulated annealing approach to the K shortest loopless paths problem
1997
The k shortest loopless paths problem is a significant combinatorial problem which arises in many contexts. When the size of the networks is very large the exact algorithms fail to find the best solution in a reasonable time. The aim of this paper is to suggest parallel efficient algorithms to obtain a good approximation of the solution to the k shortest loopless paths problem between two arbitrary nodes, when the network size is large. The heuristic used is known in literature as Simulated Annealing. Preliminary tests have been conducted for evaluating the validity of the proposed algorithms. The quality of the obtained results represents a significant base for further experimentations.
Dal quartetto alla jam session: strategie conversazionali e razionalità
2020
In questo articolo sosterrò che le nostre concezioni di linguaggio e comunicazione mutano in funzione dell’accezione di razionalità che viene assunta. In particolare, mostrerò come ad un modello di razionalità olimpica e assoluta – ovvero ad un modello di animale umano che ragiona seguendo le leggi della logica formale – corrisponda una concezione della comunicazione esemplificata dall’immagine del quartetto, un complesso musicale in cui quattro musicisti suonano insieme seguendo delle regole fisse e stabilite prima di iniziare a suonare. Questa immagine sembra ben rispecchiare i modelli di comunicazione proposti da Paul Grice e Jurgen Habermas,dominanti nello studio del linguaggio fino agl…
La representación sindical en España: cobertura y límites
2018
El objetivo de este artículo es realizar una aproximación al sistema de representación unitaria en la empresa en España a partir de una explotación estadística de los datos de las elecciones sindicales. Se trata de conocer aspectos como el alcance de la representación unitaria, la participación de los asalariados y la audiencia electoral de los sindicatos, con el objetivo de delimitar su representatividad y legitimidad. Nuestro trabajo se centra en el análisis de los tres últimos períodos electorales (2003-2007, 2007-2012 y 2012-2015), con objeto de evaluar el impacto del ciclo económico sobre la representación de los asalariados. The objective of this article is to make an approach to the …