Search results for " Network"
showing 10 items of 6428 documents
Artificial neural network applied to the discrimination of antibacterial activity by topological methods
2000
Abstract A new topological method that makes it possible to discriminate the active and inactive molecules on the basis of their chemical structures is applied in the present study to the antibacterial agents. This method uses neural networks in which training algorithms are used as well as different concepts and methods of artificial intelligence with a suitable set of topological descriptors. It is possible to obtain a QSAR interpretation of the information contained in the network after the training has been carried out.
Application of adaptive models for the determination of the thermal behaviour of a photovoltaic panel
2013
The use of reliable forecasting models for the PV temperature is necessary for a more correct evaluation of energy and economic performances. Climatic conditions certainly have a remarkable influence on thermo-electric behaviour of the PV panel but the physical system is too complex for an analytical representation. A neural-network-based approach for solar panel temperature modelling is here presented. The models were trained using a set of data collected from a test facility. Simulation results of the trained neural networks are presented and compared with those obtained with an empirical correlation.
An Encoding in Metaheuristics for the Minimum Communication Spanning Tree Problem
2009
Problem-specific encodings can improve the performance of metaheuristics, such as genetic algorithms or simulated annealing. This paper studies the link-biased (LB) encoding, which is a tree representation, and applies metaheuristics using this encoding to the minimum communication spanning tree (MCST) problem. Given the communication requirements of the nodes, the MCST problem seeks a communication spanning tree with minimum total cost. Optimal solutions for MCST problems are similar to minimum spanning trees (MSTs), and the LB encoding exploits this property by encoding trees similar to MSTs with higher probability. The paper investigates how to systematically design problem-specific enc…
Extraction of Endmembers from Spectral Mixtures
1999
Abstract Linear spectral mixture modeling (LSMM) divides each ground resolution element into its constituent materials using endmembers which represent the spectral characteristics of the cover types. However, it is difficult to identify and estimate the spectral signature of pure components or endmembers which form the scene, since they vary with the scale and purpose of the study. We propose three different methods to estimate the spectra of pure components from a set of unknown mixture spectra. Two of the methods consist in different optimization procedures based on objective functions defined from the coordinate axes of the dominant factors. The third one consists in the design of a neu…
Setpoints compensation in industrial processes via multirate output feedback control
2013
This paper investigates the setpoints compensation for a class of complex industrial processes. Plants at the device layer are controlled by the local regulation controllers, and a multirate output feedback control approach for setpoint compensation is proposed such that the subsystems can reach the dynamically changed setpoints and the given economic objective can also be tracked via certain economic performance index (EPI). First, a sampled-data multivariable direct output feedback proportional integral (PI) controller is designed to regulate the performance of the subsystems. Second, the outputs and control inputs of the plants at the device layer are sampled at operation layer sampling …
La valorizzazione dell’agoralimentare di qualità e lo sviluppo del territorio
2012
Obiettivo dello studio è indagare la capacità di valorizzazione del patrimonio territoriale in alcuni ambienti della Sicilia (ricadenti nelle province Trapani) posti a confronto con un contesto di riferimento, individuato in Toscana (nella provincia di Siena). Questo studio ha indagato entrambe le aree attraverso due approcci complementari: la relazione tra le attività agricole e l’ambiente – con l’applicazione del DPSIR (Driving forces, Pressures, States, Impacts, Responses; Trisorio, 2004) – e il sistema relazionale degli operatori dei comprensori attraverso la SNA (Social Network Analysis). Si sono pertanto indagati gli aspetti relazionali del sistema produttivo del vino Alcamo DOC e del…
Local economies and consumer participation: the organic food fairs
2012
New consumption habits stand out against the idea of a rational consumer, which is aimed at maximizing utility according to budget constraint. Presently, people have the tendency to behave differently according to various purchase opportunities; a significant role is played by both ethical sides and selfless motivations. These new trends fall within the context of a new social paradigm that foresees postmodern society’s rise. Consumers have the tendency to use the market as an arena in which political, ethical and environmental issues may arise, starting a new trend of an alternative consumption called “political consumerism”. In this paper we’ll try to understand how new consumption habits…
La valorizzazione dell’agroalimentare di qualità e lo sviluppo del territorio
2012
Obiettivo dello studio è indagare la capacità di valorizzazione del patrimonio territoriale in alcuni ambienti della Sicilia (ricadenti nelle province Trapani) posti a confronto con un contesto di riferimento, individuato in Toscana (nella provincia di Siena). Questo studio ha indagato entrambe le aree attraverso due approcci complementari: la relazione tra le attività agricole e l’ambiente – con l’applicazione del DPSIR (Driving forces, Pressures, States, Impacts, Responses; Trisorio, 2004) – e il sistema relazionale degli operatori dei comprensori attraverso la SNA (Social Network Analysis). Si sono pertanto indagati gli aspetti relazionali del sistema produttivo del vino Alcamo DOC e del…
The Beauty of the Commons? Consumers Participation in Food Community Networks
2012
Why are consumers increasingly joining farmers to co-produce and transact sustainable foods world-wide? May these networks be a new tool to promote sustainable practices? As stated by Sandler (2010): “Longitudinal collective action environmental problems are likely to be effectively addressed only by an enormous number of individuals each making a nearly insignificant contribution to resolving them”. Consumers-farmers networks may serve this scope by inducing individual actors to change their preferences towards sustainable products. However participation in these networks is still not well understood. On one hand new institutional economics explains consumers joining farmers in creating a n…
A wireless sensor network for vineyard management in Sicily (Italy)
2013
Wine quality depends on many factors, such as the choice of variety, stock, training system, pruning as well as environmental parameters and cultivation techniques performed in the vineyard. Monitoring the micro-climate of grapevine allows to conveniently perform the most important cultivation techniques (soil management, pesticide treatments, green pruning, harvest) thus reducing the operating costs of the vineyard, and increasing the overall quality of the grapes. The aim of the present study is to monitor the micro-climate of grapevine in order to control spring period hazards, to reduce the operating costs of the vineyard and to increase the quality of grapes. For this purpose a Wireles…