1,720,957 research outputs found
Metodi e tecnologie abilitanti per la gestione intelligente dell'energia
No full textLe reti intelligenti sono reti elettriche in grado di gestire le azioni di diversi utenti e di fornire energia in modo sostenibile, economico e sicuro. Esse permettono di monitorare il consumo di energia e di stimare in tempo reale i loro parametri caratteristici. Ciò consente di evitare perdite di potenza non programmate e di semplificare non solo gli scambi di energia tra l'utente finale ed il fornitore, ma anche tra gli utenti stessi, al fine di ottenere un'ottimizzazione dei consumi e di ridurre i costi. La configurazione delle reti elettriche è rimasta invariata per lungo tempo; oggigiorno, tali reti stanno subendo una graduale trasformazione grazie alla disponibilità delle moderne tecnologie dell'informazione e della comunicazione.
Questa tesi si concentra su diversi metodi e tecnologie nel campo della gestione dell'energia. Nel lavoro svolto si prende in considerazione la gestione delle risorse energetiche in una comunità di utenti. Si assume che ciascun utente disponga di una fornitura di gas e di una fornitura di energia elettrica, quest'ultima erogata attraverso una micro-rete intelligente residenziale a bassa tensione. In questo ambito si affrontano le seguenti tematiche specifiche: a) gestione intelligente della richiesta di energia da parte degli utenti della micro-rete; b) stima degli stati e dei parametri caratteristici della rete elettrica; c) pianificazione di una rete radio per la misura della fornitura di gas.
La prima tematica riguarda lo sviluppo di una strategia autonoma e distribuita per la gestione dell'energia; l'algoritmo ideato è basato sulla teoria dei giochi e mira all'ottimizzazione del flusso di energia tra gli utenti della micro-rete. Questo algoritmo consente a ciascun utente di controllare e gestire i propri consumi, richiedendo o fornendo energia nei periodi di tempo desiderati, e sfruttando la conoscenza di informazioni statistiche del resto della micro-rete.
La seconda tematica riguarda la stima dello stato in una rete elettrica: il monitoraggio di una rete elettrica ha sempre rappresentato un'azione fondamentale, ma ha acquisito ancora maggiore importanza negli ultimi anni con l'avvento di nuove tecnologie e delle sorgenti di energia rinnovabile. A tale scopo, si affronta il problema del filtraggio nel caso di modelli a stati contenenti delle nonlinearità. La soluzione proposta si basa sullo sviluppo di un opportuno grafo di fattori e sull'applicazione ad esso dell'algoritmo noto come somma di prodotti.
Infine, il terzo tema di ricerca affrontato è relativo alla pianificazione di una rete radio per lo smart metering del consumo di gas domestico. La risoluzione di questo problema richiede la disponibilità di una tecnica per la stima delle perdite propagative in un collegamento radio a 169 MHz. Il metodo sviluppato si basa su una moderna tecnica di apprendimento automatico che è nota come support vector machine (SVM) e che viene addestrata mediante un insieme di misure sperimentali.Smart Grids are electricity networks able to manage the actions of all users connected to them in a way to efficiently deliver power supply in a sustainable, economic, and secure fashion. They allow to monitor energy consumption and to estimate their characteristic parameters in real-time, so avoiding unplanned power failures and facilitating not only the exchange of energy between a provider and its end users, but also among the users themselves; this optimizes power consumption and reduce costs. Traditional electrical grids are able to deliver energy from power plants to their end customers; their configuration has remained substantially unchanged for a long time. Nowadays, such grids are undergoing a gradual transformation thanks to the availability of modern information and communication technologies.
This thesis focuses on different methods and technologies in the field of energy management. In the developed work, energy management in a community of users is taken into consideration. It is assumed that each user is connected to a gas distribution network and to a power network; moreover, electricity is provided through a low-voltage residential smart micro-grid. In this scenario the following three main topics are investigated: a) demand side management of micro-grid users; b) state estimation of a power grid; c) planning of a radio network for the smart metering of gas supply.
The first topic concerns the development of a autonomous and distributed strategy for demand-side energy management; the devised algorithm is based on game theory and aims at the optimization of the energy flow among the users of a micro-grid. Each user is allowed to monitor and manage his/her power consumption, requiring or supplying energy over specific time intervals, and exploiting the knowledge of statistical information about the consumption of the remaining part of the micro-grid.
The second topic concerns the state estimation of a power grid: monitoring the state of a power grid has always represented a fundamental task, which has acquired an even greater importance in the last years because of the availability of new technologies and of renewable energy sources. To this aim, the filtering problem for nonlinear state-space models is tackled. The proposed solution is based on the development of a proper factor graph and on the application to it of the so called sum of products algorithm.
Finally, the third topic concerns the planning of wireless network for the smart metering of gas domestic consumption. Solving this problem requires the availability of a technique for the estimation of the propagation losses in a radio link at 169 MHz. The developed method is based in a modern machine learning technique, which is known as support vector machine (SVM) and is trained by means of a set of experimental data
A Bayesian Demand-Side Management Strategy for Smart Micro-Grid
No full textIn this manuscript a novel strategy for distributed and autonomous demand-side energy management among users of a low-voltage micro-grid is developed. Its derivation is based on: a) modelling the energy consumption scheduling of the shiftable loads that belong to a given user as a noncooperative two-player game of incomplete information, in which the user itself plays against an opponent collecting all the other users of the same micro-grid; b) assuming that each user is endowed with statistical information about its behavior and that of its opponent, so that it can choose actions maximising its expected utility. Numerical results evidence the efficacy of the proposed strategy when employed to manage the charging of electric vehicles in a micro-grid
Demand-side management in a smart micro-grid: A distributed approach based on Bayesian game theory
No full textIn this manuscript a novel strategy for distributed and autonomous demand-side energy management among users of a low-voltage micro-grid is developed. Its derivation is based on: a) modelling the energy consumption scheduling of the shiftable loads that belong to a given user as a noncooperative two-player game of incomplete information, in which the user himself plays against an opponent collecting all the other users of the same micro-grid; b) assuming that each user is endowed with statistical information about his behavior and that of its opponent, so that he can choose actions maximising his expected utility. Numerical results evidence the efficacy of the proposed strategy when employed to manage the charging of electric vehicles in a micro-grid
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
