1,720,959 research outputs found
An event driven Smart Home Controller enabling consumer economic saving and automated Demand Side Management
No full textThis paper proposes the design of a Smart Home Controller strategy providing efficient management of electric energy in a domestic environment. The problem is formalized as an event driven binary linear programming problem, the output of which specifies the best time to run of smart household appliances, under a virtual power threshold constraint, taking into account the real power threshold and the forecast of consumption from not plannable loads. The optimization is performed each time the system is triggered by proper events, in order to tailor the controller action to the real life dynamics of an household. This problem formulation allows to analyze relevant scenarios from consumer and energy retailer point of view: here overload management, optimization of economic saving in case of Time of Use Tariff and Demand Side Management have been discussed and simulated. Simulations have been performed on relevant test cases, based on real load profiles provided by the smart appliance manufacturer Electrolux S.p.A. and on energy tariffs suggested by the energy retailer Edison. Results provide a proof of concept about the consumers benefits coming from the use of local energy management systems and the relevance of automated Demand Side Management for the general target of efficient and cost effective operation of electric networks. © 2012 Elsevier Ltd
Dynamic Bandwidth Allocation in Satellite Networks
No full textThis work presents an adaptive control approach for queue-based Bandwidth-on-Demand (BoD) procedures in geostationary satellite networks. In queue-based protocols, the controller objective is to drive the buffer queue length to a certain target queue length. The proposed protocol is based on the construction of a certain number of models (MRs) that represents a particular statistical network behavior in a way to obtain the above mentioned reference queue length. The reference queue length is computed as a weighted sum of the outputs of the different MRs. By varying on-line the target queue length a trade-off between efficient exploiting of bandwidth and reduction of queuing delay is achieved
A Novel Approach to Generation Portfolio Optimization by using Genetic Algorithms and Stochastic Methods
No full textIn this paper we present the Portfolio Optimization Problem in the electricity generation framework. We consider traditional and fully controllable energy sources together with wind source, strongly supported by economical benefits but exposed to intermittent generation volatility. Due to the statistical uncertainty about parameters, we formalize the optimization problem in a probabilistic sense and solve it by using Genetic Algorithms
A cross-layer approach to dynamic bandwidth allocation in Satellite networks
No full textThis work presents an innovative cross-layer approach to dynamic bandwidth allocation (BoD) in Satellite DVB-RCS networks. The algorithm is based on the assumption that, by managing the traffic at IP level through interaction with MAC level, a meaningful reduction in packet loss can be achieved, thus resulting in better resource exploitation. The proposed mechanism has been embedded in a consolidated control scheme for dynamic bandwidth allocation ([23], [1]). The interaction consists in the computation of the exact amount of MAC cells to send to the air interface during the next frame; based on this computation, the proper number of IP packets are segmented, transmitted to the MAC layer and queued in the MAC buffers. In this way, a twofold result is obtained: 1) no duplication of the scheduling function, scheduling can be performed at IP layer only, and 2) avoidance of overflows of MAC buffers. Simulations results, obtained by Opnet®, confirm the effectiveness of the proposed approach. © 2010 Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering
Multipath routing by network decomposition and traffic balancing
No full textIn this work we face the routing task defined as an optimal control problem, with control variables representing the percentages of each flow routed along the available paths(multipath routing), and a cost function which accounts for balanced traffic flow across the network resources. A further issue considered in this paper is the possibility/opportunity of splitting the given network in sub-networks, each one controlled by a separate subset of variables. This of course designs a decomposition of the original control problem in a set of easier-to-be-dealt-with lower dimensional problems, leading to separate minimum unbalancing indices which sum up to a value lower than the minimum global one achievable in the no decomposition case. Some numerical simulation results validate the procedure. Copyright © 2010 The authors
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
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