1,721,069 research outputs found
Simulation of the Volt/Var Control in Distribution Feeders by Means of a Networked Multiagent System
Full text linkThe adoption of networked multiagent systems (MAS) has been recently proposed for the solution of the volt/var control (VVC) problem in distribution feeders. However, constraints and limitations due to the communication network, to the dynamic behavior of power system components and regulators, as well as to the measurement uncertainties of the adopted sensors need to be specifically analyzed for the design of the MAS. For this purpose, a cosimulation platform has been built by the integration of two simulation tools: 1) the electromagnetic transient program EMTP-rv; and 2) the communication network simulator Riverbed-OPNET Modeler. This paper presents the modeling and simulation of an asynchronous leaderless MAS-based approach that coordinates the reactive power outputs of a set of power compensators equipped with phasor measurement units via a shared band-limited packet-switched digital communication network. The effects of communication network latency and packet loss on the VVC performances are analyzed for two unbalanced IEEE Test feeders equipped with on-load tap changer transformers. The paper compares the results obtained by using a transmission control protocol (TCP) and a user datagram protocol (UDP), for different levels of background traffic (BT) and different packet discard ratios (PDRs) in the communication links
Two-stage Scheduling of Electrical Vehicle Charging Station Clusters in a Community of DC Microgrids
No full textThe paper deals with the day-ahead scheduling of an energy community with the presence of DC microgrids equipped with clusters of bidirectional electric vehicle (EV) charging stations. A two-stage optimization procedure is proposed to coordinate the operation of the community characterized by the exchanges of energy among the microgrids and the operation of each EV charging station in each cluster. The first stage implements a distributed scheme based on the alternating direction method of multipliers (ADMM) to provide the scheduling of each community participant. In this stage, for each microgrid, all the EV batteries connected to the charging stations are aggregated in a single storage unit. The second stage provides the detailed scheduling of each charging station, in agreement with the energy transactions defined by the first stage and exploiting vehicle-to-grid services
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
ICT-power co-simulation platform for the analysis of communication-based volt/var optimization in distribution feeders
No full textThe paper presents an ICT and power co-simulation platform for the analysis of the volt/var control and relevant optimization in medium voltage distribution feeders, achieved by means of a system of distributed controllers coordinated via a shared band-limited digital communication network. The platform has been built by realizing the interface between two specific simulation environments: the Electromagnetic Transient Program EMTP-RV and the communication network simulator Opnet Modeller. The preliminary results provide basic indications on the expected performances of the considered communication-based strategies for different traffic congestion levels and load/generation dynamic variations
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
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