1,721,151 research outputs found
A decentralized approach for enabling advanced ancillary services through distributed energy sources
Full text linkThis thesis reports the results carried out by the author during the three-year activities of the XXXV cycle of the Ph.D. course in Electrical and Information Engineering at Politecnico di Bari. The main goal of this work was to implement a decentralized approach to enable the provision of Ancillary Services (AS) by means of Distributed Energy Resources (DERs).
As a first step, an analysis of Regulations, Directives, and Network Codes at the national and European level was carried out to define the future framework of the electricity market. In addition, papers and technical reports concerning eight European projects, such as SmarNet, CoordiNet, FLEXCoop, OSMOSE, inteGRIDy, eDREAM, ADDRESS, and evolvDSO have been analyzed with the aim to define the state of the art about the provision of AS by means of DERs. In particular, a set of coordination schemes was identified from those proposed in the literature to coordinate the use of DERs among Transmission System Operators (TSOs) and Distribution System Operators (DSOs). These coordination schemes are classified into centralized and decentralized architectures, depending on the possibility of System Operators of managing their respective networks. In addition, the main methodologies proposed in the literature to perform optimal dispatch of flexibility resources in a TSO-DSO coordination framework, taking technical and grid constraints into account, have been identified and presented.
In order to enable DERs in AS provision and coordinate system operators in their usage, a few methodologies suitable for decentralized architectures were developed and presented in this work. In particular, a new algorithm based on a three-phase optimal power flow routine for mapping the flexibility area at the point of interconnection (POI) between transmission and distribution grids was provided. Furthermore, two alternative methodologies to aggregate flexibility resources located in distribution networks interfaced with the TN in multiple POIs were described. In addition, a Benders decomposition algorithm able to optimize TN and DN flexibility resources for congestion management in a few decentralized coordination schemes was also implemented. The proposed methodologies were validated by means of simulation tests conducted on a power system including transmission and distribution grids.
The last part of this thesis investigated how innovative grid services, such as Synthetic Inertia (SI) and Fast Frequency Response (FFR), may be also provided through fast control dispatchable resources located at the distribution grid level. With this aim, a low-cost controller for end-user applications able to generate a SI law for dispatchable DERs was developed and tested through Power Hardware-in-the-Loop (PHIL) tests. Similarly, PHIL tests were also carried out to investigate the capability of LED lamps of public lighting systems to be controlled with the aim to provide SI and FFR actions. Experimental results validated the proposed decentralized approaches
Wearable Monitoring Systems
No full textWearable Monitoring Systems Edited by: (editors) Annalisa Bonfiglio Danilo E. De Rossi As electronic and information systems on the human body, the role of wearable embedded systems is to collect relevant physiological information, and to interface between humans and local and/or global information systems. Within this context, there is an increasing need for applications in diverse fields, from health to rescue to sport and even remote activities in space, to have real-time access to vital signs and other behavioral parameters for personalized healthcare, rescue operation planning, etc. This book's coverage spans all scientific and technological areas that define wearable monitoring systems, including sensors, signal processing, energy, system integration, communications, and user interfaces. A diverse collection of applications is used to illustrate the principles and practices introduced, while providing a broad overview and critical analysis of the field of wearable technologies. Discusses all elements of wearable systems, including sensors, energy generation, signal processing and communications systems; Reviews recent work on wearable systems based on a e-textile technology; Describes key applications of wearable systems in a variety of fields, such as sports, wellness and fitness, health monitoring and diagnostics, protective garments for emergency and work in noxious and dangerous environments, and applications in space and planetary explorations; Offers an overview of market challenges and perspectives. © Springer Science+Business Media, LLC 2011. All rights reserved
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
CONDUCTIVE FIBER MATERIALS
No full textThe present invention relates to a fiber material, in particular a textile which is conductive. The fiber material includes a base textile material on the surface of which a plurality of nanoparticles are deposited and a conductive polymer layer on top of the nanoparticles
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
- …
