1,721,278 research outputs found
Sagar : A South Asia Research Journal
No full textSagar - A South Asia Research Journal Sujet : Sagar seeks innovative academic writings on the history, society, culture, literature, religion, economics, technology and media of South Asia. The journal was established in 1993 and is published annually online and in print by The South Asia Institute at The University of Texas at Austin. As of August 2012, we have made the transition to peer-reviewed status. Submissions are now coordinated by an editorial collective of UT graduate stude..
A Novel Beluga Whale-Jaya Optimization for Effective EV Charge Scheduling in Power Generation
Full text linkWhile considering the provision of the safest environment, it leads to the rapid growth of Electric Vehicles (EVs) that spread over the markets based on features like improvement of charging stations, economy, battery technology, and price. Moreover, the EV charging station placement issues are regarded as facility location issues. In addition, EV charging station placement issues have concerns about the electric distribution systems, the system losses, and the total number of convergences over the traffic network for voltage deviations. The voltage profile enhancement and loss minimization are considered two major issues obtained over the distributed model and are commonly equipped along with the shunt capacitors for reactive power compensations. A novel EV charging model is developed based on hybrid optimization approaches to tackle the issue. The charge level parameters of regional EV charging schedules are tuned with the help of a developed hybrid approach named Beluga Whale-Jaya Optimization (BWJO) derived via Beluga whale optimization (BWO) and JAYA optimization (JA) to attain the minimization of greenhouse gas emission acquired from electricity. Thus, the developed model has offered an enhanced performance rate when contrasted with conventional EV charging schedules schemes
A Novel Bi-directional Wireless Power Transfer Design for Smart Homes
No full textThe continuous increase of greenhouse gases has led to the melting of glaciers, rising sea levels, and a decline in rain forests. To reduce the impact of greenhouse gases, we need to reduce the consumption of fossil fuels, which is possible through the use of electric vehicles (EV’s) energy storage systems, in order to interchange the energy between distributed grids or residential electrical appliances supplied with EV’s batteries. Thus, the given paper proposes the design of a bi-directional wireless battery charger (BDWBC) for smart homes. The design complies with the synchronous rectification circuit associated with primary and secondary half-bridge (H-bridge) converters. The proposed system is implemented using MATLAB Simulink and is validated against the existing recent works based on evaluation metrics such as charging power (watts) and efficiency (%). Thus, the given wireless power transfer (WPT) approach leads to distributed energy resource management with maximum charging power and efficiency for smart homes
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
Control strategy for a bidirectional wireless power transfer system with Vehicle to Home functionality
No full textThe advancements in the charging strategy of electric vehicles will have inevitable effects on the electrical grid in the coming future. Electric vehicle battery chargers are able to perform the bidirectional power transfer according to the vehicle-to-grid concept and will offer valuable services to the distribution grid or to the domestic grid of the vehicle owner. The wireless power transfer battery chargers offer the opportunity for a more safe and user-friendly approach to electric vehicles for people who are not confident with technological apparatuses. Bidirectional wireless power transfer chargers capable of vehicle to grid services are the natural evolution of the above-mentioned concepts. This paper faces the topic of developing the control algorithms for such a battery charger, focusing on the needs of the power conversion stages involved in the functioning of a charger enabled for vehicle to home operation. At first, the separation of the control algorithms into two levels is explained, and then the interaction between the algorithms of the internal and external level is introduced. It was decided to design controllers as simple as possible in implementing the control algorithms. This has made it possible to adopt techniques well known in the scientific community for their design and to contain the computational resources necessary for their implementation. Despite the simplicity of the controllers, the introduction and management of the interactions between the various algorithms has made it possible to develop an overall control strategy that at the same time respects the voltage and current limits set by the grid and the battery and also avoids exceeding the maximum operating conditions of the static converters that constitute the system. The algorithms and the relevant controllers are developed one by one in the continuous time domain, using techniques based on the analysis of Bode diagrams of the transfer functions involved in the operation of the system. In designing the controllers, the effects of their subsequent implementation in a discrete time domain are considered together with the effect of the transmission delay originated by the data exchange between the two sections of the system. The discretization of the controllers has been performed using the Tustin method. The performance of all algorithms has been separately verified in the discrete time domain using simulations developed in the Matlab/Simulink environment. Finally, the functioning of the complete control strategy has been successfully checked in the same environment
Design and Analysis of a Robust High-Density Single-Phase Isolated Buck Converter System For Regulated Power Supply
Full text linkThis paper proposes a single-phase isolated buck power converter system that extracts and transmits the oscillating ripple energy of the primary buck inductor current to the secondary coil. This topology is a modification of the conventional buck configuration in which the single power inductor is substituted for by a pair of coupled inductors to build an isolated secondary output. The secondary coil delivers the required power due to the time-varying magnetic field developed by the oscillating part of the primary inductive current. Hence it eradicates the requirement of setting up a separate DC regulated supply for the main switch of the buck converter and results in a DC-DC switching converter, including a primary coil besides the existing typical wired output of the buck converter. This paper addresses the relevant operating principle and offers results for the simulation prototype by using a single-phase isolated buck structure, which attains simultaneous Buck conversion of conventional output and delivers the power to the secondary load as well
Analysis and Comprehensive Comparison of Wireless Power Transfer System Using SS and SP topology for Electric Vehicle Charging
No full textWireless power transfer (WPT) system now becomes one of the most promising innovations that offer the benefits of more safety, ease of usability, and increased charging range of moving electric vehicles (EVs) compared to conventional wired charging. In real-world applications, suitable measures should be taken to make up for the power transfer coils so that the output power increases and the input apparent power rating of the power converter decreases. Using the idea of the coupled inductor, this paper analyses the concepts employed in the series-series (SS) and series-parallel (SP) compensation topologies of the WPT systems to select an appropriate compensation topology for EV charging. With the help of MATLAB/SIMULINK, the link among the effects of mutual inductance, load, and working frequency on the voltage gain has been analyzed and compared respectively. The simulation findings reveal that the SS compensation topology is better for system applications with lower loads, whereas the SP topology is preferable for systems with higher loads. There is the best possible load for a fixed transfer distance that optimizes the voltage gain and system performance. Furthermore, this study analyses the dependencies of the coupling coefficient and the receiving side quality factor on the transmitting side compensation design using SS and SP topologies. Hence, this article could be used as a reference for a developer to determine the best compensation topology of the WPT system based on EV applications
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
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