1,720,956 research outputs found
Rectifier design for radio frequency energy harvesting system
Get PDFThis thesis presents the development of rectifying circuits suitable for Radio Frequency (RF) energy harvesting application with dual-band capabilities. The main contribution of this thesis is the development of compact dual-band two-stage rectifier with high efficiency. Firstly, a voltage doubler rectifying circuit is designed to get a compact size. A source-pull simulation of matching circuit is used to find the optimal load impedance and enhance the conversion efficiency over the frequency range. The accuracy of the design has been justified by the simulation and measurement results. Secondly, a dual-band impedance matching network based on transmission line is developed. A short stub and general impedance transformer are designed to match different complex impedance at the two operating frequencies. Measurement results have fully demonstrated. Thirdly, a new rectifier circuit is proposed. It employs a dual-band multi resonant matching network and a high efficiency modified quadruplor rectifier for harvesting the ambient RF power at both 2.45 GHz Global System for Mobile Communications (GSM) and 5.8 GHz Wireless Local Area Network (WLAN). An attempt was made for matching network with a series of combination of a capacitor and inductor with a parallel LC tank. For rectifier circuit part, low power harvested from the RF is boosted up using two-stage of voltage multiplier and the input capacitor is rearranged to be in parallel connection to get smaller size and uniform pressure on diode. The prototypes are developed, and simulation results are obtained. The proposed rectifier is proven to exhibit greatly higher output voltage and efficiency compared to the conventional circuit. The rectifier is designed on the FR-4 board. Its capability of working within two frequency bands at 2.45 GHz and 5.8 GHz is verified by measurement. The proposed rectifier has met the requirement of high conversion efficiency (79.1% and 78.4% at the respective 2.45 GHz and 5.8 GHz), and able to boost up to the maximum voltage level of 14V at 20 dBm input power. Hence, the aims of this research have been achieved and are practically suitable for the use in wireless sensor networks and low power devices
Smart home system using internet of things: design, implementation and sample codes
Get PDFSmart home control system (SHCS) can be integrated into an existing home appliances to reduce the need for human intervention, increase security and energy efficiency. It is still an open research due to difficulties such as network distance, signal interference, user friendliness, high cost, and high power consumption. This book reviews various topics on smart home technologies, including control system, smart home network, smart home appliance and sensor technologies for smart home. A smart home system using internet of things was proposed using internet of things (IoT) and four types of sensors, including PIR, temperature, ultrasonic, and smoke
gas sensor for automatic environmental control and intrusion detection. Hardware, software, and test field design will be discussed. The performance of the prototype of smart home system will be evaluated. First, experiments on various sensors will be conducted. Next, the communication channel using wireless and Ethernet modules will be discussed. Moreover, the overall SHCS will be evaluated in terms of hardware and software performance with additional solar charger to improve power efficiency
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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