1,720,956 research outputs found
FPGA Implementation of a Parallel DDS for Wide-Band Applications
Full text linkIn this paper, the authors propose a parallel Digital Direct Synthesis (DDS) suitable for digital ultra wide-band systems. The proposed architecture offers the possibility to generate sine and/or cosine waves with a user-defined level of parallelism without the necessity to increase the clock frequency. It has been designed in SIMULINK coded in VHDL at RTL level and finally implemented on a Xilinx FPGA. Synthesis and place & route have been performed using the XILINX VIVADO toolchain. Results are provided in terms of hardware resources, speed, and power consumption considering a level of parallelism equal to 4. Implementation results show a low area complexity and very reduced power consumption that coupled with the flexibility in terms of parallelism level make this DDS useful in ultrawideband low-power systems. In particular, the DDS is characterized by an energy per operation of about 91 pJ. The reduced hardware complexity allows its implementation on low-cost FPGA
FPGA Implementation of a BPSK Modulator with Frequency Hopping
Full text linkPSK modulations are very widespread in communication due to their robustness to the noise. In order to avoid interference or for anti-jamming purposes, frequency hopping may be applied. In this work we present an FPGA implementation of a BPSK modulator based on frequency hopping. The results shows good performance, more than 300 MHz of clock system, low area occupation and low power dissipation (about 100 mW)
Soil Moisture Estimation based on the RSSI of RFID Modules
No full textNowadays the RFID technology and Internet of Things are becoming empowering and enabling tools in various fields, including smart and precision agriculture. The aim of this research is to propose an innovative system for the detection of soil moisture based on the use of standard UHF RFID tags and on the measurement of the received signal strength detected by a reader that can be hosted on board drones or farm vehicles. The reader detects the RSSI received from tags placed below the ground level and according to the measured value is able to discriminate if the ground is dry or wet. Microwave propagation is, in fact, strongly influenced by the presence of water in the soil and by exploiting the instantaneous and average RSSI values it is possible to discriminate the conditions of dry and wet soil and, thus, optimize irrigation in a wide area. The results obtained by using a first prototype show that the approach is suitable for any type of soil: sandy, clayey or loamy; further studies must be conducted in order to identify different levels of soil moisture and to determine the moisture levels at different depths
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
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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