1,721,063 research outputs found
Comparative Performance of Non-linear Distortion Effects in OFDM-RoF Link
No full textRecently, the integration of Orthogonal Frequency Division Multiplexing (OFDM) and Radio over Fiber (RoF) technique emerged the possibility of cost-effective and high data rate ubiquitous wireless networks. However, the nonlinear effects can severely degrade the performance of RoF as well as OFDM system. In this paper, the performance of OFDM-based RoF link with Mach-Zehnder modulator nonlinearity effects have been analyzed and simulated and then compared with single-carrier modulation case. Later, offset biased pre-distortion technique is applied in the OFDM-RoF link to produce a pre-distorted Mach-Zehnder modulator input voltage. Simulation results showed important observations in terms of distortion-free dynamic range and Signal to Noise Ratio (SNR) for the applied offset biased predistortion technique
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Fungal endophytes from apple (Malus domestica) roots as biological control agents of apple replant disease
No full textWhen new young apple trees (Malus domestica) are planted in an orchard soil that was previously used to grow apples or related plant species, young trees can experience Apple Replant Disease (ARD). ARD results in root necrosis, reduction in plant growth and vigour, as well as reduced fruit yield and delayed fruit bearing, all of which harm growers’ return. Conventionally, chemical fumigants have been used to disinfect soil between plantings as a treatment for ARD, but the deregistration of harmful, chemical fumigants due to environmental and public health concerns has created a demand for eco-friendly alternative treatments. I explored fungal endophytes from healthy, mature apple roots as potential biocontrol agents to treat ARD and reduce the need for chemical fumigants.48 fungal endophytes were isolated from apple root and tested in dual culture competition assays for antagonistic activity against Pythium ultimum and Rhizoctonia solani; two pathogens associated with ARD. In dual culture competition assays, all endophytes were able to inhibit pathogens to some extent and different types of endophyte-pathogen interactions were observed. From the results of these assays, five biocontrol candidates were selected for further investigation, including two Trichoderma species, a Talaromyces sp., a Mortierella sp. and a Gongronella sp. The cell-free culture filtrates and extracts of these five biocontrol candidates were tested for antagonistic activity against ARD pathogens and for broad-spectrum antimicrobial activity. These five biocontrol candidates were also tested for phosphate solubilization ability, optimal growth temperature, fungicide tolerance, and initial growth promotion and anti-ARD trials were performed with apple rootstocks in the greenhouse.The cell-free culture filtrate from liquid cultures of five selected biocontrol endophytes demonstrated a range of inhibition potential against four ARD pathogens, with an endophyte identified as Mortierella NS-01 inhibiting all four pathogens to the greatest extent. We can infer that the antagonistic activity demonstrated in the dual culture assays of the isolates with antimicrobial culture filtrates was likely due to secreted non-volatile compounds and could occur independently of direct contact. Further studies could seek to identify specific antimicrobial molecules and test them in a similar assay. Conversely, ethyl acetate extracts did not generally support the results of the culture filtrate assays, perhaps due to antimicrobial molecules that were not extractable by ethyl acetate. Endophyte culture filtrates also demonstrated a range of inhibition against bacteria, yeast and fungi in liquid culture. Trichoderma isolates were tolerant to tested fungicides, whereas Talaromyces NS-01 showed sensitivity. Generally, the fungal endophytes grew optimally between 20-30℃. In vivo, inoculation of Talaromyces NS-01 and Mortierella NS-01 in combination resulted in a greater apple rootstock height in comparison to controls, indicating potential growth promoting effects. In ARD soil, there was generally not a statistically significant difference in size of inoculated apple plants compared to uninoculated after 8 weeks. Even so, in G202 rootstock, there tended to be an increase in size in inoculated plants in ARD soil, although the reverse was observed in M26 rootstock, and neither of these effects was statistically significant. Some of these inconsistencies could be addressed by developing a protocol that optimizes colonization of the apple roots.In conclusion, five biocontrol candidates were selected and particularly, Trichoderma NS-01, Trichoderma NS-02, Talaromyces NS-01 and Mortierella NS-01 inhibited ARD pathogens through secreted molecules. No clear conclusions were made on the potential for endophyte inoculations to work against ARD in vivo, although Talaromyces NS-01 and Mortierella NS-01 in combination have demonstrated growth promotion in non-ARD conditions.</p
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