1,720,961 research outputs found
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
A Retrospective Audit Of Biojet® Prostate Fusion Biopsies Amongst Patients Seen In A High-Volume Private Referral Centre In Cape Town Between January 2017 And April 2020
Full text linkIntroduction: The field of prostate cancer has seen a dramatic change in its approach to diagnosis, from the advent of PSA in the 1980s to the transrectal ultrasound guided 12 core biopsies with a false negative rate of approximately 30%. Recent advances in this field involve fusing MRI images with real-time ultrasound images to guide the surgeon. The aim of the study was to evaluate the performance of Biojet® prostate fusion biopsy system in a high-volume private referral centre. Methods: Retrospective observational audit of men who presented to a private urology practice in Cape Town for Biojet® prostate fusion biopsy based on clinical suspicion for prostate cancer. Data were collected as per the recommendations of the Standards of Reporting for MRI-targeted Biopsy Studies (START) of the Prostate group and anonymously entered onto a Redcap database. Results: The median age of the patient population was 64 (SD 9.124) years. The median PSA level was 6.5 ng/ml (IQR- 4.7). Most patients (78/135) had a clinical stage of T1c (57%). In the biopsy naïve group, a total of 103 PIRADS lesions were identified. Amongst the PIRADS 3 lesions 15/28 lesions (53%) had a positive cancer diagnosis. Of the PIRADS 4 lesions 37/60 lesions (62%) had a positive cancer diagnosis and in the PIRADS 5 group 13/15 lesions (87%) had a positive cancer diagnosis. 21 of the 42 men (50%) with a previous negative prostate biopsy had a positive cancer diagnosis using the Biojet® prostate fusion biopsy. Conclusion: In this study the Biojet® prostate fusion biopsy performed similar to other international studies however the pickup rate of cancer in those who had a previous negative biopsy was higher than those seen in the other global studies
Development and implementation of high performance and high efficiency interior permanent magnet synchronous motor drive
No full textAs the motor consumes more than 50% of total electrical energy produced in the world, the efficiency optimization of the motor is a burning issue in terms of saving energy and the environment. In modern days researchers display immense interest in the control of a high performing interior permanent magnet synchronous motors (IPMSM) drive for general industrial applications. The IPMSM is largely used in low and medium power applications such as adjustable speed drives, robotics, aerospace and electric vehicles due to its several advantageous features such as high power density, greater flux weakening capability, high output torque, high power factor, low noise, robustness and high efficiency as compared to the dc motors and induction motors (IM). Nevertheless, its high efficiency characteristics are influenced by applied control strategies. Most of the reported works developed control algorithms for IPMSM to achieve high performance. However, the efficiency optimization of IPMSM, which is one of the important aspects is often ignored. Therefore, in this thesis the efficiency optimization issues is also considered along with high performance control. This thesis presents a nonlinear loss model-based controller (LMC) for IPMSM drive to achieve both high efficiency and high performance of the drive. Among numerous loss minimization algorithms (LMA), a LMC approach offers a fast response without torque pulsations. However, it requires the accurate loss model and the knowledge of the motor parameters. Therefore, a difficulty in deriving the LMC lies in the complexity of the full loss model. Moreover, the conventional LMC does not pay attention to the performance of the drive at all. In an effort to overcome the drawbacks of conventional LMC, an adaptive backstepping based nonlinear control (ABNC) is designed to achieve high dynamic performance speed control for an IPMSM drive is developed in this thesis. The system parameter variations as well as field control are taken into account at the design stage of the controller. Thus, the proposed ABNC is capable of maintaining the system robustness and stability against mechanical parameter variation and external load torque disturbance. To ensure stability the controller is designed based on Lyapunov’s stability theory while the LMC ensures high efficiency of the drive. A neuro-fuzzy logic controller (NFC) including LMC is also developed in this work. The proposed NFC overcomes the unknown and nonlinear uncertainties of the drive, the membership function of the controller is tuned online. An important part of this work is directed to develop an adaptive network-based fuzzy inference system (ANFIS) based NFC. In this work, an adaptive tuning algorithm is also developed to adjust the membership function and consequent parameters. The complete closed-loop system model is developed and then simulated using MATLAB/Simulink software. Performance of the various control algorithms based IPMSM drive is investigated extensively at different dynamic operating conditions such as sudden load change, command speed change, parameter variation, etc. The performance of the proposed loss minimization based ABNC and NFC are also compared with the conventional id=0 control scheme. The complete IPMSM drive have been successfully implemented in real-time using digital signal processor (DSP) controller board DS1104 for a laboratory 5 hp motor. The experimental results verify the simulation of NFC based loss minimization. It is found from the results that proposed drive algorithms can improve the efficiency by around 3% as compared to without any LMA
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
Scratch and mar behavior of textured polymeric surfaces
No full textSurface damages such as scratch and mar can significantly affect the aesthetics of polymeric surfaces. The study of scratch and mar behavior of polymers can be more challenging if the polymeric surfaces are textured. Scratch and mar can be easily viewed if the surface is smooth whereas surface texture may hide the scratches. Recently, putting texture on polymeric surfaces has shown to improve scratch visibility resistance; however, it exposes polymers to a new form of surface damages. The intention of this research is to examine the impact of putting textures on scratch and mar visibility of polymeric surfaces through analysis of the deformation, and development of stress-strain field during scratching. Three-dimensional finite element method (FEM) modeling using ABAQUS were performed to study the mechanism associated with the scratch and mar damages incurred in textured surfaces. Results suggest that, for a sharper tip, increase in surface roughness distributes the normal load over a smaller number of asperities that results in to the local plastic deformation and different texture pattern can easily mask these kinds of damage and improve scratch visibility resistance. However, when scratching is done with blunter tips, due to compressed ironing, texture surface gets smoother after scratching which makes scratches more visible
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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