1,720,968 research outputs found
Performance Analysis of Fast Closed-Loop Power Control For WCDMA Systems
No full textIn this thesis project, the author has carried out a thorough study on the performance of an uplink wideband CDMA (WCDMA) cellular system under fast closed-loop power control. Two study approaches are taken. Firstly, analytical study is carried out over a simplified cellular system. A mathematical model for the received signal power is proposed in terms of the probability density function. A large number of important parameters affecting the system performance have been included. The parameters taken into account include Doppler frequency which is related to mobile station's velocity , number of resolvable multipaths , maximum allowable transmitted power, power control updating frequency , number of pilot symbols per transmission frame, and number of receive diversity antenna branches. A set of analytical expression is then derived for the evaluation of the system performance in terms of bit-error rate (BER). The proposed analytical analysis approach has been verified to give good prediction of the system BER performance through comparison with simulation. The mathematical expression derived allow quick analysis of how various parameters may effect the WCDMA system performance. Next, simulation approach is adopted where most of the assumptions made in the pervious analyses are relaxed. A number of parameters are not taken into account in analytical method, such as number of power control command bits, power adjustment step-size, feedback channel error rate, type of power estimator, and power adjustment step-size control logic due to mathematical complexity. With simulation approach, the study of these parameters can be carried out. The analytical expression derived earlier have helped to serve as a reference for calibrating the simulation program developed.
A new method for estimating the received signal power based on Minimum Mean Square Error (MMSE) criteria is then proposed and is found to outperform the conventional power estimator at high mobile speed. Performance and characteristics of the conventional fixed step-size power control scheme has been examined and optimum step-sizes have been identified. A simple adaptive power adjustment step-size control based on information of current and past power control commands is found to be able to improve system performance at low mobile speed. Another adaptive power adjustment step-size control scheme, which takes into account information of the received signal-to-interference ratio (SIR), mobile speed and effective number of resolvable multipaths, has been shown to perform optimally over a wide range of channel conditions
Closed-loop power control algorithms for cellular mobile CDMA systems
No full textIn this thesis, the author carried out a thorough study on the performance of a reverse link DS/CDMA system with various fast closed-loop power control algorithms. The algorithms studied include the Conventional single and multiple step-size, and two newly proposed alternatives, i.e., Adaptive step-size, and Predictive power control algorithms. Major parameters affecting the system performance were identified. The relationships between each of these parameters and system performance were examined. Finally, the optimum values for control variables associated with each power control algorithm were obtained or recommended.Master of Engineerin
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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