1,721,022 research outputs found
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
Development of Reconfigurable Circuits for WPAN Applications
No full textThis thesis presents the development of a low-power analog-to-digital converter (ADC) which is intended to be used in WPAN receivers. WPAN devices are usually mobile and, therefore, operate on batteries. This puts a strict limitation on the power dissipation of WPAN systems. One common problem in WPAN systems is the overspecification problem. The receiver, which has to satisfy the requirements under demanding conditions, operates as overspecified when the conditions are not demanding. This reduces the power efficiency of WPAN systems. Other problems of WPANs include market segmentation and high design margins due to process variations. All these problems result in reduced power efficiency. In this project, adaptive reconfiguration concept is proposed. Adaptive reconfigurability concept is based on the idea that environment-aware systems can prevent the power inefficiencies by reconfiguring themselves to the desired level of performance. Moreover, in this thesis, best alternative selection method which is a statistical mismatch compensation method is proposed. This method aims to eliminate the high area and power cost of the conventional mismatch compensation techniques. In order to demonstrate the proposed techniques, a low-power, 25 MS/s SAR ADC which is reconfigurable between 5-12 bits is designed. It utilizes best alternative selection method for mismatch compensation in its DAC array and comparator. Simulation results show that the analog power dissipation of the ADC can be scaled efficiently which verifies the reconfiguration concept. The designed ADC is fabricated in TSMC 65 nm standard CMOS. It occupies a silicon area of 997.8 μm X 2040 μm. Operational tests show that the ADC functions properly. The comparator offset whose simulated RMS value is 14.6 mV and whose RMS value for 64 tested comparators is 19.83 mV is brought to only 0.29 mV as a result of calibration. This is a result which proves the power of best alternative selection methods. The DAC array could not yet be calibrated since its calibration will take more time than expected because of the noise floor which is 12.5 dB higher than its expected value during the design phase
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
Power-Efficient Pipelined Analog-to-Digital Converter Architectures for Advanced CMOS Technologies
No full textAmong different analog-to-digital converter (ADC) architectures pipelined ADCs are the most suited for medium sampling frequencies (50-300MSPS) and medium resolutions, i.e. 8 to 14 bits. Having the lowest figure-of-merit (FOM) in its bandwidth and resolution category, this architecture is frequently used for high-bandwidth software-defined radio applications. However, due to the continuous down-scaling trends, designing low-power pipelined ADCs becomes extremely difficult as supply voltages diminish and characteristics of CMOS devices deteriorate (e.g., low intrinsic gain). This thesis addresses these issues in three points: Proposes an analogue technique relaxing the constraints on multiplying D/A converter (MDAC) stages due to low supply voltage and low intrinsic gain, Introduces a power-efficient architecture, Presents an optimization method for exploiting the performance fully. A system-level methodology is developed to investigate different architectural possibilities and to find the one with the lowest power consumption. The architecture of pipelined converters is generalized for fractional gains and analyzed systematically; an optimization toolkit which uses the derived system-level models is developed in MATLAB. Using this approach, this work shows that the power dissipation can be decreased more than 20% with slight modification of inter-stage gains by using general integer and fractional MDACs depending on resolution, operation frequency, and analog blocks. For relaxing the constraints on amplifiers, an MDAC stage incorporating a novel technique for compensating the residual error due to finite amplifier gain is proposed. With this technique, it is shown that high speed and high resolution pipelined ADCs can be designed using simple low-gain amplifiers without gain-boosting. Similar techniques in the literature like time-shifted correlated double sampling (TS-CDS) and time-aligned CDS (TA-CDS) are based on a hold capacitor for storing and subtracting the residual error. This work demonstrates that the selection of the hold capacitance in these techniques has a significant impact on the total power, as much as 46% for individual MDACs. A system-level analysis of TS/TA-CDS stages has been presented and optimal scaling of hold capacitors is demonstrated on example pipeline architectures
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
Design of wideband high-resolution low-pass continuous-time delta-sigma modulators in CMOS process
No full textLe marché des convertisseurs analogique-numérique peut être segmenté en deux catégories de circuits. Nous distinguons d’une part, les blocs de propriété intellectuelle (IP) qui sont généralement optimisés pour une application spécifique. Et d’autre part, les circuits intégrés discrets qui sont conçus pour répondre aux besoins d’une plus large gamme d’applications. Ce travail de thèse concerne la deuxième catégorie de composants. Il s’inscrit dans le cadre d'un programme de recherche et développement initié en 2010 dans le projet européen FP7 SACRA et dont le but était d'étudier la faisabilité d'un convertisseur analogique-numérique Delta-Sigma (DS) qui pourrait rivaliser avec l'architecture pipeline pour des applications nécessitant une large bande passante (≥10MHz) et une haute résolution (>10-bit) comme l’imagerie médicale, les communications numériques sans fils ou câblées, la vidéo ou encore l’instrumentation. Ce manuscrit synthétise les travaux de conception, fabrication et mesure d’un modulateur DS Passe-bas à temps continu avec une bande passante de 40MHz, et visant une résolution effective de 12-bit tout en consommant moins de 100mW.The market of A/D converters can be segmented in two categories. From one side we distinguish the Intellectual Property (IP) blocks that are generally optimized for a specific application. On the other side, the general-purpose discrete Integrated Circuits (ICs) that are designed such as they could be used in different applications. This thesis work deals with the second category. It is part of a research and development program initiated in 2010 in the European project FP7 SACRA, whose purpose was to study the feasibility of a delta-sigma (DS) analog-to-digital converter that could compete with the pipeline architecture for applications that require high bandwidth (≥10MHz) and high resolution (>10-bit) such as medical imaging, wireless and wireline communications, video or instrumentation. Currently, the pipeline is still largely predominant for such applications and the few commercial wideband solutions based on a DS architecture have a signal bandwidth limited to 10 MHz or 25 MHz while consuming respectively 100mW and 20mW for an ENOB around 12-bit. This manuscript summarizes the design, fabrication and measurement of a low-pass CT DS modulator with a signal bandwidth of 40MHz, while targeting an effective resolution of 12-bit and a power consumption of less than 100mW
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