1,720,978 research outputs found
Miglioramenti costruttivi e di pilotaggio di un display a gradazione a cristallo liquido ferroelettric
No full textWe describe the improvement of a fabrication solution for a ferroelectric liquid crystal display. Moreover a novel addressing technique is employed to drive the display at video rate by using voltages compatible with commercial circuitry.We describe the improvement of a fabrication solution for a ferroelectric liquid crystal display. Moreover a novel addressing technique is employed to drive the display at video rate by using voltages compatible with commercial circuitry
A novel machine to deposit thin PTFE films for LC alignment
No full textA novel dust-free machine is presented for single step deposition of oriented PTFE and other polymer films, suitable as alignment jayers in LC displays. Deposition conditions can be adjusted to optimize the alignment capabilities of the film. Films are more thin, uniform nd oriented than those obtained by spinning and rubbing
Passive matrix SSFLC display with analogue grey levels using PTFE alignment films
No full textFabrication and performance of a surface stabilised ferroelectric liquid crystal display are reported. Grey shades are obtained by modulating the width of switched FLC microdomains by means of an electric field gradient distributed over the pixel, between adjacent metal columns. Such a gradient, depending on the data voltages, is achieved through a high resistance film deposited on the column glass plate. The choice of PTFE (Poly-tetra-fluoro-ethylene) alignment layers, easily deposited by friction, provides very low hysteresis and sticking effect. Morphology of alignment layers, carried out by AFM, is briefly described and evaluated. Addressing mode voltage waveforms to obtain grey shades are also reported. (C) 1999 Elsevier Science B.V. All rights reserved
Dispositivi elettroottici a cristallo liquido ferroelettrico
No full textA discussion on the basic working principles of ferroelectric liquid crystal devices is presented. The most recent advances in fabrication technology and design rules for addressing ferroelectric liquid crystal flat panel matrix displays will be reported. Moreover novel applications such as photonic devices will be mentioned
Video speed low total voltage matrix addressing technique for SSFLC displays
No full textNovel computed and experimental results are achieved with addressing modes capable of video rate speed with equal selection and data voltages and a commercially available FLC mixtures. Total voltage requirements for integrated circuit drivers is strongly reduced and is now made compatible with existing STN driver technology. A new automatic fit procedure, necessary for fast evaluation of cell parameter and subsequent simulation of cell behavior under matrix addressing, is also described
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
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