1,720,970 research outputs found
Robust multiple-initial-point prediction algorithm for fast motion estimation in the MPEG-2 standard
No full textWe present a novel, computationally efficient and robust scheme for multiple-initial-point predictors used in fast searches in the MPEG-2 standard. Extensive testing in a variety of video sequences with different motion characteristics clearly shows that it outperforms the center- and median-based predictors currently used by mean square error (MSE) reduction of 1.51, 5.25, and 3.62% for the diamond, the three-step, and the four-step searches and for the same bit rates as the standard
Speeding up the optimization of the rate distortion performance in MPEG-2 video coding through quantizer loop parameterization
No full textA simple scheme for fast Rate Distortion optimization based on Lagrange multipliers is presented in this paper. It is based on the observation that for accurate target rates, the change of the multiplier alone may not have an effect for small step sizes. However, a combination of small step sizes alogn with appropriate quantizer loop parameterization may solve this problem thus result in in significant computaiotnal savings since only a portion of the Rate distortion characteristics need to be considered for optimization. Extensive experiments using quantizer loop parameterization reveal savings between 60.14 and 92.94% for the rate bounding case and between 56.48 and 91.01% for the bisection search for a wide variety of video sequences exhibiting different characteristics
Optimizing motion estimation in MPEG-2 standard
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Implementation of sinusoidal pulse width modulation based on cordic algorithm using silterra 0.18µm CMOS technology: article
Full text linkThis thesis presents the implementation of Sinusoidal Pulse Width Modulation (SPWM) using Silterra 0.18µm technology and it is based on CORDIC algorithm. The SPWM technique is used to control switches such as Insulated Gate Bipolar Transistor (IGBT) in major AC appliances. Synopsys tool is used to synthesize the Verilog Hardware Description language (HDL) model of the SPWM to its ASIC form. The use of Coordinate Rotation Digital Computer (CORDIC) in the source code make it provides an area-efficient architecture for effective design at Silterra 0.18µm CMOS technology
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
Three novel low complexity scanning orders for MPEG-2 full search motion estimation
No full textComplexity localisation in the reference frame is the key process for the derivation of efficient scanning orders for motion estimation. The more localised the complexity is, the more computationally efficient scanning orders can be derived for reduced cost motion estimation algorithms. However, this processes entails serious pre-processing overhead which may render it unsuitable for real time video coding systems. In this paper, we propose three low complexity scanning orders of similar performance that are very competitive in terms of the operation count ratio metric with respect to the MPEG-2 raster scan order, show improvements of 7.14% on the average with respect to the number of examined macroblock rows metric and they also show an increase in the speed-up ratio of 0.12 on the average as compared to the standard. As compared to other work in the literature, the proposed scanning orders require one fourth of the operation count ratio and show an increase in the speed-up ratio of 45 times on the average
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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