127,091 research outputs found
Análise do impacto de pel decimation na codificação de vídeos de alta resolução
Full text linkDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Ciência da Computação, Florianópolis, 2014.Ao mesmo tempo em que o número de pixels por quadro tende a aumentar pela iminente adoção de resoluções ultra altas, a subamostragem de pixels, também conhecida por pel decimation, surge como uma opção viável para aumentar a eficiência energética da codificação de vídeo. Este trabalho investiga os impactos em energia e qualidade, quando pel decimation é aplicado ao cálculo da Soma das Diferenças Absolutas (SAD), a qual é a métrica de similaridade mais utilizada durante a etapa de estimação de movimento. Primeiramente, apresenta-se uma análise de qualidade de 15 padrões de subamostragem. Os 10.860 pontos experimentais usados proporcionam evidência estatística de que a razão de amostragem 4:3 proposta apresenta velocidade de codificação duas vezes maior do que a amostragem completa, perdendo apenas 5% em DSSIM e 1% em PSNR. A razão 4:3 apresenta o melhor custo-benefício entre aceleração e redução de qualidade, comparando-se com razões de menor amostragem. Para obter estimativas de área em silício e energia por bloco, cinco arquiteturas para cálculo da SAD foram projetadas e sintetizadas para uma biblioteca standard cell industrial. Dentre elas, uma pode ser configurada para operar com razões de amostragem 1:1, 4:3, 2:1 ou 4:1, ao passo que as demais foram projetadas para operar exclusivamente com cada uma destas razões de amostragem. A arquitetura configurável, operando em amostragem completa, consome 3,54 pJ/bloco (60% menos que a versão não-configurável), podendo ser reduzida até 1,34 pJ/bloco utilizando-se a razão de amostragem 4:1, com redução de 2,8% em PSNR e 14,1% em DSSIM. Finalmente, demonstra-se que a aceleração de codificação de um determinado padrão de subamostragem deve-se à redução conjunta do número de pixels amostradas e do número total de cálculos de SAD. Assim, modelando-se as componentes de energia da codificação de vídeos, demonstra-se que a eficiência energética do processo de codificação como um todo pode ser melhorada além da razão de subamostragem. Utilizando-se uma arquitetura de SAD configurável, a economia de energia pode ser de até 95,11%.Abstract : As the number of pixels per frame tends to increase by the upcoming adoption of ultra high resolutions, pixel subsampling, also known as pel decimation, appears as a viable means to improve the energy efficiency of video coding. This work investigates the impacts on energy and quality when pel decimation is applied to the Sum of Absolute Differences (SAD) calculation, which is the most used similarity metric in motion estimation step of video coding. Firstly, a quality assessment of 15 pel decimation patterns is presented. The 10,680 experimental points used provide statistical evidence that the proposed 4:3 ratio leads to an encoding speedup of more than two times in comparison to full sampling, losing only 5% in DSSIM and 1% in PSNR. Compared with lower sampling ratios, it presents a better trade-off between speedup and quality loss. To obtain estimates for silicon area and energy per block, five SAD architectures were designed and synthesized for an industrial standard cell library. Among those, one can be configured to operate with 1:1, 4:3, 2:1 or 4:1 sampling ratios, whereas the rest are tailored to operate exclusively with each one of these ratios. The configurable architecture consumes 3.54pJ/block operating in full sampling (60% lower than the nonconfigurable). The energy can be further reduced until 1.34pJ/block by using 4:1 ratio, with losses of 2.8% in PSNR and 14.1% in DSSIM. Finally, it is shown that the speedup of a given subsampling pattern is due the reduction of both the number of sampled pixels and the total number of SAD calculations. Therefore, by modeling the video coding energy components, it is shown that the whole video compression energy efficiency can be increased beyond the sampling ratio. By using a configurable SAD architecture operating in 4:1 ratio the energy savings are up to 95:11%
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
L'altruisme és la raó principal per decantar-se pel comerç just
Full text linkEl capitalisme com a sistema econòmic, que també té profundes implicacions filosòfiques, integra moltes formes d'inversió i de comerç, entre les quals destaquen cada vegada més les inversions socialment responsables i el comerç just. Segons l'Institut per a la Inversió de Morgan Stanley, el 85% dels inversors estan interessats en inversions sostenibles, i el 67% dels inversors de la generació mil·lennial participen com a mínim en una activitat d'inversió sostenible i tenen gairebé el doble de probabilitats d'invertir en empreses o fons que estableixen com a objectiu resultats socials o ambientals específics. Pel que fa al comerç just, una enquesta esmentada en un informe publicat per l'Agència Catalana del Consum assenyala que el 72% dels enquestats estan disposats a comprar un producte que faci un patrocini vinculat a alguna causa solidària. Què porta tantes persones a apostar per aquest model econòmic? Segons diversos estudis fets en l'última dècada, en la decisió de fer inversions socialment responsables o d'adquirir productes de comerç just hi intervenen tant factors econòmics com la percepció que a la llarga s'obtindran més beneficis, a més de factors no econòmics. Destaquen la bona reputació i l'aprovació social que comporta decantar-se explícitament per aquest model, la sensació de benestar que comporta saber que s'està contribuint a una causa solidària que coincideix amb la visió ètica de cadascú i, per descomptat, l'altruisme, que és molt propi de l'espècie humana. La investigadora Xiaolan Yang i els seus col·laboradors, del Laboratori de Ciències Cognitives de la Universitat Internacional de Shanghai i de la Facultat d'Economia de la Universitat de Zhejiang, a la Xina, han examinat fins a quin punt l'altruisme té influència quan prenem la decisió de fer una inversió socialment responsable o d'adquirir productes de comerç just. Els resultats del treball, publicats a la revista Frontiers in Neuroscience, indiquen que un dels factors importants a tenir en compte per estimular els inversors a fer inversions socialment responsables i els ciutadans a decantar-se pel comerç just és el mirament pel bé de les altres persones, és a dir, l'altruisme
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
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
Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
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
Sarah L. Blum Author Visit - Warrior Nurse: PTSD and Healing
No full textHear Sarah L. Blum, author of Women Under Fire: Abuse in the Military, discuss her newest book, Warrior Nurse: PTSD and Healing followed by a Q&A and book signing.
Sarah L. Blum is a decorated Vietnam veteran who served as an operating room nurse during the intense fighting of 1967. In recognition of her service, she was awarded the Army Commendation Medal.
Sponsored by CWU Veterans Center and CWU Libraries.https://digitalcommons.cwu.edu/libraryevents/1252/thumbnail.jp
Analysis of whole/untreated biological samples using direct thermal desorption combined with gas chromatography
Full text linkIrth, H. [Promotor]Vreuls, J.J. [Copromotor]Pel, R. [Copromotor
Recorregut de recerca geològica i mineralògica pels departaments de l´Aude (Pais d´Atsat / Axat) i de l´Arieja / Ariège (pel pais de Fois / Foix): des d´Espesèlh / Espezel a Comuns / Comus, Gorges De L´Afrau i a Belesta
No full textRecorregut realitzat el 7 de juliol del 2014. El recorregut del present itinerari, es desenvoluparà íntegrament pel Sistema Pirinenc; distribuint en la seva totalitat part per la Zona Nord – Pirinenca. Tot i així, alguns recorreguts es faran molt prop de la Zona Axial del Sistema Pirinenc, però en cap moment arribarem a tallar aquesta unitat. Així, el recorregut començarà dintre de la primera unitat, (dintre de l´antigament anomenat Prepirineu Septentrional), per la qual es circularà al llarg de tot el recorregut de l´itinerari, que començarem a Espesèlh / Espezel. Després seguint sempre per aquesta unitat geològica, ens aproparem a la població de Comus i a les Gorges de l´Afrau, per anar després cap a Belesta, per on finalitzarà aquest recorregut. Per d´altra banda, la pràctica totalitat del recorregut es realitzarà pel Departament de l´Ariège (pel País de Fois). Una altra part del recorregut es farà pel Departament de l´Aude (pel País d´Atsat / Axat)
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