2,105 research outputs found
Temporal video transcoding from H.264/AVC-to-SVC for digital TV broadcasting
Mobile digital TV environments demand flexible video compression like scalable video coding (SVC) because of varying bandwidths and devices. Since existing infrastructures highly rely on H.264/AVC video compression, network providers could adapt the current H.264/AVC encoded video to SVC. This adaptation needs to be done efficiently to reduce processing power and operational cost. This paper proposes two techniques to convert an H.264/AVC bitstream in Baseline (P-pictures based) and Main Profile (B-pictures based) without scalability to a scalable bitstream with temporal scalability as part of a framework for low-complexity video adaptation for digital TV broadcasting. Our approaches are based on accelerating the interprediction, focusing on reducing the coding complexity of mode decision and motion estimation tasks of the encoder stage by using information available after the H. 264/AVC decoding stage. The results show that when our techniques are applied, the complexity is reduced by 98 % while maintaining coding efficiency
On the impact of video stalling and video quality in the case of camera switching during adaptive streaming of sports content
The widespread usage of second screens, in combination with mobile video streaming technologies like HTTP Adaptive Streaming (HAS), enable new means for taking end-users' Quality of Experience (QoE) to the next level. For sports events, these technological evolutions can, for example, enhance the overall engagement of remote fans or give them more control over the content. In this paper, we consider the case of adaptively streaming multi-camera sports content to tablet devices, enabling the end-user to dynamically switch cameras. Our goal is to subjectively evaluate the trade-off between video stalling duration (as a result of requesting another camera feed) and initial video quality of the new feed. Our results show that short video stallings do not significantly influence overall quality ratings, that quality perception is highly influenced by the video quality at the moment of camera switching and that large quality fluctuations should be avoided
Financial phantasmagoria: corporate image-work in times of crisis
Our purpose in this article is to relate the real movements in the economy during 2008 to the ?image-work? of financial institutions. Over the period January?December 2008 we collected 241 separate advertisements from 61 financial institutions published in the Financial Times. Reading across the ensemble of advertisements for themes and evocative images provides an impression of the financial imaginaries created by these organizations as the global financial crisis unfolded. In using the term ?phantasmagoria? we move beyond its colloquial sense of a set of strange images designed to dazzle towards the more technical connotation used by Ranci�re (2004) who suggested that words and images can offer a trace of an overall determining set-up if they are torn from their obviousness so they become phantasmagoric figures. The key phantasmagoric figure we identify here is that of the financial institution as timeless, immortal and unchanging; a coherent and autonomous entity amongst other actors. This notion of uniqueness belies the commonality of thinking which precipitated the global financial crisis as well as the limited capacity for control of financial institutions in relation to market events. It also functions as a powerful naturalizing force, making it hard to question certain aspects of the recent period of ?capitalism in crisis?
Giraffe translocation population viability analysis
Most populations of giraffes have declined in recent decades, leading to the recent IUCN decision to upgrade the species to Vulnerable status, and some subspecies to Endangered. Translocations have been used as a conservation tool to re-introduce giraffes to previously occupied areas or establish new populations, but guidelines for founding populations are lacking. To provide general guidelines for translocation projects regarding feasibility, we simulated various scenarios of translocated giraffe populations to identify viable age and sex distributions of founding populations using population viability analysis (PVA) implemented in Vortex software. We explored the parameter space for demography and the genetic load, examining how variation in founding numbers and sex ratios affected 100 yr probability of population extinction and genetic diversity. We found that even very small numbers of founders (N ≤ 10 females) can appear to be successful in the first decades due to transient positive population growth, but with moderate population growth rate and moderate genetic load, long-term population viability (probability of extinction 95% genetic diversity of the source population in an isolated population, 50 females and 5 males are recommended to compose the founding population. Sensitivity analyses revealed first-year survival and reproductive rate were the simulation parameters with the greatest proportional influence on probability of extinction and genetic diversity. These simulations highlight important considerations for translocation success and data gaps including true genetic load in wild giraffe populations
La planta ideal de yuca para obtener rendimientos máximos
A series of trials were carried out using cassava. Crop growth rate increased with leaf area up to LAI 4; root growth rate increased up to LAI 3-3.5, then declined. LAI is determined by leaf size, leaf formation rate and individual leaf life. Leaf size reached a max 4 mo after planting and then decreased; the max was a varietal character. Leaf life was reduced by shading but in full daylight was determined by the var. Leaf formation rate/shoot apex showed little genetic vafiation and declined with time; large differences in leaf formation rate/plant were determined by differences in branching pattern. Top growth had preference over root growth, and root sink was not limiting when root no./plant was equal to or greater than 9. A computer program was written to implement a dynamic growth model, which suggests that high-yielding plants will branch late in life and possess large leaves and long leaf life. Potential yields of greater than 25 t/ha/yr dry roots are obtainable at 400-500 g cal (cm)-2 day radiation. (AS
PUK35 Time Savings with Once-Monthly C.E.R.A.: A Time and Motion Study Conducted in 13 Hemodialysis Centres in Italy
Subspecialty preferences among Neurologists of the future.
INTRODUCTION: In the era of neurological subspecialization, most neurologists will have a field of specialist interest. The aim of this cross-sectional multi-national study was to identify the key areas of interest among trainees or junior specialists, assess the potential influence of an interest in research, and consider the results in light of population needs. METHODS: A total of 300 residents and junior neurologists who received a bursary to attend the European Academy of Neurology conference were invited to participate in this study. Demographic and work-related characteristics, as well as main subspecialty of choice were examined via an anonymous electronic questionnaire. Participants holding a higher degree (PhD/MD) or working in research posts were considered research oriented. RESULTS: In total, 191 Neurologists in training or junior specialists responded (response rate 63.7%). Full data were available for 187 participants (59.4% females). The study sample had a mean age of 30.5±3.4 years (range 25 - 45). The most popular subspecialty was movement disorders (18.2%), followed by multiple sclerosis (11.2%) and epilepsy (10.2%). This did not differ significantly between the participants who were or were not research-oriented. CONCLUSIONS: There is a potential mismatch between the interests of trainees, and the future needs of the populations they serve, which it is important to identify for workforce planning
Indigenous species of Crataegus (Rosaceae-Maloideae) in Flanders (Belgium): an explorative morphometric study
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