191 research outputs found
COLLADA + MPEG-4 or X3D + MPEG-4
The paper is an overview of 3D graphics assets and applications standards.The authors analyzed the three main open standards dealing with three-dimensional (3-D) graphics content and applications, X3D, COLLADA, and MPEG4, to clarify the role of each with respect to the following criteria: ability to describe only the graphics assets in a synthetic 3-D scene or also its behavior as an application, compression capacities, and appropriateness for authoring, transmission, and publishing. COLLADA could become the interchange format for authoring tools; MPEG4 on top of it (as specified in MPEG-4 Part 25), the publishing format for graphics assets; and X3D, the standard for interactive applications, enriched by MPEG-4 compression in the case of online ones. The authors also mentioned that in order to build a mobile application, a developer has to consider different hardware configurations and performances, different operating systems, different screen sizes, and input controls
One-Cycle Pruning: Pruning ConvNets Under a Tight Training Budget
Introducing sparsity in a neural network has been an efficient way to reduce
its complexity while keeping its performance almost intact. Most of the time,
sparsity is introduced using a three-stage pipeline: 1) train the model to
convergence, 2) prune the model according to some criterion, 3) fine-tune the
pruned model to recover performance. The last two steps are often performed
iteratively, leading to reasonable results but also to a time-consuming and
complex process. In our work, we propose to get rid of the first step of the
pipeline and to combine the two other steps in a single pruning-training cycle,
allowing the model to jointly learn for the optimal weights while being pruned.
We do this by introducing a novel pruning schedule, named One-Cycle Pruning,
which starts pruning from the beginning of the training, and until its very
end. Adopting such a schedule not only leads to better performing pruned models
but also drastically reduces the training budget required to prune a model.
Experiments are conducted on a variety of architectures (VGG-16 and ResNet-18)
and datasets (CIFAR-10, CIFAR-100 and Caltech-101), and for relatively high
sparsity values (80%, 90%, 95% of weights removed). Our results show that
One-Cycle Pruning consistently outperforms commonly used pruning schedules such
as One-Shot Pruning, Iterative Pruning and Automated Gradual Pruning, on a
fixed training budget.Comment: Accepted at Sparsity in Neural Networks (SNN 2021
A model for adapting 3D graphics based on scalable coding, real-time simplification and remote rendering
Most current multiplayer 3D games can only be played on dedicated platforms, requiring specifically designed content and communication over a predefined network. To overcome these limitations, the OLGA (On-Line GAming) consortium has devised a framework to develop distributive, multiplayer 3D games. Scalability at the level of content, platforms and networks is exploited to achieve the best trade-offs between complexity and quality
HANDLING MULTILINGUAL CONTENT IN DIGITAL MEDIA: A CRITICAL ANALYSIS
This document expresses and analyzes the need to define a generic method for representing multilingual information in multimedia data. It describes the basic requirements that would bear upon such representations and establishes the potential link with ISO committee TC 37/SC 4 (Language Resource Management) and with XMT (eXtended MPEG-4 Textual format)
Preclinical Testing of Living Tissue-Engineered Heart Valves for Pediatric Patients, Challenges and Opportunities
Introduction: Pediatric patients with cardiac congenital diseases require heart valve implants that can grow with their natural somatic increase in size. Current artificial valves perform poorly in children and cannot grow; thus, living-tissue-engineered valves capable of sustaining matrix homeostasis could overcome the current drawbacks of artificial prostheses and minimize the need for repeat surgeries. Materials and Methods: To prepare living-tissue-engineered valves, we produced completely acellular ovine pulmonary valves by perfusion. We then collected autologous adipose tissue, isolated stem cells, and differentiated them into fibroblasts and separately into endothelial cells. We seeded the fibroblasts in the cusp interstitium and onto the root adventitia and the endothelial cells inside the lumen, conditioned the living valves in dedicated pulmonary heart valve bioreactors, and pursued orthotopic implantation of autologous cell-seeded valves with 6 months follow-up. Unseeded valves served as controls. Results: Perfusion decellularization yielded acellular pulmonary valves that were stable, no degradable in vivo, cell friendly and biocompatible, had excellent hemodynamics, were not immunogenic or inflammatory, non thrombogenic, did not calcify in juvenile sheep, and served as substrates for cell repopulation. Autologous adipose-derived stem cells were easy to isolate and differentiate into fibroblasts and endothelial-like cells. Cell-seeded valves exhibited preserved viability after progressive bioreactor conditioning and functioned well in vivo for 6 months. At explantation, the implants and anastomoses were intact, and the valve root was well integrated into host tissues; valve leaflets were unchanged in size, non fibrotic, supple, and functional. Numerous cells positive for a-smooth muscle cell actin were found mostly in the sinus, base, and the fibrosa of the leaflets, and most surfaces were covered by endothelial cells, indicating a strong potential for repopulation of the scaffold. Conclusions: Tissue-engineered living valves can be generated in vitro using the approach described here. The technology is not trivial and can provide numerous challenges and opportunities, which are discussed in detail in this paper. Overall, we concluded that cell seeding did not negatively affect tissue-engineered heart valve (TEHV) performance as they exhibited as good hemodynamic performance as acellular valves in this model. Further understanding of cell fate after implantation and the timeline of repopulation of acellular scaffolds will help us evaluate the translational potential of this technology
Periodontitis and Heart Disease: Current Perspectives on the Associative Relationships and Preventive Impact
Due to the important advancement and the accumulation of new evidence on the periodontitis-cardiovascular disease (CVD) relationship as well as the major medical, economic and social burden caused by both diseases this chapter aims to review existing epidemiological and pathogenetic links related to this topic. Also, this chapter aims to highlight the impact of the periodontitis-CVD relationships on clinical practice and on the preventive approaches targeting to decrease the impact of periodontitis on CVD. Periodontitis is an infectious disease eliciting local and general inflammation, which leads to periodontal destruction and systemic involvement. Several pathways could explain the link between periodontitis and CVD such as bacteraemia, chronic persistent systemic inflammation and oxidative stress. The first step in the treatment of periodontitis addresses the elimination of microbial components, which lead to a decrease in local and systemic inflammation. Periodontal therapy seems to positively impact CVD. Specialists should inform patients with CVD on the negative impact of periodontitis on their systemic status and refer patients to the periodontist for an extensive examination as routine management of CVD. Some possible risks of periodontal therapy should be considered in patients undergoing antithrombotic medication
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