2,753 research outputs found

    GPU-Based Volume Rendering of Noisy Multi-Spectral Astronomical Data

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    Traditional analysis techniques may not be sufficient for astronomers to make the best use of the data sets that current and future instruments, such as the Square Kilometre Array and its Pathfinders, will produce. By utilizing the incredible pattern-recognition ability of the human mind, scientific visualization provides an excellent opportunity for astronomers to gain valuable new insight and understanding of their data, particularly when used interactively in 3D. The goal of our work is to establish the feasibility of a real-time 3D monitoring system for data going into the Australian SKA Pathfinder archive. Based on CUDA, an increasingly popular development tool, our work utilizes the massively parallel architecture of modern graphics processing units (GPUs) to provide astronomers with an interactive 3D volume rendering for multi-spectral data sets. Unlike other approaches, we are targeting real time interactive visualization of datasets larger than GPU memory while giving special attention to data with low signal to noise ratio - two critical aspects for astronomy that are missing from most existing scientific visualization software packages. Our framework enables the astronomer to interact with the geometrical representation of the data, and to control the volume rendering process to generate a better representation of their datasets.Comment: 4 pages, 1 figure, to appear in the proceedings of ADASS XIX, Oct 4-8 2009, Sapporo, Japan (ASP Conf. Series

    Gravity theory in SAP-geometry

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    The aim of the present paper is to construct a field theory in the context of absolute parallelism (Teleparallel) geometry under the assumption that the canonical connection is semi-symmetric. The field equations are formulated using a suitable Lagrangian first proposed by Mikhail and Wanas. The mathematical and physical consequences arising from the obtained field equations are investigated.Comment: 14 pages, References added and a reference updated, minor correction

    Interference-Based Optimal Power-Efficient Access Scheme for Cognitive Radio Networks

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    In this paper, we propose a new optimization-based access strategy of multipacket reception (MPR) channel for multiple secondary users (SUs) accessing the primary user (PU) spectrum opportunistically. We devise an analytical model that realizes the multipacket access strategy of SUs that maximizes the throughput of individual backlogged SUs subject to queue stability of the PU. All the network receiving nodes have MPR capability. We aim at maximizing the throughput of the individual SUs such that the PU's queue is maintained stable. Moreover, we are interested in providing an energy-efficient cognitive scheme. Therefore, we include energy constraints on the PU and SU average transmitted energy to the optimization problem. Each SU accesses the medium with certain probability that depends on the PU's activity, i.e., active or inactive. The numerical results show the advantage in terms of SU throughput of the proposed scheme over the conventional access scheme, where the SUs access the channel randomly with fixed power when the PU is sensed to be idle

    Evaluating the Perception Among Rheumatologists of Maintenance of Board Certification in the US

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148252/1/acr23823.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148252/2/acr23823-sup-0001-AppendixS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148252/3/acr23823_am.pd

    The Effect of Creatine Supplementation on the CPK Enzyme in Blood Serum and Some Physical Abilities for Wrestlers during the Competition Period.

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    Creatine phosphokinase (CPK) is a binary enzyme that stimulates reverse phosphorylation to regenerate adenosine triphosphate. Creatine supplementation improves the Phosphagen system by increasing the amount of free creatine and phosphocreatine available to replenish adenosine triphosphate. The aims of this study are to investigate the effects of a creatine supplement on CPK enzyme, muscular endurance, power and agility performance compared to a placebo among wrestlers during the competition in a double-blind and randomized manner. Sixteen Wrestlers participated in the current study. They were divided into two groups; Experimental group (EXP) (n = 8) with creatine supplementation and a control group without creatine supplementation (CON) (n = 8). They were tested before (PRE) and after (POST) 8-week creatine supplementation period for CPK enzyme, muscular endurance [i.e. back-throw skill using the wrestling dummy], power [i.e. skill of the bridge], and agility [i.e. skill of the bridge in 10 sec.]. The results have shown statistically significant effects of the time (i.e. pre- to post-training) for all measured variables (p ≤ 0.05) of EXP group (whereas no significant effects (p ˃ 0.05) of CON group. There were statistically significant differences (p ≤ 0.05) at the POST evaluation of EXP group in comparison with CON group for all study variables

    An update on belimumab for the treatment of lupus

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    B-lymphocyte stimulator (BLyS), a homeostatic factor for B-cell differentiation and survival, has a major role in B-cell expansion and autoreactivity that characterize systemic lupus erythematosus (SLE). Belimumab, a BLyS-specific inhibitor, has shown promising evidence of efficacy in several preclinical and clinical studies in SLE. Two recent large randomized controlled trials yielded a significant positive effect of the drug compared to placebo in patients with active disease. In this review, we discuss basic aspects of B-cell and BLyS biology in SLE and summarize the evidence supporting a role of belimumab in SLE, from animal studies to phase III clinical trials

    Mixing Within Patterned Vortex Core

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    The video shows the flow dynamics within inner and outer regions of a vortex core. The observed phenomena mimic a transport process occurring within the Antarctic vortex. The video shows two distinct regions: a strongly mixed core and broad ring of weakly mixed region extending out the vortex core boundaries. The two regions are separated by a thin layer that isolates the weakly and strongly mixed regions; this thin layer behaves as barrier to the mixing of the two regions. The video shows that the barriers deplete when a swirl of the vortex core increases and the vortex core espouses a triangular pattern.Comment: 62nd Annual Meeting of the APS Division of Fluid Dynamics, Fluid Dynamics Vide
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