47 research outputs found

    Parallel Particle-In-Cell Plasma Simulations on GPU, Vector, and Scalar Systems

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    The calculation performance of two types of moment calculation algorithms are evaluated on a GPU system with nVIDIA C2070 board and vector-type system on the Earth Simulator for one of the particle-in-cell plasma simulations. Those are WORK and SORT algorithms. The performances are compared with the scalar system (Intel Xeon) performance. We use 8 byte double precision variables for physical memory on both CPU and GPU chips. The used simulation algorithm is three-dimensional Hybrid code for ion-ion beam instability with periodic boundary system.OS6-9; 31st JSST Annual Conference (September 27-28, 2012, Kobe University, Japan) / Authors from proceedings TO

    Diagnostic Performance of Positron Emission Tomography for the Presurgical Evaluation of Patients with Non-lesional Intractable Partial Epilepsy : Comparison among 18F-FDG, 11C-Flumazenil, and 11C-Flumazenil Binding Potential Imaging Using Statistical Imaging Analysis

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    To compare the diagnostic performance of 18F-FDG PET, 11C-FMZ PET, and 11C-FMZ BP imaging for the evaluation of patients with intractable partial epilepsy whose MRI findings are normal by using statistical imaging analysis. Ten patients underwent comprehensive presurgical evaluation, including PET studies, to assess the epileptic foci. The extent of cortical resection was based on the results of intracranial video-electroencephalography (IVEEG) monitoring and brain mapping under stimulation. The images of 10 patients and 30 controls were spatially normalized to templates generated in-house by non-rigid registration and the standardized images of the patients and controls were statistically compared. Epileptic focus candidates were visualized on a color map of axial images of each template and the focus site was identified in candidates for lobar location. In patients with Engel I postoperative seizure outcomes we assessed the sensitivity and specificity of the imaging methods for lobar focus localization. We also compared the concordance scores of patients with Engel I and Engel II-IV postoperative seizures. The sensitivity and specificity for lobar focus localization on 18F-FDG PET scans was 90.0% and 84.8%, respectively; it was 30.0% and 81.4% for 11C-FMZ PET, 40.0% and 66.7% for 11C-FMZ BP images, and 100.0% and 51.4% for 18F-FDG PET/11C-FMZ PET/11C-FMZ BP images. In one patient the epileptic focus not detected on 18F-FDG PET scans was shown on 11C-FMZ BP images. In patients with Engel I post-treatment seizures the concordance scores were significantly higher for 18F-FDG PET than 11C-FMZ PET and 11C-FMZ BP images (p < 0.05). With respect to sensitivity and specificity, 18F-FDG PET was superior to 11C-FMZ PET and 11C-FMZ BP imaging. However, in some patients with normal MRI results, 11C-FMZ BP studies may complement 18F-FDG PET findings in efforts to identify the epileptogenic lobar regions

    Effects of jump and balance training on knee kinematics and electromyography of female basketball athletes during a single limb drop landing: pre-post intervention study

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    <p>Abstract</p> <p>Background</p> <p>Some research studies have investigated the effects of anterior cruciate ligament (ACL) injury prevention programs on knee kinematics during landing tasks; however the results were different among the studies. Even though tibial rotation is usually observed at the time of ACL injury, the effects of training programs for knee kinematics in the horizontal plane have not yet been analyzed. The purpose of this study was to determine the effects of a jump and balance training program on knee kinematics including tibial rotation as well as on electromyography of the quadriceps and hamstrings in female athletes.</p> <p>Methods</p> <p>Eight female basketball athletes participated in the experiment. All subjects performed a single limb landing at three different times: the initial test, five weeks later, and one week after completing training. The jump and balance training program lasted for five weeks. Knee kinematics and simultaneous electromyography of the rectus femoris and Hamstrings before training were compared with those measured after completing the training program.</p> <p>Results</p> <p>After training, regarding the position of the knee at foot contact, the knee flexion angle for the Post-training trial (mean (SE): 24.4 (2.1) deg) was significantly larger than that for the Pre-training trial (19.3 (2.5) deg) (p < 0.01). The absolute change during landing in knee flexion for the Post-training trial (40.2 (1.9) deg) was significantly larger than that for the Pre-training trial (34.3 (2.5) deg) (p < 0.001). Tibial rotation and the knee varus/valgus angle were not significantly different after training. A significant increase was also found in the activity of the hamstrings 50 ms before foot contact (p < 0.05).</p> <p>Conclusions</p> <p>The jump and balance training program successfully increased knee flexion and hamstring activity of female athletes during landing, and has the possibility of producing partial effects to avoid the characteristic knee position observed in ACL injury, thereby preventing injury. However, the expected changes in frontal and transverse kinematics of the knee were not observed.</p

    Effect of Monomer Sequence along Network Chains on Thermoresponsive Properties of Polymer Gels

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    The effect of monomer sequence along the network chain on the swelling behavior of polymer gels should be clarified for the advanced control of swelling properties of gel materials. To this end, we systematically investigated the swelling properties of poly(acrylamide derivative) gels with the same composition but different monomer sequence by utilizing two gel synthetic methods: copolymerization giving a random network and co-crosslinking giving a blocky network. Both of the copolymerization and the co-crosslinking gels were prepared from the combination of two of the three following monomers: hydrophilic N,N-dimethylacrylamide (DMAAm), hydrophobic N-n-butylacrylamide (NBAAm), and thermoresponsive N-isopropylacrylamide (NIPAAm) with various monomer compositions. The swelling measurement of the obtained gels showed totally different behaviors between the copolymerization and the co-crosslinking gels, even with the same monomer composition. The copolymerization gels had the average property from the two monomers, depending on monomer composition, because random monomer distribution changed the affinity of each network chain to water. On the other hand, the co-crosslinking gels behaved as if two components independently contributed to the swelling properties, probably due to the domain structure derived from two kinds of prepolymers

    Three-dimensional surface models of autopsied human brains constructed from multiple photographs by photogrammetry.

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    Virtual three-dimensional (3D) surface models of autopsied human brain hemispheres were constructed by integrating multiple two-dimensional (2D) photographs. To avoid gravity-dependent deformity, formalin-fixed hemispheres were placed on non-refractile, transparent acrylic plates, which allowed us to take 2D photographs from various different angles. Photogrammetric calculations using software (ReCap Pro cloud service, Autodesk, San Rafael, CA, USA) allowed us calculate the 3D surface of each brain hemisphere. Virtual brain models could be moved and rotated freely to allow smooth, seamless views from different angles and different magnifications. When viewing rotating 3D models on 2D screens, 3D aspects of the models were enhanced using motion parallax. Comparison of different brains using this method allowed us to identify disease-specific patterns of macroscopic atrophy, that were not apparent in conventional 2D photographs. For example, we observed frontal lobe atrophy in a progressive supranuclear palsy brain, and even more subtle atrophy in the superior temporal gyrus in amyotrophic lateral sclerosis-frontotemporal lobar degeneration. Thus, our method facilities recognition of gyral atrophy. In addition, it provides a much more powerful and suitable way of visualizing the overall appearance of the brain as a three-dimensional structure. Comparison of normal and diseased brains will allow us to associate different macroscopic changes in the brain to clinical manifestations of various diseases

    Micro Sun Sensor with CMOS Imager for Small Satellite Attitude Control

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    A new type of Micro Sun Sensor (MSS) was started development for use on JAXA’s small satellites and space exploring spacecraft as attitude sensor. In recent years, small satellites are used for various missions, such as the Earth observation and science observation, and high functional attitude control system for small satellite is also required. Therefore, the sun sensor for small satellite is required to be good balance of its dimension, mass, power consumption and performance. The detector of the MSS is a CMOS Active Pixel Sensor (APS). The adoption of the CMOS APS contributes to simplicity and compactness on the MSS. The MSS is equipped with a commercial-grade CMOS APS. The state-of-the-art commercial APS is low cost and high performance. For radiation effect investigation, the tolerance for gamma rays and proton irradiation were tested. The Ground Test Model (GTM) of the MSS was fabricated and also has been tested. This paper reports the description of the MSS, the result of the radiation test for commercial APS and ground optical performance test of the MSS GTM
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