Sound Generation by a Turbulent Flow in Musical Instruments - Multiphysics Simulation Approach -

Total computational costs of scientific simulations are analyzed between direct numerical simulations (DNS) and multiphysics simulations (MPS) for sound generation in musical instruments. In order to produce acoustic sound by a turbulent flow in a simple recorder-like instrument, compressible fluid dynamic calculations with a low Mach number are required around the edges and the resonator of the instrument in DNS, while incompressible fluid dynamic calculations coupled with dynamics of sound propagation based on the Lighthill's acoustic analogy are used in MPS. These strategies are evaluated not only from the viewpoint of computational performances but also from the theoretical points of view as tools for scientific simulations of complicated systems.Comment: 6 pages, 10 figure files, to appear in the proceedings of HPCAsia0

Head-Trajectory-Tracking Control of a Snake Robot and Its Robustness Under Actuator Failure

This brief considers the problem of trajectory tracking of a planar snake robot without a lateral constraint. The reference trajectory of the head position and the orientation of link 1 are given, and torque control is determined to reduce tracking errors. The performance of the controller was tested in a number of simulations. The robustness during actuator failure was also studied. We assumed that one of the actuators was broken and the corresponding joint became passive. Furthermore, as a more realistic situation, we considered an instance when some of the states were not readily accessible from the sensor readings and needed to be estimated by an observer. The extended Kalman filter was employed for this purpose, and the performance of the closed-loop system with the observer was also tested in simulations

Effect of soil components on adsorption of Pepper Mild Mottle Virus by Japanese soils

Poster Sessio

Lowering the Energy Threshold using a Plastic Scintillator and Radiation-Damaged SiPMs

The radiation damage to a silicon photomultiplier (SiPM) set on a satellite orbit increases energy threshold for scintillator detectors. We confirmed that 1 krad of radiation increases the energy threshold by approximately a factor of 10, which is worst for our system. Using one or two SiPMs damaged by proton irradiation and a plastic scintillator, we performed the following three experiments in our attempt to lower the energy threshold of radiation-damaged SiPMs to the greatest extent: (1) measurements using a current waveform amplifier rather than a charge-sensitive amplifier, (2) coincidence measurements with two radiation-damaged SiPMs attached to one scintillator and summing up their signals, and (3) measurements at a low temperature. Our findings confirmed that the use of a current waveform amplifier, as opposed to a charge-sensitive amplifier and a shaping amplifier, could lower the energy threshold to approximately 65% (from 198 keV to 128 keV). Furthermore, if we set the coincidence width appropriately and sum up the signals of the two SiPMs in the coincidence measurement, the energy threshold could be lowered to approximately 70% (from 132 keV to 93 keV) with little loss of the acquired signal, compared to that of use of only one scintillator. Finally, if we perform our measurements at a temperature of -20 {\deg}C, we could lower the energy threshold to approximately 34% (from 128 keV to 43 keV) compared to that of at 20 {\deg}C. Accordingly, we conclude that the energy threshold can be lowered to approximately 15% by using a combination of these three methods.Comment: Accepted for publication in Nuclear Instruments and Methods in Physics Research Section A. Comments are welcome

A novel A792D mutation in the CSF1R gene causes hereditary diffuse leukoencephalopathy with axonal spheroids characterized by slow progression

Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is an autosomal dominant white matter disease that causes adult-onset cognitive impairment. The clinical manifestations are a variable combination of personality and behavioral changes, cognitive decline, parkinsonism, spasticity, and epilepsy. In 2012, mutations in the gene encoding colony stimulating factor 1 receptor (CSF1R) were identified as the cause of HDLS. As the numbers of reported mutations are limited, the understanding of whole pathogenesis needs accumulation of disease-causing mutations with detailed clinical descriptions. We describe a Japanese family with autosomal dominant adult-onset cognitive impairment and characteristic white matter lesions. Genetic testing revealed a novel p.A792D mutation in the tyrosine kinase domain of CSF1R in two affected family members. The symptom profile of the present cases mostly matched the previously reported cases, with the notable exceptions of late-onset and long disease duration

Free-bound excitation and predissociation of ytterbium dimers near the ¹S₀-¹P₁ atomic transition

A continuous excitation band of a free-bound photoassociation transition of ytterbium atoms is observed as a red wing of the ¹S₀-¹P₁ atomic line at 399 nm for a hot thermal vapor. The excitation to the 0u⁺ molecular state is observed by monitoring fluorescence from the ³P₁ state atoms, which allows us to detect the production of Yb₂ molecules with high sensitivity. The photoassociation is characterized in comparison with transitions to atomic Rydberg states. The time profile of the fluorescence signal suggests that the 0u⁺ molecular state predissociates with states correlating to the ¹S₀+³D₂ atomic states