SPH Simulations with Reconfigurable Hardware Accelerator

We present a novel approach to accelerate astrophysical hydrodynamical simulations. In astrophysical many-body simulations, GRAPE (GRAvity piPE) system has been widely used by many researchers. However, in the GRAPE systems, its function is completely fixed because specially developed LSI is used as a computing engine. Instead of using such LSI, we are developing a special purpose computing system using Field Programmable Gate Array (FPGA) chips as the computing engine. Together with our developed programming system, we have implemented computing pipelines for the Smoothed Particle Hydrodynamics (SPH) method on our PROGRAPE-3 system. The SPH pipelines running on PROGRAPE-3 system have the peak speed of 85 GFLOPS and in a realistic setup, the SPH calculation using one PROGRAPE-3 board is 5-10 times faster than the calculation on the host computer. Our results clearly shows for the first time that we can accelerate the speed of the SPH simulations of a simple astrophysical phenomena using considerable computing power offered by the hardware.Comment: 27 pages, 13 figures, submitted to PAS

Saving Behavior under the Influence of Income Risk: An Experimental Study

Individual subjects are experimentally tested for precautionary saving. We use a simplified experimental framework and decision supporting tool to show that subject's consumption is consistent with precautionary saving. We find that subjects overact in changing current income. However, those over-reactions cancel each other, and subject's consumption behavior is close to the optimal solutions on average.Precautionary Saving,Experiment

CONTEMPORARY DEVELOPMENTS IN JAPANESE ALTERNATIVE EDUCATION AND INTEGRATION OF HIKIKOMORI CHILDREN

Culture-bound disorders, or culture-bound mental disorders, are psychological disorders or syndromes that are considered specific or closely related to cultural factors and or particular ethno cultural groups By definition, the hikikomori (the term can also be used in the plural) is one who retires from the community in order to have a solitary lifestyle. The Japanese term hiki means "to pull" and komoru means "retiring" or "withdrawing," hence the sense of pulling out from the community. The hikikomori is acknowledged a uniquely Japanese phenomenon. The typical hikikomori is a male (80% are male), teenaged to 30 years old, who has resigned from school or job, with poor technical skills. usually, the subjects are unemployed, residing in a separate room in his parents' house, avoiding any contact or coming out, taking meals left at his door by his friends or parents, spending the day reading, browsing, viewing television, idling.  Article visualizations