Kazuya Matsumoto

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—OpenCL (Open Computing Language) is a framework for general-purpose parallel programming. Programs written in OpenCL are functionally portable across multiple processors including CPUs, GPUs, and also FPGAs. Using an auto-tuning technique makes performance of OpenCL programs also portable on different processors. We have developed an auto-tuning system(More)
Contribution ◮ Blocked algorithm for the all-pairs shortest (APSP) paths problem for a hybrid CPU-GPU system. ◮ Applicable to solve the APSP problem even when the required memory size is larger than GPU's memory capacity. ◮ Fastest among existing APSP solutions on large dense graphs. ◮ Discussion on required memory bandwidth for the blocked algorithm. The(More)
SUMMARY The All-Pairs Shortest Paths (APSP) problem is a graph problem which can be solved by a three-nested loop program. The Cell Broadband Engine (Cell/B.E.) is a heterogeneous multi-core processor that offers the high single precision floating-point performance. In this paper, a solution of the APSP problem on the Cell/B.E. is presented. To maximize the(More)
We analyzed the effects of age and sex on habitual sleep/wake rhythm and Morningness-Eveningness scores of 2,252 subjects (6-89 years) randomly selected in Shimonoseki, Japan. Subjects were divided into 21 age groups with a matching number of men and women in each age group. The most common sleep parameter patterns by age showed a v- or inverted v-pattern(More)
The abundant pigment-protein membrane complex photosystem-I (PS-I) is at the heart of the Earth's energy cycle. It is the central molecule in the "Z-scheme" of photosynthesis, converting sunlight into the chemical energy of life. Commandeering this intricately organized photosynthetic nanocircuitry and re-wiring it to produce electricity carries the promise(More)
SUMMARY This paper presents a blocked united algorithm for the all-pairs shortest paths (APSP) problem. This algorithm simultaneously computes both the shortest-path distance matrix and the shortest-path construction matrix for a graph. It is designed for a high-speed APSP solution on hybrid CPU-GPU systems. In our implementation, two most compute intensive(More)
To understand the sleep-wake behaviours from the fifth pre-partum week to the 15th post-partum week by the number of actigraphic activities and sleep logs were evaluated in 10 women. It was found that total sleep time shortened, sleep efficiency decreased, and wake after sleep onset (WASO) increased in the weeks immediately after delivery. Compared with(More)
Reduction and oxidation in transition-metal oxides are keys to develop technologies related to energy and the environment. Here we report the selective topochemical reduction observed when artificial superlattices with transition-metal oxides are treated at a temperature below 300 °C with CaH(2). [CaFeO(2)](m)/[SrTiO(3)](n) infinite-layer/perovskite(More)