著者

鶴谷 亮人 TSURUYA Akito

出版者

法政大学大学院理工学・工学研究科

雑誌

法政大学大学院紀要 理工学・工学研究科編 (ISSN:21879923)

巻号頁・発行日

vol.55, 2014-03-24

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In this study, we consider a problem of finding factors results in penalty shootouts (abbreviated to PSO) of football games. We check up 143 official football games and after PSOs, the first kicking PSO teams are confirmed to have tendency win. London School of Economics and Political Science infer that first successes in PSO are main factor of wins in PSOs and they give pressures to the opponent teams. Our date reject above inference of LSE & PS. Therefore , we construct a simple stochastic model in which each PSO is independent with equal probability of success. We demonstrate algebraically that if the success rate of PSOs of the first kicking PSO team is higher than that of the opponent team, then firs kicking team wins. Furthermore, our date fit quite well to the demonstrated result. It is truth that our stochastic model explains to PSOs very well. However, because we cannot reject all of inference of LSE & PS, it is needs that further analysis of PSOs.

著者

山下 大輝 YAMASHITA Taiki

出版者

法政大学大学院理工学・工学研究科

雑誌

法政大学大学院紀要 理工学・工学研究科編 (ISSN:21879923)

巻号頁・発行日

vol.56, 2015-03-24

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Li8SiN4 (tetragonal structure) is expected as a cathode material of Li secondary batteries because it includes eight Li atoms in its 1/8-sublattice. Li8SiN4 is synthesized by the direct reaction between Li3N and Si with the molar ratio of 2.5:1 at 1073 K for 30 minutes under a nitrogen atmosphere of about 700 Torr. As grown crystals, which are light orange color, are confirmed to be single phase of Li8SiN4 with a = 10.148 Å and c = 9.567 Å by the X-ray diffraction method. A broad Raman peak observed at 586 cm-1 suggests the disordered structure between Li and Si. The band gap of Li8SiN4 evaluated using optical absorption and photoacoustic spectroscopy is about 2.4 eV. Li8SiN4 is a direct transition, which is slightly larger than the d-d electron transitions in the typical cathode materials LiMn2O4 and LiCoO2. For a 5 × 5 mm2 sized lithium secondary battery with the Li8SiN4 + Acetylene Black cathode / Propylene Carbonate + LiClO4 electrolyte / Li anode structure, the capacity for the discharge current of 10 μA is between 2.44 μAh/cm2 and 3.56 μAh/cm2 for a potential range between 2.8 V and 3.8 V.