- 著者
- Kahori Ogashiwa Masao Mori Sachio Hirokawa
- 出版者
- Japanese Society for Information and Systems in Education
- 雑誌
- The Journal of Information and Systems in Education (ISSN:1348236X)
- 巻号頁・発行日
- vol.19, no.1, pp.15-20, 2020 (Released:2020-07-01)
- 参考文献数
- 12
This paper attempts to discover the distinguishing characteristics of Japanese national universities, and to determine the strengths of each university by analyzing their midterm goals. We propose a method that extracts words from documents, analyzes them, and visualizes the features of documents on the basis of these extracted words. We developed two systems, a cross-tabulation search engine and a keyword map search engine, for the midterm goal document. In these systems, the user both decides the viewpoint to be compared and analyzed and inputs the search word, so that the relation of the words related to the search word is visualized, and a novel comparison analysis method among university organizations is realized. In this paper, we report the outline of these systems and the results of the verification of the two systems, using “regional contribution” as an example.
1 0 0 0 IR Discrimination of heavy elements originating from PopIII stars in z= 3 intergalactic medium
- 著者
- 梅村 雅之 森 正夫 Takanobu Kirihara Kenji Hasegawa Masayuki UMEMURA Masao MORI Tomoaki Ishiyama
- 出版者
- Oxford University Press
- 雑誌
- Monthly Notices of the Royal Astronomical Society (ISSN:00358711)
- 巻号頁・発行日
- vol.491, no.3, pp.4387-4395, 2019-12
We investigate the distribution of metals in the cosmological volume at z ∼ 3, in particular, provided by massive Population III (Pop III) stars using a cosmological N-body simulation in which a model of Pop III star formation is implemented. Owing to the simulation, we can choose minihaloes where Pop III star formation occurs at z > 10 and obtain the spatial distribution of the metals at lower redshifts. To evaluate the amount of heavy elements provided by Pop III stars, we consider metal yield of pair-instability or core-collapse supernovae (SNe) explosions of massive stars. By comparing our results to the Illustris-1 simulation, we find that heavy elements provided by Pop III stars often dominate those from galaxies in low-density regions. The median value of the volume averaged metallicity is Z∼10−4.5−−2Z⊙ at the regions. Spectroscopic observations with the next generation telescopes are expected to detect the metals imprinted on quasar spectra.