著者
Tadaaki BAN-NAI Yasuyuki MURAMATSU Satoshi YOSHIDA
出版者
Journal of Radiation Research Editorial Committee
雑誌
Journal of Radiation Research (ISSN:04493060)
巻号頁・発行日
vol.45, no.2, pp.325-332, 2004 (Released:2004-08-10)
参考文献数
58
被引用文献数
13

Mushrooms are known to accumulate radiocesium. To estimate the intake of radiocesium through the eating of mushrooms, about 30 samples belonging to 4 commonly consumed species (Lentinula edodes, Hypsizigus marmoreus, Grifola frondosa, and Tricholoma matsutake), were analyzed for 137Cs and 40K. The concentration ranges were 0.060-29 Bq kg-1 (wet wt) for 137Cs and 38-300 Bq kg-1 (wet wt) for 40K. The geometric mean concentration for 137Cs was 0.56 Bq kg-1 (wet wt), and the mean concentration for 40K was 92 Bq kg-1 (wet wt). The 137Cs concentrations in L. edodes cultivated in mushroom beds (sawdust-rice bran media) were lower than those cultivated on bed logs (natural wood with bark). The annual intake of 137Cs per person through mushrooms was calculated, by using the current analytical results and food consumption data in Japan, to be 3.1 Bq for 137Cs, which is about 28% of the total dietary intake of this nuclide. The effective dose equivalent of 137Cs through mushrooms was estimated to be 4.0 ¤ 10-8 Sv, which is about the half the value obtained in our previous study. The decrease of the 137Cs intake through mushrooms is probably related to changes in cultivation methods in recent years, from the use of bed logs to mushroom beds.
著者
吉田 暁史 Satoshi YOSHIDA
出版者
大手前大学
雑誌
大手前大学人文科学部論集 = Otemae journal of humanities (ISSN:13462105)
巻号頁・発行日
vol.7, pp.A113-A134, 2006-03-31

ネットワーク環境における主題検索研究に関しては、あまり顕著な進展はない。その中で、FASTという主題検索システムが登場した。LC件名標目表の豊富な語彙をほぼそのまま借用し、統語論的結合については簡略化したシステムである。LC件名標目表は、意味論的側面、統語論的側面の両方で、大きな問題を抱えている。本論ではLC件名標目表において、名辞の形、意味論的関係性、統語論的結号の各側面について検討する。次にFASTがどのような目的で、どのような経緯で出現したかを論じる。さらに上記それぞれの側面で、LC件名標目表をどのように継承し、LC件名標目表とどのように異なるかを調べる。最後にネットワーク情報資源の検索にとってあるべき姿を論じる。結論としては、(1)もはや事前結合索引にこだわるべきではなく、事後結合索引の方向に向かうべきである、(2)件名典拠ファイルは、語彙管理の部分と統語論的結合部分とに分離し、FASTはそのうちの語彙管理部分をLC件名標目表と共有すべきである、と指摘する。
著者
Satoshi YOSHIDA
出版者
The Ceramic Society of Japan
雑誌
Journal of the Ceramic Society of Japan (ISSN:18820743)
巻号頁・発行日
vol.128, no.7, pp.340-348, 2020-07-01 (Released:2020-07-01)
参考文献数
60

The indentation test using a sharp diamond indenter, such as a Vickers indenter, has been long employed for comparing mechanical properties among various glass compositions, because of its simple procedure and easy operation. However, mechanisms of permanent deformation and crack nucleation in glass are far from simple. This has made it difficult to understand what controls the threshold load for cracking in a certain glass during indentation. In this review, the author’s works on indentation-induced deformation and cracking in glass are introduced, and relevant issues on the indentation technique are discussed. Especially, it is pointed out that permanent densification of glass under the indenter is a key phenomenon which controls the following cracking event. Further, it is also shown that the micro-photoelastic observation system, by which the indentation-induced stress field can be visualized, and the indentation microscope, which enables one to measure the contact area between glass and the indenter, are powerful tools to stimulate new and fresh ideas for improving mechanical properties of glass.
著者
Satoshi Yoshida Takashi Uemura Takuya Kida Tatsuya Asai Seishi Okamoto
出版者
Information and Media Technologies 編集運営会議
雑誌
Information and Media Technologies (ISSN:18810896)
巻号頁・発行日
vol.7, no.1, pp.129-140, 2012 (Released:2012-03-15)
参考文献数
32

We address the problem of improving variable-length-to-fixed-length codes (VF codes). A VF code that we deal here with is an encoding scheme that parses an input text into variable length substrings and then assigns a fixed length codeword to each parsed substring. VF codes have favourable properties for fast decoding and fast compressed pattern matching, but they are worse in compression ratio than the latest compression methods. The compression ratio of a VF code depends on the parse tree used as a dictionary. To gain a better compression ratio we present several improvement methods for constructing parse trees. All of them are heuristical solutions since it is intractable to construct the optimal parse tree. We compared our methods with the previous VF codes, and showed experimentally that their compression ratios reach to the level of state-of-the-art compression methods.