著者
平野 正徳 今城 健太郎 南 賢太郎 島田 拓弥
出版者
一般社団法人 人工知能学会
雑誌
人工知能学会第二種研究会資料 (ISSN:24365556)
巻号頁・発行日
vol.2022, no.FIN-028, pp.27, 2022-03-12 (Released:2022-10-21)

Deep Hedging, which uses deep learning and price time-series simulations to optimize option hedging, has recently been in the spotlight because it enables more realistic hedging that can take into account frictions such as transaction fees (imperfect market). However, the situation of hedging an option by other options has never been addressed by deep hedging because of its simulation difficulties. In that situation, pricing for tradable options should also be performed via deep hedging in simulations for realizing imperfect market simulations, which has required unrealizable enormous computational resources because of the nested architecture of deep hedging. Thus, in this study, we proposed a new deep-hedging mechanism for learning hedging strategies under such a nested situation. As a result, we showed better hedging via proposed deep hedging with multiple tradable options.
著者
島田 拓司
出版者
天理大学言語教育研究センター
雑誌
外国語教育 : 理論と実践 (ISSN:02881942)
巻号頁・発行日
no.40, pp.1-15, 2014

本稿の目的は,Gelfand et al(2006;2011)による厳格な文化-寛容な文化という新しい比較文化研究のパラダイムをレビューし,異文化コミュニケーション研究への適用可能性について検討することである。具体的には,制御焦点理論と文化的自己観理論に関する先行研究に基づき,社会レベルの厳格さ-寛容さという概念と個人レベルの制御焦点(促進焦点vs.予防焦点)の関連を検討し,制御焦点と自尊心の相関を比較した日米比較調査の結果を報告する。そして,この結果に基づき, 社会レベルの厳格さ-寛容さ,個人レベルの促進焦点・予防焦点,および仲介変数としての自尊感情,面子を関連づける理論モデルを提案する。
著者
島田 拓 臺丸谷 政志 小林 秀敏 藤木 裕行 シレガル ラクマド・アリフ
出版者
一般社団法人日本機械学会
雑誌
年次大会講演論文集
巻号頁・発行日
vol.2004, pp.193-194, 2004

This paper is concerned with the tensile strength and strain rate of concrete materials by means of the experimental method of reflected tensile stress waves. The experiment is conducted by the Hopkinson bar technique and it is based on the superposition and concentration of tensile stress waves reflected both from the free ends of a striking bar and a specimen bar. The impact tensile experiment for concrete materials was carried out and the tensile strength of concrete under impact loadings was discussed as well as the effect of strain rates. This study is focused on the measurement of strain rates using both strain gages and crack gages. It is found that the impact tensile strength of concrete is remarkably influenced by strain rates ranging from 10^0 to 10^2 sec^<-1>.