著者

古谷 俊明 平井 正史 大山 宏

出版者

一般社団法人日本建築学会

雑誌

学術講演梗概集. 構造系

巻号頁・発行日

vol.52, pp.1259-1260, 1977-10

著者

雄山 厚 大山 宏 河本 典之

出版者

一般社団法人 映像情報メディア学会

雑誌

テレビジョン (ISSN:18849644)

巻号頁・発行日

vol.28, no.10, pp.805-810, 1974 (Released:2011-03-14)

参考文献数

5

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VHFテレビ受信用の小型単指向性アンテナを開発した.このアンテナは2本の放射素子を用い, ハイブリッド回路, 移相回路および整合回路を介して位相給電したものであり, VHFテレビ全帯域にわたって単方向の指向性を示すものである.また小型化しているが, その利得は-5~+2.5dB程度であり, E面指向性はVHFテレビオールバンド8素子アンテナと同等なので, 強・中電界では従来の八木アンテナに代って使用できる.

著者

大山 宏 齋藤 真哉 佐治 真由子

出版者

日本公民館学会

雑誌

日本公民館学会年報 (ISSN:1880439X)

巻号頁・発行日

vol.16, pp.45-54, 2019-11-30 (Released:2019-12-29)

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The purpose of this paper is to uncover the historical processes that have led to the formation and development of social education facilities in large metropolitan areas, using Itabashi City in Tokyo as a case study.The introduction of social education facilities in Tokyo came later than the national trend because of its policy of focusing on people rather than buildings. At first, facilities that catered to youth were turned into social education facilities for residents of all generations. After that, they became lifelong-learning centers. Since the 1990s, however, social education facilities have been in retreat. The location of classes or other learning activities have been moved from social education facilities to community centers near to where the people who participate actually live. Moreover, the role of social educator has also changed and has taken on that of a facilitator of the independent activities of the citizens in local communities.Taking these circumstances into consideration and by looking at the relationship between social education facilities and a proactive citizenry, we reached three findings. First, the connections between citizens, based on an awareness of the issues in their daily lives, have come to provide a consistent base of support for social education. Second, mutual learning initiatives have provided a foundation for bringing citizens together. Third, with social educators moving into local areas, policies that cover a wide geographical area are now being positioned within a local context. These three findings reveal the possibility that social education can be deployed and developed beyond the restrictions of the placement of administrative facilities.

著者

雄山 厚 大山 宏 河本 典之

出版者

一般社団法人 映像情報メディア学会

雑誌

テレビジョン (ISSN:18849644)

巻号頁・発行日

vol.23, no.2, pp.106-112, 1969-02-01 (Released:2011-03-14)

参考文献数

3

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これまでUHFテレビ受信用アンテナ (662-770MHz) として広く用いられている八木アンテナ, コーナレフレクタアンテナなどをさらに広帯域化 (470-770MHz) するために, その要となるまったく新しい放射器を開発した. この放射器は構造が簡単で, 理論的にもすぐれたインピーダンスを示しているが, さらに, この放射器を支持する絶縁材料の影響を有効に利用することにより, より広帯域なインピーダンスを示すように工夫した実用的な放射器である. この理論解析と実験結果を述べ, これを用いたUHFテレビ受信用広帯域アンテナの諸特性についても述べる.

著者

金子 康智 岸本 星太 森 一石 大山 宏治

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.861, pp.17-00447-17-00447, 2018 (Released:2018-05-25)

参考文献数

13

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Although, in designing blades, it is assumed that all blades on a disk are identical (tuned system), the vibration characteristics of the blade is slightly different due to the manufacturing tolerance, the deviation of the material property, and so on (mistuned system). As a result, in the forced response of an actual bladed disk caused by the flow distortion, the responses of all the blades on a disk become different, and the response of a certain blade may become extremely large, due to the split of the duplicated natural frequencies, the distortion of the vibration modes, and so on. On the other hand, it is suggested by many researchers that the mistuning suppresses the blade flutter, because the complete travelling wave mode is not formed in a disk. In other words, the effect of the mistuning acts on the dangerous side for the forced vibration, while on the safety side for the blade flutter. In this study, the stability analysis and the frequency response analysis of mistuned bladed disks are carried out using the reduced model with high fidelity, in order to research the vibration characteristics of typical mistuned bladed disks. Based on the analysis results, an optimal design procedure of mistuned bladed disks considering both the forced response and the self-excited vibration is proposed.

著者

金子 康智 今井 貴彦 森 一石 大山 宏治

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.850, pp.16-00536-16-00536, 2017 (Released:2017-06-25)

参考文献数

9

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A vane used in a low pressure end of steam turbine is usually fixed to an inner shroud and an outer ring by welding both ends. In such a vane structure, the damping in loading operation is comprised of the material damping and the aerodynamic damping, because the structural damping is very small. In addition, steam turbine vanes are sometimes manufactured in a half-ring structure, where all vanes in a upper half and a lower half are connected by the shroud. In such a half-ring structure, the vane exhibits closely spaced natural frequencies of Toop (Tangential out-of-phase) modes, in which each vane in a half-ring vibrates like a fixed-fixed beam in a different phase. In such a steam turbine vane, the forced vibration and the self-excited vibration of Toop modes may become a serious issue. Therefore, in the design of the steam turbine vane, it becomes indispensable to evaluate the resonant response and the stability of Toop modes under the high loading condition. In this study, first, the vibration characteristics of steam turbine vane with a half-ring structure are studied by use of the results of FE analysis. Second, the reduced order model (the equivalent spring-mass model) of a half-ring structure is assembled, based on the results of FE analysis. Finally, the forced response analysis of the mistuned system of a half-ring structure is carried out, using the reduced order model and the Monte Carlo simulation. From these results, the vibration response characteristics of steam turbine vane with a half-ring structure are clarified.

著者

雄山 厚 大山 宏 河本 典之

出版者

一般社団法人映像情報メディア学会

雑誌

テレビジョン (ISSN:03743470)

巻号頁・発行日

vol.28, no.10, pp.805-810, 1974-10-01

被引用文献数

3

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VHFテレビ受信用の小型単指向性アンテナを開発した.このアンテナは2本の放射素子を用い, ハイブリッド回路, 移相回路および整合回路を介して位相給電したものであり, VHFテレビ全帯域にわたって単方向の指向性を示すものである.また小型化しているが, その利得は-5〜+2.5dB程度であり, E面指向性はVHFテレビオールバンド8素子アンテナと同等なので, 強・中電界では従来の八木アンテナに代って使用できる.