{"created":"2021-03-01T06:51:51.784477+00:00","id":33117,"links":{},"metadata":{"_buckets":{"deposit":"3a2a529b-f513-47ab-b0df-19fad106ab75"},"_deposit":{"id":"33117","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"33117"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00033117","sets":["80:4535:4837:4843","9:504:4538:4839:4844"]},"author_link":["129153","129154","129155","129156","129157","129158"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"Development of the Borehole Easy-operation Long-period Seismometer (BELS Type 79) which has a Stable Period"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1979-11-30","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"1","bibliographicPageEnd":"146","bibliographicPageStart":"135","bibliographicVolumeNumber":"54","bibliographic_titles":[{"bibliographic_title":"東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo"}]}]},"item_4_description_13":{"attribute_name":"フォーマット","attribute_value_mlt":[{"subitem_description":"application/pdf","subitem_description_type":"Other"}]},"item_4_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"The most troublesome factor in the observation of long-period oscillation or ground tilt is the problem of drift. As to the drift of zero-point, we can reduce it by the technique of negative feedback. On the other hand, we cannot avoid the drift of characteristic period (or drift of tilting sensitivity) as far as we use the principle of horizontal pendulum, which is the most popular way to construct the long-period seismometers. That is because the period of horizontal pendulum is essentially sensitive to the ground tilt. In this circumstance, we intended to device a long-period seismometer which has a stable period for the ground tilt. For the suspension of the pendulum we adopted the method originally suggested by Eomberg in 1961. This type of pendulum has the following features. (1) The change of characteristic period due  to ground tilt is negligibly small. So, if we construct a long-period seismometer with this pendulum and combine it with negative feedback, we can obtain a very stable system which is free from both types of drift. (2) As adjustment of period and zero-point can be carried out independently, the settlement of this instrument is quite easy. (3) The shape of the pendulum is just adequate for the use in a borehole. The prototype model constructed in this  study has dimensions of 120φ×540 (diameter × height in mm), a weight of 8kg and is equipped with two kinds of transducers. One signal is proportional to the displacement by use of the Magnesensor (SONY Inc.) while the other two are proportional to the velocity using ordinary moving coils. The characteristic period of the pendulum can be varied from 2 sec to 20 sec, by changing the position of the attachment point of the suspension spring. Total performance of this seismometer was found to be satisfactory through the test observation of natural earthquakes at a borehole site and earth tide observation in the vault.","subitem_description_type":"Abstract"}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000033117","subitem_identifier_reg_type":"JaLC"}]},"item_4_publisher_20":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"東京大学地震研究所"}]},"item_4_source_id_10":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AN00162258","subitem_source_identifier_type":"NCID"}]},"item_4_source_id_8":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"00408972","subitem_source_identifier_type":"ISSN"}]},"item_4_subject_15":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"453","subitem_subject_scheme":"NDC"}]},"item_4_text_21":{"attribute_name":"出版者別名","attribute_value_mlt":[{"subitem_text_value":"Earthquake Research Institute, University of Tokyo"}]},"item_4_text_4":{"attribute_name":"著者所属","attribute_value_mlt":[{"subitem_text_value":"地震研究所技術部"},{"subitem_text_value":"富士川近く変動観測所"},{"subitem_text_value":"マサチューセッツ工科大"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"安藤, 誠一"}],"nameIdentifiers":[{"nameIdentifier":"129153","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"岡田, 義光"}],"nameIdentifiers":[{"nameIdentifier":"129154","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"安芸, 敬一"}],"nameIdentifiers":[{"nameIdentifier":"129155","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"大工原, 保"}],"nameIdentifiers":[{"nameIdentifier":"129156","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"鈴木, 喜吉"}],"nameIdentifiers":[{"nameIdentifier":"129157","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"原, 智美"}],"nameIdentifiers":[{"nameIdentifier":"129158","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-06-26"}],"displaytype":"detail","filename":"ji0541006.pdf","filesize":[{"value":"751.5 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0541006.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/33117/files/ji0541006.pdf"},"version_id":"8bbf52c2-2800-48ca-859b-aa9e1877a2e2"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"固有周期の安定な坑井用小型長周期地震計・傾斜計の開発","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"固有周期の安定な坑井用小型長周期地震計・傾斜計の開発","subitem_title_language":"ja"}]},"item_type_id":"4","owner":"1","path":["4843","4844"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2009-02-18"},"publish_date":"2009-02-18","publish_status":"0","recid":"33117","relation_version_is_last":true,"title":["固有周期の安定な坑井用小型長周期地震計・傾斜計の開発"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T04:08:50.711544+00:00"}