{"created":"2023-05-15T12:09:50.123198+00:00","id":15396,"links":{},"metadata":{"_buckets":{"deposit":"200bc80b-3e86-4377-be93-5c9d3dfdc13e"},"_deposit":{"created_by":19,"id":"15396","owners":[19],"pid":{"revision_id":0,"type":"depid","value":"15396"},"status":"published"},"_oai":{"id":"oai:iwate-u.repo.nii.ac.jp:00015396","sets":["1515:1519"]},"author_link":["93148","93144","93147","93145","93146","93149"],"item_16_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2020-12-25","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"1","bibliographicPageEnd":"27","bibliographicPageStart":"16","bibliographicVolumeNumber":"77","bibliographic_titles":[{"bibliographic_title":"日本音響学会誌"}]}]},"item_16_date_6":{"attribute_name":"登録日","attribute_value_mlt":[{"subitem_date_issued_datetime":"2021-09-15"}]},"item_16_description_11":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"我々は既に，弾性体（コンクリート）表面上に振動センサを取り付け，インパルスハンマで同じ表面を打撃したとき，表面波に対する振動センサの応答波形が，ハンマの波形と指数関数的に減衰する正弦波で表現できるインパルスレスポンスの畳み込みで近似できることを，欠陥がないと考えられるダムにおける実験で明らかにした。そして，このインパルスレスポンスを表す五つのパラメータの一つが，打撃時刻から表面波がセンサに到達するまでの伝搬時間を表すことを明らかにした。また，有限差分時間領域（FDTD）法を用いたシミュレーションにより，表面波だけでなく，P 波やS 波の反射波に対する振動センサの応答波形も，ハンマの波形と指数関数的に減衰する正弦波で表現できるインパルスレスポンスの畳み込みで表すことができ，このインパルスレスポンスを表す五つのパラメータの一つから，打撃時刻から表面波あるいは反射波がセンサに到達するまでの伝搬時間を推定することができることを明らかにした。更に砂を充填する前のケーソンを用いた実験で，FDTD 法で得られた結果の妥当性を検証した。境界においては伝搬する波の一部がP 波からS 波，S 波からP 波へとモード変換することが知られており，欠陥があると多数の反射波が生じる。本論文では，複数のセンサを用いた指向性合成により不要な反射波は抑制し，欠陥からの反射波は残す方法を述べ，仙台港と八戸港での実験で得られた複数のデータを元に解析を行った結果，ケーソンに穴が開き中詰め砂が流出すると，上蓋の下に空気層ができ，上蓋の下面からの反射波は確実に検出できることを明らかにしている。この上蓋の下面からの反射波の有無で欠陥の有無が判定できる。そして，指向性合成により得られたピークの位置から欠陥の存在位置の絞り込みが可能になることを述べている。","subitem_description_type":"Abstract"}]},"item_16_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"93147","nameIdentifierScheme":"WEKO"}],"names":[{"name":"ABE, Masato"}]},{"nameIdentifiers":[{"nameIdentifier":"93148","nameIdentifierScheme":"WEKO"}],"names":[{"name":"FUJIOKA, Toyota"}]},{"nameIdentifiers":[{"nameIdentifier":"93149","nameIdentifierScheme":"WEKO"}],"names":[{"name":"NAGATA, Yoshifumi"}]}]},"item_16_link_13":{"attribute_name":"抄録（URL）","attribute_value_mlt":[{"subitem_link_text":"反射波の伝搬時間推定と指向性合成によるケーソンの非破壊診断","subitem_link_url":"https://www.jstage.jst.go.jp/article/jasj/77/1/77_16/_article/-char/ja"}]},"item_16_publisher_14":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"日本音響学会"}]},"item_16_relation_26":{"attribute_name":"DOI","attribute_value_mlt":[{"subitem_relation_type":"isIdenticalTo","subitem_relation_type_id":{"subitem_relation_type_id_text":"info:doi/10.20697/jasj.77.1_16","subitem_relation_type_select":"DOI"}}]},"item_16_rights_18":{"attribute_name":"権利","attribute_value_mlt":[{"subitem_rights":"© 2020 日本音響学会"}]},"item_16_source_id_25":{"attribute_name":"NCID","attribute_value_mlt":[{"subitem_source_identifier":"AN00186234","subitem_source_identifier_type":"NCID"}]},"item_16_source_id_9":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"24322040","subitem_source_identifier_type":"ISSN"},{"subitem_source_identifier":"03694232","subitem_source_identifier_type":"ISSN"}]},"item_16_text_4":{"attribute_name":"著者(機関)","attribute_value_mlt":[{"subitem_text_value":"岩手大学理工学部"},{"subitem_text_value":"岩手大学理工学部"},{"subitem_text_value":"岩手大学理工学部"}]},"item_16_version_type_27":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"安倍, 正人"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"藤岡, 豊太"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"永田, 仁史"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2021-09-15"}],"displaytype":"detail","filename":"nhokgks-v77n1p16-27.pdf","filesize":[{"value":"2.0 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hammer","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"Beamforming","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"Nondestructive technique","subitem_subject_language":"en","subitem_subject_scheme":"Other"}]},"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":"journal 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