{"created":"2021-03-01T06:51:33.635127+00:00","id":32843,"links":{},"metadata":{"_buckets":{"deposit":"703c7a07-cd66-48d1-b9bf-e71869bad49c"},"_deposit":{"id":"32843","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"32843"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00032843","sets":["80:4535:4757:4761","9:504:4538:4759:4762"]},"author_link":["127981","127980"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"成層半無限の弾性体上にある半円形の地形にもとづくレーリー波の散乱について"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1988-01-29","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"3","bibliographicPageEnd":"200","bibliographicPageStart":"163","bibliographicVolumeNumber":"62","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 expressions for the energy of the scattered waves are theoretically obtained for the incidence of a train of periodic Rayleigh waves upon the semi-circular mountain in the semi-infinite elastic space with the upper layer. The evaluation of these expressions was carried out numerically. In the model with the upper layer we can expect two types of trapped waves along the free surface and the interface. One is the well-known Rayleigh waves which exponentially decrease in amplitude toward the inside of the medium. The other is the waves which have trigonometric components in the inside of the lower medium. The second type of waves is named as leaky mode. The waves of leaky mode, though very unstable, have strong effects on the partition of the energy in the scattering problem con- sidered here. In the problems of the surface waves along the plane free surface the study of the leaky mode of the waves has been omitted so far, because it readily disappears due to the unstableness of the waves. However, in the problems along the irregular surface the importance of this type of waves arise. In general, occurrences of the resonant standing P and S waves of leaky mode cause the depression of the transmissibility of the energy of the transmitted waves and, as a reciprocal effect, cause an increase of the energy of the scattered body waves, particularly the S waves. Even in the model with the upper layer (this study) we can expect the same behavior of the energy of the transmitted Rayleigh waves as that in the case without the upper layer (studied before). That is to say, (a) the occurrences of the resonant standing S and P waves in the mountain results in an abrupt decrease of the transmissibility of the transmitted Rayleigh waves through the mountain, and (b) on the contary, the standing Rayleigh waves along the curved surface causes the inverse result, i.e., the higher transmissibility of the transmitted Rayleigh waves.","subitem_description_type":"Abstract"},{"subitem_description":"(1)本論文において得られた最も重要で興味ある特性は,PまたはS波の振幅が媒質内部で三角関数(sine, cosine)的に変化する共鳴定常波(leaky mode)が地表近くに発生したとき,地表にある半円形地形に突入したレーリー波によって起こされた散乱波群(透過および反射レーリ一波,弾性体内部への散乱実体PおよびS波よりなる)へのエネルギーが下記のような異常な配分を受けることである.一般に,上述の定常波の存在は透過レーリー波へのエネルギー配分を低下させ,弾性体内部への散乱実体PおよびS波へのエネルギー配分を増加させる.(2)前に,筆者(1980b)は層をもたない半無限弾性体の表面にある半円形の起伏によるレーリー波の散乱についての研究を行った.そのとき得られた結果は今回の研究でもやはり見いだされている.すなわち,(a)半円形の山の部分に発生する共鳴定常PまたはS波は透過レーリー波の透過性を低下させ,(b)半円形の山の部分に発生する定常レーリー波は透過レーリー波の透過性を逆に高める.今回の研究では,地表面の近くに発生するleakyな定常P,S波の影響が上述の(a)(b)にもとづく散乱波のエネルギー配分の変化に更に上乗せするかたちで現れている.(3)透過レーリー波の第一のモードだけが存在する状態から第二のモードが発生する直前で透過レーリー波の総エネルギー(第一,第モードの和)は減少し,その減少したエネルギーは散乱実体S波として媒質内部に散乱される.そしてそのエネルギーは主に,上層と下層の境界面に沿って伝播する.(4)上下の層で媒質の密度に変化がある場合,下層の密度が上層の密度にたいして増加していくとき,半円形の山を透過していくレーリー波の透過性は次第に良くなってゆく.実際の地層では,一般に下層へゆくほど媒質の密度は増加して行く.したがってこの実際の地層構造はレーリー波の透過性を助けていることになる.","subitem_description_type":"Abstract"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"127981","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Momoi, Takao"}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000032843","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"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"桃井, 高夫"}],"nameIdentifiers":[{"nameIdentifier":"127980","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":"ji0623001.pdf","filesize":[{"value":"1.9 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0623001.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/32843/files/ji0623001.pdf"},"version_id":"5ba7feb2-dffd-42cf-8dba-24fd65eb5f3f"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"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":"Scattering of Rayleigh Waves by a Semi-circular Rough Surface on Layered Media","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Scattering of Rayleigh Waves by a Semi-circular Rough Surface on Layered Media","subitem_title_language":"en"}]},"item_type_id":"4","owner":"1","path":["4761","4762"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2008-05-30"},"publish_date":"2008-05-30","publish_status":"0","recid":"32843","relation_version_is_last":true,"title":["Scattering of Rayleigh Waves by a Semi-circular Rough Surface on Layered Media"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T05:38:02.259056+00:00"}