{"created":"2021-03-01T06:51:45.742501+00:00","id":33026,"links":{},"metadata":{"_buckets":{"deposit":"0b637683-eb73-4948-90ef-7f447eba7db5"},"_deposit":{"id":"33026","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"33026"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00033026","sets":["80:4535:4817:4823","9:504:4538:4819:4824"]},"author_link":["128770","128769"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"波線理論による弾性球の伸び縮み振動の特性方程式の導出"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1981-09-30","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"2","bibliographicPageEnd":"308","bibliographicPageStart":"277","bibliographicVolumeNumber":"56","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":"In Section II, we discuss from a viewpoint of ray theory the frequency equations of the spheroidal oscillations of the Earth consisting of a uniform solid mantle and a uniform liquid core. It is shown that the equations which yield discrete eigenfrequencies are derived from a certain interference condition of body waves traveling in the Earth. The equations are expressed in different forms corresponding to different ray situations in the Earth and they are proved to be identical with the asymptotic frequency equations obtained in terms of the normal mode theory. The interference condition thus proved to be valid then enables us to interpret the free oscillation in terms of ray theory. It is shown that the wave conversion of P to S or S to P at a boundary in the Earth induces the solotone effect in the distribution of eigenfrequencies of the modes for a fixed phase velocity. In Section III, discussion is extended to the Earth in which wave velocities change continuously as functions of the radius in the mantle and in the core respectively. We then formally get frequency equations identical to those for the above homo./homo. case. The validity of the equations is confirmed by the numerical computation for a realistic Earth model. Employing these equations, we can easily evaluate the approximate eigenfrequencies of high radial modes of spheroidal oscillations of a radially heterogeneous Earth.","subitem_description_type":"Abstract"},{"subitem_description":"近年,自由振動の特性方程式の漸近的性質に関する研究が盛んであるが,殆んどの場合がノーマル・モード理論に基づいた議論である.しかし,それが短周期近似による議論である以上,得られる主要項は波線理論的に解釈されるべき量の筈である.にもかかわらずこの方面からの研究は十分には行われていない.本研究の第II節では,均質なマントルと均質な流体核より成る地球を仮定し,その伸び縮み振動の特性方程式を波線理論的に導くことを試みる.先ず,球内部で多重反射する実体波の或る種の干渉条件より特性方程式を導く.その際種々の波線伝播状態に対応して異なった式が得られるが,それらはノーマル・モード理論によって既に得られている漸近的特性方程式に完全に一致する.この事は,用いられた実体波の干渉条件の妥当性を証明するものである.それは同時に,自由(固有)振動の波線理論的解釈を明らかにするものでもある.言い換えると,自由(固有)振動とは,各モードに固有のP波とS波の振幅が球内のある深さで常に一定に保たれている状態ということが出来る.またその状態を数式化したもの(その状態を保証するもの)が特性方程式である.第III節では,上の波線理論による方法が,弾性常数が深さの関数として連続的に変化している球モデルにも適用できることを示す.その際得られる特性方程式は,形式的には上の均質モデルの場合に導かれた式に一致し,その有効性は数値計算によって証明される.これらの式は非常に単純な表現を有しており,それを用いて不均質球モデルに対する近似的固有振動数が容易に得られる.それは特に,angular orderの比較的小さな高次のモードに対して有効である.この波線理論的特性方程式の導出は,ノーマル・モード理論に基づいて漸近式を得る方法に比べ,ここで取扱った問題に関して言えば著しく簡単である.","subitem_description_type":"Abstract"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"128770","nameIdentifierScheme":"WEKO"}],"names":[{"name":"小高, 俊一"}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000033026","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":"Odaka, Toshikazu"}],"nameIdentifiers":[{"nameIdentifier":"128769","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":"ji0562001.pdf","filesize":[{"value":"1.9 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0562001.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/33026/files/ji0562001.pdf"},"version_id":"e79f2636-fb50-4fab-a851-0a56337e0c40"}]},"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":"Ray-Theoretical Approach to Frequency Equations of Spheroidal Oscillations of a Spherical Earth with Uniform or Non-Uniform Mantle and Care","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Ray-Theoretical Approach to Frequency Equations of Spheroidal Oscillations of a Spherical Earth with Uniform or Non-Uniform Mantle and Care","subitem_title_language":"en"}]},"item_type_id":"4","owner":"1","path":["4823","4824"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2008-05-30"},"publish_date":"2008-05-30","publish_status":"0","recid":"33026","relation_version_is_last":true,"title":["Ray-Theoretical Approach to Frequency Equations of Spheroidal Oscillations of a Spherical Earth with Uniform or Non-Uniform Mantle and Care"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T04:08:40.928680+00:00"}