{"created":"2023-07-27T06:50:19.047715+00:00","id":43051,"links":{},"metadata":{"_buckets":{"deposit":"dc69000c-84a4-490c-a92b-9d7ee328df2b"},"_deposit":{"created_by":18,"id":"43051","owners":[18],"pid":{"revision_id":0,"type":"depid","value":"43051"},"status":"published"},"_oai":{"id":"oai:kanazawa-u.repo.nii.ac.jp:00043051","sets":["2812:2813:2839"]},"author_link":["69253","69254"],"item_9_biblio_info_8":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1995-03","bibliographicIssueDateType":"Issued"},"bibliographicPageStart":"153p.","bibliographicVolumeNumber":"1993-1994","bibliographic_titles":[{"bibliographic_title":"平成6(1994)年度 科学研究費補助金 一般研究(C) 研究成果報告書"},{"bibliographic_title":"1994 Fiscal Year Final Research Report","bibliographic_titleLang":"en"}]}]},"item_9_creator_33":{"attribute_name":"著者別表示","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{}],"nameIdentifiers":[{},{}]}]},"item_9_description_21":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"本研究は2ケ年にわたり、次のような研究課題を設定し研究を行なった。\n(1)大電力電磁波パルス発生装置および受信装置の改良\n(2)超低周波電磁波の地中伝搬特性の理論解析\n(1)に関しては、従来の装置では、地下からの反射波を検出する際にサーチコイルによる受信波形をディジタルオシロスコープにより記録していたが、連続的に取得できる時間に制限があったため商用周波数程度のノイズの除去が困難であった。本研究では、2chの波形をそれぞれ12ビット、60kHzでサンプリングし、64kBytesのメモリに書き込むことにより、約500msecの連続データ取得が可能な波形捕捉受信機の開発を行なった。また、温泉試掘坑などでの将来の実験に対応できるように、3気圧耐水のサーチコイルセンサを開発した。一方で、従来の送信装置では高速スイッチングが困難であったトランジスタ利用のSIT(静電誘導トランジスタ)ドライバ回路をダイオード・ドライバに改良し、高速な送信パルススイッチング(〜100kHz)を可能にした。\n(2)に関しては、ヘルツベクトルのSommerfeld積分展開を用いて、地表面に置かれた水平ループアンテナから放射される球面電磁波の水平層状不均質地下媒質における伝搬を解析した。自由空間、地下媒質を含む2層、3層モデルに対するモデル計算を行ない、放射電磁界の地下における減衰を評価した。一方、上のような理論的解析では厳密にモデル化して計算することが困難な任意形状の不均質地下媒質における電磁波伝搬を解析するために、新たにMaxwellの方程式を時空間で差分化して直接解き進めるコンピュータ・シミュレーションの開発に着手した。1次元および2次元のコードを作成し、簡単なモデルで平面波や円筒波の伝搬をシミュレートし、作成したプログラムの妥当性の評価を行なった。\n今後は、製作された大電力パルス発生装置および受信装置を用いて実際に地中伝搬実験を行ない、装置の性能を評価するとともに、受信データと理論計算との比較を行なって大電力電磁パルスによる地中探査の可能性を探っていく。 ","subitem_description_type":"Abstract"},{"subitem_description":"This research has been carried out over two years on the basis of following two categories :\n(1) Improvement of a high-power VLF electromagnetic pulse generator and a signal reception system\n(2) Theoretical analysis of VLF propagation in the underground\nAs for the item (1) , we have developed a wave form capture receiver which can memorize two channels of received waveforms over 500 msec at the 12-bit accuracy and at the sampling frequency of 60kHz, to reduce the effect of commercial power line noise. A waterproof search coil has been developed which will be used for signal detection even in the water in the underground. We have replaced a transistor circuit driving SIT for high-power radiation, with a diode circuit to improve high-frequency (up to 100kHz) response of pulse transmission.\nAs for the item (2) , a Sommerfeld integration method has been developed to calculate spherical electromagnetic fields in the underground which is radiated by a horizontal loop antenna placed on the ground surface. Using this, we have evaluated attenuation of a radiated VLF wave in a horizontally stratified underground and also intensity of reflected waves from an object in the underground on the basis of the physical optics approximation. On the other hand, one-and two-dimensional computer simulation codes have been developed to analyze wave propagation in a more complicated underground medium, which conventional theoretical calculations fail to deal with.","subitem_description_type":"Abstract"}]},"item_9_description_22":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"研究課題/領域番号:05650350, 研究期間(年度):1993-1994","subitem_description_type":"Other"},{"subitem_description":"出典：「超低周波大振幅電磁パルス波の地中伝搬実験」研究成果報告書　課題番号05650350\n  (KAKEN：科学研究費助成事業データベース（国立情報学研究所）)\n　　　本文データは著者版報告書より作成","subitem_description_type":"Other"}]},"item_9_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.24517/00049398","subitem_identifier_reg_type":"JaLC"}]},"item_9_publisher_17":{"attribute_name":"公開者","attribute_value_mlt":[{"subitem_publisher":"金沢大学工学部"}]},"item_9_relation_28":{"attribute_name":"関連URI","attribute_value_mlt":[{"subitem_relation_name":[{"subitem_relation_name_text":"https://kaken.nii.ac.jp/search/?qm=50019775"}],"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://kaken.nii.ac.jp/search/?qm=50019775","subitem_relation_type_select":"URI"}},{"subitem_relation_name":[{"subitem_relation_name_text":"https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05650350/"}],"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05650350/","subitem_relation_type_select":"URI"}},{"subitem_relation_name":[{"subitem_relation_name_text":"https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-05650350/056503501994kenkyu_seika_hokoku_gaiyo/"}],"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-05650350/056503501994kenkyu_seika_hokoku_gaiyo/","subitem_relation_type_select":"URI"}}]},"item_9_version_type_25":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_ab4af688f83e57aa","subitem_version_type":"AM"}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-12-21"}],"displaytype":"detail","filename":"TE-PR-NAGANO-I-kaken 1995-153p.pdf","filesize":[{"value":"5.3 MB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"TE-PR-NAGANO-I-kaken 1995-153p.pdf","url":"https://kanazawa-u.repo.nii.ac.jp/record/43051/files/TE-PR-NAGANO-I-kaken 1995-153p.pdf"},"version_id":"60b742f9-2a08-487d-804f-51445ecba59a"}]},"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":"research report","resourceuri":"http://purl.org/coar/resource_type/c_18ws"}]},"item_title":"超低周波大振幅電磁パルス波の地中伝搬実験","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"超低周波大振幅電磁パルス波の地中伝搬実験"},{"subitem_title":"Propagation Experiment of VLF Electromagnetic Pulses in the Uuderground for Development of Deep Earth Radar","subitem_title_language":"en"}]},"item_type_id":"9","owner":"18","path":["2839"],"pubdate":{"attribute_name":"公開日","attribute_value":"2017-12-21"},"publish_date":"2017-12-21","publish_status":"0","recid":"43051","relation_version_is_last":true,"title":["超低周波大振幅電磁パルス波の地中伝搬実験"],"weko_creator_id":"18","weko_shared_id":-1},"updated":"2023-07-27T14:53:13.769957+00:00"}