{"_buckets": {"deposit": "3ede4718-92b3-4ab6-8834-81905def450f"}, "_deposit": {"id": "5844", "owners": [1], "pid": {"revision_id": 0, "type": "depid", "value": "5844"}, "status": "published"}, "_oai": {"id": "oai:nied-repo.bosai.go.jp:00005844", "sets": []}, "author_link": [], "item_10001_biblio_info_7": {"attribute_name": "書誌情報", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "1981", "bibliographicIssueDateType": "Issued"}, "bibliographicIssueNumber": "2", "bibliographicPageEnd": "240", "bibliographicPageStart": "223", "bibliographicVolumeNumber": "34", "bibliographic_titles": [{"bibliographic_title": "地震 第２輯", "bibliographic_titleLang": "ja"}, {"bibliographic_title": "Zisin (Journal of the Seismological Society of Japan. 2nd ser.)", "bibliographic_titleLang": "en"}]}]}, "item_10001_description_5": {"attribute_name": "抄録", "attribute_value_mlt": [{"subitem_description": "Recent increasing amount of microearthquake data requires urgent necessity of accurate automatic handling in on- and/or off-line processings. Although several techniques have been proposed for automatic detection of P arrivals, those for S onset times are still less developed. This is mainly because the signal to noise ratios around S arrivals are usually very low, in other words, the variations of amplitude and frequency are not so conspicuous as in the case of P waves. This paper aims to show a practical algorithm for the detection of S arrivals.\u003cbr\u003eFirst, the particle motions of P and S waves are investigated based on the rotary spectra from two components of seismograms. It is found that the information of particle motions can improve noticeably the detection accuracies of P and S onset times and can be effectively used as a powerful tool of detection, especially when the signal to noise ratios are low. The direct usage of particle motion is too tedious to be adopted in practical automatic processing. It is proposed, therefore, to apply the 2-dimensional autoregressive model (AR model) to two horizontal components of seismograms. The parameters in this model, involve implicitly the information on amplitude and frequency as well as particle motion. An algorithm using the log-likelihood ratio function of 2-dimensional AR model is tested for actual microearthquake data. It is proved that 2-dimensional model based on two components of seismogram is much more powerful for the detection of S onset times than 1-dimensional one from a single component.\u003cbr\u003eThe differences between S onset times by eyes and computer are examined for data of which S-P times are from 2 to 30 seconds. They are within ±0.1 seconds for 43 (86%) out of 50 events and within ±0.15 seconds for 47 data (94%). The bias is 0.02 seconds, which is of no significance. This algorithm is practical available in off-line processing, although it needs too long computer time for real time one.", "subitem_description_language": "en", "subitem_description_type": "Other"}]}, "item_10001_publisher_8": {"attribute_name": "出版者", "attribute_value_mlt": [{"subitem_publisher": "公益社団法人 日本地震学会", "subitem_publisher_language": "ja"}, {"subitem_publisher": "SEISMOLOGICAL SOCIETY OF JAPAN", "subitem_publisher_language": "en"}]}, "item_10001_relation_14": {"attribute_name": "DOI", "attribute_value_mlt": [{"subitem_relation_type_id": {"subitem_relation_type_id_text": "10.4294/zisin1948.34.2_223"}}]}, "item_10001_source_id_9": {"attribute_name": "ISSN", "attribute_value_mlt": [{"subitem_source_identifier": "1883-9029", "subitem_source_identifier_type": "EISSN"}]}, "item_creator": {"attribute_name": "著者", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "森田 裕一", "creatorNameLang": "ja"}, {"creatorName": "MORITA Yuichi", "creatorNameLang": "en"}]}, {"creatorNames": [{"creatorName": "浜口 博之", "creatorNameLang": "ja"}, {"creatorName": "HAMAGUCHI Hiroyuki", "creatorNameLang": "en"}]}]}, "item_title": "2次元自己回帰過程によるS波初動の自動検測", "item_titles": {"attribute_name": "タイトル", "attribute_value_mlt": [{"subitem_title": "2次元自己回帰過程によるS波初動の自動検測", "subitem_title_language": "ja"}, {"subitem_title": "Automatic Detection of S-Onset Times Using Two Dimensional Autoregressive Model Fitting", "subitem_title_language": "en"}]}, "item_type_id": "40001", "owner": "1", "path": ["1670839190650"], "permalink_uri": "https://nied-repo.bosai.go.jp/records/5844", "pubdate": {"attribute_name": "PubDate", "attribute_value": "2023-03-30"}, "publish_date": "2023-03-30", "publish_status": "0", "recid": "5844", "relation": {}, "relation_version_is_last": true, "title": ["2次元自己回帰過程によるS波初動の自動検測"], "weko_shared_id": -1}