{"_buckets": {"deposit": "791a310e-4dc8-4252-b124-e0c152ad496a"}, "_deposit": {"id": "42612", "owners": [], "pid": {"revision_id": 0, "type": "depid", "value": "42612"}, "status": "published"}, "_oai": {"id": "oai:repository.dl.itc.u-tokyo.ac.jp:00042612"}, "item_8_biblio_info_7": {"attribute_name": "\u66f8\u8a8c\u60c5\u5831", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "2013-10", "bibliographicIssueDateType": "Issued"}, "bibliographicVolumeNumber": "CIRJE-F-906", "bibliographic_titles": [{"bibliographic_title": "Discussion paper series. CIRJE-F"}]}]}, "item_8_description_13": {"attribute_name": "\u30d5\u30a9\u30fc\u30de\u30c3\u30c8", "attribute_value_mlt": [{"subitem_description": "application/pdf", "subitem_description_type": "Other"}]}, "item_8_description_5": {"attribute_name": "\u6284\u9332", "attribute_value_mlt": [{"subitem_description": "The problem of estimating the covariance matrix of normal and non-normal distributions is addressed when both the sample size and the dimension of covariance matrix tend to infinity. In this paper, we consider a class of ridge-type estimators which are linear combinations of the unbiased estimator and the identity matrix multiplied by a scalor statistic, and we derive a leading term of their risk functions relative to a quadratic loss function. Within this class, we obtain the optimal ridge-type estimator by minimizing the leading term in the risk approximation. It is interesting to note that the optimal weight is based on a statistic for testing sphericity of the covariance matrix.", "subitem_description_type": "Abstract"}]}, "item_8_description_6": {"attribute_name": "\u5185\u5bb9\u8a18\u8ff0", "attribute_value_mlt": [{"subitem_description": "\u672c\u6587\u30d5\u30a3\u30eb\u306f\u30ea\u30f3\u30af\u5148\u3092\u53c2\u7167\u306e\u3053\u3068", "subitem_description_type": "Other"}]}, "item_8_publisher_20": {"attribute_name": "\u51fa\u7248\u8005", "attribute_value_mlt": [{"subitem_publisher": "\u65e5\u672c\u7d4c\u6e08\u56fd\u969b\u5171\u540c\u30bb\u30f3\u30bf\u30fc"}]}, "item_8_relation_25": {"attribute_name": "\u95a2\u4fc2URI", "attribute_value_mlt": [{"subitem_relation_type_id": {"subitem_relation_type_id_text": "http://www.cirje.e.u-tokyo.ac.jp/research/dp/2013/2013cf906ab.html", "subitem_relation_type_select": "URI"}}]}, "item_8_source_id_10": {"attribute_name": "\u66f8\u8a8c\u30ec\u30b3\u30fc\u30c9ID", "attribute_value_mlt": [{"subitem_source_identifier": "AA11450569", "subitem_source_identifier_type": "NCID"}]}, "item_8_text_21": {"attribute_name": "\u51fa\u7248\u8005\u5225\u540d", "attribute_value_mlt": [{"subitem_text_value": "Center for International Research on the Japanese Economy"}]}, "item_8_text_34": {"attribute_name": "\u8cc7\u6e90\u30bf\u30a4\u30d7", "attribute_value_mlt": [{"subitem_text_value": "Discussion Paper"}]}, "item_8_text_4": {"attribute_name": "\u8457\u8005\u6240\u5c5e", "attribute_value_mlt": [{"subitem_text_value": "Faculty of Economics, University of Tokyo"}, {"subitem_text_value": "Department of Statistics, University of Toronto"}]}, "item_access_right": {"attribute_name": "\u30a2\u30af\u30bb\u30b9\u6a29", "attribute_value_mlt": [{"subitem_access_right": "metadata only access", "subitem_access_right_uri": "http://purl.org/coar/access_right/c_14cb"}]}, "item_creator": {"attribute_name": "\u8457\u8005", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "Kubokawa, Tatsuya"}], "nameIdentifiers": [{"nameIdentifier": "98000", "nameIdentifierScheme": "WEKO"}]}, {"creatorNames": [{"creatorName": "Srivastrava, Muni S."}], "nameIdentifiers": [{"nameIdentifier": "98001", "nameIdentifierScheme": "WEKO"}]}]}, "item_keyword": {"attribute_name": "\u30ad\u30fc\u30ef\u30fc\u30c9", "attribute_value_mlt": [{"subitem_subject": "Covariance matrix", "subitem_subject_scheme": "Other"}, {"subitem_subject": "high dimension", "subitem_subject_scheme": "Other"}, {"subitem_subject": "non-normal distribution", "subitem_subject_scheme": "Other"}, {"subitem_subject": "normal distribution", "subitem_subject_scheme": "Other"}, {"subitem_subject": "ridge-type estimator", "subitem_subject_scheme": "Other"}, {"subitem_subject": "risk function", "subitem_subject_scheme": "Other"}]}, "item_language": {"attribute_name": "\u8a00\u8a9e", "attribute_value_mlt": [{"subitem_language": "eng"}]}, "item_resource_type": {"attribute_name": "\u8cc7\u6e90\u30bf\u30a4\u30d7", "attribute_value_mlt": [{"resourcetype": "technical report", "resourceuri": "http://purl.org/coar/resource_type/c_18gh"}]}, "item_title": "Optimal Ridge-type Estimators of Covariance Matrix in High Dimension", "item_titles": {"attribute_name": "\u30bf\u30a4\u30c8\u30eb", "attribute_value_mlt": [{"subitem_title": "Optimal Ridge-type Estimators of Covariance Matrix in High Dimension"}]}, "item_type_id": "8", "owner": "1", "path": ["9/7435/7436", "62/7433/7434"], "permalink_uri": "http://hdl.handle.net/2261/55626", "pubdate": {"attribute_name": "\u516c\u958b\u65e5", "attribute_value": "2014-01-16"}, "publish_date": "2014-01-16", "publish_status": "0", "recid": "42612", "relation": {}, "relation_version_is_last": true, "title": ["Optimal Ridge-type Estimators of Covariance Matrix in High Dimension"], "weko_shared_id": null}