政大機構典藏-National Chengchi University Institutional Repository(NCCUR):Item 140.119/85146

English | 正體中文 | 简体中文 | Post-Print筆數 : 27 | Items with full text/Total items : 113648/144635 (79%)
Visitors : 51670646 Online Users : 547

RC Version 6.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.

Scope

please add "double quotation mark" for query phrases to get precise results

please goto advance search for comprehansive author search

Adv. Search

Home ‧ Login ‧ Upload ‧ Help ‧ About ‧ Administer

Goto mobile version

政大機構典藏 > 商學院 > 統計學系 > 學位論文 > Item 140.119/85146

Please use this identifier to cite or link to this item: https://nccur.lib.nccu.edu.tw/handle/140.119/85146

Title:	變數轉換之離群值偵測 Detection of Outliers with Data Transformation
Authors:	吳秉勳 Wu, David
Contributors:	鄭宗記吳秉勳 David Wu
Keywords:	容離值最小中位數穩健迴歸估計值遮蔽效應最小體積橢圓體估計值 Mahalanobis 距離分數統計量鐘乳石圖步進搜尋演算法 Breakdown Point Least Median Square (LMS) Estimator The Masking Effect Minimum Volume Ellipsoid (MVE) Estimator Mahalanobis Distance Score Statistic Stalactite Plot The Forward Search Algorithm
Date:	2001
Issue Date:	2016-04-15 16:10:25 (UTC+8)
Abstract:	在迴歸分析中，當資料中存在很多離群值時，偵測的工作變得非常不容易。在此狀況下，我們無法使用傳統的殘差分析正確地偵測出其是否存在，此現象稱為遮蔽效應(The Masking Effect)。而為了避免此效應的發生，我們利用最小中位數穩健迴歸估計值(Least Median Squares Estimator)正確地找出這些群集離群值，此估計值擁有最大即50﹪的容離值 (Breakdown point)。在這篇論文中，用來求出最小中位數穩健迴歸估計值的演算法稱為步進搜尋演算法 (the Forward Search Algorithm)。結果顯示，我們可以利用此演算法得到的穩健迴歸估計值，很快並有效率的找出資料中的群集離群值；另外，更進一步的結果顯示，我們只需從資料中隨機選取一百次子集，並進行步進搜尋，即可得到概似的穩健迴歸估計值並正確的找出那些群集離群值。最後，我們利用鐘乳石圖(Stalactite Plot)列出所有被偵測到的離群值。 Detecting regression outliers is not trivial when there are many of them. The methods of using classical diagnostic plots sometimes fail to detect them. This phenomenon is known as the masking effect. To avoid this, we propose to find out those multiple outliers by using a highly robust regression estimator called the least median squares (LMS) estimator which has maximal breakdown point. The algorithm in search of the LMS estimator is called the forward search algorithm. The estimator found by the forward search is shown to lead to the rapid detection of multiple outliers. Furthermore, the result reveals that 100 repeats of a simple forward search from a random starting subset are shown to provide sufficiently robust parameter estimators to reveal multiple outliers. Finally, those detected outliers are exhibited by the stalactite plot that shows greatly stable pattern of them.
Description:	碩士國立政治大學統計學系 87354011
Source URI:	http://thesis.lib.nccu.edu.tw/record/#A2002001359
Data Type:	thesis
Appears in Collections:	[統計學系] 學位論文

Files in This Item:

There are no files associated with this item.

All items in 政大典藏 are protected by copyright, with all rights reserved.

社群 sharing

著作權政策宣告 Copyright Announcement

1.本網站之數位內容為國立政治大學所收錄之機構典藏，無償提供學術研究與公眾教育等公益性使用，惟仍請適度，合理使用本網站之內容，以尊重著作權人之權益。商業上之利用，則請先取得著作權人之授權。
The digital content of this website is part of National Chengchi University Institutional Repository. It provides free access to academic research and public education for non-commercial use. Please utilize it in a proper and reasonable manner and respect the rights of copyright owners. For commercial use, please obtain authorization from the copyright owner in advance.

2.本網站之製作，已盡力防止侵害著作權人之權益，如仍發現本網站之數位內容有侵害著作權人權益情事者，請權利人通知本網站維護人員(nccur@nccu.edu.tw)，維護人員將立即採取移除該數位著作等補救措施。
NCCU Institutional Repository is made to protect the interests of copyright owners. If you believe that any material on the website infringes copyright, please contact our staff(nccur@nccu.edu.tw). We will remove the work from the repository and investigate your claim.

DSpace Software Copyright © 2002-2004 MIT & Hewlett-Packard / Enhanced by NTU Library IR team Copyright © - Feedback