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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

論星形對立假設下之最大概似比檢定

劉岱玟, LIU,DAI-WEN Unknown Date (has links)
工業統計是應用統計的一大支脈, 而應用統計必須以理論統計為其基礎, 二者之間才 能產生相輔相成的效果。本文即是以工業統計中可能遇到的問題出發, 透過統計理論 的應用, 以期解決部份的問題。 在工業統計的範疇中, 常可遇見星形(STARSHAPED)的假設條件, 本文的研究重點即在 於將數個常態母體平均數相等的檢定, 限定在星形的對立假設條件下進行, 并導出此 檢定統計量在虛無假設與對立假設下之分配情形。同時探討其檢定力函數(POWER FUN CTION)所具備之優良性質, 包括對稱性、遞增性等。最后將此檢定與一般慣用的非限 制性對立假設( 即對立假設無特殊限制條件 )下的檢定作一比較, 以證明前者優於后 者。
2

兩種正則化方法用於假設檢定與判別分析時之比較 / A comparison between two regularization methods for discriminant analysis and hypothesis testing

李登曜, Li, Deng-Yao Unknown Date (has links)
在統計學上,高維度常造成許多分析上的問題,如進行多變量迴歸的假設檢定時,當樣本個數小於樣本維度時,其樣本共變異數矩陣之反矩陣不存在,使得檢定無法進行,本文研究動機即為在進行兩群多維常態母體的平均數檢定時,所遇到的高維度問題,並引發在分類上的研究,試圖尋找解決方法。本文研究目的為在兩種不同的正則化方法中,比較何者在檢定與分類上表現較佳。本文研究方法為以 Warton 與 Friedman 的正則化方法來分別進行檢定與分類上的分析,根據其檢定力與分類錯誤的表現來判斷何者較佳。由分析結果可知,兩種正則化方法並沒有絕對的優劣,須視母體各項假設而定。 / High dimensionality causes many problems in statistical analysis. For instance, consider the testing of hypotheses about multivariate regression models. Suppose that the dimension of the multivariate response is larger than the number of observations, then the sample covariance matrix is not invertible. Since the inverse of the sample covariance matrix is often needed when computing the usual likelihood ratio test statistic (under normality), the matrix singularity makes it difficult to implement the test . The singularity of the sample covariance matrix is also a problem in classification when the linear discriminant analysis (LDA) or the quadratic discriminant analysis (QDA) is used. Different regularization methods have been proposed to deal with the singularity of the sample covariance matrix for different purposes. Warton (2008) proposed a regularization procedure for testing, and Friedman (1989) proposed a regularization procedure for classification. Is it true that Warton's regularization works better for testing and Friedman's regularization works better for classification? To answer this question, some simulation studies are conducted and the results are presented in this thesis. It is found that neither regularization method is superior to the other.
3

跳躍相關風險下狀態轉換模型之選擇權定價:股價指數選擇權實證分析 / Option pricing of a stock index under regime switching model with dependent jump size risks: empirical analysis of the stock index option

林琮偉, Lin, Tsung Wei Unknown Date (has links)
本文使用Esscher轉換法推導狀態轉換模型、跳躍獨立風險下狀狀態轉換模型及跳躍相關風險下狀態轉換模型的選擇權定價公式。藉由1999年至2011年道瓊工業指數真實市場資料使用EM演算法估計模型參數並使用概似比檢定得到跳躍相關風險下狀態轉換模型最適合描述報酬率資料。接著進行敏感度分析得知,高波動狀態的機率、報酬率的整體波動度及跳躍頻率三者與買權呈現正相關。最後由市場驗證可知,跳躍相關風險下狀態轉換模型在價平及價外的定價誤差皆是最小,在價平的定價誤差則略高於跳躍獨立風險下狀態轉換模型。 / In this paper, we derive regime switching model, regime switching model with independent jump and regime switching model with dependent jump by Esscher transformation. We use the data from 1999 to 2011 Dow-Jones industrial average index market price to estimate the parameter by EM algorithm. Then we use likelihood ratio test to obtain that regime switching model with dependent jump is the best model to depict return data. Moreover, we do sensitivity analysis and find the result that the probability of the higher volatility state , the overall volatility of rate of return , and the jump frequency are positively correlated with call option value. Finally, we enhance the empirical value of regime switching model with dependent jump by means of calculating the price error.
4

漲跌停板限制下之股票報酬機率分配

葉宜欣, Yeh, Yi-Shian Unknown Date (has links)
股票市場的報酬率相對於金融市埸是非常重要的,因為其背後的真實機率分配對各種資產定價及選擇權的評價模型都有決定性的影響。本文考慮台灣股票市埸具有漲跌停板的限制來驗證實證中股票報酬機率分配的「厚尾」的現象,希望透過我們的研究能對財務理論在國內金融市埸的應用有更進一步的了解。我們選定了常態分配、對數常態分配及一般化第二種貝它分配 (GB2)來當作是台灣股票報酬率的真實機率分配,以動差法比較再以概似比檢定法(LR test)選出一表現最好的機率分配。由選取的25支國內股票中發現一般化第二種貝它分配 (GB2)可以解釋偏態和峰態對報酬率的影響並且也是概似比檢定法所選出的最適報酬率分配,由此可知一般化第二種貝它分配 (GB2)較為適合作為台灣股票報酬的真實機率分配。

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