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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

馬可夫鏈蒙地卡羅法在外匯選擇權定價的應用

謝盈弘 Unknown Date (has links)
本篇論文以Regime Switching Stochastic Volatility(RSV)作為外匯選擇權市場的波動度模型,採用馬可夫鏈蒙地卡羅法(Markov Chain Monte Carlo)中的GibbS Sampling演算法估計RSV模型的參數,並預測外匯選擇權在RSV模型下的價格。 數值結果方面首先對GibbS Sampling參數估計的結果做討論,再對預測出的選擇權價格與Black and Scholes作比較,最後並提出笑狀波幅與隱含波動度平面的結果。 本研究所得到之結論: 1. RSV模型與MCMC模擬法的組合,具備產生笑狀波幅的能力,提供足夠證據顯示,RSV模型與MCMC演算法所計算出來的選擇權價格,確實反應且捕捉到了市場上選擇權價格所應具備的特色。 2. 本模型能有效解釋期限結構 (Term Stucture of Volatility)、笑狀波幅(Volatility Smile)的現象。 關鍵字:馬可夫鏈蒙地卡羅法、外匯選擇權、貝氏選擇權評價、MCMC、Regime switching Regine change、Gibbs Sampling、currency option、Markov Chain Montec Carlo
2

貝氏曲線同步化與分類 / Bayesian Curve Registration and Classification

李柏宏, Lee,Po- Hung Unknown Date (has links)
函數型資料分析為近年發展的統計方法。函數型資料是在一段特定時間上,我們只在離散的時間點上收集觀測值。例如:氣象觀測站所收集到的每月氣溫、雨量資料,即是一種常見的函數型資料。函數型資料主要有三種特色,共同趨勢性、觀測個體反應強度不同,觀測個體時間特色上的差異。本文研究主要是使用,Brumback與Lindstrom在2004所提出的自模型迴歸族(self-modeling)當作模型架構來處理函數型資料的趨勢性與個體反應強度。而為了處理函數型資料的時間差異性,我們在模型中加入時間轉換函數(time transformation function),處理函數型資料的時間差異性步驟,這個過程稱為同步化。經過同步化的處理後,能幫助研究者更清楚資料的特性。模型中除了時間轉換函數的部份,其餘模型中的參數我們是利用馬可夫鏈蒙地卡羅法中的Gibbs Sampling來進行參數的抽樣,並以取出的抽樣值來估計參數。時間轉換函數的部份,我們使用概似懲罰函數(penalized likelihood function)來估計時間轉換函數的參數部份。由於函數型資料擁有趨勢性,我們預期不同類別的資料,會呈現不同的趨勢性,我們將利用此一特色當做分類上的標準。 關鍵詞:函數型資料分析、曲線同步化、曲線區別分析、馬可夫鏈蒙地卡羅法。 / Functional data are random curves observed in a period of time at discrete time points.They often exhibit a common shape, but with variations in amplitude and phase across curves.To estimate the common shape,some adjustment for synchronization is often made,which is also known as time warping or curve registration.In this thesis,splines are used to model the warping functions and the common shape. Certain parameters are allowed to be random.For the estimation of the random parameters,priors are proposed so that samples from the posteriors can be obtained using Markov chain Monte Carlo methods.For the estimation of non-random parameters, a penalized likelihood approach is used. It is found via simulation studies that for a set of random curves with a common shape,the estimated common shape function looks like the true function up to a location-scale transform,and the curve alignment based on estimated time warping functions looks reasonable.For two groups of random curves which differ in the group common shape functions,synchronization also improves the discrimination between groups in some cases. Key words: functional data analysis,curve registration,curve discrimination,markov chain monte carlo method.
3

貝氏時間與空間統計模式之應用

黃佩櫻 Unknown Date (has links)
本篇論文的目的在介紹階層貝氏之時間與空間統計模式(spatio-temporal model),將此模式應用在疾病地圖的分析,以了解疾病在空間上的分佈狀態與時間趨勢。模型中除了納入時間、空間和年齡的效應外,也包括時間與空間、時間與年齡的交互作用,並考慮到空間相關性(spatial correlation),然後以DIC值(Deviance information criterion)作為模式選取的準則。 本文並以民國88-90年全身紅斑性狼瘡的女性患病人數做為實證分析的資料。配適時間與空間統計模式後,以馬可夫鏈蒙地卡羅法(MCMC)來模擬參數值,估計出各時間、地區、年齡層的對數疾病發生率。由疾病地圖可看出,台灣地區全身紅斑性狼瘡的女性疾病發生率,以20-59歲的年齡層發生率較高,0-19歲的發生率較低。不管在哪一個年齡層,北部和中部地區的發生率都是最高的。時間趨勢方面,88-90年整體疾病發生率有遞減的趨勢,60歲以上的發生率也是遞減的趨勢。但在部分地區,則有發生率遞增的趨勢。 / In this study, we introduce the spatio-temporal model in a hierarchical Bayesian framework and use disease maps to display the spatial patterns and the temporal trends of disease. A special feature of the model is the inclusion of spatial correlations used to examine spatial effects relative to both regional and regional changes over time by group. Then, we use deviance information criterion (DIC) to compare complex hierarchical models. The methodology is illustrated by an analysis of female Systemic Lupls Erythematosus (SLE) morbidity data in Taiwan during the period 1999-2001.The model inference is implemented using Markov chain Monte Carlo method. The outcomes of the practical analysis appear that the higher morbidity rate occurs in 20-year and 40-year period. No matter what age group, the morbidity rate is highest in the north and the middle of Taiwan. Furthermore, the morbidity rate decreases with respect to year as well as over the 60-year period but it increases in some places.
4

用馬可夫鏈蒙地卡羅法估計隨機波動模型:台灣匯率市場的實證研究

賴耀君, Lai,Simon Unknown Date (has links)
針對金融時序資料變異數不齊一的性質,隨機波動模型除了提供於ARCH族外的另一選擇;且由於其設定隱含波動本身亦為一個隨機波動函數,藉由設定隨時間改變且自我相關的條件變異數,使得隨機波動模型較ARCH族來得有彈性且符合實際。傳統上處理隨機波動模型的參數估計往往需要面對到複雜的多維積分,此問題可藉由貝氏分析裡的馬可夫鏈蒙地卡羅法解決。本文主要的探討標的,即在於利用馬可夫鏈蒙地卡羅法估計美元/新台幣匯率隨機波動模型參數。除原始模型之外,模型的擴充分為三部分:其一為隱含波動的二階自我回歸模型;其二則為藉由基本模型的修改,檢測匯率市場上的槓桿效果;最後,我們嘗試藉由加入scale mixture的方式以驗證金融時序資料中常見的厚尾分配。

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