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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.
71

財政整頓的不對稱效果 - 追蹤資料分量迴歸之應用 / Asymmetric effects of fiscal consolidation - an application of panel data quantile regression

陳彥凱, Chen, Yen-Kai Unknown Date (has links)
全球金融危機之後,在許多國家嚴重赤字之下,各界皆相當關心財政整頓效果。本文參考 Lin(2016) 的三階段方法估計動態追蹤資料分量迴歸,並使用敘事法 (narrative approach) 所建構的財政整頓衝擊變數,分析 17 個 OECD 國家 1978-2007 年跨國追蹤資料,探討財政整頓對經濟成長的影響效果。實證結果顯示財政整頓對經濟成長為負向影響,實施財政整頓會抑制產出,對一國經濟造成損害,且在經濟情勢不佳時,該負向效果更明顯。
72

單一資產與複資產的美式選擇權之評價 / The Valuation of American Options on Single Asset and Multiple Assets

劉宣谷, Liu, Hsuan Ku Unknown Date (has links)
過去的三十年間由於評價美式選擇權所產生的自由邊界問題已經有相當的研究成果。本論文將證明自由邊界問題的解為遞增函數。更進一步提出自由邊界凹性的嚴謹証明。利用我們的結論可以得知美式選擇權的最佳履約邊界對時間而言為嚴格遞減的凹函數。這個結果對可用來求導最佳履約邊界的漸近解。 對於美式交換選擇權,我們將其自由邊界問題轉換成單變數的積分方程,同時提供一個永續型美式交換選擇權的評價公式。對於有限時間的美式交換選擇權的最佳履約邊界,我們將提供一個接近到期日的漸近解並發展一個數值方法求其數值解。數值計算的結果顯示漸近解在接近到期日時與數值解非常接近。 對於評價美式選擇權,我們提出使用混合整數非線性規劃(MINLP)的模型,這個模型的最佳解同時提供賣方的完全避險策略、買方的最佳交易策略與美式選擇權的公平價格。因為求算MINLP模型的解需耗用大量的計算時間,我們證明此模型和其非線性規劃的寬鬆問題有相同的最佳解,所以只需求算寬鬆問題即可。觀察數值結果亦顯示非線性規劃的寬鬆問題可以大幅的降低計算的時間。此外,當市場的價格低於公平價格時,我們提出一個最小化賣方期望損失的數學規劃模型,此模型的解提供賣方最小化其期望損失的避險策略。 / In the past three decades, a great deal of effort has been made on solving the free boundary problem (FBP) arising from American option valuation problems. In this dissertation, we show that the solutions, the price and the free boundary, of this FBP are increasing functions. Furthermore, we provide a rigorous verification that the free boundary of this problem is concave. Our results imply that the optimal exercise boundary of an American call is a strictly decreasing concave function of time. These results will provide a useful information to obtain an asymptotic formula for the optimal exercise boundary. For pricing of American exchange options (AEO), we convert the associated FBP into a single variable integral equation (IE) and provide a formula for valuating the perpetual AEO. For the finite horizon AEO, we propose an asymptotic solution as time is near to expiration and develop a numerical method for its optimal exercise boundary. Compared with the computational results, the values of our asymptotic solution are close to the computational results as time is near to expiration. For valuating American options, we develop a mixed integer nonlinear programming (MINLP) model. The solution of the MINLP model provides a hedging portfolio for writers, the optimal trading strategy for buyers, and the fair price for American options at the same time. We show that it can be solved by its nonlinear programming (NLP) relaxation. The numerical results reveal that the use of NLP relaxation reduces the computation time rapidly. Moreover, when the market price is less than the fair price, we propose a minimum expected loss model. The solution of this model provides a hedging strategy that minimizes the expected loss for the writer.
73

認購權證與標的股票間之線性與非線性因果關係─台灣實證 / Linear and nonlinear dynamics between stock and warrant markets in Taiwan Stock Exchange

鄭明宗, Jeng, Ming-Tzung Unknown Date (has links)
In this study, linear and nonlinear Granger causality tests are used to examine the dynamics, including return to return and volume to volume relationships, between warrants and their underlying stocks in Taiwan Stock Exchange (TSEC). Results of previous studies are mixed and they only focus on linear relationship between the two markets. Here we take nonlinear relationship into consideration to assist in investigating what the direction of information flow is. We use intraday five-minute high frequency data and the result tells that, overall, for both return to return and volume to volume relations, there is bidirectional but asymmetry linear causality and weak unidirectional nonlinear causality from stock to warrant market between these two markets. Combining the linear and nonlinear results we conclude that the direction of information flow is mainly from stock market to warrant market.
74

遺漏值存在時羅吉斯迴歸模式分析之研究 / Logistic Regression Analysis with Missing Value

劉昌明, Liu, Chang Ming Unknown Date (has links)
75

模糊線性迴歸之研究

趙家慶 Unknown Date (has links)
使用傳統迴歸的方式對未知事物做預測,往往不能夠精準的做出結論,縱使在相同的條件下實際去操作,也很難得到相同的結果,因此模糊數概念的建立,並運用在迴歸分析上更能有效描述預測結果的不確定性。然而模糊線性迴歸(Fuzzy Linear Regression)在利用最小平方法處理問題時,往往過於著重在模糊區間的中心與分展度上,而忽略了描述資料的模糊性,使得隸屬度函數(membership function)的功能受到相當大的限制。本文在D'Urso和Gastaldi(2000)所提出的雙重模糊線性迴歸(doubly fuzzy linear regression)模型架構下,利用Yang和Ko(1996)在LR空間下所定義模糊數間的距離公式,導出能反映隸屬度函數的最小平方估計,並引進一些傳統迴歸中常用來偵測離群值(outlier)與具影響力觀察值(influence observation)的概念與技巧,應用在模糊線性迴歸資料的偵測上。
76

產業相依下的停電風險分析 / Risk Analysis of Interdependent Industries

林佩琪 Unknown Date (has links)
行政院國土安全辦公室(2010)於國家關鍵基礎設施防護計畫中,將我國的關鍵基礎設施分為8大部門。本研究將對此8大部門關鍵基礎建設進行經濟面的分析比較,將此8大部門關鍵基礎建設對應到產業關聯表中18個產業,應用需求面投入產出停轉模型比較各關鍵基礎產業對整體產業需求的依賴程度以及說明各關鍵基礎產業如何相互影響。此外,由於我國關鍵基礎防護優先順序第一者為能源,因此進一步以電力為代表能源,分析近年來因天然災害衝擊和產業需求增加而面臨供應不足且對整體產業需求依賴程度排名第一的電力及蒸汽產業,應用線性規劃投入產出停轉模型模擬在電力供應短缺之下,若同時考慮極小化整體經濟損失與民生基本需求的電力配置策略。在本研究中,維持民生基本需求是假設各關鍵基礎產業其最終需求變動不大於50%。 需求面投入產出停轉模型是Leontief投入產出模型的線性轉換,主要透過分配係數進行衝擊的傳遞。若某關鍵基礎產業具有以下兩特性,當各產業投入需求皆減少10%,此關鍵基礎產業的停轉性則大,可藉此說明某關鍵基礎產業對整體產業需求的依賴程度:一、產出主要當作中間投入使用;二、為一集中分配型產業供應鏈的重要上游產業,即此產業供應鏈之產出分配集中,且主要下游產業產出皆主要當中間投入使用。其中依賴程度前三名依序為電力及蒸汽、自來水、石油化工原料。若細部分析各關鍵基礎產業停轉性的主要來源,可了解關鍵基礎產業間明顯的需求依賴關係。而在模擬電力供應不足時的電力配置策略方面,產品單位內含電力投入減少對整體經濟造成的停轉性越小者優先分擔供電缺口。其中若僅以極小化整體經濟損失為目標,將使部分關鍵基礎產業的最終需求完全無法被滿足,而加入維持民生基本需求的考量儘管會提高整體經濟損失且分擔供電缺口的產品增加,但與未進行電力配置的結果相比,仍有效減少42.5%的整體經濟損失,同時更貼近社會需求與期待。 關鍵詞:限制用電、關鍵基礎產業、需求面投入產出停轉模型、線性規劃投入產出停轉模型、風險分析
77

廣義線性模式下處理比較之最適設計 / Optimal Designs for Treatment Comparisons under Generalized Linear Models

何漢葳, Ho, Han Wei Unknown Date (has links)
本研究旨在建立廣義線性模式下之D-與A-最適設計(optimal designs),並依不同處理結構(treatment structure)分成完全隨機設計(completely randomized design, CRD)與隨機集區設計(randomized block design, RBD)兩部分探討。 根據完全隨機設計所推導出之行列式的性質與理論結果,我們首先提出一個能快速大幅限縮尋找D-最適正合(exact)設計範圍的演算法。解析解的部分,則從將v個處理的變異數分為兩類出發,建立其D-最適近似(approximate)設計,並由此發現 (1) 各水準對應之樣本最適配置的上下界並非與水準間不同變異有關,而是與有多少處理之變異相同有關;(2) 即使是變異很大的處理,也必須分配觀察值,始能極大化行列式值。此意味著當v較大時,均分應不失為一有效率(efficient)的設計。至於正合設計,我們僅能得出某一處理特別大或特別小時的D-最適設計,並舉例說明求不出一般解的原因。 除此之外,我們亦求出當三個處理的變異數皆不同時之D-最適近似設計,以及v個處理皆不同時之A-最適近似設計。 至於最適隨機集區設計的建立,我們的重點放在v=2及v=3的情形,並假設集區樣本數(block size)為給定。當v=2時,各集區對應之行列式值不受其他集區的影響,故僅需依照完全隨機設計之所得,將各集區之行列式值分別最佳化,即可得出D-與A-最適設計。值得一提的是,若進一步假設各集區中兩處理變異的比例(>1)皆相同,且集區大小皆相同,則將各處理的「近似設計下最適總和」取最接近的整數,再均分給各集區,其結果未必為最適設計。當v=3時,即使只有2個集區,行列式也十分複雜,我們目前僅能證明當集區內各處理的變異相同時(不同集區之處理變異可不同),均分給定之集區樣本數為D-最適設計。當集區內各處理的變異不全相同時,我們僅能先以2個集區為例,類比完全隨機設計的性質,舉例猜想當兩集區中處理之變異大小順序相同時,各處理最適樣本配置的多寡亦與變異大小呈反比。由於本研究對處理與集區兩者之效應假設為可加,因此可合理假設集區中處理之變異大小順序相同。 / The problem of finding D- and A-optimal designs for the zero- and one-way elimination of heterogeneity under generalized linear models is considered. Since GLM designs rely on the values of parameters to be estimated, our strategy is to employ the locally optimal designs. For the zero-way elimination model, a theorem-based algorithm is proposed to search for the D-optimal exact designs. A formula for the construction of D-optimal approximate design when values of unknown parameters are split into two, with respective sizes m and v-m, are derived. Analytic solutions provided to the exact counterpart, however, are restricted to the cases when m=1 and m=v-1. An example is given to explain the problem involved. On the other hand, the upper bound and lower bound of the optimal number of replicates per treatment are proved dependent on m, rather than the unknown parameters. These bounds imply that designs having as equal number of replications for each treatment as possible are efficient in D-optimality. In addition, a D-optimal approximate design when values of unknown parameters are divided into three groups is also obtained. A closed-form expression for an A-optimal approximate design for comparing arbitrary v treatments is given. For the one-way elimination model, our focus is on studying the D-optimal designs for v=2 and v=3 with each block size given. The D- and A-optimality for v=2 can be achieved by assigning units proportional to square root of the ratio of two variances, which is larger than 1, to the treatment with smaller variance in each block separately. For v=3, the structure of determinant is much more complicated even for two blocks, and we can only show that, when treatment variances are the same within a block, design having equal number of replicates as possible in each block is a D-optimal block design. Some numerical evidences conjecture that a design satisfying the condition that the number of replicates are inversely proportional to the treatment variances per block is better in terms of D-optimality, as long as the ordering of treatment variances are the same across blocks, which is reasonable for an additive model as we assume.
78

線性動態模糊影像之研究 / A study of linear motion blurred image

吳諭忠, Wu, Yu Chung Unknown Date (has links)
生活中在使用相機時,由於機器晃動或物體移動所造成的模糊影像時常可見。當影像模糊的成因是影像曝光時間內相機與拍攝物體相對線性移動時,則我們稱為線性動態模糊。理論上,模糊影像可以表示成原始影像與點擴散函數的旋積,本文的研究重點為點擴散函數中模糊參數的估計,雷登轉換將被運用在此問題上。我們首先介紹兩個現有方法,我們將探討這些方法中用來消除雜訊的步驟之適用性及必要性。另一方面,在模糊參數的估計過程中,我們在雷登轉換加入圓限制以及採用移動平均法。我們透過實驗證實,本篇提出的方法可以獲得更準確的估計結果以及更好的模糊影像還原效果。 / Nowadays, collecting a digital image becomes convenient and low-cost due to rapid progress in digital camera technology. Blurred images frequently appear because of camera shake or moving objects. There are several different types of blur. When the blur is caused by the linear motion between the object and the camera during the light exposure, it’s called a linear motion blur. Mathematically, a blurred image is expressed as a convolution of a point spread function and the original image. Our study considers Radon transform for the estimation of the point spread function. To improve the existing methods, a circle restriction and the moving average method are applied in the estimating procedure. Through intensive experiments, the proposed method is found enable to produce more accurate estimation and better performance in image restoration.
79

測驗等值法之探討及其在心理測驗上之應用

黃廲嬌, HUANG,LI-JIAO Unknown Date (has links)
本研究主要目的: 1、探討測驗等值法的意義與方法。 2、垂直等值法檢驗羅桑二氏非語文智力測驗層次BCDE試題排列。 3、水平等值法建立瑞文氏非文字推理測驗(SPM )與羅桑二氏非語文智力測驗層次 B 等值分數。 4、探討IRT 中Rasch model 對傳統等值方法改善心理測驗之成效。 本研究樣本取自台北市立五常國民小學四、五、六年級學生,依年級各隨機抽取五個 班級,以及台北市立五常國民中學二年級學生,依班級人數比率隨機抽取百名研研究 工具包括羅桑二氏非語文智力測驗層次BCDE和瑞文氏非文字推理測驗(SPM )。 統計分析: 1、Wright.B.D以Rasch s logislic model發展之MSCALE, 估計試題難度及受試者能 力, 並考驗資料與模式之適合度。 2、因素分析檢證測驗是否符合Rasch 單一向度之假設。 3、迴歸分析線性、百分等值方法。
80

一個極值問題在抽樣理論上的應用及其程式解

田益誠, TIAN, YI-CHENG Unknown Date (has links)
在統計學上我們經常會遭遇到如下的問題: minimze subject to 其中 和C都是已知。 上述非線性規劃(NONLINEAR PROGRAMING)問題的最佳解,是相當複雜的,以致於我 們無法用簡單的式子,將其解明確的表示出來。 RAO-GHANGURDE (1972)在“從有限母體抽樣的貝氏最佳解”這一篇文章中,對 這種非線性規劃問題,提出一個反覆演算的解法,來解決這類問題,由於,我們無法 看出其演算法的立論根據何在,收斂結果的精確性有多高,於是,本文在k=2及k =3的情形下,由直覺的幾何觀點,提出了另一個求最佳解的方法,來驗證RAO-GHAN GURED 反覆演算法的類確性。 最後,本論文將上述非線性規劃問題的解法,應用到下面兩個例子上: (a)在 COCHRAN的“抽樣技巧”( SAMPLING TECHNIQUES)這一本書裡,有關雙重 抽樣(DOUBLE SAMPLING )的理論中,也遭遇到要解決這一類問題,但由他的公式, 所計算出來的解,並不一定會萬足所需要的限制條件。 (b)在SMITH-SEDRASK (1982)的“推估魚群年齡成份的貝氏最佳解“和JINN -SMITH-SEDRASK(1987)的“推估魚群年齡成份的貝氏最佳雙重抽樣”這兩篇的 文章中,同樣的也遭遇到這一類的問題。

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