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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

貝氏雙相抽樣中魚群第一相樣本數的選取

江秉良 Unknown Date (has links)
Simth and Sedransk(1982)採用雙相抽樣的技術推估魚群年齡層的分布,並且在總成本給定的情形下,尋求使事後之前期望損失函數最小的一組最適第二相樣本數。由於期望損失函數過於複雜,而不易於計算處理,所以,他們考慮了一個較為簡單的近似事後之前期望損失函數,由此導出了近似的最適第二相樣本數之公式解。其後Jinn, Sedransk and Simth(1987)繼續探討選取最適第一相樣本數的問題。由於過程中的運算龐大複雜而無法導出公式解,因此Jinn, Sedransk and Simth便提出了近似法和電腦模擬法來解決最適第一相樣本數選取的問題。近似法中仍須使用程序曲折龐雜的演算法以求解,而電腦模擬法則更是必須先執行多次繁複的模擬抽樣後,再以演算法求解;雖然以此所得的解較為精準,但步驟仍難脫於繁瑣複雜。本文中,我們分別就給定各層抽樣率和比例抽樣的情況下,提出了如何藉由簡易的計算便可求得第一相樣本數粗估值的方法。
2

藥劑生體可用及相等性在兩個單尾檢定下樣本數之研究 / Sample Size Determination for the Two One-Sided Tests Procedure in Bioavailability/Bioequivalence

吳嘉翰, Wu, Chia-Han Unknown Date (has links)
藥劑生體可用及相等試驗,對於藥品的研發佔有非常重要之地位.如何在各種交叉實驗設計中選取適當的樣本,以達到我們要求的檢測能力,是本文的主要目的.Liu and chow(1992a)根據Schuirmann(1987)的區間假設檢定以正負20決策準則,針對二乘二交叉實驗設計,提出了一個簡易的樣本數計算方法.本文將對高階交叉實驗設計之樣本數計算方法,做進一步的研究.
3

在不同實驗設計下藥物個體生體相等性檢定力之比較

董雅萍 Unknown Date (has links)
傳統上,判定一種學名藥(generic drug)與原廠藥(innovator drug)是否具有生體相等性所常用的統計方法為:比較兩種藥物的生體可用相對值(relative bioavailability)的母體平均數是否相等,此即所謂的平均生體相等性(average bioequivalence)。然而就兩種藥物可互用的觀點而言,似乎更需要考慮的是每位受測個體在服用藥物後,不同藥物在個體內反應的差異性,因此 Anderson and Hauck (1990)提出個體生體相等性(individual bioequivalence)的觀點。 本文採 Schall (1995)所建議的判定準則來作為評估一種學名藥與原廠藥是否具有個體生體相等性的依據。內容重點為透過模擬(simulation)實驗的方式,對判定藥物為個體生體相等性的檢定力(power)作一評比,研究的項目有:(1)檢定力在不同交叉實驗設計(crossover design)下表現的異同;(2)檢定力在不同參數組合情況下表現的趨勢;(3)樣本數(sample size)對檢定力的影響。 / Conventionally, that a generic drug and an innovator drug are regarded as having the same treatment effects is based on the concept of average bioequivalence,i.e., that average responses between individuals on the two formulations are similar. Anderson and Hauck (1990) argued that it was not sufficient to expect that an individual patient would response similarly to the two formulations. The thought has received a lot of attention lately, and quite a few methods have been proposed to deal with the issue of the individual bioequivalence. According to the "unified" approach proposes by Schall (1995), a simulation study on power to declare bioequivalence and coverage probability of confidence intervals is carried out here to compare their performance under different experimental designs.
4

自變數有誤差的邏輯式迴歸模型:估計、實驗設計及序貫分析 / Logistic regression models when covariates are measured with errors: Estimation, design and sequential method

簡至毅, Chien, Chih Yi Unknown Date (has links)
本文主要在探討自變數存在有測量誤差時,邏輯式迴歸模型的估計問題,並設計實驗使得測量誤差能滿足遞減假設,進一步應用序貫分析方法,在給定水準下,建立一個信賴範圍。 當自變數存在有測量誤差時,通常會得到有偏誤的估計量,進而在做決策時會得到與無測量誤差所做出的決策不同。在本文中提出了一個遞減的測量誤差,使得滿足這樣的假設,可以證明估計量的強收斂,並證明與無測量誤差所得到的估計量相同的近似分配。相較於先前的假設,特別是證明大樣本的性質,新增加的樣本會有更小的測量誤差是更加合理的假設。我們同時設計了一個實驗來滿足所提出遞減誤差的條件,並利用序貫設計得到一個更省時也節省成本的處理方法。 一般的case-control實驗,自變數也會出現測量誤差,我們也證明了斜率估計量的強收斂與近似分配的性質,並提出一個二階段抽樣方法,計算出所需的樣本數及建立信賴區間。 / In this thesis, we focus on the estimate of unknown parameters, experimental designs and sequential methods in both prospective and retrospective logistic regression models when there are covariates measured with errors. The imprecise measurement of exposure happens very often in practice, for example, in retrospective epidemiology studies, that may due to either the difficulty or the cost of measuring. It is known that the imprecisely measured variables can result in biased coefficients estimation in a regression model and therefore, it may lead to an incorrect inference. Thus, it is an important issue if the effects of the variables are of primary interest. When considering a prospective logistic regression model, we derive asymptotic results for the estimators of the regression parameters when there are mismeasured covariates. If the measurement error satisfies certain assumptions, we show that the estimators follow the normal distribution with zero mean, asymptotically unbiased and asymptotically normally distributed. Contrary to the traditional assumption on measurement error, which is mainly used for proving large sample properties, we assume that the measurement error decays gradually at a certain rate as there is a new observation added to the model. This kind of assumption can be fulfilled when the usual replicate observation method is used to dilute the magnitude of measurement errors, and therefore, is also more useful in practical viewpoint. Moreover, the independence of measurement error and covariate is not required in our theorems. An experimental design with measurement error satisfying the required degenerating rate is introduced. In addition, this assumption allows us to employ sequential sampling, which is popular in clinical trials, to such a measurement error logistic regression model. It is clear that the sequential method cannot be applied based on the assumption that the measurement errors decay uniformly as sample size increasing as in the most of the literature. Therefore, a sequential estimation procedure based on MLEs and such moment conditions is proposed and can be shown to be asymptotical consistent and efficient. Case-control studies are broadly used in clinical trials and epidemiological studies. It can be showed that the odds ratio can be consistently estimated with some exposure variables based on logistic models (see Prentice and Pyke (1979)). The two-stage case-control sampling scheme is employed for a confidence region of slope coefficient beta. A necessary sample size is calculated by a given pre-determined level. Furthermore, we consider the measurement error in the covariates of a case-control retrospective logistic regression model. We also derive some asymptotic results of the maximum likelihood estimators (MLEs) of the regression coefficients under some moment conditions on measurement errors. Under such kinds of moment conditions of measurement errors, the MLEs can be shown to be strongly consistent, asymptotically unbiased and asymptotically normally distributed. Some simulation results of the proposed two-stage procedures are obtained. We also give some numerical studies and real data to verify the theoretical results in different measurement error scenarios.
5

適應性計數值損失函數管制圖之設計 / Design of the Adaptive Loss Function Control Chart for Binomial Data

李宜臻, Lee,I Chen Unknown Date (has links)
This article proposes the algorithm of a new control chart (loss function control chart) based on the Taguchi loss function with an adaptive scheme for binomial data. The loss function control chart is able to monitor cost variation from the process by applying loss function in the design. This new angle economically explores production cost. This research provides designs of the loss function control chart with specified VSI, optimal VSI, VSS and VP, respectively. Numerical analyses show that the specified VSI loss function chart, the optimal VSI loss function chart, the optimal VSS loss function chart and the optimal VP loss function chart outperform the Fp loss function chart significantly and show costs can be controlled systematically.
6

變動樣本大小的無母數平均值管制圖之研究 / Study of nonparametric mean control chart with variable sample sizes

周遊宇, Zhou, Youyu Unknown Date (has links)
自舒華特發明以管制圖監測製程以來,管制圖在工程的應用日趨重要。在特殊工程中,一個高效的管制圖方法尤為重要。基於此項事實,在文獻中各式各樣的管制圖層出不窮且技術日益完善。但傳統管制圖往往受制于常態分佈,因此在無母數管制圖研究方向仍有大量工作值得探討。於是本文在母體分佈未知情況下,推廣Yang (2015)的無母數平均值管制圖方法建立變動樣本指数加权移动平均管制圖,VSS EWMA-np control chart。新的管制圖將變動樣本大小(VSS)和指數加權移動平均(EWMA)方法結合建立一種新的管制圖方法,並用這種新型管制圖監測未知分佈母體的平均值是否發生變動。而為了監測平均數是否發生變化,也為了減少抽樣損失,本文評估管制圖監測效力的指標為管制圖偵測出異常訊息所需抽樣的樣本數期望值(EN)、平均連串長度(ARL)和平均觀測值總數(ANOS)。從本文的比較結果看出新的變動樣本指數加權移動平均管制圖擁有更好的失控偵測力。 / Since Shewhart invention control chart monitor the process, control charts are increasingly important in engineering applications. In special projects, an efficient control chart is especially important. Based on this fact, the various kinds of control charts in the literature are not poor and the technology is improving. However, traditional control charts are often subject to normal distribution, so there is still a lot of work to be discussed in the direction of the study of non-parametric control charts. So in this paper under unknown distribution in the matrix, Yang (2015) established on the basis of the theory of a non-parametric method of control chart - Exponentially Weighted Moving Average Control Chart with Variable Sampling Sizes (VSS EWMA - np control chart). New control chart will change the sample size (VSS) and exponential weighted moving average (EWMA) method to establish a new control chart, and use new control chart for monitoring the mean of unknown distribution matrix is changed. And whether to monitor the average changes in order to reduce the loss of sampling, this paper mainly evaluate control chart for monitoring the effectiveness of the statistics for the expected value of the sample size (EN), the average run length (ARL) and the average number of observations to signal (ANOS). From the comparison shown in this paper, the new control chart has better detection.

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