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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.
21

台灣失業率與犯罪關係之初探—不同模型之比較 / Exploration of the relationship between unemployment rate and crimes in Taiwan:A Comparison between Models

魏大耕 Unknown Date (has links)
在過去研究犯罪經濟學的理論文獻上,失業率對各犯罪類型的影響為正向關係,但在實証文獻上的研究發現,卻有愈來愈多的証據支持此二個變數間的負向或無關係。為了解釋上述正向與負向間相反的矛盾關係,本篇論文嘗試利用兩種模型(非參數與非參數模型)與兩種效果(機會效果與動機效果)來解釋此二變數間的關係,此亦是本論文主要貢獻。其中機會效果是用以解釋失業率與犯罪間的負向關係,動機效果則用以解釋正向關係。在非參數模型中,利用失業率為景氣循環的代理變數,發現失業率與竊盜間存在正向關係,此與大多實証研究相符;失業率則和妨害風化與殺人犯罪間呈現負向相關;失業率與傷害罪間則沒有明顯正負關係。研究亦顯示,不同的犯罪類型在不同的參數模型下,統計的顯著性亦有不同,而在不同年齡層(青少年與成年人)的犯罪模型則更與理論模型結論相符。 / According to the theoretical literature on criminal economics, unemployment rate tends to be positively correlated to all types of crimes. However, more and more empirical evidence suggests otherwise. In order to clarify the relationship, this study exploits both nonparametric and parametric models and considers two effects, including opportunity and motivation effects. The presence of the opportunity effect leads to be a negative correlation between unemployment rate and crimes, while the presence of the motivation effect gives a positive correlation. Under nonparametric model where unemployment rate is used as a proxy for business cycles, we only found that there is positive correlation between unemployment rate and robbery, while obscenity and homicide are found to be negatively correlated with unemployment rate. This is in line with most empirical studies. Little correlation evidence is found for unemployment and other types of crimes. Under parametric model, the study indicates that the statistical significance differs in models, and depends on crime variable used. We found more consistent results with theoretic models for the age groups (teenagers and adults).
22

臨床實驗藥量特性之研究 / Characterizing dose response curve in clincal trials

方廷企 Unknown Date (has links)
在製藥工業中,藥量特性之研究常被應用於藥理學、毒物學及臨床試驗中。藥量特性之研究同時在臨床試驗中的第一階段的藥物安全性及第二階段的藥物有效性中扮演著重要的角色。透過藥量特性的研究,使我們對於藥物的開發有著更深一層的認識,並可藉此縮短藥物核准上市的時間。 在多數的情況下,我們對於藥物動力學之參數與藥物劑量間的線性關係,有著特別的興趣。基於這個目的,一些典型的方法即是由一般線性模式發展而成的。然而,這些典型的統計方法常遇到下列的難題而違反其假設:(一)不同藥物劑量間的異質變異性。(二)不滿足常態性的假設。針對這些問題,我們藉由比較不同劑量間的斜率關係的無母數檢定程序來評估其線性關係並刻劃出藥物的反應曲線,文中並藉此方法舉出交叉實驗之實例。 / The problem of characterizing dose response curve for a pharmacokinetic parameter over a specific dose range is considered. In many cases, it is of interest to determine dose linearity (or dose proportionality) between the pharmacokinetic parameters and dose levels. For this purpose, several classical methods based on a general linear model procedure are available. However, two difficulties commonly encountered, namely (i) heterogeneity of the varibility at different dose levels and (ii) violation of the normality assumptions, often make the classical methods not applicable. To account for these problems, we propose a general nonparametric test procedure by comparing the slopes at different dose level to asses dose linearity and to characterize dose response curve. An example concerning the study of dose response of a compound based on a four-way crossover experiment is presented.
23

用拔靴法建構無母數剖面資料監控之信賴帶 / Nonparametric profile monitoring via bootstrap percentile confidence bands

謝至芬 Unknown Date (has links)
近年來剖面資料的監控在統計製程控制中有很大範圍的應用。在這篇論文裡,我們針對監控無母數剖面資料提出一個實務上的操作方法。這個操作方法有下列這些重要的特色:(1)使用一個靈活且有計算效率的無母數模型B-spline來描述反應變數與解釋變數的關係;(2)一般迴歸模型中之殘差結構假設是不需要的;(3)允許剖面資料內之觀測值間具有相關性之結構。最後,我們利用一個無線偵測器的實際資料來評估所提出方法的效率。 / Profile monitoring has received increasingly attention in a wide range of applications in statistical process control (SPC). In this work, we propose a practical proposed guide which has the following important features: (i) a flexible and computationally efficient smoothing technique, called the B-spline, is employed to describe the relationship between the response variable and the explanatory variable(s); (ii) the usual structural assumptions on the residuals are not require; and (iii) the dependence structure for the within-profile observations is appropriately accommodated. Finally, a real data set from a wireless sensor is used to evaluate the efficiency of our proposed method.
24

General Adaptive Penalized Least Squares 模型選取方法之模擬與其他方法之比較 / The Simulation of Model Selection Method for General Adaptive Penalized Least Squares and Comparison with Other Methods

陳柏錞 Unknown Date (has links)
在迴歸分析中,若變數間具有非線性 (nonlinear) 的關係時,B-Spline線性迴歸是以無母數的方式建立模型。B-Spline函數為具有節點(knots)的分段多項式,選取合適節點的位置對B-Spline函數的估計有重要的影響,在希望得到B-Spline較好的估計量的同時,我們也想要只用少數的節點就達成想要的成效,於是Huang (2013) 提出了一種選擇節點的方式APLS (Adaptive penalized least squares),在本文中,我們以此方法進行一些更一般化的設定,並在不同的設定之下,判斷是否有較好的估計效果,且已修正後的方法與基於BIC (Bayesian information criterion)的節點估計方式進行比較,在本文中我們將一般化設定的APLS法稱為GAPLS,並且經由模擬結果我們發現此兩種以B-Spline進行迴歸函數近似的方法其近似效果都很不錯,只是節點的個數略有不同,所以若是對節點選取的個數有嚴格要求要取較少的節點的話,我們建議使用基於BIC的節點估計方式,除此之外GAPLS法也是不錯的選擇。 / In regression analysis, if the relationship between the response variable and the explanatory variables is nonlinear, B-splines can be used to model the nonlinear relationship. Knot selection is crucial in B-spline regression. Huang (2013) propose a method for adaptive estimation, where knots are selected based on penalized least squares. This method is abbreviated as APLS (adaptive penalized least squares) in this thesis. In this thesis, a more general version of APLS is proposed, which is abbreviated as GAPLS (generalized APLS). Simulation studies are carried out to compare the estimation performance between GAPLS and a knot selection method based on BIC (Bayesian information criterion). The simulation results show that both methods perform well and fewer knots are selected using the BIC approach than using GAPLS.
25

等級判別分析法之探討兼論與他種分析法之比較

鄭玉卿, Zheng, Yu-Qing Unknown Date (has links)
第一章為緒論,第一節敘述本文之研究動機與目的,第二節為本文的結構。 第二章為古典判別分析法之概述,共分四節,分別簡介幾種判別分析的基本理論,並 就常態母體導出基判別函數。 第三章為無母數的判別分析法,共分四節,分別敘述四種不同的方法。 第四章為等級判別法特性之探討,是本文重點之一,共分五節,其中並與其他方法加 以比較。 第五章為應用蒙第卡羅方法研究結果,亦是本文探討之重點,從各表格中可看出等級 法、等級轉換法和常態理論判別法之間其精確度各為何,在何種情況下較適合那一種 方法。 第六章為結論,是綜合以上各章所討論的結果,並以個人研討之心得,對這幾種判別 方法作一評述。
26

網路圖書市場與傳統圖書市場定價行為之研究

王亭享 Unknown Date (has links)
摘 要 台灣地區近日網路購物的人數快速成長,因此,消費者對於網路商品的需求大增,是否能從網路商店購買到價廉物美的商品乃為消費者關心的焦點。且根據資策會的調查,書籍是網路購物者的最愛,基於探討網路商店定價行為的國外文獻大抵僅以美國為研究對象,偏重於簡單的統計與迴歸分析,欠缺較深入的統計方法如單因子變異數分析法及集群分析法,加上國內缺乏針對網路商店定價行為從事分析的實證文獻,於是本研究將以書籍為研究對象,蒐集國內傳統書店和網路書店銷售書籍的價格,綜合了迴歸分析、無母數統計、單因子變異數分析及集群分析四大方法從事書店定價行為的分析。本研究先以複迴歸分析探討不同書店之書籍售價的決定因素;再以無母數統計法比較不同購買數量及不同種類的書籍售價;然後,以單因子變異數分析和Turkey、Scheffe兩兩比較法剖析書籍的售價與書店的關聯性;最後,以策略群組分析法探索書店間經營策略的類似性及差異性。 結果顯示,網路書店彼此之間的價格競爭較實體書店之間激烈。書店的書籍銷售價格和資本額、員工數成正向關係,資本額越大、員工數越多則書籍銷售價格越高,書店歷史、商品種類則和書店書籍銷售價格有負向關係,書店歷史越久、商品種類越多,則書籍銷售價格越便宜。再者,比較不同購買數量的書籍售價後發現消費者只要購買兩本書籍以上,網路書店比實體書店便宜,而若消費者只購買一本書籍,在網路書店購買會較吃虧。還有,在工商企管、健康旅遊及文學類三類書籍的價格比較下,書籍售價排序由低到高為文學類、健康旅遊類、工商企管類。接下來,從書籍與書店的關聯性來看,誠品網路書店的書籍銷售價格最高,華文網和搜主義的書籍最便宜。此外,本研究發現,實體書店所開設的網路分店書籍的售價都較實體書店高,而且純網路書店的書籍銷售價格顯著較實體書店的網路分店便宜。 最後,在策略群組分析法中發現19家書店可分為6個群組:節省開銷,專於本業型 (政大書城、上達書局、聯經出版社、今日書局、搜主義網路書店、三民網路書店及誠品網路書店)、圖書館結合百貨公司型 (誠品書店)、大規模經營型 (金石堂書店、新學友書局、博客來網路書店及新絲路網路書店);第四群小百貨公司型 (建宏書局、三民書局、摩爾書店、金石堂網路書店及華文網路書店);第五群致力服務型 (何嘉仁書店);第六群國際級圖書館型 (紀伊國屋書店)。
27

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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