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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

應用連串技術分析於投資決策:以NASDAQ指數為例 / Applying run technical analysis in investment: experimen of NASDAQ index

楊喻翔, Yang, Yu-Hsiang Unknown Date (has links)
本文主旨是利用連串理論(RUNS)的觀念引入現行的簡單移動平均法則的技術分析中,實證發現在以逐日作投資決策而進行的交易中,引入連串的簡單移動平圴預測來作交易決策的績效可以跟買入後持有的績效相同,而根據不引用連串觀念的簡單移動平均所作旳預測來進行交易的績效則明顯不如買入後持有的績效, 這樣的結果說明了有連串觀念的簡單平均含有某些獲利訊息。另以逐波作投資決策進行的交易中,研究結果顯示以類神經網路預測而進行交易決策的績效比以多元迴歸預測的為佳,但二者皆可獲得正的超額報酬。 就理論而言,本文延續Gencay and Stengos(1998)所作的簡單移動平均研究,關於簡單移動平均等此類的技術分析探討自Alexander(1964)用濾嘴法則開始研究後,就陸陸續續在財務領域中被探討,例如Brock et al.(1992)發現這些技術分析法則在高報酬及低波動度(returns are high and volatility is low)時可以進行作多獲利(to be in the market or long the index)。本文首先嘗試引用連串移動平均法則來進行預測,文中的3個連串移動平均(the moving average of 3 runs)實是在計量驗證下求得的。以連串移動平均預測而進行交易操作是一種順勢而為的交易方法,其研究實證所獲得超額報酬是正的。
2

無母數指數加權移動平均管制圖伴隨變動管制界限 / A Nonparametric EWMA-Type Signed-Rank Control Chart with Time-Varying Control Limits

鄭舜壕 Unknown Date (has links)
根據Steiner (1999) 提出指數加權移動平均 (EWMA) 管制圖之管制界限應伴隨時間變動,相較於傳統以漸近管制界限建構的 X-bar EWMA 管制圖,具備類似於快速起始反應之功能。然而,無母數EWMA 管制圖相關文獻中,大多採用漸近管制界限,甚少提及變動管制界限對於製程初期偵測能力之影響,因此本研究依據Wilcoxon 符號排序統計量為基礎,建構無母數EWMA 管制圖,並定義變動管制界限之形式,進而探討在製程初期的監控效果。假設製程為常態、均勻或雙指數分配下,使用非齊一性馬可夫鏈及蒙地卡羅模擬,求得製程穩定或失控狀態下的平均連串長度。模擬結果顯示,當加權常數越小,若採用變動管制界限能有效提升對於製程初期異常之偵測能力,且在厚尾分配下(例如:雙指數分配) 效果更為明顯。 / According to Steiner (1999), the control limits of exponentially weighted moving average (EWMA) control charts should vary with time, so that the charts would have properties similar to the fast initial response (FIR) feature, when compared with asymptotic X-bar EWMA charts. However, previous analyses of nonparametric EWMA control charts consider only asymptotic control limits and are not sensitive to the shifts in a process at early stages. In this thesis, a nonparametric control chart with time-varying control limits is constructed based on EWMA control chart built upon the Wilcoxon signed-rank statistics. When the underlying distribution is normal, uniform, or double exponential, the average run lengths in both in-control and out-of-control conditions are approximated using non-homogenous Markov chain and based on Monte Carlo simulations. Simulation results show that EWMA charts with varying control limits are more efficient to detect early process shifts when weighting constants are small, and the underlying distributions are heavy-tailed distribution (such as double exponential distribution).
3

量測誤差對偵測小幅偏移量管制圖之效應

蔡麗美, Tsai, Li-Mei Unknown Date (has links)
對於任何一種產品不論其設計如何完善,製造過程如何完備,機器如何精密,操作技術如何純熟,所製造出來的產品一定會有所差異。造成產品差異性的原因有很多,其中因素之一為:量測產品的特性所使用的量測設備,可能因為量測的不精確進而存在量測誤差,以至於測量產品特性值不正確。以往建立管制圖之數學模式中,大多不考慮測量誤差的存在,因為一般認為量測誤發生次數或頻率太少,故在模式中忽略了量測誤差的重要性。目前沒有相關文獻探討量測誤差對偵測小偏移量管制圖之效應,因此本研究考慮在製程含有量測誤差的情形下建立EWMA管制圖和 區域管制圖,且分別以Crowder(1987a,b)提出的數值方法和Davis, Homer and Woodall(1990)提出的馬可夫鏈(Markov Chain)的方法計算EWMA管制圖和 區域管制圖之平均連串長度,分析探討量測誤差分別對EWMA管制圖和 區域管制圖的設計參數及偵測能力之影響,最後比較EWMA管制圖和 區域管制圖的偵測力差異。
4

少量連串下最適設計參數值之決定 / The Decision of the Best Fitted Design Parameters on Small Runs

嚴珮文, Yen, Pay Wen Unknown Date (has links)
管制圖之經濟模型首由Duncan(1956)提出,自此之後陸續有學者致力研究經濟管制圖,包括X-bar管制圖、S管制圖等。但R管制圖之經濟設計目前尚無人提出。而在實務上,部份產業可能由於產品過於昂貴,或者產品的製造時間所需甚長,而使得品檢時所抽取的樣本數無法達到25個,這時若採用傳統的管制圖來分析製程,將無法顯示製程真正的狀態。因此本研究首先探討少量連串下X-bar和R管制圖之製作原理,並計算及整理出較完整的少量連串下X-bar和R的管制係數表。接著假設非機遇因素只影響製程運用Banerjee和Rahim(1987)的更新理論方法,建立少量連串情形下的R經濟管制圖。再利用最佳化方法,即可求得最適設計參數值。於是,少量連串情形下的R經濟管制圖得以建立。最後,我們將舉一個例子來說明如何獲得最適設計參數值、決定關鍵參數,以及少量連串情形下R經濟管制圖之建立與應用。
5

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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