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應用Google Analytics於網站流量及 Web2.0社群網站績效表現之關聯性分析 / Utilizing google analytics to study the relationship between operating indexes and the development of Web 2.0 social websites許嘉文, Hsu, Chia Wen Unknown Date (has links)
網際網路的發展讓人們的生活起了變化,Web2.0的概念更是增加了人們對網際網路的依賴性,我們成為網路內容的生產者、我們在社交網站上發表、追縱朋友的動態,以及取得全球世界各地的資訊。在這無限的虛擬空間中隱含的巨大商機,讓各大企業紛紛而至,因而加速了Web2.0社群網站的發展,維持與增加網站流量更是成為社群網站生存的關鍵與重要的績效指標。但社群網站該如何從流量指標之變化來評斷社群網站之績效呢?這是令我們最好奇之處。
藉由Google Analytics提供的流量分析工具,本研究蒐集了台灣四間社群網站1-3年間的流量資訊進行分析,考量蒐集之資訊具時間序列性質特性,本研究首先採用移動視窗法重新進行資料的整理,並據此概念應用在後續的統計分析。此外,本就以指數加權平均法及多元迴歸分析進行流量異常值之偵測,最後,對照各網站重大事件里程碑並與各網站業主進行一對一深訪。故本研究實際上包含質、量化之分析結果。
本篇研究四間個案網站為例,並依網站創造的服務與使用者互動情形流量將其區分為社交互動型與資訊交換型網站,並歸納其在網站流量指標上不同特徵表現及各自可參考之績效評估指標。同時,本研究採用多元迴歸分析做為社群網站績效評估模型,並企圖建構一績效評估分析流程期以做為後續研究者針對網站流量相關研究之參考。 / The development of Internet makes a great influence on human society and the development of Web2.0 enhances human’s dependence on the internet and becomes a channel of social connections. Currently, most contents of the Internet are generated by common users who could retrieve information through the entire network and trace their friends’ actions over the Social Network Sites (SNSs).Owing to the potential business opportunities on the internet, companies try to enter the market causing the prosperities of SNSs. Maintaining or even increasing traffic flows become a critical issue for SNSs to survive in the competitive market. However, how to evaluate the performance of SNSs based on traffic flow indices remains unsolved.This study collected Google Analytics data for 1-3 years from four SNSs’, respectively.Consider the time series charactics, this study applied “Moving Windows“ to organize the data for further statistical analysis.In addition, Exponentially Weighted Moving Average and Multiple Regression Analysis were used to detect the abnormal traffic flows. Finally, these abnormal records were compared with the important events and one-on-one interviewings with the SNSs operators were conducted. The results of this study are based on qualitative and quentitative analysis. This research studiesd four SNSs that were categorized into information-oriented and interaction-oriented services based on their services and users’ interaction. The SNSs at different categories behaved differently following certain characteristics defined previously.A performance evaluation process was developed as a reference for further studies.
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臺北市公共自行車站點需求分析之研究 / A research in the demand of the public bike station in Taipei.張辰尉 Unknown Date (has links)
近年來由於溫室效應加劇以及氣候變遷加劇,因此符合綠色運輸特性的公共自行車系統,成為各國交通部門發展綠運輸政策時的目標之一,同時,大數據分析亦是目前受到高度關注的熱門議題。而本研究首先使用臺北市微笑單車租借大數據探討在不同時間點下民眾日常使用微笑單車之旅運行為,分析不同站點間的旅次特性。再運用社群網絡分析,以站點之間旅次連結多寡作為權重,探討站點間之緊密程度,以及不同時間點下微笑單車租借量之熱點分布情形,並將其視覺化呈現。
後續透過文獻分析,擷取影響公共自行車使用量之因素後,本研究嘗試運用一般線性迴歸模型與地理加權迴歸進行模型建立,並探討各影響因素對於旅運需求之影響情形。實證結果顯示,地理加權迴歸模型可以解決一般線性迴歸所產生空間自相關問題,使得模型解釋能力獲得改善。本研究並使用地理加權迴歸進行使用需求分析以及預測,對未來公共自行車營運以及站點擴張提出結論以及建議,期能提升公共自行車系統之使用量。 / Due to the climate change and aggravation of the greenhouse effect in recent years, the public bicycle system with the feature of low-carbon emission has raised more and more attention internationally, and has become one of the targets in developing green transportation policies of transportation departments of governments around the world. Meanwhile Big Data analysis issues, on the other hand, are currently a sought-after topic which has caused great concern as well. In this study, we utilize the rental data of the YouBike system in Taipei to discuss the public usage of YouBike tour at different periods. With the use of social network analysis, we discuss the relationships between different bicycle stops based on applying the number of travels between different sites as the weight. Eventually, the hotspot analysis will be carried out by operating the GIS system. In this way, we are able to discuss the hotspot distribution of YouBike rentals in different time and then visualize the result.
After that this study pick up the variables which will effect the YouBike usage by reference review. This research try to built models by utilizing the Least Squares Method and Geographically Weighted Regression. Then we will have a discussion with the result of the two models. The result shows that Geographically Weighted Regression can resolve the spatial autocorrelation problem which happened in the Least Squares Method and to gain a better result. With the analysis and prediction of public bicycle system from Geographically Weighted Regression, we hope to raise the usage of public bicycle system by concluding as well as making recommendations for the future operation of public bicycle and the expansion of bicycle stops.
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複迴歸係數排列檢定方法探討 / Methods for testing significance of partial regression coefficients in regression model闕靖元, Chueh, Ching Yuan Unknown Date (has links)
在傳統的迴歸模型架構下,統計推論的進行需要假設誤差項之間相互獨立,且來自於常態分配。當理論模型假設條件無法達成的時候,排列檢定(permutation tests)這種無母數的統計方法通常會是可行的替代方法。
在以往的文獻中,應用於複迴歸模型(multiple regression)之係數排列檢定方法主要以樞紐統計量(pivotal quantity)作為檢定統計量,進而探討不同排列檢定方式的差異。本文除了採用t統計量這一個樞紐統計量作為檢定統計量的排列檢定方式外,亦納入以非樞紐統計量的迴歸係數估計量b22所建構而成的排列檢定方式,藉由蒙地卡羅模擬方法,比較以此兩類檢定方式之型一誤差(type I error)機率以及檢定力(power),並觀察其可行性以及適用時機。模擬結果顯示,在解釋變數間不相關且誤差分配較不偏斜的情形下,Freedman and Lane (1983)、Levin and Robbins (1983)、Kennedy (1995)之排列方法在樣本數大時適用b2統計量,且其檢定力較使用t2統計量高,但差異程度不大;若解釋變數間呈現高度相關,則不論誤差的偏斜狀態,Freedman and Lane (1983)、Kennedy (1995) 之排列方法於樣本數大時適用b2統計量,其檢定力結果也較使用t2統計量高,而且兩者的差異程度比起解釋變數間不相關時更加明顯。整體而言,使用t2統計量適用的場合較廣;相反的,使用b2的模擬結果則常需視樣本數大小以及解釋變數間相關性而定。 / In traditional linear models, error term are usually assumed to be independently, identically, normally distributed with mean zero and a constant variance. When the assumptions cannot meet, permutation tests can be an alternative method.
Several permutation tests have been proposed to test the significance of a partial regression coefficient in a multiple regression model. t=b⁄(se(b)), an asymptotically pivotal quantity, is usually preferred and suggested as the test statistic. In this study, we take not only t statistics, but also the estimates of the partial regression coefficient as our test statistics. Their performance are compared in terms of the probability of committing a type I error and the power through the use of Monte Carlo simulation method. Situations where estimates of the partial regression coefficients may outperform t statistics are discussed.
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半導體晶圓廠投資策略與預測莊坤榮 Unknown Date (has links)
在全球持續電子化的過程中,台灣一路扮演著落實有效製造與實現設計的推手,無論從主機板、被動元件、面板、晶片設計、晶圓製造以及封裝甚至高精密組裝無所不包,在如此資本密集產業,如何操作才能達到供需平衡,為整體產業經濟創造出良性的競爭平台,避免惡性競爭,就成了不可輕忽的課題。
本文以晶圓產業為探討對象。全球產能平均利用率多年來總維持於中檔 (88%), 且平均銷售單價只能緩降而無強勢反彈,近年企業無不減少資本支出來度過低潮,整合元件製造廠(IDM)相繼喊出工廠資產輕化(fab-lite)的營運策略,這時我們的命題即是:要不要繼續投資?如何調整價值鏈?
本研究中,我們會先檢視目前市場對半導體成長預測的準確度,再經由產業價值活動代表性指標回歸分析法對相關參數做一整合之解析,對晶圓需求量與銷售價建立配適之模型,找出先行指標來達到預測,並定義上下限以供快速比對分析,最後再根據分析結果提出可能之產業趨勢議題。 / This thesis analyzes the semiconductor industry growth worldwide. The leading index via regressions has been established to achieve a reliable forecast on worldwide ASP, wafer demand and revenue.
In the long run, we expect the semiconductor demand will continue to grow at CAGR 8% (compound annual growth rate) and display less extreme cycles than past decade. However, revenue’s CAGR might be diluted to around 5%, lower than demand’s growth. Moreover, it might go down to zero-growth for some times since the ASP still slightly trend down before emerging market demand really expanded.
Continuous outsourcing is one possible solution for IDM to be fab-lite, since fab’s fix charge is billion- base that needs high utilization to maintain break-even operation. But what is the solution for foundry side to avoid ASP erosion all the way down? Our analysis identifies a need for executive managers to well predict the demand on capital expenditure when making decision.
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變數轉換之離群值偵測 / Detection of Outliers with Data Transformation吳秉勳, David Wu Unknown Date (has links)
在迴歸分析中,當資料中存在很多離群值時,偵測的工作變得非常不容易。 在此狀況下,我們無法使用傳統的殘差分析正確地偵測出其是否存在,此現象稱為遮蔽效應(The Masking Effect)。 而為了避免此效應的發生,我們利用最小中位數穩健迴歸估計值(Least Median Squares Estimator)正確地找出這些群集離群值,此估計值擁有最大即50﹪的容離值 (Breakdown point)。 在這篇論文中,用來求出最小中位數穩健迴歸估計值的演算法稱為步進搜尋演算法 (the Forward Search Algorithm)。 結果顯示,我們可以利用此演算法得到的穩健迴歸估計值,很快並有效率的找出資料中的群集離群值;另外,更進一步的結果顯示,我們只需從資料中隨機選取一百次子集,並進行步進搜尋,即可得到概似的穩健迴歸估計值並正確的找出那些群集離群值。 最後,我們利用鐘乳石圖(Stalactite Plot)列出所有被偵測到的離群值。
在多變量資料中,我們若使用Mahalanobis距離也會遭遇到同樣的屏蔽效應。 而此一問題,隨著另一高度穩健估計值的採用,亦可迎刃而解。 此估計值稱為最小體積橢圓體估計值 (Minimum Volume Ellipsoid),其亦擁有最大即50﹪的容離值。 在此,我們也利用步進搜尋法求出此估計值,並利用鐘乳石圖列出所有被偵測到的離群值。
這篇論文的第二部分則利用變數轉換的技巧將迴歸資料中的殘差項常態化並且加強其等變異的特性以利後續的資料分析。 在步進搜尋進行的過程中,我們觀察分數統計量(Score Statistic)和其他相關診斷統計量的變化。 結果顯示,這些統計量一起提供了有關轉換參數選取豐富的資訊,並且我們亦可從步進搜尋進行的過程中觀察出某些離群值對參數選取的影響。 / Detecting regression outliers is not trivial when there are many of them. The methods of using classical diagnostic plots sometimes fail to detect them. This phenomenon is known as the masking effect. To avoid this, we propose to find out those multiple outliers by using a highly robust regression estimator called the least median squares (LMS) estimator which has maximal breakdown point. The algorithm in search of the LMS estimator is called the forward search algorithm. The estimator found by the forward search is shown to lead to the rapid detection of multiple outliers. Furthermore, the result reveals that 100 repeats of a simple forward search from a random starting subset are shown to provide sufficiently robust parameter estimators to reveal multiple outliers. Finally, those detected outliers are exhibited by the stalactite plot that shows greatly stable pattern of them.
Referring to multivariate data, the Mahalanobis distance also suffers from the masking effect that can be remedied by using a highly robust estimator called the minimum volume ellipsoid (MVE) estimator. It can also be found by using the forward search algorithm and it also has maximal breakdown point. The detected outliers are then displayed in the stalactite plot.
The second part of this dissertation is the transformation of regression data so that the approximate normality and the homogeneity of the residuals can be achieved. During the process of the forward search, we monitor the quantity of interest called score statistic and some other diagnostic plots. They jointly provide a wealth of information about transformation along with the effect of individual observation on this statistic.
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排列檢定法應用於空間資料之比較 / Permutation test on spatial comparison王信忠, Wang, Hsin-Chung Unknown Date (has links)
本論文主要是探討在二維度空間上二母體分佈是否一致。我們利用排列
(permutation)檢定方法來做比較, 並藉由費雪(Fisher)正確檢定方法的想法而提出重標記 (relabel)排列檢定方法或稱為費雪排列檢定法。
我們透過可交換性的特質證明它是正確 (exact) 的並且比 Syrjala (1996)所建議的排列檢定方法有更高的檢定力 (power)。
本論文另提出二個空間模型: spatial multinomial-relative-log-normal 模型 與 spatial Poisson-relative-log-normal 模型
來配適一般在漁業中常有的右斜長尾次數分佈並包含很多0 的空間資料。另外一般物種可能因天性或自然環境因素像食物、溫度等影響而有群聚行為發生, 這二個模型亦可描述出空間資料的群聚現象以做適當的推論。 / This thesis proposes the relabel (Fisher's) permutation test inspired by Fisher's exact test to compare between distributions of two (fishery) data sets locating on a two-dimensional lattice. We show that the permutation test given by Syrjala (1996} is not exact, but our relabel permutation test is exact and, additionally, more powerful.
This thesis also studies two spatial models: the spatial multinomial-relative-log-normal model and the spatial
Poisson-relative-log-normal model. Both models not only exhibit characteristics of skewness with a long right-hand tail and of high proportion of zero catches which usually appear in fishery data, but also have the ability to describe various types of aggregative behaviors.
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不動產投資信託與直接不動產投資關係之探討 / The relationship between real estate investment trusts and direct real estate investment邱逸芬, Chiu, Yi Fen Unknown Date (has links)
台灣不動產投資信託(T-REITs)自2005年發行至今已逾六年,然其市場表現仍不如發行之初所預期。過去國內已有許多研究針對T-REITs市場發展進行探討,然而目前就T-REITs與直接不動產投資市場價格表現間之相關研究尚付之闕如。有鑑於此,本研究藉由共整合與Granger因果關係檢定,檢視REITs與直接不動產市場間之關聯性,了解台灣與美國之REITs市場表現差異及其影響因素,進而作為改進T-REITs運作機制或架構之參考依據。
實證結果發現,美國之REITs與直接不動產市場之間存在共整合關係。此結果表示,長期而言,這兩者可能具有相似之風險分散效益。此外,透過Granger因果關係檢定發現REITs領先於直接不動產,乃因前者市場較具效率。另一方面,台灣之REITs與直接不動產市場之間則不具有共整合以及領先或落後關係,然直接不動產當期價格仍會受到本身與REITs之前期價格影響。
本研究進一步分析台、美兩國實證結果之差異原因如下:資料的樣本期間、REITs市場規模、存在於T-REITs市場之集中性風險以及潛在的代理問題。其中,針對T-REITs潛在代理問題,本研究藉由分析股票與T-REIT報酬率之波動性,發現T-REIT之不動產管理機構若與母集團相關者,則其市場表現較差。因此,我們得出T-REITs市場發展主要是受限於代理問題之結論。本研究成果不僅有助於改善T-REITs市場效率,亦可提供學術與實務之參考。 / The mechanism of Real Estate Investment Trusts in Taiwan (or T-REITs) was launched in 2005, however, T-REITs market did not perform as expected. What caused the limited development of T-REITs market? Current literature on the performance between T-REITs and direct real estate investment is limited. Through the cointegration and Granger causality tests, the purpose of this study is hence to explore the short-term and long-term dynamics between REITs and direct real estate markets in the U.S. and Taiwan, respectively.
This study presents evidence of the cointegration relationship between REITs and direct real estate in the U.S. It implies that the diversification properties of these two assets are likely to be similar over the long horizon. According to the Granger causality test, REITs leads direct real estate due to the market information efficiency. These findings are consistent with those of previous studies. On the other hand, we find no cointegration and lead-lag relation between T-REITs and commercial real estate. Moreover, the current commercial transaction price is affected by both its and T-REIT previous price.
By comparing the difference between the results of these two countries, there are several possible explanations for the different results between the U.S. and Taiwan, including difference in sample period, market capitalization, concentrated risk, and most importantly, the potential agency problem existing in T-REITs market. Finally, the underperformance of parent-related management T-REIT is verified through the volatilities of stock and T-REIT returns. Therefore, we conclude that the limited development of T-REITs is caused by the agency problem in REITs market. Results of this study may provide T-REITs market for improving its efficiency, as well as for the reference for both academics and real practices.
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