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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

運用會計資訊預測股票異常報酬─台灣地區股市的實證研究

許嘉琳 Unknown Date (has links)
會計資訊的最高品質即為「決策有用性」,以證券投資而言,投資人是否真能經由會計資訊之分析獲得超額報酬,乃為會計資訊的功能之一。由於國內先前研究對會計資訊是否可得到異常報酬之結論並不一致,且企業之風險因素則從未納入模式加以考量,究竟盈餘及非盈餘資訊是否具有資訊內涵,並可協助投資者衡量企業之風險,進而預測股票異常報酬? 本研究以 Chung and Kim (1994)之模式,採用「風險」因素選取會計變數,並建立預測模型,計算投資績效。經以七十五年至八十四年之國內上市公司為樣本進行全部分析與產業別分析,結果發現: 1. 在全部分析中,買入並持有及賣出之投資決策,皆能得到正的異常報酬,顯示預測模型績效良好;在預測正確率方面,則以賣出決策較佳。 2. 在產業別分析中,食品製造業、紡織業、化學制品業、電力及電子機械業等四產業可得到異常報酬,而銀行業及紙業等二產業則異常報酬為負值,顯示產業別之預測結果相較於全部分析而言,模型適用性並不理想;在預測正確率方面,亦以賣出決策較佳。 3. 整體而言,運用財務比率分析以預測股票異常報酬之結論普遍可獲得支持,亦即台灣股市不具半強式之效率性,投資人可運用財務報表分析預測股票異常報酬,獲取超額收益。
2

波動度預測模型之探討 / The research on forecast models of volatility

吳佳貞, Wu, Chia-Chen Unknown Date (has links)
期望波動度在投資組合的選擇、避險策略、資產管理,以及金融資產的評價上是關鍵性因素,因此,在波動度變化甚巨的金融市場中,找出具有良好預測波動度能力的模型,是絕對必要的。過去從事資產價格行為的相關研究都假設資產的價格過程是隨機的,且呈對數常態分配、變異數固定。然而實證結果一再顯示:變異數是隨時間而變動的(如 Mandelbrot(1963)、 Fama(1965))。為預測波動度(或變異數),Eagle(1982)首先提出了 ARCH 模型,允許預期條件變異數作為過去殘差的函數,因此變異數能隨時間而改變。此後 Bollerslve(1986)提出 GARCH 模型,修正ARCH 模型線性遞減遞延結構,將過去的殘差及變異數同時納入條件變異數方程式中。 Nelson(1991)則提出 EGARCH 模型以改進 GARCH 模型的三大缺點,此模型對具有高度波動性的金融資產提供更成功的另一估計模式。除上列之 ARCH-type 模型外,Hull and White(1987)提出連續型隨機波動模型(continuous time stochastic volatility model),用以評價股價選擇權,此模型不僅將過去的變異數納入條件變異數的方程式中,同時該條件變異數也會因隨機噪音(random noise)而變動。近年來,上述模型均被廣泛運用在模擬金融資產的波動性,均是相當實用的模型。 本文以隨機漫步(random walk)、GARCH(1,1)、EGARCH(1,1)及隨機波動模型(stochastic volatility)進行不同期間下,股價指數與外匯波動度之預測,並以實證結果判斷上述四種模型在預測外匯及股價指數波動度的能力表現。實證結果顯示:隨機波動模型不論在股價指數或外匯、長期或短期的波動度預測上,都是最佳的波動度預測模型,因此建議各大金融機構可採隨機波動模型預測金融資產未來的波動度。 / Volatility forecast is extremely important factor in portfolio chice, hedging strategies, asset management, asset pricing and option pricing. Identifying a good forecast model of volatility is absolutely necessary, especially for the highly volatile Taiwan stock marek. Due to increasing attention to the impact of marke risk on asset returns, academic researchers and practicians have developed ways to control risk and methodologies to forecast return volatility. Past researches on asset price behavior usually assumed that asset price behavior follows random walk, and its probability distribution is a log-normal distribution with a constant variance (or constant volatility). This assumption is in fact in violation of empirical evidence showing that volatility tends to vary over time (e.g., Mandelbrot﹝1963﹞ and Fama﹝1965﹞). To forecast volatility (or variance), Engle(1982) is the first scholar to propose a forecast model, now well-known as ARCH, whose conditional variance is a funtion of past squared returns residuals. Accordingly, the forecast variance(or volatility) varies over time. Bollerslev(1986) proposed a generalized model, called GARCH, which allows the current conditional variance depends not only on past squared residuals, but also on past conditional variances. However, Nelson(1991) has recently proposed a new model, called EGARCH, which attempts to remove the weakness of the GARCH model. The EGARCH model has been shown to be successful to forecast volatility and to describe successful stock price behavior. In addition, Hull and white(1987) employed a continuous-time stochastic volatility model to develop in option pricing model. Their stochastic volatility model not only admits the past variance, but also depends on random noise of volatility. The above-mentioned models have been widely implemented in practice to simulate and to forecast asset return volatility. This thesis investigates whether random walk, GARCH(1,1), EGARCH(1,1) and stochastic volatility model differ in their ability to predict the volatility of stock index and currency returns over short-term and long-term horizons. The results strongly support that the best volatility predictions are generated by the stochasic volatility model. Therefore, it is recommended that financial institutions may adopt stochastic volatility model to predict asset return volatility.
3

明膠產業生產管理:台灣毛豬交易量之分析與預測

高鴻遠 Unknown Date (has links)
充足與質優的原料為明膠產業最重要的關鍵成功因素。但鑒於國內豬皮無法充足供應的前提下,明膠產業只有以國內豬皮原料供應為主國外進口原料為輔的生產策略因應。然而動物性產品受限於動物疫情影響、宗教信仰、保鮮要求、倉儲運輸等限制,加上價格因素等並不容易購買。故在進口採購決策上要如何買的好(品質與價格) 更要買的巧(進廠時程),實需要一套科學性的統計預測工具來協助管理與進口採購決策。 本文探討1999年1月至2006年9月間,台灣毛豬均衡交易量的影響因素,本研究具有下列特色:第一,基於豬隻均衡交易量及交易產地價格每月都在變動,為能擁有更多資訊使模型更具解釋能力及實務上時效性的考量,故本文首次使用「月資料」來驗證影響毛豬月均衡交易量的影響因素。第二,有鑒於季節性變數對台灣毛豬均衡交易量深具影響性,首次加入農曆「季節性變數」,包括農曆新年、清明節、端午節、中元節、中秋節,以及三個季節變數:二月、六月及十二月,做為影響毛豬月均衡交易量的影響因素。第三,本研究以毛豬產地價格(PH)、七公斤仔豬價格(PL)、前一個月毛豬均衡交易量(HOGKNt-1)、前五個月豬隻在養數量(HOGPKt-5)及前三個月每頭毛豬交易的平均重量來配置毛豬均衡交易量模型,所得模型之配置程度高達96.50%。最適配置模型如下: HOGKN =β0 + ( PH *β2) + ( PL *β3 ) + ( HOGKNt-1 *β4 ) + ( HOKGP *β5) + (HOGAW*β6 ) + ( D_NY *β7) + ( D_2 *β8 ) + ( D_6 *β9 ) + ( D_12 *β10 ) +ε 經由實證結果發現一月及十二月的季節變數對毛豬均衡交易量有正向顯著影響;二月及六月的季節性變數具負向顯著影響;而中元節及中秋節的影響並不顯著。 本研究同時發現台灣的毛豬產業已在1999年底結束口蹄疫的影響,已完全由此一疫情影響中回復。但是毛豬產業的產銷結構已因口蹄疫的影響及政府養豬政策的改變所引導,由過去大量外銷日本的產業政策改為目前以供應內銷市場為主的內需型產業。 至於因應自由貿易之需求,加入WTO後自2005年1月1日起全面開放豬肉及其相關製品市場以來,可能由於國人嗜食溫體豬肉之習慣及飲食習慣的改變,至今進口豬肉及內臟的數量在本研究並不具顯著影響。 本研究亦發現國內毛豬之交易價格經研究具有季節性影響與長期走高的趨勢,每年的三、四月份為豬隻交易價格最低的月份,七、八月則為交易行情最高的季節,這可能與台灣三、四月份氣候宜人豬隻成長快速,七、八月份氣候炎熱,豬隻成長減緩存活率下降有關。 此外毛豬交易的平均每頭豬的重量亦具有明顯的季節性影響且有長期走高的趨勢。這一有趣的現象可能係受到養豬政策與科技進步之影響,豬農戶數不斷減少,但單位養殖戶的養殖數不斷升高,豬農們對養豬投入更高的成本與研究,飼料換肉率不斷的提升所致。然而此一現象對養豬相關產業而言,應可進一步探究其源由,並從中找出與善用此一季節性影響利基之所在。
4

建立預測模型之應用框架設計 / An Application framework designed for building forecast models

曹飴珊, Tsao, Yi Shan Unknown Date (has links)
預測技術是一個不斷變動的領域,本研究提出一個高彈性的預測模型應用框架,供使用者開發各種預測系統,且使用者能夠很容易的將新的預測技術增加到系統之中。本研究先分析現有預測模型的建構過程,提出一共通流程。並依此共通流程定義應用框架,該框架可用以產生各種實際的預測系統。此應用框架具備了高度的彈性,除了在流程上可整合OASIS的WS-BPEL流程描述語言外,且可整合各種不同的預測技術所需的運算方法與資料。 / With the rapidly changing forecast technique, this paper introduces a flexible application framework to develop different forecast systems. When you develop a system by this framework, you can add a new forecast technology easily. This paper provides a common process for model building by analysis exiting processes and use this common process to develop application framework. In addition to using an XML-based language, Web Services Business Process Execution Language(WS-BPEL), to describe the details of model building process, this framework can integrates methods and data from different forecast technologies by defining method and data configuration.
5

台灣股票市場投資機率性模型之研究

洪進旺, HONG,JIN-WANG Unknown Date (has links)
台灣股票市場從正式公開交易迄今已有十九年之久,在此期間,參與股票市場的人愈 來愈多,股票市場也歷經無數次的大風大浪,其中大部份的人在風浪中被吞噬,只有 少數的人因有遠見及膽識,不僅能避開被吞噬的惡運,反而因之勇往前進,獲得不少 財富。作者有鑒於此,故提出本研究論文,本論文之內容簡介如下: 第一章:說明研究之目的與動機,以及研究之範圍或限制等。 第二章:說明台灣股票市場之概況。 第三章:說明股票的意義及種類,以及股票價格如何被決定。 第四章:對各種預測模型作一介紹,並加以實證。 第五章:結論及建議。
6

首度上市公司融資選擇行為及預測模式之研究

張邦茹, Chang, Pang-Ru Unknown Date (has links)
本研究以民國75年到88年首度上市、櫃公司為研究樣本,探討它們上市後的首次融資行為。利用羅吉斯迴歸模型驗證抵換理論、資訊不對稱理論、代理理論如何影響樣本公司的對外融資選擇,因為研究樣本的管理者和投資人間的資訊不對稱情形比較嚴重,所以本研究預期樣本公司的首度融資選擇行為應該符合資訊不對稱理論。本研究分別控制產業別、市場景氣、融資年度別及債市活絡程度等因素,驗證5個假說中變數間的關係。但實證結果卻發現,資訊不對稱理論並非樣本公司融資選擇的主要影響因素,而抵換理論是樣本公司融資選擇的主要影響因素。本研究實證的第二部分係依據累積超常報酬率大於零的樣本,建構融資選擇預測模型,預測樣本外的融資選擇行為。 / This paper examined the financing behaviors of IPOs firms in Taiwan from 1986 to 2002 and predicted the financing choices of the sample companies. We want to test Pecking Order theory, trade-off theory, agency theory, other variables – age, firm size and intangible asset ratio, industry variable, and control variables- market variable, financing year variable and bond market. But the result don’t consist the theory. The trade-off theory mainly influenced the financing behavior of the sample. The second empirical model is to construct the prediction model of financing behavior.
7

選舉預測模型之研究-以公元2000年總統大選為例 / The Study of The Election Prediction Model─Take The 2000 Presidential Election for Example

蘇淑枝, Su, Shu-Chih Unknown Date (has links)
中華民國第十任總統選舉結果於民國八十九年三月十八日揭曉,這場眾所矚目的選舉終告落幕,然而對選舉研究工作者而言卻是新的開始。選舉預測居選戰中重要的一環,也是研究選舉的學者關心的問題,更提供了一個驗證選民投票行為理論的絕佳機會,近來國內相關論述已有相當成果。但由於它在投票結束,便有答案,其挑戰程度不言而喻。因此,如何結合理論、方法及事實三者為一體的努力,對選舉預測更是別具意義。 本篇研究之範圍,是以公元2000年總統大選為例,對選舉預測工作做更深層的探討,且檢驗邏輯斯預測模型(Logistic Regression Model)及模糊統計(Fuzzy Statistics)分析在本次總統選舉的預測力,考量本次總統選舉中各項可能影響選情的因素,進一步建構選舉預測模式,然而兩種預測模式的初步預測結果並不佳,經過棄保效應的可能性調整後,預測誤差已大幅降低,其中模糊統計(Fuzzy Statistics)分析預測結果經棄保效應調整後,與實際開票結果相當接近,因此與邏輯斯預測模型相較,模糊統計分析的應用對未表態選民投票意向的預測力較佳。一套完整的選舉預測模型研究,應包含問卷設計、抽樣訪問、資料處理、加權除錯、模型設計與預測評估等整套研究流程,然而在本次總統大選中,由於三強激戰,影響選情因素相當複雜,最後此兩種選舉預測模式皆無法獲致精確的預測結果。因此,我們期待選舉預測模型的建構,能突破主客觀環境的侷限,進一步達到「準」與「穩」的要求。 / With the successful staging of the 2000 presidential elections in Taiwan, scholars have been presented with a new opportunity to test their theories. Electoral predictions are an important field within the study of elections and have been among the most keenly studied questions over the past few years. Unlike many other research topics, there is an absolute standard for election predictions: the election results. Thus, combining theory, methodology, and facts to obtain a meaningful result is no simple task. This thesis attempts to predict the 2000 presidential election using both a logistic regression model and a fuzzy statistics model. After constructing models which includes all kinds of different variables that might influence the electoral outcome, we find that neither the logistic regression model nor the fuzzy statistics model is particularly accurate. However, after accounting for the effects of strategic voting, model error decreases dramatically. In particular, after including provisions for strategic voting, the fuzzy statistics model is improved to the point that its predictions are extremely close to the actual outcome. Thus, we show that the fuzzy statistics model is superior to the logistic regression model in analyzing the vote choices of undecided voters. Research on electoral predictions should include such aspects as questionnaire design, sampling, interviewing, data processing, weighting, data cleaning, model design, and evaluation of the prediction. However, because this election featured a particularly intense three way race, the factors affecting the electoral outcome were both numerous and intertwined in complex ways. Unfortunately, it is impossible to evaluate our electoral predictions of the two models precisely. We hope that in the future, election prediction models will be able to break through these environmental limitations and achieve more accurate and stable predictions.
8

整合文件探勘與類神經網路預測模型之研究 -以財經事件線索預測台灣股市為例

歐智民 Unknown Date (has links)
隨著全球化與資訊科技之進步,大幅加快媒體傳播訊息之速度,使得與股票市場相關之新聞事件,無論在產量、產出頻率上,都較以往增加,進而對股票市場造成影響。現今投資者多已具備傳統的投資概念、觀察總體經濟之趨勢與指標、分析漲跌之圖表用以預測股票收盤價;除此之外,從大量新聞資料中,找出關鍵輔助投資之新聞事件更是需要培養的能力,而此正是投資者較為不熟悉的部分,故希望透過本文加以探討之。   本研究使用2009年自由時報電子報之財經新聞(共5767篇)為資料來源,以文件距離為基礎之kNN技術分群,並採用時間區間之概念,用以增進分群之時效性;而分群之結果,再透過類別詞庫分類為正向、持平及負向新聞事件,與股票市場之量化資料,包括成交量、收盤價及3日收盤價,一併輸入於倒傳遞類神經網路之預測模型。自台灣經濟新報中取得半導體類股之交易資訊,將其分成訓練及測試資料,各包含168個及83個交易日,經由網路之迭代學習過程建立預測模型,並與原預測模型進行比較。   由研究結果中,首先,類別詞庫可透過股票收盤價報酬率及篩選字詞出現頻率的方式建立,使投資者能透藉由分群與分類降低新聞文件的資訊量;其次,於倒傳遞類神經網路預測模型中加入分類後的新聞事件,依統計顯著性檢定,在顯著水準為95%及99%下,皆顯著改善隔日股票收盤價之預測方向正確性與準確率,換言之,於預測模型中加入新聞事件,有助於預測隔日收盤價。最後,本研究並指出一些未來研究方向。
9

運用支持向量機和決策樹預測台指期走勢 / Predicting Taiwan Stock Index Future Trend Using SVM and Decision Tree

吳永樂, Wu, Yong Le Unknown Date (has links)
本研究利用479個全球指標對台指期建立預測模型。該模型可以預測台指期在未來K天的漲跌走勢。我們使用了兩種演算法(支持向量機和決策樹)以及兩種取樣方式(交叉驗證和移動視窗)進行預測。在交叉驗證的建模過程中,決策樹展現了較高的預測力,最高準確度達到了93.4%。在移動視窗的建模過程中,支持向量機表現較好,達到了79.97%的預測准確度。於此同時,不管是哪一種條件設定都表明當我們預測的週期拉長時,預測的效果相對較好。這說明全球市場對台灣市場的影響很大,但是需要一定的市場反應時間。該研究結果對投資人有一定的參考作用。在未來方向裡,可以嘗試使用改進的決策樹演算法,也可以結合回歸預測進行深入研究。 / In this research, we build a stock price direction forecasting model with Taiwan Stock Index Future (TXF). The input data we used is 479 global indices. The classification algorithms we used are SVM and Decision Tree. This model can predict the up and down trend in the next k days. In the model building process, both cross validation and moving window are taking into account. As for the time period, both short term prediction (i.e. 1 day) and long term prediction (i.e. 100 days) are tested for comparison. The results showed that cross validation performs best with 93.4% in precision, and moving window reached 79.97% in precision when we use the last 60 days historical data to predict the up and down trend in the next 20 days. The results imply Taiwan stock market is significantly influenced by the global market in the long run. This finding could be further used by investors and also be studied with regression algorithms as a combination model to enhance its performance.
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預測模型的遺失值處理─選值順序的研究 / Handling Missing Values in Predictive Model - Research of the Order of Data Acquisition

黃秋芸, Huang, Chiu Yun Unknown Date (has links)
商業知識的發展突飛猛進,其中,預測模型在眾多商業智慧中扮演重要的角色,然而,當我們從大量資料萃取隱藏、未知與潛在具有實用性的資訊處理過程時,往往會遇到許多資料品質上的問題而難以著手分析,尤其是遺失值 (Missing value)的問題在資料前置處理階段更是常見的困難。因此,要如何在建立預測模型時有效的處理遺失值是一個很重要的議題。 過去已有許多文獻致力於遺失值處理的議題,其中,Active Feature-Value Acquisition的相關研究更針對訓練資料的選填順序深入探討。Active Feature-Value Acquisition的概念是從具有遺失值的訓練資料中,選擇適當的遺失資料填補,讓預測的模型在最具效率的情況下達到理想的準確率。本研究將延續Active Feature-Value Acquisition的研究主軸,優先考量決策樹上的節點為遺失值選值填補的順序,提出一個新的訓練資料遺失值的選填順序方法─I Sampling,並透過實際的數據進行訓練與測試,同時我們也與過去文獻所提出的方法進行比較,了解不同的填值偵測與順序的選擇對於一個預測模型的分類準確率是否有影響,並了解各個方法的優缺點與在不同情境下的適用性。 本研究所提出的新方法與驗證的結果,將可給予未來從事預測行為的管理或學術工作一些參考與建議,可以依據不同性質的資料採取合宜的選值方式,以節省取值的成本並提高預測模型的分類能力。 / The importance of business intelligence is accelerated developing nowadays. Especially predictive models play a key role in numerous business intelligence tasks. However, while we extract information from unidentified data, there are critical problems of how to handle the missing values, especially in the data pre-processing phase. Therefore, it is important to identify which methods best deal with the missing data when building predictive models. There are several papers dedicated in the research of strategies to deal with the missing values. The topic of Active-Feature Acquisition (aka. AFA) especially worked on the priority order of choosing which feature-value to acquire. The goal of AFA is to reduce the costs of achieving a desired model accuracy by identifying instances for which obtaining complete information is most informative. Followed by the AFA concept, we present an approach- I Sampling, in which feature-values are selected for acquisition based on the attribute on the top node of the current decision tree. Also we compare our approach with other methods in different situations and data missing patterns. Experimental results demonstrate that our approach can induce accurate models using substantially fewer feature-value acquisitions as compared to alternative policies in some situations. The method we proposed can aid the further predictive works in academic and business area. They can therefore choose the right method based on their needs and obtain the informative data in an efficient way.

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