古琴是中國傳統樂器裡最古老的撥絃樂器，具有獨特的演奏技巧與迷人的聲音，其更被聯合國教科文組織列為人類口述和非物質文化遺產代表作。古琴的聲音非常多變，所以需要精細地設計控制電腦合成器。我開發了參數化的激發源與後製濾波器建模法(Source Filter Model)，線性預測編碼(Linear Predictive Coding, LPC)來重新合成具表情特性之古琴音，且此系統能夠盡可能地涵蓋愈多的古琴演奏技巧之組合。
在此篇論文中，簡要地討論了古琴彈奏和其特殊指法標記，以了解其演奏技巧與古琴聲音間的關係。這項工作包含古琴樂譜系統和以激發源與後製濾波器建模法為基礎之合成器，後者採用真實頻譜包絡計算器(True Envelope Estimator)與噪聲水平計算器(Noise Level Estimator)來擬合諧波(Harmonics)與去除諧波後的剩餘部分(Residues)。
此外，我亦將此合成系統實作在當今流行的iOS平台，並建立減字(JianZi)創作界面，讓更多的人了解古琴的指法標記。藉由音高和音長變化與減字譜的創建，使用者可輕易地執行聲音的即興創作。

Guqin as one of Chinese oldest plucked-string instrument has its unique performance techniques and enchanting sounds. It is on the UNESCO Representative List of the Intangible Cultural Heritage of Humanity. The sound of Guqin is various so that carefully designed controls of computer synthesizer are necessary. I developed a parametric source filter model, linear predictive coding (LPC), for re-synthesizing expressive Guqin notes and this system is capable to cover as many as possible combinations of Guqin’s performance techniques.
In this thesis, a brief discussion of Guqin playing and its special tablature notation are made for understanding the relationship between its performance techniques and its sounds. This work includes a Guqin’s musical notation system and a source-filter model based synthesizer, which adopts the true envelope and noise level estimators to fit harmonics and residues of sounds.
In addition, I implement the synthesis system in the popular iOS platform and build up the JianZi creation interface to let more people understand the Guqin tablature notation. It is easy to perform improvisation of the sounds due to time and pitch modification and JianZi Pu creation.

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