A Study on the Technology of e-Learning

[[abstract]]近年來，網際網路使用人口成長快速，不只企業及學術單位之需求日增，連一般家庭對網路的需求也急遽增加。在網際網路眾多的應用中，e-Learning改變了傳統學習的模式，使得網路快速方便、零距離、提高教育品質、降低教育成本的特性發揮得淋漓盡致。 e-Learning教學方式分為同步網路教學與非同步網路教學兩種，非同步網路教學是將授課教材以網頁的方式展現，至於同步網路教學，有以ISDN或其他寬頻網路配合硬體設備來進行，但此種做法成本較高且受限於必須在有硬體設備的空間中才能實施；另有以NetMeeting或RealPlayer等視訊會議軟體，搭配網頁實施教學活動，此方式若同時有多人上線，其中音/視訊部分將受限於目前網際網路的頻寬，而無法正常運作。 本論文以建構一個兼具同步網路教學與非同步網路教學的e-Learing學習系統為目標，先以ASP設計一套課程管理系統來管理帳號與成績，以PowerPoint製作投影片，再以「另存成Web畫面」的方式產生網頁，將NetMeeting的部分功能寫成ActiveX，再運用JavaScript將這些ActiveX嵌入到網頁中，免除學員必須熟悉NetMeeting使用者介面的困擾。 再者，我們用 C語言模擬LPC音碼器，以低位元率為目標，探討在降低階數情況下對合成語音品質的影響程度。實驗結果顯示，當SNR值相近，中文語音之MOS平均值高於英文語音之MOS平均值，所以在低位元率編碼相同情況下，中文語音合成品質應是優於英文語音。[[abstract]]In recent years, the number of the Internet users grows rapidly. The need of the Internet is increasing daily not only in businesses and academic organizations, but also in families. As for the various applications of the Internet, e-Learning changes the traditional learning model and elaborates the best characteristics of the Internet, such as speed, convenience, the ignorance of distance, the enhancement of teaching quality and the reduced cost. There are two teaching methods of e-Learning. One is synchronous online teaching; the other is non-synchronous online teaching. In non-synchronous online teaching, the teaching material is demonstrated by web pages, while the synchronous one has to be adopted with ISDN and other wideband network coordinated with hardware devices, which, however, costs more and is constrained by the equipment. Besides, in the teaching activities conducted via web pages associated with the video conferencing software, like Net Meeting or Real Player, the audio and video part will be restricted by the bandwidth of the network while many people are online simultaneously, and then . function defectively. The objective of this thesis is to establish an e-Learning system based on both synchronous online teaching and non-synchronous online teaching. First, I design a course management system by ASP to manage the accounts and the grades. Secondly, I make the task panes by PowerPoint, and then produce the webpage by the function, “save as webpage”. Thirdly, I transfer parts of the functions of NetMeeting into ActiveX and use JavaScript to have these ActiveX embed into the webpage. Such will prevent students from the trouble of being required to be familiar with the User Interface of NetMeeting. Furthermore, in order to achieve the low bit rate, we use C language to simulate the LPC Vocoder and probe into the influence on the quality of the synthetic speech sounds under the circumstance of reducing the order. The result shows that the average MOS of Chinese speech sounds is higher that that of English speech sounds when the SNR is approximate. Therefore, under the same condition of the low bit-rate coding, the quality of Chinese synthetic speech sounds is superior to that of English ones