遠距教育一直是一個重要而熱門的研究議題，尤其是應用在多媒體電腦和其通訊方面。自從教育教學的活動實現於電腦網際網路的空間之後，大家已深深地體認出，如何在網路中控制學生的行為和增大網路通訊的頻寬，則是一個極富挑戰而前瞻性的問題。我們呈現出一個先進的Petri Net模型，分析多個參加者在網路虛擬環境中的工作流程，提出之方法不僅能顯著的幫助開發者了解客戶機伺服器在虛擬環境之間的互動關係，而且容易建構一個共享的虛擬世界。我們提出一種基於鷹架理論的系統和發展出一種敘述性的規範語言，由教師使用來設計出一種基於Petri Net理論的規則狀態機器，讓學生在網路中的行為，被一個為教師而量身定做的智慧型之控制系統所監督，而這一般化工具界面的智慧型的控制系統，則是架構在虛擬實境和即時通訊技術之下。在虛擬網路世界中，學生和教師有其個別的化身，而此化身在網路世界中的行為是由像電動遊戲般模式的瀏覽器所控制。當學生有不當的行為而觸犯了虛擬校園規則時，其行為馬上會被發現、糾正，甚至於馬上限制其在虛擬校園中的行動。因多位用戶在網絡中互動所產生的問題和利用Petri Net模型解決問題，在這裡會詳細說明。這篇論文能夠當作一個基本的研究架構和學習及理解遠距學習的特性，並且作為探索它最佳的教育應用工具。

Distance education has been an important research issue of multimedia computing and communication. Since the instructional activities are implemented on cyberspace, how to control behaviors of students and to increase the degree of communication awareness has been a challenging issue. We present an advanced Petri Net model to analyze the workflow of a web-based multiple participants virtual environment. The presented approach not only can conspicuously help the developer to comprehend the interaction relationship between the client-server virtual environments but also to easily construct a shared virtual world. We proposed a system based on the scaffolding theory, and developed a declarative specification language for instructors to use in designing a rule-based state machine, based on Petri Net theory. Behaviors of students are supervised by an intelligent control system, which is programmed by the instructor under our generic interface. The interface is built based on virtual reality and real-time communication technologies. Students and instructors have their individual avatars that are controlled by a video game like navigation. Those behaviors that violate virtual campus regulations are detected and interceptive actions are performed. Problems of providing the multi-user interaction on the Web and the solutions proposed by the Petri Net model are fully elaborated here. This paper can be used as a basic/fundamental research framework and tools to study and understand the characteristics of e-learning and to explore its optimal education application.

Contents…………………………I
List of Figures………………III
List of Tables…………………IV
Chapter 1 Introduction………1
1.1 Motivation and Objectives………1
1.2 An Integrated e-Learning platform based on SCORM and SOAP……………4
1.3 Organization of this Dissertation…………10
Chapter 2 The Scaffolding Theory for Distance Learning……11
2.1 The Relationship between multiple participants…………11
2.2 The Social Constructivism and the Scaffolding Theory…15
Chapter 3 Activity Supervision and Behavior Understanding Model....23
3.1 Petri Net Model for Activity Supervision and Behavior Understanding………27
3.2 The Establishment of Activity Supervision Model………34
3.2.1 The Registration Stage……………………………………35
3.2.2 The Curriculum Stage………………………38
3.2.3 The Authoring Stage…………………………………40
3.2.4 The Examination Stage………………………42
3.2.5 The Assessment Stage…………………45
Chapter 4 Architecture of the Virtual University System………48                         
4.1 The Diagram of the Virtual University System………………………………48
4.2 The Assessment Strategies in Distance Learning……………………………50
Chapter 5 The Construction of 3D Campus Scenes and a Generic Layout of User Interface …………………56
5.1 A Generic Layout of User Interface Tools for Scenes………………56
5.2 The Scenes of 3D Campus…………………………60
5.2.1 The Virtual Open Plaza………………………60
5.2.2 The Virtual Library…………………………61
5.2.3 The Virtual Faculty Office……………………………63
5.2.4 The Virtual Discussion Room………………64
5.2.5 The Virtual Classroom………………………66
Chapter 6 A Declarative Specification Language for Learning 
Behavior Supervision………………………………………68
6.1 The Definition and Application of the Declarative Specification Language……...69
6.2 Graphical User Interface of a Declarative Specification Program………………81
6.3 Analysis of Collaborative Learning Behavior……………………83
Chapter 7 Conclusions and Further Researches……………85
7.1 Conclusions…………………………………………………85
7.2 Further Researches………………………………………………………86
Bibliography……………………………………………………87
List of Figures
Figure 1: The impact of network on media used in distance learning…………………2
Figure 2: An Integrated e-Learning platform based on SCORM and SOAP……………6
Figure 3: A diagram of six interactive dyads possible………………………………12
Figure 4: The Scaffolding-by-Design Model…………………………………………20
Figure 5: The Petri Net model for Registration Stage……… …………………36
Figure 6: The Petri Net model for Curriculum Stage………………………………39
Figure 7: The Petri Net model for Authoring Stag……………………………………41
Figure 8: The Petri Net model for Examination Stage………………………………43
Figure 9: The Petri Net model for Assessment Stage………………………………46
Figure 10: A diagram of the Virtual University System including Teacher Creating, Host 
Offering, and Learner Accessing phases……………………………………49
Figure 11: A diagram of extensive database for tracking all aspect of learning…………52
Figure 12: A common cycle of testing process (developing, conducting and reporting)....54
Figure 13: A generic layout design of user interface……………………………………59
Figure 14: Preliminary Design of the Open Plaza……………………………………61
Figure 15: Preliminary Design of the Library………………62
Figure 16: Preliminary Design of the Faculty Office……………………………64
Figure 17: Preliminary Design of the Discussion Room………65
Figure 18: Preliminary Design of the Classroom……………67
Figure 19: The Graphical User Interface of the Declarative Specification………………83
List of Tables
Table 1: Distinguishes between Traditional University and Virtual University…………3

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