2005 IEEE International Professional Communication Conference Proceedings

0-7803-9028-8/05/$20.00 © 2005 IEEE.

Virtual Classroom Implementation on the Web

Sen CakirDokuz Eylül University sen@cs.deu.edu.tr

Havva Haciogullari Basak Dokuz Eylül Universit havvahaciogullari@yahoo.com

Abstract

The World Wide Web (WWW) provides new opportunities for distance education over the Internet. The Web, when combined with other network tools, can be used to create a virtual classroom to bring together a community of learners for interactive education. In this paper we discuss moving some of educational instructions of the Institute of Science Dokuz Eylül University to the WWW. This objective is achieved by investigating the use of emerging network technologies for training full-time students and part-time students. This research focuses on developing a virtual classroom on the Web, using recent development tools.

Keywords: Distance Education, Virtual Classroom, Virtual University

1. Introduction

Distance learning is developing rapidly. Numerous web-based education systems have been created around the world, for example, the Virtual-U [1] and Web-CT [2]. In order to cover all the phases of the learning process, these systems are usually comprised of such fundamental components as synchronous and asynchronous teaching systems; course-content delivery tools; polling and quiz modules; virtual workspaces for sharing resources; white boards; grade reporting systems; assignment submission components; and many more. These products enable large groups of dispersed individuals to interact, collaborate, study, and be assessed over the Internet.

In this paper, we explore the creation of a virtual classroom for Dokuz Eylül University (DEU) on

the World Wide Web (WWW). The main aim of our project is to create a virtual classroom for DEU students and staff, which will be a user-friendly and efficient collaboration and teaching environment. This online collaboration environment includes communication, productivity, student involvement, administration, and course delivery tools. We present a framework that focuses on online collaboration tool design and implementation.

2. Overview of System Architecture

Video communication has an important place among distance learning technologies. It is used in a range of interactions from casual and business communication to telemedicine and education. The advantages of video communication are the richness of visual cues and social contact that are missing in chat and whiteboard applications.

2.1 Activity During the class all the data, including the video, audio, handwritten material and screen operation, are transferred synchronously to each student’s desktop. At the same time, all interactions are recorded, and those that are public material are published on the web. Thus those students who are not available at the class time can view on the web site the same content as those who attended the classes.

2.2 Bandwidth Management Recent advancements in network bandwidth, compression technologies and computer performance have led to the routine use of video-on-demand. It appears that viewers’ access patterns differ markedly from live attendance or when watching a synchronous transmission. On-demand video allows users to watch the videos where and when they like, jump from one

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segment to another, forwarding and reviewing and at the same time being able to access other relevant materials like slides and documents. These patterns of usage demand that digitalized videos are structured in a certain way, with a table of contents available together with possibilities for quick movement between presentation segments. An example of a system for internal technical education to corporate employees that provides these facilities is Microsoft Technical Education (MSTE).

There are three main types of videoconferencing tools. The first is room-based, where several people share a video site. An example is the MAGIC design by Okada et al. [3]. This system provides a simulation of a multi-way round table meeting with life-size images of participants together, which enables eye contact. Second, desktop videoconferencing combines different collaboration technologies, for example, the Distributed Collaborative Video Viewing System (DCVV) [4]. This system allows students in different locations to watch a lecture on a video and communicate with each other by telephone, video or chat. They can stop and start the video when needed. The system was implemented by combining Windows Media Player and Microsoft NetMeeting. Third, media spaces alter physical space and augment it by using electronic media (primarily video). A media space was created in the Xerox Palo Alto Research Centre, connecting Palo Alto, California and Portland. [5]. Both individual offices and public areas like the break room were connected, allowing workers to locate colleagues and start both individual videophone conversations and group discussion.

There are four major technical requirements to use video conferencing. The first consists of equipment like cameras and microphones. In our system Web cameras are used widely. These cameras are cheap and easy to deploy in our system. Microphones and headphones can easily be obtained. The second requirement is for cameras aimed towards the speaker to capture the speaker’s gaze. We use a Macromedia Incorporates [7] product, Macromedia Communication Server release 1.5, to capture and publish the users’ video and voice to all parties. The third requirement is a codex for compressing and decompressing video frames. Macromedia has its own player, called Flash, to play the online video motions. The frames of these motions are

controlled by Macromedia Communication Server software. The fourth requirement is for Integrated Services Digital Network (ISDN), Virtual Private Network (VPN), and Local Area Network (LAN) or modem connection. Expected clients will connect to the system from their homes or offices. The available connection types are LAN, Dial-up or VPN telecommunication services.

These communication services are provided by a local telecommunication company. Therefore, we have to consider that our clients may use different types of telephone service in their countries. The proposed system provides different quality services to different connection types. The system itself detects the individual connection type and changes the quality of the link.

Most of the bandwidth is occupied by video. Therefore, characteristics of videoconferencing quality have to be defined. The characterization has two parameters. The first is the number of frames per second (fps). This is a measure of how much information is used to store and display motion video. The term applies equally to film video and digital video. Each frame is a still image and displaying frames in quick succession creates the illusion of motion. The more frames per second (fps), the smoother the motion appears. Television in the U.S., for example, is based on the NTSC format, which displays 30 interlaced frames per second (60 picture frame fields per second). In general, the minimum fps needed to avoid jerky motion is about 30. Some computer video formats, such as AVI, provide only 15 frames per second. Macromedia Flash communication server videos can be configured to have from one to any number of frames per second. The second parameter is the resolution of the image. This refers to the sharpness and clarity of an image. In our case the image is a still image of a student or a teacher. This is a characteristic of a video that we are publishing on network clients.

Video is essentially a sequence of images flashed on the screen in rapid succession,giving the illusion of motion. The number of frames displayed every second is known as the frame rate, and it is measured in frames per second (fps). The higher the frame rate, the more frames per second will be used to display the sequence of images, resulting in smoother motion. The trade-off, however, is that higher frame rates require a

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larger amount of data to display the video and therefore more bandwidth.

Figure 1. Client site of the developed software

Figure 1 shows the user interface of client software. Connected clients are shown directly on the left side of the screen. The teacher can easily drag the text on the presentation part. All users can use the text chat to ask questions, except they have an opportunity to make online voice and video chat. Other tools, like whiteboard, file exchange, and dictionary opportunities, are also available for the users.

The system gives some opportunities to clients to receive video or audio of other clients on their screens. This reduces the bandwidth demand to the service provider network.

Other important issues are compatibility between equipment and transmission speed and failures in transmission and room layout [6]. We expect no compatibility problems between sites using the system because we used Macromedia, Inc., products, which support all operating systems (OS) plug-ins. Our system is Web based, and it is not OS dependent, thus avoiding compatibility problems.

Clients from different countries will have different types of connection telecommunication systems. Some will use ISDN and some will use dial-up connections. The system has to be intelligent enough to determine the connection speed of a user. We did this by writing a programming script code for Macromedia Flash. In this way we publish a good quality video streams to clients who have a LAN connection speed (100 MB), and a low quality of streams to clients who have a

dial-up connection to our system. The meaning of high quality here is that we send 100 fps to a client, and for low quality we send between fifteen and thirty fps. This does not affect the smoothness of the motion happening on screen.

As mentioned in the previous section, the live streams and all the actions on the screen are recorded and stored in the database so that the students can access and retrieve recorded lessons later. Each course is assumed to be one hour. Our tests results show that recording a one hour course requires 1.3 GB data to be stored in a database, including all on-screen activities.

We used MYSql Database [8] system as storage unit. To make communication between two software packages, we used PHP [9] script programming language.

For the conference room we provide some tools to the users that are included within the synchronous distance learning environment. These tools include, Discussion Forum, File Exchange, E-mail, Real-time Chat, Video Services, and Whiteboards. All mentioned tools are developed by using flash scripting programming language.

VUofDEU

Oracle Database

e-mail Client

e-mail Server

Redhat Linux

Sendmail

WEB Browser

Chat Client

Chat Server

Windows 2000

Server

PPT Plug-in Java Plug-inMacromedia

Flush Plug-inReal Plug-in

Internet/Intranet

Figure 2. Virtual University Architecture of DEU

Figure 2 illustrates the overall system architecture. The designed system has intelligent archiving of all the motion happening on screen, including the voice. The teacher will be the responsible person during class session. He can manage current sessions which may include more than 20 students. The teacher is able to close all voice sessions with one click. The users also have this option for their bandwidth reduction and do not

Mysql Database

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allow other parties access to video and audio, to use the bandwidth efficiently.

3. Comparison with Other Systems

There are several systems developed by commercial companies and universities for Web-based education and training. For preliminary comparison the following examples have been selected.

• Classnet, developed by Iowa State University Computation Center [10]

• Web-Course-in-a-Box, developed at the Virginia Commonwealth University [11]

• Virtual-U, produced by Simon Fraser University [12]

• WebCT, developed at the University of British Columbia [13]

• Webstudy, a commercial environment for the university market [14]

• Serf, developed at the University of Delaware [15]

The evaluation of these systems is preliminary. The system that has been most widely tested is the WebCT environment from the University of British Columbia. It was tested in cooperation with other universities. From the point of view of features, these systems are mainly concerned with assessing the students rather than creating the resources for authorship and interactivity. Our system will use more tools and resources on the Web than the existing systems. Creating and attending courses through our system seems simpler than through the other systems, but this is a very preliminary comparison that must be confirmed as the communities of users of the various environments grow. Most importantly, our system needs no operator when on line.

4. Conclusion

Modern information technologies, particularly the Internet, present higher education with the capacity to disseminate knowledge to a larger number of people than ever before. To do this, educators use a vehicle now commonly known as distance education.

Our solution gives some opportunities to the users to customize their tool while delivering multimedia on Web. Our system does not need an

administrator after the first setup. The users themselves will be the administrators of the system, since enough hardware requirements are satisfied for the setup. Further work will include the other parts of a virtual university. We believe our solution brings a new level of service to a distance learning community.

References

[1] C. Groeneboer, D. Stockley and T. Calvert, “Virtual-U: A collaborative model for online learning environments”, in Proceedings Second International Conference on Computer Support for Collaborative Learning, Toronto, Canada: December 1997.

[2] WebCT: http://www.webct.com/

[3] K. Okada, F. Maed, Y. Ichikawaa, and Y. Matsushita, “Multiparty Videoconferencing at Virtual Social Distance: MAJIC Design,” in Proceedings of the Conference on Computer-Supported Cooperative Work, Chapel Hill, North Carolina: ACM Press, 1994.

[4] J. J. Cadiz, A. Balachandra, E. Sanocki, A. Gupta, J. Grudin and G. Jancke, “Distance Learning Through Distributed Collaborative Video Viewing,” in Proceedings of the Conference on Computer-Supported Cooperative Work. Philadelphia, PA: ACM Press, 2000.

[5] S. A. Bly, S. R. Harrison and S. Irving, “Media Spaces: Video, Audio and Computing,” Communication of the ACM vol. 36, no. 1, 1993.

[6] lang.swarthmore.edu/neall2000/1b.htm

[7] www.macromedia.com

[8] www.mysql.com

[9] www.php.com

[10] Iowa State University Computation Center: http://classnet.cc.iastate.edu/

[11] Virginia Commonwealth University: http://views.vcu.edu/wcb/intro/wcbintro.html

[12] Simon Fraser University: <http://virtual-u.cs.sfu.ca/vuweb/

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[13] University of British Columbia: http://homebrew.cs.ubc.ca/webct/

[14] http://www.webstudy.com/ (comercial)

[15] University of Delaware: http://www.udel.edu/serf/index.html

About the Authors

Sen Cakir is currently working on probability and statistics through a distance learning class.

Havva Haciogullari Basak is researching e-learning, distributed learning, and multicast in distributed networks.

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