As Virtual Environments (VE) become a more commonly used method of interaction and presentation, supporting users as they navigate and interact with scenarios presented in VE will be a significant issue. A key step in understanding the needs of users in these situations will be observing them perform representative tasks in a fully developed environment. In this paper, we describe the development of a test bed for interactive narrative in a virtual environment. The test bed was specifically developed to present multiple, simultaneous sequences of events (scenarios or narratives) and to support user navigation through these scenarios. These capabilities will support the development of multiple users testing scenarios, allowing us to study and better understand the needs of users of narrative VEs.

A large number of applications like multi-player games, video conferencing, chat groups and network management are presently based on multicast communication. As the group communication model is being deployed for mainstream use, it is critical to provide security mechanisms that facilitate confidentiality, authenticity and integrity in group communications. Providing security in multicast communication requires addressing the problem of scalability in group key distribution. Scalability is a concern in group communication due to group membership dynamics. Joining and leaving of members requires the distribution of a new session key to all the existing members of the group. The two approaches to key management namely centralized and distributed approaches are reviewed. A hybrid solution is then provided, which represents a improved scalable and robust approach for a secure multicast framework. This framework then is implemented in an example application of a multicast news service.

Streaming multimedia content with UDP has become popular over distributed systems such as an Internet. This may encounter many losses due to dropped packets or late arrivals at destination since UDP can only provide best effort delivery. Even UDP doesn't have any self-recovery mechanism from congestion collapse or bursty loss to inform sender of the data to adjust future transmission rate of data like in TCP. So there is a need to incorporate various control schemes like forward error control, interleaving, and congestion control and error concealment into real-time transmission to prevent from effect of losses. Loss can be repaired by retransmission if roundtrip delay is allowed, otherwise error concealment techniques will be used based on the type and amount of loss. This paper implements the interleaving technique with packet spacing of varying interleaver block size for protecting real-time data from loss and its effect during transformation across the Internet. The packets are interleaved and maintain some time gap between two consecutive packets before being transmitted into the Internet. Thus loss of packets can be reduced from congestion and preventing loss of consecutive packets of information when a burst of several packets are lost. Several experiments have been conducted with …

The purpose of telecommunication network configuration optimization is to find the best homing relationship between tandems and switches so as to minimize interswitch traffic, or equivalently to maximize intraswitch traffic. Note that, since minimal interswitch traffic implies minimal IMT utilization, communication costs will also be minimal.

This problem is intended to be an introduction to the design of a software system which translates PDP-8 assembly language source into it's machine-readable object code. This assembler runs on the IBM 360/50. It is assumed that the reader is familiar with the basic PDP-8 assembly language. For the description and use of this assembler the reader is referred to the PAL-III SYMBOLIC ASSEMBLER PROGRAMMING MANUAL from DEC (order number DIGITAL 8-3-5, Digital Equipment Corporation: Maynard, Massachusetts, 1965.). The Second problem of the study concerns the design of a simulator for the PDP-8 computer.

The purpose of this project is 1) to create a Thai character set for text processing, 2) to write a text processing program for the character set, and 3) to allow users to create and save the text.

This is a report concerning the project I completed for my 590 (special problem) credit. The subject of this project was a system for interactive practice room scheduling by music students at NTSU. This system was created in the fall semester of 1982 as a class project for software Development (CSCI 553) with Dr. Irby. The system was not completely finished, and I received permission from Dr. Irby to finish it and help implement its use at the Music department. I was able to observe three usages of the system: Spring, Summer I, and Summer II semesters of 1983. This report details the problems encountered during each of these usages, and changes made to the system due to them. Results of a first-use survey, under documentation, and complete final code listings were also included.

The objective of this work is to help the faculty, staffs and students of NTSU to use the CalComp plotting facility very easily. Therefore, this work is written in such a step by step and self-explanatory way to help the reader to understand and grasp the essential technique of the computer plotting. Each subroutine illustrated in this work has been run and checked by our NTSU computer-CalComp plotting facility; the results of sample programs and illustrated graphs are believed to be very useful to understand each individual subroutine. Basically, software packages are stored in the magnetic disk of the IBM 360 computer as the standard graphic subroutines. These subroutines were written in FORTRAN IV. The user can write the driving program to call these subroutines and also inputs the desire data to the computer for computation. The results of computation will be outputed and stored in the magnetic tape.

PILOT (Programmed Inquiry, Learning or Teaching) is a simple, conversational language developed in 1969 by John A. Starkweather at the University of California Medical Center in San Francisco. Originally designed for computer assisted instructional needs, PILOT also has been effectively used as an introductory computer language. The PILOT system developed for the Apple II microcomputer consists of two programs, PILOT EDITOR and PILOT DRIVER, which are written in Applesoft and which use the Apple II disk operating system. The PILOT system was designed to facilitate easy authoring and execution of programs written in an extended version of the PILOT language. Due to the memory requirements of the programs and the Apple II disk operating system, the PILOT system described here should be executed on a machine with at least 32k bytes of random access memory.

Among the early applications of computers, one can find frequent mention of intelligent instructional systems. Such intelligent instructional systems represent a new generation of learner-based computer aided instruction, preceded in time by the original frame-based systems and an intervening generation of expert-based CAI. The history of CAI is characterized by three generations: Frame-based CAI, Expert-based CAI and Learner-based CAI.

Secure communication is the primary challenge in today's information network. In this project an efficient secret key agreement protocol is described and analyzed along with the other existing protocols. We focus primarily on Leighton and Micali's secret-key agreement without the use of public-key encryption techniques. The Leighton-Micali protocol is extremely efficient when implemented in software and has significant advantages over existing systems like Kerberos. In this method the secret keys are agreed upon using a trusted third party known as the trusted agent. The trusted agent generates the keys and writes them to a public directory before it goes offline. The communicating entities can retrieve the keys either from the online trusted agent or from the public directory service and agree upon a symmetric-key without any public-key procedures. The principal advantage of this method is that the user verifies the authenticity of the trusted agent before using the keys generated by it. The Leighton-Micali scheme is not vulnerable to the present day attacks like fabrication, modification or denial of service etc. The Leighton-Micali protocol can be employed in real-time systems like smart cards. In addition to the security properties and the simplicity of the protocol, our experiments show that in …

Online airline ticket booking system is one of the essential applications of E-commerce. With the development of Internet and security technology, more and more people begin to consume online, which is more convenient and personal than traditional way. The goal of this system is to make people purchase airline tickets easily. The system is written in JAVATM. Chapter 1 will introduce some basic conception of the technologies have been used in this system. Chapter 2 shows how the database and the system are designed. Chapter 3 shows the logic of the Web site. In Chapter 4 the interface of the system will be given. Chapter 5 tells the platform of this system.

The author's primary goal is to begin research leading ot the attainment of a low cost computer/music system which will allow the composer to write polyphonic music of up to eight voices into a computer through a terminal, and have the music played back by means of computer synthesized sound or by means of a conventional synthesizer controlled by a computer via digital-to-analog converters. The goal system will allow the composer to retreat and hear his product objectively as the painter steps back to review his canvas.