This thesis details the integration of a common collaboration technique, desktop sharing, into a virtual world environment. Previous literature shows no intersection between these fields. This thesis will illustrate that existing collaboration technology can be integrated into virtual worlds with a minimal amount of effort. Outlined in this thesis are the developmental and procedural challenges encountered in demonstrating seamless desktop sharing in a virtual environment and a stress test of the integrated system revealing that the inclusion of desktop sharing resulted in minor performance loss. The Problem Current virtual world technology has limited capability for collaboration because of a lack of collaboration tools. This thesis proposes that it is feasible to take a common collaboration tool such as desktop sharing and introduce it into a virtual world. / Department of Computer Science

Tuning a computer system effectively requires prior studies on the performance of the system. There are different types of tools available to measure a system: hardware, firmware and software. This thesis presents the design and implementation of an event monitor, which is one type of software tools. The event monitor was developed on a SUN1 workstation running UNIX 4.2bsd version 1.4. Six types of events were selected to be measured, namely transactions, logins/logouts, pageins, pageouts, disk I/Os and forks/exits. The operating system was modified to include probes to trap these events. For a final testing of the event monitor, it was ported and installed onto a SUN3 workstation running UNIX 4.2bsd version 3.2. Measurements collected were analyzed by a capacity planning package condenser. The results give an indication of the system workload and the system performance. Benchmarks were also set up to measure the overhead incurred by the event monitor. / Science, Faculty of / Computer Science, Department of / Graduate

A performance experiment on a PDP 11/45 running under UNIX is described. The purpose is to discover the major influences in the system and their relationships in an attempt to analyze the performance of the system and predict the effect on performance of possible hardware and workload changes. A suitable performance parameter is developed and the workload, hardware and internal system parameters are determined. Tools are constructed to record these parameters. A controlled experiment, using a synthetic workload is then conducted. The results are analyzed using regression analysis and suitable equations are obtained. Sample applications are given. The merits of the relationships, as well as the suitability of the tools developed and methods used, are discussed. / Science, Faculty of / Computer Science, Department of / Graduate

Well replicated tree-ring samples were collected, dated and measured for California west of the Sierra Nevada, eastern Oregon and the northern Great Basin. A computer program was developed and used to check crossdating quality. Another computer program to generate and analyze tree-ring chronologies was evaluated, further developed cooperatively and used to produce chronologies for the dated site collections. This report contains these site chronologies in three versions along with site descriptions and chronology statistics. Users manuals are included for the two computer programs. The effect on a chronology of poor crossdating is discussed, and a study of standardization of tree-ring measurement series is reported. Some new techniques are described for processing tree-ring samples.

Database and database technology are having a major impact on the growing use of computers. The rising popularity of database systems for the management of data has resulted in an increasing number of systems. As the number grows, the difficulty in choosing the system which will best meet the requirements of a particular application also increases. Knowing how to choose the correct one for a given application is important.The purpose of this thesis is to compare two very commonly used Database Management Systems (ORACLE and RDB) at Ball State University by describing and listing the advantages of each of them as well as their weaknesses, giving a comprehensive study of their performances, user friendliness, limits, and to aid users and managers in obtaining a deeper knowledge of these two systems. / Department of Computer Science

Databases and database technology are having a major impact on the growing use of computers. It is fair to say that databases are playing a critical role in almost all areas where computers are used, including business, engineering, medicine, law, education, and library science, to name a few.At Ball State University, databases are very widely used among faculty, staff, and students. The common commercial database management system (DBMS) used in the university is ORACLE. Due to the extensive use of the system and the availability and easy access to alternative systems such as RDB/VMS, a comparative research is in order.This thesis is a comprehensive comparison between the two systems. It covers the differences in design, SQL codings, and the use of host programming language such as FORTRAN. It concentrates on the differences in memory usage, execution time, as well as the CPU time needed to precompile, link, and run. / Department of Computer Science

As Voice over IP becomes more prevalent, value-adds to the service will become ubiquitous. Voice over IP (VoIP) is no longer a single service application, but an array of marketable services of increasing depth, which are moving into the non-desktop market. In addition, as the range of devices being generally used increases, it will become necessary for all services, including VoIP services, to be accessible from multiple platforms and through varied interfaces. With the recent introduction and growth of the open source software PBX system named Asterisk, the possibility of achieving these goals has become more concrete. In addition to Asterisk, a number of open source systems are being developed which facilitate the development of systems that interoperate over a wide variety of platforms and through multiple interfaces. This thesis investigates Asterisk in terms of its viability to provide the depth of services that will be required in a VoIP environment, as well as a number of other open source systems in terms of what they can offer such a system. In addition, it investigates whether these services can be made available on different devices. Using various systems built as a proof-of-concept, this thesis shows that Asterisk, in conjunction with various other open source projects, such as the Twisted framework provides a concrete tool which can be used to realise flexible and protocol independent telephony solutions for a small to medium enterprise.

To support current and emerging database applications, Object-Relational Database Management Systems (ORDBMS) provide mechanisms to extend the data storage capabilities and the functionality of the database with application-specific types and methods. Using these mechanisms, the database may contain user-defined data types, large objects (LOBs), external procedures, extensible indexing, query optimisation techniques and other features that are treated in the same way as built-in database features . The many extensibility options provided by the ORDBMS, however, raise several implementation challenges that are not always obvious. This thesis examines a few of the key challenges that arise when extending Oracle database with new functionality. To realise the potential of extensibility in Oracle, the thesis used the problem area of image retrieval as the main test domain. Current research efforts in image retrieval are lagging behind the required retrieval, but are continuously improving. As better retrieval techniques become available, it is important that they are integrated into the available database systems to facilitate improved retrieval. The thesis also reports on the practical experiences gained from integrating an extensible indexing scenario. Sample scenarios are integrated in Oracle9i database using the data cartridge mechanism, which allows Oracle database functionality to be extended with new functional components. The integration demonstrates how additional functionality may be effectively applied to both general and specialised domains in the database. It also reveals alternative design options that allow data cartridge developers, most of who are not database server experts, to extend the database. The thesis is concluded with some of the key observations and options that designers must consider when extending the database with new functionality. The main challenges for developers are the learning curve required to understand the data cartridge framework and the ability to adapt already developed code within the constraints of the data cartridge using the provided extensibility APls. Maximum reusability relies on making good choices for the basic functions, out of which specialised functions can be built. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in

Typescript (photocopy). / Digitized by Kansas Correctional Industries

With network enabled consumer devices becoming increasingly popular, the number of connected devices and available services is growing considerably - with the number of connected devices es- timated to surpass 15 billion devices by 2015. In this increasingly large and dynamic environment it is important that users have a comprehensive, yet efficient, mechanism to discover services. Many existing wide-area service discovery mechanisms are centralised and do not scale to large numbers of users. Additionally, centralised services suffer from issues such as a single point of failure, high maintenance costs, and difficulty of management. As such, this Thesis seeks a Peer to Peer (P2P) approach. Distributed Hash Tables (DHTs) are well known for their high scalability, financially low barrier of entry, and ability to self manage. They can be used to provide not just a platform on which peers can offer and consume services, but also as a means for users to discover such services. Traditionally DHTs provide a distributed key-value store, with no search functionality. In recent years many P2P systems have been proposed providing support for a sub-set of complex query types, such as keyword search, range queries, and semantic search. This Thesis presents a novel algorithm for performing any type of complex query, from keyword search, to complex regular expressions, to full-text search, over any structured P2P overlay. This is achieved by efficiently broadcasting the search query, allowing each peer to process the query locally, and then efficiently routing responses back to the originating peer. Through experimentation, this technique is shown to be successful when the network is stable, however performance degrades under high levels of network churn. To address the issue of network churn, this Thesis proposes a number of enhancements which can be made to existing P2P overlays in order to improve the performance of both the existing DHT and the proposed algorithm. Through two case studies these enhancements are shown to improve not only the performance of the proposed algorithm under churn, but also the performance of traditional lookup operations in these networks.