Comparing programming languages is a common topic among programmers and software developers. With the recent changes in programming standards and continual upgrades in hardware design, many new programming languages are being developed, while existing ones are currently going through several enhancements in terms of design and implementation. In this research, we present a comparative study of four programming languages, C, Java, C#, and Jython, with respect to the following criteria: memory consumption, CPU utilization, and execution time. Each test was performed in a distributed system using TCP sockets with 1, 2, 4 and 8 clients, and on a symmetric multiprocessing system.

With computer industry increasingly moving towards network-centric systems, particularly the Internet, competing technologies that help design and develop such systems are fast emerging in the marketplace. The fundamental characteristics of a networked environment are heterogeneity, partial failure, latency and difficulty of "gluing together" multiple, independent processes into a robust, scalable application. JavaSpaces, a shared memory paradigm, provides high-level coordination mechanism for Java easing the burden of creating distributed systems. Large class of distributed problems can be approached using Javaspaces' simple framework. JavaSpaces allows processes to communicate even if each was wholly ignorant of the others. CORBA on the other hand is a standard developed by OMG that allows communication between objects written in different programming languages. It provides common message passing mechanism for interchanging data and discovering services. The purpose of this graduate project was to compare JavaSpaces and CORBA technologies by developing an Insertion Sort and comparing their response times. Javaspaces outpaced CORBA in terms of response time. These technologies make the implementation of distributed algorithms reasonably fault tolerant and highly scalable.

This thesis proposes the design for a prototype device that would be used by Air Traffic Controllers in the radar environment to input tactical Air Traffic Control (ATC) instructions to be sent to aircraft via the Mode S digital data link network. The purpose of the device is to reduce the time required to issue instructions and to eliminate misunderstandings that occur when instructions are issued over voice transmission frequencies. The purpose of this thesis was to develop the device in the most ergonomically suited manner based on the air traffic controller's communications requirements. Digital communications systems include both airborne and ground based components. This project was concerned with the development of the ground-based aspect of the communications system.

In distributed systems design, middleware is a key component. Middleware establishes the communication between a client and server in a multi-tiered architecture. One approach to middleware is implementing the OMG's CORBA standard, through the use of ORBs. Three of the more popular commercially available ORBs are Sun's Java 2 ORB, Borland's VisiBroker for Java, and IONA's Orbix 2000 for Java. The purpose of this graduate project was to compare the three ORBs both quantitatively and qualitatively. The project compares the ORBs quantitatively by measuring the performance of each ORB, in terms of response time. The comparison was done qualitatively by looking at the services each ORB provides, the level of ease of implementing a simple, client-server application in each ORBs' syntax, the time taken to develop each application, difficulties encountered, and the stability of each ORB when tested. The results of the project should prove to be useful for distributed systems designers, and for researchers studying middleware products. In addition, each of the applications created for the project can be re-used for any future performance or load testing of the ORBs one might want to conduct.

As high-speed networks with large bandwidth delay products (BDP) become more common, high-speed transport protocols must be developed that perform well in these contexts. TCP has limitations in high BDP networks. A number of high-speed TCP proposals have emerged, including BIC TCP, High Speed TCP, and H-TCP. XCP is an intraprotocol communication mechanism that promises even greater performance by providing explicit feedback from routers about congestion. It requires changes to routers and end hosts, though, whereas the other experimental protocols only require changes to an end host. We evaluated the performance ofXCP against BIC TCP, High Speed TCP, H-TCP, and . NewReno TCP. We found that in a controlled environment, XCP gave much better performance than the other TCPs. XCP was sensitive to misconfiguration and environmental factors, though, and was more difficult to deploy. More work is required to make XCP more stable. The other TCPs did not perform better than NewReno TCP but show promise, as most performed almost as well as NewReno TCP.

Linda is a new parallel programming language that is built around an interprocess communication model called generative communication that differs from previous models in specifying that shared data be added in tuple form to an environment called tuple space, where a tuple exists independently until some process chooses to use it. Interesting properties arise from the model, including space and time uncoupling as well as structured naming. We delineate the essential Linda operations, then discuss the properties of generative communication. We are particularly concerned with implementing Linda on top of two traditional parallel programming paradigms - process communication through globally shared memory via monitors, and process communication in local memory architectures through the use of message passing constructs. We discuss monitors and message passing, then follow with a description of the two Linda implementations.

Communication between various broadcast equipment plays a major role in the daily operation of a typical broadcast facility. For example, editing equipment must interface with tape machines, production switchers must interface with font generators and video effect equipment, and satellite ground controllers must interface with satellite dishes and receivers. Communication between these devices may be a simple hardware handshake configuration or a more elaborate software based communications via serial or parallel interfacing. This thesis concerns itself with the software interfacing needed to allow various dissimilar types of equipment to communicate, and therefore, interface with each other. The use of Simple Network Management Protocol (SNMP) in a non-typical manner for the purpose of hardware interfacing is the basis for this work.

Over time, advances in database technology and utilization have resulted in a rapid increase in the number and types of data sources. Simultaneously, numerous methods of unifying these various data sources have emerged. Research has shown that a more comprehensive set of data attribute matches between multiple schemas can be detected by combining a number of the unification methodologies as opposed to using a single method. In this research project, a unification framework, dbUNiFier, has been proposed as an approach to allow for easy integration of both existing and future unification methods and data sources.

The purpose of this thesis is to compare the performance characteristics of Simple Object Access Protocol (SOAP) and Representational State Transfer (REST), which are methods of supporting interactions among Web services. They differ in both context and usage; SOAP is a protocol while REST is architecture. SOAP is a well-developed protocol used in the Web industry and is standardized by the World Wide Web Consortium (W3C). REST is the outcome of Dr. Roy Thomas Fielding’s 2000 PhD dissertation, “Architectural Styles and the Design of Network-Based Software Architecture.” REST is gaining in popularity due to its simplicity, scalability, and architectural dependence on the World Wide Web. Major software companies, such as Google and Amazon, among others, have started using REST. The main difference between the two methods is SOAP is a tightly coupled system, whereas REST is a loosely coupled system; both have advantages and disadvantages. We built SOAP and REST based Web services that performed the GET, POST, PUT, and DELETE functions on a database. We utilized response time and throughput metrics to compare the performance of these Web services. In comparing the two technologies, we found REST was considerably faster, compared to SOAP, because the response times of REST were better than those of SOAP. As an ancillary outcome, we found building Web services using SOAP was easier, due to considerable tool support, whereas developing Web services using REST was time consuming, as it provides no tool support.

Security is very important in present day life. In this highly-interconnected world, most of our daily activities are computer based, and the data transactions are protected by passwords. These passwords identify various entities such as bank accounts, mobile phones, etc. People might reuse the same password, or passwords related to an individual that can lead to attacks. Indeed, remembering several passwords can become a tedious task. Biometrics is a science that measures an individual’s physical characteristics in a unique way. Thus, biometrics serves as a method to replace the cumbersome use of complex passwords. Our research uses the features of biometrics to efficiently implement a biometric encryption system with a high level of security.