published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / toc / Educational Psychology / Master / Master of Social Sciences

published_or_final_version / Computer Science / Master / Master of Philosophy

High-level programming language features simplify software development by eliminating many low-level programming concerns and by providing programmers with useful abstractions to simplify description and analysis of their programs. This dissertation discusses briefly some of the special needs of structural pattern-matching programs that must execute in real time and suggests language features to support these needs. These language features are implemented in an experimental version of the Icon programming language and examples of how these language features can be used are presented. This dissertation also presents and discusses the implementation of these language mechanisms, including the implementation of a new algorithm for garbage collecting linked data structures and strings in real time. One of the new language features is a stream data type, which allows programmers to perform pattern matching directly on sequences of data values produced by external sources, without requiring explicit read operations to bring the data into memory before analyzing it. Other new language features provide the ability to create and manipulate concurrent Icon processes, between which the stream data type serves as the principal mechanism for interprocess communication. Stream and concurrent process manipulation mechanisms integrate naturally with each other and with the existing mechanisms of the Icon programming language. Sequential Icon programs are, for the most part, unaffected by the new language capabilities.

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Approved for public release, distribution unlimited / Currently under development, the Global Information Grid (GIG) Enterprise Services (ES) is a suite of capabilities intended to provide improved user access to mission-critical data via Web-based and network technologies. Some of the problems of implementing such capabilities include non-uniform data formats, incompatible run-time environments and nonstandard proprietary applications, all of which block operational interoperability. Web services are specifically designed to address the interoperability challenges of a service-oriented architecture (SOA) such as the GIG. SOAs are networked infrastructures that are designed to facilitate the interoperability of collections of services without requiring service context awareness. Standards-based Web services provide the necessary flexibility and extensibility to ensure information flow is platform, run-time and software independent. The proof of concept (POC) software example developed for this research demonstrates the flexibility and extensibility of standards-based, operating-system-independent Web services. The result is an experimental endeavor to provide a mock operation command center information portal, which provides a notional summary personnel status report to the commander in real-time from a Web service that was originally generated by a stand-alone client/server system. The POC is developed with great attention to open-source technologies and open-standards compliance. The key technologies involved are Extensible Markup Language (XML), the Java programming language, PHP: Hypertext Preprocessor (PHP) scripting language and Simple Object Access Protocol (SOAP). This work demonstrates the benefits of leveraging Web services to unlock legacy specialized applications to enhance the Warfighter's battlespace awareness by improving information flow via a Web based information portal. / Captain, United States Marine Corps

Approved for public release; distribution is unlimited / Currently, the most common approach in developing database applications is to use an object-oriented language for the frontend module and a relational database for the backend datastore. The major disadvantage of this approach is the well-known "impedance mismatch" in which some form of mapping is required to connect the objects in the frontend and the relational tuples in the backend. Java Data Objects (JDO) technology is recently proposed Java API that eliminates the impedance mismatch. By using JDO API, the programmers deal strictly with objects. JDO hides the details of the backend datastore by providing the object-oriented view of the datastore. JDO automatically handles the mapping between the objects and the underlying data in the relational database, which is hidden from the programmer. This thesis investigates the effectiveness of JDO. Part of the analysis will develop a database application using JDO. Although JDO provides the benefits of object-orientation in design and implementation of the databases, it is not immune from problems and limitations. The thesis will also analyze the advantages and disadvantages of using JDO and discuss the areas requiring improvements in future releases. / Major, Hellenic Air Force