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This paper presents first results from research into open source projects from a software engineering perspective. The research methodology employed relies on public data retrieved from the CVS-repository of the GNOME project and relevant discussion groups. This methodology is described in detail and some of the results concerning the special characteristics of open source software development are given. (author's abstract) / Series: Diskussionspapiere zum Tätigkeitsfeld Informationsverarbeitung und Informationswirtschaft

Although markets are emerging for commercial off-the-shelf components (such as Sun JavaBeans), there are many barriers to widespread component adoption. This is due to the inherent `black-box' nature of software components: developers have no knowledge or control of the component's internal characteristics. Without source or design details, developers only have the component's interface, documentation and test results to answer important questions about reliability, proper use, behavior andperformance. The current best practice of specifying a component's capabilities by providing only the syntax and informal documentation is insufficient to assemble mission or safety-critical systems successfully. To address these problems we have developed a framework forcreating and analyzing the concise specifications of components and their related interfaces. The framework extends a formal model for software architecture descriptions to support the specification of a range of terms. With formal component specifications developers can use the framework to analyze the properties of individual components or of entire systems. Unlike other approaches, the formal basis and implementation of our framework enhance understanding and automates much of thecomponent analysis process.

This work brings together two fundamental ideas for modelling, programming and analysing software systems. The first idea is of a methodological nature: engineering software by systematically creating and relating languages. The second idea is of a technical nature: using patterns as a practical foundation for computing. The goal is to show that the systematic creation and layering of languages can be reduced to the elementary operations of pattern matching and instantiation and that this pattern-based approach provides a formal and practical foundation for language-driven modelling, programming and analysis. The underpinning of the work is a novel formalism for recognising, deconstructing, creating, searching, transforming and generally manipulating data structures. The formalism is based on typed sequences, a generic structure for representing trees. It defines basic pattern expressions for matching and instantiating atomic values and variables. Horizontal, vertical, diagonal and hierarchical operators are different ways of combining patterns. Transformations combine matching and instantiating patterns and they are patterns themselves. A quasiquotation mechanism allows arbitrary levels of meta-pattern functionality and forms the basis of pattern abstraction. Path polymorphic operators are used to specify fine-grained search of structures. A range of core concepts such as layering, parsing and pattern-based computing can naturally be defined through pattern expressions. Three language-driven tools that utilise the pattern formalism showcase the applicability of the pattern-approach. Concat is a self-sustaining (meta-)programming system in which all computations are expressed by matching and instantiation. This includes parsing, executing and optimising programs. By applying its language engineering tools to its own meta-language, Concat can extend itself from within. XMF (XML Modeling Framework) is a browser-based modelling- and meta-modelling framework that provides flexible means to create and relate modelling languages and to query and validate models. The pattern functionality that makes this possible is partly exposed as a schema language and partly as a JavaScript library. CFR (Channel Filter Rule Language) implements a language-driven approach for layered analysis of communication in complex networked systems. The communication on each layer is visible in the language of an “abstract protocol” that is defined by communication patterns.

Approved for public release, distribution unlimited / Underwater Acoustic Networks (UANs) hold enormous potential for both military and civilian applications. However, current networking protocols implemented are often sub-optimal, resulting in severely underutilized networks. We believe one of the key reasons for this shortcoming is a lack of good underwater acoustic propagation models for simulation packages used to evaluate UAN protocols. This thesis addresses this problem by developing a computationally-efficient approximation of a sophisticated analytical model called Monterey-Miami Parabolic Equation model (MMPE). The approximation can then be used to support UAN simulations. The characteristics of the problem make a statistical approach the methodology of choice for this study. Data was generated using the MMPE model. The data was used to develop a much less complex approximation for which an OpNet simulation module could be developed. The latter allows UAN operation to be modeled over a collection of nodes and over an interval of time, rather than a single point in time between two specific nodes, as modeled by the original equation. The result of this research can enable a more complete analysis of network enabling protocols and support more informed decisions regarding the appropriate node topology and protocols to use in order to increase network performance.

The success of formal specifications and reactive systems is highly dependant on the formal specification language being used. To date, the most common approach to this problem involves two activities: (i) the specification activity, where correctness properties are specified, and (ii) verification activity, where the system under review is proven to satisfy those properties. Typically, some form of temporal logic or regular expression language is used to specify the correctness properties; properties that are specified for given states of the system under review. This means that specification is partial and is done after system design, prototyping, or coding. Temporal logics have been found to be unsuitable for early specification. This thesis investigates the suitability of TLCharts, a specification language that combines statecharts and temporal logic, for the early specification of the dynamic characteristics of a homing torpedo. In order to achieve the task, a fictitious homing torpedo example, called KTorp, is used. Using a systematic approach, we developed deterministic statecharts and non-deterministic TLCharts for the KTorp control software. Our case study shows that using TLCharts as the early specification language for weapon systems software provides efficient, visual and intuitive specifications.

"Each computer on a network has an OS Fingerprint that can be collected through various applications. Because of the complexity of network systems, vulnerabilities and exploitations of the same to gain access to systems will always be a problem. Those wishing to attack a system can use the OS Fingerprint to identify the types of vulnerabilities and software exploits that will be effective against the system. This paper discusses how system vulnerabilities become exploited and used by network attackers. Because OS Fingerprints are one of many tools network attackers will use to identify and attack a system, concealing a system's OS Fingerprint becomes an important part of securing that system. To demonstrate the capability of concealing the OS Fingerprint of a system, a prototype system was developed. This prototype changed the OS Fingerprint of a Linux system so that it matched a Windows NT system.

This research addresses the need for a pacemaker/defibrillator that could perform an automatic system self-diagnostics check to assure operational functionality and give doctors a chance to assess a patient's status in the event they are experiencing complications, as pointed out in an article in the journal Health Scout, which stated that 'St. Jude Medical Inc., the nation's second-largest pacemaker manufacturer, has warned doctors that at least 90 of its pacemakers being used by heart patients could stop emitting the electrical signal that regulates heartbeat'. The proposed functionality would also serve the military in determining the whereabouts or state of being of an individual on the battlefield. This thesis investigates the use of Unified Modeling Language (UML) Diagrams, Object-Oriented Analysis and Design, and Structured Query Language (SQL) to develop the high level architecture of a system to store and retrieve digital/wireless communication information from a pacemaker/defibrillator, or other device, and to alert medical personnel when a person is experiencing problems with their health. It presents the requirements and architectural design of the Self-Diagnostics Digitally Controlled Pacemaker/Defibrillator Device. Applications of the SDDCPDD design concept for military missions are explored.

The installation process for afloat systems is very stringent. This rigor is necessary to ensure the Warfighters can fully utilize the functionality provided by information technology (IT) aboard a ship, especially when underway -- removed from most technical support and assistance. However, this rigor also increases the difficulty of executing an afloat installation. The purpose of this thesis is to document the lessons learned from the installation of the Ocean Surveillance Information System (OSIS) Evolutionary Development (OED) on board the USS Blue Ridge (LCC-19). OED is an ashore multi-level secure (MLS) command and control and intelligence (C2I) computer system that is fielded at the Joint Intelligence Centers and Joint Analysis Centers. The MLS aspect of OED allows the operator to view and add value to data from multiple security domains on one workstation. In the space, weight, and power (SWAP) constrained environment of a ship, this technology is very advantageous. Since OED is an ashore system, this afloat installation presented a number of challenges and a unique perspective into the installation process. This thesis documents these challenges, how they were overcome and provides future installers recommendations to improve the planning of future afloat installations.

The Configurable Fault Tolerant Processor (CFTP) team at Naval Postgraduate School (NPS), Monterey, was created to develop, test, and implement reliable computing solutions for the space environment. The CFTP team seeks to design reliable circuits using Field Programmable Gate Arrays (FPGA) to include designs that mitigate the radiation hazards posed to FPGAs. A significant challenge faced by the CFTP team has been the integration and subsequent software development of the CFTP architecture, which includes a "Controller" and an "Experiment" FPGA. This thesis investigates some of the specific design issues that must be considered for future experiments, to include timing between the two FPGAs, and data throughput of the CFTP architecture. Procedures for the development and implementation of experiments are detailed for the benefit of future experimenters who may be new to designing for FGPAs. Lastly, the Controller program is streamlined such that only minor modifications are required by prospective users in order to conform to specific experiments. Over the years the CFTP team has produced several experiments that will provide reliable computing solutions for the space environment. Now, in addition to the "what" is to be used in space, this thesis presents "how" to run them in space.