An architectural framework is proposed to secure the data link layer (Layer 2) in Internet protocol (IP) over Ethernet networks. In this architecture, a new security inter-layering concept, incorporating cryptographic Layer 2 identities, is introduced. Instead of traditional media access control (MAC) addresses, secure and flexible data link layer identifiers are utilized to securely bind Layer 2 and upper layers. In addition, to create security parameters and negotiate identifiers at the data link layer, a key establishment protocol is presented. Moreover, this architecture incorporates the IEEE 802.1AE standard (MACsec) and uses a key hierarchy similar to the IEEE 802.11i standard for future compatibility of wired and wireless networks. Finally, we provide a security analysis of the new data link layer security architecture.

Complex engineering systems involve large numbers of functional elements. Each functional element can exhibit complex behavior itself. Ensuring the ability of such systems to meet the customer's needs and requirements requires modeling the behavior of these systems. Behavioral modeling allows a quantitative assessment of the ability of a system to meet specific requirements. However, modeling the behavior of complex systems is difficult due to the complexity of the elements involved and more importantly the complexity of these elements' interactions. In prior work, formal functional modeling techniques have been applied as a means of performing a qualitative decomposition of systems to ensure that needs and requirements are addressed by the functional elements of the system. Extending this functional decomposition to a quantitative representation of the behavior of a system represents a significant opportunity to improve the design process of complex systems. To this end, a functionality-based behavioral modeling framework is proposed along with a sensitivity analysis method to support the design process of complex systems. These design tools have been implemented in a computational framework and have been used to model the behavior of various engineering systems to demonstrate their maturity, application and effectiveness. The most significant result is a multi-fidelity model of a hybrid internal combustion-electric racecar powertrain that enabled a comprehensive quantitative study of longitudinal vehicle performance during various stages in the design process. This model was developed using the functionality-based framework and allowed a thorough exploration of the design space at various levels of fidelity. The functionality-based sensitivity analysis implemented along with the behavioral modeling approach provides measures similar to a variance-based approach with a computation burden of a local approach. The use of a functional decomposition in both the behavioral modeling and sensitivity analysis significantly contributes to the flexibility of the models and their application in current and future design efforts. This contribution was demonstrated in the application of the model to the 2009 Texas A&M Formula Hybrid powertrain design.

Increasing usage of multi-core processors has led to their use in real time embedded systems (RTES). This entails high performance requirements which may not be easily met when software development follows traditional techniques long used for single processor systems. In this study, parallel programming design patterns especially developed and reported in the literature will be used to improve RTES implementations on multi-core systems. Specific performance parameters will be selected for assessment, and performance of traditionally developed software will be compared with that of software developed using parallel programming patterns.

ABSTRACT OPPORTUNITIES AND BARRIERS OF ARCHITECT LED DESIGN-BUILD PROJECTS Deniz,Ay&ccedil / a M.Sc. in Building Science, Department of Architecture Supervisor: Assoc. Prof. Dr. Soofia Tahira Elias Ozkan September 2012, 77 pages From past to today, technological developments have resulted in new systems in parallel with digital age. Innovations have been started to be replaced with the traditional solutions. Standardizations have also started to be renewed in accordance with the high technology and complexity of the projects. Under these circumstances, design and construction activities have been separated in the construction industry. As a result, alternative project delivery systems have been developed and selecting the right delivery system has gained importance depending upon the complexity of the projects The main objective of this study was to propose a model that supports architect&rsquo / s leadership in design-build systems throughout an international airport project as a case study. Thus, construction industry will gain awareness for the organization structures in which architectural groups lead the other disciplines to achieve success in design-build systems considering time cost quality triangle. In this study, organization charts including project construction process and factors affecting design and construction activities were investigated. The matrix relationship in production level of the organization charts among the project disciplines has been analyzed. According to the evaluation of models reflecting the existing status, alternative models supporting architect&rsquo / s leadership are proposed.

Although widely used, little is known about the nature of expertise involved in functional task analysis, methods used to discover and represent a task structure in terms of goals and subgoals. Training studies indicated that learning task analysis is not trivial. To counter the "task analysis is an art" explanation, this dissertation approached task analysis as a skill acquisition problem that can be understood through scientific inquiry. Two studies were designed to capture and characterize experienced and novice performance. Professional (Study 1) and novice (Study 2) task analysts conducted task analyses on six tasks from two domains (cooking, communication). Master task analyses were created for each task and served as a basis for analysis. Some similar patterns to the task analysis products and errors were observed for the hierarchy dimensions (breadth and depth of analysis), subgoal focus, and versatility. However, differences in separating subgoals (verb-noun pairs) were observed and may be further investigated in the future. Future directions could also focus on understanding the association between the general approach (breadth and depth-first) and the characteristics of the task analysis products. Skill components of functional task analysis were derived from the findings in both studies conducted for this dissertation.

<p>In the area of information systems design it is important to select an appropriate methodology in order to get an information system that functions as expected. The perspective behind the methodology is seldom stated explicitly. The epistemology that a methodology is based on has impacts on the design of the system. Therefore, the process of selecting an appropriate methodology is important. The aim of this work is to study how the process of metamodelling or metathinking is considered in the area of information systems design.</p><p>Interviews and a study of the literature have been performed in order to investigate the awareness of metamodelling thinking in the area of information systems design.In the literature we found that only a small part dealt with the process of metamodelling. The method engineering (ME) approach was found as a way of thinking that seems to consider metamodelling thinking. We have evaluated ME according to a synthesis of the works by van Gigch, Churchman, and Flood and Carson. The evaluation has shown that ME deals with metamodelling thinking. In order to improve the metamodelling thinking in ME, it is important to explicitly define how ME considers the aspect of participation of motivated actors and the iterative process. The interviews have shown that information systems designers use some kind of metamodelling thinking, but they do not seem to be aware of the process.</p><p>In an information system design process, it is important to shift perspectives from reality to modelling, and to the metamodelling level, in order to apply metamodelling thinking. Further work should be performed with the purpose of making the information systems designers aware of the importance of applying metamodelling thinking.</p>

Thesis (Ph.D)--Psychology, Georgia Institute of Technology, 2010. / Committee Chair: Rogers, Wendy; Committee Member: Catrambone, Richard; Committee Member: Charness, Neil; Committee Member: Feldman, Jack; Committee Member: Fisk, Arthur. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Aircraft despatch reliability was the main subject of this research in the wider content of aircraft reliability. The factors effecting dispatch reliability, aircraft delay, causes of aircraft delays, and aircraft delay costs and magnitudes were examined. Delay cost elements and aircraft delay scenarios were also studied. It concluded that aircraft dispatch reliability is affected by technical and non-technical factors, and that the former are under the designer's control. It showed that the costs of aircraft delays are very significant and must be reduced. Cont/d.

Successful Concurrent Engineering (CE) with suppliers requires a pre-disposition on the part of the prime company and the supplier to work in this manner. This thesis explores the impact of design ethos on the implementation of Supplier-inLoop (SIL) CE between an Original Equipment Manufacturer (OEM) and a first tier supplier. Design ethos for the purpose of this thesis is described as 'a characteristic manner or approach to constraints on SIL displayed by personnel involved in the design of new products'. This research employs a mixed-method to understand SIL constraints across industry sectors. A design ethos framework is developed and a military design community is characterised in terms of anomalies to the existing literature. These anomalies are then tested through a questionnaire and then interpreted in terms of the design ethos framework. The results of this comparison show that some characteristics are common to both the civil and military design communities and some are not. A case is made that design ethos, in the context of SIL, is primarily determined by: suppliers' aptitude, skill level and contracts; problems with data I information exchange mechanisms; existing processes, relationships and management support; supplier history; technological view of the product; external influences on the process; existing design milestones; visibility of supplier capability; and, continuity of service in terms of skill and data security. The research concludes that the implementation of SIL is directly impacted by design ethos, and that for SIL to be a success in the military sector design ethos must be managed in line with business objectives. The contribution to knowledge that this thesis provides is the insight it offers into the human issues associated with implementing concurrent engineering with external suppliers, and the identification of sector-specific issues as well as those which will benefit from cross sectoral learning. It is of value to military and civil OEMs for purpose of change management, also to their suppliers in understanding the different needs of military and civil customers when working in a concurrent engmeenng manner.

Contemporary e-learning research often addresses a singular instructional topic, learning strategy, or authoring tool. Technological advancements and evolving delivery methods are changing the e-learning practitioner experience more rapidly than ever before, and the need for a holistic illustration of the modern-day practitioner experience has never been greater. This Interactive Qualitative Analysis (IQA) of the e-learning creation experience consists of Affinity Production Interviews, interviews, and an online survey of e-learning practitioners working with adult audiences. The result of the study is an e-learning creation experience system driven by participants’ stories. The system is comprised of twelve affinities including leadership, policy, the instructional systems design process, the client relationship, emotions, and more. Exercising the system reveals conditions that influence the ultimate outcome of the system: e-learning success. / text