NASA-Ames Research Center unstructured technology development

These viewgraphs present an overview and highlights of Cartesian, Prismatic and Hybrid grid generators and flow solvers. Also presented is Tetrahedra grid generation (including surface modeling/gridding)

Multilevel Runtime Verification for Safety and Security Critical Cyber Physical Systems from a Model Based Engineering Perspective

Advanced embedded system technology is one of the key driving forces behind the rapid growth of Cyber-Physical System (CPS) applications. CPS consists of multiple coordinating and cooperating components, which are often software-intensive and interact with each other to achieve unprecedented tasks. Such highly integrated CPSs have complex interaction failures, attack surfaces, and attack vectors that we have to protect and secure against. This dissertation advances the state-of-the-art by developing a multilevel runtime monitoring approach for safety and security critical CPSs where there are monitors at each level of processing and integration. Given that computation and data processing vulnerabilities may exist at multiple levels in an embedded CPS, it follows that solutions present at the levels where the faults or vulnerabilities originate are beneficial in timely detection of anomalies. Further, increasing functional and architectural complexity of critical CPSs have significant safety and security operational implications. These challenges are leading to a need for new methods where there is a continuum between design time assurance and runtime or operational assurance. Towards this end, this dissertation explores Model Based Engineering methods by which design assurance can be carried forward to the runtime domain, creating a shared responsibility for reducing the overall risk associated with the system at operation. Therefore, a synergistic combination of Verification & Validation at design time and runtime monitoring at multiple levels is beneficial in assuring safety and security of critical CPS. Furthermore, we realize our multilevel runtime monitor framework on hardware using a stream-based runtime verification language

Analysing usability and security issues in design and development of information systems

Recent technological advancements and the global economic challenges have meant that, individuals and businesses are constantly seeking new ways to exploit Information Systems (IS) and in manners that not only enhance user experiences and/or improve business processes and productivity, but also protect the individual‟s privacy and business assets for competitive advantage. Therefore, Information Systems need to be designed and developed to meet these challenges and/or other objectives. This thesis will delve primarily into the history of IS as a basis for establishing where the problem(s) lie or emanate from. It will focus on critically analysing existing Information Systems, and investigating the conflicting issues of usability and security, from an Information Systems Design and Development perspective by analysing various approaches. An in-depth review of literature and critical analysis of requirements necessary for the design and development of a usable and secure Information System will be carried out and will form the intellectual framework for this research. The premise therefore, is to look for a balanced approach or appropriate trade-off framework for designing usable-secure systems. The research will conclude with a discussion on how an envisaged conceptual framework or model can be developed based on certain influential factors, and how the framework can be experimentally evaluated, and to suggest areas for further improvement or future research