Implementation of and Ada real-time executive: A case study

Current Ada language implementations and runtime environments are immature, unproven and are a key risk area for real-time embedded computer system (ECS). A test-case environment is provided in which the concerns of the real-time, ECS community are addressed. A priority driven executive is selected to be implemented in the Ada programming language. The model selected is representative of real-time executives tailored for embedded systems used missile, spacecraft, and avionics applications. An Ada-based design methodology is utilized, and two designs are considered. The first of these designs requires the use of vendor supplied runtime and tasking support. An alternative high-level design is also considered for an implementation requiring no vendor supplied runtime or tasking support. The former approach is carried through to implementation

Towards the Model-Driven Engineering of Secure yet Safe Embedded Systems

We introduce SysML-Sec, a SysML-based Model-Driven Engineering environment aimed at fostering the collaboration between system designers and security experts at all methodological stages of the development of an embedded system. A central issue in the design of an embedded system is the definition of the hardware/software partitioning of the architecture of the system, which should take place as early as possible. SysML-Sec aims to extend the relevance of this analysis through the integration of security requirements and threats. In particular, we propose an agile methodology whose aim is to assess early on the impact of the security requirements and of the security mechanisms designed to satisfy them over the safety of the system. Security concerns are captured in a component-centric manner through existing SysML diagrams with only minimal extensions. After the requirements captured are derived into security and cryptographic mechanisms, security properties can be formally verified over this design. To perform the latter, model transformation techniques are implemented in the SysML-Sec toolchain in order to derive a ProVerif specification from the SysML models. An automotive firmware flashing procedure serves as a guiding example throughout our presentation.Comment: In Proceedings GraMSec 2014, arXiv:1404.163

An Adaptive Design Methodology for Reduction of Product Development Risk

Embedded systems interaction with environment inherently complicates understanding of requirements and their correct implementation. However, product uncertainty is highest during early stages of development. Design verification is an essential step in the development of any system, especially for Embedded System. This paper introduces a novel adaptive design methodology, which incorporates step-wise prototyping and verification. With each adaptive step product-realization level is enhanced while decreasing the level of product uncertainty, thereby reducing the overall costs. The back-bone of this frame-work is the development of Domain Specific Operational (DOP) Model and the associated Verification Instrumentation for Test and Evaluation, developed based on the DOP model. Together they generate functionally valid test-sequence for carrying out prototype evaluation. With the help of a case study 'Multimode Detection Subsystem' the application of this method is sketched. The design methodologies can be compared by defining and computing a generic performance criterion like Average design-cycle Risk. For the case study, by computing Average design-cycle Risk, it is shown that the adaptive method reduces the product development risk for a small increase in the total design cycle time.Comment: 21 pages, 9 figure

Managing Bias, Partiality, and Dependence in Online Justice Environments.

PhD Theses.As Online Dispute Resolution (ODR) begins to enter the wider market, it promises to substantively change the way arbitration works in the justice eco-system. As such, the justice community must determine the fundamental values to be incorporated into the online justice environment so that it can address ethical and regulatory issues in the design of ODR. This thesis is the first attempt of any ODR scholar to identify the fundamental values that must be embedded in the decision making portion of the ODR process. This thesis advocates for the principle of judicial independence and impartiality: decision makers in the arbitration system must be both impartial and independent, without exception, even if the adherence to this rule of law principle conflicts with maximizing the efficiencies of the overall system. As it relates to the decision making process that incorporates technology within the model, technology driven bias must be identified and mitigated against. Consequently, the ODR system must be examined through the lens of risk identification and mitigation principles. This thesis is the first, to examine the ODR model within the technology driven aspects of model design. This thesis examines Rule of Law within the context of decision making in the online justice environment. The thesis argues for adherence to seven rules of action: (1) the rule of law (RoL) must be protected within the online justice environment; (2) an independent and impartial decision maker is an essential RoL principle, such that no departure from the principle should be allowed; (3) it is the method of ensuring the independence and impartiality of the decision maker that is open for greater debate; (4) it is the model design that mitigates dependence and bias; (5) the reduction of negatively impactful bias is the current “best practice” standard; (6) there must be a human within the final step of the technology driven decision making model; (7) accountability is essential as ODR is part of the justice eco-system. The thesis concludes by creating a first of its kind, best practices guidelines with specific examples of risk identification and mitigation principles that must be built into the design

A Platform-Based Software Design Methodology for Embedded Control Systems: An Agile Toolkit

A discrete control system, with stringent hardware constraints, is effectively an embedded real-time system and hence requires a rigorous methodology to develop the software involved. The development methodology proposed in this paper adapts agile principles and patterns to support the building of embedded control systems, focusing on the issues relating to a system's constraints and safety. Strong unit testing, to ensure correctness, including the satisfaction of timing constraints, is the foundation of the proposed methodology. A platform-based design approach is used to balance costs and time-to-market in relation to performance and functionality constraints. It is concluded that the proposed methodology significantly reduces design time and costs, as well as leading to better software modularity and reliability

Applying ArchOptions to value the payoff of refactoring

ArchOptions is a real-options based model that we have pro-posed to value the flexibility of software architectures in response to future changes in requirements. In this paper, we build on ArchOptions to devise an options-based model, which values the architectural flexibility that results from a refactoring exercise. This value assists in understanding the payoff of investing in refactoring: if the refactored system results in an architecture that is more flexible, such that the expected added value (in the form of options) due to the en-hanced flexibility outweighs the cost of investing in this exer-cise, then refactoring is said to payoff. We apply our model to a refactoring case study from the literature