This paper presents a new method for soft error detection using software redundancy (SEDSR) that is able to detect transient faults. Soft errors damage the control flow and data of programs and designers usually use hardware-based solutions to handle them. Software-based techniques for soft error detection force less cost and delay to systems and do not change their configuration. Therefore, these kinds of methods are appropriate alternatives for hardware-based techniques. SEDSR has two separate parts for data and control flow errors detection. Fault injection method is used to compare SEDSR with previous methods of this field based on the new parameter of “Evaluation Factor” that takes in account fault coverage, memory and performance overheads. These parameters are important in real time safety critical applications. Experimental results on SPEC2000 and some traditional benchmarks of this field show that SEDSR is much better than previous methods of this field. SEDSR’s evaluation factor is about 50% better than other methods of this field. These results show its success in satisfaction of the existing tradeoff between fault coverage, performance and memory overheads

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Electronic equipment used in harsh environments such as space has to cope with many threats. One major threat is the intensive radiation which gives rise to Single Event Upsets (SEU) that lead to control flow errors and data errors. In the design of embedded systems to be used in space, the use of radiation tolerant equipment may therefore be a necessity. However, even if the higher cost of such a choice is not a problem, the efficiency of such equipment is lower than the COTS equipment. Therefore, the use of COTS with appropriate measures to handle the threats may be the optimal solution, in which a simultaneous optimization is carried out for power, performance, reliability and cost. In this paper, a novel method is presented for control flow error detection in multitask environments with less memory and performance overheads as compared to other methods seen in the literature.

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A numerical study of separation control has been made to investigate aerodynamic characteristics of a NACA0012 airfoil with a tangential synthetic jet. Simulations are carried out at the chord Reynolds number of Re=1,000,000. The present approach relies on solving the Unsteady Reynolds-Averaged Navier–Stokes (URANS) equations. The turbulence model used in the present computation is the K-ω SST equations. All computations are performed with a finite volume based code. We have varied the synthetic jet position on the suction side of the airfoil at various locations from 4% of the chord all the way up to 60% of the airfoil chord. The jet oscillating frequency of fj = 15 Hz, (which corresponds to the non-dimensional oscillating frequency of Fjet+ = 1 when the jet is placed at the 12% chord location), and the blowing ratio of Vj/U∞ = 2 are used during the control cycle. All the cases considered here are for the airfoil at the constant angle of attack of α = 19°, where the airfoil stalls in the uncontrolled base flow. We found that stall characteristics are significantly improved by controlling the formation of separation vortices in the flow. The airfoil lift is more than doubled by placing the tangential synthetic jet anywhere between 20% chord to 50% chord location. This corresponds to a 25% improvement over the best cases reported by Chapin and Benard (2015) for a cross flow synthetic jet.