Sharif Digital Repository

Third generation cellular network technology (3G) can revolutionize communications and data exchanges between many people in a more overwhelming fashion than 2G and 2.5G networks did. The 3G UMTS, the 3G GSM and the 3G GPRS rely on the KASUMI block cipher. Therefore, increasing speed, decreasing power consumption and error detection/correction are the major concerns of the KASUMI algorithm and its generation. On the other hand, Residue Number System is a non-weighted number system and it is currently considered as an important method for high-speed, low-power, parallel and carry-free arithmetic realizations. Redundant Residue Number System is an extension of RNS that also supports error... 

Error propagation analysis is one of the main objectives of fault injection experiments. This analysis helps designers to detect design mistakes and to provide effective mechanisms for fault tolerant systems. However, error propagation analysis requires that the chosen fault injection technique provides a high degree of observability (i.e., the ability to observe the internal values and events of a circuit after a fault is injected). Simulation-based fault injection provides a high observability adequate for error propagation analysis. However, the performance of the simulation-based technique is inadequate to handle today's hardware complexity. As an alternative, FPGA-based fault injection... 

In this paper, an FPGA-controlled fault tolerant back-to-back converter for DFIG-based wind energy conversion application is studied. Before an open-circuit failure in one of the semiconductors, the fault tolerant converter operates as a conventional back-to-back six-leg one. After the fault occurrence in one of the switches, the converter will continue its operation with the remaining five healthy legs. Design, implementation, simulation and experimental verification of a reconfigurable control strategy for the fault tolerant six/five leg converter used in wind energy conversion are discussed. The proposed reconfigurable control strategy allows the uninterrupted operation of the converter... 

In this study, we presented a method for distributing data storage by using residue number system for mobile systems and wireless networks based on peer to peer paradigm. Generally, redundant residue number system is capable in error detection and correction. In proposed method, we made a new system by mixing Redundant Residue Number System (RRNS), Multi Level Residue Number System (ML RNS) and Multiple Valued Logic (MVL RNS) which was perfect for parallel, carry free, high speed arithmetic and the system supports secure data communication. In addition it had ability of error detection and correction. In comparison to other number systems, it had many improvements in data security, error... 

In addition to meeting the real-time constraint, power/energy efficiency and high reliability are two vital objectives for real-time embedded systems. Recently, heterogeneous multicore systems have been considered an appropriate solution for achieving joint power/energy efficiency and high reliability. However, power/energy and reliability are two conflict requirements due to the inherent redundancy of fault-tolerance techniques. Also, because of the heterogeneity of the system, the execution of the tasks, especially real-time tasks, in the heterogeneous system is more complicated than the homogeneous system. The proposed method in this paper employs a passive primary/backup technique to... 

Multicore platforms are becoming the dominant trend in mixed-criticality systems (MCSs). Multicores provide great opportunities to realize task-level redundancy for reliability enhancement. However, they may experience limited utility in battery-powered mixed-criticality embedded systems. Hence, joint energy and reliability management is a crucial issue in designing MCSs. In this article, we propose the low energy standby-sparing mechanism in mixed-criticality system (LESS-MICS) scheme, which uses the inherent redundancy of multicores to apply the standby-sparing technique for fault-tolerance. Also, by using the inherent redundancy, the LESS-MICS scheme proposes the Parallelism and Reduction... 

Multicore platforms are becoming the dominant trend in designing Mixed-Criticality Systems (MCSs), which integrate applications of different levels of criticality into the same platform. A well-known MCS is the dual-criticality system that is composed of low-criticality and high-criticality tasks. The availability of multiple cores on a single chip provides opportunities to employ fault-Tolerant techniques, such as N-Modular Redundancy (NMR), to ensure the reliability of MCSs. However, applying fault-Tolerant techniques will increase the power consumption on the chip, and thereby on-chip temperatures might increase beyond safe limits. To prevent thermal emergencies, urgent countermeasures,... 

This work considers the problem of designing a fault tolerant system for IPMS motor drive subject to current sensor fault. To achieve this goal, two control strategies are considered. The first is based on field oriented control and a developed adaptive backstepping observer which simultaneously are used in the case of fault-free. The second approach proposed is concerned with fault tolerant strategy based on observer for faulty conditions. Stator resistance as possible source of system uncertainty is taken into account under different operating conditions. Current sensors failures are detected and observer based on adaptive backstepping approach is used to estimate currents and stator...