Anees Ullah

Bio: Anees Ullah is an academic researcher from University of Engineering and Technology, Peshawar. The author has contributed to research in topic(s): Field-programmable gate array & Control reconfiguration. The author has an hindex of 8, co-authored 31 publication(s) receiving 213 citation(s). Previous affiliations of Anees Ullah include City University of Science and Information Technology & Case Western Reserve University.

Comparison Based Analysis of Different Cryptographic and Encryption Techniques Using Message Authentication Code (MAC) in Wireless Sensor Networks (WSN)

Abstract: Wireless Sensor Networks (WSN) are becoming popular day by day, however one of the main issue in WSN is its limited resources. We have to look to the resources to create Message Authentication Code (MAC) keeping in mind the feasibility of technique used for the sensor network at hand. This research work investigates different cryptographic techniques such as symmetric key cryptography and asymmetric key cryptography. Furthermore, it compares different encryption techniques such as stream cipher (RC4), block cipher (RC2, RC5, RC6 etc) and hashing techniques (MD2, MD4, MD5, SHA, SHA1 etc). The result of our work provides efficient techniques for communicating device, by selecting different comparison matrices i.e. energy consumption, processing time, memory and expenses that satisfies both the security and restricted resources in WSN environment to create MAC.

An error-detection and self-repairing method for dynamically and partially reconfigurable systems

Abstract: Reconfigurable systems are gaining an increasing interest in the domain of safety-critical applications, for example in space and avionic applications. In fact, the capability of reconfiguring the system during run-time execution and the high computational power of modern Field Programmable Gate Arrays (FPGAs) makes these devices suitable for data processing. Moreover, such systems must also guarantee the abilities of self-awareness, self-diagnosis and self-repair in order to cope with errors due to the harsh conditions typically existing in some environments. In this paper we propose a self-repairing method for partially and dynamically reconfigurable systems applied at a fine-grain granularity level. Our method is able to recover and correct errors using the run-time partial reconfiguration capabilities offered by modern SRAM-based FPGAs. Fault injection experiments have been executed on a dynamically reconfigurable system embedding a number of benchmark circuits. Results demonstrate that the method can achieve full detection of single and multiple errors, while significantly improving the system availability with respect to traditional error detection and correction methods.

On the optimal reconfiguration times for TMR circuits on SRAM based FPGAs

Abstract: Unreliable and harsh environmental conditions in avionics and space applications demand run-time adaptation capabilities to withstand environmental changes and radiation-induced faults. Modern SRAM-based FPGAs integrating high computational power with partial and dynamic reconfiguration abilities are a usual candidate for such systems. However, due to the vulnerability of these devices to Single Event Upsets (SEUs), designs need proper fault-handling mechanisms. In this work we propose a novel circuit instrumentation method for probing Triple Modular Redundancy (TMR) circuits for error detection at the granularity of individual domains and then use selective run-time dynamic reconfiguration for recovery. Error detection logic is inserted in the physical net-list to identify and localize faults. Moreover, selective domain reconfiguration is achieved by careful considerations in the placement phase on the FPGA reconfigurable area. The proposed technique is suitable for systems having hard real-time constraints. Our results demonstrate that this approach has an overhead of 2 LUTs per majority voter in internal partitions in terms of area when compared to the standard TMR circuits. In addition, it brings down the reconfiguration times of TMR circuits to a single domain and ensures a 100% availability of the device assuming the Single Event Upset fault model.

PR-TCAM: Efficient TCAM Emulation on Xilinx FPGAs Using Partial Reconfiguration

Abstract: Modern field-programmable gate arrays (FPGAs) provide a vast amount of logic resources that can be used to implement complex systems while providing the flexibility to modify the design once deployed. This makes them attractive for software-defined networks (SDNs) applications, and, in fact, most vendors provide the building blocks needed for those applications, which include basic packet classification functions such as exact match, longest prefix match, and match with wildcards. Those are needed for different functions such as routing, security filtering, monitoring or quality of service. The match with wildcards can be done using ternary content addressable memories (TCAMs). TCAMs can be implemented as independent standalone devices or as Internet Protocol (IP) blocks that are used inside networking application-specific integrated circuits (ASICs) such as switching ICs. In both cases, the cells of a TCAM are more complex than that of a normal memory and also than that of a binary content addressable memory (CAMs). This is due to the more complex matching that they need to implement. As FPGAs are used in many different applications, it does not make sense to include TCAM blocks inside them as they would be used only in a small fraction of the systems. Therefore, TCAMs are emulated using the logic resources available inside the FPGA. In recent years, a number of schemes to emulate TCAMs on FPGAs have been proposed, some of them based on the use of the logic resources and others on the use of the embedded memory blocks available on the FPGA. In this brief, a technique to efficiently emulate TCAMs on Xilinx FPGAs is presented. The proposed scheme is based on the use of lookup tables (LUTs) and partial reconfiguration to achieve a more effective use of the FPGA resources while supporting the addition and removal of rules. The proposed scheme has been compared to existing implementations and the results show that it can achieve significant savings in resource usage. In addition, it enables the use of all the LUTs in the device for TCAM implementation, something that is not supported by existing approaches that use LUTRAMs.

An Error-Detection and Self-Repairing Method for Dynamically and Partially Reconfigurable Systems

Abstract: Reconfigurable systems are gaining an increasing interest in the domain of safety-critical applications, for example in the space and avionic domains. In fact, the capability of reconfiguring the system during run-time execution and the high computational power of modern Field Programmable Gate Arrays (FPGAs) make these devices suitable for intensive data processing tasks. Moreover, such systems must also guarantee the abilities of self-awareness, self-diagnosis and self-repair in order to cope with errors due to the harsh conditions typically existing in some environments. In this paper we propose a self-repairing method for partially and dynamically reconfigurable systems applied at a fine-grain granularity level. Our method is able to detect correct and recover errors using the run-time capabilities offered by modern SRAM-based FPGAs. Fault injection campaigns have been executed on a dynamically reconfigurable system embedding a number of benchmark circuits. Experimental results demonstrate that our method achieves full detection of single and multiple errors, while significantly improving the system availability with respect to traditional error detection and correction methods.

Theory and practice of error control codes

Abstract: algorithmics and modular computations, Theory of Codes and Cryptography (3).From an analytical 1. RE Blahut. Theory and practice of error control codes. eecs.uottawa.ca/∼yongacog/courses/coding/ (3) R.E. Blahut,Theory and Practice of Error Control Codes, Addison Wesley, 1983. QA 268. Cached. Download as a PDF 457, Theory and Practice of Error Control CodesBlahut 1984 (Show Context). Citation Context..ontinued fractions.

Structure Regulator for the Perturbations Attenuation in a Quadrotor

Abstract: In this work, we study the structure regulator for the perturbations attenuation which is based on the infinite structure regulator. The structure regulator is able to attenuate the perturbations if the transfer function of the departures and perturbations has a numerical value almost equal to zero, and it does not require the perturbations to attenuate them. We apply the structure regulator and the infinite structure regulator to a quadrotor which maintains the horizontal position with respect to the earth for the step and sine perturbations.

High-Performance and Energy-Efficient CNFET-Based Designs for Ternary Logic Circuits

Abstract: Recently, the demand for portable electronics and embedded systems has increased. These devices need low-power circuit designs because they depend on batteries as an energy resource. Moreover, multi-valued logic (MVL) circuits provide notable improvements over binary circuits in terms of interconnect complexity, chip area, propagation delay, and energy consumption. Therefore, this paper proposes new ternary circuits aiming to lower the power delay product (PDP) to save battery consumption. The proposed designs include new ternary gates [standard ternary inverter (STI) and ternary NAND (TNAND)] and combinational circuits [ternary decoder (TDecoder), ternary half-adder (THA), and ternary multiplier (TMUL)] using carbon nano-tube field-effect transistors (CNFETs). This paper employs the best trade-off between reducing the number of used transistors, utilizing energy-efficient transistor arrangement such as transmission gate, and applying the dual supply voltages (V dd and V dd /2). The five proposed designs are compared with the latest 15 ternary circuits using the HSPICE simulator for different supply voltages, different temperatures, and different frequencies; 180 simulations are performed to prove the efficiency of the proposed designs. The results show the advantage of the proposed designs in reduction over 43% in terms of transistors' count for the ternary decoder and over 88%, 99%, 98%, 86%, and 78% in energy consumption (PDP) for the STI, TNAND, TDecoder, THA, and TMUL, respectively.

Application of Fractional Order Sliding Mode Control for Speed Control of Permanent Magnet Synchronous Motor

Abstract: This paper investigates speed regulation of permanent magnet synchronous motor (PMSM) system based on sliding mode control (SMC). Sliding mode control has been vastly applied for speed control of PMSM. However, continuous SMC enhancement studies are executed to improve the performance of conventional SMC in terms of tracking and disturbance rejection properties as well as to reduce chattering effects. By introducing fractional calculus in the sliding mode manifold, a novel fractional order sliding mode controller is proposed for the speed loop. The proposed fractional order sliding mode speed controller is designed with a sliding surface that consists of both fractional differentiation and integration. Stability of the proposed controller is proved using Lyapunov stability theorem. The simulation and experimental results show the superiorities of the proposed method in terms of faster convergence, better tracking precision and better anti-disturbance rejection properties. In addition, chattering effect of this enhanced SMC is smaller compared to those of conventional SMC. Last but not least, a comprehensive comparison table summarizes key performance indexes of the proposed controller with respect to conventional integer order controller.