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        1 - An efficient Imprecise 4:2 Compressor Using Gate Diffusion Input Supplemented with Dynamic Threshold
        Forouzan Bahrami Nabiollah Shiri Farshad Pesaran
        Approximate computing is a new design concept that causes a trade-off between circuitry performance and accuracy. The approximate circuits are more useful in error-resilient applications, like image processing. This paper introduces a new imprecise 4:2 compressor with 1 More
        Approximate computing is a new design concept that causes a trade-off between circuitry performance and accuracy. The approximate circuits are more useful in error-resilient applications, like image processing. This paper introduces a new imprecise 4:2 compressor with 12 transistors. The presented compressor exhibits low power consumption and provides full-swing outputs, due to the utilization of gate diffusion input and dynamic threshold techniques. The implementation of this compressor using a 16 nm carbon nanotube field-effect transistor (CNTFET) technology yields a minimum area. According to the simulation results, the suggested imprecise 4:2 compressor shows a significant reduction in power consumption and power-delay-product (PDP) compared to the precise 4:2 compressor, with a reduction of 95.18% and 95.27%, respectively. Also, the compressor is evaluated regarding the approximate figure of merits like error rate, mean error distance, and normalized mean error distance. The simulation results affirm the priority of the suggested circuit, especially in digital signal processing. Manuscript profile
      • Open Access Article

        2 - Low-power and reliable approximate subtractors for image processing applications
        Fatemeh Pooladi Farshad Pesaran Nabiollah Shiri
        In this paper, two new approximate subtractors are presented. The proposed circuits are implemented based on gate diffusion input (GDI) and dynamic threshold (DT) techniques and are named Proposed-1 and Proposed-2. The Proposed-1 subtractor has 10 transistors, while Pro More
        In this paper, two new approximate subtractors are presented. The proposed circuits are implemented based on gate diffusion input (GDI) and dynamic threshold (DT) techniques and are named Proposed-1 and Proposed-2. The Proposed-1 subtractor has 10 transistors, while Proposed-2 has 12 transistors. Subtractors are implemented by 32 nm carbon nanotube field effect transistor (CNTFET) technology. Various studies have been performed and show the high efficiency and performance of the circuits in different conditions without reducing their output voltage, which is caused by the use of DT in their implementation. The proposed circuits use XOR and NOT gates, both of which have 4 out of 8 error states. The presented subtractors can be implemented in an unsigned non-recovery divider with different structures including vertical, horizontal, square and triangular, etc., and finally, they can be used in image processing applications to detect the difference between two images, either medical or standard images. The simulation results show the better performance of the proposed circuits, Proposed-1 and Proposed-2 save PDP of 88.36% and 83.25%, respectively. Manuscript profile