Sharif Digital Repository

A dual-mode power and performance optimized SRAM is presented. Given the fact that the power and speed associated with the cell access time are directly related to the sense amplifier offset a new optimization platform based on the hybrid offset-cancelled current sense amplifier (OCCSA) [1] is presented. It is shown that the speed and power overhead of the offset cancellation can be optimized in a multi-variable auto-calibration loop to achieve the lowest power or the highest performance mode. The flexibility of having two degrees of freedom in OCCSA offers a significant bitline delay reduction with minimum power sacrifice in the high performance mode. The proposed scheme is verified using a... 

The manner of organizing the sensors in the wireless sensor network for increasing the capability and optimized using of the sensors is of great importance. Hence considering coverage parameter in every Wireless Sensor Network (WSN) is extremely essential and critical. The matter of overlapping covered area by sensors in 2D space had been considered until now. This paper is suggested a pattern in which no more are the sensors located at the same surface, but using the 3D geometrical figures like cube, pyramid and etc, in which the sensors were spreading about the different surfaces. Locating the sensors on the different surfaces can be useful under conditions where the space is not in same... 

the application of current sense amplifiers in scaled SRAM design is limited by two factors: the DC offset due to the device mismatch and limited voltage headroom. The presented scheme reduces the effect of offset by proposing an extra phase for offset cancellation before current sensing takes place. A twofold reduction of the cell access time is achieved compared to the conventional scheme under similar cell current and bitline capacitance. The offset cancellation phase takes place in parallel to the wordline decoding time in order to speed up the current sensing. The proposed scheme requires a small power budget due to a self shut off mechanism. In addition to presenting a comparison with... 

Wireless sensor networks (WSNs) are composed of hundreds or thousands of small nodes, which work together and associate with a specific task or tasks to do. It is expected that wireless sensor networks will be used widely in many applications in the near future. One of the most important issues in WSNs is localisation. There are crucial problems over network localisation such as security attacks (internal or external), energy efficiency, and accuracy, which impact performance and energy-consuming of wireless sensor networks. The main source of these problems is network topology. A long-thin network topology (LTNT) in wireless sensor can produce errors in network localisation due to special... 

Over the past few years, visual prostheses (namely, Argus II retinal implant) and gene therapy have obtained FDA approval in treating blindness resulting from retinitis pigmentosa. Compared to gene therapy; Argus II is less costly with a demonstrated favorable outcome, though the vision is yet artificial. To obtain better results, expectation counseling and preoperative retinal assessment are critical. The global experience with Argus II has enrolled no more than 300 cases so far. The first Argus II retinal prosthesis in Iran was successfully implanted in Shiraz (October 2017). To date, Argus II artificial retina is implanted in four patients in Iran. Beside successful surgery and...