Sharif Digital Repository

The reliable transfer in Network on Chips (NoCs) can be threatened by crosstalk fault occurring in wires. Crossstalk fault is due to inter-wire coupling capacitance that based on the patterns of transitions appearing on the wires, significantly limits the reliability of NoCs. Among these transitions, 101 and 010 bit patterns impose the worst crosstalk effects to wires. This work intends to increase the reliability of NoCs against crosstalk faults by applying an improved Fibonacci-based numeral system, called Doubled-Penultimate Fibonacci (DP-Fibo). In the DP-Fibo coding algorithm, code words without ‘101’ and ‘010’ bit patterns are produced to reduce crosstalk faults. Experimental results... 

This paper proposes some bounds on maximum of magnitude of a random mask in Fourier domain. The random mask is used in random sampling scheme. Having a bound on the maximum value of a random mask in Fourier domain is very useful for some iterative recovery methods that use thresholding operator. In this paper, we propose some different bounds and compare them with the empirical examples. © 2017 IEEE  

In this paper, we propose an Adaptive Singular Value Thresholding (ASVT) for low rank recovery under affine constraints. Unlike previous iterative methods that the threshold level is independent of the iteration number, in our proposed method, the threshold in adaptively decreases during iterations. The simulation results reveal that we get better performance with this thresholding strategy. © 2017 IEEE  

The aim of this study is to determine the determine effects of magnesium supplementation on anthropometric indices Consist of body weight (BW), waist circumference (WC), body mass index (BMI) and body fat percentage (BF%). In this systematic review and dose-response meta-analysis, we searched PubMed, Cochrane Library, Scopus, Web of Science and Google Scholar from databases inception up February 2020 for relevant randomized controlled trials. Quality of evidence was evaluated using the Cochrane Collaboration Tool. All of outcome in this meta-analysis were pooled using Random Effect Model. Analysis of dose-response for magnesium dosage was carried out using a fractional polynomial model. The... 

Abstract The aim of this study was to determine the effects of Mg supplementation on anthropometric indices consisting of body weight, waist circumference (WC), BMI and body fat percentage. In this systematic review and dose-response meta-analysis, we searched PubMed, Cochrane Library, Scopus, Web of Science and Google Scholar from databases inception up to February 2020 for relevant randomised controlled trials. Quality of evidence was evaluated using the Cochrane Collaboration Tool. All the outcomes of this meta-analysis were pooled using the random effect model. Analysis of dose-response for Mg dosage was carried out using a fractional polynomial model. The systematic review and... 

In this study, the effect of agglomeration and non-uniform dispersion of silica particles on the mechanical and microstructural properties of cement paste incorporating silica fume and nanosilica (NS) with various specific surface areas (SSA) is experimentally investigated. The SSA and replacement percent of silica particles were considered as test variables and four series of mixes were made including one set of mixes for silica fume with a SSA of 20 m2/g and three sets of mixes for three different types of NS with SSA equal to 90, 200 and 380 m2/g. In each series of mix designs three different cement replacement percents of 1.5%, 3% and 5% were applied. The results indicate that as the SSA... 

So far, the need for power systems to be control automated has been approached. Moreover, the advent of smart technological infrastructures calls for a more systematic and well-designed schemes for data acquisition process. Hence, Remote Terminal Units (RTUs) are going to be considered as a crucial part of smart grid puzzle in power distribution systems. This paper aims to present a novel practical approach to have the RTU placement dilemma unraveled in power distribution systems. Practically approaching in this paper, some pragmatic factors of major importance in this respect are introduced. A framework with which the utility's experts' knowledge could be efficiently exploited is presented... 

To extend a procedure to ensure the safe operation of a water reactor, we develop a numerical method to compute the high frequency pressure spikes of water hammer with liquid column separation in pipes. In this regard, we first extend a finite-volume all-speed method to solve the full one-dimensional Navier-Stokes equations. This method is capable of simulating gas and liquid phases as well as the vapor-liquid one. On the other hand, the current extended method should be capable of capturing high frequency pressure spikes, which are formed due to water hammer and column separation in pipes. The existence of such high frequency spikes has been recently reported experimentally by other... 

Multicomputers have experienced a rapid development during the last decade. Multicomputers rely on an interconnection network among processors to support the message-passing mechanism. Therefore, the reliability of the interconnection network is very important for the reliability of the whole system. In this paper a new fault-tolerant routing algorithm, which is based on dimension order routing, is proposed for k-ary 2-cubes. Packets are sent to their destination through XY routing algorithm and if this transmission is not possible, YX routing algorithm is applied. The XY routing algorithm nullifies offset in "X" direction before routing in "Y" direction, but the YX routing algorithm first... 

SiC Ceramic was joined to itself using active brazing alloys, like Ti in shape of sheet filler of Ag-cu and Ti-6AI-4V. This operation occurred in an inert gas furnace. Interfacial microstructure was studied with scanning electron microscopy and X-Ray diffraction. Variation of Electrical Specific Resistance measured by 4 pin astute multimeter and strength of these joints was measured by fracture shear loading. This joint happened at 900°C and upper temperature with 90 minutes and upper time. Electrical specific resistance goes up with the joint in low temperature and time but this variation is very little. The microstructure showed excellent bonding at the interfaces. The data showed also... 

The main scope of this study is to analyse muscle-driven forward dynamics simulation of stair locomotion to understand the functional differences of individual muscles during the movement. A static optimization was employed to minimize a performance criterion based on the muscle energy consumption to resolve muscle redundancy during forward dynamics simulation. The proposed method was employed to simulate a musculoskeletal system with ten degrees of freedom in the sagittal plane and containing 18 Hill-type musculotendon actuators per leg. Simulation results illustrated that simulated joint kinematics closely tracked experimental quantities with root-mean-squared errors less than 1°. In... 

In this study, zirconia antistatic coatings were synthesized by a simple dip coating sol-gel route on glass substrates, then applied to polymer-based composites to potentially improve their dust or water repellent capabilities. The coating solution contained a precursor (ZrCl4), solvent (isopropanol) and coupling agent. FTIR spectra confirmed ZrO2 and ZrO compounds in both solution and antistatic coating. FE-SEM images indicated ZrO2 fibers’ thickness was controlled by changing ZrCl4 concentration (150 g–15 g ZrCl4/l) or relative humidity (20%–60%) during coating drying. Fibers grew thicker when decreasing the former or increasing the latter. The surface electrical resistivity for all... 

A vector bond graph approach for dynamic modeling of human musculo-skeletal system is addressed in this article. In the proposed model, human body is modeled as a ten-segment, nine degree of freedom, mechanical linkage, actuated by ten muscles in sagittal plane. The head, arm and torso (HAT) are modeled as a single rigid body. Interaction of the feet with the ground is modeled using a spring-damper unit placed under the sole of each foot. The path of each muscle is represented by a straight line. Each actuator is modeled as a three-element, Hill-type muscle in series with tendon. The governing equations of motion generated by the proposed method are equivalent to those developed with more... 

We present in this paper a new method of modifying hard-core potentials to correctly predict the equilibrium and non-equilibrium properties of real fluids at low densities (specifically when ρ ≤ B/C where ρ is density, and B and C are the second and third virial coefficients) only by one set of potential parameters. Because the molecular diameter becomes smaller when temperature increases, we introduced a new expression for the variation of molecular diameter with temperature that incorporates this effect. The temperature dependence of the diameter was used in both Sutherland (ST) and square-well (SW) potential models to modify the second virial coefficient. Then we have shown that the... 

Integrating humans and robotics technology into one system offers multiple opportunities for creating assistive technologies that can be employed in biomechanical, industrial, and aerospace applications. The present study deals with employing the adaptive neuro-fuzzy inference system (ANFIS) approach in rule base derivation for powered exoskeleton intelligent control to assist paraplegic patient mobility. By employing the hybrid learning algorithm, optimal distributed membership functions to describe the mapping relation in the input and output parameters of the gait cycle were derived. As the proposed control strategy was unaffected by changing human dynamics, the reliability and robustness... 

In this paper conception and dynamic modeling of a snake-like robot with passive wheels and compliant joints is investigated. The proposed robot has the ability to follow a socalled Serpenoid curve passively by using an appropriate set of initial conditions. Introduction of a unique structure at each joint enables the robot to achieve passive motion. A torsional spring is used in series with an actuator between each two consecutive links. Using wheels at the middle of each link imposes many non-holonomic constraints to the system. These constraints reduce the degrees of freedom of the system to only two. Due to the existence of these non-holonomic constraints, dynamic equations governing the... 

Chitosan was modified with polyacrylonitrile (PAN) through ceric-initiated graft copolymerization. The chitosan-g-PAN product was saponified using sodium hydroxide aqueous solution to prepare a novel superabsorbent hydrogel, H-chitoPAN. Duration of completing the saponification reaction as well as the water absorbency capacity of the hydrogel was decreased with increasing the alkaline concentration. Either chitosan-g-PAN or H-chitoPAN was characterized by FTIR spectroscopy and DSC, TGA, and DTG thermal methods. According to FTIR, all the nitrile groups were converted to carboxylate and carboxamide groups. Both modified chitosans exhibited enhanced thermal stability over chitosan. The... 

An approach to access azaborininones (carbonyl-containing, boron-based heterocyclic scaffolds) using simple reagents and conditions from both organotrifluoroborates and boronic acids is described. An inexpensive, common reagent, SiO2, was found to serve as both a fluorophile and desiccant to facilitate the annulation process across three different azaborininone platforms. Computational analysis of some of the cores synthesized in this study was undertaken to compare the azaborininones with the analogous carbon-based heterocyclic systems. Computationally derived pKa values, NICS aromaticity calculations, and electrostatic potential surfaces revealed a unique isoelectronic/isostructural... 

In this paper, the ball valve performance is numerically simulated using an unstructured CFD (Computational Fluid Dynamics) code based on the finite volume method. Navier-Stokes equations in addition to a transport equation for the vapor volume fraction were coupled in the RANS solver. Separation is modeled very well with a modification of turbulent viscosity. The results of CFD calculations of flow through a ball valve, based on the concept of experimental data, are described and analyzed. Comparison of the flow pattern at several opening angles is investigated. Pressure drop behind the ball valve and formation of the vortex flow downstream the valve section are also discussed. As the... 

We use the direct simulation Monte Carlo (DSMC) method and investigate the subsonic rarefied gas flow through micro/nanochannels, imposing a constant pressure ratio and a constant temperature difference between the inflow and wall temperature. We further study the heat transfer characteristics of subsonic nitrogen gas flow under this imposed temperature difference. We show that, specifying a higher temperature magnitude would lead to more rarefactions even imposing a fixed temperature difference. This consequently results in a higher wall heat flux rate for a fixed inflow-wall temperature difference. Our investigating shows that the number of simulated particles need to increase suitably if...