Sharif Digital Repository

The present study provides an accurate simulation of velocity and temperature distributions of inhalation thermal injury in a human upper airway, including vestibule, nasal cavity, paranasal sinuses, nasopharynx, oropharynx, larynx, and upper part of main bronchus. To this end, a series of CT scan images, taken from an adult woman, was used to construct a three dimensional model. The airway walls temperature was adjusted according to existing in vivo temperature measurements. Also, in order to cover all breathing activities, five different breathing flow rates (10, 15, 20, 30, and 40. l/min) and different ambient air temperatures (100, 200, 300, 400, and 500. °C) were studied. Different flow... 

Surface tension driven passive micro-pumping relies mainly on the surface tension properties. To have control over surface tension driven passive micro-pumps (STD-PMPs), it is essential to understand the physical background of the fluid flow in these pumps. Hence, the purpose of this work is to give an exploration of the flow physics of a STD-PMP. In this regard, computer simulation is used to give detailed information about the flow pattern and physical phenomena at different conditions. To this end, a droplet of water, with a specified diameter, is placed onto an entry port connected to another droplet at the exit port via a microchannel. The results indicate that the pumping process, in... 

Long term evolution (LTE)-advanced aims the peak data rates in excess of 3 Gbps for the next generation wireless communication systems. Turbo codes, the specified channel coding scheme in LTE, suffers from a low-decoding throughput due to its iterative decoding algorithm. One efficient approach to achieve a promising throughput is to use multiple Maximum a Posteriori (MAP) cores in parallel, resulting in a large area overhead, a big drawback. The scaled Max-log MAP algorithm is a common approach to implement the MAP algorithm due to its efficient architecture with its acceptable performance. Although many works have been reported to reduce the area of the MAP unit, an efficient VLSI... 

Long-term evolution (LTE) is aimed to achieve the peak data rates in excess of 300 Mb/s for the next-generation wireless communication systems. Turbo codes, the specified channel-coding scheme in LTE, suffer from a low-decoding throughput due to its iterative decoding algorithm. One efficient approach to achieve a promising throughput is to use multiple maximum a posteriori (MAP) cores in parallel, resulting in a large area overhead. The two computationally challenging units in an MAP core are α and β recursion units. Although several methods have been proposed to shorten the critical path of these recursion units, their area-efficient architecture with minimum silicon area is still missing.... 

5-th generation mobile networks aim the peak data rates in excess of few Gbs, which may appear to be challenging to achieve due to the existence of some blocks such as the turbo decoder. In fact, the interleaver is known to be a major challenging part of the turbo decoder due to its need to the parallel interleaved memory access. LTE uses Quadratic Permutation Polynomial (QPP) interleaver, which makes it suitable for the parallel decoding. In this paper, a new property of the QPP interleaver, called the correlated shifting property, is theoretically proved, leading to a fully scalable interleaver and a low-complexity address generator for an arbitrary order of parallelism. The proposed... 

Processor allocation in todays many core MPSoCs is a challenging task, especially since the order and requirements of incoming applications are unknown during design stage. To improve network performance, balance the workload across processing cores, or mitigate the effect of hot processing elements in thermal management methodologies, task migration is a method which has attracted much attention in recent years. Runtime task migration was first proposed in multicomputer with load balancing as the major objective. However, specific NoC properties such as limited amount of communication buffers, more sensitivity to implementation complexity, and tight latency and power consumption constraints... 

Processor allocation in todays many core MPSoCs is a challenging task, especially since the order and requirements of incoming applications are unknown during design stage. To improve network performance, balance the workload across processing cores, or mitigate the effect of hot processing elements in thermal management methodologies, task migration is a method which has attracted much attention in recent years. Runtime task migration was first proposed in multicomputer with load balancing as the major objective. However, specific NoC properties such as limited amount of communication buffers, more sensitivity to implementation complexity, and tight latency and power consumption constraints... 

A structure is suggested for spasing. The presented surface plasmon amplification by stimulated emission of Radiation (SPASER) is made up of a graphene nanosphere, which supports localized surface plasmon modes, and a quantum dot array, acting as a gain medium. The gain medium is pumped by an external light source. Since all the plasmons are carried on a graphene platform, the structure features coherent surface plasmons with high confinement and large life time. All the structures are analyzed theoretically using full quantum mechanical description. The main advantage of the proposed SPASER is its simple tuning capability of changing graphene's Fermi level, which is performed by either... 

The rate constants of the oxidation of CO on a number of pure and La 2O3 doped NiO/Al2O3 solid catalysts were correlated with the mole percent of dopant, calcinations temperature, surface area, pore volume and pore mouth diameter by an artificial neural network simulator. The cross validation method had to be used due to the scarcity of the data. A three-layer network with 3 nodes in the hidden layer was found to simulate the system well. © Akadémiai Kiadó, Budapest. All rights reserved  

This paper addresses the microstructure and tensile-shear mechanical performance of MS1200 Giga-grade martensitic advanced high strength steel resistance spot welds. The key phase transformations in MS1200 welds were lath martensite formation in the fusion zone (FZ) and upper-critical heat affected zone (HAZ), new ferrite formation in the inter-critical HAZ and martensite tempering in the sub-critical HAZ. The MS1200 welds were featured by a near matching hardness in the fusion zone and under-matching hardness in the heat affected zone (HAZ) compared to the base metal. At certain process window a complete nugget pullout and separation was observed with high post-necking tearing energy. The... 

Direct yaw moment control (DYMC) is one of the most effective method that improves not only the directional stability of the vehicles but also their road handling and controllability to a great extent. In this method by developing a difference in the longitudinal force (often the braking force) on two sides of the vehicle, an external stabilizing yaw moment is applied to the vehicle. In this study, an optimal control law for DYMC is proposed. The control law is based on the yaw rate, the lateral velocity feedback, and the steering angle feedforward. Simulation results obtained indicate that considerable improvement in the vehicle dynamic behavior can be achieved when the optimal yaw moment...