Sharif Digital Repository

The importance of hyperthermia as a promising method in disruption and removal of cancerous cells is well understood. One of the effective options of concentration of heat within a specific tissue is using laser and exploiting absorption properties of metallic nanostructures. In this report, the geometrical effect of gold nanostructures in the performance of laser based hyperthermia has been analyzed. The analysis is based on the consideration of absorption properties of gold nanostructures, interaction of laser light with a specific tissue containing nanostructures and the effect of generated heat on elevation of temperature inside the tissue. The analysis is performed using Mie theory (for... 

This paper describes a vector quantization of a 600 bps speech coding parameters based on the Mixed Excitation Linear Prediction (MELP) model, which was accepted as a standard in communication on narrow-band HF channels. The MELP speech coders are robust in difficult background noise environments and intended mostly for military communications. To reduce the bit rate, a joint vector quantization of multi-frame is developed that takes advantage of inherent inter-frame redundancy of the MELP parameters. By grouping parameters of 4 frames into a multi-frame and using vector quantization, bit rate is decreased 4 times and output speech is still intelligible  

In this paper, we propose a packet-switched network-on-chip (NoC) architecture which can provide a number of low-power, low-latency virtual point-to-point connections for communication flows. The work aims to improve the power and performance metrics of packet-switched NoC architectures and benefits from the power and resource utilization advantages of NoCs and superior communication performance of point-to-point dedicated links. The virtual point-to-point connections are set up by bypassing the entire router pipeline stages of the intermediate nodes. This work addresses constructing the virtual point-to-point connections at run-time using a light-weight setup network. It involves monitoring... 

In recent years, enterprise Solid-State Drives (SSDs) are used in the caching layer of high-performance servers to close the growing performance gap between processing units and storage subsystem. SSD-based I/O caching is typically not effective in workloads with burst accesses in which the caching layer itself becomes the performance bottleneck because of the large number of accesses. Existing I/O cache architectures mainly focus on maximizing the cache hit ratio while they neglect the average queue time of accesses. Previous studies suggested bypassing the cache when burst accesses are identified. These schemes, however, are not applicable to a general cache configuration and also result... 

This paper is related to the studies taken place during last decade to understand the intact behavior of a Collapsible Loess subjected to loading and wetting at Advanced Soil Mechanics Laboratory of Sharif University of Technology, Tehran, Iran. In this regard intact block samples are carefully taken from Hezar Pich Hill in the city of Gorgan, Iran, and various tests are performed on undisturbed specimens recovered from the intact block samples. In this way three automated unsaturated oedometer are built and a conventional triaxial apparatus is upgraded to a fully automated unsaturated triaxial device to accommodate rigorous and different stress and wetting path with continuous data... 

Computed tomography (CT) simulators are versatile tools for scanning protocol evaluation, optimization of geometrical design parameters, assessment of image reconstruction algorithms, and evaluation of the impact of future innovations attempting to improve the performance of CT scanners. Computational human phantoms (CHPs) play a key role in simulators for the radiation dosimetry and assessment of image quality tasks in the medical x-ray systems. Since the construction of patient-specific CHPs can be both difficult and time-consuming, nominal standard/reference CHPs have been established, yielding significant discrepancies in the special design and optimization demands of patient dose and... 

Detecting emotions directly from a speech signal plays an important role in effective human-computer interactions. Existing speech emotion recognition models require massive computational and storage resources, making them hard to implement concurrently with other machine-interactive tasks in embedded systems. In this paper, we propose an efficient and lightweight fully convolutional neural network for speech emotion recognition in systems with limited hardware resources. In the proposed FCNN model, various feature maps are extracted via three parallel paths with different filter sizes. This helps deep convolution blocks to extract high-level features, while ensuring sufficient separability.... 

Continuous down scaling of CMOS technology in recent years has resulted in exponential increase in static power consumption which acts as a power wall for further transistor integration. One promising approach to throttle the substantial static power of Field-Programmable Gate Array (FPGAs) is to power off unused routing resources such as switch boxes, known as dark silicon. In this paper, we present a Power gating Switch Box Architecture (PESA) for routing network of SRAM-based FPGAs to overcome the obstacle for further device integration. In the proposed architecture, by exploring various patterns of used multiplexers in switch boxes, we employ a configurable controller to turn off unused... 

Hydro collapsible soils are of kinds of problematic soils which show high shear strength at low degrees of saturation but due to wetting, their Meta stable structure collapses and will be subjected to large deformation. In this study by applying isotropic triaxial loadings to undisturbed samples, mechanical behavior of a highly collapsible loessial soil has been assessed. During tests, matric suction of the samples was controlled as well as the mean net stress, and the variation of the degree of saturation was monitored continuously. Two types of stress paths were conducted on the samples namely "Isotropic induced collapse" under applying constant matric suctions and "wetting induced... 

Sensor networks usually generate mass of data, which if not structured for future applications, will require much effort on analytical processing and interpretations. Thus, storing sensor data in an effective and structured format is a key issue in the area of sensor networks. In the meantime, even a little improvement on data storing structure may lead to a significant effect on the lifetime and performance of the sensor network. This paper describes a new method for sensor storage that combines semantic web concepts, a data aggregation method along with aligning sensors in hierarchical form. This solution is able to reduce the amount of data stored at the sink nodes significantly. At the... 

Hybrid Multi-Level Cache Architectures (HCAs) are promising solutions for the growing need of high-performance and cost-efficient data storage systems. HCAs employ a high endurable memory as the first-level cache and a Solid-State Drive (SSD) as the second-level cache. Spin-Transfer Torque Magnetic RAM (STT-MRAM) is one of the most promising candidates for the first-level cache of HCAs because of its high endurance and DRAM-comparable performance along with non-volatility. However, STT-MRAM faces with three major reliability challenges named Read Disturbance, Write Failure, and Retention Failure. To provide a reliable HCA, the reliability challenges of STT-MRAM should be carefully addressed....