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hajsadeghi--khosrow
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Density and Level Monitoring and Control in Polypropylene Plants
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor)
Abstract
Polypropylene plants receive propylene monomer and produce polypropylene polymer by inducing chemical reactions under high pressure and high temperature conditions. In these plants it is essential to monitor and carefully control the density and level of the material contents in slurry high pressure and high temperature reactors and vessels. Due to process conditions and the advantages of the non contact measuring method we use radioactive level and density measurement method specially gamma ray level and density detectors and transmitters in P.P plants. Sometimes, however known and unknown natural or manmade factors may affect the performance of these devices. The known factors such as NORM...
10-Bit 500-MS/s Pipelined Analog to Digital Converter
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor)
Abstract
High speed data converters are very often used in telecommunication systems. Since these systems are increasingly used in mobile form reducing the power consumption in these circuits is of great importance. The goal of this project was to design a pipeline 10 bit converter for a sample rate of 500 M sample/s with a power consumption of 50mW for the input level of 1Vp-p and a 1.5V power supply in 0.18μm CMOS technology. To reach these goals a number of low-power techniques are proposed in various levels of abstraction. In system level, the sampling and feedback capacitors, as well as the stage resolution of the ADC is optimized .And to...
The Application of Ultrasonic Waves for Determining the Liquid Level in Reactor for Monitoring a Process Reactor
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor)
Abstract
In this research non-contact ultrasonic based method is used for liquid level measurement in a container. A system has been designed and developed to determine the liquid level and show the results on a personal computer. The system contains three main parts, which are mechanical and electronic parts and the programming. The setup can measure the liquid level with the accuracy of 1cm. An ATMEGA8 microprocessor commands to relays and controls the pumps. The pumps are used to change the height of the liquid in the containers to accurately calibrate the sensor and test its operation. The ultrasonic sensor, which is mounted above the vessel, transfers the data to an ATMEGA64 microprocessor for...
Speckle Noise Reduction Using Adaptive Filters with Application to SAR Images
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor)
Abstract
SAR image noise is a significant problem for SAR image analysis.The inherent noise of SAR images, known as speckle, seriously affects the SAR image interpretation. It also has adverse effects on the classification and segmentation of SAR images. Due to its great significance, the SAR image processing has received considerable attention in recent years and many researchers have developed techniques to reduce the inherent noise accompanying the SAR images. A survey of the literature shows that the wavelet analysis is one of the most common methods used for speckle reduction. While the power of the morphological analysis method has mostly not been recognized, we have utilized this efficient...
Design Low Power Carry Skip Adder with Gate Diffusion Input Technique
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor)
Abstract
The purpose of this thesis is designing and implementation of a Carry Skip Adder using CMOS traditional technology and Gate Diffusion Input technique (GDI). I present a carry skip adder (CSKA) structure that has a higher speed, lower energy consumption compared with the conventional one. The Gate Diffusion Input is a novel technique for low power digital circuit design. This technique reduces the power dissipation, propagation delay, area of digital circuits and it maintains low complexity of logic design
Time to Digital Converters for ADPLL Applications
, Ph.D. Dissertation Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor)
Abstract
Effect of resolution of Time to Digital Converters (TDCs) on the performance of All-Digital Phase Locked Loops (ADPLLs) and capability of achieving higher resolution in advanced technologies lead to introducing different kinds of TDCs. Beside the analysis of different kinds of TDCs, This thesis proposes three new TDCs based on the time amplifi-cation concept. A new pipeline TDC is designed using a wide dynamic range time amplifi-er. A new method is used to widen dynamic range of the conventional time amplifiers. In order to get a low power high resolution conversion, a new delay element design is devel-oped to reduce the delay value and its sensitivity to mismatch and process variations....
Low power Clock and Data Recovery Circuits in 20Gb/s Range in CMOS Technology
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor)
Abstract
Growing demand for increased data transmission in communication systems and the internet, has intensified the need to increase the bandwidth of high speed transceivers. One of the main elements in high speed receivers is the clock and data recovery circuit which guarantees the transfer of data with high reliability. In this thesis, the design of a clock and data recovery circuit for high frequency applications is considered. The aim of this project is the design of a circuit with low power and low jitter for high-speed input data. A new four stage LC ring oscillator is designed that works at the quarter rate of the input. A new idea for the design of the binary phase detectors has also been...
Design of Clock and Data Recovery Circuits Inmulti Gb/s Range in CMOS Technology
, M.Sc. Thesis Sharif University of Technology ; HajSadeghi, Khosrow (Supervisor)
Abstract
Some applications need fast locking clock and data recovery circuits for example the circuits that operate in burst mode must lock to the data packets which are transmitting from different transmitters very quickly and in just a few bit times. In such applications open-loop clock and data recovery circuits are used because lock time in closed-loop clock and data recovery circuits is usually much longer.
In this thesis a new open loop clock and data recovery circuit based on injection locking method has been proposed. This circuit can be used in applications such as passive optical networks that need fast locking. In this architecture a super harmonic injection-locked frequency divider...
In this thesis a new open loop clock and data recovery circuit based on injection locking method has been proposed. This circuit can be used in applications such as passive optical networks that need fast locking. In this architecture a super harmonic injection-locked frequency divider...
A 12 Bit Delta-Sigma Modulator For Wireless Applications
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor)
Abstract
Analog to digital converters are one of the most important component of Bluetooth and GSM receivers. The pipeline and Successive Approximation Register (SAR) ADCs are mainly used in these receivers. However, the pipeline ADCs consume lots of power and SAR ADCs suffer the resolution in advanced technologies. On the other hand, the Delta-Sigma ADCs are capable of achieving high resolution with a low power. So in this thesis, the various kinds and different implementations of Delta-Sigma Modulators are introduced. The system level design and the conversion between Discrete-Time Modulators and Continuous-Time Modulators are explained. The non-ideality effects such as limited gain and bandwidth...
Evaluation of Implementing Machine Learning Methods on Multi-Access Edge Computing Based Networks, Focusing on Computation Offloading
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor)
Abstract
Many applications that require heavy processing, such as augmented reality, facial recognition, self-driving cars, and digital healthcare systems, are emerging. Many devices in the Internet of Things space cannot process such a volume of calculations. One of the newest methods to solve this problem is using new architectures in network design, among which we can refer to the edge computing architecture. In this method, by offloading the computation on the available computing resources close to the network's end nodes, we try to provide the results of the calculations for the end nodes of the network as quickly as possible. In this thesis, the problem of determining the computation offloading...
Predicting Research Trends by Using Link Prediction in Keywords Network
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor) ; Kavousi, Kaveh (Co-Advisor)
Abstract
The rapid development of scientific areas in this modern era makes the process of finding new field of research slow and laborious for prospective scholars. Thus, having a vision of the future could be helpful to pick a right path for doing researches and ensuring that it is worth to invest in. This thesis seeks to predict research trends by using link prediction approaches on keywords network and discusses about the performance of various algorithms in different situations. Moreover, for the last part of the experiments, novel link prediction algorithms are proposed by the author, enhances the accuracy of prediction results. The data set collected from Sciencedirect and Scopus by a strong...
Forecasting Science Hotspots Based on Keywords Network
, M.Sc. Thesis Sharif University of Technology ; Hajsadeghi, Khosrow (Supervisor) ; Khosravi, Kaveh (Supervisor)
Abstract
When the keywords in academic articles are collected and accumulated to achieve a certain amount, they will display a network property. This property can help us to get the hotspot graph of science by using the keywords network, which is directly related to the subject of the paper. Also by analyzing this network, it is possible to forecast the future science hotspots.By analyzing keywords network from complex networks point of view, we are able to predict the future hotspots based on current trends, previous growth patterns that happened or with the power of different centrality measures like eigenvector etc. As an example, when a new keyword appears in a paper for the first time, a complex...
Design and Development of IoT-Based Sensor-Actuator Systems for Smart Buildings
, M.Sc. Thesis Sharif University of Technology ; Gholampour, Iman (Supervisor) ; Hajsadeghi, Khosrow (Supervisor)
Abstract
The use of the Internet of Things in buildings has become increasingly important. Meanwhile, sensors and actuators play a very important role. With the help of sensors, various data of residents' environment and behavior can be obtained and various parameters can be controlled through actuators. Data from the presence, measurement and decision making of the components of this structure in a building can be used to model and predict the behavior of residents with methods of machine learning, data mining and artificial intelligence such as deep learning and Gaussian processes, helping to achieve the goal of residents' comfort and energy saving.In the desired structure, the sensor- actuator...