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Sensitivity Analysis and Optimal Control of a Nano-Newton CMOS-MEMS Capacitive Force Sensor for Biomedical Applications
, M.Sc. Thesis Sharif University of Technology ; Meghdari, Ali (Supervisor) ; Selk Ghafari, Ali (Supervisor)
Abstract
In the first part of the thesis, we introduce the structure of a Nano-Newton CMOS-MEMS capacitive force sensor. This force sensor has been utilized out-of-plane sensing mechanism with high accuracy and reliability. Also, we discuss about sensitivity analysis of this force sensor. The largest change of capacitance (increased capacitance + decreased capacitance) occurs in ℓ=2/3. Sensitivity for increased capacitance grows by 8.33% and for decreased capacitance grows by 2.27%. The proposed method provides useful guidelines to increase the sensitivity of the sensor up to 250%. In the second part, a fixed structure controller, PID type, is proposed to control and suppress the in-plane vibration...
Modeling and Nonlinear Control of Two Novel Linear Motors
, M.Sc. Thesis Sharif University of Technology ; Ghaemi Osgouie, Kambiz (Supervisor) ; Khayyat, Amir Ali Akbar (Supervisor)
Abstract
Different types of motion mechanisms can be found in any complicated or simple mechanical structure and linear motion is one of the most frequently used mechanisms for sure. In recent years, a wide variety of designs are developed to create linear motion, each one having many positive and negative points. Among already existing designs, those based on linear actuation are more considerable compared to those using a mechanical convertor to transform rotary motion to linear motion. This thesis presents two newly designed linear motors which utilize linear electromagnet actuators in their structures. In this study nonlinear models are developed for two linear motors. Although all conditions and...
Semi Active Vibration Control of A Marine Offshore Structure Using Magnetorheological Dampers
, M.Sc. Thesis Sharif University of Technology ; Abolghasem, Zabihollah (Supervisor)
Abstract
Marine offshore structures are huge structures constructed in very harsh environments, like oceans and seas. These structures are highly exposed vibration due to ocean’s waves, wind, helicopter landing, etc. Preventing the damage to these structures due unpredicted vibration using a semi active vibration control is being considered. Magnetrorehological (MR) dampers have been used as active element to control the vibration and to provide the structural integrity of the structure. Providing high dynamic range, lower power requirements, large force capacity, robustness, and safe manner operation in case of fail made the MR dampers attractive devices to passive, semi-active and active control...
Semi Active Vibration Control of a Passenger Car Using Magnetorheological Shock Absorber
, M.Sc. Thesis Sharif University of Technology ; Zabihollah, Abolghasem (Supervisor)
Abstract
This project is intended to introduce a semi-active control for suspension systems of passenger cars wherein, in addition to usual dampers, the damper using Magnetorheological (MR) fluid instead of ordinary oil is used. In order to model the suspension system, a mass-spring model with eight degree-of-freedoms without considering the effect of car velocity is developed. A semi-active vibration control is presented to reduce the amplitude of automotive vibration caused by the alteration of road profile. In order to design a suitable control mechanism, first, an optimal control algorithm, Linear Quadratic Regulator (LQR) and Linear Quadratic Gaussian (LQG), are used to control the system;...
A Fully Differential Highly Linear Low Power Ultra Wideband LNA
, M.Sc. Thesis Sharif University of Technology ; Haj Sadeghi, Khosro (Supervisor)
Abstract
This work uses a hierarchical approach for designing the integrated UWB LNA in MOSFET technology. It first offers a brief treatment of the two important types of noise: the thermal noise of channel and the gate-induced noise, in MOSFET. Then the CS and CS-CG configurations for narrow-band LNAs are considered and the requirements for the wide-band operation in UWB are specified. Noise cancelling technique is also introduced, while five wideband prototype designs, with the noise-cancelling technique used in two designs, are re-examined and tested by simulation. Some proposed methods are then applied to these designs for better performance and obtaining practical insight. The final main...
Packet Loss Replacement in VOIP Using Linear Prediction Method
, M.Sc. Thesis Sharif University of Technology ; Ghorshi, Mohammad Ali (Supervisor) ; Mortazavi, Mohammad (Supervisor)
Abstract
In real-time packet-based communication systems one major problem is misrouted or delayed packets which result in degraded perceived voice quality. If some speech packets are not available on time, the packet is known as lost packet. The easiest task of a network terminal receiver is to replace silence for the duration of lost speech segments. In a high quality communication system in order to avoid quality reduction due to packet loss a suitable method and/or algorithm is needed to replace the missing segments of speech.There are several methods which have been proposed to reduce the effect of packet loss such as Waveform Substitution, High Order Autoregressive, Linear Prediction (LP),...
Face Recognition Improvement Using Boosting Method
, M.Sc. Thesis Sharif University of Technology ; Kasaei, Shohreh (Supervisor)
Abstract
Biometrics has been long known to recognize persons based on their physical and behavioral characteristics. Face recognition (FR) is one of such biometrics that has received a considerable attention in recent years both from the industry and research communities. As the boosting framework has shown good performance in face recognition, it has been adopted in this work. This thesis deals with pattern recognition methods such as linear discriminant analysis (LDA) and machine learning approaches such as boosting which are integrated to overcome the technical limitation of existing FR methods. However, LDA-based methods often suffer from the so-called “small-sample-size” (SSS) problem arising...
Modeling of Delamination Buckling of Composite Laminates
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
The fiber-reinforced composite materials are used widely because of their high strength-to-density and stiffness-to-density ratios. The laminated composites are susceptible to delamination. When a delaminated composite plate is subjected to in-plane compression, buckling in the delaminated region may occur. In this thesis, after verification and validation of the models, the effect of the length of the longest and near surface delamination and beneath delaminations on critical buckling load of composite laminates are investigated. Numerical study is carried out to determine the buckling load of clamped composite plates with different symmetric and anti symmetric stacking sequences. The...
Evaluation of Demand Modifier Factor ,M, in FEMA356 for Concrete Structures Under Near-Field Earthquakes
, M.Sc. Thesis Sharif University of Technology ; Rahimzadeh Rofooei, Fayyaz (Supervisor)
Abstract
On the average, ten thousand people die annually due to earthquakes. A UNESCO study gives damage losses amounting to ten billion dollars within the years 1926 to 1950 from earthquakes. These data shows the importance of earthquake issue that causes the scientists to pay special attention to this subject. In despite of significant improvements in many of scientific fields, earthquake is still remains as an unknown event without the possibility of predicting its time and location of occurrence. Because of that, a large effort has been paid for rehabilitation of structures to prevent the human loss and maintaining the necessary life safety. In this regard, various guidelines have been proposed...
Efficient Data Collection in Wireless Sensor Networks
, M.Sc. Thesis Sharif University of Technology ; Hemmatyar, Ali Mohammad Afshin (Supervisor)
Abstract
Wireless Sensor Networks (WSNs) consist of few hundred to thousand sensor nodes that are usually deployedrandomly in a sensing field. The duty of sensor nodes is to sense the environment for data collection and sending these data to a sink node for future processes. Sensor nodes are equipped with a non-rechargeable battery. Hence, network lifetime is an important issue in WSNs. When a static sink node is used in a WSN, sensor nodes that are located in the neighborhood of the sink node willdrain out of energy faster than other sensor nodes which are farther away from the sink node, because traffic load is heavier on sensor nodes which are closer to the sink node. This problem is named “the...
Computational Modeling and Mining of Trust and Reputation in Social Networks Based on Soft Computing Approach
, M.Sc. Thesis Sharif University of Technology ; Azmi, Reza (Supervisor) ; Sedighi Moshkenani, Mohsen (Supervisor)
Abstract
Nowadays trust has become one of the main challenges of every online social network. The open and decentralized nature of Peer-to-Peer network makes it vulnerable to be exploited by malicious users to distribute tampered and harmful contents. We propose a dynamic computational trust model based on a neuro-fuzzy approach and implemented it on Gnutella network. The model is a novel application of control systems approach for evaluating trust and reputation in P2P networks. We utilize Local Linear Model Tree (LOLIMOT) to perform a nonlinear dynamic system identiffcation and thus to approximate trust. The performance of our reputation-based trust model is evaluated by simulation. We create a...
Joint Disrtibuted Source and Network Coding
, M.Sc. Thesis Sharif University of Technology ; Movaghar Rahimabadi, Ali (Supervisor)
Abstract
Network coding, as a novel technique, suggests that the intermediate nodes of a network can combine independent flows to optimize the usage of a shared communication channel. Also, distributed source coding, exploits the joint statistics of correlated information sources to reduce the volume of transmitted information. Surprisingly, it has been shown that linear network codes are able to compress correlated sources. In this project, we have focused on this problem, i.e. joint distributed source and network coding. We have two important contributions with different directions. First we give a practical design for joint coding. Second, we use an evolutionary approach to find the best placement...
A Mutual Predictive Scheduling Model for Customer Order Prioritizing & Manufacture Scheduling Inspired by Industry 4.0
, M.Sc. Thesis Sharif University of Technology ; Fatahi Valilai, Omid (Supervisor)
Abstract
This study, with integrated approach to the POM problem, has developed a linear mutual MILP model with the hybrid MTS / MTO operational approach on the OAS problem in industry 4.0 environment for the Shahin Plastic Manufacturing Company. This enabled an integrated PM with the production in the scheduling model. The model objective function has minimized costs and maximized the company profits. It also maximized customer satisfaction by minimizing the tardiness and earliness time in producing orders. To implement this model in the factory decision-making system, measures and modifications have been made to the MIS structure of the corporate departments. Measures include the creation of cloud...
A Project Portfolio Selection Method for Iranian Private Construction Companies
, M.Sc. Thesis Sharif University of Technology ; Shadrokh, Shahram (Supervisor)
Abstract
The construction industry is one of the main industries in Iran, and plays a fundamental role in Iran’s economy, because construction has impact on most of other industries by its vast value chain. Selecting right sets of projects is considerably crucial for construction organizations to successfully achieve their competitive advantages and corporate strategies. Due to limited resources and dynamic changes in Iran’s construction business environment, this kind of selection is quite challenging for construction organizations. Beside’s over hundreds of selection tools, techniques, and complex selection frameworks were developed or recommended by academics and practitioners to smooth the...
Numerical Simulation of Cellular Structure of Detonation Wave and Evaluation of Linear Instability Analysis
, Ph.D. Dissertation Sharif University of Technology ; Farshchi, Mohammad (Supervisor)
Abstract
Experimental studies of regular cell structure of a weak detonation wave in a gaseous mixture of hydrogen and oxygen diluted with argon have shown that for a constant initial thermodynamic condition, the final cell size differs by repeating the tests. The question is that if these different final cell sizes for a constant initial condition are because of test errors, or the experiments would lead to a domain of solution in the form of different final cell sizes? Therefore, the aim of this study is to investigate, numerically, the evolution process and domain of variation of cellular structure of a weak detonation, and their dependency to unstable wavelengths obtained from linear instability...
Energy Management of a Residential Prosumer Employing Machine Learning Techniques
, M.Sc. Thesis Sharif University of Technology ; Moeini Eghtaei, Moein (Supervisor)
Abstract
This thesis proposes an energy management model for a residential prosumer building which is a multi-carrier energy hub in a grid-connected mode. Power may be bought and sold between the building energy system and the power grid. Solar panels and solar water heaters are integrated into the building's energy system to create electricity and heat, which may be used in a variety of ways: used immediately to meet the home's demands, stored in batteries and heat banks for later use, or sold back to the power grid to earn income. The energy dispatch is managed such that the overall energy consumption cost is minimized, considering the variation in electricity price (grid tariff), renewable energy...
Development of an Optimal Technique to Construct the Energy Spectrum of the Hpge Detector Using the Output Spectrum of the Nai Detector, with the Help of Soft Computing Algorithms
, M.Sc. Thesis Sharif University of Technology ; Vosoughi, Naser (Supervisor)
Abstract
Gamma ray spectroscopy has a special place in the industrial applications of nuclear radiation. Currently, the most common device for gamma ray detection and spectroscopy is the sodium iodide scintillation detector. Long life and high efficiency and reasonable price of these detectors are the reasons for the development of the use of these detectors in industries and laboratories. But these detectors in the classification of energy sensitive detectors are considered as detectors with low resolution. The presence of broad peaks in the gamma ray spectrum of this detector increases the possibility of interference of peaks related to different energies and makes it difficult to identify the...
Development of Water, Energy, and Food Nexus Model Considering Agricultural Development Policies
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
Due to increasing population and economic growth that has improved the living standards of human societies, the resources of the three sectors of water, energy, and food are in short supply. The close connection between these three parts requires integrated policy-making. In this research, for an integrated water, energy, and food system, an integer linear programming model has been developed for the optimal selection of technologies, their capacity, and their water and energy flow. Agricultural development policies include the construction of greenhouses and the use of renewable energy technologies and wastewater treatment technology to supply energy and water to the domestic and...
Modelling and Optimization of Long-Term Heat Storage Systems in Greenhouses
, M.Sc. Thesis Sharif University of Technology ; Roshandel, Ramin (Supervisor)
Abstract
Heating demand required for greenhouses is mainly met by fossil fuels. On the other hand, anxieties over usage of fossil fuels have led the societies to move toward renewable energies. With this in mind, the purpose of this research is to analyze using both solar energy for satisfying the heating demand of greenhouses and heat storage for compensating the intermittence of renewable energy.Considering the mentioned points, in the current research, a linear optimization framework has been developed for design and operation of energy systems including long-term heat storage to meet heating demand of greenhouses. The objective of this framework is to minimize annual cost. The developed method...