Preparation of Nano Fluid from Carbon Nano Structures with High Surface Area in Order to Improve the Heat Transfer Coefficient in Heat Exchangers

, M.Sc. Thesis Sharif University of Technology Naghash Chimeh, Amir Saleh (Author) ; Sattari, Sorena (Supervisor) ; Rashidi, Alimorad (Co-Advisor)

Abstract

In this research convective heat transfer coefficient enhancement of nanofluids prepared from high surface area graphene has been investigated in laminar flow in the developing region. The nanofluid has been prepared from nanoporous graphene with high surface area and with concentration of 0.025 to 0.1 %wt. Deionized water has been used as the base fluid and a type of Ter-Polymer has been utilized as the surfactant. The results indicate that thermal conductivity of nanofluid with concentration of 0.1 %wt remains quite constant, with only %3.8 enhancement, while convective heat transfer coefficient improves significantly, with 34% enhancement. The behavior of this enhancement related to the...

Network Traffic Generation Focused on Flash Crowd Anomaly

, M.Sc. Thesis Sharif University of Technology Saleh, Zahra (Author) ; Jahangir, Amir Hossein (Supervisor)

Abstract

Flash Crowd traffic generation can be used as a metrics for measuring the resiliency and performance of a server. Also, it can provide a framework for verification and test of Intrusion detection systems (IDS) and Intrusion protection systems (IPS). Common traffic generation methods mimic timing and content of input traffic or regenerate input traffic by extracting its statistic distribution. So all of them need input traffic, while properties of Flash Crowd are different in the various servers and situations and there is no guaranty in existence of such samples of traffic for all servers. In this thesis, we introduce and use a new method for traffic generation without the need for input...

Simultaneous Measurements of Multiple Vital Signs using Doppler Radar

, M.Sc. Thesis Sharif University of Technology Naghash, Fatemeh (Author) ; Behnia, Fereidoon (Supervisor)

Abstract

This study presents a non-contact heart rate monitoring system using a rotating radar system. Vital signals from individuals are detected through radar, influenced by a distance and the antenna gain-proportionality factor. In the proposed method, the number of individuals within the radar range is first estimated based on Power Spectral Density (PSD) analysis. Using Independent Component Analysis (ICA), individual signals are extracted from the mixture composed of the linear combination of signals affected by the Doppler shift. The method uses a Constant False Alarm Rate (CFAR) threshold on the PSD, enabling simultaneous heart rate monitoring for multiple persons. Additionally, a...

A Hybrid Approach for Evaluation and Improvement of Business Process under Uncertainty

, M.Sc. Thesis Sharif University of Technology Jalali Chimeh, Mahdi (Author) ; Haji, Babak (Supervisor)

Abstract

Business process management (BPM) is an approach which helps managers to gain success in their organization by becoming capable of identifying and developing their processes. Process improvement is a difficult and important step in BPM since modern organizations have a huge number of processes and activities with complex and complicated relationships and interrelationships. In this work our goal is to rank and prioritize processes based on operational limitations of the organization such as budget, human resources, consumer resources and also relationships among processes have been considered and finally develop a portfolio of processes which are vital and essential for improvement....

Experimental assessment of convective heat transfer coefficient enhancement of nanofluids prepared from high surface area nanoporous graphene

, Article International Communications in Heat and Mass Transfer ; Volume 78 , 2016 , Pages 127-134 ; 07351933 (ISSN) Naghash, A. S ; Sattari, S ; Rashidi, A. M ; Sharif University of Technology

Elsevier Ltd 2016

Abstract

In this research convective heat transfer coefficient enhancement of nanofluids prepared from high surface area graphene has been investigated in laminar flow in the developing region. The nanofluid has been prepared from nanoporous graphene with high surface area and with concentration of 0.025 to 0.1 wt.%. Deionized water has been used as the base fluid and a type of Ter-Polymer has been utilized as the surfactant. The results indicate that thermal conductivity of nanofluid with concentration of 0.1 wt.% remains quite constant, with only 3.8% enhancement, while convective heat transfer coefficient improves significantly, with 34% enhancement. The behavior of this enhancement related to the...

Non-fragile Static Output Feedback Control with Sparse Gain Matrix

, M.Sc. Thesis Sharif University of Technology Iraniparast, Amir Hossein (Author) ; Tavazoei, Mohammad Saleh (Supervisor) ; Nobakhti, Amin (Supervisor)

Abstract

One of the issues in the design and synthesis of the state or output feedback controller is the issue of fragility as the existence of disturbance in the coeﬃcients of the designed controller causes instability in the controlled closed-loop system or leads to deterioration of its performance. The need to consider this point results in some novel approaches for designing the non-fragile controllers. Accordingly, defining criteria for measuring fragility is crucial.As well, due to the considered practical problems in the implementation of ordinary designed robust and optimal controllers, non-reachability of all the states of dynamical systems, and the boundedness for the quantity of the...

A Dynamic Scheduling Model with Multiple Process Planning Scenarios Using Markov Models

, M.Sc. Thesis Sharif University of Technology Fathollahi Chimeh, Mahsa (Author) ; Haji, Babak (Supervisor)

Abstract

Cloud Manufacturing have been provided the proper context for efficient and effective using from distributed and various sources for agile and fast responsiveness to various customer demands. Product request from customers lead to define the operations in shop-floor levels that must be process by production equipment in shop-floors. The planning and scheduling problem of this activities have been most important challenge for decision makers. Therefore, the development of ways and methods can exploit efficiently from distributed resources and in confront of customer reqirement have been adaptive is most important. In this study an adaptive approach can be considered in terms of assigning the...

Achievable Delay Margin by Using PID Fractional-Order Controllers

, M.Sc. Thesis Sharif University of Technology Afshari Saleh, Mohammad Hossein (Author) ; Tavazoei, Mohammad Saleh (Supervisor)

Abstract

This paper concerns the delay margin achievable using fractional order Proportional_Integral_Derivative controllers for linear time- invariant systems subject to variable, unknown time delays. The basic issue under investigation addresses the question: What is the largest range of time delay so that there exists a single fractional order Proportional_Integral_Derivative controller to stabilize the delay plants within the entire range? Delay margin is a fundamental measure of robust stabilization against uncertain time delays and poses a fundamental, longstanding problem that remains open except in simple, isolated cases. In this research, we develop explicit expressions of the exact delay...

Design and Fabrication of An Electromagnetic Actuation System for Generation of Desired Magnetic Field and Control of Magnetic Particles

, M.Sc. Thesis Sharif University of Technology Amiri Chimeh, Hadiseh (Author) ; Nejat Pishkenari, Hossein (Supervisor)

Abstract

Being harmless to living tissues makes magnetic robots very promising for medical applications. Furthermore, since these robots are driven by external magnetic fields, no actuators are needed to be placed on the robots, enabling them to come in very small dimensions if necessary. Motion control of small magnetic particles paves the way for future applications, such as deliberate drug-delivery, sampling, and lowinvasive surgeries.The goal of this research is to design and construct a platform for generating desired magnetic fields in order to control the motion of magnetic robots in threedimensional space. In order to do so, a system of eight electromagnetic coils with iron cores was built....

PLC Implementation of Fractional Order Controllers

, M.Sc. Thesis Sharif University of Technology Aghaee, Mehdi (Author) ; Tavazoei, Mohammad Saleh (Supervisor)

Abstract

In this thesis, various fractional order controllers (FOCs), e.g., FO-PID, FO-TID, CRONE and FO-Lead/Lag, are implemented using PLC. For this purpose first, several methods are used to approximate the differentiator and integral operators. Based on these methods, the equivalent rational transfer functions of the fractional order controllers are obtained. Then, using STEP7 software, the FOCs are implemented in Siemens PLC. Moreover, to facilitate the use of the implemented FOCs in the industry and to take full advantage of the controllers, WinCC software as an interface between human and machine (HMI) is used. The WinCC software enables the operator to access the PLC through a computer (PC)...

Study on Solution Existence in Tuning Fractional Order PD and PI Controllers

, M.Sc. Thesis Sharif University of Technology Badri, Vahid (Author) ; Tavazoei, Mohammad Saleh (Supervisor)

Abstract

In this study, some of robust and exact tuning methods for fractional order PD and PI controllers are investigated in order to extract their solution existence conditions. Using aforementioned methods needs solving a set of nonlinear equations to obtain desired controller parameters which satisfy the control objectives. Hence, one of the aims of this study is to find necessary and sufficient condition on tuning specifications which guarantee the applicability of the aforementioned methods. The achievable performance region of the methods is obtained through the extracted necessary and sufficient conditions. The other aim of this work is to investigate the uniqueness of the methods...

Evaluating the Performance of Quantitative Trading Strategies in the Gold Coin futures Maket of Iran Merchantile Exchange

, M.Sc. Thesis Sharif University of Technology Saleh, Armin (Author) ; Bahramgiri, Mohsen (Supervisor)

Abstract

Along with the development of electronic exchanges, accessibility to various data streams, increasing computing power, decreasing trading costs, and growing competition in financial investment industry, quantitative trading strategies or quantitative trading rules have developed rapidly in the recent decades. These strategies try to forecast the future price movements of risky assets from the historical market information in algorithmic ways or statistical ways and thus challenge the Efficient Market Hypothesis.
The increasing attention to these strategies and lack of related empirical studies in the financial markets of Iran, motivate the research in this area. Furthermore, despite its...

Five-degree-of-freedom robust control of a magnetic endoscopic capsule using an electromagnetic system

, Article Control Engineering Practice ; Volume 134 , 2023 ; 09670661 (ISSN) Sadeghi Boroujeni, P ; Nejat Pishkenari, H ; Amiri Chimeh, H ; Moradi, H ; Vossoughi, G ; Sharif University of Technology

Elsevier Ltd 2023

Abstract

Capsule endoscopy is a minimally invasive gastrointestinal diagnostic procedure. The active endoscopic capsule enables the physician to steer the device to any desired position and direction, resulting in a better diagnosis of the disease. Due to the model uncertainties and the existence of disturbances in the gastrointestinal system, traditional control methods cannot achieve robust performance and stability. To overcome this issue, in this paper, a robust sliding mode controller is proposed for 5 Degrees Of Freedom (DOF) control (3-DOF closed-loop control for position and 2-DOF open-loop control for orientation) of the capsule endoscope using an electromagnetic actuation system. The...

Numerical Investigation of Nano-Particles Dispersion and Deposition in Curved and Bifurcating Channels using Lattice Boltzmann Method

, M.Sc. Thesis Sharif University of Technology Tehrani Saleh, Ali (Author) ; Moosavi, Ali (Supervisor)

Abstract

Investigation of transport and deposition of aerosol particles attracts interests in many fields of sciences. Various numerical and computational methods has been utilized in particulate flows studies. In recent relevant researches lattice Boltzmann method has been widely used and is reported to be a robust and efficient method. In present study, numerical investigation of dispersion and deposition of aerosol particles is performed in curved and bifurcating channels using LBM. Fluid flow simulations are performed using LBM while one-way coupling Lagrangian point of view is used for particle tracking. As the first showcase, transport and deposition of aerosol particles in channel flow with...

Fractional PI Tuning for the First Order Plus Dead Time Processes

, M.Sc. Thesis Sharif University of Technology Paridari, Kaveh (Author) ; Tavazoei, Mohammad Saleh (Supervisor)

Abstract

In this thesis, a new method has been developed for tuning of fractional PI ( ) and fractional [PI] ( ) controllers for the first order plus dead-time ( ) systems. By using the performance-map method ( ) and based on phase and gain margins' criteria, a formula which is function of fractional order ( ) and normalized dead-time ( ) has been proposed for the proportional and integral coefficients. In addition, an equation has been given for the fractional order of controller to minimize the integrated absolute error ( ) index. Moreover, overshoot and settling-time of the step response of the system have been improved by dynamic setpoint weighting. Simulation results have shown that proposed...

Cross-Lingual Speaker Adaptation for Statistical Parametric Speech Synthesis

, M.Sc. Thesis Sharif University of Technology Saleh, Fatemeh Sadat (Author) ; Sameti, Hossein (Supervisor)

Abstract

Speech synthesis and its applications have been very attractive recently. The main purpose of this technique is to produce a speech signal with natural characteristics of human speech like prosody and emotion. Among all existing methods for speech synthesis, statistical parametric speech synthesis methods are more promising because ofhigher flexibility in comparison to other methods. One of the applications of speech synthesis is speech to speech translation. In these systems, the generated voice in target language should have the same characteristics as the input voice in source language. The main purpose of this research is to review and evaluate the cross lingual speaker adaptation...

Using Decoupling Techniques in Control of Fractional-Order TITO Systems

, M.Sc. Thesis Sharif University of Technology Azimi, Farzad (Author) ; Tavazoei, Mohamad Saleh (Supervisor)

Abstract

The purpose of this thesis is presenting some decoupling methods for fractional-order two input-two outputs (TITO) systems in order to using in control applications. To achieve this purpose, some methods which have been proposed for decoupling of integer-order systems have been studied and then generalized to be used in decoupling of the fractional-order systems. These methods are classified in two classes: state space based methods and transfer function based methods. Also, in this thesis the proposed decoupling methods have been used in control of some fractional-order TITO systems

Analysis of Oscillations in Linear Fractional Order Systems

, M.Sc. Thesis Sharif University of Technology Siami, Milad (Author) ; Tavazoei, Mohammad Saleh (Supervisor)

Abstract

This thesis studies undamped oscillations generated by marginally stable fractional order linear time invariant (LTI) systems. In this study, the concept of integral curve is developed for fractional order LTI systems. The proposed concept is obtained based on equivalent integer order linear time varying (LTV) systems. Then, an analytical approach is proposed to be used for harmonic analysis of such oscillations in marginally stable commensurate order LTI systems. Also, it is shown that the Q-semi norm of the limit sets for a trajectory of these systems can be analytically determined based on the Q-semi norm of the initial condition, where Q is a specific matrix. Moreover, this result is...

Numerical Methods in Simulation and Implementation of Proportional-Weighted Integral (PWI) Controllers

, M.Sc. Thesis Sharif University of Technology Rezaei, Davood (Author) ; Tavazoei, Mohammad Saleh (Supervisor)

Abstract

The main effort of this thesis is to present a numerical method to simulate and implement a special type of controllers, called proportional-weighted integral (PWI) controllers. For this purpose, at first mathematical equations of the fractional order proportional-integral controllers have been investigated in the time domain, and then by generalization of these controllers, the PWI controllers are achieved. Next the discretization of these controllers are carried out and the performance of the controllers are simulated by means of this discretization and comparison between these controllers and the conventional PI controllers has been held. After that a method for estimation of these...

Robust Stability Analysis of Uncertain LTI Distributed-Order Systems

, M.Sc. Thesis Sharif University of Technology Taghavian, Hamed (Author) ; Tavazoei, Mohammad Saleh (Supervisor)

Abstract

Distributed order dynamic systems are studied in this thesis. These systems incorporate distributed order operators to describe physical phenomena that naturally occur in diffusion, relaxation and viscoelasticity. Hence, the exact solutions of distributed order system of differential equations are derived analytically which are described by what we later call distributed order mittag-leffler functions. Then robust stability of distributed order LTI continuous time systems with uncertain weight functions and dynamic matrices is investigated and some sufficient conditions for stability/instability are introduced in this matter. Also, after discussing some of the properties of stability...