Determination of Occupant Comfortability in Ttall Buildings with Outrigger and Aerodynamic Characteristics

, M.Sc. Thesis Sharif University of Technology Hajiloo, Amin (Author) ; Bakhshi, Ali (Supervisor)

Abstract

In recent years, in Iran, like other countries tall buildings have been constructed as a solution to space limitation problem and modern architectural matters. By increase in building height,the flexibility against wind force increase, therefore necessitating the study of buildings behavior against wind force. Traditionally most of the research done, have dealt with performance of the buildings, probability of the failure, and the serviceability level all of which relates to the amount of force in elements, the stress existing in the structure, and the amount of displacement. A substantial factor in structures, especially in tall buildings, is the comfortability of their occupants which...

On the control of unknown continuous time chaotic systems by applying takens embedding theory

, Article Chaos, Solitons and Fractals ; Volume 109 , April , 2018 , Pages 53-57 ; 09600779 (ISSN) Kaveh, H ; Salarieh, H ; Hajiloo, R ; Sharif University of Technology

Elsevier Ltd 2018

Abstract

In this paper, a new approach to control continuous time chaotic systems with an unknown governing equation and limitation on the measurement of states, has been investigated. In many chaotic systems, disability to measure all of the states is a usual limitation, like in some economical, biological and many other engineering systems. Takens showed that a chaotic attractor has an astonishing feature in which it can embed to a mathematically similar attractor by using time series of one of the states. The new embedded attractor saves much information from the original attractor. This phenomenon has been deployed to present a new way to control continuous time chaotic systems, when only one of...

Chaos control in delayed phase space constructed by the Takens embedding theory

, Article Communications in Nonlinear Science and Numerical Simulation ; Volume 54 , 2018 , Pages 453-465 ; 10075704 (ISSN) Hajiloo, R ; Salarieh, H ; Alasty, A ; Sharif University of Technology

Elsevier B.V 2018

Abstract

In this paper, the problem of chaos control in discrete-time chaotic systems with unknown governing equations and limited measurable states is investigated. Using the time-series of only one measurable state, an algorithm is proposed to stabilize unstable fixed points. The approach consists of three steps: first, using Takens embedding theory, a delayed phase space preserving the topological characteristics of the unknown system is reconstructed. Second, a dynamic model is identified by recursive least squares method to estimate the time-series data in the delayed phase space. Finally, based on the reconstructed model, an appropriate linear delayed feedback controller is obtained for...

Adaptive delayed feedback chaos control of a class of uncertain chaotic systems subject to external disturbance

, Article Iranian Journal of Science and Technology - Transactions of Mechanical Engineering ; Volume 43 , 2019 , Pages 517-525 ; 22286187 (ISSN) Hajiloo, R ; Shahrokhi, M ; Salarieh, H ; Sharif University of Technology

Springer International Publishing 2019

Abstract

In this paper, an adaptive nonlinear delayed feedback control is proposed for stabilizing an unstable periodic orbit (UPO) of a class of uncertain chaotic systems using the sliding mode approach. The chaotic system is subjected to external disturbances with unknown bounds. Using the Lyapunov stability theorem and the concept of sliding mode control, an adaptive delayed feedback controller has been designed. The controller and adaptation law guarantee the asymptotic stability of the closed loop system on a periodic trajectory which can be sufficiently close to the UPO of the chaotic system. The capability of the proposed control method in stabilizing the UPO of chaotic systems is established...

Model-free chaos control in a chaotic henon-like system using takens embedding theory

, Article 5th International Conference on Control, Instrumentation, and Automation, ICCIA 2017, 21 November 2017 through 23 November 2017 ; Volume 2018-January , 2018 , Pages 80-85 ; 9781538621349 (ISBN) Hajiloo, R ; Salarieh, H ; Alasty, A ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2018

Abstract

In this paper, the problem of chaos control in a chaotic Henon-like system without using the governing equations of the system is investigated. It is also assumed that the system has only one measurable state. The time-series of the measurable state is used to stabilize chaos by a three-step method. First, using Takens embedding theory, a delayed phase space is reconstructed preserving the topological characteristics of the system. Then, an appropriate dynamic model is identified to estimate the time-series data in the reconstructed phase space. Finally, the unstable fixed point of the system is stabilized using an appropriate linear delayed feedback controller with controller gains...

Using Statistical Pattern Recognition on Gene Expression Data for Prediction of Cancer

, M.Sc. Thesis Sharif University of Technology Hajiloo, Mohsen (Author) ; Rabiee, Hamid Reza (Supervisor)

Abstract

The classification of different tumor types is of great importance in cancer diagnosis and drug discovery. However, most previous cancer classification studies are clinical based and have limited diagnostic ability. Cancer classification using gene expression data is known to contain the keys for addressing the fundamental problems relating to cancer diagnosis. The recent advent of DNA microarray technique has made simultaneous monitoring of thousands of gene expressions possible. With this abundance of gene expression data, researchers have started to explore the possibilities of cancer classification using gene expression data and quite a number of Pattern Recognition approaches have been...

Fuzzy support vector machine: An efficient rule-based classification technique for microarrays

, Article BMC Bioinformatics ; Volume 14, Issue SUPPL13 , 2013 ; 14712105 (ISSN) Hajiloo, M ; Rabiee, H. R ; Anooshahpour, M ; Sharif University of Technology

2013

Abstract

Background: The abundance of gene expression microarray data has led to the development of machine learning algorithms applicable for tackling disease diagnosis, disease prognosis, and treatment selection problems. However, these algorithms often produce classifiers with weaknesses in terms of accuracy, robustness, and interpretability. This paper introduces fuzzy support vector machine which is a learning algorithm based on combination of fuzzy classifiers and kernel machines for microarray classification.Results: Experimental results on public leukemia, prostate, and colon cancer datasets show that fuzzy support vector machine applied in combination with filter or wrapper feature selection...

Chaos Control in Delayed phase Space Constructed by the Takens' Embedding Theory

, M.Sc. Thesis Sharif University of Technology Hajiloo, Reza (Author) ; Salarieh, Hassan (Supervisor) ; Alasty, Aria (Supervisor)

Abstract

One of the most surprising lessons of dynamical systems theory is that the phase spaces of simple nonlinear systems may contain strange attractors. For certain simple systems, such as pendulum, direct observations of the phase space and finding strange attractors are possible. But physical systems in which all the relevant dynamical variables can be simultaneously monitored are relatively scarce. Takens’ theory shows how a time-series of measurements of a single observable state can be often used to reconstruct qualitative features of the phase space of the system. In this research, using the time-series of one measurable state, an algorithm is proposed to control chaos. The approach...

Introducing a Simulation-Based Model to Improve the Design and Layout of Workstations Inside Airport Terminals in Iran

, M.Sc. Thesis Sharif University of Technology Amini Esfidvajani, Amin Mohammad (Author) ; Alvanchi, Amin (Supervisor)

Abstract

The airport terminal is difficult to plan and design due to the different components and the intricate complexity of its parts. At the airport terminal, we face a queue system which simulation is always a good way to analyze. In addition, computer simulation using modern softwares with the capability to model different types of systems, including the airport terminal, while being less realistic than analytical models, is less costly than operational Exercise.In this study, a supportive approach for better and specific management of Iranian airport terminal buildings with discrete-event simulation is proposed, considering the need for managing the airport terminals building in the country and...

, M.Sc. Thesis Sharif University of Technology (Author) ; Alvanchi, Amin (Supervisor)

Abstract

Limited water resources in Iran have made dams an important part of the country’s infrastructure. As a result of the large number of in-progress and expected dam projects in the country, consideration of sustainability factors during planning, construction and operation phases of dam projects can create significant economical, social and environmental impacts in the long term. To come up with an inclusive sustainable development, new sustainability assessment approaches seek for sustainable development at the entire project’s life-cycle; they are looking for sustainable development at all design, construction, operation, maintenance and even demolition phases. In this research we have...

Investigation of the Reaction of Dithiocarbamic Acid Salts with Carbonyl Compounds (Ketones and Aldehydes), Epoxides and Ortho Esters

, M.Sc. Thesis Sharif University of Technology Hajiloo Shayegan, Mojtaba (Author) ; Mahmoodi Hashemi, Mohammed (Supervisor) ; Ziyaei Halimehjani, Azim (Co-Advisor)

Abstract

In the first section, for the first time, a reaction of dithiocarbamic acid salts with carbonyl compounds has been investigated in the presence of BF3.OEt2. The reaction is temperature dependent meaning that the reaction gives two different products at low and high temperatures. At 15-20 0C, the 2-iminium-1,3-dithietane is the main product.As the reaction temperature goes up, formation of gem-bis(dithiocarbamates) is dominant.In addition, deprotection of gem-bis(dithiocarbamates) was investigated by using of nitric acid as the only deprotecting agent. The structure of a 2-iminium-1,3-dithietane was confirmed by X-ray crystallographic analysis.
In the second and third sections, in our aim...

The Insider Threat: Analyzing and Modeling

, M.Sc. Thesis Sharif University of Technology Amin, Assiabi (Author) ; Hendesi, Faramarz (Supervisor)

Abstract

Nowadays, most of businesses are becoming computer-based. This trend causes the organizations to become more vulnerable to internal and external threats. Internal threats are done through insiders. Insiders unlike outsiders have capabilities which aid them to easily carry out their illicit activities. Unfortunately, most of research in computer security has focused on the outsider threats, whereas the most damaging is the result of insiders’ illicit activities.This dissertation addresses three primary necessities of the research in the area of insider threat: a consistent definition of insider threat, a classification of types of insider threats, and a classification of vulnerabilities which...

Design of a Plantwide Decentrlized Structure Controller for the Tennessee Eastman Challenge Problem

, M.Sc. Thesis Sharif University of Technology Molamofrad, Foozhan (Author) ; Nobakhti, Amin (Supervisor)

Abstract

This project focuses on the Tennessee East-man challange problem(TEP) and the impact of setpoint changes and controller tunning on plant performance and profitability. TE has four major units. it is an unstable system due to the reaction within the reactor and a recycle streamcausing snow ball effect. As a result the control of this system is not easy. The study has been conducted along two main directions. First, selecting the optimal values for the setpoints and applying them in the simulation. secondly, try to find better parameter for controller in simulation. Simulation is based on working of Ricker. In TEP like the other multivariable systems, it is ameanable to use a centralized...

Convex Methods for the Design of Low Order Dynamic Pre-Compensators

, M.Sc. Thesis Sharif University of Technology Shamgah, Laya (Author) ; Nobakhti, Amin (Supervisor)

Abstract

Decentralized control is a typical method for the design of industrial MIMO control systems. However, in most multivariable systems, the existence of large interactions limit the achievable performance of such controllers. In the Nyquist Array design method proposed by Rosenbrock, the system interactions can be reduced using a precompensator, such that a decentralized controller may be used with acceptable performance. A well designed pre-compensator will effectively decouple the system and the multivariable systems may be considered as a set of SISO systems. It is therefore obvious that the key element in the Nyquist Array design method is the design of the pre-compensator. There are two...

Integrity Analysis in the Time-Delay Systems

, M.Sc. Thesis Sharif University of Technology Eslami, Mostafa (Author) ; Nobakhti, Amin (Supervisor)

Abstract

Integrity of closed-loop systems with integral action control is characterized by using a series of successively more difficult to obtain conditions: Integral Stabilizable (IS), Integral Controllable (IC), Integral Controllable with Integrity (ICI), and Decentralized Integral Controllability (DIC). The IS condition requires that for a Linear Time-Invariant (LTI) finitedimensional (FD) plant, G(s), one finds a stabilizing decentralized controller with integral action. For G(s) to be IC, in addition to being IS, one should be able to reduce the gain of
all control loops by the same factor from a finite value to (but not including) zero without introducing instabilities. ICI requires that...

A Thesis Submitted in Partial Fulfillment of the Requirement for the Degree of Master of Science in Electrical Engineering

, M.Sc. Thesis Sharif University of Technology Negim, Mostafa (Author) ; Nobakhti, Amin (Supervisor)

Abstract

Intraction in multi input multi output (MIMO) system makes control of these systems difficult.There are two ways to control such systems; Centralized and Decentralized control. One way in which a centralized controller is designed is using a precompensator. With application of the pre-compensator, the MIMO sytem is decoupled into several SISO systems and one can control these seperatly. Almost all previews methods for the design of pre-compensator assume that the model of the plant containsno uncertainties.In this thesis a new method is proposed which takes into account model uncertaintes in the design of the pre-compensator.The form of the uncertainties considred an interval-parametric

Conditions for Integrity of Multivariable Systems with Input Saturation

, M.Sc. Thesis Sharif University of Technology Asgharzadeh, Abbas (Author) ; Nobakhti, Amin (Supervisor)

Abstract

Multivariable control systems as used in the industry usually contain integral action in order to improve tracking of the output with respect to step reference changes. These systems are usually subject to input saturation due to actuator or sensor nonlinearities. The aim of this work is find the conditions for the integrity concept of such multivariable system, e.g. IS, IC, ICI and DIC. First we develop the conditions on the controller gains necessary stabilize the systems and then show that these conditions can changes when one examines integrity conditions

Disturbance Reduction Servo Motor Controller Design and Implementation

, M.Sc. Thesis Sharif University of Technology Ahi, Behzad (Author) ; Nobakhti, Amin (Supervisor)

Abstract

The servomechanisms have wide industrial application such as robotics, Computer Numerical Control (CNC) machines, automated manufacturing and solar tracking. Several methods have already been proposed for servo motor control that the most important of them are Proportional Integral Derivative (PID), H2/H--, intelligent based controllers, and model predictive control. Problem specifications and user requirements, will determine the appropriate approach in each case. The aim of this thesis is construction of a real-life camera stabilizer to be used in the motion picture industry. Effects of base movement on the performance should be decreased by choosing appropriate sensors and control...

Disturbance Diagnosis In Plant-wide Processes

, M.Sc. Thesis Sharif University of Technology Juyandeh, Sepideh (Author) ; Nobakhti, Amin (Supervisor)

Abstract

In continous chemical process, disturbances usually propagate along the process. This project describes a data-driven method for identifying the direction of propagation of disturbances using historical process data. The concept is the application of Transfer Entropy, a method based on the conditional probability density functions that measures directionality of variation. For demonstration purposes the transfer entropy method is used to isolate the root-cause of the disturbance in the Tennassee Eastman benchmark process

Optimization of Sparse Control Structures in Multivariable Systems

, Ph.D. Dissertation Sharif University of Technology Babazadeh, Maryam (Author) ; Nobakhti, Amin (Supervisor)

Abstract

In this thesis, the optimal control structure selection and design of sparse multi-variable control systems is addressed. A fundamental challenge which frequently emerges in engineering, social, and economic sciences, is the optimal selection of a subset of elements, in order to maximally fulfil a design objective. In practice, it is required to solve this underlying selection problem in conjunction with a non-linear or non-convex optimization which is designed to ensure desired performance. The requirement to solve these two problems simultaneously is what makes it inherently difficult; one which has thus far eluded efforts to develop a systematic means of determining its solution. In spite...