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alkej-219
Intelligent H2/H∞ Robust Control of an Active Magnetic Bearings System
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Abstract

Robust controller design requires a proper definition of uncertainty bounds. These uncertainty bounds are commonly selected randomly and conservatively for certain stability, without regard for controller performance.  This issue becomes critically important for multivariable systems with high nonlinearities, as in Active Magnetic Bearings (AMB) System. Flexibility and advanced learning abilities of intelligent techniques make them appealing for uncertainty estimation. The aim of this paper is to describe the development of robust H2/H controller for AMB based on intelligent estimation of uncertainty bounds using Adaptive Neuro Fuzzy Inference System (ANFIS).  Simulation results reveal that the robust controller design objectives of wide bandwidth and improved performance are satisfied for a wide range of frequency variations. It can be concluded that the intelligent uncertainty weighting functions can precisely compensate for the effects of modelling errors and nonlinearities in the system.

Keywords: Active Magnetic Bearings (AMB) , Adaptive Neuro Fuzzy Inference System (ANFIS),  H2/H  robust controller, modelling errors, uncertainty bounds.

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Publication Date
Sat Mar 01 2008
Journal Name
Al-khwarizmi Engineering Journal
Corrosion of Carbon Steel Pipeline in Flow System of water Sweetening Plant
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The electrochemical behavior of carbon steel in water sweetening station in Libya has been studied in the range of ( 293–333 oC) using weight loss technique. Measurements were carried out over a range of Reynolds number (5000 – 25000).An apparatus was designed for studying the corrosion process in the turbulent regime, which is of industrial significance. It was found that The corrosion rate of carbon steel in water sweetening station is under diffusion control and increases with increasing Reynolds number. On the other hand the variation of corrosion rate with temperature in the range of (293–333 oC) was found to follow Arrhenius equation and the activation energy approximately the same except at low Reynolds

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Publication Date
Fri Apr 01 2011
Journal Name
Desalination
Cathodic protection system of copper–zinc–saline water in presence of bacteria
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Rate of zinc consumption during the cathodic protection of copper pipeline which carries saline water was measured by weight loss technique in the absence and presence of bacteria. Variables studied were solution flow rate, temperature, time and NaCl concentration. It was found that within the present range of variables; the rate of zinc consumption increases with the increase of all operating conditions. The presence of bacteria increases the zinc consumption. Fourth order multi-term model and one-term model were suggested to represent the consumption data. Nonlinear regression analysis was used to estimate the coefficients of these models, while statistical analysis was used to determine the effect of each coefficient. Both models were re

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Publication Date
Wed Jan 01 2020
Journal Name
Journal Of Southwest Jiaotong University
Evaluation of Photovoltaic Solar Power of a Dual-Axis Solar Tracking System
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In this research project, a tip-tilting angle of a photovoltaic solar cell was developed to increase generated electrical power output. An active, accurate, and simple dual-axis tracking system was designed by using an Arduino Uno microprocessor. The system consisted of two sections: software and apparatus (hardware). It was modified by using a group of light-dependent resistor sensors, and two DC servo motors were utilized to rotate the solar panel to a location with maximum sunlight. These components were arranged in a mechanical configuration with the gearbox. The three locations of the solar cell were chosen according to the tilt angle values, at zero angles, which included an optimal 33-degree angle for the Baghdad location and

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Publication Date
Mon Jun 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Automatic Optimization System of Cutting Condition for Different Types of Machining Processes
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This research aims at calculating the optimum cutting condition for various types of machining methods, assisted by computers, (the computer program in this research is designed to solve linear programs; the program is written in v. basic language). The program obtains the results automatically, this occur through entering the preliminary information about the work piece and the operating condition, the program makes the calculation actually by solving a group of experimental relations, depending on the type of machining method (turning, milling, drilling). The program was transferred to package and group of windows to facilitate the use; it will automatically print the initial input and optimal solution, and thus reduce the effort and t

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Publication Date
Fri Jan 01 2021
Journal Name
University Of Southern Queensland
An Investigation of Leadership Style and the Strategic Planning Process of Public and Private Colleges in Iraq: An Empirical Study
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Globalisation and rapid environmental change have created many challenges for public and private organisations across Iraq as a developing country, particularly in the higher education sector. This includes, for example, decreases in government funding; increased demand for higher education; a need for economic transformation, and related competitiveness of organizations. Such challenges require exceptional leaders and strategic planning in order to take action to improve. In Iraq, the higher education sector is still one of the main foundations in progressing the knowledge economy. Studies into leadership style, strategic planning processes, and the importance of leadership and organisational culture to an organisation’s success have bee

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Publication Date
Wed Jan 01 2020
Journal Name
Research Journal Of Pharmacy And Technology
<i>Insilico</i> and <i>in vitro</i> Approach for Design, Synthesis, and Anti-proliferative Activity of Novel Derivatives of 5-(4-Aminophenyl)-4-Substituted Phenyl-2, 4-Dihydro-3<i>H</i>-1, 2, 4-Triazole-3-Thione
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Publication Date
Sun Apr 30 2017
Journal Name
Journal Of Engineering
Sustainable Roadway Planning: A Model for a Proposed Rating System in Iraq
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     The goal of the research is to develop a sustainable rating system for roadway projects in Iraq for all of the life cycle stages of the projects which are (planning, design, construction and operation and maintenance). This paper investigates the criteria and its weightings of the suggested roadway rating system depending on sustainable planning activities. The methodology started in suggesting a group of sustainable criteria for planning stage and then suggesting weights from (1-5) points for each one of it. After that data were collected by using a closed questionnaire directed to the roadway experts group in order to verify the criteria weightings based on the relative importance of the roadway related impacts

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Publication Date
Mon May 15 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Solving System of Linear Fredholm Integral Equations of Second Kind Using Open Newton-Cotes Formulas
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In this paper, the linear system of Fredholm integral equations is solving using Open Newton-Cotes formula, which we use five different types of Open Newton-Cotes formula to solve this system.  Compare the results of suggested method with the results of another method (closed Newton-Cotes formula)    Finally, at the end of each method, algorithms and programs developed and written in MATLAB (version 7.0) and we give some numerical examples, illustrate suggested method

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Publication Date
Wed Jul 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Classical Continuous Optimal Control for Quaternary Nonlinear Parabolic Boundary Value Problems with State Vector Constraints
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This paper aims to study the quaternary classical continuous optimal control problem consisting of the quaternary nonlinear parabolic boundary value problem, the cost function, and the equality and inequality constraints on the state and the control. Under appropriate hypotheses, it is demonstrated that the quaternary classical continuous optimal control ruling by the quaternary nonlinear parabolic boundary value problem has a quaternary classical continuous optimal control vector that satisfies the equality constraint and inequality state and control constraint. Moreover, mathematical formulation of the quaternary adjoint equations related to the quaternary state equations is discovered, and then the weak form of the quaternary adjoint

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Publication Date
Sat Mar 01 2014
Journal Name
Journal Of The College Of Languages (jcl)
Pragmatic Presupposition: An ExtraLinguisitic Concept
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Presupposition, which indicates a prior assumption, is a vital notion in both semantic and pragmatic disciplines. It refers to assumptions implicitly made by interlocutors, which are necessary for the correct interpretation of an utterance. Although there is a general agreement that presupposition is a universal property of Language, there are various propositions concerning its nature. However, this research work proposes that presupposition is a contextual term, thus, is more pragmatic than semantic in its nature.Although Semantics and Pragmatics are two distinct disciplines, they are interrelated and complementary to each other, since meaning proper involves both, and since there is no clear borderline between the two disciplines. How

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