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Unity Sliding Mode Controller Design for Active Magnetic Bearings System
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Active Magnetic Bearings (AMBs) are progressively being implemented in a wide variety of applications. Their exclusive appealing features make them suitable for solving traditional rotor-bearing problems using novel design approaches for rotating machinery.  In this paper, a linearized uncertain model of AMBs is utilized to develop a nonlinear sliding mode controller based on Lyapunov function for the electromechanical system. The controller requires measurements of the rotor displacements and their derivatives. Since the control law is discontinuous, the proposed controller can achieve a finite time regulation but with the drawback of the chattering problem. To reduce the effect of this problem, the gain of the unite vector term is evaluated as a function to state variables. As a result the proposed discontinuous controller regulates the state to the origin in a finite time in spite of the uncertainty in system model and the presence of external disturbances. These results are demonstrated via numerical simulations. In addition the chattering in system response in these results is within the acceptable range.

 

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Publication Date
Fri Jan 01 2010
Journal Name
Dar Majdalawi For Publication And Distribution
Technology of architecture and Interior Design, تكنلوجيا العمارة والفضاءات الداخلية
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Publication Date
Sat Dec 30 2017
Journal Name
Al-khwarizmi Engineering Journal
Design & Implementation of High Switching & Low Phase Noise Frequency Synthesizer
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This research  describes the design & implementation of frequency synthesizer using single loop Phase lock loop with the following specifications: Frequency range (1.5 – 2.75) GHz,Step size (1 MHz), Switching time 36.4 µs, & phase noise @10 kHz = -92dBc & spurious -100 dBc

  The development in I.C. technology provide the simplicity in the design of frequency synthesizer because it implements the phase frequency detector(PFD) , prescalar &  reference divider in single chip. Therefore our system consists of  a single chip contains (low phase noise PFD, charge pump, prescalar  & reference divider), voltage controlled oscillator , loop filter & reference oscillator. The single chip

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Publication Date
Sat Jan 01 2022
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees21gr
Optical characteristics of simulated design of parabolic trough solar concentrator
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Publication Date
Thu Apr 18 2013
Journal Name
International Journal Of Computer Applications
Design and Simulation of Hartley based Multi Orthogonal Band OFDM
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Recent advances in wireless communication systems have made use of OFDM technique to achieve high data rate transmission. The sensitivity to frequency offset between the carrier frequencies of the transmitter and the receiver is one of the major problems in OFDM systems. This frequency offset introduces inter-carrier interference in the OFDM symbol and then the BER performance reduced. In this paper a Multi-Orthogonal-Band MOB-OFDM system based on the Discrete Hartley Transform (DHT) is proposed to improve the BER performance. The OFDM spectrum is divided into equal sub-bands and the data is divided between these bands to form a local OFDM symbol in each sub-band using DHT. The global OFDM symbol is formed from all sub-bands together using

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Publication Date
Sat Aug 31 2024
Journal Name
International Review On Modelling And Simulations (iremos)
Prosthetic Hand: a Brief Survey of Design and Actuation Technologies
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Publication Date
Mon Jul 10 2023
Journal Name
Journal Of Engineering
Analysis and Optimum Design of Self Supporting Steel Communication Tower
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The present study deals with the optimum design of self supporting steel communication towers. A special technique is used to represent the tower as an equivalent hollow tapered beam with variable cross section. Then this method is employed to find the best layout of the tower among prespecified configurations. The formulation of the problem is applied to four types of tower layout
with K and X brace, with equal and unequal panels. The objective function is the total weight of the tower. The variables are the base and the top dimensions, the number of panels for the tower and member's cross section areas. The formulations of design constraints are based on the requirements of EIA and ANSI codes for allowable stresses in the members

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Publication Date
Sun Dec 15 2019
Journal Name
Al-academy
Iconic Form in Modern Graphic Design: علي محمد شواي غدير
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The graphic field invests the visual space then shows the shape by all means of expression that have a certain meaning. The research is interested in studying the iconic form in the modern graphic design through investing names and flags and the extent of their action in the social life and invest them from one to another looked at from viewpoint of trading and consumption and investing their wide popularity. The study problem is manifested in the following question:
1- Does the iconic form help in ad circulation?
The importance of the research lies in the following:
1- Reading the visual iconic form through deciphering its current symbols. The form combines a concept and a case or a form and meaning.

The theoretical fra

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Publication Date
Tue Jun 14 2016
Journal Name
Al-academy
The impact of modern global art movements on Graphic Design
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The significant shift in the Fine Arts, who led the avant-garde movements and creative which appeared in the modern, specifically in the mid-nineteenth century and early twentieth century era path, embodied in a clear show of new aesthetic value rejects traditional methods put in shape and color qualities She described the movements subjectivity or no formal, was intended to determine the direct function of expression and speech language in the visual arts away from the representation and simulation of reality was accompanied by the appearance of those fine movements directed towards a global approach to design carries features and clear in its organizations formalism of the most important move away from the symmetry and the adoption of

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Publication Date
Tue Aug 15 2023
Journal Name
Al-academy
Digital modeling and its technical variables in contemporary interior design
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The current research sheds light on an important aspect of the great and rapid development in the field of science and technology and modern manufacturing methods as a result of the scientific revolution resulting from the accelerated cognitive development, which prompted designers in general and interior design in particular to exploit and invest in digital technology and the development of digital control in the process of designing the industrial product for the purpose of creativity and innovation through these digital programs Digital models achieve the requirements and desires of the interior designer according to the creative skill using modern software with high efficiency And extreme accuracy that is consistent with the requirem

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Publication Date
Fri May 03 2019
Journal Name
Photonics
Design Investigation of 4 × 4 Nonblocking Hybrid Plasmonic Electrooptic Switch
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This paper proposes a compact, plasmonic-based 4 × 4 nonblocking switch for optical networks. This device uses six 2 × 2 plasmonic Mach-Zehnder switch (MZS), whose arm waveguide is supported by a JRD1 polymer layer as a high electro-optic coefficient material. The 4 × 4 switch is designed in COMSOL environment for 1550 nm wavelength operation. The performance of the proposed switch outperforms those of conventional (nonplasmonic) counterparts. The designed switch yields a compact structure ( 500 × 70   µ m 2 ) having V π L = 12   V · µ m , 1.5 THz optical bandwidth, 7.7 dB insertion loss, and −26.5 dB crosstalk. The capability of the switch to route 8 × 40 Gbps WDM signal is demonstrated successfully.

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