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Design High Efficient Reflectivity of Distributed Bragg Reflectors
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Bragg Reflectors consist of periodic dielectric layers having an optical path length of quarter wavelength for each layer giving them important properties and makes them suitable for optoelectronics applications. The reflectivity can be increased by increasing the number of layers of the mirror to get the required value. For example for an 8 layers Bragg mirror (two layers for each dielectric pair), the contrast of the refractive index has to be equal to 0.275 for reaching reflectivity > 99%. Doubling the number of layers results in a reflectivity of 99.99%. The high reflectivity is purely caused by multiple-interference effects. It can be analyzed by using different matrix methods such as the transfer matrix method (TMM) which is the simplest method to study the characteristic of devices with different alternating layers.

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Publication Date
Wed Dec 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
حول أسلوب تحليل التغاير المتعدد باستخدام تصميم قطع منشقة
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Analysis of Covariance consider to be quite important procedure to reduce the effect of some independents factors before going through the experiment.

By this procedure we can compare variances causes from the difference between treatments and error term variance of they are equals or less than consider to be not significant, otherwise if is significant.

We carry on with this comparison until we find the greatest covser for the significant variance flam the treatments.

There are methods can be used like least significant difference method, Duncan method and Turkeys' w-procedure and Student Newman.

Key Word: Analysis of variatio

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Publication Date
Sun Mar 17 2019
Journal Name
Baghdad Science Journal
A New Cipher Based on Feistel Structure and Chaotic Maps
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Chaotic systems have been proved to be useful and effective for cryptography. Through this work, a new Feistel cipher depend upon chaos systems and Feistel network structure with dynamic secret key size according to the message size have been proposed. Compared with the classical traditional ciphers like Feistel-based structure ciphers, Data Encryption Standards (DES), is the common example of Feistel-based ciphers, the process of confusion and diffusion, will contains the dynamical permutation choice boxes, dynamical substitution choice boxes, which will be generated once and hence, considered static,

            While using chaotic maps, in the suggested system, called

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Publication Date
Wed Dec 14 2022
Journal Name
Journal Of The College Of Basic Education
الادراك الشكلي وفق نظرية الجشتالت في تصميم الفضاءات الداخلية
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Man is distinguished by his ability to harmonize with himself and with his environment, so he always needs the process of sensation to know what is happening around him, and at the same time he needs perception to know and understand what is happening in his surroundings through sensation, that any realization of the perception of forms in the internal spaces can only take place The mental images that are stored and that differ between individuals according to culture and environment, they differ in the ability to see the depths of space through interior design, and the theory of form (gestalt) is one of the most important theories that extended its interpretations to the field of interior design art as the field in which it can be manifest

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Publication Date
Sat Feb 02 2019
Journal Name
Journal Of The College Of Education For Women
Design of an Electron Gun Using two Electrod Low Aberration Immersion Lens
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Abstract
A two electrode immersion electrostatic lens used in the design
of an electron gun, with small aberration, has been designed using
the finite element method (FEM). By choosing the appropriate
geometrical shape of there electrodes the potential V(r,z) and the
axial potential distribution have been computed using the FEM to
solve Laplace's equation.
The trajectory of the electron beam and the optical properties of
this lens combination of electrodes have been computed under
different magnification conditions (Zero and infinite magnification
conditions) from studying the properties of the designed electron
gun can be supplied with Abeam current of 5.7*10-6 A , electron
gun with half acceptance

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Publication Date
Wed Jan 01 2020
Journal Name
Journal Of Human Sport And Exercise - 2020 - Winter Conferences Of Sports Science
Test design to measure the cognitive processing speed of table tennis players
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Table tennis is considered one of the fast base sports that the player needs to have the speed of performance and awareness, especially in straight forward and back strikes, which is an important offensive skills, and the player success depends on his perception speed to the point of the fall of the ball in the arena of his competitor. But there is no way to measure cognitive processing speed. Therefore, the researchers sought to design a test that measures this ability to ensure its scientific evaluation, and then establish standard scores for this test for the players of the specialized school of table tennis, to help evaluate them objectively and move away from subjective estimates when evaluating and developing measuring instruments in

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Scopus (5)
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Publication Date
Sun Dec 01 2013
Journal Name
Diyala Journal Of Engineering Sciences
Design and Simulation of parallel CDMA System Based on 3D-Hadamard Transform
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Future wireless systems aim to provide higher transmission data rates, improved spectral efficiency and greater capacity. In this paper a spectral efficient two dimensional (2-D) parallel code division multiple access (CDMA) system is proposed for generating and transmitting (2-D CDMA) symbols through 2-D Inter-Symbol Interference (ISI) channel to increase the transmission speed. The 3D-Hadamard matrix is used to generate the 2-D spreading codes required to spread the two-dimensional data for each user row wise and column wise. The quadrature amplitude modulation (QAM) is used as a data mapping technique due to the increased spectral efficiency offered. The new structure simulated using MATLAB and a comparison of performance for ser

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Publication Date
Sun Apr 17 2016
Journal Name
Al-academy
Design trends of family dual-used in small spaces: محمد سعد الجميلي
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Comes interest in the subject matter in the selection of the Family industry globally as one of the important industries which have developed a clear and significant in recent years, to look at these products and designs to their functional importance have appeared in recent years, the phenomenon of the small spaces because of housing Population density showed the need to find a spare Furniture fit these small spaces On this basis, determine the objective of this research is to arrive at a design techniques for dual-family employee for small spaces research sample included a double family manufactured in laboratories industry Furniture in Baghdad and local research sample includes family double Decker.Research focused on the first four c

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Publication Date
Thu Oct 01 2020
Journal Name
International Journal Of Electrical And Computer Engineering (ijece)
Design of an adaptive state feedback controller for a magnetic levitation system
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This paper presents designing an adaptive state feedback controller (ASFC) for a magnetic levitation system (MLS), which is an unstable system and has high nonlinearity and represents a challenging control problem. First, a nonadaptive state feedback controller (SFC) is designed by linearization about a selected equilibrium point and designing a SFC by pole-placement method to achieve maximum overshoot of 1.5% and settling time of 1s (5% criterion). When the operating point changes, the designed controller can no longer achieve the design specifications, since it is designed based on a linearization about a different operating point. This gives rise to utilizing the adaptive control scheme to parameterize the state feedback controll

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Scopus (8)
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Publication Date
Wed Jan 01 2020
Journal Name
Fme Transactions
Development of automated liquid filling system based on the interactive design approach
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The automatic liquid filling system is used in different applications such as production of detergents, liquid soaps, fruit juices, milk products, bottled water, etc. The automatic bottle filling system is highly expensive. Where, the common filling systems required to complex changes in hardware and software in order to modify volume of liquid. There are many important variables in the filling process such as volume of liquid, the filling time, etc. This paper presents a new approach to develop an automatic liquid filling system. The new proposed system consists of a conveyor subsystem, filling stations, and camera to detect the level of the liquid at any instant during the filling process. The camera can detect accurately the leve

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Publication Date
Thu Jun 01 2023
Journal Name
Advances In Mechanical Engineering
3D-shape formation of blood vessels based on computer aided design system
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This paper proposes and tests a computerized approach for constructing a 3D model of blood vessels from angiogram images. The approach is divided into two steps, image features extraction and solid model formation. In the first step, image morphological operations and post-processing techniques are used for extracting geometrical entities from the angiogram image. These entities are the middle curve and outer edges of the blood vessel, which are then passed to a computer-aided graphical system for the second phase of processing. The system has embedded programming capabilities and pre-programmed libraries for automating a sequence of events that are exploited to create a solid model of the blood vessel. The gradient of the middle c

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