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MODELING AND COMPARISON OF CLOSED-LOOP AND OPENLOOP ADAPTIVE OPTICS SYSTEMS
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Astronomers have known since the invention of the telescope that atmospheric turbulence affects celestial images. So, in order to compensate for the atmospheric aberrations of the observed wavefront, an Adaptive Optics (AO) system has been introduced. The AO can be arranged into two systems: closedloop and open-loop systems. The aim of this paper is to model and compare the performance of both AO loop systems by using one of the most recent Adaptive Optics simulation tools, the Objected-Oriented Matlab Adaptive Optics (OOMAO). Then assess the performance of closed and open loop systems by their capabilities to compensate for wavefront aberrations and improve image quality, also their effect by the observed optical bands (near-infrared band and visible band), the shape of the telescope aperture (circular and hexagonal) and the atmospheric seeing conditions. The results showed that open-loop systems perform better than closed-loop systems at good seeing and vice versa. Also showed that closed-loop provides stability in the correction process over time, while the open-loop is a faster phase compensator

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Publication Date
Tue Dec 01 2020
Journal Name
Al-khwarizmi Engineering Journal
Impact of using Double Layers Perforated Liners on the Acoustic Treatments of the Combustor Systems
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The response of the combustor’s liner to the air-flow that passes through it is the key reason for the combustion chambers noise, hence the instabilities of those chambers that decreases the mechanical efficiency of such sections, by increased its mechanical vibrations, which increases the failure rate created during originating of the cracks spreading by the shakes producing by the series of high-level frequencies. Accordingly, any work debating the impact of the context of liners in the combustion chamber can provide grasping for the combustion noise generated by the undesirable vibrations, and benefits the industrial firms to design an ideal production procedure which increases the lifespan of the combustor. The goal of this work is

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Publication Date
Wed Dec 01 2021
Journal Name
Computers & Electrical Engineering
Utilizing different types of deep learning models for classification of series arc in photovoltaics systems
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Publication Date
Fri Jun 01 2012
Journal Name
The Journal Of Engineering Research [tjer]
Thermal Performance of Solar Hot Water Systems Using a Flat Plate Collector of Accelerated Risers
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 This study focuses on a comparison of the performance of two similar locally-fabricated solar water heaters. One of the collectors features a new design for accelerated absorber; its risers are made of converging ducts whose exit area is half that of the entrance. The other collector is a conventional absorber, with risers of the same cross sectional area along its length. Each collector is the primary part of an indirect thermosyphon circulation solar hot water system. Both collectors face south with a fixed tilt angle of 33.3

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Publication Date
Fri May 15 2009
Journal Name
Journal Of Planner And Development
Study of Change in Regional Land Use Using Remote Sensing Technology and Geographic Information Systems / Study Area (Hawr Al Huweiza) for the Years 1973-1990-2004
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his project try to explain the using ability of spatial techniques for land cover change detection on regional level with the time parameter and did select for explain these abilities study case (Hewaizah marsh ) . this area apply to many big changes with the time. These changes made action on characters and behaviors of this area as well as all activities in it . This Project concerting to recognize the Using importance of remote sensing and GIS Methodology in data collecting for the changes of land use and the methodology for the analyses and getting the results for the next using as a base data for development and drawing the plans as well as in regional planning .This project focus on practical

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Publication Date
Tue Jan 01 2019
Journal Name
Desalination And Water Treatment
Numerical modeling of performance of olive seeds as permeable reactive barrier for containment of copper from contaminated groundwater
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Publication Date
Fri May 01 2020
Journal Name
Journal Of Engineering
Effect of Maximum Size of Aggregate on the Behavior of Reinforced Concrete Beams Analyzed using Meso Scale Modeling
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In this study, simply supported reinforced concrete (RC) beams were analyzed using the Extended Finite Element Method (XFEM). This is a powerful method that is used for the treatment of discontinuities resulting from the fracture process and crack propagation in concrete. The mesoscale is used in modeling concrete as a two-phasic material of coarse aggregate and cement mortar. Air voids in the cement paste will also be modeled. The coarse aggregate used in the casting of these beams is a rounded aggregate consisting of different maximum sizes. The maximum size is 25 mm in the first model, and in the second model, the maximum size is 20 mm. The compressive strength used in these beams is equal to 26 MPa.

The subje

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Publication Date
Tue Oct 01 2019
Journal Name
2019 12th International Conference On Developments In Esystems Engineering (dese)
Roadway Deterioration Prediction Using Markov Chain Modeling (Wasit Governorate/ Iraq as a Case Study)
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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of the statistical methods used to Forecast the size of the Iraqi GDP for the two sectors (public and private) for the period (2025-2016)
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Gross domestic product (GDP) is an important measure of the size of the economy's production. Economists use this term to determine the extent of decline and growth in the economies of countries. It is also used to determine the order of countries and compare them to each other. The research aims at describing and analyzing the GDP during the period from 1980 to 2015 and for the public and private sectors and then forecasting GDP in subsequent years until 2025. To achieve this goal, two methods were used: linear and nonlinear regression. The second method in the time series analysis of the Box-Jenkins models and the using of statistical package (Minitab17), (GRETLW32)) to extract the results, and then comparing the two methods, T

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Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison between the Methods of Ridge Regression and Liu Type to Estimate the Parameters of the Negative Binomial Regression Model Under Multicollinearity Problem by Using Simulation
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The problem of Multicollinearity is one of the most common problems, which deal to a large extent with the internal correlation between explanatory variables. This problem is especially Appear in economics and applied research, The problem of Multicollinearity has a negative effect on the regression model, such as oversized variance degree and estimation of parameters that are unstable when we use the Least Square Method ( OLS), Therefore, other methods were used to estimate the parameters of the negative binomial model, including the estimated Ridge Regression Method and the Liu type estimator, The negative binomial regression model is a nonline

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Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
A comparison Some of Methods for Estimating Survival Function for Truncated Exponential Distribution
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Exponential distribution is one of most common distributions in studies and scientific researches with wide application in the fields of reliability, engineering and in analyzing survival function therefore the researcher has carried on extended studies in the characteristics of this distribution.

In this research, estimation of survival function for truncated exponential distribution in the maximum likelihood  methods and Bayes first and second method, least square method and Jackknife dependent in the first place on the maximum likelihood method, then on Bayes first method then comparing then using simulation, thus to accomplish this task, different size samples have been adopted by the searcher us

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