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Comparison of classical method and optimization methods for estimating parameters in nonlinear ordinary differential equation
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  This study is concerned with the estimation of constant  and time-varying parameters in non-linear ordinary differential equations, which do not have analytical solutions. The estimation is done in a multi-stage method where constant and time-varying parameters are estimated in a straight sequential way from several stages. In the first stage, the model of the differential equations is converted to a regression model that includes the state variables with their derivatives and then the estimation of the state variables and their derivatives in a penalized splines method and compensating the estimations in the regression model. In the second stage, the pseudo- least squares method was used to estimate the constant parameters. In the third stage, the remaining constant parameters and the time-varying parameters are estimated by using a semi-parametric regression model. This method is compared with the optimization method, which depends on the algorithm of differential evolution algorithm to estimate unknown parameters. The comparison was made using simulations. The results showed that the results were better to the method based on the differential evolution algorithm.

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Publication Date
Mon Mar 02 2009
Journal Name
Albahith Alalami
Types, contents and scientific research methods used in public relations research at the College of Mass Communication 1989 - 2007.
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This study deals with knowing the types of research in public relations studies at the Faculty of Mass Communication for the period from 1989 to 2007 and knowing the methods that researchers used in their studies, as well as knowing the methods and tools of scientific research that were used, and whether one method or tool is used more than others, and knowing Samples used in the analysis. As well as the contents and types of this research The institutions that were subjected to the study, and the preparation of the respondents This research aims to answer the following questions:. A- What are the types of research and methods that were used in university theses that dealt with the topic? Public Relations at the Faculty of Media from 1989

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Publication Date
Fri Sep 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Comparison among pulp capping materials in: calcium ion release, pH change, solubility and water sorption (An in vitro study)
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Background: Calcium hydroxide and calcium-silicate materials used as direct pulp capping materials. The aims of this in vitro study is to compare among these materials in, the calcium ion release and pH change in soaking water after immersion of materials’ specimens in deionized water. Also Solubility and water sorption of materials’ specimens measured after soaking time. Calcium-silicate materials used were Biodentine, TheraCal and MTA Plus. Materials and methods: Four materials used in this study; Urbical lining (as control group), Biodentine, TheraCal and MTA Plus. Ten discs fabricated from each tested material, by using plastic moulds of 9 mm diameter and 1 mm thickness. Each specimen was immersed in 10 ml of d

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Publication Date
Mon Jan 01 2018
Journal Name
Journal Of The College Of Languages (jcl)
‘There is no place like home’: A Comparative Study of the Meaning of Home in The Wonderful Wizard of Oz and Peter and Wendy
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The Wonderful Wizard of Oz and Peter and Wendy present universal ideas that exist in all times, despite being written in the beginning of the 20th century. Among the most significant ones is the concept of “home”. The article discusses the essentiality of the idea of “home” where the identity of an individual shapes, and where one’s spiritual, psychological, and physical being develop. It also studies the attitudes of each protagonist towards the concept of ‘home’ based on their understanding of it and according to their gender differences. The characters in both stories tread on the path of perplexity between leaving their homes and returning to them. Peter’s world is the world of imagination while Doro

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Publication Date
Thu Dec 21 2023
Journal Name
Mathematical Modelling Of Engineering Problems
Recovering Time-Dependent Coefficients in a Two-Dimensional Parabolic Equation Using Nonlocal Overspecified Conditions via ADE Finite Difference Schemes
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Publication Date
Sat Oct 28 2023
Journal Name
Baghdad Science Journal
Impact of some environmental parameters on phytoplankton diversity in the eastern Al-Hammer marsh / southern Iraq
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Biodiversity is one of the important biological factors in determining water quality and maintaining the
ecological balance. In this study, there are 223 species of phytoplankton were identified, and they are as
follows: 88 species of Bacillariophyta and were at 44%,70 species of Chlorophyta and they were at 29 %, 39
species of Cyanophyta and they were at 16 %, 12 species of Euglenozoa and they were at 4 %, four species of
Miozoa and they were at 3 %, and, Phylum Charophyta and Ochrophyta were only eight and two species,
respectively and both of them were at 2%. The common phytoplankton recorded in the sites studied
include Nitzschia palea, Scenedesmus quadricauda, Oscillatoria princeps, and Peridinium

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Publication Date
Sat Dec 31 2016
Journal Name
Al-kindy College Medical Journal
A Comparison of Sagittal Sections of Short T1inversion Recovery and T2 Weighted Fast Spin Echo Magnetic Resonance Sequences for Detection of Multiple Sclerosis Spinal Cord Lesions
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Background: Multiple sclerosis is a chronic autoimmune inflammatory demyelinating disease of the central nervous system of unknown etiology. Different techniques and magnetic resonance image sequences are widely used and compared to each other to improve the detection of multiple sclerosis lesions in the spinal cord. Objective: To evaluate the ability of MRI short tau inversion recovery sequences in improvementof multiple sclerosis spinal cord lesion detection when compared to T2 weighted image sequences. Type of the study: A retrospective study. Methods: this study conducted from 15thAugust 2013 to 30thJune 2014 at Baghdad teaching hospital. 22 clinically definite MS patients with clinical features suggestive of spinal cord involvement,

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Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Robust estimation of multiple linear regression parameters in the presence of a problem of heterogeneity of variance and outliers values
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Often times, especially in practical applications, it is difficult to obtain data that is not tainted by a problem that may be related to the inconsistency of the variance of error or any other problem that impedes the use of the usual methods represented by the method of the ordinary least squares (OLS), To find the capabilities of the features of the multiple linear models, This is why many statisticians resort to the use of estimates by immune methods Especially with the presence of outliers, as well as the problem of error Variance instability, Two methods of horsepower were adopted, they are the robust weighted least square(RWLS)& the two-step robust weighted least square method(TSRWLS), and their performance was verifie

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Publication Date
Tue Feb 28 2023
Journal Name
Iraqi Journal Of Science
Separation and Micro Determination of Zinc(II) and Cadmium(II) in Food Samples Using Cloud Point Extraction method
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    The cloud point extraction technique has become increasingly popular in recent years for trace metal separation and preconcentration. When heated to a specific temperature, cloud point extraction utilizes the property of nonionic surfactants in aqueous solutions to generate micelles and become turbid (so-called cloud point temperature). For analytical chemists, developing a simple and selective technology for the separation and determination of metals and medicinal drugs is a critical concern. Therefore, a sensitive, accurate, and green cloud point extraction (CPE) procedure was developed for the micro-determination of metal cations like zinc (II) and cadmium (II) in food samples. Triton X–114 and 1-(4-(Phenyldiazenyl) phenyl) a

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Publication Date
Sun Nov 01 2020
Journal Name
Journal Of Engineering
Nonlinear Finite Element Analysis of RCMD Beams with Large Circular Opening Strengthened with CFRP Material
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This paper presents the non-linear finite element method to study the behavior of four reinforced rectangular concrete MD beams with web circular openings tested under two-point load. The numerical finite elements methods have been used in a much more practical way to achieve approximate solutions for more complex problems.  The ABAQUS /CAE is chosen to explore the behavior of MD beams. This paper also studies, the effect of both size and shape of the circular apertures of MD beams. The strengthening technique that used in this paper is externally strengthening using CFRP around the opening in the MD beams. The numerical results were compared to the experimental results in terms of ultimate load failure and displace

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Publication Date
Tue Jan 01 2008
Journal Name
Tikrit Journal Of Engineering Sciences
Nonlinear Analysis of CFRP- Prestressed Concrete Beams Subjected to Incremental Static Loading by Finite Elements
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