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jeasiq-1598
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
Sat Mar 01 2008
Journal Name
The Third International Conference On Mathematical Sciences
On Solvability of an Operator Equation
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Publication Date
Thu Feb 01 2007
Journal Name
No
On Solvability of an Operator Equation-
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Publication Date
Thu Feb 07 2019
Journal Name
Iraqi Journal Of Laser
Investigation of Size-dependent Nonlinearity of Ag Nano-Fluids using Self-defocusing Technique
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In this work, the effect of different particle size on the nonlinear optical properties of silver nanoparticles in de-ionized water was studied. The experimental observation of the far field diffraction patterns by CCD camera in two and three dimensions. The maximum change of nonlinear refractive index and the relative phase shift were calculated. The self-defocusing technique was used with a continuous-wave radiation from DPSS Blue laser .The wavelength is 473 nm with an output power of 270 mW. All the Ag colloids samples containing the sizes 15, 30, 50, and 70 nm of silver nanoparticles used in the study were chemically prepared. It was found that the nonlinear refractive index is a particle size dependent and of the order of 10-7 cm2/

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Publication Date
Mon Jan 01 2018
Journal Name
Ibn Al-haitham J. For Pure & Appl. Sci
Comparative Anatomical Study between Typhadomengensis and Phragmites communis
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Both of the species Typha domengensis and Phragmites communis among the most important plant endemic in flora of Iraq from monocotyledon. Due to the similarity of the two species with each other in many morphological characteristics such as the environment where they live and the form of leaves and type of leaf venation and type of stomata….ets, also both of species belong to monocots plant therefore this research work was conducted find anatomical differences that have the same as taxonomic value to help distinguishing between both species under study. Through this research, we found great importance to the anatomical characteristics which we reached by studying the roots, stems and leaves sections f

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Publication Date
Thu Jun 01 2023
Journal Name
Partial Differential Equations In Applied Mathematics
Determination of time-dependent coefficient in time fractional heat equation
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Publication Date
Sat Mar 01 2014
Journal Name
Computers & Mathematics With Applications
Simultaneous determination of time-dependent coefficients in the heat equation
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Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Evaluation of Common Stocks Using The Fama-French Five Factor Model An Applied Study in The Iraq Stock Exchange
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     The process of stocks evaluating considered as a one of challenges for the financial analysis, since the evaluating focuses on define the current value for the cash flows which the shareholders expected to have. Due to the importance of this subject, the current research aims to choose Fama & French five factors Model to evaluate the common stocks to define the Model accuracy in Fama& French for 2014. It has been used factors of volume, book value to market value, Profitability and investment, in addition to Beta coefficient which used in capital assets pricing Model as a scale for Fama & French five factors Model. The research sample included 11 banks listed in Iraq stock market which have me

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Publication Date
Wed Apr 25 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
On Estimating the Survival Function for the Patients Suffer from the Lung Cancer Disease
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          In this paper, the survival function has been estimated for the patients with lung cancer using different parametric estimation methods depending on sample for completing real data which explain the period of survival for patients who were ill with the lung cancer based on the diagnosis of disease or the entire of patients in a hospital for a time of two years (starting with 2012 to the end of 2013). Comparisons between the mentioned estimation methods has been performed using statistical indicator mean squares error, concluding that the estimation of the survival function for the lung cancer by using pre-test singles stage shrinkage estimator method was the best   . <

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Publication Date
Sun Jan 01 2012
Journal Name
Journal Of The College Of Languages (jcl)
LOS ENUNCIADOS INTERROGATIVOS DIRECTOS: ESTUDIO MORFOLOGLCO CONTRASTIVO ENTRE EL ESPANOL Y EL ARABE
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Los enunciados interrogativos desempeñan un papel de sumo interés en el habla del ser humano en todo el mundo, además de la gran importancia que desempeñan sus distintos enunciados y partículas en abreviar las oraciones y hacer llegar a nuestro interlocutor nuestra intención con pocas palabras, por eso a través de esta investigación vamos a enfocar la luz sobre uno de sus tipos fundamentales "los enunciados interrogativos directos", a través de un estudio morfológico contrastivo entre el árabe y el español,  este fue el principal motivo para elegir este tema.

A pesar de que los enunciados interrogativos directos aparentemente no ofrecen mucha dificultad, pero dominar a dicho tipo de enunciados con

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Publication Date
Wed Nov 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
strong criminal capabilities، Using simulation .
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The penalized least square method is a popular method to deal with high dimensional data ,where  the number of explanatory variables is large than the sample size . The properties of  penalized least square method are given high prediction accuracy and making estimation and variables selection

 At once. The penalized least square method gives a sparse model ,that meaning a model with small variables so that can be interpreted easily .The penalized least square is not robust ,that means very sensitive to the presence of outlying observation , to deal with this problem, we can used a robust loss function to get the robust penalized least square method ,and get robust penalized estimator and

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