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The food web prey-predator model with toxin
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Publication Date
Thu Apr 01 2021
Journal Name
Chaos, Solitons & Fractals
Modeling and analysis of an SI1I2R epidemic model with nonlinear incidence and general recovery functions of I1
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In this paper, we established a mathematical model of an SI1I2R epidemic disease with saturated incidence and general recovery functions of the first disease I1. Considering the basic reproduction number, we obtained conditions for both disease-free and co-existing cases. The equilibrium points local stability is verified by using the Routh-Hurwitz criterion, while for the global stability, we used a suitable Lyapunov function to analyze the endemic spread of the positive equilibrium point. Moreover, we carried out the local bifurcation around both equilibrium points (disease-free and co-existing), where we obtained that the disease-free equilibrium point undergoes a transcritical bifurcation. We conduct numerical simulations that suppo

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Publication Date
Tue Oct 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Comparison Robust M Estimate With Cubic Smoothing Splines For Time-Varying Coefficient Model For Balance Longitudinal Data
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In this research، a comparison has been made between the robust estimators of (M) for the Cubic Smoothing Splines technique، to avoid the problem of abnormality in data or contamination of error، and the traditional estimation method of Cubic Smoothing Splines technique by using two criteria of differentiation which are (MADE، WASE) for different sample sizes and disparity levels to estimate the chronologically different coefficients functions for the balanced longitudinal data which are characterized by observations obtained through (n) from the independent subjects، each one of them is measured repeatedly by group of  specific time points (m)،since the frequent measurements within the subjects are almost connected an

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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
A Modified Approach by Using Prediction to Build a Best Threshold in ARX Model with Practical Application
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The proposal of nonlinear models is one of the most important methods in time series analysis, which has a wide potential for predicting various phenomena, including physical, engineering and economic, by studying the characteristics of random disturbances in order to arrive at accurate predictions.

In this, the autoregressive model with exogenous variable was built using a threshold as the first method, using two proposed approaches that were used to determine the best cutting point of [the predictability forward (forecasting) and the predictability in the time series (prediction), through the threshold point indicator]. B-J seasonal models are used as a second method based on the principle of the two proposed approaches in dete

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Publication Date
Mon Jun 01 2015
Journal Name
Int. J. Adv. Appl. Math. Andmech.
The effect of external source of disease on the epidemic model
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Publication Date
Tue Jun 28 2022
Journal Name
Journal Of Physical Education
تأثير الرحلات المعرفية عبر الانترنيت (WEB QUEST) في التحصيل المعرفي بكرة اليد لدى طالبات المرحلة الثانية في كلية التربية البدنية وعلوم الرياضة – جامعة بغداد
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هدف البحث إلى تصميم برنامج الكتروني للرحلات المعرفية عبر الانترنيت (web quest) المصاحب لمنهج تعليمي معد للدروس العملية بكرة اليد لطالبات المرحلة الثانية، والتعرف على تأثيره في التحصيل المعرفي بكرة اليد لديهن، وأُعتمد المنهج التجريبي بتصميم المجموعتين التجريبيتين والمجموعة الضابطة على عينة من طالبات المرحلة الثانية في كلية التربية البدنية وعلوم الرياضة/جامعة بغداد للعام الدراسي (2021- 2022)، البالغ عددهن (60) طا

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Publication Date
Tue Jun 28 2022
Journal Name
Journal Of Physical Education
تأثير الرحلات المعرفية عبر الانترنيت (WEB QUEST) في التحصيل المعرفي بكرة اليد لدى طالبات المرحلة الثانية في كلية التربية البدنية وعلوم الرياضة – جامعة بغداد
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هدف البحث إلى تصميم برنامج الكتروني للرحلات المعرفية عبر الانترنيت (web quest) المصاحب لمنهج تعليمي معد للدروس العملية بكرة اليد لطالبات المرحلة الثانية، والتعرف على تأثيره في التحصيل المعرفي بكرة اليد لديهن، وأُعتمد المنهج التجريبي بتصميم المجموعتين التجريبيتين والمجموعة الضابطة على عينة من طالبات المرحلة الثانية في كلية التربية البدنية وعلوم الرياضة/جامعة بغداد للعام الدراسي (2021- 2022)، البالغ عددهن (60) طا

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Publication Date
Sat Jan 02 2021
Journal Name
The International Journal Of Nonlinear Analysis And Application
Atan regularized for the high dimensional Poisson regression model
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Variable selection in Poisson regression with high dimensional data has been widely used in recent years. we proposed in this paper using a penalty function that depends on a function named a penalty. An Atan estimator was compared with Lasso and adaptive lasso. A simulation and application show that an Atan estimator has the advantage in the estimation of coefficient and variables selection.

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Publication Date
Fri Jul 23 2021
Journal Name
International Journal Of Nonlinear Analysis And Applications
On the dynamical behavior of an eco-epidemiological model
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The aim of this article is to study the dynamical behavior of an eco-epidemiological model. A prey-predator model comprising infectious disease in prey species and stage structure in predator species is suggested and studied. Presumed that the prey species growing logistically in the absence of predator and the ferocity process happened by Lotka-Volterra functional response. The existence, uniqueness, and boundedness of the solution of the model are investigated. The stability constraints of all equilibrium points are determined. The constraints of persistence of the model are established. The local bifurcation near every equilibrium point is analyzed. The global dynamics of the model are investigated numerically and confronted with the obt

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Publication Date
Fri Jun 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
"RUF procedures forgetting the best subset linear regression model"
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The purpose behind building the linear regression model is to describe the real linear relation between any explanatory variable in the model and the dependent one, on the basis of the fact that the dependent variable is a linear function of the explanatory variables and one can use it for prediction and control. This purpose does not cometrue without getting significant, stable and reasonable estimatros for the parameters of the model, specifically regression-coefficients. The researcher found that "RUF" the criterian that he had suggested accurate and sufficient to accomplish that purpose when multicollinearity exists provided that the adequate model that satisfies the standard assumpitions of the error-term can be assigned. It

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Publication Date
Tue Dec 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Study the Axail Dispersion Model in Ion Exchange Column
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A mathematical model is developed which predicates the performance of cylindrical ion exchange bed involving comparing of axial dispersion model for cation exchange column with different assumption, this model permits the performance to predicate the residence time within the bed with the variance, axial dispersion and Pecklet No. to indicated deviation from plug flow model.

      Two type of systems are chosen for positive ions first with divalent ions (Ca+2) to exchange with resin of Na+1form used as application in  water softener units and second with monovalent ions (Na+1) to exchange with resin of H+1 form used as application in deionize water units &n

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