Oscillation criteria are obtained for all solutions of the first-order linear delay differential equations with positive and negative coefficients where we established some sufficient conditions so that every solution of (1.1) oscillate. This paper generalized the results in [11]. Some examples are considered to illustrate our main results.
The majority of real-world problems involve not only finding the optimal solution, but also this solution must satisfy one or more constraints. Differential evolution (DE) algorithm with constraints handling has been proposed to solve one of the most fundamental problems in cellular network design. This proposed method has been applied to solve the radio network planning (RNP) in the forthcoming 5G Long Term Evolution (5G LTE) wireless cellular network, that satisfies both deployment cost and energy savings by reducing the number of deployed micro base stations (BSs) in an area of interest. Practically, this has been implemented using constrained strategy that must guarantee good coverage for the users as well. Three differential evolution
... Show MoreThe current study aims to develop a teaching design in accordance with cluster thinking strategies and explore the effect of this teaching design on students’ achievement in science. To this end, the null hypothesis was adopted: there is no statistically significant difference at the level of (0, 05) between experimental group who adopted the teaching design in learning science and control group who follow the traditional method in learning the same subject. To test the null hypothesis, total of (74) students from Al-Alaama Hussain Mahfooth intermediate school were selected intentionally for the academic year 2016-2017. The sample divided into two equal groups when all the variables (age, prior achievement of science,
... Show MoreThis research is concerned with the study of (the aesthetic of constructive relations in linear composition) with what distinguished Arabic calligraphy through the style and artistic method in its construction, and the specifications it carries that enabled it to pay attention to building formations to achieve in its total linear ranges aesthetic values and relationships. Through the research, the models and the exploratory study that he obtained, the researcher was able to raise the research problem in the first chapter according to the following question: What is the aesthetic of constructive relations in linear formation?
The importance of the research in achieving the aesthetics of the formations, which is a wide field according t
This study aims to know the relationship between the birth order and lifestyles among a sample of adolescent students. The sample of the study consisted of (200) students selected from the governmental schools in the Directorate of Education of Qabatiya, in the second semester of the academic year 2020/2021. The results of the study have revealed that the most common lifestyles among the sample of the study are represented by: (the belonging) style, (the submissive) style, (the avenger) style, (the pampered) style, respectively. The study has also found that there are statistically significant differences in the lifestyles of: (the victim, the domineering, the avenger, and the harmful) which are ascribed to the gender variable. Mor
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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 es
... Show MoreThis work presents a computer studying to simulate the charging process of a dust grain immersed in plasma with negative ions. The study based on the discrete charging model. The model was developed to take into account the effect of negative ions on charging process of dust grain.
The model was translated to a numerical calculation by using computer programs. The program of model has been written with FORTRAN programming language to calculate the charging process for a dust particle in plasma with negative ion, the time distribution of a dust charge, number charge equilibrium and charging time for different value of ηe (ratio of number density of electron to number density of positive ion).
During a survey on the helminthic parasites of three species of turtles in the north part of Iraq, five species of nematodes were recorded for the first time in Iraq. They were all found in the intestine. These are, Camallanus microcephalus (Dujardin, 1845) recorvered from the turtle Clemmys caspica; Spironoura japonensis (Yamaguti, 1935) from Triopyx eup¬hraticus and Angusticaecum holopterum (Rudolphi, 1819), and Tachygonetria nicollei (Seurat, 1918) from the turtle Testudo graeca. All of the localities and hosts are newly recorded in Iraq.
The family Pholcidae represented by the species Artema doriae )Thorell, 1881) is recorded in Iraq for the first time.So far, 23 families of spiders have been recorded in Iraq.
In this paper, we add a new family and a description of a species belonging to this family in the checklist of Iraqi spider fauna.