Preferred Language
Articles
/
2RfUTo8BVTCNdQwCC2ok
Stability and Bifurcation of a Prey-Predator-Scavenger Model in the Existence of Toxicant and Harvesting
...Show More Authors

In this paper a prey-predator-scavenger food web model is proposed and studied. It is assumed that the model considered the effect of harvesting and all the species are infected by some toxicants released by some other species. The stability analysis of all possible equilibrium points is discussed. The persistence conditions of the system are established. The occurrence of local bifurcation around the equilibrium points is investigated. Numerical simulation is used and the obtained solution curves are drawn to illustrate the results of the model. Finally, the nonexistence of periodic dynamics is discussed analytically as well as numerically.

Scopus Clarivate Crossref
Publication Date
Sun Aug 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of the performance of some r- (k,d) class estimators with the (PCTP) estimator that used in estimating the general linear regression model in the presence of autocorrelation and multicollinearity problems at the same time "
...Show More Authors

In the analysis of multiple linear regression, the problem of multicollinearity and auto-correlation drew the attention of many researchers, and given the appearance of these two problems together and their bad effect on the estimation, some of the researchers found new methods to address these two problems together at the same time. In this research a comparison for the performance of the Principal Components Two Parameter estimator (PCTP) and The (r-k) class estimator and the r-(k,d) class estimator by conducting a simulation study and through the results and under the mean square error (MSE) criterion to find the best way to address the two problems together. The results showed that the r-(k,d) class estimator is the best esti

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of the method of partial least squares and the algorithm of singular values decomposion to estimate the parameters of the logistic regression model in the case of the problem of linear multiplicity by using the simulation
...Show More Authors

The logistic regression model is an important statistical model showing the relationship between the binary variable and the explanatory variables.                                                        The large number of explanations that are usually used to illustrate the response led to the emergence of the problem of linear multiplicity between the explanatory variables that make estimating the parameters of the model not accurate.    

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Use Simulation To Differentiate Between Some Modern Methods To the Model GM(1,1) To Find Missing Values And Estimate Parameters With A Practical Application
...Show More Authors

Abstract

       The grey system model GM(1,1) is the model of the prediction of the time series and the basis of the grey theory. This research presents the methods for estimating parameters of the grey model GM(1,1) is the accumulative method (ACC), the exponential method (EXP), modified exponential method (Mod EXP) and the Particle Swarm Optimization method (PSO). These methods were compared based on the Mean square error (MSE) and the Mean Absolute percentage error (MAPE) as a basis comparator and the simulation method was adopted for the best of the four methods, The best method was obtained and then applied to real data. This data represents the consumption rate of two types of oils a he

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 01 2018
Journal Name
Journal Of Educational And Psychological Researches
The effectiveness of Barman model in acquiring the historical concepts among fourth-grade literary students
...Show More Authors

The researcher attempts to examine Barman model in acquiring the historical concepts among fourth-grade students at literary classrooms. To this end, the researcher held the null hypothesis, there is no significant difference between the experimental groups who was taught based on Barman model and the control group that taught based on the traditional method in acquiring the historical concepts on the post-test. To testify the effectiveness of Barman model, the researcher administered a questionnaire included (60) items on bunch of female-students who were selected from al-khamaeal preparatory school in al-hurriyah district in Baghdad. The author utilized different statistical tools to analyze the collected data.    &

... Show More
View Publication Preview PDF
Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Educational And Psychological Researches
The effectiveness of Barman model in acquiring the historical concepts among fourth-grade literary students
...Show More Authors

The researcher attempts to examine Barman model in acquiring the historical concepts among fourth-grade students at literary classrooms. To this end, the researcher held the null hypothesis, there is no significant difference between the experimental groups who was taught based on Barman model and the control group that taught based on the traditional method in acquiring the historical concepts on the post-test. To testify the effectiveness of Barman model, the researcher administered a questionnaire included (60) items on bunch of female-students who were selected from al-khamaeal preparatory school in al-hurriyah district in Baghdad. The author utilized different statistical tools to analyze the collected data.    &

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
The role of strategic memory in the successful use of the COSO model for auditing human resource management
...Show More Authors

The main purpose of the research is to diagnose the importance of the role that strategic memory plays with its three variables (content, structure, and processes) in helping the human resource department to use the COSO model with its five components (culture and governance, strategy and objectives, performance, communications and information, and feedback) in auditing activities and tasks Her own. As the research problem emphasized the existence of a lack of cognitive perception, of the importance of strategic memory, and the investment of its components in the rationalization of the application of the COSO model. and therefore it can be emphasized that the importance of the research is to provide treatments for problems relate

... Show More
View Publication Preview PDF
Crossref
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
...Show More Authors

Publication Date
Mon Mar 15 2021
Journal Name
Al-academy
Semiotics of Musical Sign in Iraqi Pantomime Show (Ahriman) as a Model: علي عدي صاحب-شيماء حسين طاهر
...Show More Authors

The musical sign was associated with the first appearances of acting that are based on human gestures and expressive and silent movements, and they contributed in accentuating and clarifying these gestures and explain their meanings and indications, and they remained with them until these gestures turned into artistic theatrical shows so that the musical sign would have many functions and constitute the main pillars for this kind of show.
The musical sign is a language not much different than the human language in the semiotic analysis. There has been an increased interest in it and its use in the mime shows by the graduates who realized its necessity and significance in the pantomime show intellectually, artistically and aesthetical

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Jan 14 2020
Journal Name
College Of Islamic Sciences
(Social Reform in the Light of Modern Islamic Thought (Malik bin Nabi model
...Show More Authors

Social reform is the main pillar of the organization of societies. Therefore, all religions and theories were directed to focus on this aspect as the most important element for the development of economic and cultural development. In addition to the analysis and application of the Islamic Sharia, he did not present a theory, but offered real solutions and remedies to the crises in our Arab and Islamic societies alike, despite the criticism directed at him. Z his opinions.<

... Show More
View Publication
Publication Date
Sun Mar 01 2020
Journal Name
Iraqi Journal Of Physics
Chaotic features of energy spectrum in 68Ge Nucleus Using the Nuclear Shell Model
...Show More Authors

   Chaotic features of nuclear energy spectrum in 68Ge nucleus are investigated by nuclear shell model. The energies are calculated through doing shell model calculations employing the OXBASH computer code with effective interaction of F5PVH. The 68Ge nucleus is supposed to have an inert core of 56Ni with 12 nucleons (4 protons and 8 neutrons) move in the f5p-model space ( and ). The nuclear level density of considered classes of states is seen to have a Gaussian form, which is in accord with the prediction of other theoretical studies. The statistical fluctuations of the energy spectrum (the level spacing P(s) and the Dyson-Mehta (or statistics) are well described by the Gaussian orthogonal ens

... Show More
View Publication Preview PDF
Crossref