Preferred Language
Articles
/
ijp-726
Simulation of Small Radio Telescope Antenna Parameters at Frequency of 1.42 GHz
...Show More Authors

The paper presents an overview of theoretical aspects of small radio telescope antenna parameters. The basic parameters include antenna beamwidth, antenna gain, aperture efficiency, and antenna temperature. These parameters should be carefully studied since they have vital effects on astronomical radio observations. The simulations of antenna parameters were carried out to assess the capability and the efficiency of small radio telescopes to observe a point source at a specific frequency. Two-dimensional numerical simulations of a uniform circular aperture antenna are implemented at different radii. The small diameter values are chosen to be varied between (1-10) m. This study focuses on a small radio telescope with a diameter of 3 m since this telescope is very common in the world. The simulated results of this study illustrated that the power pattern of a 3 m antenna has a half-power beamwidth of approximately 5 degrees. Also, the maximum peak antenna temperature is estimated to be more than 3000 K. All of these results were in good agreement with observations of the neutral hydrogen spectral line at the frequency of 1.42 GHz using a small radio telescope.

Crossref
View Publication Preview PDF
Quick Preview PDF
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 May 18 2023
Journal Name
Journal Of Engineering
Optimal Dimensions of Small Hydraulic Structure Cutoffs Using Coupled Genetic Algorithm and ANN Model
...Show More Authors

A genetic algorithm model coupled with artificial neural network model was developed to find the optimal values of upstream, downstream cutoff lengths, length of floor and length of downstream protection required for a hydraulic structure. These were obtained for a given maximum difference head, depth of impervious layer and degree of anisotropy. The objective function to be minimized was the cost function with relative cost coefficients for the different dimensions obtained. Constraints used were those that satisfy a factor of safety of 2 against uplift pressure failure and 3 against piping failure.
Different cases reaching 1200 were modeled and analyzed using geo-studio modeling, with different values of input variables. The soil wa

... Show More
View Publication Preview PDF
Crossref (10)
Crossref
Publication Date
Tue Jul 25 2017
Journal Name
J. Entomol. Zool. Studies
Histological and histochemical observations of the small Intestine in the indigenous Gazelle (Gazella subgutturosa)
...Show More Authors

LO Hamza, NA Al-Mansor, J. Entomol. Zool. Studies, 2017 - Cited by 14

View Publication
Publication Date
Thu Jan 01 2015
Journal Name
Mediterranean Journal Of Social Sciences
How are the Performance of Small Businesses Influenced by HRM Practices and Governmental Support?
...Show More Authors

Human resources have been regarded as the most important asset for any organization because of its essential part in achieving the sustainable competitive advantage and survival. Managing human resources is very challenging and requires an effective bundle of practices that contribute to attaining the organizational goals. This study tries to confirm the importance of HRM practices in small businesses which came to play a vital role in the economies of the world, through clarifying the influence of HRM practices on the organizational performance, using a mediating variable (employees’ outcomes). Also the study attempts to highlight the key role of governmental support from view point of small businesses, through verifying the significant

... Show More
View Publication Preview PDF
Scopus (10)
Crossref (2)
Scopus Crossref
Publication Date
Wed Nov 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
strong criminal capabilities، Using simulation .
...Show More Authors

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

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Feb 01 2021
Journal Name
Journal Of Physics: Conference Series
Hyper Fuzzy AT-ideals of AT-algebra
...Show More Authors
Abstract<p>The aim of this paper is to introduce the notion of hyper fuzzy AT-ideals on hyper AT-algebra. Also, hyper fuzzy AT-subalgebras and fuzzy hyper AT-ideal of hyper AT-algebras are studied. We study on the fuzzy theory of hyper AT-subalgebras and hyper AT-ideal of hyper AT-algebras. Furthermore, the fuzzy set theory of the (weak, strong, s-weak) hyper fuzzy ATideals in hyper AT-algebras are applied and the relations among them are obtained.</p>
View Publication
Scopus (2)
Scopus Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Matec Web Of Conferences
Carbon-13 Characterization and Modelling for Temperature Measurement-Based Proton Frequency
...Show More Authors

The physical substance at high energy level with specific circumstances; tend to behave harsh and complicated, meanwhile, sustaining equilibrium or non-equilibrium thermodynamic of the system. Measurement of the temperature by ordinary techniques in these cases is not applicable at all. Likewise, there is a need to apply mathematical models in numerous critical applications to measure the temperature accurately at an atomic level of the matter. Those mathematical models follow statistical rules with different distribution approaches of quantities energy of the system. However, these approaches have functional effects at microscopic and macroscopic levels of that system. Therefore, this research study represents an innovative of a wi

... Show More
View Publication
Scopus Crossref
Publication Date
Tue Nov 01 2011
Journal Name
International Journal Of Mechanical And Materials Engineering
Simulation and design optimization of magneto rheological control valve
...Show More Authors

Magneto-rheological (MR) Valve is one of the devices generally used to control the speed of Hydraulic actuator using MR fluid. The performance of valve depends on the magnetic circuit design. Present study deals with a new design of MR valve. The finite element analysis is carried out on this valve to optimize its design. The design of the magnetic circuit is accomplished by magnetic finite element software such as Finite Element Method Magnetic (FEMM). The Model dimensions of MR valve, material properties and the circuit properties of valve coil are taken into account. The results of analysis are presented in terms of magnetic strength and magnetic flux density. The valve can be operated with variable flow rate by varying the current. It i

... Show More
View Publication Preview PDF
Scopus (2)
Scopus
Publication Date
Thu Mar 14 2019
Journal Name
Al-khwarizmi Engineering Journal
Creeping Gait Analysis and Simulation of a Quadruped Robot
...Show More Authors

A quadruped (four-legged) robot locomotion has the potential ability for using in different applications such as walking over soft and rough terrains and to grantee the mobility and flexibility. In general, quadruped robots have three main periodic gaits:  creeping gait, running gait and galloping gait. The main problem of the quadruped robot during walking is the needing to be statically stable for slow gaits such as creeping gait. The statically stable walking as a condition depends on the stability margins that calculated particularly for this gait. In this paper, the creeping gait sequence analysis of each leg step during the swing and fixed phases has been carried out. The calculation of the minimum stability margins depends up

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Sun Feb 24 2019
Journal Name
Iraqi Journal Of Physics
Newtonian and modified newtonian gravitational simulation of spiral galaxies
...Show More Authors

One of the most powerful tools for any stellar dynamics is the N-body simulation. In an N-body simulation the motion of N particles is followed under their mutual gravitational attraction. In this paper the gravitational N-body simulation is described to investigate Newtonian and non- Newtonian (modified Newtonian dynamics) interaction between the stars of spiral galaxies. It is shown that standard Newtonian interaction requires dark matter to produce the flat rotational curves of the systems under consideration, while modified Newtonian dynamics (MOND) theorem provides a flat rotational curve and gives a good agreement with the observed rotation cu

... Show More
View Publication Preview PDF
Crossref