Archive by Category "ticma2022"

^{1, a)} Rizgar H. Salih and Bashdar M. Mohammed ^{2, b)}

^1,2 Department of Mathematics, College of Basic Education,

University of Raparin, Raniyah, Kurdistan Region – Iraq.

^a)rizgar.salih@uor.edu.krd

^b)bashdar.mahmoodmuhamad@uor.edu.krd

This paper is devoted to studying the stability of the unique equilibrium point and the occurrence of the Hopf bifurcation as well as limit cycles of a three-dimensional chaotic system. We characterize the parameters for which a Hopf equilibrium point takes place at the equilibrium point. In addition, the system has only one equilibrium point which is E_0=(0,0,0). It was proved that E_0 is asymptotically stable and unstable when α<(-13)/7 and α>(-13)/7, respectively. Moreover, for studying the cyclicity of the system, two techniques are used which are dynamics on the center manifold and Liapunov quantities. It was shown that at most two limit cycles can be bifurcated from the origin. All the results presented in this paper have been verified by a program via Maple software.

Halgwrd Mohammed Darwesh^{1, a} And Shagull Hossein Mahmood^{2, b}

^1,2 Department of Mathematics, College of Science, University of Sulaimani,

46001 Sulaimani, Kurdistan Region, Iraq

^a) halgwrd.darwesh@univsul.edu.iq
^b) shagull.mahmmod@univsul.edu.iq

In this 𝑤𝑜𝑟𝑘, we study and define two new concepts of functions named  and  functions by using the concepts of  and ϲ𝑙𝑜𝑠𝑒𝑑 sets. The concept of  function strictly located between both the concepts of  and  functions. We obtain a few properties of these functions, however, the connections between them are examined.

Abdulghafoor Jasim. Salim¹ Ali A. Asmael²

^1,2Department of Mathematics, college of computer science and Mathematics, University of Mosul.

^1,drabdul_salim@uomosul.edu.iq 

2ali.20csp132@student.uomosul.edu.iq

Hajir Hayder Abdullah^1,a) and Nada Yassen Kasm Yahya^2,b)

¹Department of Mathematics, College of Education for Pure Science, University of Mosul, Mosul, Iraq

²Department of Mathematics, College of Education for Pure Science, University of Mosul, Mosul, Iraq

^a) 20esp13@student.uomosul.edu.iq

^b) drnadaqasim1@gmail.com, drnadaqasim3@uomosul.edu.iq

Zhian M. Mahmood^1,a) and Nejmaddin A.Sulaiman^1,b)
1Department of Mathematics, College of Education, Salahaddin University, Erbil, 44001, Iraq

^a) m.mahmood@su.edu.krd
^b) nejmaddin.sulaiman@su.edu.krd

Pishtiwan O. Sabir^{1, a)} and Aram N. Qadir^{2, b)}

¹⁾ Department of Mathematics, College of Science, University of Sulaimani, Sulaymaniyah 46001, Iraq.

²⁾ Department of Mathematics, College of Education, University of Garmian, Kalar 46021, Iraq.

^a) pishtiwan.sabir@univsul.edu.iq