JPRM-Vol. 20 (2024), Issue 1, pp. 65 – 80
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Hamida Hamioud, Nouressadat Touafek, Imane Dekkar, Mohammed B. Almatrafi
Abstract: Consider the following general three dimensional system of difference equations
\begin{cases}
x_{n+1}=f^{-1}\left(\frac{g(y_{n} )g(y_{n-1} )(f(x_{n-1} ))^{p}}{f(x_{n} )[a_{n} (g(y_{n-2} ))^{q} +b_{n} g(y_{n} )g(y_{n-1} )]}\right),\\
y_{n+1}=g^{-1} \ \left(\frac{h(z_{n} )h(z_{n−1} )(g(y_{n−1} ))^{q}}{g(y_{n} )[c_{n} (h(z_{n−2} ))^{r} +d_{n} h(z_{n} )h(z_{n−1} )]}\right),\\
\ z_{n+1} =h^{−1} \ \ \left(\frac{f(x_{n} )f(x_{n−1} )(h(z_{n−1} ))^{r}}{h(z_{n} )[s_{n} (f(x_{n−2} ))^{p} +t_{n} f(x_{n} )f(x_{n−1} )]}\right),\end{cases}
where 𝑛∈ℕ0,𝑝,𝑞,𝑟∈ℕ,𝑓,𝑔,ℎ :D→ℝ are continuous one-to-one functions on D⊆ℝ, the coefficients (𝑎𝑛)𝑛∈ℕ0,(𝑏𝑛)𝑛∈ℕ0(𝑐𝑛)𝑛∈ℕ0,(𝑑𝑛)𝑛∈ℕ0,(𝑠𝑛)𝑛∈ℕ0,(𝑡𝑛)𝑛∈ℕ0 are non-zero real numbers and the initial values 𝑥−𝑖,𝑦−𝑖,𝑧−𝑖,𝑖=0,1,2, are real numbers. We will give explicit formulas for well-defined solutions of the aforementioned system in both variable and constant cases of the coefficients. As an application, we will deduce the formulas of the solutions of the particular system obtained from the general one by taking 𝑓(𝑥)=𝑔(𝑥)=ℎ(𝑥)=𝑥.
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JPRM-Vol. 20 (2024), Issue 1, pp. 58 – 64
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Muhammad Imran Qureshi, Zill e Shams, Rukhsar Zireen, Sana Saeed
Abstract: The resolving set for connected graphs has become one of the most important concept due to its applicability in networking, robotics and computer sciences. Let G be a simple and connected graph, an ordered-subset B of V (G) is called resolving set of G, if every distinct vertex of G have different metric code w.r.t B. Smallest resolving set of G is known as basis of G and size of basis set is called as metric dimension(MD) of graph G. A resolving set B′ of G is known as fault-tolerant resolving set(FTRS), ifB′\{v} is also resolving set, ∀ v ϵ B′. Such set B′ with smallest size is termed as fault-tolerant metric basis and the cardinality of this set is called fault-tolerant metric dimension(FTMD) of graph G. A FTMD set B′ for which the system failure at vertex location v of any station still provide us a resolving set. In this article, we have provided the MD and FTMD for triangular benzenoid system and hourglass benzenoid system.
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JPRM-Vol. 20 (2024), Issue 1, pp. 43 – 57
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Derbouche Assia, Hamri Nasr-Eddine, Laouira Widad
Abstract: The forced SIR system’s synchronization is the main subject of this study. Through the use of several control techniques, including active control (AC), active backstepping control (ABC), adaptive control (AdC), and sliding mode control (SMC). We redesigned the three-dimensional system to be autonomous and made it four-dimensional to ease numerical computations. The system’s phase portrait, Lyapunov exponent graph, and bifurcation diagram are used to analyze its dynamic properties through numerical simulation. The effectiveness of the AC, SMC, ABC, and AdC approaches is examined using dynamical error and necessary control inputs. By contrasting the integral square error with the required control energy measurements, the best control for synchronization is found.
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