Afrika Matematika最新文献

In this paper coefficient bounds and Fekete-Szegő inequalities are obtained for the classes of analytic functions ({{mathcal {S}}}_lambda ^{nu , n}(eta , [phi ]), {{mathcal {C}}}_lambda ^{nu , n}(eta , [phi ], [psi ])), ({{mathcal {R}}}_lambda ^{nu , n}(eta , gamma , [phi ], [psi ])) introduced in a recent work. Some of the main results generalize previously known results.

This paper bridges synthetic and classical differential geometry by investigating the metrizability and dynamics of Weil bundles. For a smooth, compact manifold (M) and a Weil algebra (textbf{A}), we prove that the manifold (M^textbf{A}) of (textbf{A})-points admits a canonical, weighted metric (mathfrak {d}_w) that encodes both base-manifold geometry and infinitesimal deformations. Our approach relies on constructions and methods of local and global analysis. Key results include: (1). Metrization: (mathfrak {d}_w) induces a complete metric topology on (M^textbf{A}). (2). Path Lifting: Curves lift from (M) to (M^textbf{A}) while preserving topological invariants. (3). Dynamics: Fixed-point theorems for diffeomorphisms on (M^textbf{A}) connected to stability analysis. (4). Topological Equivalence: (H^*(M^textbf{A}) cong H^*(M)) and (pi _*(M^textbf{A}) cong pi _*(M)).

In algebraic semigroups when we deal with classical sets it is not necessary every (rho)-ideal is (overline{rho })-ideal. Therefore, in this work it is proved that possible for their extension in non-classical sets like fuzzy sets and bipolar fuzzy sets with their new forms in algebraic semigroups. Moreover, a new structure of bipolar fuzzy ideals is shown. The new connotations like (rho)-semigroup, (rho)-subsemigroup, (rho)-ideal semigroup, (overline{rho })-ideal semigroup, (rho)-semigroup homomorphism are investigated. Also, some connotations of fuzzy logic, like fuzzy (rho)-subsemigroup, fuzzy (rho)-ideal semigroup, fuzzy (overline{rho })-ideal semigroup, bipolar fuzzy (rho)-subsemigroup, bipolar fuzzy (rho)-ideal semigroup and bipolar fuzzy (overline{rho })-ideal semigroup are found. Furthermore, some basic characterizations of our connotations are studied and discussed. In this paper, the (rho)-semigroup homomorphism image, translations and the product characteristics of bipolar fuzzy (rho)/(overline{rho })-ideals semigroups are studied their applications.

A combination of a rough set and a soft set is a powerful tool for dealing with uncertainty. The goal of this work is to study the idea of roughness in comparison to soft sets over the cubic dihedral group. On another side, by using the normal soft cubic dihedral groups that correspond to each parameter are inserted. Some fundamental results about these classes over groups are addressed using examples. Furthermore, using group homomorphism based on the soft (perimage/ image) of a normal cubic dihedral group in a soft setting, this work demonstrates a relationship between our classes.

The target of this work is to analyze a one-dimensional thermoelastic porous system under the action of Lord–Shulman heat conduction theory. From a second spectrum perspective, the well-posedness is studied using Faedo–Galerkin approximation, then the exponential stability is established without any assumptions on parameters.

The nonlinear vibrations of a cantilever beam model and the dynamic analysis of several resonances (primary and secondary) controlled by the proportional-derivative (PD) control are studied and discussed. The multiple time-scales method is applied to solve the dynamical system of the cantilever beam where the response curves before and after control are obtained. Through these curves, the stability of the beam’s oscillatory behavior is tested under the effect of different physical parameters. The beam suffers from high vibration amplitudes in each resonance case, especially in the superharmonic and subharmonic resonance cases. Besides the nontrivial amplitude of oscillation, a trivial one appears in some secondary resonance cases. Tuning the control gains can lead to acceptable vibration mitigation levels besides approaching the trivial amplitude in some resonance cases. Accordingly, the analytical and numerical results are compared before and after control to validate the control law.

The goal of this note is to give a positive answer to the problem 4.11 in [Almost BS-compact operators and domination problem, Mediterr. J. Math. 18, 258 (2021)]. More precisely, we proved that if a positive operator R on a Banach lattice E is dominated by an almost BS-compact operator (T: E rightarrow E), then (R^2) is almost BS-compact.

Each irreducible representation of the motion group of the plane has a unique maximal inductive algebra, and it is self-adjoint.

Wind energy claims a positive image globally; therefore, accurate modelling of wind direction at generation sites accurately can enhance the potential of this green energy source. The uncertain nature of wind direction can be modelled through probability distributions; in this paper, we propose a flexible yet simple distribution, namely the Power-Cardioid distribution, as an alternative and implementable candidate to model wind direction. After discussing some characteristics, the performance of the Power-Cardioid distribution is evaluated via a simulation study and applied to datasets of two wind farms in South Africa. The numerical results demonstrate that this distribution is a promising and exciting new candidate compared to well-known models within circular statistics.

In this paper, we acquaint universally prestarlike generalized functions of order (vartheta ) with (vartheta le 1) associated with generalized telephone numbers and we get coefficient bounds for ( fin mathscr {R} _{vartheta }^{u}(Psi )) and also for ( f^{-1} in mathscr {R} _{vartheta }^{u}(Psi )) which has not been discussed earlier. Further we obtain the Fekete-Szegö functional for the class of universally prestarlike functions and applications to certain probability distribution based on convolution product for such functions.