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Open Access
Article
Publication date: 18 January 2024

Hani Abidi, Rim Amami, Roger Pettersson and Chiraz Trabelsi

The main motivation of this paper is to present  the Yosida approximation of a semi-linear backward stochastic differential equation in infinite dimension. Under suitable…

Abstract

Purpose

The main motivation of this paper is to present  the Yosida approximation of a semi-linear backward stochastic differential equation in infinite dimension. Under suitable assumption and condition, an L2-convergence rate is established.

Design/methodology/approach

The authors establish a result concerning the L2-convergence rate of the solution of backward stochastic differential equation with jumps with respect to the Yosida approximation.

Findings

The authors carry out a convergence rate of Yosida approximation to the semi-linear backward stochastic differential equation in infinite dimension.

Originality/value

In this paper, the authors present the Yosida approximation of a semi-linear backward stochastic differential equation in infinite dimension. Under suitable assumption and condition, an L2-convergence rate is established.

Details

Arab Journal of Mathematical Sciences, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1319-5166

Keywords

Open Access
Article
Publication date: 28 February 2023

Nadia Mohdeb

In this article, the author discusses dynamical behaviors of a prey-predator population model with nonlinear harvesting rate and offers a mathematical analysis of the model.

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Abstract

Purpose

In this article, the author discusses dynamical behaviors of a prey-predator population model with nonlinear harvesting rate and offers a mathematical analysis of the model.

Design/methodology/approach

The design is by using modelization of populations interaction, qualitative theory of ordinary différential equations, bifurcations analysis, invariant center manifolds theory and Dulac's criterion.

Findings

The author studies the stability of solutions and the existence of periodic solutions in the model, and proves the existence of some invariant sets and the production of a transcritical together with a saddle-node bifurcation.

Practical implications

The author studies the effects of harvesting on the persistence and extinction properties and its influence in the perspectives of economic views.

Originality/value

The authors considers a predator–prey model with a new nonlinear form of harvesting rate. The author’s intention is to make conceptual adjustments to a well-known predator–prey model in order to incorporate the effects of harvesting.

Details

Arab Journal of Mathematical Sciences, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1319-5166

Keywords

Open Access
Article
Publication date: 5 April 2021

Samuel Ssekajja

The author considers an invariant lightlike submanifold M, whose transversal bundle tr…

Abstract

Purpose

The author considers an invariant lightlike submanifold M, whose transversal bundle tr(TM) is flat, in an indefinite Sasakian manifold M¯(c) of constant φ¯-sectional curvature c. Under some geometric conditions, the author demonstrates that c=1, that is, M¯ is a space of constant curvature 1. Moreover, M and any leaf M′ of its screen distribution S(TM) are, also, spaces of constant curvature 1.

Design/methodology/approach

The author has employed the techniques developed by K. L. Duggal and A. Bejancu of reference number 7.

Findings

The author has discovered that any totally umbilic invariant ligtlike submanifold, whose transversal bundle is flat, in an indefinite Sasakian space form is, in fact, a space of constant curvature 1 (see Theorem 4.4).

Originality/value

To the best of the author’s findings, at the time of submission of this paper, the results reported are new and interesting as far as lightlike geometry is concerned.

Details

Arab Journal of Mathematical Sciences, vol. 28 no. 1
Type: Research Article
ISSN: 1319-5166

Keywords

Open Access
Article
Publication date: 13 July 2021

Kenneth Halpern

This paper aims to develop a geometry of moral systems. Existing social choice mechanisms predominantly employ simple structures, such as rankings. A mathematical metric among…

Abstract

Purpose

This paper aims to develop a geometry of moral systems. Existing social choice mechanisms predominantly employ simple structures, such as rankings. A mathematical metric among moral systems allows us to represent complex sets of views in a multidimensional geometry. Such a metric can serve to diagnose structural issues, test existing mechanisms of social choice or engender new mechanisms. It also may be used to replace active social choice mechanisms with information-based passive ones, shifting the operational burden.

Design/methodology/approach

Under reasonable assumptions, moral systems correspond to computational black boxes, which can be represented by conditional probability distributions of responses to situations. In the presence of a probability distribution over situations and a metric among responses, codifying our intuition, we can derive a sensible metric among moral systems.

Findings

Within the developed framework, the author offers a set of well-behaved candidate metrics that may be employed in real applications. The author also proposes a variety of practical applications to social choice, both diagnostic and generative.

Originality/value

The proffered framework, derived metrics and proposed applications to social choice represent a new paradigm and offer potential improvements and alternatives to existing social choice mechanisms. They also can serve as the staging point for research in a number of directions.

Details

Asian Journal of Economics and Banking, vol. 5 no. 3
Type: Research Article
ISSN: 2615-9821

Keywords

Open Access
Article
Publication date: 17 September 2021

Aykut Akgün and Mehmet Gülbahar

Bi-slant submanifolds of S-manifolds are introduced, and some examples of these submanifolds are presented.

Abstract

Purpose

Bi-slant submanifolds of S-manifolds are introduced, and some examples of these submanifolds are presented.

Design/methodology/approach

Some properties of Di-geodesic and Di-umbilical bi-slant submanifolds are examined.

Findings

The Riemannian curvature invariants of these submanifolds are computed, and some results are discussed with the help of these invariants.

Originality/value

The topic is original, and the manuscript has not been submitted to any other journal.

Details

Arab Journal of Mathematical Sciences, vol. 30 no. 1
Type: Research Article
ISSN: 1319-5166

Keywords

Open Access
Article
Publication date: 22 May 2019

Adrian Magdaş

The purpose of this paper is to study the coupled fixed point problem and the coupled best proximity problem for single-valued and multi-valued contraction type operators defined…

Abstract

The purpose of this paper is to study the coupled fixed point problem and the coupled best proximity problem for single-valued and multi-valued contraction type operators defined on cyclic representations of the space. The approach is based on fixed point results for appropriate operators generated by the initial problems.

Open Access
Article
Publication date: 14 March 2019

Sabri T.M. Thabet, Bashir Ahmad and Ravi P. Agarwal

In this paper, we study a Cauchy-type problem for Hilfer fractional integrodifferential equations with boundary conditions. The existence of solutions for the given problem is…

Abstract

In this paper, we study a Cauchy-type problem for Hilfer fractional integrodifferential equations with boundary conditions. The existence of solutions for the given problem is proved by applying measure of noncompactness technique in an abstract weighted space. Moreover, we use generalized Gronwall inequality with singularity to establish continuous dependence and uniqueness of ϵ-approximate solutions.

Open Access
Article
Publication date: 4 December 2020

Sergei O. Kuznetsov, Alexey Masyutin and Aleksandr Ageev

The purpose of this study is to show that closure-based classification and regression models provide both high accuracy and interpretability.

Abstract

Purpose

The purpose of this study is to show that closure-based classification and regression models provide both high accuracy and interpretability.

Design/methodology/approach

Pattern structures allow one to approach the knowledge extraction problem in case of partially ordered descriptions. They provide a way to apply techniques based on closed descriptions to non-binary data. To provide scalability of the approach, the author introduced a lazy (query-based) classification algorithm.

Findings

The experiments support the hypothesis that closure-based classification and regression allow one to both achieve higher accuracy in scoring models as compared to results obtained with classical banking models and retain interpretability of model results, whereas black-box methods grant better accuracy for the cost of losing interpretability.

Originality/value

This is an original research showing the advantage of closure-based classification and regression models in the banking sphere.

Details

Asian Journal of Economics and Banking, vol. 4 no. 3
Type: Research Article
ISSN: 2615-9821

Keywords

Open Access
Article
Publication date: 22 February 2019

H. Fukhar-ud-din and A.R. Khan

The purpose of this paper is to introduce the implicit midpoint rule (IMR) of nonexpansive mappings in 2- uniformly convex hyperbolic spaces and study its convergence. Strong and â–…

Abstract

The purpose of this paper is to introduce the implicit midpoint rule (IMR) of nonexpansive mappings in 2- uniformly convex hyperbolic spaces and study its convergence. Strong and â–ł-convergence theorems based on this algorithm are proved in this new setting. The results obtained hold concurrently in uniformly convex Banach spaces, CAT(0) spaces and Hilbert spaces as special cases.

Details

Arab Journal of Mathematical Sciences, vol. 26 no. 1/2
Type: Research Article
ISSN: 1319-5166

Keywords

Open Access
Article
Publication date: 18 November 2020

Yuyang Zhang, Yonggang Leng, Hao Zhang, Xukun Su, Shuailing Sun, Xiaoyu Chen and Junjie Xu

An appropriate equivalent model is the key to the effective analysis of the system and structure in which permanent magnet takes part. At present, there are several equivalent…

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Abstract

Purpose

An appropriate equivalent model is the key to the effective analysis of the system and structure in which permanent magnet takes part. At present, there are several equivalent models for calculating the interacting magnetic force between permanent magnets including magnetizing current, magnetic charge and magnetic dipole–dipole model. How to choose the most appropriate and efficient model still needs further discussion.

Design/methodology/approach

This paper chooses cuboid, cylindrical and spherical permanent magnets as calculating objects to investigate the detailed calculation procedures based on three equivalent models, magnetizing current, magnetic charge and magnetic dipole–dipole model. By comparing the accuracies of those models with experiment measurement, the applicability of three equivalent models for describing permanent magnets with different shapes is analyzed.

Findings

Similar calculation accuracies of the equivalent magnetizing current model and magnetic charge model are verified by comparison between simulation and experiment results. However, the magnetic dipole–dipole model can only accurately calculate for spherical magnet instead of other nonellipsoid magnets, because dipole model cannot describe the specific characteristics of magnet's shape, only sphere can be treated as the topological form of a dipole, namely a filled dot.

Originality/value

This work provides reference basis for choosing a proper model to calculate magnetic force in the design of electromechanical structures with permanent magnets. The applicability of different equivalent models describing permanent magnets with different shapes is discussed and the equivalence between the models is also analyzed.

Details

Journal of Intelligent Manufacturing and Special Equipment, vol. 1 no. 1
Type: Research Article
ISSN: 2633-6596

Keywords

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