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1,795 Results Found

  • Article
  • Open Access
5 Citations
3,015 Views
16 Pages

26 December 2019

In the first part of our paper, we construct a cyclic hypergroup of matrices using the Ends Lemma. Its properties are then, in the second part of the paper, used to describe the symmetry of lower and upper approximations in certain rough sets with re...

(This article belongs to the Special Issue Symmetry in Classical and Fuzzy Algebraic Hypercompositional Structures)
  • Article
  • Open Access
1,699 Views
17 Pages

2 August 2023

In this paper, we find the sets of all extremal functions for approximations of the Hölder classes of H1 2π-periodic functions of one variable by the Favard sums, which coincide with the set of all extremal functions realizing the exact upper...

(This article belongs to the Special Issue Theory of Functions and Applications)
  • Article
  • Open Access
6 Citations
3,236 Views
20 Pages

Some Upper Bounds for RKHS Approximation by Bessel Functions

  • Mingdang Tian,
  • Baohuai Sheng and
  • Shuhua Wang

17 May 2022

A reproducing kernel Hilbert space (RKHS) approximation problem arising from learning theory is investigated. Some K-functionals and moduli of smoothness with respect to RKHSs are defined with Fourier–Bessel series and Fourier–Bessel tran...

(This article belongs to the Special Issue Numerical Computation, Approximation of Functions and Applied Mathematics)
  • Article
  • Open Access
12 Citations
2,759 Views
14 Pages

29 September 2023

We propose a direct digital frequency synthesizer (DDFS) by using an error-controlled piecewise linear (PWL) approximation method. For a given function and a preset max absolute error (MAE), this method iterates continuously from right to left within...

(This article belongs to the Topic Research on the Application of Digital Signal Processing)
  • Article
  • Open Access
2 Citations
4,070 Views
23 Pages

18 November 2022

The grade-added rough set (GRS) approach is an extension of the rough set theory proposed by Pawlak to deal with numerical data. However, the GRS has problems with overtraining, unclassified and unnatural results. In this study, we propose a new appr...

(This article belongs to the Section Data)
  • Article
  • Open Access
2 Citations
4,476 Views
29 Pages

Granular Structure of Type-2 Fuzzy Rough Sets over Two Universes

  • Juan Lu,
  • De-Yu Li,
  • Yan-Hui Zhai and
  • He-Xiang Bai

21 November 2017

Granular structure plays a very important role in the model construction, theoretical analysis and algorithm design of a granular computing method. The granular structures of classical rough sets and fuzzy rough sets have been proven to be clear. In...

(This article belongs to the Special Issue Fuzzy Sets Theory and Its Applications)
  • Feature Paper
  • Article
  • Open Access
8 Citations
3,782 Views
25 Pages

Jordan-Type Inequalities and Stratification

  • Miloš Mićović and
  • Branko Malešević

14 April 2024

In this paper, two double Jordan-type inequalities are introduced that generalize some previously established inequalities. As a result, some new upper and lower bounds and approximations of the sinc function are obtained. This extension of Jordan&rs...

(This article belongs to the Special Issue Advanced Approximation Techniques and Their Applications, 2nd Edition)
  • Article
  • Open Access
560 Views
19 Pages

6 March 2026

In this study, we investigate the upper- and lower-bound approximations of numerical eigenvalues derived by weak Galerkin spectral element methods on arbitrary convex quadrilateral meshes for the Laplace eigenvalue problem. Firstly, the Piola transfo...

  • Article
  • Open Access
2 Citations
4,540 Views
52 Pages

Based on the geometry of a radial function, a sequence of approximations for arcsine, arccosine and arctangent are detailed. The approximations for arcsine and arccosine are sharp at the points zero and one. Convergence of the approximations is prove...

  • Article
  • Open Access
1 Citations
565 Views
26 Pages

30 January 2026

This paper proposes a theoretical framework for studying rough intuitionistic fuzzy filters within the structure of BE-algebras. Building on rough set theory and intuitionistic fuzzy set theory, we introduce rough intuitionistic fuzzy filters via low...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
3 Citations
2,795 Views
15 Pages

Alexandrov L-Fuzzy Pre-Proximities

  • Yong Chan Kim and
  • Ju-Mok Oh

15 January 2019

In this paper, we introduce the concepts of Alexandrov L-fuzzy pre-proximities on complete residuated lattices. Moreover, we investigate their relations among Alexandrov L-fuzzy pre-proximities, Alexandrov L-fuzzy topologies, L-fuzzy upper approximat...

(This article belongs to the Section E1: Mathematics and Computer Science)
  • Article
  • Open Access
8 Citations
2,227 Views
20 Pages

20 September 2024

Rough set theory is a methodology that defines the definite or probable membership of an element for exploring data with uncertainty and incompleteness. It classifies data sets using lower and upper approximations to model uncertainty and missing inf...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
1,014 Views
19 Pages

Levitin–Polyak Well Posedness for Fuzzy Optimization Problems Through a Linear Ordering

  • Rattanaporn Wangkeeree,
  • Panatda Boonman and
  • Nithirat Sisarat

29 March 2026

We propose a reformulated notion of Levitin–Polyak (abbreviated as LP) well posedness for fuzzy optimization problems formulated in the fuzzy order-preserving (FOP) setting, where minimizing sequences are governed by a total ordering defined on...

(This article belongs to the Special Issue Advanced Studies in Mathematical Optimization and Machine Learning)
  • Article
  • Open Access
8 Citations
2,553 Views
31 Pages

Rough Semiring-Valued Fuzzy Sets with Application

  • Jiří Močkoř,
  • Petr Hurtik and
  • David Hýnar

29 June 2022

Many of the new fuzzy structures with complete MV-algebras as value sets, such as hesitant, intuitionistic, neutrosophic, or fuzzy soft sets, can be transformed into one type of fuzzy set with values in special complete algebras, called AMV-algebras....

(This article belongs to the Special Issue FSTA: Fuzzy Set Theory and Applications)
  • Article
  • Open Access
2 Citations
4,841 Views
19 Pages

1 March 2023

We consider the initial-boundary value problem of reaction-diffusion-advection that has a solution of a front form. The statement comes from the theory of wave physics. We study the question of the solution stabilizing to the stationary one. Proof of...

(This article belongs to the Special Issue Mathematical Modelling and Applications)
  • Article
  • Open Access
360 Views
19 Pages

8 May 2026

This paper focuses on constructing four novel multiquadric (MQ) quasi-interpolation operators. We conduct a comprehensive analysis of the essential properties of the proposed operators and further derive rigorous optimal upper and lower bounds for th...

(This article belongs to the Special Issue Nonlinear Systems: Dynamics, Control, Optimization and Applications in Science and Engineering, 4th Edition)
  • Article
  • Open Access
1 Citations
1,873 Views
24 Pages

18 July 2023

In the present paper, we aim to study the long-time behavior of a stochastic semi-linear degenerate parabolic equation on a bounded or unbounded domain and driven by a nonlinear noise. Since the theory of pathwise random dynamical systems cannot be a...

(This article belongs to the Special Issue Analytical Approaches to Nonlinear Dynamical Systems and Applications II)
  • Article
  • Open Access
3 Citations
2,140 Views
22 Pages

26 July 2023

An algorithm is presented for the construction of an asymptotic approximation of a stable stationary solution to a diffusion equation system in a two-dimensional domain with a smooth boundary and a source function that is discontinuous along some smo...

(This article belongs to the Collection Feature Papers in Randomized, Online and Approximation Algorithms)
  • Article
  • Open Access
373 Views
19 Pages

This paper investigates a class of nonlinear fractional differential equations with boundary value problems involving Caputo–Hadamard-type derivatives. By relaxing the monotonicity constraints on the nonlinear terms and considering more general...

  • Article
  • Open Access
1 Citations
2,780 Views
15 Pages

Upper Limb Neural Tension Test and Spinal Biomechanics: Insights from a Longitudinal Pilot Study

  • Massimo Rossi,
  • Marianna Signorini,
  • Ali Baram,
  • Mario De Robertis and ,
  • Gabriele Capo,
  • Marco Riva,
  • Maurizio Fornari,
  • Federico Pessina and
  • Carlo Brembilla
  • + 4 authors+ 0 author

Background: The Upper Limb Neural Tension Test (ULNTT) is a common assessment for neurodynamic function, yet the relationship between ULNTT findings and specific spinal biomechanical patterns remains poorly understood, particularly in the context of...

(This article belongs to the Special Issue Spine Biomechanics)
  • Article
  • Open Access
10 Citations
2,279 Views
17 Pages

18 March 2023

In rough set theory, the multiplicity of methods of calculating neighborhood systems is very useful to calculate the measures of accuracy and roughness. In line with this research direction, in this article we present novel kinds of rough neighborhoo...

  • Article
  • Open Access
13 Citations
5,712 Views
14 Pages

The present study offers mathematical calculations of the roll-coating procedure lubricated with an upper-convected Maxwell fluid. An incompressible isothermal viscoelastic fluid was considered, with both the roll and the porous web having uniform ve...

  • Article
  • Open Access
7 Citations
4,461 Views
15 Pages

Two Interval Upper-Bound Q-Function Approximations with Applications

  • Zoran Perić,
  • Aleksandar Marković,
  • Nataša Kontrec,
  • Jelena Nikolić and ,
  • Marko D. Petković and
  • Aleksandra Jovanović
  • + 1 author+ 0 author

1 October 2022

The Gaussian Q-function has considerable applications in numerous areas of science and engineering. However, the fact that a closed-form expression for this function does not exist encourages finding approximations or bounds of the Q-function. In thi...

(This article belongs to the Section E1: Mathematics and Computer Science)
  • Article
  • Open Access
7 Citations
4,005 Views
39 Pages

20 June 2020

This paper introduces an upper bound on the absolute difference between: ( a ) the cumulative distribution function (CDF) of the sum of a finite number of independent and identically distributed random variables with finite absolute third mom...

(This article belongs to the Special Issue Wireless Networks: Information Theoretic Perspectives)
  • Feature Paper
  • Article
  • Open Access
3 Citations
2,645 Views
14 Pages

Role of the Product λ′(0)ρ′(1) in Determining LDPC Code Performance

  • Francesca Vatta,
  • Fulvio Babich,
  • Flavio Ellero,
  • Matteo Noschese and ,
  • Giulia Buttazzoni and
  • Massimiliano Comisso
  • + 1 author+ 0 author

10 December 2019

The objective of this work is to analyze the importance of the product λ ′ ( 0 ) ρ ′ ( 1 ) in determining low density parity check (LDPC) code performance, as far as its influence on the weight distribution func...

(This article belongs to the Section Computer Science & Engineering)
  • Article
  • Open Access
6 Citations
1,327 Views
24 Pages

20 September 2024

This paper presents the novel concept of rough intuitionistic fuzzy ideals within the realm of BCK-algebras and investigates their fundamental properties. Furthermore, we introduce a set-valued homomorphism over a BCK-algebra, laying the foundation f...

(This article belongs to the Special Issue Algebra and Discrete Mathematics, 4th Edition)
  • Article
  • Open Access
8 Citations
2,779 Views
25 Pages

2 April 2021

In this work, the existence and nonexistence of stationary radial solutions to the elliptic partial differential equation arising in the molecular beam epitaxy are studied. Since we are interested in radial solutions, we focus on the fourth-order sin...

(This article belongs to the Special Issue New Trends on Boundary Value Problems)
  • Article
  • Open Access
5 Citations
2,218 Views
8 Pages

On Covering-Based Rough Intuitionistic Fuzzy Sets

  • R. Mareay,
  • Ibrahim Noaman,
  • Radwan Abu-Gdairi and
  • M. Badr

2 November 2022

Intuitionistic Fuzzy Sets (IFSs) and rough sets depending on covering are important theories for dealing with uncertainty and inexact problems. We think the neighborhood of an element is more realistic than any cluster in the processes of classificat...

  • Article
  • Open Access
19 Citations
3,428 Views
19 Pages

30 April 2023

The challenging issues of computer networks and databases are not only the intrusion detection but also the reduction of false positives and increase of detection rate. In any intrusion detection system, anomaly detection mainly focuses on modeling t...

(This article belongs to the Section Computing and Artificial Intelligence)
  • Article
  • Open Access
2 Citations
2,892 Views
11 Pages

A Class of Coupled Causal Differential Equations

  • Wen-Li Wang,
  • Jing-Feng Tian and
  • Wing-Sum Cheung

20 September 2018

In this thesis, we consider the existence of extreme solutions to a class of coupled causal differential equations. By utilizing two comparison theorems and a monotone iterative technique, we have obtained sufficient conditions under which the equati...

  • Article
  • Open Access
3 Citations
897 Views
15 Pages

20 June 2025

An important mathematical way to deal with ambiguity and uncertainty in knowledge is rough set (RS) theory. It is believed that a grill is a necessary addition to this idea. Since it expands the approximate of RSs, it is a helpful technique for remov...

(This article belongs to the Special Issue Topics in General Topology and Applications)
  • Article
  • Open Access
1 Citations
443 Views
17 Pages

7 August 2026

Given an ideal topological space (X,τ,I), we consider two opposite ways of idealizing the class of h-open sets. The first, the class of hI-open sets introduced by Açıkgöz and Noiri, pushes the ideal inward through the Jankovi...

(This article belongs to the Section B: Geometry and Topology)
  • Case Report
  • Open Access
2 Citations
4,587 Views
12 Pages

Upper Vascular Thoracic Outlet Syndrome: A Case Study

  • Agnieszka Wierciak-Rokowska,
  • Agnieszka Sliwka,
  • Mikolaj Maga,
  • Mateusz Gajda and ,
  • Katarzyna Bogucka,
  • Pawel Kaczmarczyk and
  • Pawel Maga
  • + 2 authors+ 0 author

Thoracic outlet syndrome (TOS) is recognised in approximately 8% of the population. Vascular presentation is rare and diagnosis is often elusive due to its rarity. As episodes of TOS in the upper extremities are rare, proven protocols for rehabilitat...

(This article belongs to the Special Issue Cardiac and Vascular Diseases: Pathogenesis, Pharmacological Treatments, Advances in Therapies (2nd Edition))
  • Feature Paper
  • Article
  • Open Access
1 Citations
3,193 Views
29 Pages

20 October 2023

Variational inference provides a way to approximate probability densities through optimization. It does so by optimizing an upper or a lower bound of the likelihood of the observed data (the evidence). The classic variational inference approach sugge...

(This article belongs to the Special Issue Entropy: The Cornerstone of Machine Learning)
  • Article
  • Open Access
419 Views
18 Pages

1 July 2026

We establish a new fixed point result for measurable-selection-valued correspondences with nonconvex and possibly disconnected values arising from the composition of Caratheodory functions with an upper Caratheodory (uC) correspondence. Using Carathe...

(This article belongs to the Special Issue Advances in Fixed Point Theory with Applications)
  • Feature Paper
  • Article
  • Open Access
3 Citations
2,669 Views
21 Pages

27 June 2021

For L a complete co-residuated lattice and R an L-fuzzy relation, an L-fuzzy upper approximation operator based on co-implication adjoint with L is constructed and discussed. It is proved that, when L is regular, the new approximation operator is the...

  • Article
  • Open Access
1 Citations
1,983 Views
23 Pages

18 November 2022

A multigranulation rough set (MGRS) model is an expansion of the Pawlak rough set, in which the uncertain concept is characterized by optimistic and pessimistic upper/lower approximate boundaries, respectively. However, there is a lack of approximate...

(This article belongs to the Special Issue Advances in Intelligent Data Analysis and Its Applications)
  • Article
  • Open Access
26 Citations
2,515 Views
12 Pages

Coefficient Estimation Utilizing the Faber Polynomial for a Subfamily of Bi-Univalent Functions

  • Abdullah Alsoboh,
  • Ala Amourah,
  • Fethiye Müge Sakar,
  • Osama Ogilat and ,
  • Gharib Mousa Gharib and
  • Nasser Zomot
  • + 1 author+ 0 author

24 May 2023

The paper introduces a new family of analytic bi-univalent functions that are injective and possess analytic inverses, by employing a q-analogue of the derivative operator. Moreover, the article establishes the upper bounds of the Taylor–Maclau...

(This article belongs to the Special Issue New Developments in Geometric Function Theory II)
  • Article
  • Open Access
1 Citations
1,847 Views
10 Pages

27 August 2023

The performance analysis of polarization M-ary differential chaos shift keying (P-MDCSK) has been expressed using a tight upper bound with the Q-function. However, evaluating the Q-function directly is not a closed expression and there has been less...

(This article belongs to the Section Complexity)
  • Article
  • Open Access
1 Citations
2,545 Views
35 Pages

Schröder based series for the principal and negative one branches of the Lambert W function are defined; the series are generic and are in terms of an initial, arbitrary, approximating function. Upper and lower bounds for the initial approximati...

  • Article
  • Open Access
1 Citations
1,126 Views
27 Pages

17 April 2025

This study investigates extremal solutions for fractional-order delayed difference equations, utilizing the Caputo nabla operator to establish mild lower and upper approximations via discrete fractional calculus. A new approach is employed to demonst...

(This article belongs to the Special Issue New Trends in Nonlinear Waves)
  • Article
  • Open Access
8 Citations
2,595 Views
21 Pages

9 February 2022

The rough set model for dual universes and multi granulation over dual universes is an interesting generalization of the Pawlak rough set model. In this paper, we present a pessimistic multigranulation roughness of a fuzzy set based on soft binary re...

(This article belongs to the Special Issue Fuzzy Sets and Artificial Intelligence)
  • Article
  • Open Access
32 Citations
7,493 Views
17 Pages

26 October 2016

Mixture models are in high demand for machine-learning analysis due to their computational tractability, and because they serve as a good approximation for continuous densities. Predominantly, entropy applications have been developed in the context o...

(This article belongs to the Collection Advances in Applied Statistical Mechanics)
  • Article
  • Open Access
1,071 Views
24 Pages

30 May 2025

A critical step for gene selection algorithms using rough set theory is the establishment of a gene evaluation function to assess the classification ability of candidate gene subsets. The concept of dependency in a classic neighborhood rough set mode...

  • Article
  • Open Access
13 Citations
3,734 Views
8 Pages

On Generalized Roughness in LA-Semigroups

  • Noor Rehman,
  • Choonkil Park,
  • Syed Inayat Ali Shah and
  • Abbas Ali

27 June 2018

The generalized roughness in LA-semigroups is introduced, and several properties of lower and upper approximations are discussed. We provide examples to show that the lower approximation of a subset of an LA-semigroup may not be an LA-subsemigroup/id...

(This article belongs to the Special Issue Fuzzy Mathematics)
  • Article
  • Open Access
6 Citations
3,034 Views
17 Pages

On Topologies on Simple Graphs and Their Applications in Radar Chart Methods

  • Husniyah Alzubaidi,
  • Ljubiša D. R. Kočinac and
  • Hakeem A. Othman

28 February 2025

This paper introduces a novel topology (upper approximated G-topology) on vertex sets of graphs using rough upper approximation neighborhoods, extending prior work on graph-induced topologies. Key results include characterizing discrete/indiscrete to...

(This article belongs to the Section Geometry and Topology)
  • Communication
  • Open Access
2,148 Views
14 Pages

29 May 2023

In this paper an algorithm for approximate solving of a boundary value problem for a nonlinear differential equation with a special type of fractional derivative is suggested. This derivative is called a generalized proportional Caputo fractional der...

(This article belongs to the Collection Feature Papers in Randomized, Online and Approximation Algorithms)
  • Article
  • Open Access
3 Citations
2,270 Views
16 Pages

19 August 2021

The main aim of the paper is to present an algorithm to solve approximately initial value problems for a scalar non-linear fractional differential equation with generalized proportional fractional derivative on a finite interval. The main condition i...

(This article belongs to the Special Issue Fractional Calculus and Nonlinear Systems)
  • Article
  • Open Access
412 Views
67 Pages

27 August 2026

Decision tables are widely used for representing and executing decision logic in business rules systems, regulatory compliance, and automated workflows. However, real-world decision tables often contain incomplete condition values. Existing rough set...

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