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714 Results Found

  • Article
  • Open Access
5 Citations
2,999 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
2 Citations
4,051 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
4,456 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)
  • Article
  • Open Access
2 Citations
4,474 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
544 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...

  • Feature Paper
  • Article
  • Open Access
6 Citations
3,669 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
2 Citations
4,824 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
3 Citations
2,783 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
2,187 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
8 Citations
2,526 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
1 Citations
536 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
331 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
3 Citations
2,119 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
301 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
10 Citations
2,263 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
5 Citations
1,306 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
2 Citations
2,873 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
5 Citations
2,202 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
18 Citations
3,392 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
3 Citations
884 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
382 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)
  • Article
  • Open Access
7 Citations
2,761 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)
  • Feature Paper
  • Article
  • Open Access
1 Citations
3,159 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
1 Citations
1,966 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
1 Citations
2,273 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
13 Citations
3,711 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
1 Citations
1,095 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)
  • Communication
  • Open Access
2,126 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)
  • Feature Paper
  • Article
  • Open Access
3 Citations
2,650 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
8 Citations
2,490 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
7,472 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
1,053 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
3 Citations
2,254 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
8 Citations
3,784 Views
17 Pages

Comparison of the Physical Care Burden on Formal Caregivers between Manual Human Care Using a Paper Diaper and Robot-Aided Care in Excretion Care

  • Jeong-Bae Ko,
  • Yong-Ku Kong,
  • Kyeong-Hee Choi,
  • Chang-Ki Lee,
  • Hyun-Ji Keum,
  • Jae-Soo Hong and
  • Byeong-Hee Won

Although the older population has been rapidly growing, the availability of formal caregivers remains limited. Assistance provided by care robots has helped lower this burden; however, whether using a care robot while providing excretion care (EC) is...

(This article belongs to the Special Issue Occupational Ergonomics: Design, Development, and Usability Evaluation of Ergonomic Products for Application in Various Industries)
  • Article
  • Open Access
1,041 Views
19 Pages

Scintigraphic Assessment of Lung Perfusion and Ventilation in Patients After Pneumonectomy

  • Karina Witkiewicz,
  • Małgorzata Edyta Wojtyś,
  • Norbert Wójcik,
  • Krzysztof Safranow,
  • Jarosław Pieróg,
  • Jacek Szulc,
  • Tadeusz Sulikowski,
  • Konrad Jarosz,
  • Tomasz Grodzki and
  • Janusz Wójcik

14 December 2025

Background/Objectives: The physiological ventilation–perfusion ratio (V/Q) in the upper pulmonary field is >3 and in the lower pulmonary field it is <1 due to the effect of gravity when the body is in an upright position. Pneumonectomy le...

(This article belongs to the Special Issue Innovations in Thoracic Surgery and Disease Management: Integrating Genomics, Technology, and Multidisciplinary Care)
  • Article
  • Open Access
336 Views
29 Pages

27 June 2026

Decision-making problems often involve simultaneous sources of uncertainty: interval-valued hesitation in expert judgments, positive–neutral–negative assessments, parameter-dependent evaluations, and boundary-region indiscernibility. To a...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
2 Citations
3,044 Views
15 Pages

17 July 2022

Much attention is focused on the relationship between rough sets and many-valued modal logic to deal with approximate reasoning. This paper discusses the graded modal logic and puts forward the graded many-valued modal logic G(S5). Secondly, by emplo...

(This article belongs to the Section Logic)
  • Article
  • Open Access
3,521 Views
15 Pages

25 October 2017

The paper contributes to stabilization problems of linear systems subject to time-varying delays. Drawing upon small gain criteria and robust analysis techniques, upper and lower bounds on the largest allowable time-varying delay are developed by usi...

  • Article
  • Open Access
4 Citations
2,367 Views
18 Pages

On a Measure of Tail Asymmetry for the Bivariate Skew-Normal Copula

  • Toshinao Yoshiba,
  • Takaaki Koike and
  • Shogo Kato

13 July 2023

Asymmetry in the upper and lower tails is an important feature in modeling bivariate distributions. This article focuses on the log ratio between the tail probabilities at upper and lower corners as a measure of tail asymmetry. Asymptotic behavior of...

(This article belongs to the Special Issue Research Topics Related to Skew-Symmetric Distributions)
  • Interesting Images
  • Open Access
2,457 Views
4 Pages

13 December 2022

Gastric MALToma is an extra-nodal marginal-type B-cell lymphoma. MALToma may occur secondary to chronic inflammation and autoimmunity. The most common gastrointestinal (GI) site of MALToma is the stomach, with approximately 50% of lesions occurring t...

(This article belongs to the Section Pathology and Molecular Diagnostics)
  • Article
  • Open Access
7 Citations
3,975 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)
  • Article
  • Open Access
3 Citations
1,357 Views
19 Pages

18 June 2025

This study establishes a transient numerical model for the gas–solid two-phase flow of ultrafine dry powder fire extinguishing agents released in the confined space based on the Fluent software platform. The model investigates the spatial flow...

  • Article
  • Open Access
12 Citations
3,642 Views
17 Pages

A Decision-Making Approach Based on a Multi Q-Hesitant Fuzzy Soft Multi-Granulation Rough Model

  • Kholood Mohammad Alsager,
  • Noura Omair Alshehri and
  • Muhammad Akram

4 December 2018

In this paper, we propose a new hybrid model, multi Q-hesitant fuzzy soft multi-granulation rough set model, by combining a multi Q-hesitant fuzzy soft set and multi-granulation rough set. We demonstrate some useful properties of these multi Q-hesita...

(This article belongs to the Special Issue Fuzzy Techniques for Decision Making 2018)
  • Article
  • Open Access
1,523 Views
16 Pages

22 August 2023

The relationship between Rough Set (RS) and algebraic systems has been long studied by mathematicians. RS is a growing research area that encourages studies into both real-world applications and the theory itself. In RS, a universe subset is characte...

(This article belongs to the Special Issue Recent Advances in Fuzzy Sets and Related Topics)
  • Article
  • Open Access
5 Citations
1,798 Views
20 Pages

15 November 2023

Covering granular reduction is an important issue in multi-covering information systems. The main methods to solve this problem are set operators. How to solve this problem by quantitative analysis is an interesting topic. Furthermore, as a type of n...

(This article belongs to the Special Issue Advances and Application of Fuzzy Sets, Decision Making and Soft Computing)
  • Article
  • Open Access
4 Citations
3,275 Views
12 Pages

19 September 2018

As a generalization of single value neutrosophic rough sets, the concept of multi-granulation neutrosophic rough sets was proposed by Bo et al., and some basic properties of the pessimistic (optimistic) multigranulation neutrosophic rough approximati...

(This article belongs to the Special Issue Discrete Mathematics and Symmetry)
  • Article
  • Open Access
716 Views
14 Pages

Investigation of Microscopic Oil Flow Characteristics During Fracturing Fluid Invasion and Flowback in Shale Oil Reservoirs

  • Yongqiang Zhang,
  • Wei Fan,
  • Chengwei Yang,
  • Yao Lu,
  • Yuanyuan Gao,
  • Xiuyu Wang and
  • Mei Li

23 November 2025

After hydraulic fracturing of C shale formation, it is difficult to get stable production, and the flowback efficiency of fracturing fluid is low. In order to reveal the law of fracturing fluid invasion and flowback behavior and to investigate the mi...

(This article belongs to the Special Issue Advanced Studies of Oil and Gas Flow in Unconventional Oil and Gas Reservoir)
  • Article
  • Open Access
10 Citations
2,669 Views
14 Pages

On Hybrid Type Nonlinear Fractional Integrodifferential Equations

  • Faten H. Damag,
  • Adem Kılıçman and
  • Awsan T. Al-Arioi

16 June 2020

In this paper, we introduce and investigate a hybrid type of nonlinear Riemann Liouville fractional integro-differential equations. We develop and extend previous work on such non-fractional equations, using operator theoretical techniques, and find...

(This article belongs to the Special Issue Nonlinear Equations: Theory, Methods, and Applications)

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