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1,385 Results Found

  • Article
  • Open Access
3 Citations
1,367 Views
19 Pages

Bi-Fuzzy S-Approximation Spaces

  • Ronghai Wang,
  • Xiaojie Xie and
  • Huilai Zhi

20 January 2025

The S-approximation spaces are significant extension of the rough set model and have been widely applied in intelligent decision-making. However, traditional S-approximation spaces are limited to two crisp universes, whereas bi-fuzzy universes (i.e.,...

(This article belongs to the Section D2: Operations Research and Fuzzy Decision Making)
  • Article
  • Open Access
1,363 Views
20 Pages

1 July 2024

We study L2-approximation problems in the weighted Hilbert spaces in the worst case setting. Three interesting weighted Hilbert spaces appear in this paper, whose weights are equipped with two positive parameters γj and αj for j∈N. W...

(This article belongs to the Special Issue Approximation Theory and Applications)
  • Article
  • Open Access
6 Citations
1,817 Views
29 Pages

27 September 2023

In life testing and reliability studies, most researchers have used the maximum likelihood estimation method to estimate unknown parameters, even though it has been proven that the maximum product of spacing method has properties as good as the maxim...

(This article belongs to the Section Mathematical Analysis)
  • Article
  • Open Access
11 Citations
1,357 Views
19 Pages

12 January 2026

In this work, we first establish a new connection between adjoint Bernoulli’s polynomials and gamma function as a new sequence of linear positive operators denoted by Sr,ς,λ(.;.). Further, convergence results for these sequences o...

(This article belongs to the Special Issue Numerical Analysis and Scientific Computing for Applied Mathematics)
  • Feature Paper
  • Article
  • Open Access
759 Views
14 Pages

15 April 2025

We study the gE-approximation property for the Banach space E=ℓq(ℓp), which is an extension of Saphar’s p-approximation property. We establish some characterizations of the gE-approximation property using the space of E-summing oper...

(This article belongs to the Section E: Applied Mathematics)
  • Article
  • Open Access
1,546 Views
11 Pages

22 September 2023

In rough set theory, there are many covering approximation spaces, so how to classify covering approximation spaces has become a hot issue. In this paper, we propose the concepts of a covering approximation T1-space, F-symmetry, covering rough contin...

  • Article
  • Open Access
2 Citations
819 Views
12 Pages

On Structral Properties of Some Banach Space-Valued Schröder Sequence Spaces

  • Yılmaz Yılmaz,
  • A. Nihal Tuncer and
  • Seçkin Yalçın

20 June 2025

Some properties on Banach spaces, such as the Radon–Riesz, Dunford–Pettis and approximation properties, allow us to better understand the naive details about the structure of space and the robust inhomogeneities and symmetries in space. I...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
6 Citations
2,061 Views
15 Pages

13 June 2023

The indentation of a power-law graded elastic half-space by a rigid counter body is considered in the framework of linear elasticity. Poisson’s ratio is assumed to be constant over the half-space. For indenters with an ellipsoidal power-law sha...

  • Article
  • Open Access
5 Citations
2,216 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
52 Citations
5,392 Views
10 Pages

Fractal Derivatives, Fractional Derivatives and q-Deformed Calculus

  • Airton Deppman,
  • Eugenio Megías and
  • Roman Pasechnik

30 June 2023

This work presents an analysis of fractional derivatives and fractal derivatives, discussing their differences and similarities. The fractal derivative is closely connected to Haussdorff’s concepts of fractional dimension geometry. The paper di...

(This article belongs to the Special Issue Non-additive Entropy Formulas: Motivation and Derivations)
  • Article
  • Open Access
1 Citations
1,517 Views
13 Pages

26 April 2024

In this work, we characterize the boundedness of t-generalized composition operators from F(p, q, s) spaces to iterated weighted-type Banach space. We also provide estimates of the norm and the essential norm of t-generalized composition op...

  • Article
  • Open Access
1,063 Views
22 Pages

5 October 2025

In this paper, we prove the theorems on the simultaneous approximation of a pair of analytic functions by discrete shifts (ζ(s+ikh1),ζ(s+ikh2,α)), h1>0, h2>0 of the Riemann zeta function ζ(s) and Hurwitz zeta function &zeta...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
2 Citations
3,451 Views
14 Pages

25 January 2017

Müntz spaces satisfying the Müntz and gap conditions are considered. A Fourier approximation of functions in the Müntz spaces MΛ,p of Lp functions is studied, where 1 < p < ∞. It is proven that up to an isomorphism and a change of variables, th...

  • Article
  • Open Access
1,503 Views
32 Pages

25 April 2023

Considered herein is the Cauchy problem of the two-component Novikov system. In the periodic case, we first constructed an approximate solution sequence that possesses the nonuniform dependence property; then, by applying the energy methods, we manag...

(This article belongs to the Section C1: Difference and Differential Equations)
  • Article
  • Open Access
15 Citations
1,668 Views
15 Pages

21 November 2024

This research work introduces a connection of adjoint Bernoulli’s polynomials and a gamma function as a sequence of linear positive operators. Further, the convergence properties of these sequences of operators are investigated in various funct...

(This article belongs to the Section E: Applied Mathematics)
  • Article
  • Open Access
4 Citations
2,242 Views
22 Pages

17 July 2023

In this article, we give the sharp bounds of probabilistic Kolmogorov N,δ-widths and probabilistic linear N,δ-widths of the multivariate Sobolev space W2A with common smoothness on a Sq norm equipped with the Gaussian measure μ, where...

(This article belongs to the Special Issue Advanced Approximation Techniques and Their Applications)
  • Article
  • Open Access
1 Citations
1,258 Views
14 Pages

14 January 2025

The aim of this paper is to apply polynomial approximation by sums of squares in several real variables to the multidimensional moment problem. The general idea is to approximate any element of the positive cone of the involved function space with su...

(This article belongs to the Special Issue Numerical Methods and Approximation Theory)
  • Article
  • Open Access
33 Citations
5,656 Views
16 Pages

Several Fixed Point Theorems in Convex b-Metric Spaces and Applications

  • Lili Chen,
  • Chaobo Li,
  • Radoslaw Kaczmarek and
  • Yanfeng Zhao

14 February 2020

Our paper is devoted to indicating a way of generalizing Mann’s iteration algorithm and a series of fixed point results in the framework of b-metric spaces. First, the concept of a convex b-metric space by means of a convex structure is introdu...

(This article belongs to the Special Issue Fixed Point Theory and Related Nonlinear Problems with Applications)
  • Article
  • Open Access
3 Citations
2,237 Views
13 Pages

Distributed-order, space-fractional diffusion equations are used to describe physical processes that lack power-law scaling. A fourth-order-accurate, A-stable time-stepping method was developed, analyzed, and implemented to solve inhomogeneous parabo...

(This article belongs to the Special Issue Numerical Solution and Applications of Fractional Differential Equations)
  • Article
  • Open Access
10 Citations
4,759 Views
15 Pages

Sampling and Mapping Chemical Space with Extended Similarity Indices

  • Kenneth López-Pérez,
  • Edgar López-López,
  • José L. Medina-Franco and
  • Ramón Alain Miranda-Quintana

30 August 2023

Visualization of the chemical space is useful in many aspects of chemistry, including compound library design, diversity analysis, and exploring structure–property relationships, to name a few. Examples of notable research areas where the visua...

(This article belongs to the Special Issue Computational Drug Discovery: Methods and Applications)
  • Article
  • Open Access
19 Citations
3,068 Views
19 Pages

On Ulam Stability of Functional Equations in 2-Normed Spaces—A Survey

  • Anna Bahyrycz,
  • Janusz Brzdęk,
  • El-sayed El-hady and
  • Zbigniew Leśniak

18 November 2021

The theory of Ulam stability was initiated by a problem raised in 1940 by S. Ulam and concerning approximate solutions to the equation of homomorphism in groups. It is somehow connected to various other areas of investigation such as, e.g., optimizat...

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

16 April 2026

In this paper, the uniform approximation of continuous functions on [0,1] by rational functions with prescribed poles and bounded multiplicities is studied. A classical theorem of Fichera characterizes density in C([0,1]) through the divergence of a...

(This article belongs to the Special Issue Symmetry in Complex Analysis Operators Theory)
  • Article
  • Open Access
501 Views
21 Pages

On Value Distribution of One Epstein Zeta-Function

  • Kalyan Chakraborty and
  • Antanas Laurinčikas

3 August 2026

The paper is devoted to Epstein zeta-function ζ3(s), s=σ+it, of a quadratic form of three variables. We obtain a probabilistic characterization of the function ζ3(s) in terms of weak convergence of probability measures in the space of...

(This article belongs to the Special Issue Special Functions, Representations and Applications)
  • Article
  • Open Access
7 Citations
2,308 Views
13 Pages

Analytical Approximate Solutions for Scalarized AdS Black Holes

  • De-Cheng Zou,
  • Bo Meng,
  • Ming Zhang,
  • Sheng-Yuan Li and ,
  • Meng-Yun Lai and
  • Yun Soo Myung
  • + 1 author+ 0 author

30 December 2022

The spontaneous scalarization of Schwarzscild-AdS is investigated in the Einstein-scalar-Gauss–Bonnet (ESGB) theory. Firstly, we construct scalarized AdS black holes numerically. Secondly, making use of the homotopy analysis method (HAM), we ob...

(This article belongs to the Special Issue Black Holes in Einstein–Gauss–Bonnet Theories)
  • Feature Paper
  • Article
  • Open Access
4 Citations
3,064 Views
10 Pages

Pancreatic Juice Cytology Evaluations Using Synthetic Secretin and Serial Pancreatic Juice Aspiration Cytological Examination for the Diagnosis of Pancreatic Ductal Adenocarcinoma

  • Yohei Takeda,
  • Kazuya Matsumoto,
  • Takumi Onoyama,
  • Taro Yamashita and ,
  • Hiroki Koda,
  • Wataru Hamamoto,
  • Yuri Sakamoto,
  • Takuya Shimosaka,
  • Shiho Kawahara and
  • Naoyuki Yamaguchi
  • + 9 authors+ 4 authors

Pathological examination by endoscopic ultrasound–fine needle aspiration is not possible in approximately 10% of pancreatic tumor cases. Pancreatic juice cytology (PJC) is considered an alternative diagnostic method. However, its diagnostic cap...

(This article belongs to the Special Issue Endoscopy and Diagnostic Tools in Hepatobiliary and Pancreatic Diseases)
  • Review
  • Open Access
3 Citations
3,258 Views
20 Pages

13 October 2021

In this pedagogical article, we explore a powerful language for describing the notion of spacetime and particle dynamics intrinsic to a given fundamental physical theory, focusing on special relativity and its Newtonian limit. The starting point of t...

(This article belongs to the Section C: Physics)
  • Article
  • Open Access
2 Citations
2,593 Views
24 Pages

The existence, uniqueness, and Carathe´odory’s successive approximation of the fractional neutral stochastic differential equation (FNSDE) in Hilbert space are considered in this paper. First, we give the Carathe´odory’s appro...

(This article belongs to the Section General Mathematics, Analysis)
  • Article
  • Open Access
1 Citations
1,248 Views
18 Pages

22 January 2026

Using the concept of category, we provide some insight into and prove an intrinsic property of the category AprS of approximation spaces and continuous functions. We also introduce rough closure and rough interior operators to characterize clopen top...

(This article belongs to the Section D2: Operations Research and Fuzzy Decision Making)
  • Article
  • Open Access
374 Views
18 Pages

Conditional Local Existence and Uniqueness for Impulsive Stochastic Differential Equations with State-Dependent Delay

  • Houari Charaf Eddine Bendjellal,
  • Mohamed Belaidi,
  • Zouaoui Chikr Elmezouar,
  • Fatimah Alshahrani and ,
  • Abderrahmane Belguerna and
  • Hamza Daoudi
  • + 1 author+ 0 author

22 August 2026

We consider impulsive stochastic delay differential equations with state-dependent impulse times, where the k-th impulse occurs at a time τ satisfying τ=τku(τ−). In generalized Lipschitz and growth conditions for coefficients, e...

(This article belongs to the Section C1: Difference and Differential Equations)
  • Feature Paper
  • Article
  • Open Access
1 Citations
1,109 Views
25 Pages

27 July 2025

The purpose of the article is to highlight the role of binomial polynomials in the construction of classes of positive linear approximation sequences on Banach spaces. Our results aim to introduce and study an integral extension in Kantorovich sense...

(This article belongs to the Section E: Applied Mathematics)
  • Article
  • Open Access
4 Citations
2,340 Views
9 Pages

New Applications of Perov’s Fixed Point Theorem

  • Sorin Mureşan,
  • Loredana Florentina Iambor and
  • Omar Bazighifan

4 December 2022

The goal of this paper is to consider a differential equation system written as an interesting equivalent form that has not been used before. Using Perov’s fixed point theorem in generalized metric spaces, the existence and uniqueness of the so...

(This article belongs to the Special Issue New Advances in Mathematical Analysis and Functional Analysis)
  • Article
  • Open Access
4 Citations
4,741 Views
8 Pages

8 April 2021

The thermal scattering law (TSL), i.e., S(α,β), represents the momentum and energy exchange phase space for a material. The incoherent and coherent components of the TSL correlate an atom’s trajectory with itself and/or with other atoms in the lattic...

(This article belongs to the Special Issue Selected Papers from PHYSOR 2020)
  • Article
  • Open Access
4 Citations
2,472 Views
13 Pages

25 June 2023

Great attention has been paid to the propagation of electromagnetic (EM) waves across the sea surface due to its important applications. Most of the previous research, however, focuses on the half-space model illustrating the deep sea environment. In...

  • Article
  • Open Access
5 Citations
2,270 Views
19 Pages

25 May 2023

This paper is devoted to the approximation of a certain class of analytic functions by shifts Z(s+iτ), τ∈R, of the modified Mellin transform Z(s) of the square of the Riemann zeta-function ζ(1/2+it). More precisely, we prove the exi...

  • Article
  • Open Access
1 Citations
2,175 Views
14 Pages

20 July 2025

The increasing complexity of urban structures has significantly elevated the risk and severity of façade fires in high-rise buildings. Unlike traditional models assuming continuous fuel beds, real-world fire scenarios often involve discrete co...

  • Article
  • Open Access
1,291 Views
19 Pages

14 November 2024

We study the multivariate L2-approximation problem APPd defined over a Banach space in the average case setting. The space is equipped with a zero-mean Gaussian measure with a weighted covariance kernel, which depends on parameter sequences α={...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
1,184 Views
24 Pages

6 January 2025

This article primarily examines the approximation properties of a weighted Sobolev space W2,κr defined on a sphere Sd−1 equipped with Gaussian measures. Specifically, this study focuses on both the average case and probabilistic case sett...

(This article belongs to the Section Mathematical Analysis)
  • Article
  • Open Access
4 Citations
2,833 Views
17 Pages

Almost Optimality of the Orthogonal Super Greedy Algorithm for μ-Coherent Dictionaries

  • Chunfang Shao,
  • Jincai Chang,
  • Peixin Ye,
  • Wenhui Zhang and
  • Shuo Xing

20 April 2022

We study the approximation capability of the orthogonal super greedy algorithm (OSGA) with respect to μ-coherent dictionaries in Hilbert spaces. We establish the Lebesgue-type inequalities for OSGA, which show that the OSGA provides an almost opti...

(This article belongs to the Special Issue Numerical Computation, Approximation of Functions and Applied Mathematics)
  • Article
  • Open Access
312 Views
27 Pages

3 September 2026

Spacing design for group cable bolt systems remains largely empirical and rarely considers stress interaction and displacement overlap together. This study develops a dual-index interaction framework for two representative cable bolt configurations i...

(This article belongs to the Special Issue Advanced Technologies in Rock Mechanics and Mining Science)
  • Article
  • Open Access
4 Citations
6,276 Views
14 Pages

9 March 2016

The distribution of word probabilities in the monkey model of Zipf’s law is associated with two universality properties: (1) the exponent in the approximate power law approaches −1...

(This article belongs to the Section Information Theory, Probability and Statistics)
  • Article
  • Open Access
213 Views
26 Pages

1 October 2026

Trajectory planning for parallel manipulators in dynamic environments entails high computational costs, as geometric collision checks must be repeated whenever the environment changes. This paper proposes a trajectory planning method that shifts the...

(This article belongs to the Section Robotics, Mechatronics and Intelligent Machines)
  • Article
  • Open Access
2 Citations
5,854 Views
15 Pages

23 July 2015

We see how we can improve the accessibility of Newton’s method for approximating a solution of a nonlinear equation in Banach spaces when a center Hölder condition on the first derivative is used to prove its semi-local convergence.

(This article belongs to the Special Issue Numerical Algorithms for Solving Nonlinear Equations and Systems)
  • Article
  • Open Access
32 Citations
8,254 Views
26 Pages

22 November 2022

Ship route planning is a crucial activity that must consider not only the safety of the ship but also the safe passage of nearby ships in the same space and time. This study aims to provide general route-planning guidance to shipping traffic by impro...

(This article belongs to the Section Ocean Engineering)
  • Article
  • Open Access
5 Citations
790 Views
15 Pages

17 November 2025

This paper is devoted to the investigation of existence and approximate controllability results for a class of fractional integro-differential equations formulated in Fréchet spaces. The analysis is carried out using a generalized version of D...

(This article belongs to the Special Issue Advances in Fractional Calculus for Modeling and Applications)
  • Article
  • Open Access
2 Citations
8,802 Views
12 Pages

A Cylindrical Optical-Space Black Hole Induced from High-Pressure Acoustics in a Dense Fluid

  • Edward A. Rietman,
  • Brandon Melcher,
  • Alexey Bobrick and
  • Gianni Martire

28 March 2023

We describe the construction of an optical-space, cylindrical black hole induced by high pressure in a dense fluid. Using an approximate analogy between curved spacetime and optics in moving dielectric media, we derive the mass of the black hole thus...

(This article belongs to the Topic Applications of Photonics, Laser, Plasma and Radiation Physics)
  • Article
  • Open Access
23 Citations
4,277 Views
11 Pages

In this paper, we study a three step iterative scheme to approximate fixed points of Suzuki’s generalized non-expansive mappings. We establish some weak and strong convergence results for such mappings in uniformly convex Banach spaces. Further...

(This article belongs to the Special Issue Fixed Point, Optimization, and Applications)
  • Article
  • Open Access
8 Citations
2,549 Views
20 Pages

Research on Short-Term Forecasting Model of Global Atmospheric Temperature and Wind in the near Space Based on Deep Learning

  • Xingxin Sun,
  • Chen Zhou,
  • Jian Feng,
  • Huiyun Yang and ,
  • Yuqiang Zhang,
  • Zhou Chen,
  • Tong Xu,
  • Zhongxin Deng,
  • Zhengyu Zhao and
  • Ting Lan
  • + 6 authors+ 1 author

4 September 2024

Developing short-term forecasting models for global atmospheric temperature and wind in near space is crucial for understanding atmospheric dynamics and supporting human activities in this region. While numerical models have been extensively develope...

(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)
  • Article
  • Open Access
672 Views
24 Pages

2 June 2026

To provide a ground-based experimental reference for free-space optical time–frequency synchronization in future space applications, this paper investigates the impact of beam drift and dynamic link-state variations on free-space laser links. A...

(This article belongs to the Special Issue Cutting-Edge Developments in Optical Communications, Perception and Computing)
  • Article
  • Open Access
12 Citations
3,328 Views
18 Pages

A Fast Preconditioned Semi-Implicit Difference Scheme for Strongly Nonlinear Space-Fractional Diffusion Equations

  • Yu-Yun Huang,
  • Xian-Ming Gu,
  • Yi Gong,
  • Hu Li and ,
  • Yong-Liang Zhao and
  • Bruno Carpentieri
  • + 1 author+ 0 author

In this paper, we propose a semi-implicit difference scheme for solving one-dimensional nonlinear space-fractional diffusion equations. The method is first-order accurate in time and second-order accurate in space. It uses a fractional central differ...

(This article belongs to the Special Issue Novel Numerical Solutions of Fractional PDEs)

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