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4,466 Results Found

  • Article
  • Open Access
5 Citations
1,494 Views
14 Pages

Shannon’s Sampling Theorem for Set-Valued Functions with an Application

  • Yılmaz Yılmaz,
  • Bağdagül Kartal Erdoğan and
  • Halise Levent

25 September 2024

In this study, we defined a kind of Fourier expansion of set-valued square-integrable functions. In fact, we have seen that the classical Fourier basis also constitutes a basis for the Hilbert quasilinear space L2(−π,π,Ω(C)) of &Ome...

  • Article
  • Open Access
3 Citations
2,300 Views
33 Pages

15 September 2021

A theory for set-valued functions is developed, which are translative with respect to a linear operator. It is shown that such functions cover a wide range of applications, from projections in Hilbert spaces, set-valued quantiles for vector-valued ra...

(This article belongs to the Special Issue Applied Mathematical Methods in Financial Risk Management)
  • Article
  • Open Access
4 Citations
2,057 Views
14 Pages

6 July 2023

The decomposition integrals of set-valued functions with regards to fuzzy measures are introduced in a natural way. These integrals are an extension of the decomposition integral for real-valued functions and include several types of set-valued integ...

  • Article
  • Open Access
2,115 Views
15 Pages

On a Certain Generalized Functional Equation for Set-Valued Functions

  • Yaroslav Bazaykin,
  • Dušan Bednařík,
  • Veronika Borůvková and
  • Tomáš Zuščák

19 December 2020

The aim of the paper is to generalize results by Sikorska on some functional equations for set-valued functions. In the paper, a tool is described for solving a generalized type of an integral-functional equation for a set-valued function F:X→cc...

  • Article
  • Open Access
1 Citations
946 Views
24 Pages

17 March 2025

Fault diagnosis is crucial for ensuring the reliability and safety of wind energy conversion systems (WECSs). However, existing methods are often specific to components or specific types of wind turbines and face challenges, such as difficulty in thr...

(This article belongs to the Section A: Computer Science)
  • Article
  • Open Access
1 Citations
2,058 Views
14 Pages

20 January 2022

In this paper, by using the normal subdifferential and equilibrium-like function we first obtain some properties for K-preinvex set-valued maps. Secondly, in terms of this equilibrium-like function, we establish some sufficient conditions for the exi...

(This article belongs to the Special Issue Applied Functional Analysis and Applications)
  • Article
  • Open Access
17 Citations
2,478 Views
19 Pages

Some Novel Inequalities for LR-(k,h-m)-p Convex Interval Valued Functions by Means of Pseudo Order Relation

  • Vuk Stojiljković,
  • Rajagopalan Ramaswamy,
  • Ola A. Ashour Abdelnaby and
  • Stojan Radenović

In this paper, a new type of convexity is defined, namely, the left–right-(k,h-m)-p IVM (set-valued function) convexity. Utilizing the definition of this new convexity, we prove the Hadamard inequalities for noninteger Katugampola integrals. Th...

(This article belongs to the Special Issue Mathematical Inequalities in Fractional Calculus and Applications)
  • Article
  • Open Access
218 Views
39 Pages

Alternating Points of Set-Valued Mappings in Strong Partial b-Metric Spaces with Applications to Economic and Linguistic Adjustment

  • Atanas Ilchev,
  • Vanya Ivanova,
  • Rumen Marinov,
  • Diana Nedelcheva and ,
  • Angel Todorov and
  • Boyan Zlatanov
  • + 1 author+ 0 author

2 October 2026

This paper introduces and studies alternating points of two set-valued mappings acting between two 0-complete strong partial b-metric spaces. An alternating point is a mutually compatible pair of states, each of which belongs to the image of the othe...

(This article belongs to the Special Issue Applied Mathematics and Mathematical Modeling, 2nd Edition)
  • Feature Paper
  • Article
  • Open Access
1,204 Views
14 Pages

4 April 2025

We address the problem of approximating a set-valued function F, where F:[a,b]→K(Rd) given its samples {F(a+ih)}i=0N, with h=(b−a)/N. We revisit an existing method that approximates set-valued functions by interpolating signed-distance fun...

(This article belongs to the Section C1: Difference and Differential Equations)
  • Feature Paper
  • Article
  • Open Access
1,886 Views
21 Pages

8 May 2024

We present existing results and properties for the solutions of some vector equilibrium problems with set-valued functions in the case of a vector space ordered by a cone with some “interiority” properties. Some applications concerning th...

  • Article
  • Open Access
9 Citations
2,756 Views
8 Pages

14 December 2020

In this paper, we study the structure of trajectories of discrete disperse dynamical systems with a Lyapunov function which are generated by set-valued mappings. We establish a weak version of the turnpike property which holds for all trajectories of...

(This article belongs to the Special Issue Optimal Control Theory)
  • Article
  • Open Access
12 Citations
2,198 Views
29 Pages

Fractional calculus provides some fractional operators for us to model different real-world phenomena mathematically. One of these important study fields is the mathematical model of the elastic beam changes. More precisely, in this paper, based on t...

(This article belongs to the Special Issue Advances in Boundary Value Problems for Fractional Differential Equations, 2nd Edition)
  • Article
  • Open Access
1 Citations
277 Views
36 Pages

15 September 2026

This paper establishes a local fixed point theorem for multivalued mappings in zero-complete strong partial b-metric spaces and develops a framework for modelling multistage processes with several admissible terminal states. The contractive condition...

(This article belongs to the Special Issue Applied Mathematics and Numerical Analysis: Theory and Applications, 2nd Edition)
  • Feature Paper
  • Article
  • Open Access
4 Citations
2,314 Views
13 Pages

26 October 2022

In the paper, we consider functional set-valued integral equations whose representation contains set-valued integrals occurring symmetrically on both sides of the equation. On the coefficients of the equation, we impose certain conditions, more gener...

(This article belongs to the Special Issue Symmetry in Functional Equations and Analytic Inequalities III)
  • Article
  • Open Access
9 Citations
2,425 Views
14 Pages

7 July 2021

In this paper, we consider functional set-valued differential equations in their integral representations that possess integrals symmetrically on both sides of the equations. The solutions have values that are the nonempty compact and convex subsets....

(This article belongs to the Special Issue Symmetry in Functional Equations and Analytic Inequalities II)
  • Article
  • Open Access
1 Citations
2,307 Views
11 Pages

Hyers–Ulam–Rassias Stability of Set Valued Additive and Cubic Functional Equations in Several Variables

  • Parbati Saha,
  • Tapas K. Samanta,
  • Nabin C. Kayal,
  • Binayak S. Choudhury and
  • Manuel de la Sen

10 September 2019

In this paper, we establish Hyers–Ulam–Rassias stability results belonging to two different set valued functional equations in several variables, namely additive and cubic. The results are obtained in the contexts of Banach spaces. The wo...

(This article belongs to the Special Issue Functional Inequalities and Equations)
  • Article
  • Open Access
17 Citations
1,764 Views
21 Pages

23 September 2023

The application of fractional calculus to interval analysis is vital for the precise derivation of integral inequalities on set-valued mappings. The objective of this article is to reformulated the well-known Hermite–Hadamard inequality into va...

(This article belongs to the Special Issue Variational Problems and Applications, 2nd Edition)
  • Article
  • Open Access
1 Citations
2,455 Views
11 Pages

1 November 2019

We present the concept of multivalued mappings in generalized modular metric spaces (GMMS). In addition, we give Caristi and Feng-Liu fixed point results for this type of mappings in GMMS. Then, we obtain an application for final outcomes in the sens...

(This article belongs to the Section E1: Mathematics and Computer Science)
  • Article
  • Open Access
1,318 Views
43 Pages

13 May 2025

After establishing some basic facts on binary relations and sequential convergences, we prove a relational modification of a false, but interesting lemma of Paweł Pasteczka on the constancy of the composition of certain set-valued functions [The...

(This article belongs to the Collection Topology and Foundations)
  • Article
  • Open Access
3 Citations
2,188 Views
8 Pages

29 March 2021

In this work, we obtain a weak version of the turnpike property of trajectories of perturbed discrete disperse dynamical systems, which have a prototype in mathematical economics.

(This article belongs to the Special Issue Advances in Analysis and Control of Systems with Uncertainties)
  • Article
  • Open Access
6 Citations
2,051 Views
21 Pages

15 March 2022

This paper is devoted to provide sufficient Karush Kuhn Tucker (in short, KKT) conditions of optimality of second-order for a set-valued fractional minimax problem. In addition, we define duals of the types Mond-Weir and Wolfe of second-order for the...

  • Article
  • Open Access
2 Citations
2,214 Views
21 Pages

In this paper, we present the generalized iterated function system for the construction of common fractals of generalized contractive mappings in the setup of dislocated metric spaces. The well-posedness of attractors’ problems of rational cont...

  • Article
  • Open Access
22 Citations
5,178 Views
17 Pages

On Some New Fixed Point Results in Complete Extended b-Metric Spaces

  • Quanita Kiran,
  • Nayab Alamgir,
  • Nabil Mlaiki and
  • Hassen Aydi

In this paper, we specified a method that generalizes a number of fixed point results for single and multi-valued mappings in the structure of extended b-metric spaces. Our results extend several existing ones including the results of Aleksic et al....

(This article belongs to the Special Issue Fixed Point Theory and Dynamical Systems with Applications)
  • Article
  • Open Access
4 Citations
1,896 Views
25 Pages

30 October 2023

Hybrid contractions serve as a flexible and versatile framework for establishing fixed-point Theorems and analyzing the convergence of iterative algorithms. This paper demonstrates the adapted form of the admissible hybrid fuzzy Z-contraction in the...

(This article belongs to the Section D2: Operations Research and Fuzzy Decision Making)
  • Article
  • Open Access
50 Citations
4,943 Views
30 Pages

Minkowski Weighted Score Functions of Intuitionistic Fuzzy Values

  • Feng Feng,
  • Yujuan Zheng,
  • José Carlos R. Alcantud and
  • Qian Wang

13 July 2020

In multiple attribute decision-making in an intuitionistic fuzzy environment, the decision information is sometimes given by intuitionistic fuzzy soft sets. In order to address intuitionistic fuzzy decision-making problems in a more efficient way, ma...

(This article belongs to the Special Issue Fuzzy Sets and Soft Computing)
  • Article
  • Open Access
44 Citations
2,916 Views
17 Pages

Centroid Transformations of Intuitionistic Fuzzy Values Based on Aggregation Operators

  • Xiaoyan Liu,
  • Hee Sik Kim,
  • Feng Feng and
  • José Carlos R. Alcantud

24 October 2018

Atanassov’s intuitionistic fuzzy sets extend the notion of fuzzy sets. In addition to Zadeh’s membership function, a non-membership function is also considered. Intuitionistic fuzzy values play a crucial role in both theoretical and pract...

  • Article
  • Open Access
7 Citations
2,459 Views
14 Pages

22 December 2020

Following the well-known theory of Beurling and Roumieu ultradistributions, we investigate new spaces of ultradistributions as dual spaces of test functions which correspond to associated functions of logarithmic-type growth at infinity. In the given...

(This article belongs to the Special Issue Microlocal and Time-Frequency Analysis)
  • Article
  • Open Access
358 Views
32 Pages

15 September 2026

This paper introduces the concept of interval-valued T-spherical hesitant fuzzy set (IVTSHFS). Derived from the T-spherical fuzzy set, the IVTSHFS allows the membership, abstinence, and non-membership degrees of an element to be expressed as both int...

(This article belongs to the Special Issue Research on Fuzzy Logic and Mathematics with Applications, 4th Edition)
  • Article
  • Open Access
3,069 Views
26 Pages

22 January 2022

The interval-valued q-rung dual hesitant linguistic (IVq-RDHL) sets are widely used to express the evaluation information of decision makers (DMs) in the process of multi-attribute decision-making (MADM). However, the existing MADM method based on IV...

(This article belongs to the Section Information Theory, Probability and Statistics)
  • Article
  • Open Access
6 Citations
2,512 Views
22 Pages

13 July 2022

Global economic integration drives the development of dynamic competition. In a dynamic competitive environment, the ever-changing customer demands and technology directly affect the leadership of the core competence of enterprises. Therefore, assess...

(This article belongs to the Special Issue Fuzzy Applications in Industrial Engineering II)
  • Article
  • Open Access
1 Citations
2,926 Views
14 Pages

16 February 2023

This paper is devoted to investigating the existence of solutions for the fractional differential equation and fractional differential inclusion of order α∈(2,3] with affine periodic boundary value conditions. Applying the Leray–Scha...

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

11 March 2026

In this article, we introduce the notion of approximate convexity for set-valued mappings, specifically in the forms of approximate pseudoconvexity and approximate quasiconvexity. These generalizations are motivated by the need to handle optimization...

  • Article
  • Open Access
1 Citations
1,656 Views
14 Pages

1 November 2022

In this article, we consider a Riemann–Liouville fractional-order nonlinear hybrid delay differential inclusion with a nonlinear set-valued nonlocal integral condition of fractional order. We prove some existence and uniqueness results in C(I,R...

  • Article
  • Open Access
2,047 Views
18 Pages

Feng-Liu’s Approach to Fixed Point Results of Intuitionistic Fuzzy Set-Valued Maps

  • Mohammed Shehu Shagari,
  • Trad Alotaibi,
  • Rehana Tabassum,
  • Awad A. Bakery and ,
  • OM Kalthum S. K. Mohamed and
  • Arafa O. Mustafa
  • + 1 author+ 0 author

18 April 2023

The applications of non-zero self distance function have recently been discovered in both symmetric and asymmetric spaces. With respect to invariant point results, the available literature reveals that the idea has only been examined for crisp mappin...

(This article belongs to the Special Issue New Trends in Fixed Point Theory with Emphasis on Symmetry)
  • Article
  • Open Access
11 Citations
2,800 Views
7 Pages

4 March 2020

The symmetry concept is a congenital characteristic of the metric function. In this paper, our primary aim is to study the fixed points of a broad category of set-valued maps which may include discontinuous maps as well. To achieve this objective, we...

  • Article
  • Open Access
10 Citations
3,677 Views
12 Pages

Decision-Making with Fuzzy Soft Matrix Using a Revised Method: A Case of Medical Diagnosis of Diseases

  • Taiwo Olubunmi Sangodapo,
  • Babatunde Oluwaseun Onasanya and
  • Sarka Mayerova-Hoskova

19 September 2021

In this paper, we study the matrix representation of fuzzy soft sets, complement of fuzzy soft sets, product of fuzzy soft matrices and the application of fuzzy soft matrices in medical diagnosis presented by Lavanya and Akila. Additionally, a new me...

(This article belongs to the Section D2: Operations Research and Fuzzy Decision Making)
  • Article
  • Open Access
1 Citations
7,635 Views
11 Pages

26 July 2010

The metric average is a binary operation between sets in Rn which is used in the approximation of set-valued functions. We introduce an algorithm that applies tools of computational geometry to the computation of the metric average of 2D sets with pi...

(This article belongs to the Special Issue Algorithms for Applied Mathematics)
  • Article
  • Open Access
1 Citations
689 Views
19 Pages

This paper investigates a friction oscillator model in both its Integer-Order and Fractional-Order formulations. The lack of classical solutions for the governing differential equations with discontinuous right-hand sides is addressed by adopting a D...

(This article belongs to the Special Issue Numerical Solution and Applications of Fractional Differential Equations, 3rd Edition)
  • Feature Paper
  • Article
  • Open Access
16 Citations
4,003 Views
17 Pages

The Riemann-Lebesgue Integral of Interval-Valued Multifunctions

  • Danilo Costarelli,
  • Anca Croitoru,
  • Alina Gavriluţ,
  • Alina Iosif and
  • Anna Rita Sambucini

20 December 2020

We study Riemann-Lebesgue integrability for interval-valued multifunctions relative to an interval-valued set multifunction. Some classic properties of the RL integral, such as monotonicity, order continuity, bounded variation, convergence are obtain...

(This article belongs to the Special Issue Set-Valued Analysis)
  • Article
  • Open Access
11 Citations
3,388 Views
15 Pages

Convergence Theorems in Interval-Valued Riemann–Lebesgue Integrability

  • Anca Croitoru,
  • Alina Gavriluţ,
  • Alina Iosif and
  • Anna Rita Sambucini

30 January 2022

We provide some limit theorems for sequences of Riemann–Lebesgue integrable functions. More precisely, Lebesgue-type convergence and Fatou theorems are established. Then, these results are extended to the case of Riemann–Lebesgue integrable interval-...

  • Article
  • Open Access
3 Citations
2,214 Views
12 Pages

Inequalities in Riemann–Lebesgue Integrability

  • Anca Croitoru,
  • Alina Gavriluţ,
  • Alina Iosif and
  • Anna Rita Sambucini

22 December 2023

In this paper, we prove some inequalities for Riemann–Lebesgue integrable functions when the considered integration is obtained via a non-additive measure, including the reverse Hölder inequality and the reverse Minkowski inequality. Then,...

  • Feature Paper
  • Article
  • Open Access
2,352 Views
15 Pages

P-Algebras

  • Elijah Eghosa Edeghagba,
  • Branimir Šešelja and
  • Andreja Tepavčević

23 January 2025

Following the notions of Ω-set and Ω-algebra where Ω is a complete lattice, we introduce P-algebras, replacing the lattice Ω by a poset P. A P-algebra is a classical algebraic structure in which the usual equality is replaced...

(This article belongs to the Section Algebra and Number Theory)
  • Article
  • Open Access
19 Citations
2,265 Views
16 Pages

Interval Fejér-Type Inequalities for Left and Right-λ-Preinvex Functions in Interval-Valued Settings

  • Tareq Saeed,
  • Muhammad Bilal Khan,
  • Savin Treanțǎ,
  • Hamed H. Alsulami and
  • Mohammed Sh. Alhodaly

27 July 2022

For left and right λ-preinvex interval-valued functions (left and right λ-preinvex IVFs) in interval-valued Riemann operator settings, we create Hermite–Hadamard (H-H) type inequalities in the current study. Additionally, we creat...

(This article belongs to the Special Issue Current Research on Mathematical Inequalities)
  • Feature Paper
  • Article
  • Open Access
15 Citations
2,600 Views
7 Pages

8 January 2020

The symmetry concept is an intrinsic property of metric spaces as the metric function generalizes the notion of distance between two points. There are several remarkable results in science in connection with symmetry principles that can be proved usi...

  • Article
  • Open Access
7 Citations
2,798 Views
16 Pages

12 January 2022

In this paper, we study a semilinear integro-differential inclusion in Banach spaces, under the action of infinitely many impulses. We provide the existence of mild solutions on a half-line by means of the so-called extension-with-memory technique, w...

(This article belongs to the Special Issue Set-Valued Analysis II)
  • Article
  • Open Access
20 Citations
2,887 Views
25 Pages

I.V-CR-γ-Convex Functions and Their Application in Fractional Hermite–Hadamard Inequalities

  • Miguel Vivas-Cortez,
  • Sofia Ramzan,
  • Muhammad Uzair Awan,
  • Muhammad Zakria Javed and ,
  • Awais Gul Khan and
  • Muhammad Aslam Noor
  • + 1 author+ 0 author

12 July 2023

In recent years, the theory of convexity has influenced every field of mathematics due to its unique characteristics. Numerous generalizations, extensions, and refinements of convexity have been introduced, and one of them is set-valued convexity. In...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
1 Citations
1,805 Views
13 Pages

12 September 2023

In this paper, we consider optimization problems with stochastic constraints. We derive quantitative stability results for the optimal value function, the optimal solution set and the feasible solution set of optimization models in which the underlyi...

  • Article
  • Open Access
15 Citations
2,185 Views
18 Pages

Hermite–Hadamard Type Inclusions for Interval-Valued Coordinated Preinvex Functions

  • Kin Keung Lai,
  • Shashi Kant Mishra,
  • Jaya Bisht and
  • Mohd Hassan

8 April 2022

The connection between generalized convexity and symmetry has been studied by many authors in recent years. Due to this strong connection, generalized convexity and symmetry have arisen as a new topic in the subject of inequalities. In this paper, we...

(This article belongs to the Special Issue Symmetry in Mathematical Analysis and Functional Analysis)
  • Article
  • Open Access
1 Citations
1,468 Views
22 Pages

4 December 2024

In this paper, we deal with the properties and applications of a nonlinear scalarization function for sets by using the Minkowski difference. Under some suitable assumptions, the continuity and convexity concerned with the nonlinear scalarization fun...

(This article belongs to the Special Issue Fixed Point, Optimization, and Applications II)
  • Article
  • Open Access
2 Citations
2,371 Views
14 Pages

Two Positive Solutions for Elliptic Differential Inclusions

  • Gabriele Bonanno,
  • Valeria Morabito,
  • Donal O’Regan and
  • Bruno Vassallo

5 November 2024

The existence of two positive solutions for an elliptic differential inclusion is established, assuming that the nonlinear term is an upper semicontinuous set-valued mapping with compact convex values having subcritical growth. Our approach is based...

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