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  • SEMT valuation and strength of subdivided star of K 1,4
    Open Math. (IF 0.773) Pub Date : 2020-10-20
    Salma Kanwal; Mariam Imtiaz; Nazeran Idrees; Zurdat Iftikhar; Tahira Sumbal Shaikh; Misbah Arshad; Rida Irfan

    This study focuses on finding super edge-magic total (SEMT) labeling and deficiency of imbalanced fork and disjoint union of imbalanced fork with star, bistar and path; in addition, the SEMT strength for Imbalanced Fork is investigated.

  • Results on nonlocal stochastic integro-differential equations driven by a fractional Brownian motion
    Open Math. (IF 0.773) Pub Date : 2020-10-20
    Louk-Man Issaka; Mamadou Abdoul Diop; Hasna Hmoyed

    This paper deals with the existence of mild solutions for a class of non-local stochastic integro-differential equations driven by a fractional Brownian motion with Hurst parameter H∈12,1. Discussions are based on resolvent operators in the sense of Grimmer, stochastic analysis theory and fixed-point criteria. As a final point, an example is given to illustrate the effectiveness of the obtained theory

  • On surrounding quasi-contractions on non-triangular metric spaces
    Open Math. (IF 0.773) Pub Date : 2020-10-14
    Erdal Karapinar; Farshid Khojasteh; Zoran D. Mitrović; Vladimir Rakočević

    The aim of this paper is to establish some fixed point results for surrounding quasi-contractions in non-triangular metric spaces. Also, we prove the Banach principle of contraction in non-triangular metric spaces. As applications of our theorems, we deduce certain well-known results in b-metric spaces as corollaries.

  • Some inequalities for star duality of the radial Blaschke-Minkowski homomorphisms
    Open Math. (IF 0.773) Pub Date : 2020-10-14
    Xia Zhao; Weidong Wang; Youjiang Lin

    In 2006, Schuster introduced the radial Blaschke-Minkowski homomorphisms. In this article, associating with the star duality of star bodies and dual quermassintegrals, we establish Brunn-Minkowski inequalities and monotonic inequality for the radial Blaschke-Minkowski homomorphisms. In addition, we consider its Shephard-type problems and give a positive form and a negative answer, respectively.

  • Positive solutions for parametric ( p ( z ) , q ( z ) ) (p(z),q(z)) -equations
    Open Math. (IF 0.773) Pub Date : 2020-10-07
    Leszek Gasiński; Ireneusz Krech; Nikolaos S. Papageorgiou

    We consider a parametric elliptic equation driven by the anisotropic (p,q)-Laplacian. The reaction is superlinear. We prove a “bifurcation-type” theorem describing the change in the set of positive solutions as the parameter λ moves in ℝ+=(0,+∞).

  • Almost Kenmotsu 3-h-manifolds with transversely Killing-type Ricci operators
    Open Math. (IF 0.773) Pub Date : 2020-10-07
    Quanxiang Pan; Hui Wu; Yajie Wang

    In this paper, it is proved that the Ricci operator of an almost Kenmotsu 3-h-manifold M is of transversely Killing-type if and only if M is locally isometric to the hyperbolic 3-space ℍ3(−1) or a non-unimodular Lie group endowed with a left invariant non-Kenmotsu almost Kenmotsu structure. This result extends those results obtained by Cho [Local symmetry on almost Kenmotsu three-manifolds, Hokkaido

  • Generalized Picone inequalities and their applications to (p,q)-Laplace equations
    Open Math. (IF 0.773) Pub Date : 2020-09-30
    Vladimir Bobkov; Mieko Tanaka

    We obtain a generalization of the Picone inequality which, in combination with the classical Picone inequality, appears to be useful for problems with the (p,q)-Laplace-type operators. With its help, as well as with the help of several other known generalized Picone inequalities, we provide some nontrivial facts on the existence and nonexistence of positive solutions to the zero Dirichlet problem for

  • Detectable sensation of a stochastic smoking model
    Open Math. (IF 0.773) Pub Date : 2020-09-26
    Abdullah Alzahrani; Anwar Zeb

    This paper is related to the stochastic smoking model for the purpose of creating the effects of smoking that are not observed in deterministic form. First, formulation of the stochastic model is presented. Then the sufficient conditions for extinction and persistence are determined. Furthermore, the threshold of the proposed stochastic model is discussed, when noises are small or large. Finally, the

  • Sharper existence and uniqueness results for solutions to fourth-order boundary value problems and elastic beam analysis
    Open Math. (IF 0.773) Pub Date : 2020-09-28
    Saleh S. Almuthaybiri; Christopher C. Tisdell

    We examine the existence and uniqueness of solutions to two-point boundary value problems involving fourth-order, ordinary differential equations. Such problems have interesting applications to modelling the deflections of beams. We sharpen traditional results by showing that a larger class of problems admit a unique solution. We achieve this by drawing on fixed-point theory in an interesting and alternative

  • Remark on subgroup intersection graph of finite abelian groups
    Open Math. (IF 0.773) Pub Date : 2020-09-18
    Jinxing Zhao; Guixin Deng

    Let G be a finite group. The subgroup intersection graph Γ(G) of G is a graph whose vertices are non-identity elements of G and two distinct vertices x and y are adjacent if and only if |〈x〉∩〈y〉|>1, where 〈x〉 is the cyclic subgroup of G generated by x. In this paper, we show that two finite abelian groups are isomorphic if and only if their subgroup intersection graphs are isomorphic.

  • A new approach in the context of ordered incomplete partial b-metric spaces
    Open Math. (IF 0.773) Pub Date : 2020-09-19
    Tawseef Rashid; Mohammed M. M. Jaradat; Qamrul Haq Khan; Zoran D. Mitrović; Hassen Aydi; Zead Mustafa

    The main purpose of this paper is to find some fixed point results with a new approach, particularly in those cases where the existing literature remains silent. More precisely, we introduce partial completeness, f̄-orbitally completeness, a new type of contractions and many other notions. We also ensure the existence of fixed points for non-contraction maps in the class of incomplete partial b-metric

  • General (p,q)-mixed projection bodies
    Open Math. (IF 0.773) Pub Date : 2020-09-15
    Yibin Feng; Yanping Zhou

    In this article, the general (p,q)-mixed projection bodies are introduced. Then, some basic properties of the general (p,q)-mixed projection bodies are discussed, and the extreme values of volumes of the general (p,q)-mixed projection bodies and their polar bodies are established.

  • Some non-commuting solutions of the Yang-Baxter-like matrix equation
    Open Math. (IF 0.773) Pub Date : 2020-09-15
    Duan-Mei Zhou; Hong-Quang Vu

    Let A be a square matrix satisfying A4=A. We solve the Yang-Baxter-like matrix equation AXA=XAX to find some solutions, based on analysis of the characteristic polynomial of A and its eigenvalues. We divide the problem into small cases so that we can find the solution easily. Finally, in order to illustrate the results, two numerical examples are presented.

  • An extension of the method of brackets. Part 2
    Open Math. (IF 0.773) Pub Date : 2020-09-16
    Ivan Gonzalez; Lin Jiu; Victor H. Moll

    The method of brackets, developed in the context of evaluation of integrals coming from Feynman diagrams, is a procedure to evaluate definite integrals over the half-line. This method consists of a small number of operational rules devoted to convert the integral into a bracket series. A second small set of rules evaluates this bracket series and produces the result as a regular series. The work presented

  • Asymptotic normality and mean consistency of LS estimators in the errors-in-variables model with dependent errors
    Open Math. (IF 0.773) Pub Date : 2020-09-09
    Yu Zhang; Xinsheng Liu; Yuncai Yu; Hongchang Hu

    In this article, an errors-in-variables regression model in which the errors are negatively superadditive dependent (NSD) random variables is studied. First, the Marcinkiewicz-type strong law of large numbers for NSD random variables is established. Then, we use the strong law of large numbers to investigate the asymptotic normality of least square (LS) estimators for the unknown parameters. In addition

  • Nonlinear boundary value problems for mixed-type fractional equations and Ulam-Hyers stability
    Open Math. (IF 0.773) Pub Date : 2020-09-10
    Huiwen Wang; Fang Li

    In this article, we discuss the nonlinear boundary value problems involving both left Riemann-Liouville and right Caputo-type fractional derivatives. By using some new techniques and properties of the Mittag-Leffler functions, we introduce a formula of the solutions for the aforementioned problems, which can be regarded as a novelty item. Moreover, we obtain the existence result of solutions for the

  • A new characterization of L 2 ( p 2 ) {L}_{2}({p}^{2})
    Open Math. (IF 0.773) Pub Date : 2020-09-03
    Zhongbi Wang; Chao Qin; Heng Lv; Yanxiong Yan; Guiyun Chen

    For a positive integer n and a prime p, let np denote the p-part of n. Let G be a group, cd(G) the set of all irreducible character degrees of G, ρ(G) the set of all prime divisors of integers in cd(G), V(G)=pep(G)|p∈ρ(G), where pep(G)=max{χ(1)p|χ∈Irr(G)}. In this article, it is proved that G≅L2(p2) if and only if |G|=|L2(p2)| and V(G)=V(L2(p2)).

  • A systolic inequality with remainder in the real projective plane
    Open Math. (IF 0.773) Pub Date : 2020-08-24
    Mikhail G. Katz; Tahl Nowik

    The first paper in systolic geometry was published by Loewner’s student P. M. Pu over half a century ago. Pu proved an inequality relating the systole and the area of an arbitrary metric in the real projective plane. We prove a stronger version of Pu’s systolic inequality with a remainder term.

  • Jordan {g,h}-derivations on triangular algebras
    Open Math. (IF 0.773) Pub Date : 2020-08-24
    Liang Kong; Jianhua Zhang

    In this article, we give a sufficient and necessary condition for every Jordan {g,h}-derivation to be a {g,h}-derivation on triangular algebras. As an application, we prove that every Jordan {g,h}-derivation on τ(N) is a {g,h}-derivation if and only if dim0+≠1 or dimH−⊥≠1, where N is a non-trivial nest on a complex separable Hilbert space H and τ(N) is the associated nest algebra.

  • Bipartite graphs with close domination and k-domination numbers
    Open Math. (IF 0.773) Pub Date : 2020-08-24
    Gülnaz Boruzanlı Ekinci; Csilla Bujtás

    Let k be a positive integer and let G be a graph with vertex set V(G). A subset D⊆V(G) is a k-dominating set if every vertex outside D is adjacent to at least k vertices in D. The k-domination number γk(G) is the minimum cardinality of a k-dominating set in G. For any graph G, we know that γk(G)≥γ(G)+k−2 where Δ(G)≥k≥2 and this bound is sharp for every k≥2. In this paper, we characterize bipartite

  • Asymptotic relations for the products of elements of some positive sequences
    Open Math. (IF 0.773) Pub Date : 2020-08-04
    Agata Chmielowska; Michał Różański; Barbara Smoleń; Ireneusz Sobstyl; Roman Wituła

    The aim of this study was to present a simple method for finding the asymptotic relations for products of elements of some positive real sequences. The main reason to carry out this study was the result obtained by Alzer and Sandor concerning an estimation of a sequence of the product of the first k primes.

  • Positive coincidence points for a class of nonlinear operators and their applications to matrix equations
    Open Math. (IF 0.773) Pub Date : 2020-08-04
    Imed Kedim; Maher Berzig; Ahdi Noomen Ajmi

    Consider an ordered Banach space and f,g two self-operators defined on the interior of its positive cone. In this article, we prove that the equation f(X)=g(X) has a positive solution, whenever f is strictly α-concave g-monotone or strictly (−α)-convex g-antitone with g super-homogeneous and surjective. As applications, we show the existence of positive definite solutions to new classes of nonlinear

  • On a functional equation that has the quadratic-multiplicative property
    Open Math. (IF 0.773) Pub Date : 2020-08-04
    Choonkil Park; Kandhasamy Tamilvanan; Ganapathy Balasubramanian; Batool Noori; Abbas Najati

    In this article, we obtain the general solution and prove the Hyers-Ulam stability of the following quadratic-multiplicative functional equation: ϕ(st−uv)+ϕ(sv+tu)=[ϕ(s)+ϕ(u)][ϕ(t)+ϕ(v)]by using the direct method and the fixed point method.

  • Karush-Kuhn-Tucker optimality conditions for a class of robust optimization problems with an interval-valued objective function
    Open Math. (IF 0.773) Pub Date : 2020-07-22
    Jing Zhao; Maojun Bin

    In this article, we study the nonlinear and nonsmooth interval-valued optimization problems in the face of data uncertainty, which are called interval-valued robust optimization problems (IVROPs). We introduce the concept of nondominated solutions for the IVROP. If the interval-valued objective function f and constraint functions gi are nonsmooth on Banach space E, we establish a nonsmooth and robust

  • Tiny zero-sum sequences over some special groups
    Open Math. (IF 0.773) Pub Date : 2020-07-27
    Linlin Wang

    Let S=g1⋅…⋅gn be a sequence with elements gi from an additive finite abelian group G. S is called a tiny zero-sum sequence if S is non-empty, g1+…+gn=0 and k(S)≔∑i=1n1ord(gi)≤1. Let t(G) be the smallest integer t such that every sequence of t elements (repetition allowed) from G contains a tiny zero-sum sequence. In this article, we mainly focus on the explicit value of t(G) and compute this value

  • The spectrum generated by s-numbers and pre-quasi normed Orlicz-Cesáro mean sequence spaces
    Open Math. (IF 0.773) Pub Date : 2020-07-29
    Awad A. Bakery

    In this article, we study some topological properties of the multiplication operator on Orlicz-Cesáro mean sequence spaces equipped with the pre-quasi norm and the pre-quasi operator ideal constructed by this sequence space and s-numbers.

  • A boundedness result for Marcinkiewicz integral operator
    Open Math. (IF 0.773) Pub Date : 2020-07-29
    Laith Hawawsheh; Mohammad Abudayah

    We extend a boundedness result for Marcinkiewicz integral operator. We find a new space of radial functions for which this class of singular integral operators remains Lp-bounded when its kernel satisfies only the sole integrability condition.

  • Sequential change-point detection in a multinomial logistic regression model
    Open Math. (IF 0.773) Pub Date : 2020-07-29
    Fuxiao Li; Zhanshou Chen; Yanting Xiao

    Change-point detection in categorical time series has recently gained attention as statistical models incorporating change-points are common in practice, especially in the area of biomedicine. In this article, we propose a sequential change-point detection procedure based on the partial likelihood score process for the detection of changes in the coefficients of multinomial logistic regression model

  • The H-force sets of the graphs satisfying the condition of Ore’s theorem
    Open Math. (IF 0.773) Pub Date : 2020-07-21
    Xinhong Zhang; Ruijuan Li

    Let G be a Hamiltonian graph. A nonempty vertex set X⊆V(G) is called a Hamiltonian cycle enforcing set (in short, an H-force set) of G if every X-cycle of G (i.e., a cycle of G containing all vertices of X) is a Hamiltonian cycle. For the graph G, h(G) (called the H-force number of G) is the smallest cardinality of an H-force set of G. Ore’s theorem states that an n-vertex graph G is Hamiltonian if

  • Generalized fractional integral inequalities of Hermite-Hadamard-type for a convex function
    Open Math. (IF 0.773) Pub Date : 2020-07-22
    Jiangfeng Han; Pshtiwan Othman Mohammed; Huidan Zeng

    The primary objective of this research is to establish the generalized fractional integral inequalities of Hermite-Hadamard-type for MT-convex functions and to explore some new Hermite-Hadamard-type inequalities in a form of Riemann-Liouville fractional integrals as well as classical integrals. It is worth mentioning that our work generalizes and extends the results appeared in the literature.

  • Curves in the Lorentz-Minkowski plane with curvature depending on their position
    Open Math. (IF 0.773) Pub Date : 2020-07-22
    Ildefonso Castro; Ildefonso Castro-Infantes; Jesús Castro-Infantes

    Motivated by the classical Euler elastic curves, David A. Singer posed in 1999 the problem of determining a plane curve whose curvature is given in terms of its position. We propound the same question in the Lorentz-Minkowski plane, focusing on spacelike and timelike curves. In this article, we study those curves in L2 whose curvature depends on the Lorentzian pseudodistance from the origin, and those

  • An efficient approach for the numerical solution of fifth-order KdV equations
    Open Math. (IF 0.773) Pub Date : 2020-07-22
    Hijaz Ahmad; Tufail A. Khan; Shao-Wen Yao

    The main aim of this article is to use a new and simple algorithm namely the modified variational iteration algorithm-II (MVIA-II) to obtain numerical solutions of different types of fifth-order Korteweg-de Vries (KdV) equations. In order to assess the precision, stability and accuracy of the solutions, five test problems are offered for different types of fifth-order KdV equations. Numerical results

  • Levinson-type inequalities via new Green functions and Montgomery identity
    Open Math. (IF 0.773) Pub Date : 2020-07-01
    Muhammad Adeel; Khuram Ali Khan; Ðilda Pečarić; Josip Pečarić

    In this study, Levinson-type inequalities are generalized by using new Green functions and Montgomery identity for the class of k-convex functions (k ≥ 3). Čebyšev-, Grüss- and Ostrowski-type new bounds are found for the functionals involving data points of two types. Moreover, a new functional is introduced based on f divergence and then some estimates for new functional are obtained. Some inequalities

  • Controllability of fractional stochastic evolution equations with nonlocal conditions and noncompact semigroups
    Open Math. (IF 0.773) Pub Date : 2020-07-02
    Yonghong Ding; Yongxiang Li

    This article deals with the exact controllability for a class of fractional stochastic evolution equations with nonlocal initial conditions in a Hilbert space under the assumption that the semigroup generated by the linear part is noncompact. Our main results are obtained by utilizing stochastic analysis technique, measure of noncompactness and the Mönch fixed point theorem. In the end, an example

  • A pair of equations in unlike powers of primes and powers of 2
    Open Math. (IF 0.773) Pub Date : 2020-07-06
    Yong Cai; Liqun Hu

    In this article, we show that every pair of large even integers satisfying some necessary conditions can be represented in the form of a pair of one prime, one prime squares, two prime cubes, and 187 powers of 2.

  • The core inverse and constrained matrix approximation problem
    Open Math. (IF 0.773) Pub Date : 2020-07-06
    Hongxing Wang; Xiaoyan Zhang

    In this article, we study the constrained matrix approximation problem in the Frobenius norm by using the core inverse: ||Mx−b||F=minsubjecttox∈ℛ(M),where M∈ℂnCM. We get the unique solution to the problem, provide two Cramer’s rules for the unique solution and establish two new expressions for the core inverse.

  • B-maximal commutators, commutators of B-singular integral operators and B-Riesz potentials on B-Morrey spaces
    Open Math. (IF 0.773) Pub Date : 2020-07-10
    Javanshir J. Hasanov; Rabil Ayazoglu; Simten Bayrakci

    In this article, we consider the Laplace-Bessel differential operator ΔBk,n=∑i=1k∂2∂xi2+γixi∂∂xi+∑i=k+1n∂2∂xi2,γ1>0,…,γk>0.

  • Miscellaneous equalities for idempotent matrices with applications
    Open Math. (IF 0.773) Pub Date : 2020-07-17
    Yongge Tian

    This article brings together miscellaneous formulas and facts on matrix expressions that are composed by idempotent matrices in one place with cogent introduction and references for further study. The author will present the basic mathematical ideas and methodologies of the matrix analytic theory in a readable, up-to-date, and comprehensive manner, including constructions of various algebraic matrix

  • Rate of convergence of uniform transport processes to a Brownian sheet
    Open Math. (IF 0.773) Pub Date : 2020-07-19
    Carles Rovira

    We give the rate of convergence to a Brownian sheet from a family of processes constructed starting from a set of independent standard Poisson processes. These processes have realizations that converge almost surely to the Brownian sheet, uniformly in the unit square.

  • Inverse Sturm-Liouville problem with analytical functions in the boundary condition
    Open Math. (IF 0.773) Pub Date : 2020-06-10
    Natalia Pavlovna Bondarenko

    The inverse spectral problem is studied for the Sturm-Liouville operator with a complex-valued potential and arbitrary entire functions in one of the boundary conditions. We obtain necessary and sufficient conditions for uniqueness and develop a constructive algorithm for the inverse problem solution. The main results are applied to the Hochstadt-Lieberman half-inverse problem. As an auxiliary proposition

  • On the well-posedness of differential quasi-variational-hemivariational inequalities
    Open Math. (IF 0.773) Pub Date : 2020-06-11
    Jinxia Cen; Chao Min; Van Thien Nguyen; Guo-ji Tang

    The goal of this paper is to discuss the well-posedness and the generalized well-posedness of a new kind of differential quasi-variational-hemivariational inequality (DQHVI) in Hilbert spaces. Employing these concepts, we explore the essential relation between metric characterizations and the well-posedness of DQHVI. Moreover, the compactness of the set of solutions for DQHVI is delivered, when problem

  • Left and right inverse eigenpairs problem with a submatrix constraint for the generalized centrosymmetric matrix
    Open Math. (IF 0.773) Pub Date : 2020-06-18
    Fan-Liang Li

    Left and right inverse eigenpairs problem is a special inverse eigenvalue problem. There are many meaningful results about this problem. However, few authors have considered the left and right inverse eigenpairs problem with a submatrix constraint. In this article, we will consider the left and right inverse eigenpairs problem with the leading principal submatrix constraint for the generalized centrosymmetric

  • Global structure of sign-changing solutions for discrete Dirichlet problems
    Open Math. (IF 0.773) Pub Date : 2020-06-18
    Liping Wei; Ruyun Ma

    Let T>1 be an integer, T≔[1,T]Z={1,2,…,T},Tˆ≔{0,1,…,T+1}. In this article, we are concerned with the global structure of the set of sign-changing solutions of the discrete second-order boundary value problem {Δ2u(x−1)+λh(x)f(u(x))=0,x∈T,u(0)=u(T+1)=0,where λ>0 is a parameter, f∈C(ℝ,ℝ) satisfies f(0)=0,sf(s)>0 for all s≠0 and h:Tˆ→[0,+∞). By using the directions of a bifurcation, we obtain existence

  • The L-ordered L-semihypergroups
    Open Math. (IF 0.773) Pub Date : 2020-06-20
    Shuhua Su; Fuyao Liu; Shuqun Yang

    This study pursues an investigation on L-semihypergroups equipped with an L-order. First, the concept of L-ordered L-semihypergroups is introduced by L-posets and L-semihypergroups, and some related results are obtained. Then, prime, weakly prime, and semiprime L-hyperideals of L-ordered L-semihypergroups are studied. Moreover, the relationships among the three types of L-hyperideals are established

  • On finite dual Cayley graphs
    Open Math. (IF 0.773) Pub Date : 2020-06-22
    Jiangmin Pan

    A Cayley graph Γ on a group G is called a dual Cayley graph on G if the left regular representation of G is a subgroup of the automorphism group of Γ (note that the right regular representation of G is always an automorphism group of Γ). In this article, we study finite dual Cayley graphs regarding identification, construction, transitivity and such graphs with automorphism groups as small as possible

  • Analysis of F-contractions in function weighted metric spaces with an application
    Open Math. (IF 0.773) Pub Date : 2020-06-22
    Zhenhua Ma; Awais Asif; Hassen Aydi; Sami Ullah Khan; Muhammad Arshad

    In this work, we show that the existence of fixed points of F-contraction mappings in function weighted metric spaces can be ensured without third condition (F3) imposed on Wardowski function F:(0, ∞)→ℜ. The present article investigates (common) fixed points of rational type F-contractions for single-valued mappings. The article employs Jleli and Samet’s perspective of a new generalization of a metric

  • On the finite approximate controllability for Hilfer fractional evolution systems with nonlocal conditions
    Open Math. (IF 0.773) Pub Date : 2020-06-10
    Xianghu Liu

    The aim of this study is to investigate the finite approximate controllability of certain Hilfer fractional evolution systems with nonlocal conditions. To achieve this, we first transform the mild solution of the Hilfer fractional evolution system into a fixed point problem for a condensing map. Then, by using the topological degree approach, we present sufficient conditions for the existence and uniqueness

  • Weighted CBMO estimates for commutators of matrix Hausdorff operator on the Heisenberg group
    Open Math. (IF 0.773) Pub Date : 2020-06-04
    Amna Ajaib; Amjad Hussain

    In this article, we study the commutators of Hausdorff operators and establish their boundedness on the weighted Herz spaces in the setting of the Heisenberg group.

  • Discussions on the almost Z{\mathcal{Z}}-contraction
    Open Math. (IF 0.773) Pub Date : 2020-06-04
    Erdal Karapınar; V. M. L. Hima Bindu

    In this paper, we introduce a new contraction, namely, almost Z contraction with respect to ζ∈Z, in the setting of complete metric spaces. We proved that such contraction possesses a fixed point and the given theorem covers several existing results in the literature. We consider an example to illustrate our result.

  • On the N-spectrum of oriented graphs
    Open Math. (IF 0.773) Pub Date : 2020-06-04
    Mohammad Abudayah; Omar Alomari; Torsten Sander

    Given any digraph D, its non-negative spectrum (or N-spectrum, shortly) consists of the eigenvalues of the matrix AAT, where A is the adjacency matrix of D. In this study, we relate the classical spectrum of undirected graphs to the N-spectrum of their oriented counterparts, permitting us to derive spectral bounds. Moreover, we study the spectral effects caused by certain modifications of a given digraph

  • On split involutive regular BiHom-Lie superalgebras
    Open Math. (IF 0.773) Pub Date : 2020-06-04
    Shuangjian Guo; Xiaohui Zhang; Shengxiang Wang

    The goal of this paper is to examine the structure of split involutive regular BiHom-Lie superalgebras, which can be viewed as the natural generalization of split involutive regular Hom-Lie algebras and split regular BiHom-Lie superalgebras. By developing techniques of connections of roots for this kind of algebras, we show that such a split involutive regular BiHom-Lie superalgebra L is of the form

  • On a predator-prey system interaction under fluctuating water level with nonselective harvesting
    Open Math. (IF 0.773) Pub Date : 2020-06-04
    Na Zhang; Yonggui Kao; Fengde Chen; Binfeng Xie; Shiyu Li

    A predator-prey model interaction under fluctuating water level with non-selective harvesting is proposed and studied in this paper. Sufficient conditions for the permanence of two populations and the extinction of predator population are provided. The non-negative equilibrium points are given, and their stability is studied by using the Jacobian matrix. By constructing a suitable Lyapunov function

  • Two types of hypergeometric degenerate Cauchy numbers
    Open Math. (IF 0.773) Pub Date : 2020-05-29
    Takao Komatsu

    In 1985, Howard introduced degenerate Cauchy polynomials together with degenerate Bernoulli polynomials. His degenerate Bernoulli polynomials have been studied by many authors, but his degenerate Cauchy polynomials have been forgotten. In this paper, we introduce some kinds of hypergeometric degenerate Cauchy numbers and polynomials from the different viewpoints. By studying the properties of the first

  • On the Malcev products of some classes of epigroups, I
    Open Math. (IF 0.773) Pub Date : 2020-05-29
    Jingguo Liu

    A semigroup is called an epigroup if some power of each element lies in a subgroup. Under the universal of epigroups, the aim of the paper is devoted to presenting elements in the groupoid together with the multiplication of Malcev products generated by classes of completely simple semigroups, nil-semigroups and semilattices. The information about the set inclusion relations among them is also provided

  • Approximation operators based on preconcepts
    Open Math. (IF 0.773) Pub Date : 2020-05-28
    Gang Wang; Hua Mao

    Using the notion of preconcept, we generalize Pawlak’s approximation operators from a one-dimensional space to a two-dimensional space in a formal context. In a formal context, we present two groups of approximation operators in a two-dimensional space: one is aided by an equivalence relation defined on the attribute set, and another is aided by the lattice theoretical property of the family of preconcepts

  • The molecular characterization of anisotropic Herz-type Hardy spaces with two variable exponents
    Open Math. (IF 0.773) Pub Date : 2020-05-28
    Qingdong Guo; Wenhua Wang

    In this article, the authors establish the characterizations of a class of anisotropic Herz-type Hardy spaces with two variable exponents associated with a non-isotropic dilation on ℝn in terms of molecular decompositions. Using the molecular decompositions, the authors obtain the boundedness of the central δ-Calderón-Zygmund operators on the anisotropic Herz-type Hardy space with two variable exponents

  • Some results in cone metric spaces with applications in homotopy theory
    Open Math. (IF 0.773) Pub Date : 2020-05-28
    Muhammad Nazam; Anam Arif; Hasan Mahmood; Choonkil Park

    The self-mappings satisfying implicit relations were introduced in a previous study [Popa, Fixed point theorems for implicit contractive mappings, Stud. Cerc. St. Ser. Mat. Univ. Bacău 7 (1997), 129–133]. In this study, we introduce self-operators satisfying an ordered implicit relation and hence obtain their fixed points in the cone metric space under some additional conditions. We obtain a homotopy

  • On multivalued Suzuki-type θ-contractions and related applications
    Open Math. (IF 0.773) Pub Date : 2020-05-26
    Amjad Ali; Hüseyin Işık; Hassen Aydi; Eskandar Ameer; Jung Rye Lee; Muhammad Arshad

    In this study, we develop the concept of multivalued Suzuki-type θ-contractions via a gauge function and established two new related fixed point theorems on metric spaces. We also discuss an example to validate our results.

  • On the symmetrized s-divergence
    Open Math. (IF 0.773) Pub Date : 2020-05-26
    Slavko Simić; Sara Salem Alzaid; Hassen Aydi

    In this study, we work with the relative divergence of type s,s∈ℝ, which includes the Kullback-Leibler divergence and the Hellinger and χ2 distances as particular cases. We study the symmetrized divergences in additive and multiplicative forms. Some basic properties such as symmetry, monotonicity and log-convexity are established. An important result from the convexity theory is also proved.

  • Cauchy matrix and Liouville formula of quaternion impulsive dynamic equations on time scales
    Open Math. (IF 0.773) Pub Date : 2020-05-26
    Zhien Li; Chao Wang

    In this study, we obtain the scalar and matrix exponential functions through a series of quaternion-valued functions on time scales. A sufficient and necessary condition is established to guarantee that the induced matrix is real-valued for the complex adjoint matrix of a quaternion matrix. Moreover, the Cauchy matrices and Liouville formulas for the quaternion homogeneous and nonhomogeneous impulsive

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