https://www.revistaproyecciones.cl/index.php/proyecciones/issue/feedProyecciones (Antofagasta, On line)2024-06-17T00:00:00+00:00Ricardo Soto Monterorsoto@ucn.clOpen Journal Systems<p align="justify">La revista Proyecciones. Journal of Mathematics es una publicación científica, sin fines de lucro, oficial de la Universidad Católica del Norte, Antofagasta, Chile. Fue fundada en 1982 y depende del Departamento de Matemáticas de la Universidad Católica del Norte.<br>Proyecciones. Journal of Mathematics edita un volumen con 5 números al año.</p>https://www.revistaproyecciones.cl/index.php/proyecciones/article/view/5477Pairwise Infra Neutrosophic Pre-Open Set in Infra Neutrosophic Bi-topological Space2022-06-12T12:38:11+00:00Suman Dassumandas18842@gmail.comRakhal Dasrakhaldas95@gmail.com<p>In this article, we present the notion of infra neutrosophic bi-topological spaces (in short INBTS) as a generalization of infra neutrosophic topological space (in short INTS) and neutrosophic bi-topological space (in short NBTS). Besides, we study the different types of open and closed sets namely infra neutrosophic bi-open set (in short INBOS), infra neutrosophic bi-semi-open set (in short INBSOS), infra neutrosophic bi-pre-open set (in short INBPOS), infra neutrosophic bi-<em>b</em>-open set (in short INB<em>b-</em>OS), etc. via INBTSs. Then, we introduce the notion of pairwise infra neutrosophic bi-open set (in short PINBOS), pairwise infra neutrosophic bi-semi-open set (in short PINBSOS), pairwise infra neutrosophic bi-pre-open set (in short PINBPOS), pairwise infra neutrosophic bi-<em>b</em>-open set (in short PINB<em>b</em>-OS), and furnish few illustrative examples on them. Further, we investigate several properties of these classes of sets and establish several interesting results via INBTSs in the form of propositions, theorems, etc.</p>2024-06-17T00:00:00+00:00Copyright (c) 2024 RAKHAL DAS, Suman Dashttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/6374Fixed point and stability of nonlinear differential equations with variable delays 2024-02-13T14:13:43+00:00Abdelhafid Younsiabehafidyounsi@gmail.com<p>In this paper, we study the stability of a generalized nonlinear differential equation with variable delays via fixed point theory. An asymptotic stability theorem with sufficient conditions is proved, which improves and generalizes some previous results. Two examples are given to illustrate our results.</p>2024-06-17T00:00:00+00:00Copyright (c) 2024 Abdelhafid younsihttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/6286Uniform stability, boundedness and square integrability for non-autonomous third-order neutral differential equations with delay2024-02-11T05:03:40+00:00Mebrouk Rahmanemeb.rahmane@univ-adrar.edu.dzFatima Abdellaouiabdellaouifatima11@gmail.com<p>The work in this article provides literature with some results concerning the exponential stability, the boundedness and the square integrability of solutions for some non autonomous equations of third order supplied with delay and neutral parameters. The main tool used in this work is the second method of Lyapunov. The article is finished by giving a concrete example that ensure the application of the obtained results.</p>2024-06-17T00:00:00+00:00Copyright (c) 2024 Mebrouk Rahmane, Fatima Abdellaouihttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/6376Singularity of cycle-spliced signed graphs2024-04-11T11:54:43+00:00Suliman Khansuliman.khan@unicampania.itAdriana Ciampellaciampell@unina.it<p>We consider the adjacency spectrum of cycle-spliced signed graphs (CSSG), i.e., signed graphs whose blocks are (independent) signed cycles. For a signed graph Σ, the nullity η(Σ) is the multiplicity of the 0-eigenvalue. The adjancency spectrum of cycle-spliced (signed) graphs is studied in the literature for the relation between the nullity η and the cyclomatic number c, in particular, it is known that 0≤η(Σ) ≤ c(Σ)+1. In this paper, nonsingular cycle-spliced bipartite signed graphs are characterized. For cycle-spliced signed graphs Σ having only odd cycles, we show that η(Σ) is 0 or 1. Finally, we compute the nullity of CSSGs consisting of at most three cycles.</p>2024-06-17T00:00:00+00:00Copyright (c) 2024 Adriana Ciampella, Suliman Khanhttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/6155Stability and boundedness of solutions of certain Lienard-type non-autonomous differential equations2024-05-04T18:05:29+00:00Abdullai Abdurasidabdurasid.abdullai@yahoo.comA. L. Olutimoaolutimo@yahoo.comM. O. Omeikemoomeike@yahoo.com<p>In this paper, the Liénard-type non-autonomous nonlinear differential equation</p> <p>ẍ+ p(t)f(x, ẋ) ẋ + q(t)g(x) = ϕ(t, x, ẋ)</p> <p>is investigated for uniform exponential asymptotic stability of solutions when ϕ(t, x, ẋ) ≡ 0, and uniform ultimate boundedness of solutions when ϕ(t, x, ẋ) ≠ 0, using the Lyapunov’s direct method</p>2024-06-17T00:00:00+00:00Copyright (c) 2024 Abdullai Abdurasid, Olutimo A.L., M. O. Omeikehttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/5962Coloring of Non-Zero Component Graphs2023-07-03T16:19:58+00:00Vrinda Mary Mathewvrinda.mathew@res.christuniversity.inSudev Naduvathsudevmath@gmail.com<p>The non-zero component graph of finite dimensional vector space <strong>V</strong> over a finite field <strong>F</strong> is the graph G(V<sub>α</sub>)= (V,E), where vertices of G(V<sub>α</sub>) are the non-zero vectors in <strong>V</strong>, two of which are adjacent if they share at least one basis vector with non-zero coefficient in their basic representation. In this paper, we study the various types of colorings of non-zero component graph.</p>2024-06-19T00:00:00+00:00Copyright (c) 2024 Vrinda, Sudev Naduvathhttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/6158A note on P-Sasakian manifolds satisfying certain conditions2024-02-29T02:31:56+00:00Pakize Uygunpakizeuygun@hotmail.comMehmet Atçekenmehmet.atceken382@gmail.com<p>In the present paper, we have studied the curvature tensors of PSasakian manifold. For a P-Sasakian manifold, W<sub>1</sub> ·S = 0, W<sub>1</sub> ·Z = 0 and W<sub>9</sub> · W<sub>1</sub> = 0 cases are considered. According these cases, PSasakian manifolds have been characterized such as η-Einstein and Einstein. In addition, we research W<sub>1</sub>-flat and W<sub>9</sub>-flat for a PSasakian manifold. The results are interesting and give an idea about the geometry of P-Sasakian manifold.</p>2024-06-19T00:00:00+00:00Copyright (c) 2024 pakize uygun, Mehmet Atcekenhttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/6174A study on deg-centric graphs2024-02-21T19:10:33+00:00Timmy Tomy Thalavayaliltimmy.thalavayalil@res.christuniversity.inJohan Kokjohan.kok@christuniversity.inSudev Naduvathsudevmath@gmail.com<p>The deg-centric graph of a simple, connected graph G, denoted by G<sub>d</sub>, is a graph constructed from G such that, V(G<sub>d</sub>) = V(G) and E(G<sub>d</sub>) = {v<sub>i</sub>v<sub>j</sub>: d<sub>G</sub>(v<sub>i</sub>,v<sub>j</sub>) ≤ deg<sub>G</sub>(v<sub>i</sub>)}. In this paper, the concepts of deg-centric graphs and iterated deg-centrication of a graph are introduced and discussed.</p>2024-06-24T00:00:00+00:00Copyright (c) 2024 Sudev Naduvath, Timmy, Johanhttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/5828Cayley fuzzy graphs on groups2023-04-01T10:46:42+00:00Mary John Jishajjmakm@gmail.comA. Riyasriyasmaths@gmail.comK. Geethageetha@tkmce.ac.in<p>We investigate some properties of Cayley fuzzy graphs on groups in terms of algebraic structures. And we also discuss the connectedness on it. In this paper, we prove that the Cayley fuzzy graph induced by (Z<sub>m</sub> × Z<sub>n</sub>, +, ν) is the disjoint union of Cay (aH, R) provided ν(h) > 0 ∀ h ∈ H and ν(h′) =0 ∀ h′∈ Z<sub>m</sub> × Z<sub>n</sub>\H, where H is the cyclic subgroup of order n in Z<sub>m</sub> × Z<sub>n</sub>.</p>2024-06-19T00:00:00+00:00Copyright (c) 2024 JISHA MARY JOHN KAIMALIL HOUSE, A RIYAS, K GEETHAhttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/5862On the right automorphic generalised Bol loops2023-01-25T06:55:45+00:00Abdulafeez Olalekan Abdulkareemafeezokareem@gmail.comY. T. Oyebooyeboyt@yahoo.comJ. O. Adeniranekenedilichineke@yahoo.com<p>This study centers on right automophic generalised Bol loops. Having established the generators of inner mapping group of generalised Bol loops, some properties of generalised Bol loops, in terms of right translation map, are obtained. These properties are later used to established a condition under which right automorphic generalised Bol loop is a generalised Moufang loop.</p>2024-06-24T00:00:00+00:00Copyright (c) 2024 Dr. Abdulkareem A.O., Y.T Oyebo, J. O. Adeniranhttps://www.revistaproyecciones.cl/index.php/proyecciones/article/view/6179Induced Dominating Sequence and ESD Graphs2024-01-08T17:05:04+00:00Liju Alexindulalgopal@gmail.comJohn Joy Mulloorindulalgopal@gmail.comIndulal Gopalapillaindulalgopal@gmail.com<p>A vertex subset D of a graph G = (V,E) is said to be a dominating set if every vertex in G is either in D or adjacent to some vertex in D. The minimum cardinality of such a set is the domination number, which is denoted as γ(G). In this paper, we define a sequence associated with the domination concept in graphs and studied the basic properties of the sequence in terms of various parameters of graphs. Using this sequence we order the vertices of a dominating set according its significance and propose Equally Significant Dominating (ESD) graphs. We also introduced domination related topological indices and compute their lower bounds for trees, unicyclic graphs and bicyclic graphs. All the graphs attaining the bounds are characterized.</p>2024-06-19T00:00:00+00:00Copyright (c) 2024 Indulal Gopalapilla, Liju Alex, John Joy https://www.revistaproyecciones.cl/index.php/proyecciones/article/view/6412A characterization of σ-prime rings involving generalized derivations2024-04-01T13:32:19+00:00Arshad Madniarshadmadni7613@gmail.comMuzibur Rahman Mozumdermuzibamu81@gmail.comWasim Ahmedwasim10041994@gmail.comAbu Zaid Ansariansari.abuzaid@gmail.com<p>This paper’s major goal is to work on commutativity of σ-prime rings with second kind involution σ, involving generalized derivation satisfy the certain differential identities. Finally, we provide some examples to demonstrate that the conditions assumed in our results are not unnecessary</p>2024-06-24T00:00:00+00:00Copyright (c) 2024 Wasim Ahmed, Md. Arshad Madni, Muzibur Rahman Mozumder, Abu Zaid Ansari