Utilitas Algorithmica (UA)

ISSN: xxxx-xxxx (print)

Utilitas Algorithmica (UA) is a premier, open-access international journal dedicated to advancing algorithmic research and its applications. Launched to drive innovation in computer science, UA publishes high-impact theoretical and experimental papers addressing real-world computational challenges. The journal underscores the vital role of efficient algorithm design in navigating the growing complexity of modern applications. Spanning domains such as parallel computing, computational geometry, artificial intelligence, and data structures, UA is a leading venue for groundbreaking algorithmic studies.

Indra Rajasingh1, R. Sundara Rajan2, Rajesh M3, Paul Manuel3
1School of Advanced Sciences, VIT University, Chennai, India
2School of Computing Sciences and Engineering, VIT University, Chennai, India
3Department of Information Sciences, Kuwait University, Safat, Kuwait
Abstract:

A grid is a large-scale geographically distributed hardware and software infrastructure composed of heterogeneous networked resources owned and shared by multiple administrative organizations which are coordinated to provide transparent, dependable, pervasive and consistent computing support to a wide range of applications. One of the major problems in graph theory is to find the oriented diameter of a graph \(G\), which is defined as the smallest diameter among the diameter of all strongly connected orientations. The problem is proved to be NP-complete. In this paper, we obtain the oriented diameter of grids.

V. Yegnanarayanan1, P. Vaidhyanathan2,
1Department of Sciences and Humanities, Vignan University, Andrapradesh, 522213, India
2Department of Mathematics, Bharathiyar University, Coimbatore, India
Abstract:

By a \((1,1)\) edge-magic labeling of a graph \( G(V, E) \), we mean a bijection \( f \) from \( V \cup E \) to \(\{1, \dots, |V| + |E|\}\) such that for all edges \( uv \in E(G) \), the value \( f(u) + f(v) + f(uv) \) is constant. We provide a different proof of a well-known result in additive number theory by Paul Erdős and, interestingly, demonstrate a practical application of this result. Additionally, we make some progress using computational methods towards the conjecture proposed by Yegnanarayanan: “Every graph on \( p \geq 9 \) vertices can be embedded as a subgraph of some \((1,1)\) edge-magic graph” raised by Yegnanarayanan.

N. JayanthKarthik1, E. Chandrasekaran2, R. Sattanathan3
1Department of Mathematics, D.G. Vaishnav College, Chennai, India.
2Department of Mathematics, Presidency College,Chennai, India.
3Posthumous, Department of Mathematics, D.G. Vaishnav College, Chennai, India.
Abstract:

In this paper, an \( n \times n \) fully fuzzy linear system is solved by decomposing the positive definite symmetric coefficient matrix using trapezoidal fuzzy number matrices through Cholesky and LDLT decomposition methods. The effectiveness of these methods is illustrated with a numerical example.

S. Roy1, Albert William1
1Department of Mathematics Loyola College, Chennai 600 034, India
Abstract:

Given an undirected 2-edge connected graph, finding a minimum 2-edge connected spanning subgraph is NP-hard. We solve the problem for Butterfly network, Benes network, Honeycomb network and Sierpiński gasket graph.

J. Baskar Babujee1, J. Senbagamalar1
1Department of Mathematics Anna University, Chennai – 600 025, India.
Abstract:

The Terminal Wiener index \( TW(G) \) of a graph \( G \) is defined as the sum of the distances between all pairs of pendant vertices. In this paper, we derive an explicit formula for calculating the Terminal Wiener index for Detour-saturated trees and Nanostar Dendrimers.

Bharati Rajan1, Albert William2, S. Prabhu3
1Department of Mathematics, Loyola College, Chennai, India
2School of Electrical Engineering and Computer Science, The University of Newcastle, NSW 2308, Australia
3Department of Mathematics, Velammal Institute of Technology, Chennai, India
Abstract:

Let \(G(V,E)\) be a graph. A set \(W \subset V\) of vertices resolves a graph \(G\) if every vertex of \(G\) is uniquely determined by its vector of distances to the vertices in \(W\). The metric dimension of \(G\) is the minimum cardinality of a resolving set. By imposing conditions on \(W\) we get conditional resolving sets.

R. Arundhadhi1, K. Thirusangu2
1Assistant Professor, Department of Mathematics, D.G. Vaishnav college, Arumbakkam, Chennai-600106.
2Associate Professor, Department of Mathematics, SIVET college, Gowriwakkam, Chennai-600 073.
Abstract:

A proper vertex coloring (no two adjacent vertices have the same color) of a graph \( G \) is said to be acyclic if the induced subgraph of any two color classes is acyclic. The minimum number of colors required for an acyclic coloring of a graph \( G \) is called its acyclic chromatic number and is denoted by \( a(G) \). In this paper, we determine the exact value of the acyclic chromatic number for the central and total graphs of the path \( P_n \), and the Fan graph \( F_{m,n} \).

Sudeep Stephen1, Bharati Rajan2, Mirka Miller3, Cyriac Grigorious4, Albert William5
1Department of Mathematics, Loyola College, Chennai, India
2School of Electrical Engineering and Computer Science, The University of Newcastle, Australia
3School of Mathematical and Physical Sciences, The University of Newcastle, Australia
4Department of Mathematics, University of West Bohemia, Pilsen, Czech Republic
5Department of Informatics, King’s College London, UK
Abstract:

Eigenvalues of a graph are the eigenvalues of its adjacency matrix. The multiset of eigenvalues is called the \({spectrum}\). The energy of a graph is defined as the sum of the absolute values of its eigenvalues. In this paper, we devise an algorithm that generates the adjacency matrix of \( WK \)-recursive structures \( WK(3, L) \) and \( WK(4, L) \), and use it to effectively compute the spectrum and energy of these graphs.

V. Yegnanarayanan1, V. Thamaraiselvi2
1Prof and HOD, Science and Humanities, Vignan University, Guntur -522213, India.
2Department of Mathematics, Bharathiyar University, Coimbatore.
Abstract:

Given a connected \((p, q)\) graph with a number of central vertices, form a new graph \(G^*\) as follows: \(V(G^*) = V(G)\); Delete all the edges of \(G\). Introduce an edge between every central vertex to each and every non-central vertex of \(G\); allow every pair of central vertices to be adjacent. In this paper, we probed \(G^*\) and deduced a number of results.

Abdullah Al Mutairi1, Bader Ali 1, Paul Manuel1
1Department of Information Science, College of Computing Science and Engineering, Kuwait University
Abstract:

Structures realized by arrangements of regular hexagons in the plane are of interest in the chemistry of benzenoid hydrocarbons, where perfect matchings correspond to Kekulé structures which feature in the calculation of molecular energies associated with benzenoid hydrocarbon molecules. Mathematically, assembling in predictable patterns is equivalent to packing in graphs. An \( H \)-packing of a graph \( G \) is a set of vertex-disjoint subgraphs of \( G \), each of which is isomorphic to a fixed graph \( H \). If \( H \) is the complete graph \( K_2 \), the maximum \( H \)-packing problem becomes the familiar maximum matching problem. In this paper, we find an \( H \)-packing of an armchair carbon nanotube with \( H \) isomorphic to \( P_4 \), \emph{1, 4-dimethyl cyclohexane}, and \( C_6 \). Further, we determine the \( H \)-packing of a zigzag carbon nanotube with \( H \) isomorphic to \emph{1, 4-dimethyl cyclohexane}.

Special Issues

The Combinatorial Press Editorial Office routinely extends invitations to scholars for the guest editing of Special Issues, focusing on topics of interest to the scientific community. We actively encourage proposals from our readers and authors, directly submitted to us, encompassing subjects within their respective fields of expertise. The Editorial Team, in conjunction with the Editor-in-Chief, will supervise the appointment of Guest Editors and scrutinize Special Issue proposals to ensure content relevance and appropriateness for the journal. To propose a Special Issue, kindly complete all required information for submission;