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.

Vasanti N.Bhat-Nayak1, A. Selvam2
1Department of Mathematics University of Mumbai Mumbai-400 098, India
2 Department of Mathematics Dr. Sivanthi.Aditanar College of Engineering Tiruchendur-628 215, India.
Abstract:

It is proved that the \(n\)-cone \(C_m \vee K_n^c\) is graceful for any \(n \geq 1\) and \(m = 0\) or \(3 \pmod{12}\). The gracefulness of the following \(n\)-cones is also established: \(C_4 \vee K_n^c\), \(C_5 \vee K_2^c\), \(C_7 \vee K_n^c\), \(C_9 \vee K_2^c\), \(C_{11} \vee K_n^c\), \(C_{19} \vee K_n^c\). This partially answers the question of gracefulness of \(n\)-cones which is listed as an open problem in the survey article by J.A. Gallian.

E.E. Guerin1
1Department of Mathematics Seton Hall University South Orange, NJ 07079
Bruno Codenotti1, Ivan Gerace2, Giovanni Resta1
1Istituto di Informatica e Telematica del CNR, Area della Ricerca, Pisa (Italy).
2Universita degli Studi di Perugia, Perugia (Italy).
Abstract:

We tackle the problem of estimating the Shannon capacity of cycles of odd length. We present some strategies which allow us to find tight bounds on the Shannon capacity of cycles of various odd lengths, and suggest that the difficulty of obtaining a general result may be related to different behaviours of the capacity, depending on the “structure” of the odd integer representing the cycle length. We also describe the outcomes of some experiments, from which we derive the evidence that the Shannon capacity of odd cycles is extremely close to the value of the Lovasz theta function.

William D.Weakley1
1Department of Mathematical Sciences Indiana University – Purdue University Fort Wayne, IN 46805
Abstract:

The queen’s graph \(Q_n\) has the squares of the \(n \times n\) chessboard as its vertices; two squares are adjacent if they are in the same row, column, or diagonal. Let \(\gamma(Q_n)\) be the minimum size of a dominating set of \(Q_n\). Spencer proved that \(\gamma(Q_n) \geq {(n-1)}/{2}\) for all \(n\), and the author showed \(\gamma(Q_n) = {(n-1)}/{2}\) implies \(n \equiv 3 \pmod{4}\) and any minimum dominating set of \(Q_n\) is independent.

Define a sequence by \(n_1 = 3\), \(n_2 = 11\), and for \(i > 2\), \(n_i = 4n_{i-1} – n_{i-2} – 2\). We show that if \(\gamma(Q_n) = {(n-1)}/{2}\) then \(n\) is a member of the sequence other than \(n_3 = 39\), and (counting from the center) the rows and columns occupied by any minimum dominating set of \(Q_n\) are exactly the even-numbered ones. This improvement in the lower bound enables us to find the exact value of \(\gamma(Q_n)\) for several \(n\); \(\gamma(Q_n) = {(n+1)}/{2}\) is shown here for \(n = 23, 39\), and elsewhere for \(n = 27, 71, 91, 115, 131\).

Subhamoy Maitra1, Palash Sarkar2
1 Computer and Statistical Service Centre Indian Statistical Institute 203, B.T. Road, Calcutta 700 035, INDIA
2Department of Combinatorics and Optimization University of Waterloo 200 University Avenue West Waterloo, Ontario Canada N2L 3G1
Abstract:

A characterization of symmetric bent functions has been presented in [3]. Here, we provide a simple proof of the same result.

E. J.Cockayne1, O. Favaront2, C.M. Mynhardt3
1Department of Mathematics, University of Victoria, P. O. Box 3045, Victoria, BC, CANADA V8W 3P4;
2LRI, Bat. 490, Université Paris-Sud, 91405 Orsay Cedex, FRANCE;
3Department of Mathematics, University of South Africa, P. O. Box 392, Unisa, 0003 SOUTH AFRICA;
Abstract:

We prove that the total domination number of an \(n\)-vertex claw-free cubic graph is at most \({n}/{2}\).

Martin Baca1, Mirka Miller2
1 Department of Applied Mathematics Technical University, Ko8ice, Slovak Republic
2Department of Computer Science and Software Engineering The University of Newcastle, Australia
Abstract:

This paper deals with the problem of labeling the edges of a plane graph in such a way that the weight of a face is the sum of the labels of the edges surrounding that face. The paper describes \((a, d)\)-face antimagic labeling of a certain class of convex polytopes.

Abstract:

Below, we prove that there are exactly 244 nonisomorphic cyclic decompositions of the complete graph \(K_{25}\) into cubes. The full list of such decompositions is given in the Appendix.

J. Cormie1, V. Lineki1, Sheng Jiang2, Rui-Chen Chen2
1 Department of Mathematics and Statistics University of Winnipeg Winnipeg, Manitoba, R3B 2E9 CANADA
2Department of Mathematics Yangzhou University Yangzhou, Jiangsu 225002 P. R. CHINA
Abstract:

The magic square is probably the most popular and well-studied topic in recreational mathematics. We investigate a variation on this classic puzzle — the antimagic square. We review the history of the problem, and the structure of the design. We then present computational results on the enumeration and construction. Finally, we describe a construction for all orders.

Bader F.AlBdaiwi1, Peter Horak1
1 Department of Mathematics and Computer Science Kuwait University Kuwait
Abstract:

We establish a necessary and sufficient condition for the existence of a perfect distance-\(d\) placement in 3-dimensional tori, for both regular and irregular cases.

Special Issues

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