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.

Istvan Mező1, José Ramírez2
1Department of Mathematics, Nanjing University of Information Science and Technology, Nanjing 210044, P. R. CHINA.
2Departamento de Matemáticas, Universidad Nacional de Colombia, Bogotá, COLOMBIA
Abstract:

In this paper, we define the q-analogue of the so-called symmetric infinite matrix algorithm. We find an explicit formula for entries in the associated matrix and also for the generating function of the k-th row of this matrix for each fixed k. This helps us to derive analytic and number theoretic identities with respect to the q-harmonic numbers and q-hyperharmonic numbers of Mansour and Shattuck.

Aubrey Blecher1, Charlotte Brennan1, Arnold Knopfmacher 1
1The John Knopfmacher Centre for Applicable Analysis and Number Theory, School of Mathematics, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
Abstract:

Bargraphs are lattice paths in \(\mathbb{N}_0^2\) with three allowed types of steps: up \((0,1)\), down \((0,-1)\), and horizontal \((1,0)\). They start at the origin with an up step and terminate immediately upon return to the \(x\)-axis. A wall of size \(r\) is a maximal sequence of \(r\) adjacent up steps. In this paper, we develop the generating function for the total number of walls of fixed size \(r \geq 1\). We then derive asymptotic estimates for the mean number of such walls.

Sean Prendiville1
1School of Mathematics, University of Manchester, Manchester, UK
Abstract:

We survey four instances of the Fourier analytic ‘transference principle’or ‘dense model lemma’, which allows one to approximate an unbounded function on the integers by a bounded function with similar Fourier transform. Such a result forms a component of a general method pioneered by Green to count solutions to a single linear equation in a sparse subset of integers.

Giorgis Petridis1
1Department of Mathematics, University of Georgia, Athens, GA 30602, USA
Abstract:

Let \( E \subseteq \mathbb{F}_q^2 \) be a set in the 2-dimensional vector space over a finite field with \( q \) elements, which satisfies \(|E| > q\). There exist \( x, y \in E \) such that \(|E \cdot (y – x)| > q/2\). In particular, \( (E + E) \cdot (E – E) = \mathbb{F}_q.\)

Abstract:

Let \((x(n))_{n \geq 1}\) be an \(s\)-dimensional Niederreiter-Xing sequence in base \(b\). Let \(D((x(n))_{n=1}^N)\) be the discrepancy of the sequence \((x(n))_{n=1}^N\). It is known that \(ND((x(n))_{n=1}^N) = O(\ln^s N)\) as \(N \to \infty\). In this paper, we prove that this estimate is exact. Namely, there exists a constant \(K > 0\), such that
\[
\inf_{w \in [0,1]^s} \sup_{1 \leq N \leq b^m} ND((x(n) \oplus w)_{n=1}^N) \geq K \ln^s \quad \text{ for } m = 1, 2, \ldots.
\]

We also get similar results for other explicit constructions of \((t,s)\)-sequences.

Maxie D. Schmidt1
1School of Mathematics, Georgia Institute of Technology, Atlanta, GA 30332
Abstract:

We define a new class of generating function transformations related to polylogarithm functions, Dirichlet series, and Euler sums. These transformations are given by an infinite sum over the jth derivatives of a sequence generating function and sets of generalized coefficients satisfying a non-triangular recurrence relation in two variables. The generalized transformation coefficients share a number of analogous properties with the Stirling numbers of the second kind and the known harmonic number expansions of the unsigned Stirling numbers of the first kind.

We prove a number of properties of the generalized coefficients which lead to new recurrence relations and summation identities for the k-order harmonic number sequences. Other  applications of the generating function transformations we define in the article include new series expansions for the polylogarithm function, the alternating zeta function, and the Fourier series for the periodic Bernoulli polynomials. We conclude the article with a discussion of several specific new “almost” linear recurrence relations between the integer-order harmonic numbers and the generalized transformation coefficients, which provide new applications to studying the limiting behavior of the zeta function constants, ζ(k), at integers k ≥ 2.

Ali Boussayoud1
1LMAM Laboratory and Department of Mathematics, Mohamed Seddik Ben Yahia University, Jijel, Algeria.
Abstract:

Generating functions for Pell and Pell-Lucas numbers are obtained. Applications are given for some results recently obtained by Mansour [Mansour12]; by using an alternative approach that considers the action of the operator \(\delta_{e_1 e_2}^k\) to the series \(\sum_{j=0}^\infty a_j (e_1 z)^j\).

Katherine F. Benson1
1501 Westminster Ave, Westminster College, Fulton, MO 65251
Abstract:

A radio labeling of a simple connected graph \( G \) is a function \( f: V(G) \to \mathbb{Z}^+ \) such that for every two distinct vertices \( u \) and \( v \) of \( G \),
$$distance(u, v) + |f(u) – f(v)| \geq 1 + diameter(G).$$
The radio number of a graph \( G \) is the smallest integer \( M \) for which there exists a labeling \( f \) with \( f(v) \leq M \) for all \( v \in V(G) \). An edge-balanced caterpillar graph is a caterpillar graph that has an edge such that removing this edge results in two components with an equal number of vertices. In this paper, we determine the radio number of particular edge-balanced caterpillars as well as improve the lower bounds of the radio number of other edge-balanced caterpillars.

Ryan C. Bunge1, Saad I. El-Zanati1, Jessica Klister2, Dan Roberts3, Catherine Ruddell4
1Illinois State University Normal, Illinois, U.S.A.
2University of Wisconsin-La Crosse La Crosse, Wisconsin, U.S.A.
3Illinois Wesleyan University Bloomington, illinois, U.S.A.
4 Eastern Illinois University Bloomington Charleston, Illinois, U.S.A.
Abstract:

It is known that an ordered \(\rho\)-labeling of a bipartite graph \( G \) with \( n \) edges yields a cyclic \( G \)-decomposition of \( K_{2nx+1} \) for every positive integer \( x \). We extend the concept of an ordered \(\rho\)-labeling to bipartite digraphs and show that an ordered directed \(\rho\)-labeling of a bipartite digraph \( D \) with \( n \) arcs yields a cyclic \( D \)-decomposition of \( K_{nx+1}^* \) for every positive integer \( x \). We also find several classes of bipartite digraphs that admit an ordered directed \(\rho\)-labeling.

Xuemei Liu1, Yingmo Jie1, Yinbo Zhang2
1(College of Science, Civil Aviation University of China, Tianjin, 300300, P.R.China)
2(Department of Aeronautical Mechanics Engineering, Civil Aviation University of China, Tianjin, 900300, P.R.China)
Abstract:

Compressed sensing (CS), which is a rising technique of signal processing, successfully manages the huge expenditure of increasing the sampling rate as well as the intricate issues to our work. Hence, more and more attention has been paid to CS during recent years. In this paper, we construct a family of error-correcting pooling designs based on singular linear space over finite fields, which can be efficiently applied to signal processing in terms of CS.

Special Issues

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