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.
- Research article
- https://doi.org/10.61091/ojac-1507
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 15, 2020
- Pages: 1-34 (Paper #7)
- Published: 31/12/2020
Binomial coefficients of the form \( \binom{\alpha}{\beta} \) for complex numbers \( \alpha \) and \( \beta \) can be defined in terms of the gamma function, or equivalently the generalized factorial function. Less well-known is the fact that if \( n \) is a natural number, the binomial coefficient \( \binom{n}{x} \) can be defined in terms of elementary functions. This enables us to investigate the function \( \binom{n}{x} \) of the real variable \( x \). The results are completely in line with what one would expect after glancing at the graph of \( \binom{3}{x} \), for example, but the techniques involved in the investigation are not the standard methods of calculus. The analysis is complicated by the existence of removable singularities at all of the integer points in the interval \( [0, n] \), and requires multiplying, rearranging, and differentiating infinite series.
- Research article
- https://doi.org/10.61091/ojac-1506
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 15, 2020
- Pages: 1-42 (Paper #6)
- Published: 31/12/2020
In this paper, we analyze the stochastic properties of some large size (area) polyominoes’ perimeter such that the directed column-convex polyomino, the columnconvex polyomino, the directed diagonally-convex polyomino, the staircase (or parallelogram) polyomino, the escalier polyomino, the wall (orbargraph) polyomino. All polyominoes considered here are made of contiguous, not-empty columns, without holes, such that each column must be adjacent to some cell of the previous column. We compute the asymptotic (for large size n) Gaussian distribution of the perimeter, including the corresponding Markov property of the chain of columns, and the convergence to classical Brownian motions of the perimeter seen as a trajectory according to the successive columns. All polyominoes of size n are considered as equiprobable.
- Research article
- https://doi.org/10.61091/ojac-1505
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 15, 2020
- Pages: 1-10 (Paper #5)
- Published: 31/12/2020
Convolution conditions are discussed for the \(q\)-analogue classes of Janowski starlike, convex and spirallike functions.
- Research article
- https://doi.org/10.61091/ojac-1504
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 15, 2020
- Pages: 1-27 (Paper #4)
- Published: 31/12/2020
we discuss a framework for constructing large subsets of \(\mathbb{R}^n\) and \(K^n\) for non-archimedean local fields \(K\). This framework is applied to obtain new estimates for the Hausdorff dimension of angle-avoiding sets and to provide a counterexample to a limiting version of the Capset problem.
- Research article
- https://doi.org/10.61091/ojac-1503
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 15, 2020
- Pages: 1-10 (Paper #3)
- Published: 31/12/2020
Let \( R \) be a commutative ring with unity and \( M \) be an \( R \)-module. The total graph of \( M \) with respect to the singular submodule \( Z(M) \) of \( M \) is an undirected graph \( T(\Gamma(M)) \) with vertex set as \( M \) and any two distinct vertices \( x \) and \( y \) are adjacent if and only if \( x + y \in Z(M) \). In this paper, the author attempts to study the domination in the graph \( T(\Gamma(M)) \) and investigate the domination number and the bondage number of \( T(\Gamma(M)) \) and its induced subgraphs. Some domination parameters of \( T(\Gamma(M)) \) are also studied. It has been shown that \( T(\Gamma(M)) \) is excellent, domatically full, and well covered under certain conditions.
- Research article
- https://doi.org/10.61091/ojac-1502
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 15, 2020
- Pages: 1-18 (Paper #2)
- Published: 31/12/2020
In this paper, we study a class of sequences of polynomials linked to the sequence of Bell polynomials. Some sequences of this class have applications on the theory of hyperbolic differential equations and other sequences generalize Laguerre polynomials and associated Lah polynomials. We discuss, for these polynomials, their explicit expressions, relations to the successive derivatives of a given function, real zeros and recurrence relations. Some known results are significantly simplified.
- Research article
- https://doi.org/10.61091/ojac-1501
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 15, 2020
- Pages: 1-10 (Paper #1)
- Published: 31/12/2020
We show that if \( G \) is a discrete Abelian group and \( A \subseteq G \) has \( \|1_A\|_{B(G)} \leq M \), then \( A \) is \( O(\exp(\pi M)) \)-stable in the sense of Terry and Wolf.
- Research article
- Full Text
- Congressus Numerantium
- Volume 234
- Pages: 261-272
- Published: 31/12/2019
A Magic Venn Diagram is a magic figure where regions of a Venn diagram are labeled such that the sums of the regional labels of each set are the same. We have developed a backtracking search to count the number of Magic Venn Diagrams. The algorithm could determine the number of Magic Venn Diagrams for all Venn diagrams with four sets. This paper presents the algorithm with its applied heuristics and lists the computational results.
- Research article
- Full Text
- Congressus Numerantium
- Volume 234
- Pages: 247-260
- Published: 31/12/2019
A famous open problem in the field of rendezvous search is to ascertain the rendezvous value of the symmetric rendezvous problem on the line, wherein both agents begin two units apart. We provide a new, Bayesian framework to both create new strategies for the agents to follow and to provide a new interpretation of previously posited strategies.
Additionally, we have developed a method that modifies any strategy, even those with potentially infinite expected meeting time, into a new strategy that is guaranteed to have a finite expected meeting time. This process, combined with using our Bayesian framework to create new strategies, yields an upper bound that is within one percent of the current best upper bound for the symmetric rendezvous value.
- Research article
- Full Text
- Congressus Numerantium
- Volume 234
- Pages: 225-246
- Published: 31/12/2019
The Astronaut Problem is an open problem in the field of rendezvous search. The premise is that two astronauts randomly land on a planet and want to find one another. Research explores what strategies accomplish this in the least expected time.
To investigate this problem, we create a discrete model which takes place on the edges of the Platonic solids. Some baseline assumptions of the model are:
- The agents can see all of the faces around them.
- The agents travel along the edges from vertex to vertex and cannot jump.
- The agents move at a rate of one edge length per unit time.
The 3-dimensional nature of our model makes it different from previous work. We explore multi-step strategies, which are strategies where both agents move randomly for one step, and then follow a pre-determined sequence.
For the cube and octahedron, we are able to prove optimality of the “Left Strategy,” in which the agents move in a random direction for the first step and then turn left. In an effort to find lower expected times, we explore mixed strategies. Mixed strategies incorporate an asymmetric case which, under certain conditions, can result in lower expected times.
Most of the calculations were done using first-step decompositions for Markov chains.




