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-1405
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 14, 2019
- Pages: 1-6 (Paper #5)
- Published: 31/12/2019
In this paper, we present a method to construct a cyclic orthogonal double cover (CODC) of circulant graphs by certain kinds of coronas that model by linear functions.
- Research article
- https://doi.org/10.61091/ojac-1404
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 14, 2019
- Pages: 1-22 (Paper #4)
- Published: 31/12/2019
Following the work of Cano and Díaz, we study continuous binomial coefficients and Catalan numbers. We explore their analytic properties, including integral identities and generalizations of discrete convolutions. We also conduct an in-depth analysis of a continuous analogue of the binomial distribution, including a stochastic representation as a Goldstein-Kac process.
- Research article
- https://doi.org/10.61091/ojac-1403
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 14, 2019
- Pages: 1-13 (Paper #3)
- Published: 31/12/2019
In this paper, we introduce a new operator in order to derive some properties of homogeneous symmetric functions. By making use of the proposed operator, we give some new generating functions for \( k \)-Fibonacci numbers, \( k \)-Pell numbers, and the product of sequences and Chebyshev polynomials of the second kind.
- Research article
- https://doi.org/10.61091/ojac-1402
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 14, 2019
- Pages: 1-13 (Paper #2)
- Published: 31/12/2019
In this paper, we introduce the concept block matrix (B-matrix) of a graph \( G \), and obtain some coefficients of the characteristic polynomial \( \phi(G, \mu) \) of the B-matrix of \( G \). The block energy \( E_B(G) \) is established. Further upper and lower bounds for \( E_B(G) \) are obtained. In addition, we define a uni-block graph. Some properties and new bounds for the block energy of the uni-block graph are presented.
- Research article
- https://doi.org/10.61091/ojac-1401
- Full Text
- Online Journal of Analytic Combinatorics
- Issue 14, 2019
- Pages: 1-7 (Paper #1)
We consider analogs of several classical diophantine equations, such as Fermat’s last theorem and Catalan’s conjecture, for certain classes of analytic functions. We give simple direct proofs avoiding use of deep theorems in complex analysis. As a byproduct of our results, we obtain new proofs for the corresponding results over polynomials.
- Research article
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 111
- Pages: 305-315
- Published: 30/12/2019
We define the \( (i, j) \)-liars’ domination number of \( G \), denoted by \( LR(i, j)(G) \), to be the minimum cardinality of a set \( L \subseteq V(G) \) such that detection devices placed at the vertices in \( L \) can precisely determine the set of intruder locations when there are between 1 and \( i \) intruders and at most \( j \) detection devices that might “lie”.
We also define the \( X(c_1, c_2, \ldots, c_t, \ldots) \)-domination number, denoted by \( \gamma _{X(c_1, c_2, \ldots, c_t, \ldots)}(G) \), to be the minimum cardinality of a set \( D \subseteq V(G) \) such that, if \( S \subseteq V(G) \) with \( |S| = k \), then \( |(\bigcup_{v \in S} N[v]) \cap D| \geq c_k \). Thus, \( D \) dominates each set of \( k \) vertices at least \( c_k \) times making \( \gamma_{X(c_1, c_2, \ldots, c_t, \ldots)}(G) \) a set-sized dominating parameter. We consider the relations between these set-sized dominating parameters and the liars’ dominating parameters.
- Research article
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 111
- Pages: 295-304
- Published: 30/12/2019
For Cauchy numbers of the first kind \( \{a_n\}{n \geq 0} \) and Cauchy numbers of the second kind \( \{b_n\}{n \geq 0} \), this paper focuses on the log-convexity of some sequences related to \( \{a_n\}{n \geq 0} \) and \( \{b_n\}{n \geq 0} \). For example, we discuss log-convexity of \( \{n|a_n| – |a_{n+1}|\}{n \geq 1} \), \( \{b{n+1} – nb_n\}{n \geq 1} \), \( \{n|a_n|\}{n \geq 1} \), and \( \{(n + 1)b_n\}_{n \geq 0} \). In addition, we investigate log-balancedness of some sequences involving \( a_n \) (or \( b_n \)).
- Research article
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 111
- Pages: 283-294
- Published: 30/12/2019
Let \( G \) be a graph. We define the distance \( d \) pebbling number of \( G \) to be the smallest number \( s \) such that if \( s \) pebbles are placed on the vertices of \( G \), then there must exist a sequence of pebbling moves which takes a pebble to a vertex which is at a distance of at least \( d \) from its starting point. In this article, we evaluate the distance \( d \) pebbling numbers for a directed cycle graph with \( n \) vertices.
- Research article
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 111
- Pages: 279-282
- Published: 30/12/2019
Let \( G \) be a \( k \)-connected (\( k \geq 2 \)) graph of order \( n \). If \( \gamma(G^c) \geq n – k \), then \( G \) is Hamiltonian or \( K_k \vee K_{k+1}^c \), where \( \gamma(G^c) \) is the domination number of the complement of the graph \( G \).
- Research article
- Full Text
- Journal of Combinatorial Mathematics and Combinatorial Computing
- Volume 111
- Pages: 269-278
- Published: 30/12/2019
An \emph{Italian dominating function} on a digraph \( D \) with vertex set \( V(D) \) is defined as a function \( f : V(D) \to \{0, 1, 2\} \) such that every vertex \( v \in V(D) \) with \( f(v) = 0 \) has at least two in-neighbors assigned 1 under \( f \) or one in-neighbor \( w \) with \( f(w) = 2 \). The weight of an Italian dominating function is the sum \( \sum_{v \in V(D)} f(v) \), and the minimum weight of an Italian dominating function \( f \) is the \emph{Italian domination number}, denoted by \( \gamma_I(D) \). We initiate the study of the Italian domination number for digraphs, and we present different sharp bounds on \( \gamma_I(D) \). In addition, we determine the Italian domination number of some classes of digraphs. As applications of the bounds and properties on the Italian domination number in digraphs, we give some new and some known results of the Italian domination number in graphs.




