
Alejandro Estrada-MorenoUniversidad Rovira i Virgili | URV · Department of Computer Engineering and Mathematics (DEIM)
Alejandro Estrada-Moreno
Ph.D. in Computer Engineering and Mathematics
About
58
Publications
11,923
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
710
Citations
Introduction
Additional affiliations
April 2016 - April 2016
November 2012 - present
Publications
Publications (58)
We extend a warm invitation to submit original research papers or reviews for this Special Issue on "Symmetry and Graph Theory", focusing on recent developments in graph theoretical research, particularly in relation to symmetry. Graph theory has widespread applications across various research domains, making this Issue a platform for valuable cont...
The aim of this Special Issue is to attract leading researchers in different areas of discrete mathematics and theoretical computer science. To this end, it is intended to involve in this Special Issue new high-quality results on discrete mathematics including (but not limited to) graph theory, coding theory, cryptography, algorithms and complexity...
Given a connected graph G=(V(G),E(G)), a set S⊆V(G) is said to be a k-metric generator for G if any pair of different vertices in V(G) is distinguished by at least k elements of S. A metric generator of minimum cardinality among all k-metric generators is called a k-metric basis and its cardinality is the k-metric dimension of G. We initially prese...
This paper is devoted to the study of the quasi-total strong differential of a graph, and it is a contribution to the Special Issue “Theoretical computer science and discrete mathematics” of Symmetry. Given a vertex x∈V(G) of a graph G, the neighbourhood of x is denoted by N(x). The neighbourhood of a set X⊆V(G) is defined to be N(X)=⋃x∈XN(x), whil...
Let \(w=(w_0,w_1, \dots ,w_l)\) be a vector of nonnegative integers such that \( w_0\ge 1\). Let G be a graph and N(v) the open neighbourhood of \(v\in V(G)\). We say that a function \(f: V(G)\longrightarrow \{0,1,\dots ,l\}\) is a w-dominating function if \(f(N(v))=\sum _{u\in N(v)}f(u)\ge w_i\) for every vertex v with \(f(v)=i\). The weight of f...
Let $w=(w_0,w_1, \dots,w_l)$ be a vector of nonnegative integers such that $ w_0\ge 1$. Let $G$ be a graph and $N(v)$ the open neighbourhood of $v\in V(G)$. We say that a function $f: V(G)\longrightarrow \{0,1,\dots ,l\}$ is a $w$-dominating function if $f(N(v))=\sum_{u\in N(v)}f(u)\ge w_i$ for every vertex $v$ with $f(v)=i$. The weight of $f$ is d...
This paper introduces a general approach to the idea of protection of graphs, which encompasses the known variants of secure domination and introduces new ones. Specifically, we introduce the study of secure w-domination in graphs, where w=(w0,w1,…,wl) is a vector of nonnegative integers such that w0≥1. The secure w-domination number is defined as...
In this paper, we show that the Italian domination number of every lexicographic product graph $G\circ H$ can be expressed in terms of five different domination parameters of $G$. These parameters can be defined under the following unified approach, which encompasses the definition of several well-known domination parameters and introduces new ones...
In the classical team orienteering problem (TOP), a fixed fleet of vehicles is employed, each of them with a limited driving range. The manager has to decide about the subset of customers to visit, as well as the visiting order (routes). Each customer offers a different reward, which is gathered the first time that it is visited. The goal is then t...
Natural catastrophes with their widespread damage can overwhelm the financial systems of large communities. Catastrophe insurance is a well-understood financial risk transfer mechanism, aiming to provide resilience in the face of adversity. However, catastrophe insurance has generally a low penetration, mainly due to its high cost or to distrust of...
Let $(X,d)$ be a metric space. A set $S\subseteq X$ is said to be a $k$-metric generator for $X$ if and only if for any pair of different points $u,v\in X$, there exist at least $k$ points $w_1,w_2, \ldots w_k\in S$ such that $d(u,w_i)\ne d(v,w_i),\; \textrm{for all}\; i\in \{1, \ldots k\}.$ Let $\mathcal{R}_k(X)$ be the set of metric generators fo...
In this article, we obtain general bounds and closed formulas for the secure total domination number of rooted product graphs. The results are expressed in terms of parameters of the factor graphs involved in the rooted product.
In the context of a supply chain for the animal‐feed industry, this paper focuses on optimizing replenishment strategies for silos in multiple farms. Assuming that a supply chain is essentially a value chain, our work aims at narrowing this chasm and putting analytics into practice by identifying and quantifying improvements on specific stages of a...
The concepts of unmanned aerial vehicles and self-driving vehicles are gaining relevance inside the smart city environment. This type of vehicles might use ultra-reliable telecommunication systems, Internet-based technologies, and navigation satellite services to decide about the routes they must follow to efficiently accomplish their mission and r...
This paper analyzes the single-source capacitated facility location problem (SSCFLP) with soft capacity constraints. Hence, the maximum capacity at each facility can be potentially exceed by incurring in a penalty cost, which increases with the constraint-violation gap. In some realistic scenarios, this penalty cost can be modelled as a piecewise f...
In supermarkets, perishable products need to be sold to consumers before a given deadline, after which their monetary value is significantly diminished or even completely lost. In the case of valuable products that should not be wasted, the following operational decision needs to be made as this deadline approaches: which is the best way to realloc...
The multiperiod vehicle routing problem (MPVRP) is an extension of the vehicle routing problem in which customer demands have to be delivered in one of several consecutive time periods, for example, the days of a week. We introduce and explore a variant of the MPVRP in which the carrier offers a price discount in exchange for delivery flexibility....
In this zip file are the Multi-Depot VRP described in Cordeau and Pisinger (instance p01 to p23 and pr01 to pr10, respectively) adapted to Multi-Period VRP ones. In this modification each depot is geographically co-located. Specifically, we replace the localizations of depots in each MDVRP instance by a single depot located at the geometric center...
This is the souce code corresponding to the article "A Biased-Randomized Algorithm for Redistribution of Perishable Food Inventories in Supermarket Chains"
Content of three instances tested with the ECAM and BRILS algorithms. The solutions given by each of these two algorithms are also shown.
Impact of varying deadlines on total costs for instance p01 and pr01.
As a generalization of the concept of the partition dimension of a graph, this article introduces the notion of the k-partition dimension. Given a nontrivial connected graph G=(V,E), a partition Π of V is said to be a k-partition generator of G if any pair of different vertices u,v∈V is distinguished by at least k vertex sets of Π i.e., there exist...
As a generalization of the concept of the partition dimension of a graph, this article introduces the notion of the $k$-partition dimension. Given a nontrivial connected graph $G=(V,E)$, a partition $\Pi$ of $V$ is said to be a $k$-partition generator for $G$ if any pair of different vertices $u,v\in V$ is distinguished by at least $k$ vertex sets...
In this paper we propose formulas for the distance between vertices of a generalized Sierpi?ski graph S(G, t) in terms of the distance between vertices of the base graph G. In particular, we deduce a recursive formula for the distance between an arbitrary vertex and an extreme vertex of S(G, t), and we obtain a recursive formula for the distance be...
In a graph G = (V, E), a vertex v ε V is said to distinguish two vertices x and y if dG(v, x) ≠ dG(v, y). A set S ⊆ V is said to be a local metric generator for G if any pair of adjacent vertices of G is distinguished by some element of S. A minimum local metric generator is called a local metric basis and its cardinality the local metric dimension...
Given a connected graph a set S ⊆ V is a k-metric generator for G if for any two different vertices u, v ∈ V, there exist at least k vertices such that dG(u, wi) ≠ dG(v, wi) for every . A metric generator of minimum cardinality is called a k-metric basis and its cardinality the k-metric dimension of G. We make a study concerning the complexity of s...
Given a connected simple graph G=(V(G),E(G))G=(V(G),E(G)) , a set S⊆V(G)S⊆V(G) is said to be a 2-metric generator for G if and only if for any pair of different vertices u,v∈V(G)u,v∈V(G) , there exist at least two vertices w1,w2∈Sw1,w2∈S such that dG(u,wi)≠dG(v,wi)dG(u,wi)≠dG(v,wi) , for every i∈{1,2}i∈{1,2} , where dG(x,y)dG(x,y) is the length of...
In this paper we propose formulas for the distance between vertices of a generalized Sierpi´nskiSierpi´nski graph S(G, t) in terms of the distance between vertices of the base graph G. In particular, we deduce a recursive formula for the distance between an arbitrary vertex and an extreme vertex of S(G, t), and we obtain a recursive formula for the...
Let ${\mathcal G}$ be a graph family defined on a common (labeled) vertex set
$V$. A set $S\subseteq V$ is said to be a simultaneous metric generator for
${\cal G}$ if for every $G\in {\cal G}$ and every pair of different vertices
$u,v\in V$ there exists $s\in S$ such that $d_{G}(s,u)\ne d_{G}(s,v)$, where
$d_{G}$ denotes the geodesic distance. A s...
Let ${\cal G}$ be a graph family defined on a common vertex set $V$ and let
$d$ be a distance defined on every graph $G\in {\cal G}$. A set $S\subset V$ is
said to be a simultaneous metric generator for ${\cal G}$ if for every $G\in
{\cal G}$ and every pair of different vertices $u,v\in V$ there exists $s\in S$
such that $d(s,u)\ne d(s,v)$. The sim...
In this paper we propose formulas for the distance between vertices of a generalized Sierpi\'{n}ski graph $S(G,t)$ in terms of the distance between vertices of the base graph $G$. In particular, we deduce a recursive formula for the distance between an arbitrary vertex and an extreme vertex of $S(G,t)$, and we obtain a recursive formula for the dis...
Given a simple and connected graph G=(V,E), and a positive integer k, a set S⊆V is said to be a k-metric generator for G, if for any pair of different vertices u,v∈V, there exist at least k vertices w1,w2,...,wk∈S such that dG(u,wi)≠dG(v,wi), for every i∈{1,...,k}, where dG(x,y) denotes the distance between x and y. The minimum cardinality of a k-m...
Let $(X,d)$ be a metric space. A set $S\subseteq X$ is said to be a $k$-metric generator for $X$ if and only if for any pair of different points $u,v\in X$, there exist at least $k$ points $w_1,w_2, \ldots w_k\in S$ such that $d(u,w_i)\ne d(v,w_i),\; \mbox{\rm for all}\; i\in \{1, \ldots k\}.$ Let $\mathcal{R}_k(X)$ be the set of metric generators...
http://www.tdx.cat/bitstream/handle/10803/378343/TESI.pdf
The metric dimension is quite a well-studied graph parameter. Recently, the adjacency dimension and the local metric dimension have been introduced and studied. In this paper, we give a general formula for the local metric dimension of the lexicographic product $G \circ \mathcal{H}$ of a connected graph $G$ of order $n$ and a family $\mathcal{H}$ c...
The metric dimension is quite a well-studied graph parameter. Recently, the adjacency dimension and the local metric dimension have been introduced and studied. In this paper, we give a general formula for the local metric dimension of the lexicographic product $G \circ \mathcal{H}$ of a connected graph $G$ of order $n$ and a family $\mathcal{H}$ c...
Let \(\mathcal{G}\) be a family of graphs defined on a common (labelled) vertex set V. A set \(S\subset V\) is said to be a simultaneous strong metric generator for \(\mathcal{G}\) if it is a strong metric generator for every graph of the family. The minimum cardinality among all simultaneous strong metric generators for \(\mathcal{G}\), denoted by...
The General Randi\'c index $R_\alpha$ of a simple graph $G$ is defined as \[
R_\alpha(G)=\sum_{v_{i}\sim v_{j}} (\delta_{i}\delta_{j})^\alpha, \] where
$\delta_i$ denotes the degree of the vertex $v_i$. Rodr\'iguez-Vel\'azquez and
Tom\'as-Andreu [MATCH Commun. Math. Comput. Chem. 74 (1) (2015) 145--160]
obtained closed formulae for the Randi\'c ind...
In this paper we obtain closed formulae for several parameters of generalized
Sierpi\'{n}ski graphs $S(G,t)$ in terms of parameters of the base graph $G$. In
particular, we focus on the chromatic, vertex cover, clique and domination
numbers.
In this article we study the problem of finding the $k$-adjacency dimension of a graph. We give some necessary and sufficient conditions
for the existence of a $k$-adjacency basis of an arbitrary graph $G$ and we obtain general results on
the $k$-adjacency dimension, including general bounds
and closed formulae for some families of graphs.
Several authors consider that the emergence of the Internet in election campaigns has changed the strategies of the political parties to present their government proposals, due to the potential use of these media to debate or interact among politicians and citizens. Others see the web as a new showcase for political programs. In this context, we ai...
A set S of vertices of a graph G is said to be a k -metric generator for G if for any u,v∈V(G)u,v∈V(G), u≠vu≠v, there exists Suv⊆SSuv⊆S such that |Suv|≥k|Suv|≥k and for every w∈Suvw∈Suv, dG(u,w)≠dG(v,w)dG(u,w)≠dG(v,w). A metric generator of minimum cardinality is called a k-metric basis and its cardinality the k-metric dimension of G. We give a nec...
A vertex v ∈ V (G) is said to distinguish two vertices x, y ∈ V (G) of a graph G if the distance from v to x is different from the distance from v to y. A set W ⊆ V (G) is a total resolving set for a graph G if for every pair of vertices x, y ∈ V (G), there exists some vertex w ∈ W − {x, y} which distinguishes x and y, while W is a weak total resol...
Given a connected simple graph $G=(V,E)$, and a positive integer $k$, a set $S\subseteq V$ is said to be a $k$-metric generator for $G$ if and only if for any pair of different vertices $u,v\in V$, there exist at least $k$ vertices $w_1,w_2,...,w_k\in S$ such that $d_G(u,w_i)\ne d_G(v,w_i)$, for every $i\in \{1,...,k\}$, where $d_G(x,y)$ is the len...
Given a connected graph $G=(V,E)$, a set $S\subseteq V$ is said to be a
$k$-metric generator for $G$ if the elements of any pair of vertices of $G$ are
distinguished by at least $k$ elements of $S$, {\em i.e.}, for any two
different vertices $u,v\in V$, there exist at least $k$ vertices
$w_1,w_2,...,w_k\in S$ such that $d_G(u,w_i)\ne d_G(v,w_i)$ fo...
As a generalization of the concept of metric basis, this article introduces
the notion of $k$-metric basis in graphs. Given a connected graph $G=(V,E)$, a
set $S\subseteq V$ is said to be a $k$-metric generator for $G$ if the elements
of any pair of vertices of $G$ are distinguished by at least $k$ elements of
$S$, {\em i.e.}, for any two different...
Se describe una nueva metodología para la vigilancia agrometeorológica de las condiciones de explotación del ganado vacuno, mediante la integración de salidas de modelos globales de pronóstico del clima y los datos de las estaciones meteorológicas de superficie ajustados a las características del archipiélago cubano. Como criterios para la evaluaci...
It is proposed a surveillance system to detect the risk of occurrence of forest fires on the basis of information from meteorological stations, due mainly to lack of operational daily departures to assess the conditions of risk of fires nationwide. Rates were used Nesterov amended and Monte Alegre, which were estimated from data from the 68 meteoro...
It is proposed a surveillance system to detect the risk of occurrence of forest fires on the basis of information from meteorological stations, due mainly to lack of operational daily departures to assess the conditions of risk of fires nationwide. Rates were used Nesterov amended and Monte Alegre, which were estimated from data from the 68 meteoro...
The current Cuban model for biometeorological forecasts are based upon the design and preliminary application of the Health Watch and Warning System obtained by Lecha and Delgado (1996) and the new version developed by Estrada, Moya and Lecha (2006). The software made possible to calculate the differences in 24 hours of the partial oxygen density i...
There has been a rise of medical service provision in Cuba and the country shows health indicators comparable to those of the most developed nations. A new procedure that will be useful for continuos improvement of the Cuban population´s health is being worked out. It refers to the biometeorological forecast method aimed at providing health institu...
Los pronósticos biometeorológicos elaborados a partir de los resultados del modelo "PronBiomet" se comenzaron a difundir al público en el año 2008 mediante una plataforma web hospedada en el Portal de la Ciencia de la provincia de Villa Clara, Cuba. Inicialmente los pronóisticos se hicieron solamente para Cuba, después de agregó la región de Nortea...