Juan Julián Merelo Guervós

University of Granada | UGR · Department of Architecture and Computer Technology

The Republic of Venice was one of the longest-lived states in modern history, and its stability and survival have been studied through many different angles. One of the main research angles is to try and find pivotal moments in its history that explain its eventual demise. In this paper, through the rigorous statistical analysis of a dataset of mar...

Centrality measures are an essential tool in understanding complex networks, since they give researcher insights on the role the different nodes/actors play in them. Among them, eigenvector centrality is a principled approach to these measures, using a mathematical operation on the connection matrix. This connection matrix includes connections from...

Marriage networks, which represent the matrimonial connections between different families in a given historical and geographical milieu, rarely take into account one aspect of internal family dynamics, namely the existence of intra-family marriages. The inclusion of such marriages, represented in the graph by self-loops, is essential to compute mor...

The Republic of Venice was one of the longest-lived states in modern history, and its stability and survival has been studied through many different angles, and one of them is to try and find pivotal moments in its history that explain it, or its eventual demise. In this paper, through the rigorous statistical analysis of the dataset of marriages b...

Messaging platforms are applications, generally mediated by an app, desktop program or the web, mainly used for synchronous communication among users. As such, they have been widely adopted officially by higher education establishments, after little or no study of their impact and perception by the teachers. We think that the introduction of these...

Designing a controller is typically an iterative process during which engineers must assess the performance of a design through time-consuming simulations; this becomes even more burdensome when using a population-based metaheuristic that evaluates every member of the population. Distributed algorithms can mitigate this issue, but these come with t...

During most of the lifespan of the Venetian republic, doges (the name their presidents received) were elected for life. However, a long tenure was a rare event, which effectively resulted in term limits, as has already been reported by several authors. In this paper, we examine the length of these tenures and their evolution during the existence of...

During most of the lifespan of the Venetian republic, doges or presidents were elected for life. However, a long tenure was a rare event, which effectively resulted in term limits, as has already been deported by several authors. In this paper we examine these tenures and its evolution during the existence of the Venetian republic, trying to prove...

At the beginning of this year one of the authors read “A brave new world”, a novel by Aldous Huxley. This book describes a dystopia, which anticipates the development of world-scale breeding technology, and how this technology creates the optimal human race. Taking into account that when talking about genetic algorithms our goal is to achieve the o...

The Venetian republic was one of the most successful trans-modern states, surviving for a millennium through innovation, commercial cunning, exploitation of colonies and legal stability. Part of the success might be due to its government structure, a republic ruled by a doge chosen among a relatively limited set of Venetian patrician families. In t...

The use of new technologies such as messaging applications and chatbots in higher education is rapidly growing in Western countries. This entails a careful consideration of the potential opportunities and/or challenges of adopting these tools. Hence, a comprehensive examination of the teachers’ opinions and needs in this discipline can shed light o...

Following decades of sustained improvement, metaheuristics are one of the great success stories of optimization research. However, in order for research in metaheuristics to avoid fragmentation and a lack of reproducibility, there is a pressing need for stronger scientific and computational infrastructure to support the development, analysis and co...

Introducing new technologies such as messaging platforms, and the chatbots attached to them, in higher education, is rapidly growing. This introduction entails a careful consideration of the potential opportunities and/or challenges of adopting these tools. Hence, a thorough examination of the teachers' experiences in this discipline can shed light...

In this work, we propose, through the use of population-based metaheuristics, an optimization method that solves the problem of autonomous path tracking using a rear-wheel fuzzy logic controller. This approach enables the design of controllers using rules that are linguistically familiar to human users. Moreover, a new technique that uses three dif...

Using multiple-swarm PSO is a technique used in recent years to help improve the performance of nature-inspired optimization algorithms. A distributed PSO algorithm can work in every swarm in parallel and asynchronously communicate particles between them. However, the communication design is not a trivial task because any architectural change will...

Designing neural networks for classification or regression can be considered a search problem, and, as such, can be approached using different optimization procedures, all of them with several design challenges: The first and more important is to constrain the search space in such a way that proper solutions can be found in a reasonable amount of t...

Classification tasks often include, among the large number of features to be processed in the datasets, many irrelevant and redundant ones, which can even decrease the efficiency of classifiers. Feature Selection (FS) is the most common preprocessing technique utilized to overcome the drawbacks of the high dimensionality of datasets and often has t...

This paper tries to find the best condition to use chatbots (conversational agents) in higher-education studies after pilots carried out at the University of Granada (Spain). Our aim, along with the rest of partners in EDUBOTS -an Erasmus + European Project which counts with two pedagogical chatbots-, is to improve students’ engagement in class, as...

This paper presents a method for creating Forex market predictive models using multi-agent and fuzzy systems, which have the objective of simulating the interactions that provoke changes in the price. Agents in the system represent traders performing buy and sell orders in a market, and fuzzy systems are used to model the rules followed by traders...

The success of metaheuristic optimization methods has led to the development of a large variety of algorithm paradigms. However, no algorithm clearly dominates all its competitors on all problems. Instead, the underlying variety of landscapes of optimization problems calls for a variety of algorithms to solve them efficiently. It is thus of prior i...

Evolution is a powerful problem-solving technique, extensively used for designing racing car controllers, but with a series of challenges: an evaluation function that can separate the best controllers from the rest, and a series of operators that can explore different possibilities in the controller search space. Within the context of the TORCS rac...

Science has a data management problem, as well as a project management problem. While industry data science teams have embraced the agile mindset, and adopted or created all kind of tools to create reproducible workflows, academia-based science is still (mostly) mired in a mindset that's focused on a single final product (a paper), without focusing...

Researchers in nature-inspired optimization have recently proposed multi-population asynchronous algorithms that split the evolutionary process between different search paradigms working in collaboration. These algorithms execute the optimization strategy by reading streams of messages containing solution populations from message queues. After sear...

Creating a story is a challenging task due to the the complex relations between the parts that make it up, which is why many new stories are built on those cohesive elements or patterns, called tropes that have been shown to work in the past. A trope is a recurring storytelling device or pattern, or sometimes a meta-element, used by the authors to...

Selecting the proper distance measure is very challenging for most clustering algorithms. Some common distance measures include Manhattan (City-block), Euclidean, Minkowski, and Chebyshev. The so called Nearest Point with Indexing Ratio (NPIR) is a recent clustering algorithm, which tries to overcome the limitations of other algorithms by identifyi...

Following decades of sustained improvement, metaheuristics are one of the great success stories of optimization research. However, in order for research in metaheuristics to avoid fragmentation and a lack of reproducibility, there is a pressing need for stronger scientific and computational infrastructure to support the development, analysis and co...

As part of the EDUBOTS Erasmus+ project, this paper is a small survey on technologies related to use of chatbots in the classroom and the expected outcomes of the pilot experience.

Concurrency is a powerful abstraction that can be used to model and implement multi-deme evolutionary algorithms, opening up additional design questions such as what the different populations in various threads can do and how they interact with each other (via a combination of populations). One approach is synchrony: although threads can run asynch...

Cellular evolutionary algorithms (cEAs) are a particular type of EAs in which a communication structure is imposed to the population and mating restricted to topographically nearby individuals. In general, these algorithms have longer takeover times than panmictic EAs and previous investigations argue that they are more efficient in escaping local...

The security policy rules in companies are generally proposed by the Chief Security Officer (CSO), who must, for instance, select by hand which access events are allowed and which ones should be forbidden. In this work we propose a way to automatically obtain rules that generalise these single-event based rules using Genetic Programming (GP), which...

This paper addresses the issue of estimating the computational complexity of optimizing real-coded multimodal functions where the aim is to find all global optima. The proposed complexity method provides a partial answer to this question in the form of the estimated sample size needed to sample all basins of attraction of all global optima at least...

The moving target defense from cyberattacks consists in changing the profile or signature of certain services in an Internet node so that an attacker is not able to identify it uniquely, or find specific angles of attack for it. From an optimization point of view, generating profiles that change and, besides, optimize security is a combinatorial op...

The concept of channel, a computational mechanism used to convey state to different threads of process execution, is at the core of the design of multi-threaded concurrent algorithms. In the case of concurrent evolutionary algorithms, channels can be used to communicate messages between several threads performing different evolution tasks related t...

Parallel island-model co-evolutionary algorithms are well-known methods, suitable for dealing with large multi-objective optimization problems. This paper proposes a version of these algorithms where each island modifies a fragment of the chromosome that encodes a possible solution to the problem. The objective of this paper is to demonstrate that...

This paper investigates the performance and scalability of a new update strategy for the particle swarm optimization (PSO) algorithm. The strategy is inspired by the Bak-Sneppen model of co-evolution between interacting species, which is basically a network of fitness values (representing species) that change over time according to a simple rule: t...

Event Takeover Values (ETV) measure the impact of each individual in the population dynamics of evolutionary algorithms (EA). Previous studies argue that ETV distribution of panmictic EAs fit power laws with exponent between 2.2 and 2.5 and that this property is insensitive to fitness landscapes and design choices of the EAs. One exception is cellu...

This paper presents a Java framework to implement dis-tributed applications via Bluetooth. It provides a high-level Application Programming Interface (API) which simplifies the creation of applica-tions for Bluetooth devices in Java ME and Java SE platforms. This framework is based in a client-server architecture and an event-driven asynchronous co...

The aim of the experiments described in this paper is to evaluate the use of keyboard and mouse dynamics as an appropriate non-obtrusive sensory input for an system that is sensitive to the affective state of its user. Our motivation for starting this research line has been the lack of tools and methodologies for taking into account this affective...

This paper presents an original approach for building structures that are stable under gravity for the physics-based puzzle game Angry Birds, with the ultimate objective of creating levels with the minimum number of constraints. This approach consists of a search-based procedural level generation method that uses evolutionary algorithms. In order t...

Creating a concurrent and stateless version of an evolutionary algorithm implies changes in its algorithmic model. From the performance point of view, the main challenge is to balance computation with communication, but from the evolutionary point of view another challenge is to keep diversity high so that the algorithm is not stuck in local minima...

This paper analyzes the perception by the audience of Evolutionary Works of Art which were produced by means of the unplugged evolutionary algorithm. The long term goal is to study if genetic operations applied by artists in an evolutionary art work are consistently understood by the audience visiting the art exhibit. Yet, we need to involve the au...

This condensed code and syntax reference book presents the Perl scripting language in a well-organized format designed to be used time and again. It contains an easy-to-read and use guide to Perl 6 for web and software application development. Using this book will give you a feel for the language, as well as an introduction to the different featur...

Resumen-Los simuladores de carreras de coches han sido utilizados durante mucho tiempo como un entorno para probar algoritmos de control autónomo de vehículos. Constituyen un entorno en el para evaluar todo tipo de algoritmos, incluyendo metaheurísticas, como por ejemplo Algoritmos Evolutivos. Sin embargo, el mayor desafío en este tipo de algoritmo...

The concept of Ephemeral Computing is an emergent topic that is currently consolidating among the research community. It includes computing systems where the nodes or the connectivity have an ephemeral and thus unpredictable nature. Although the capacity and computer power of small and medium devices (as smartphones or tablets) are increasing swift...

From the database DBTropes.org, we have created a dataset of films and the tropes that they use, which we have called PicTropes. In this report we provide the descriptive analysis and a further discussion on the dataset PicTropes: The extracted features will help us decide the best values for a future recommendation system and content generator, wh...

Concurrent languages such as Perl 6 fully leverage the power of current multi-core and hyper-threaded computer architectures, and they include easy ways of automatically parallelizing code. However, to achieve more computational capability by using all threads and cores, algorithms need to be redesigned to be run in a concurrent environment; in par...

Genetic algorithms (GA) [8] are currently one of the most widely used meta-heuristics to solve engineering problems. Furthermore, parallel genetic algorithms (pGAs) are useful to find solutions of complex optimizations problems in adequate times [16]; in particular, problems with complex fitness. Some authors [1] state that using pGAs improves the...

Perl 6 is a recently released language that belongs to the Perl family but was actually designed from scratch, not as a refactoring of the Perl 5 codebase. Through its two-year-old (released) history, it has increased performance by several orders of magnitude, arriving recently to the point where it can be safely used in production. In this paper,...

We investigate the convergence speed, accuracy, robustness and scalability of PSOs structured by regular and random graphs with 3 ≤ k ≤ n. The main conclusion is that regular and random graphs with the same averaged connectivity k may result in significantly different performance, namely when k is low.

In this paper we introduce KafkEO, a cloud native evolutionary algorithms framework that is prepared to work with population-based metaheuristics by using micro-populations and stateless services as the main building blocks; KafkEO is an attempt to map the traditional evolutionary algorithm to this new cloud-native format.

Ephemeral computing is a term that describes computing systems whose nodes or their connectivity have an ephemeral, heterogeneous and possibly also unpredictable nature. These properties will affect the functioning of distributed versions of computer algorithms. Such algorithms, which are usually straightforward extensions of sequential algorithms,...

Algorithms for decision support in the battlefield have to take into account separately all factors with an impact of success: speed, visibility, and consumption of material and human resources. It is usual to combine several objectives, since military commanders give more importance to some factors than others, but it is interesting to also explor...

As the development of a software project proceeds, its complexity increases, and this is reflected at several levels, from the file level to the author level. This complexity can be represented via the entropy. In this report we will analyze entropy at the file level, and try to find some correlations, deriving possibly some advice on how to improv...

Issues in repositories are generally tagged with labels that relate to their type, and hint at how to deal with them, which implies that labels will be correlated with repository and issue metrics. In this report we will look at the issues in the Perl 6 repository and the labels they use, and try and draw some conclusions on tag management.

Contributions to a free software repository are made effective through commits, that is, changes in the code. Every commit affects one or several files, and every one is made by a different author. In this report we will look at how these contributions have been distributed throughout the repository history, and what kind of changes have been broug...

After getting a grant from the Perl Foundation for taking care of the repository where Perl 6 documents are hosted, I wanted to run an initial assessment of how this documentation is behaving in terms of community and evolution. One of the compromises I committed to was to engage with at least 2 issues a day, since the number of issues was initiall...

Collectible card games have been among the most popular and profitable products of the entertainment industry since the early days of Magic: The GatheringTM in the nineties. Digital versions have also appeared, with HearthStone: Heroes of WarCraftTM being one of the most popular. In Hearthstone, every player can play as a hero, from a set of nine,...

This work presents an evolutionary approach to optimize the parameters of a Fuzzy-based autonomous driver for the open simulated car racing game (TORCS). Using evolutionary algorithms, we intend to optimize a modular fuzzy agent designed to determine the optimal target speed as well as the steering angle during the race. The challenge in this kind...

Cloud computing is currently the prevailing mode of designing, creating, and deploying complex applications, and it has implied a paradigm shift in all three areas; even if it taps and extends previous concepts such as service oriented, concurrent, and distributed computing, this shift has to be eventually translated to the algorithmic and conceptu...

This paper introduces a procedure based on genetic programming to evolve XSLT programs (usually called stylesheets or logicsheets). XSLT is a general purpose, document-oriented functional language, generally used to transform XML documents (or, in general, solve any problem that can be coded as an XML document). The proposed solution uses a tree re...

This paper introduces a procedure based on genetic pro-gramming to evolve XSLT programs (usually called stylesheets or logicsheets). XSLT is a general purpose, document-oriented functional language, generally used to transform XML doc-uments or, in general, solve any problem that can be coded as an XML document. The proposed solution uses a tree re...