Isaac Lera

• PhD Doctor in Computer Science
• University of the Balearic Islands

This study compares three evolutionary algorithms for the problem of fog service placement: weighted sum genetic algorithm (WSGA), non-dominated sorting genetic algorithm II (NSGA-II), and multiobjective evolutionary algorithm based on decomposition (MOEA/D). A model for the problem domain (fog architecture and fog applications) and for the optimiz...

Orchestrating next gen applications over hterogeneous resources along the Cloud-IoT continuum calls for new strategies and tools to enable scalable and application-specific managements. Inspired by the self-organisation capabilities of bacteria colonies, we propose a declarative, fully decentralised application management solution, targeting pervas...

We propose a framework designed to tackle a multi-objective optimization challenge related to the placement of applications in fog computing, employing a deep reinforcement learning (DRL) approach. Unlike other optimization techniques, such as integer linear programming or genetic algorithms, DRL models are applied in real time to solve similar pro...

The aim of this study was to see whether student participation increased when mobile devices were used in the classroom. We measured the amount of student participative actions when the Socrative tool was used and when it was not used. Our experiment involved a total of 192 students, corresponding to 4 different subjects of Computer Engineering at...

This paper presents a platform to facilitate the deployment of applications in Internet of Things (IoT) devices. The platform allows to the programmers to use a Function-as-a-Service programming paradigm that are managed and configured in a Platform-as-a-Service web tool. The tool also allows to establish interoperability between the functions of t...

Fog computing architectures distribute computational and storage resources along the continuum from the cloud to things. Therefore, the execution of services or the storage of files can be closer to the users. The main objectives of fog computing domains are to reduce the user latency and the network usage. Availability is also an issue in fog arch...

The increasing complexity of fog computing environments calls for efficient resource optimization techniques. In this paper, we propose and evaluate three distributed designs of a genetic algorithm (GA) for resource optimization in fog computing, within an increasing degree of distribution. The designs leverage the execution of the GA in the fog de...

The organization of fog devices into fog colonies has reduced the complexity management of fog domains. One of the main influencing factors on this complexity is the large number of devices, i.e. the high scale level of the infrastructure. Fog colonies are subsets of fog devices that are managed independently from the other colonies. Thus, the numb...

Fog computing is a new computational paradigm that emerged from the need to reduce network usage and latency in the Internet of Things (IoT). Fog can be considered as a continuum between the cloud layer and IoT users that allows the execution of applications or storage/processing of data in network infrastructure devices. The heterogeneity and wide...

This paper presents a method that generates a hierarchical user mobility model from the analysis of the data available from Wi-Fi connections. The data obtained from the Wi-Fi infrastructure is defined in terms of the coverage areas of the access points that the users move through. These access points are recursively grouped into different levels o...

Fog Computing is a new computational paradigm that emerges from the need of reducing the network usage and latency in Internet of Things (IoT). Fog can be understood as a continuum between the Cloud layer and the IoT users that allows to execute applications or store/process data in the networks devices of the infrastructure. This paper aims to rev...

Orchestrating next-gen applications over heterogeneous resources along the Cloud-IoT continuum calls for new strategies and tools to enable scalable and application-specific managements. Inspired by the self-organisation capabilities of bacteria colonies, we propose a declarative, fully decentralised application management solution, targeting perva...

Osmotic computing encompasses emerging Cloud‐Internet of Things (IoT) computing paradigms, by featuring the possibility for application services to adapt into different functionally equivalent flavours, depending on the contextually available resources and on specific requirements of running applications. This article proposes a fully decentralised...

En este Trabajo de Final de Grado del Grado de Ingeniería Informática se realiza un estudio y una experimentación sobre la aplicación de los algoritmos de aprendizaje automático por refuerzo en problemas de búsqueda. El problema tratado consiste en crear un agente inteligente que se encuentra en un entorno y que debe ser capaz de alcanzar un objeti...

Fog computing aims at extending the cloud towards the Internet of things so to achieve improved quality of service and to empower latency‐sensitive and bandwidth‐hungry applications. The fog calls for novel models and algorithms to distribute multiservice applications in such a way that data processing occurs wherever it is best placed, based on bo...

Fog computing is a paradigm that extends the Cloud to intermediate network devices with computational and storage capacities. This allows the execution of applications closer to edge devices and end-users by allocating services in those intermediate devices. The placement of those services has an influence on the performance of the fog architecture...

Managing multi-service applications on top of dynamic and heterogeneous Fog infrastructures is intrinsically challenging and requires suitable tooling to support decision-making. Indeed, bad service deployment decisions can lead to unsatisfactory application QoS, to waste of computing resources or money, and to application downtime. In this paper,...

The use of Cloud computing for the development of Internet of Things (IoT) applications has emerged during the last years. But there is a lack of a platform which facilitates the deployment and the interoperability of this type of applications. This paper presents a platform to facilitate the deployment of Cloud-based applications to devices in IoT...

A decentralized optimization policy for service placement in fog computing is presented. The optimization is addressed to place most popular services as closer to the users as possible. The experimental validation is done in the iFogSim simulator and by comparing our algorithm with the simulator’s built-in policy. The simulation is characterized by...

Fog computing architectures distribute computational and storage resources along the continuum from the cloud to things. Therefore, the execution of services or the storage of files can be closer to the users. The main objectives of fog computing domains are to reduce the user latency and the network usage. Availability is also an issue in fog arch...

Curricula vitae are widely used as the main mechanisms for evaluation of researchers. They also reflect a fraction of the data about the research activity of an organization and geographic area. The nature of the academic world causes researchers to have to continuously keep the information updated. There are tools to help manage this information,...

We propose a fog computing simulator for analysing the design and deployment of applications through customized and dynamical strategies. We model the relationships among deployed applications, network connections and infrastructure characteristics through complex network theory, enabling the integration of topological measures in dynamic and custo...

We propose a fog computing simulator for analysing the design and deployment of applications through customized and dynamical strategies. We model the relationships among deployed applications, network connections and infrastructure characteristics through complex network theory, enabling the integration of topological measures in dynamic and custo...

This study compares three evolutionary algorithms for the problem of fog service placement: weighted sum genetic algorithm (WSGA), non-dominated sorting genetic algorithm II (NSGA-II), and multiobjective evolutionary algorithm based on decomposition (MOEA/D). A model for the problem domain (fog architecture and fog applications) and for the optimiz...

Fog computing aims at extending the Cloud towards the IoT so to achieve improved QoS and to empower latency-sensitive and bandwidth-hungry applications. The Fog calls for novel models and algorithms to distribute multi-component applications in such a way that data processing occurs wherever it is best-placed, based on both functional and non-funct...

Fog computing extends the cloud to where things are by placing applications closer to the users and Internet of Things (IoT) devices. The placement of those applications, or their services, has an important influence on the performance of the fog architecture. Improving the availability and the latency of the applications is a challenging task due...

An approach to optimize the deployment of microservices-based applications using containers in multi-cloud architectures is presented. The optimization objectives are three: cloud service cost, network latency among microservices, and time to start a new microservice when a provider becomes unavailable. The decision variables are: the scale level o...

This work addresses the optimization of file locality, file availability, and replica migration cost in a Hadoop architecture. Our optimization algorithm is based on the Non-dominated Sorting Genetic Algorithm-II and it simultaneously determines file block placement, with a variable replication factor, and MapReduce job scheduling. Our proposal has...

Resource management is a key factor in the performance and efficient utilization of cloud systems, and many research works have proposed efficient policies to optimize such systems. However, these policies have traditionally managed the resources individually, neglecting the complexity of cloud systems and the interrelation between their elements....

The use of containers in cloud architectures has become widespread, owing to advantages such as limited overheads, easier and faster deployment, and higher portability. Moreover, they present a suitable architectural solution for the deployment of applications created using a microservice development pattern. Despite the large number of solutions a...

Linked Open Data initiative, based on the open publication of datasets, provides new mechanisms for the development of novel services, and through rigorous data analysis new indicators for government strategies. We contribute with a linked open portal to integrate curriculum data of our academic staff. We analyse our experience in the creation of t...

The exploitation of high volume of geolocalized data from social sport tracking applications of outdoor activities can be useful for natural resource planning and to understand the human mobility patterns during leisure activities. This geolocalized data represents the selection of hike activities according to subjective and objective factors such...

Four seasons, spring, and summer networks in GEXF format. (ZIP)

Detailed information of raw data, and hiking activity networks. (PDF)

The exploitation of high volume of geolocalized data from social sport tracking applications of outdoor activities can be useful for natural resource planning and to understand the human mobility patterns during leisure activities. This geolocalized data represents the selection of hike activities according to subjective and objective factors such...

Smart home refers to the application of various technologies to semi-unsupervised home control It refers to systems that control temperature, lighting, door locks, windows and many other appliances. The aim of this study was to design a system that will use existing technology to showcase how it can benefit people with disabilities. This work uses...

The energy consumption of Cloud Computing systems is one of the current concerns of systems architects. In order to reduce the energy consumption, they have provided techniques which go through the design of locations for data centres, together with techniques for the proper management of resources, taking into account the energy consumption of the...

The aim of this study was to see whether student participation increased when mobile devices were used in the classroom. We measured the amount of student participative actions when the Socrative tool was used and when it was not used. Our experiment involved a total of 192 students, corresponding to 4 different subjects of Computer Engineering at...

We have transformed five years of curriculum data of our academic staff from relational databases to a semantic model. Thanks to semantic queries, capabilities of NoSQL models, inference reasoners and data mining techniques we obtain knowledge that it improves the personal management of curriculum data, the quality and efficiency of exploitation ta...

Among the various techniques and group dynamics, one extensively used is role-playing, in which the members of the group, in partor in whole, represent certain facts or issues that will be studied and that the technique helps to understand better. In this paper, we illustrate the technique of role-playing and its practical application in University...

In this paper, we are showing how Information Technology (IT) governance frameworks contribute to the implementation of the key principles of the good corporate governance, particularly, in the public sector. We demonstrate that there are numerous links, explicitly and implicitly expressed through a set of IT governance instruments, matching the pr...

Web 2.0 systems are more unpredictable and customizable than traditional web applications. This causes that performance techniques, such as web caching, limit their improvements. Our study was based on the hypotheses that the use of web caching in Web 2.0 applications, particularly in content aggregation systems, can be improved by adapting the con...

This paper describes a JMeter extension created to allow for web structure mining process. This type of mining process is very important, for example, in the field of web performance engineering and web development validations. The extension allows users to define the HTML tags that wrap the content units and it creates a graph model to represent t...

This paper addresses the problem of synthesizing an ontology by defining prunning measures based on OWL axioms. From a deep structural and axiomatic analysis of current ontologies, we have defined a set of basic measures of selection of important elements that it has a linear computational cost.

Ontology Matching (OM) consists of set of processes that decide and establish if ontology elements share lexical or semantic relationships. For a correct alignment, when we establish semantic relationships, it is necessary to find out the meaning of the elements that depends on the context. In this paper, we propose an extension of OWL called OWL-M...

The integration process using UML Profile for Schedulability, Performance, and Time Specification (SPT) or MARTE specification presents some deficiencies due to the inability to formalize the representation criteria and to relate information in a transparent way between the outputs of performance models and software designs. The drawbacks of FR and...

We present a new unsupervised algorithm which uses external resources and does not require any training to determine the sense more suitable of an ontology concept. We try to find out lexical coincidences among terms of both resources: ontology and WordNet. Through a voting system, we give weight each sense according to measurable parameters and lo...

In this paper we proposed a computational model that automatically integrates a knowledge base with an affective model. The knowledge base presented as a semantic model, is used for an accurate definition of the emotional interaction of a virtual character and their environment. The affective model generates emotional states from the emotional outp...

We propose a knowledge semantic model that allows the definition of a generic and interactive virtual environment with be-lievable characters. We also introduce an affective model that determines the emotional state of a character according to his personality traits and the experienced emotions. To evidence the emotional states, we attribute them a...

The ontology mapping appears in many application domains and its resolution is complex due to the different ways to represent the information. Our approach is based on the creation of a new structure that contains the main concepts of an ontology. These concepts define the ontology purpose and its granularity. Furthermore, we increase these terms u...

In the computer science community there is a growing interest in the field of Ambient Intelligent Systems. This systems surround their human users with computing and networking technology unobtrusively embedded in their environment. This technology is aimed to provide the users with useful information and to take action to make the environment more...

The ontology mapping problem is crucial to efficient useful information exchange. This problem appears in many application domains and its resolution is complex due to the different ways to represent the information. In this paper, our approach is based on the creation of a new structure. It is called Semantic Axis Header (SAH). It contains the mai...

Semantic web is mainly addressed to distributed web systems development. The semantic web organizes the information in a way that it is possible to find it even the amount of data is enormous. The semantic web provides a way to transform the information into knowledge by storing the data in concepts related by their meaning. This work-in- progress...

Several techniques and applications have been proposed to aid the decision taking process in the system performance domain. Most of these techniques have depicted the performance model of systems through annotations of performance measurements coming from specific software descriptive syntactical languages. However, the semantic representation of p...

Several techniques and applications have been proposed to aid the decision taking process in the system performance domain. Most of these techniques have depicted the performance model of systems through annotations of performance measurements coming from specific software descriptive syntactical languages. However, the semantic representation of p...

Web performance engineering techniques are classically based on the augmented description of the model regarding performance annotations. However, these annotations are only related with the syntactical view of the system. The next generation of performance assessment tools for intelligent systems would be capable of acquiring knowledge and even re...

This paper brings together the performance assessment of ambient intelligence architectures systems with ontology engineering. Thus, firstly appropriate description methods for distributed intelligent applications are summarized. Derived from the system characterization, typical software performance engineering techniques are based on the augmented...

To facilitate the Human Computer Interaction will be needed to create a friendly interface in AmI. Thus, in this work we propose a semantic knowledge model to represent facial emotions of a virtual character. These emotions depend on the personality, preferences, goals of the character and the environment events. The virtual character’s emotions ar...

We present a computational affective model that deter-mines the emotional state of a character according to his personality traits and the experienced emotions. Emotions are produced by events of the world that surrounds the character, as well as other personal elements represented by a generic knowledge semantic model. To evidence the emotional st...