Josep Jorba Esteve

Universitat Oberta de Catalunya | UOC · Computer, Multimedia and Telecommunication Studies

The penetration of connected devices in today’s society has reached overwhelming figures particularly in the last decade. At present connected devices are not only becoming available everywhere, but they are rapidly gaining complexity in terms of their ability to hold significant compute and storage capacities. Thus, computing ceases to be confined...

Aim/Purpose: The current study was conducted to investigate the students’ perceived satisfaction with the use of a semantic-based online laboratory, which provides students with a search mechanism for laboratory resources, such as instruments and devices. Background: The increasing popularity of using online teaching labs, as an important element o...

Data collection of paper: Measuring the effectiveness of an undergraduate online teaching laboratory with semantic mechanism from a student perspective

Over the course of the last decades there has been significant growth in smartphone penetration and capacities. This trend presently complements the rise of IoT and ever complex and smarter connected devices. On balance, considerable contribution has been made to the emergence of unprecedented computing capacity at the edge of the network, which is...

Over the course of the last decades there has been significant growth in smartphone penetration and capacities. This trend presently complements the rise of IoT and ever complex and smarter connected devices. On balance, considerable contribution has been made to the emergence of unprecedented computing capacity at the edge of the network, which is...

Agent-based modeling and simulation (ABMS) is a class of computational models for simulating the actions and interactions of autonomous agents with the goal of assessing their effects on a system as a whole. Several frameworks for generating parallel ABMS applications have been developed taking advantage of their common characteristics, but there i...

Cloud computing emerged as a centralised paradigm that made “infinite” computing resources available on demand. Nevertheless, the ever-increasing computing capacities present on smart connected things and devices calls for the decentralisation of Cloud computing to avoid unnecessary latencies and fully exploit accessible computing capacities at the...

Nueva edición del libro Administración de Sistemas GNU/Linux. OpenAccess bajo Licencia GPL. http://hdl.handle.net/10609/60688

Nueva edición del libro Administración avanzada del sistema operativo GNU/Linux. OpenAccess bajo licencia GPL. http://hdl.handle.net/10609/60686

Developing an efficient parallel application is not an easy task, and achieving a good performance requires a thorough understanding of the program’s behavior. Careful performance analysis and optimization are crucial. To help developers or users of these applications to analyze the program’s behavior, it is necessary to provide them with an abstra...

Performance of memory intensive applications executed on multi-core multi-socket environments is closely related to the utilization of shared resources in the memory hierarchy. Depending on the characteristics of the application, the shared resources utilization can lead to a significant performance degradation. The exploration of different thread...

The evolution of hardware is improving at an incredible rate. However, the advances in parallel software have been hampered for many reasons. Developing an efficient parallel application is still not an easy task. Applications rarely achieve good performances immediately and, therefore, careful performance analysis and optimization are crucial. The...

Currently there is an increasing trend to implement functionalities that allow for the development of applications based on Cloud computing. In education there are high expectations for Learning Management Systems since they can be powerful tools to foster more effective collaboration within a virtual classroom. Tools can also be integrated with th...

The synthesis of digital circuits is a basic skill in all the bachelors around the ICT area of knowledge, such as Computer Science, Telecommunication Engineering or Electrical Engineering. An important hindrance in the learning process of this skill is that the existing educational tools for the design of circuits do not allow the student to valida...

Los sistemas GNU/Linux han alcanzado un grado de madurez significativa, que los hacen perfectamente válidos para su integración en cualquier ambien- te de trabajo, ya sea desde el escritorio del PC personal, un elemento de mo- vilidad (como tabletas o móviles), hasta el servidor de una gran organización. El objetivo principal que nos proponemos es...

Los sistemas GNU/Linux han llegado a un grado de madurez importante que los hace válidos para integrarlos en cualquier ambiente de trabajo, desde el escritorio del PC personal hasta el servidor de una gran empresa. El objeti- vo principal de este curso es introducirnos en el mundo de la administra- ción de los sistemas GNU/Linux. Aprenderemos cómo...

The performance of OpenMP applications executed in multisocket multicore processors can be limited by the memory interface. In a multisocket environment, each multicore processor can present a performance degradation in memory-bound parallel regions when sharing the same Last Level Cache (LLC). We propose a characterization of the performance of pa...

Performance is a main issue in parallel application development. Dynamic tuning is a technique that changes certain applications’ parameters on-line to improve their performance adapting the execution to actual conditions. To perform that, it is necessary to collect measurements, analyze application behavior and carry out tuning actions during the...

This paper describes a simulation–optimization algorithm for the Permutation Flow shop Problem with Stochastic processing Times (PFSPST). The proposed algorithm combines Monte Carlo simulation with an Iterated Local Search metaheuristic in order to deal with the stochastic behavior of the problem. Using the expected makespan as initial minimization...

Data-intensive applications are those that explore, query, analyze, and, in general, process very large data sets. Generally, these applications can be naturally implemented in parallel but, in many cases, these implementations show severe performance problems mainly due to load imbalances, inefficient use of available resources, and improper data...

The prediction of snowdrift formation on high-altitude roads is of interest for road maintenance tasks and planning of ski resorts. In this study a three-dimensional time-dependent computer model of drift formation is presented, that takes into account the effect of natural orographic formations, natural obstacles such as trees, man-made obstacles,...

Note: Available at http://arxiv.org/abs/1310.5850 Remote control systems are a very useful element to control and monitor devices quickly and easily. This paper proposes a new architecture for remote control of Android mobile devices, analyzing the different alternatives and seeking the optimal solution in each case. Although the area of remote con...

In the context of high-altitude mountain ridges, harvesting energy with wind turbines presents new challenges. The results of a computer model solving the Reynolds-Averaged Navier–Stokes equations for incompressible flows above such a ridge are presented in the context of a case study. A theoretical blade-element model of a triblade Horizontal-Axis...

This paper focuses on the Vehicle Routing Problem with Stochastic Demands (VRPSD) and discusses how Parallel and Distributed Computing Systems can be employed to efficiently solve the VRPSD. Our approach deals with uncertainty in the customer demands by considering safety stocks, i.e. when designing the routes, part of the vehicle capacity is reser...

Resource discovery is an important part of distributed computing and resource sharing systems, like grids and utility computing. Because of the increasing importance of decentralized and peer-to-peer environments, characterized by high dynamism and churn, a number of resource discovery mechanisms, mainly based on peer-to-peer techniques, have been...

This paper presents an innovative academic experience regarding the use of PlanetLab—an open large-scale platform over the Internet—in engineering courses on distributed systems. By integrating a live-deployment environment such as PlanetLab into distributed-systems courses, software implementations developed by students can interact with instructo...

One of the main consequences of current HPC systems heterogeneity is that different levels of parallelism should be considered in all phases of parallel application development. Therefore, support tools and, in particular, performance analysis and tuning tools, must also be adapted to manage heterogeneity. A significant step forward in this adaptat...

The recent data deluge needing to be processed represents one of the major challenges in computational field. Available high-performance computing (HPC) systems can be very useful for solving this problem when data can be divided in chunks that can be processed in parallel. However, due to intrinsic characteristics of data-intensive problems, these...

In this paper we propose a technique for measuring the quality of hexahedral Cartesian meshes used to model meso-scale atmospheric circulation in 3D. It is used to verify the progress of a novel method for satisfying the Delaunay criterion for structured hexahedral meshes over complex orography with high gradients and wide gradient variability. Bas...

Data-intensive applications are those that explore, query, analyze, and, in general, process very large data sets. Generally in High Performance Computing (HPC), the main performance problem associated to these applications is the load unbalance or inefficient resources utilization. This paper proposes a methodology for improving performance of dat...

The performance of high performance computing applications depends highly on how they are implemented. However, their runtime behavior is tightly coupled with the re- sources they are allocated such as in which cores the applica tion threads run or in which memory devices their memory space is placed. Thus, depending on their characteristics, appli...

El diseño de circuitos digitales forma parte de las competencias básicas de los nuevos Grados en Ingeniería Informática e Ingeniería de Telecomunicaciones. Un obstáculo importante para el aprendizaje de dichas competencias es que las herramientas académicas existentes para el diseño de circuitos no permiten validar si un diseño se ajusta a la espec...

This paper presents the SR-GCWS-CS probabilistic algorithm that combines Monte Carlo simulation with splitting techniques and the Clarke and Wright savings heuristic to find competitive quasi-optimal solutions to the Capacitated Vehicle Routing Problem (CVRP) in reasonable response times. The algorithm, which does not require complex fine-tuning pr...

http://ocw.uoc.edu/informatica-tecnologia-i-multimedia/administracio-avancada-del-sistema-operatiu-gnu-linux-1/Course_listing

http://ocw.uoc.edu/informatica-tecnologia-y-multimedia/administracion-avanzada-del-sistema-operativo-gnu-linux-1/Course_listing

Los sistemas GNU/Linux han llegado a un grado de madurez importante, que los hacen válidos para integrarlos en cualquier ambiente de trabajo, ya sea desde el escritorio del PC personal, hasta el servidor de una gran empresa. El objetivo principal de este curso es introducirnos en el mundo de la administración de los sistemas GNU/Linux. Aprenderemos...

http://ocw.uoc.edu/informatica-tecnologia-i-multimedia/administracio-de-sistemes-gnu-linux-1/Course_listing

http://ocw.uoc.edu/informatica-tecnologia-y-multimedia/administracion-de-sistemas-gnu-linux/Course_listing

The great success and demand of software tools in education have generated new challenges to improve the functionality and to reduce the limitations of time and availability of bandwidth to process the information. There are a lot of efforts to use distributed technologies in education, in particular Grid computing. The Learning Grid is based on a...

This paper presents a simple decentralized service deployment mechanism that can be used to offer services with high availability by using contributed resources with variable, possibly very low availability. It uses little information about the state of the group, and provides best-effort results. Contributory computer systems are those where users...

Due to the success of web-based systems, the use of Grid technologies have been popularized in the development of learning scenarios supporting scientific applications that enable collaboration and personalization, which can be accessed anytime and anywhere. These Learning frameworks have generated new challenges, since they must develop technologi...

The aim of this work is to present a simulation-based algorithm that not only provides a competitive solution for instances of the Capacitated Vehicle Routing Problem (CVRP), but is also able to efficiently generate a full database of alternative good solutions with different characteristics. These characteristics are related to solution's properti...

This paper proposes an architecture and a set of mechanisms for deploying services in a decentralised contributory system, i.e. a system that runs using only the resources contributed to the community by its members. We present the layers that form our architecture and show the existing technologies that can be used to implement some of them. We sh...

Due to their potential advantages, the use of Grid technologies towards the development of collaborative and personalised learning frameworks has been considerably increased. These learning frameworks can be constructed based on distributed learning services and resources. A problem still unsolved is how to use and integrate low-level learning serv...

During the last decades a lot of work has been devoted to develop algorithms that can provide near-optimal solutions for the Capacitated Vehicle Routing Problem (CVRP). Most of these algorithms are designed to minimize an objective function, subject to a set of constraints, which typically represents aprioristic costs. This approach provides adequa...

Performance is a main issue in parallel application development. Dynamic tuning is a technique that acts over application parameters to raise execution performance indexes. To perform that, it is necessary to collect measurements, analyze application behavior using a performance model and carry out tuning actions. Computational Grids present procli...

After a decade of intensive investigation, peer-to-peer computing has established itself as an accepted research field in the general area of distributed systems. peer-to-peer computing can be seen as the democratization of computing-overthrowing the old regime of hierarchies as in client-server systems-largely brought about by last-mile network im...

In this paper we present a proposal of the architecture for a system which allows the deployment of services in a group of computers, connected in a peer-to-peer fashion. This architecture is divided in layers, and each of them contains some components which offer specific functions. By putting them together, we obtain a system with desirable chara...

Como consecuencia del rápido desarrollo de Internet, la programación distribuida está haciéndose rápidamente popular día a día. Internet provee de los primeros mecanismos básicos para una infraestructura global en las aplicaciones distribuidas, un espacio de nombres global (basado en las URL) y protocolos de comunicación globales (TCP/IP). La mayor...

Due to their potential advantages, the use of Grid technologies toward the development of collaborative and personalized learning frameworks has been considerably increased. These learning frameworks can be constructed based on the distributed learning services and resources available in a learning Grid environment. A problem still unsolved is how...

Learning Grid services are the fundamental component of learning systems based on Grid Technology and represent functionalities that can be easily reused without knowing the details of how services have been implemented. Semantic Web Service technology promises to automate web service discovery, composition and integration, tasks that currently nee...

This work proposes an initial model for the automatic composition of Grid based learning services based on the semantic capabilities and metadata of e-learning frameworks. There are three principal motivations for Learning Grid Services Composition: build a more powerful service using basic existing services, fulfill service requester’s requiremen...

In the implementation of e-learning frameworks, a problem still unsolved is how to use and integrate low-level learning services to compose more complex high-level services or tools that make sense to both tutors and learners. In that sense semantic description of Grid learning Services appears like a powerful tool to be used for discovering and m...

In this paper we present the design of a system which allows service deployment in a small-sized group of computers distributed through the Internet. These groups are formed by users who share a common interest, and voluntarily yield their own resources for the achievement of the collaborative activities of the group. Having enough resources contri...

DIsponible: http://ocw.uoc.edu/informatica-tecnologia-y-multimedia/proyecto-de-direccion-de-sistemas-de-informacion/Course_listing El desenvolupament de projectes en administració de xarxes i sistemes operatius en entorns de programari lliure és similar a qualsevol altre tipus de projecte amb algunes subtils diferències. És necessari, per a arriba...

Performance is a crucial issue of parallel/distributed applications. One kind of useful tools, in this context, are the automatic performance analysis tools, that help developers in some of the phases of the performance tuning process. KappaPI 2 is an automatic performance tool, with open knowledge about typical inefficiencies in message passing ap...

Disponible: http://ocw.uoc.edu/informatica-tecnologia-i-multimedia/projecte-en-administracio-de-xarxes-i-sistemes-operatius-basats-en-gnu-linux/materials/ El desenvolupament de projectes en administració de xarxes i sistemes operatius en entorns de programari lliure és similar a qualsevol altre tipus de projecte amb algunes subtils diferències. És...

Grid technology has emerged as a powerful tool to increase the capabilities of e-learning frameworks. Learning services are fundamental components representing functionalities that can be easily reused without knowing the details of how services have been implemented. On the one hand, a problem that still remains unsolved is how to use and integrat...

Grid technology has emerged as a powerful tool to increase the capabilities of e-learning frameworks. Learning services are fundamental components representing functionalities that can be easily reused without knowing the details of how services have been implemented. On the one hand, a problem that still remains unsolved is how to use and integrat...

Performance is a crucial issue in parallel/distributed applications. Designers and developers ex- pect their applications to reach certain performance indexes to meet the expectations of high per- formance computing systems. Therefore, parallel application developers are obliged to not only to analyze the application itself, but also the software l...

Message passing libraries offer the programmer a set of primitives that are not available in sequential programming. Developing applications using these primitives as well as application performance tuning are complex tasks for non-expert users. Therefore, automatic performance analysis tools that help the user with performance analysis and tuning...

Message passing libraries offer the programmer a set of primitives that are not available in sequential programming. Developing applications using these primitives as well as application performance tuning are complex tasks for non-expert users. Therefore, automatic performance analysis tools that help the user with performance analysis and tuning...

Parallel computing is a promising approach that provides more powerful computing capabilities for many scientific research fields to solve new problems. However, to take advantage of such capabilities it is necessary to ensure that the applications are successfully designed and that their performance is satisfactory. This implies that the task of t...

The classical way of tuning parallel/distributed applications is based on the analysis of the monitoring information obtained from an execution of the application. However, this "measure and modify" approach is not feasible when the applications have a dynamic behavior. In this case, another approach is required to accomplish performance expectatio...

The use of distributed programming libraries is very common in the development of scientific and engineering applications. These libraries, from message passing libraries to numerical libraries, are designed in a very general way to be useful for a wide range of applications. Therefore, there are several polices that must be adapted to the particul...

PCs and Workstations clusters are becoming more popular everyday. In many cases these systems are considered as part of a wider system for meta or GRID computing purposes. The management, administration and use of this systems present several difficulties due to the need to access different systems located at remote sites. A new architecture for ma...

This paper summaries experiences designing and developing a parallel/distributed simulator for existing models of forest fire propagation using PVM. The methodology used to parallelise the application is described. Results obtained for the parallelisation on different platforms are presented: clusters of SUN workstations and PCs, and one parallel m...

Forest fire is one of the most critical environmental risks in all the Mediterranean Countries. The fight against these emergencies requires useful tools to predict the propagation and behaviour of forest fire in order to take the best decisions. It means it is necessary to know the propagation and behaviour of the forest fire in advance to act in...

Esta asignatura trata de la problemática, organización y aplicación de los sistemas distribuidos. Las aplicaciones distribuidas son sistemas formados por algunos, varios o muchos ordenadores interconectados en una red y con procesos que interaccionan entre sí de una manera compleja, compartiendo recursos y servicios.

Aquesta assignatura tracta de la problemàtica, organització i aplicació dels sistemes distribuïts. Les aplicacions distribuïdes són sistemes formats per alguns, diversos o molts ordinadors interconnectats en una xarxa i amb processos que interaccionen entre si d'una manera complexa, compartint recursos i serveis. Esta asignatura trata de la problem...

Els sistemes GNU/Linux han arribat a un grau de maduresa important que els fa vàlids per a integrar-los en qualsevol ambient de treball, tant si és l'escriptori del PC personal, com el servidor d'una gran empresa. L'objectiu principal d'aquest curs és introduir-nos al món de l'administració dels sistemes GNU/Linux. Aprendrem com proporcionar des de...