Pedro Álvarez

University of Zaragoza | UNIZAR · Department of Computing and Systems Engineering

Process mining techniques extract knowledge from event logs within organizations to understand and improve the behavior of their business processes. These techniques utilize a wide range of methods to automatically generate process models from event log data, simplify these models, calculate various indicators to optimize performance, and visualize...

italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Contribution: This article proposes and applies a new systemic 3-D model and a methodology for empathy awareness and development, integrating different partial approaches found in the literature for developing empathy as a transversal competence. Back...

Wearable technology is playing an increasing role in the development of user-centric applications. In the field of sports, this technology is being used to implement solutions that improve athletes’ performance, reduce the risk of injury, or control fatigue, for example. Emotions are involved in most of these solutions, but unfortunately, they are...

In this work, we present a complete system to produce an automatic linguistic reporting about the customer activity patterns inside open malls, a mixed distribution of classical malls joined with the shops on the street. These reports can assist to design marketing campaigns by means of identifying the best places to catch the attention of customer...

The music emotions can help to improve the personalization of services and contents offered by music streaming providers. Many research works based on the use of machine learning techniques have addressed the problem of recognising the music emotions during the last years. Nevertheless, the results obtained are only applied on small-size music repo...

In the curriculum of a Computer Engineering program, concepts like parallelism, concurrency, consistency, or atomicity are usually addressed in separate courses due to their thoroughness and extension. Isolating such concepts in courses helps students not only to focus on specific aspects, but also to experience the reality of working with modern c...

In this work we present a method to estimate the activity patterns made by shoppers in open malls based on localization information and process mining techniques. We present our smart phone application for logging information from sensors and a process mining system to discover what kind of activity pattern is made by the shoppers based in the key...

The online music streaming providers offer powerful personalization tools for recommending songs to their registered users. These tools are usually based on users’ listening histories and tastes, but ignore other contextual variables that affect users while listening to music, for example, the user’s mood. In this paper, a Web-based system for gene...

Music can produce a positive effect in runners’ motivation and performance. Nevertheless, these effects vary depending on the user’s location, the emotions that she/he feels at each moment or the type of training session. In this paper, a context and emotion-aware system for the recommendation and playing of Spotify songs is presented. It consists...

Improvements to customer experience give companies a competitive advantage, as understanding customers' behaviors allows e-commerce companies to enhance their marketing strategies by means of recommendation techniques and the customization of products and services. This is not a simple task, and it becomes more difficult when working with anonymous...

The recognition of emotions for annotating large-size music datasets is still an open challenge. The problem lies in that most of the solutions require the audio of the songs and user/expert intervention during certain phases of the recognition process. In this paper, we propose an automatic solution for overcoming these drawbacks. It consists of a...

Para el alumnado de Ingeniería Informática resulta de gran interés alcanzar una visión global de los diferentes niveles de abstracción que permiten entender y explotar un sistema informático, sobretodo cuando en las fronteras hardware-software intervienen conceptos complejos como el paralelismo, la concurrencia, la consistencia o la atomicidad. Sin...

For students of any Computer Engineering program, attaining an integrated vision of the different abstraction levels is paramount to fully understand and exploit a computer system, especially when tough topics such as parallelism, concurrency, consistency, or atomicity are involved at the hardware-software frontiers. However, the structure of typic...

The increasing demand of computing resources has boosted the use of cloud computing providers. This has raised a new dimension in which the connections between resource usage and costs have to be considered from an organizational perspective. As a part of its EC2 service, Amazon introduced spot instances (SI) as a cheap public infrastructure, but a...

People that practice running use to listen to music during their training sessions. Music can have a positive influence on runners’ motivation and performance, but it requires selecting the most suitable song at each moment. Most of the music recommendation systems combine users’ preferences and context-aware factors to predict the next song. In th...

This paper presents innovations to stimulate the autonomy of engineering students by using different active methodologies. The strategies designed to address this problem are based on analyzing students’ learning styles and incorporating specific tools into teaching practice, such as "M-eRoDes", which supports the automatic evaluation and feedback...

Music can have a positive influence on long-distance runners’ motivation and performance. It requires selecting the most suitable music by considering the runner’s physiological data, the type of training session and the geographical and environmental conditions under which the activity is done. In this context, we are interested in studying the ru...

The recent development in scientific computing related areas has shown an increasing interest in scientific workflows because of their abilities to solve complex challenges. Problems and challenges that were too heavy or time-consuming can be solved now in a more efficient manner. Scientific workflows have been progressively improved by means of th...

The decision of migrating a service to a cloud-based system must take into consideration many different aspects. Among them, economical costs is one of the most important. This paper describes how a computing-intensive service, based on a bag-of-tasks approach, has been migrated from a grid infrastructure to the Amazon Elastic Compute Cloud (EC2) i...

The increasing demand of computing resources has boosted the use of cloud computing providers. This has raised a new dimension in which the connection between resource usage and costs has to be considered from an organizational perspective. As a part of its EC2 service, Amazon introduced spot instances (SIs) as a cheap public infrastructure, but at...

Online shopping is becoming more and more common in our daily lives. Understanding users’ interests and behaviour is essential in order to adapt e-commerce websites to customers’ requirements. The information about users’ behaviour is stored in the web server logs. The analysis of such information has focused on applying data mining techniques wher...

Formal verification plays a crucial role when dealing with correctness of systems. In a previous work, the authors proposed a class of models, the Unary Resource Description Framework Petri Nets (U-RDF-PN), which integrated Petri nets and (RDF-based) semantic information. The work also proposed a model checking approach for the analysis of system b...

The economic cost is a decisive factor that influences the migration of an application to a cloud infrastructure. Once the migration has been decided, the cost of cloud resources that will be hired to run the application must be minimized considering the application and user constraints. In this paper, we propose a method to determine the cheapest...

The Universia repository is composed of more than 15 million of educational resources. The lack of metadata describing these resources complicates their classification, search and recovery. To overcome this drawback, it was decided to semantically annotate the available educational resources using the ADEGA algorithm. For this objective, we selecte...

When heterogeneous computing resources are integrated to create more powerful execution environments, new scheduling strategies are necessary to allocate work units to available resources. In this paper we apply simulation results to schedule the execution of scientific workflows in a resource integration platform. A simulator built upon Alea and G...

The business goals of an enterprise process are traced to business process models with the aim of being carried out during the execution stage. The automatic translation from these models to fully executable code that can be simulated and round-trip engineered is still an open challenge in the Business Process Management field. Model-driven Enginee...

Cloud has emerged as an alternative to clusters and grids. Its adoption as an execution environment capable of supporting the high requirements of scientific computations is still an open question. In a previous work, the authors conducted successfully a practical experience of taking advantage of clusters and grids to solve a semantic annotation p...

Cloud computing infrastructures are becoming a very powerful mean for the implementation of reliable and extensible computing systems. In this paper, we evaluate the viability of migrating a framework for the execution of (scientific) workflows from a cluster-based to a cloud-supported implementation. As a first step, we focus on the viability of a...

From a computational point of view, the semantic annotation of large-scale data collections is an extremely expensive task. One possible way of dealing with this drawback is to distribute the execution of the annotation algorithm in several computing environments. In this paper, we show how the problem of semantically annotating a large-scale colle...

In the last years, many institutions have provided themselves with cluster and Grid infrastructures either for intensive computation or research objectives. Each infrastructure having its own and different management operating software, the integration of different platforms becomes a hard and complicated task. Solving the interoperability problem...

Semantic business processes require new analysis techniques able to deal with behavioral properties that also consider semantic aspects. In this paper, a model checking method is introduced including semantic aspects in both the model description and the formula to be verified. In addition, Unary resource description framework (RDF) annotated Petri...

The business goals of an enterprise process are traced to business process models with the aim of being carried out during the execution stage. The automatic translation from these models to fully executable code which can be simulated and round-trip engineered is still an open challenge in the Business Process Management field. Model-driven Engine...

Service-oriented computing provides a suitable technological foundation for developing and executing dynamic business processes. However, most current approaches for composition languages and architectures for dynamic process integration do not provide the flexibility and dynamism required by interorganisational evolving environments. In this work,...

One of the basic problems in (semantic) business process management concerns the behavioral analysis at design time so that only correct processes are exposed. Although this analysis requires the semantic propagation of data and system preconditions through processes and between processes to be considered, some concrete data are usually obtained at...

In the coming years, one of the challenges for business processes is to obtain a high degree of flexibility and ability to adapt to the changing contexts. Two key elements for achieving this are the use of Semantic Web technologies and the possibility of decoupling the business and the interaction aspects in a business process. Nevertheless, these...

Scientific workflow systems often operate in unreliable environments, and have accordingly incorporated different fault tolerance techniques. One of them is the checkpointing technique combined with its corresponding rollback recovery process. Different checkpointing schemes have been developed and at various levels: task- (or activity-) level and...

The use of the Service-Oriented Architecture paradigm (SOA) as an architectural model together with the use of Web services technologies have spread out widely in the world of business processes. The Business Execution Language, BPEL, represents one of the most common orchestration languages used to build SOA compositions. Using BPEL, a business pr...

Semantic business processes require new analysis techniques able to deal with behavioral properties that also consider semantic aspects. In this paper, a model checking method is introduced including semantic aspects in both the model description and the formula to be verified. Finally a prototype of the model checker based on the use of RDF and SP...

Scientific workflow systems often operate in highly unreliable, heterogeneous and dynamic environments, and have accordingly incorporated different fault tolerance techniques. We propose an exception-handling mechanism, based on techniques adopted in programming languages, for modifying at run-time the structure of a workflow. In contrast to other...

One of the basic problems in semantic business management concerns the validation of semantic business processes. This paper introduces the Unary RDF Annotated Petri net systems as a formalism to model and analyze business processes with RDF annotations to deal with semantic information from both, data and control flow points of view. In addition,...

Interaction protocols are essential elements for the integration of business processes. Usually, protocols have been agreed in advance by the participating organizations, playing each participant a predefined role. However, it is also possible that processes need to use/to impose a concrete interaction pattern. The question for another process is t...

Web-based applications require a flexible adaptation to the changing environment. One of the elements to achieve this aim is based on the flexible use of interaction protocols. Another key element is the separation between business process logic and interaction actions, so that runtime-depending parameters can influence the selection and parametriz...

ABSTRACT Scientific workflows generally involve the distribution of tasks to distributed resources, which may exist in different admin- istrative domains. Such a distribution may,lead to faults that may arise at different levels: application level, enact- ment level, and resource management level, for instance. Detecting these faults, and subsequen...

Dynamic and flexible service composition and interactionare a must in service oriented computing (SOC) scenarios. In this paper the authors present an extension to a previous work, the DENEB platform for the development and execution of Web processes, allowing Web processes to acquire and execute new interaction protocols at runtime. This makes DEN...

There is growing interest in promoting interoperability among the many different existent grid initiatives. The requirements for interlinking of grids have already been studied from a general point of view. In this paper, we analyse current practice in grid interactions and show evidence of how grid interactions may represent a barrier for interlin...

As the requirements for e-business activities have become more complex, the need for adaptable e-marketplaces has increased in the last years. Not only must configurable e-marketplaces support the exchange of heterogeneous information among trading processes, but also the execution of different e-negotiation protocols over the same instance. It is...

Because of the nature of the Grid, Grid application systems built on traditional software development techniques can only interoperate with Grid services in an ad hoc manner that requires substantial human intervention. In this paper, we introduce Vega, a pure service-oriented Grid workflow system which consists of a set of loosely coupled services...

In this paper, a first step toward the use of Artificial Intelligence tools (namely proof assistants) in the formal analysis of programs for Web services coordination is presented. This first attempt consists in the formal modeling of a system with transactional capabilities. The model is devised on a variant of the well-known Linda model for gene...

Recently, coordinationmiddleware systemshave evolved in order to describe coordination protocols in business process scenarios. This evolution proposes the use of three main components, being one of them a message broker to handle collaborative interactions among business processes. In a previous work, we proposed a framework for coordination in op...

The core functionality of Web-service middlewares tries to wrap existing business logics and make them accessible as Web services. Recently, well-known standardization initiatives have proposed some high-level declarative languages for the description of coordination protocols and the implementation of coordination middlewares. In parallel to these...

In this work, we report an experience that illustrates the interplay between formal methods and real software development. Starting from a Web-enable Coordination Service (WCS) based on JavaSpaces technology which had been successfully used in an industrial project, we built a formal model for the system in order to study its properties; specifical...

A new generation of open Business Process Management (BPM) systems based on the service-oriented architecture and Web service technologies has recently emerged. The general tendency for these systems should be governed by the integration of independent Web-service specifications. Web services requirements guide the description, execution and choreo...

Web service coordination and composition have become a central topic for the development of Internet-based distributed computing. A wide variety of different standards have been defined to deal with the composition of Web services (usually represented as workflows) and the execution of coordination protocols. On the other hand, some relevant resear...

One of the essential components for the construction of a geographic spatial data infrastructure at a regional, national or global level is the geographic information catalog server. But, for the catalog to be a useful component, it must enable access to geographic information metadata independently of the nature of search client applications, in o...

Web services coordination has become a central topic for further development of Internet-based distributed computing. One approach to this coordination task is supported by generative communication, and more specifically by some implementations of the Linda model as JavaSpaces. However, when applying these coordination strategies to real projects,...

The Water Framework Directive requires the European Commission to be provided with certain geographic information in the form of maps. The working group in GIS (GIS-GW) was formed to provide common guidance in implementing the GIS elements, presenting a set of best practices that taken to their full extent should led to the creation of an SDI that...

Internet has succeeded as a global information system mainly because of its availability and openness, and the simplicity of its stan- dards and protocols. However, the current use of Internet as universal middleware has clearly shown the lack of maturity of Web technology to support distributed applications, which involve communication, cooper- at...

Different standard middleware proposals have emerged to provide computing models and communication among components in open distributed systems. Nowadays, Internet is becoming an increasingly relevant alternative to middleware platforms, due to the success of Web services in solving problems of application-to-application integration in distributed...

The use of open technologies and standards have made easier the integration of Web services into end-applications. These interoperable services have been organized on distributed architectures over Internet in accordance with shared functional principles. But these Web-service architectures have not resolved the distributed computing difficulty in...

In modern computer environments used for vehicle location, several users, with different technical or managerial goals, may be interested in the real-time data coming from the global positioning systems (GPS) sensors embedded in the vehicle or may want direct access to the GPS system itself. On the other hand, connections to these remote GPS device...

En este trabajo se aborda el problema de visualizar grandes repositorios de imágenes de satélite a través de una red, ya sea una intranet o Internet. Los problemas vienen dados por las limitaciones a la velocidad de transferencia de datos impuestas por la red, lo que conlleva importantes limitaciones al tamaño de la información a transmitir. Este a...

This paper presents a Java approach to develop a geologic-mining information system. User requirements address system features such as GIS visualization and modification, interoperation with tabular data, distributed concurrent access to read and modify GIS data still maintaining, and support for internet browsers. The paper shows the advantages of...

Resumen En el mundo de la informática es fundamental el proceso de abstracción. Sin embargo los conceptos abstractos son difíciles de asimilar, y aún más difícil adquirir el propio mecanismo de abstracción. Creemos que el uso de algunos recursos informales (lo que llamamos muletas y muletillas) puede facilitar la comprensión de la informática en al...

This paper illustrates the IDEZar project, a project that mainly consists in the development of a local Spatial Data Infrastructure (SDI) in Zaragoza (Spain) in order to get an improved management of spatial data available in the City Council of Zaragoza and to provide several online services to its citizens. The authors detail in this paper the in...

Resumen Los estudios de Postgrado suelen ser estudios de especialización. No obstante, esta especialización puede abarcar muchos campos como ocurre en el caso del Postgrado en Informática de la Universidad de Zaragoza. Dar cabida a aspectos tan específicos como son los propios de Ingeniería del Software dentro de este Postgrado resulta complejo ya...

In modern computer environments used for vehicle location several users, with different technical or managerial goals, may be interested in the real time data coming from the GPS sensors embedded in the vehicle or may want direct access of the GPS system itself. On the other hand, the connection to these remote GPS devices may be also strategically...

In this paper a fleet tracking and monitoring system enabled to Internet is presented. For this kind of systems, it is necessary to integrate different technologies to offer the required basic functionality (wireless communication, GPS, GIS,…). These technologies enable the acquisition of vehicle locations in real time and the visualization of vehi...

SUMMARY In this paper, the service-based architecture of a framework for the management of natural disasters is presented. This proposal combines last trends in the design of Geographic Information Systems, namely web service technologies and OGC standards (including the Sensor Web), with Multicriteria Decision Analysis techniques, which enable the...

This paper shows the infrastructure to provide location-based services for supporting field technicians and service order managers in customer relationship management solutions. Customer relationship management systems may be improved integrating location-based ser- vices in enterprise applications, including the Web environment. This integration i...

This paper describes the infrastructure needed to provide location-based services for supporting field technicians and service order managers in customer relationship management solutions. Customer relationship management systems may be improved integrating location-based services into enterprise applications, including the Web environment. This in...

In this paper a fleet tracking and monitoring system enabled to Internet is presented. For this kind of systems, it is necessary to integrate different technologies to offer the required basic functionality (wireless communication, GPS, GIS,…). These technologies enable the acquisi- tion of vehicle locations in real time and the visualization of ve...

Much geospatial data is available on the web and in off-line archives, but it is complex, heterogeneous, and incompatible. Common interfaces are the only way to enable overlays and combinations of complex and essentially different kinds of geographic information to happen automatically over the Internet. The OpenGIS Consortium (OGC) uses the term "...

RESUMEN De todas las capacidades SIG, las funcionalidades de visualización de información geográfica son las más requeridas en el desarrollo de sistemas de información que tratan con datos georeferenciados. Por su parte, las aplicaciones de seguimiento de flotas de vehículos son un ejemplo prototípico en el que, un desarrollo basado en componentes,...

The OpenGIS Consortium uses the term "Catalog" to describe the set of service interfaces supporting organization, discovery, and access of geospatial information. Catalog services help users or application software to find information that exists anywhere in a distributed computing environment. A Catalog can be thought of as a specialized database...