Joan Manuel Marquès

Towards a generic platform for developing CSCL applications using Grid infrastructure

The goal of this paper is to explore the possibility of using CSCL component-based software under a Grid infrastructure. The merge of these technologies represents an attractive, but probably quite laborious enterprise if we consider not only the benefits but also the barriers that we have to overcome. This work presents an attempt toward this direction by developing a generic platform of CSCL components and discussing the advantages that we could obtain if we adapted it to the Grid. We then propose a means that could make this adjustment possible due to the high degree of genericity that our library component is endowed with by being based on the generic programming paradigm. Finally, an application of our library is proposed both for validating the adequacy of the platform which it is based on and for indicating the possibilities gained by using it under the Grid.

REMOTE, a Wireless Sensor Network Based System to Monitor Rowing Performance

In this paper, we take a hard look at the performance of REMOTE, a sensor network based application that provides a detailed picture of a boat movement, individual rower performance, or his/her performance compared with other crew members. The application analyzes data gathered with a WSN strategically deployed over a boat to obtain information on the boat and oar movements. Functionalities of REMOTE are compared to those of RowX [1] outdoor instrument, a commercial wired sensor instrument designed for similar purposes. This study demonstrates that with smart geometrical configuration of the sensors, rotation and translation of the oars and boat can be obtained. Three different tests are performed: laboratory calibration allows us to become familiar with the accelerometer readings and validate the theory, ergometer tests which help us to set the acquisition parameters, and on boat tests shows the application potential of this technologies in sports.

LaCOLLA: Middleware for Self-Sufficient Online Collaboration

The LaCOLLA middleware makes it possible for collaborators to interact using their own resources without depending on centralized regimes. By contributing their own resources, group members can organize and communicate using a federated peer-to-peer model. This lets the group function regardless of whether a member removes resources and despite network or node failures or disconnection. In turn, this capacity for self-organization, together with location transparency, lets application developers create self-sufficient applications for collaborative activity

Supporting the composition of effective virtual groups for collaborative learning

In this paper, the authors explore the different processes involved in constructing effective virtual collaborative learning groups, especially why, when and how these processes affect group formation and to which degree they guarantee the creation of well-functioning and successful learning groups. A student can benefit from collaborative learning only if he/she participates in supportive learning teams. For this reason, their research interest is to aid and provide the means for the configuration of learning groups that are appropriate for different learning situations. A key issue in this process is to make the educational function and structure of collaborative learning groups clear, by identifying and making explicit both the individual and group learning and social goals, as well as the relationships, interaction processes and roles that determine the nature and idiosyncrasy of the group.

Design of a Motion Detector to Monitor Rowing Performance Based on Wireless Sensor Networks

Wireless Sensor Networks (WSN) have been applied to gather data from a large number of scenarios. WSN provide the potential to collect data at spatial and temporal scales that are many times not feasible with past instrumentation. Although many applications have been already developed, little has been done using WSN as infrastructure for sports oriented commercial applications.This paper studies the use of WSN to develop motion detectors. Particularly REMOTE, a sensor network based application that provides a detailed picture of a boat movement, rower’s individual performance, or his/her performance compared to other crew members is proposed. The application aims to analyze data gathered with a WSN strategically deployed over a boat to obtain information on the boat and oar movements. The paper presents the architecture, software design and hardware infrastructure used to develop the application.

Solving the deterministic and stochastic uncapacitated facility location problem: from a heuristic to a simheuristic

Abstract The uncapacitated facility location problem (UFLP) is a popular combinatorial optimization problem with practical applications in different areas, from logistics to telecommunication networks. While most of the existing work in the literature focuses on minimizing total cost for the deterministic version of the problem, some degree of uncertainty (e.g., in the customers’ demands or in the service costs) should be expected in real-life applications. Accordingly, this paper proposes a simheuristic algorithm for solving the stochastic UFLP (SUFLP), where optimization goals other than the minimum expected cost can be considered. The development of this simheuristic is structured in three stages: (i) first, an extremely fast savings-based heuristic is introduced; (ii) next, the heuristic is integrated into a metaheuristic framework, and the resulting algorithm is tested against the optimal values for the UFLP; and (iii) finally, the algorithm is extended by integrating it with simulation techniques, and the resulting simheuristic is employed to solve the SUFLP. Some numerical experiments contribute to illustrate the potential uses of each of these solving methods, depending on the version of the problem (deterministic or stochastic) as well as on whether or not a real-time solution is required.

A Methodological Framework for Project-based Collaborative Learning in a Networked Environment

In this work we present a new way to use existing technology in a real learning context. We investigate and propose a scenario based on collaborative work of virtual groups of students developing a software project. Our intent is to promote learning through collaborative implementation of a project in shared workspaces. This raises several important issues that concern virtual group formation techniques, group regulation and role-playing by students. Other important aspects are related to the pedagogical side and include setting project development phases, assessment, tutor role, student tracking, and the tutors understanding and awareness of the social and cognitive processes. We consider them to be fundamental concerns and influencing factors in supervising, guiding and enhancing the collaborative learning process. Our approach describes the bases of a methodological framework for collaborative project development and proposes some solutions to the above matters. It also allows for the exploration of new forms of collaborative learning and teaching.

WWG: a wide-area infrastructure to support groups

Group learning at Internet scale is becoming more frequent in university courses. This complex process requires support by distributed computing learning support infrastructures.This paper describes the design of WWG (World-Wide Groups): a distributed and decentralized infrastructure with the aim of supporting distributed group learning and team work, centered on the distribution of events, so that every participant can be notified and thus be aware of the actions, changes, progress of the groups he belongs to.The design issues, requirements and the resulting architecture are presented. WWG is based on a multi-component architecture where metainformation agents are responsible for helping the events to reach the members of the group; the repository agents are responsible for the storage of group information; and user agents are responsible for the representation of users (sources and sinks of events). In this paper we tried to show that, applying events transformation policies, WWG is scalable at group level.

A simulation-optimization approach to deploy Internet services in large-scale systems with user-provided resources

Cloud computing systems can benefit from the use of personal and non-dedicated computers, which are currently employed in volunteer computing systems. Being non-dedicated, these resources show random behavior regarding the times they are online (available) and offline. Accordingly, their availability levels are lower than those of traditionally employed dedicated resources. Thus, in order to use non-dedicated resources in cloud computing environments, it is necessary first to solve the problem of how to attain high availability levels for the Internet services deployed over them. Most approaches on how to guarantee high service availability levels with non-dedicated resources are based on the introduction of high degrees of redundancy into the system. However, this praxis leads to an inefficient usage of computational resources and, therefore, to higher operational costs. Accordingly, the focus of this paper is the problem of minimizing the cost of a service deployment over non-dedicated resources while providing a high level of service availability. In order to solve this stochastic optimization problem, the paper proposes a hybrid algorithm that combines a metaheuristic component with a discrete-event simulation component. The metaheuristic component is used to search for an efficient configuration of resources. The simulation component is integrated inside the metaheuristic and used to estimate the service availability of each promising configuration. A numerical experiment section, comparing the performance of several algorithms, contributes to validating the proposed approach as well as to illustrate its potential applications.

Towards an open grid marketplace framework for resources trade

A challenge of Grid computing is to provide automated support for the creation and exploitation of virtual organisations (VOs), involving individuals and different autonomous organizations, to which resources are pooled from potentially diverse origins. In the context of the presented work, virtual organizations trade grid resources and services according to economic models in electronic marketplaces. Thus in this paper we propose GRIMP (Grid Marketplace), a generic framework that provides services to support spontaneous creation of grid resources markets on demand. We motivate the need for such framework, present our design approach as well as the implementation and execution models.