Santi Caballé

A Review on Massive E-Learning (MOOC) Design, Delivery and Assessment

MOOCs or Massive Online Open Courses based on Open Educational Resources (OER) might be one of the most versatile ways to offer access to quality education, especially for those residing in far or disadvantaged areas. This article analyzes the state of the art on MOOCs, exploring open research questions and setting interesting topics and goals for further research. Finally, it proposes a framework that includes the use of software agents with the aim to improve and personalize management, delivery, efficiency and evaluation of massive online courses on an individual level basis.

The SR-GCWS hybrid algorithm for solving the capacitated vehicle routing problem

The capacitated vehicle routing problem (CVRP) is a well known problem which has long been tackled by researchers for several decades now, not only because of its potential applications but also due to the fact that CVRP can be used to test the efficiency of new algorithms and optimization methods. The objective of our work is to present SR-GCWS, a hybrid algorithm that combines a CVRP classical heuristic with Monte Carlo simulation using state-of-the-art random number generators. The resulting algorithm is tested against some well-known benchmarks. In most cases, our approach is able to compete or even outperform much more complex algorithms, which is especially interesting if we consider that our algorithm does not require any previous parameter fine-tuning or set-up process. Moreover, our algorithm has been able to produce high-quality solutions almost in real-time for most tested instances. Another important feature of the algorithm worth mentioning is that it uses a randomized constructive heuristic, capable of generating hundreds or even thousands of alternative solutions with different properties. These alternative solutions, in turn, can be really useful for decision-makers in order to satisfy their utility functions, which are usually unknown by the modeler. The presented methodology may be a fine framework for the development of similar algorithms for other complex combinatorial problems in the routing arena as well as in some other research fields.

Improvement of JXTA protocols for supporting reliable distributed applications in P2P systems

In any distributed application, the communication between the distributed processes/nodes of the distributed systems is essential for both reliability and efficiency matters. In this work we address this issue for distributed applications based on JXTA protocols. After a careful examination of the current version of JXTA protocols, we observed the need for improving the original JXTA protocols, such as pipe services, to ensure reliable communication between peer nodes and the discovery and presence service to increase the performance of the applications. The re-implemented protocols have been validated in practice by deploying a P2P network using nodes of PlanetLab platform and testing each of the extended protocols using this real P2P network.

An Integrated System for Wireless Cellular and Ad-Hoc Networks Using Fuzzy Logic

Several solutions have been proposed for improving the Quality of Service (QoS) in wireless cellular networks, such as Call Admission Control (CAC) and handover strategies. However, none of them considers the usage of different interfaces for different conditions. In this work, we propose the Fuzzy-Based Multi-Interface System (FBMIS), where each node is equipped with two interfaces: the traditional cellular network interface and Mobile Ad hoc Networks (MANET) interface. The proposed FBMIS system is able to switch from cellular to Ad-Hoc mode and vice versa. We consider three input parameters: distance between nodes, node mobility and the angle between node and the base station. We evaluated the performance of the proposed system by computer simulations using MATLAB. The simulation results show that our system has a good performance.

Using mobile devices to support online collaborative learning

Mobile collaborative learning is considered the next step of on-line collaborative learning by incorporating mobility as a key and breakthrough requirement. Indeed, the current wide spread of mobile devices and wireless technologies brings an enormous potential to e-learning, in terms of ubiquity, pervasiveness, personalization, flexibility, and so on. For this reason, Mobile Computer-Supported Collaborative Learning has recently grown from a minor research field to significant research projects covering a fairly variety of formal and specially informal learning settings, from schools and universities to workplaces, museums, cities and rural areas. Much of this research has shown how mobile technology can offer new opportunities for groups of learners to collaborate inside and beyond the traditional instructor-oriented educational paradigm. However, mobile technologies, when specifically applied to collaborative learning activities, are still in its infancy and many challenges arise. In addition, current research in this domain points to highly specialized study cases, uses, and experiences in specific educational settings and thus the issues addressed in the literature are found dispersed and disconnected from each other. To this end, this paper attempts to bridge relevant aspects of mobile technologies in support for collaborative learning and provides a tighter view by means of a multidimensional approach.

Providing effective feedback, monitoring and evaluation to on-line collaborative learning discussions

Learning and knowledge building have become critical competences for people in the knowledge society era. In this paper, we propose a sociolinguistic dialogue model for understanding how learning evolves and how cognitive process is constructed in on-line discussions. The knowledge extracted from this model is used to assess participation behavior, knowledge building and performance. The ultimate purpose is to provide effective feedback, evaluation and monitoring to the discussion process. Seven hundred students from the Open University of Catalonia in Spain participated in this study. Results showed that learning and knowledge building may be greatly enhanced by presenting selected knowledge to learners as for their particular skills exhibited during interaction. In addition, this valuable provision of information is used as a meta cognitive tool for tutors and moderators for monitoring and evaluating the discussion process more conveniently. This contribution presents our conceptual model for interaction management as well as key design guidelines and evaluation results. Implications of this study are remarked and further research directions are proposed.

FBMIS: A Fuzzy-Based Multi-interface System for Cellular and Ad Hoc Networks

Several solutions have been proposed for improving the Quality of Service (QoS) in wireless cellular networks, such as Call Admission Control (CAC) and handover strategies. However, none of them considers the usage of different interfaces for different conditions. In this work, apart from using only Base Stations (BSs) as an important device of cellular networks, we propose a multi-interface approach in order to avoid BS overloads and improve the QoS of wireless communications. We propose a system, where each node is equipped with two interfaces: the traditional cellular network interface and Mobile Ad hoc Networks (MANET) interface. The main difficulty for this system is how to choose the right interface in order to guarantee a minimal usage of network resources and at the same time keeping the communication performance in a satisfactory level. For this purpose, in this paper we propose a Fuzzy-Based Multi-Interface System (FBMIS), where each node is able to switch from cellular to Ad hoc and vice versa. We consider three input parameters and one output parameter. From the simulation results, our system shows a good performance.

Distributed-based massive processing of activity logs for efficient user modeling in a Virtual Campus

This paper reports on a multi-fold approach for the building of user models based on the identification of navigation patterns in a virtual campus, allowing for adapting the campus’ usability to the actual learners’ needs, thus resulting in a great stimulation of the learning experience. However, user modeling in this context implies a constant processing and analysis of user interaction data during long-term learning activities, which produces huge amounts of valuable data stored typically in server log files. Due to the large or very large size of log files generated daily, the massive processing is a foremost step in extracting useful information. To this end, this work studies, first, the viability of processing large log data files of a real Virtual Campus using different distributed infrastructures. More precisely, we study the time performance of massive processing of daily log files implemented following the master-slave paradigm and evaluated using Cluster Computing and PlanetLab platforms. The study reveals the complexity and challenges of massive processing in the big data era, such as the need to carefully tune the log file processing in terms of chunk log data size to be processed at slave nodes as well as the bottleneck in processing in truly geographically distributed infrastructures due to the overhead caused by the communication time among the master and slave nodes. Then, an application of the massive processing approach resulting in log data processed and stored in a well-structured format is presented. We show how to extract knowledge from the log data analysis by using the WEKA framework for data mining purposes showing its usefulness to effectively build user models in terms of identifying interesting navigation patters of on-line learners. The study is motivated and conducted in the context of the actual data logs of the Virtual Campus of the Open University of Catalonia.

A parallel grid-based implementation for real-time processing of event log data of collaborative applications

Collaborative applications usually register user interaction in the form of semi-structured plain text event log data. Extracting and structuring of data is a prerequisite for later key processes such as the analysis of interactions, assessment of group activity, or the provision of awareness and feedback. Yet, in real situations of online collaborative activity, the processing of log data is usually done offline since structuring event log data is, in general, a computationally costly process and the amount of log data tends to be very large. Techniques to speed and scale up the structuring and processing of log data with minimal impact on the performance of the collaborative application are thus desirable to be able to process log data in real time. In this paper, we present a parallel grid-based implementation for processing in real time the event log data generated in collaborative applications. Our results show the feasibility of using grid middleware to speed and scale up the process of structuring and processing semi-structured event log data. The Grid prototype follows the Master Worker (MW) paradigm. It is implemented using the Globus Toolkit (GT) and is tested on the Planetlab platform.

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.