Simonetta Pallottelli

Distributed and collaborative learning objects repositories on grid networks

The paper deals with the design and a prototype implementation of a collaborative repository of scientific learning objects based on an efficient mechanism of filing and retrieving distributed knowledge on the Grid. The proposed repository can deal with a large variety of different learning contents. Its prototype implementation, developed for Chemistry contents, is part of an extended architecture consisting of a federation of autonomous local repositories. The federation is led by a coordinator who keeps track of the repository in which the learning objects are directly stored or referenced. In each repository server, a locally hosted Web Portal allows a easy management of the repository through a CMS front-end.

Federation of distributed and collaborative repositories and its application on science learning objects

The paper deals with the design and the implementation of a federation of collaborative repositories for learning objects management based on an efficient mechanism of filing and retrieving distributed knowledge. The proposed federation is meant to deal with a large variety of different contents though the discussed prototype implementation is concerned with scientific and educational subjects in particular. The existing hierarchic architecture has been modified into a peer network model. Both the pure peer network and the hybrid topologies are tested to evaluate their scalability with both geographical extension and volume of contents. Additional elements of evaluation have been the capability of enhancing collaboration and fault tolerance.

Taxonomy management in a federation of distributed repositories: a chemistry use case

The increasingly popular Learning Object-based didactic approach has been investigated by considering related activities of the European Chemistry Thematic Network. Learning Objects specific interoperability and reusability properties have been considered for building a didactic-scientific repositories federation. For this reason international standards have been adopted to solve interoperability problems among the different computing elements of the adopted platforms and a module has been created to effectively manage taxonomy to classify Learning Objects via ontology-based criteria.

Multi-path traces in semantic graphs for latent knowledge elicitation

In this work an online collaborative semantic network is explored. The method used is based on multi-path traces for extracting latent contextual knowledge, which explores an unknown Semantic proximity measures based on search engines are uses as heuristics to navigate the collaborative network, in order to find multiple random paths representing traces between seed concepts. The exploration is driven by an online randomized walk informed by those heuristics, where the multiple traces model reinforces the most relevant explanatory paths using a pheromone-like approach to elicit latent contexts. Experiments have been held on Wikipedia and on the Word Similarity 353 dataset to evaluate the effectiveness of the method. The general methodology can be easily extended to other online collaborative graphs and to non-textual domains.

An efficient taxonomy assistant for a federation of science distributed repositories: a chemistry use case

The paper describes the design and the implementation of a built-in assistant software module aimed at managing the metadata of a federation of collaborative repositories of learning objects. The paper focuses mainly on the standardization of the classification criteria and their application to Molecular sciences.

Learning Objects Efficient Handling in a Federation of Science Distributed Repositories

The dynamic sharing of learning materials among the members of a Virtual Education Community aimed at implementing a collaborative mechanism of producing, testing and improving learning objects is discussed. The resulting assemblage of an efficient distributed repositories platform offered us the opportunity of testing different search engines. The adopted solutions were found to offer an effective support to the sharing of learning objects. As a use case a Learning object dealing with the slides of lectures on the dynamics of two body collisions shared between the University of Perugia and Genoa is discussed.

Context-based image semantic similarity

In this work we propose Context-based Image Similarity, a scheme for discovering and evaluating image similarity in terms of the associated groups of concepts. Several semantic proximity/similarity among image concepts and different concept ontology - WordNet Distance, Wikipedia Distance, Flickr Distance, Confidence, Normalized Google Distance (NGD), Pointwise Mutual Information (PMI) and PMING, have been considered as elementary metrics for the context. Comparing to Content Based Image Retrieval (CBIR), which measures the image content similarities by low level features, the proposed Context-based Image Similarity outperformed CBIR in measuring the deep concept similarity and relationship of images. Experimental results, obtained in the domain of images semantic similarity using search engine based tag similarity, show the adequacy of the proposed approach in order to reflect the collective notion of semantic similarity.

E-studium: blended e-learning for university education support

In the changing framework of education and training, the e-studium project proposes a dynamic and versatile education system, effectively managing the learning process and using Information and Communication Technologies (ICTs) to respond to the specific characteristics of a variety of different degree programmes and courses and, at the same time, to the individual needs of a wide audience of students disseminated throughout Italy. The organisation model adopted in e-studium is an integrated multiple instances e-learning system. At the kernel of e-studium is MetaLearn, a software integration component which connects the different information and authentication sources, such as the academic registrar (information about students) and faculties databases (data on lecturers and programmes) with the target multiple e-learning platforms. In the experiment the MetaLearn architecture has been implemented on top of a set of target Moodle Course Management System (CMS) instances, thus realising the blended e-learning approach. In this work the main architectural features of MetaLearn and the different phases of development and implementation of the e-studium project are presented. The results also include usage analysis and a discussion on the impact of the quality of teaching on students, and on the requirements posed on the academic members who participated in the project.

Mobile Device Access to Collaborative Distributed Repositories of Chemistry Learning Objects

The educational open contents are having a very strong impact in research and training activities. In this paper we discuss the use of Internet to supply educational contents in open and free formats from distributed repositories containing educational and scientific resources. Starting from an existing federation of distributed repositories (G-Lorep) [1] and working on parameters defined by apps, we extended their functionalities to allow mobile devices access. The structure of the access, search, selection, download, use/reuse functions needed to manage learning objects on distributed repositories have also been revisited for adaptation to mobile use.

Exchange of Learning Objects Between a Learning Management System and a Federation of Science Distributed Repositories

The paper illustrates G-Lorep, a tool devoted both to dynamic sharing of learning materials among the members of a Virtual Education Community and to the implementing of a collaborative mechanism of increasing and improving learning objects. The purpose of integrating a federation of distributed repositories with an Learning Management System (LMS), allowing the sharing of information among different platforms, is to provide the capability of uploading/ downloading files on/from a common server where the LMS is installed and made available to a federated repository. As a use case the activities related to a set of chemistry learning objects generated on the LMS platform of a federated Content Management System (CMS) by the University of Genoa and used by other European Universities are considered.