Higinio Ramos Calle

Topics of contemporary computational mathematics

It is our great pleasure to introduce this Special Issue of the International Journal of Computer Mathematics containing an exciting collection of computational and applied mathematics papers presented at the 10th International Conference of Computational and Mathematical Methods in Science and Engineering (CMMSE-2010), held in Almería (Spain) between 26 and 30 June 2010. This Special Issue continues a well-consolidated tradition of producing special issues for the CMMSE that dates back to 2002. The multi-disciplinary International Conference of Computational and Mathematical Methods in Science and Engineering embraces all the computational science and engineering fields. Since its inception in 2000, the novel mathematical and computational methods and applications for a wide range of disciplines – including physics, chemistry, engineering and economics – have been presented, widely discussed and disseminated within the research community. The CMMSE, which aspires to continue acting as a stimulating point of contact between different disciplines, ultimately aims to encourage new mathematical and computational insights to underpin the progress demanded by our society. The first article of this Special Issue, Multi-authority attribute-based encryption with honestbut-curious central authority, by Božović et al. [2], considers multi-authority attribute-based encryption that is capable of handling disjoint sets of attributes distributed among many authorities. Its threshold scheme based on encryption offers the same security guarantees as Chase’s proposal with the added advantage that it tolerates an honest-but-curious central authority. By assuming that the central authority is honest in the initialization phase, the indistinguishability of the encryption is guaranteed. This proposal improves on Chase’s construction by imposing a weaker assumption on the central authority without paying a high cost in terms of efficiency. The second article, Complete partial metric spaces have partially metrizable computational models, by Romaguera et al. [12], generalizes the Edalat and Heckmann construction for metric spaces by considering a complete partial metric in the domain of formal balls in a complete metric space (X, p) that extends p and induces the Scott topology. It thus introduces the notion of a partially metrizable computational model that characterizes topological spaces by admitting a compatible complete partial metric. The article by Criado et al. [4], motivated by real-life situations in social and communications networks, presents complex systems with some meso-scale structures. The clustering and the metric structures of the multilevel network described and analysed are the analytical relationships

Improving Mathematical Competencies of Students Accessing to Higher Education from Vocational Training Modules

This article describes the behavior and results obtained by two groups of engineering students from Vocational Training Modules who were recruited to use an on-line tool designed to improve their mathematical performance. Its effectiveness is evaluated using examinations results and an anonymous satisfaction questionnaire. The main difference between both groups is the presence or absence of deadlines for the recommended tasks. The results show that these initiatives are very welcome, and are also effective and capable of improving basic mathematical skills. The pattern of use shows strong persistence along the time, a significant use during non-working hours and a good correspondence between course participation and good performance in the final examinations. However, results, especially self-confidence and dropout rate, depend strongly on assigning due dates for doing the tasks. The use of deadlines arises as an important factor contributing to success.

Materials for a course in Calculus on several variables: An example of inter-university collaboration

Universities today offer many courses where the study materials can be obtained online through different mechanisms. The terms e-learning and b-learning are being overshadowed by u-learning (ubiquitous learning), since the learning scenario is any place and any device that can be used to get the materials. The task of preparing the appropriate materials in this new context cannot be addressed individually and, consequently, international collaborative process can be very fruitful. The main goal is to adapt the study materials for using in several Universities, with official recognition for any University involved in the collaborative process and with agreements with other Universities interested in the use of such materials. We will present an ongoing experience which involves the National Technological University (UTN) in Buenos Aires, Argentina, and Spanish universities: Salamanca University (USAL) and Pontificia Comillas University (UPCOMILLAS) in Madrid. The authors of this paper have updated a virtual Multivariable Calculus course, hosted in the virtual learning environment STUDIUM to be used by the students from the three universities.