A system to communicate hidden information using color images

The objective of this paper is to present a system to communicate hidden information among different users by means of images. The tasks that the system is able to carry on can be divided in two different groups of utilities, implemented in java. The first group of utilities are related with the possibility to hide information in color images, using a steganographic function based on the least significant bit (LSB) methods. The second group of utilities allows us to communicate with other users with the aim to send or receive images, where some information have been previously embedded. Thus, this is the most significant characteristic of the implementation, we have built an environment where we join the email capabilities to send and receive text and images as attached files, with the main objective of hiding information.

El portafolio discente en línea como herramienta de aprendizaje transversal

El desarrollo de competencias transversales proporciona al alumno una formación integral. Sin embargo, la puesta en práctica de la transversalidad entre asignaturas no es una tarea trivial y plantea varios inconvenientes que deben resueltos de una manera óptima para aprovechar las sinergias entre asignaturas. En nuestro caso las necesidades son: i) espacio común para la gestión de documentos, ii) disponibilidad en cualquier momento y en cualquier lugar, y iii) posibilidad de colaboración en tareas de edición de los documentos. Hemos aplicado un portafolio discente en línea que permite evaluar el resultado del aprendizaje de las asignaturas en su conjunto, y para ello hemos usado las herramientas de acceso libre que proporciona Google por su interactividad, disponibilidad y facilidad para las tareas de colaboración.

Evaluación de la Licenciatura de Ciencias del Mar en la Universidad de Alicante: una aproximación DAFO

La planificación de los programas educativos debe basarse y tener en cuenta las necesidades y tendencias de la sociedad. Para ello es necesario someter al proceso educativo a un diagnóstico y evaluación continuada, con el fin de detectar vacíos y fallos. El análisis DAFO -Debilidades-Amenazas-Fortalezas-Oportunidades- crea un marco de apoyo enfocado a identificar las necesidades de un sistema; en este caso, la sociedad educativa. Esta herramienta está diseñada para ser usado en estados preliminares de toma de decisiones o como un precursor de estrategias de planificación. En nuestro caso puede suministrar una visión general de la situación en la licenciatura de Ciencias del Mar, en base a un análisis interno por parte de los colectivos usuarios directos, además de una comprensión de los factores externos que permita conseguir una visión de futuro, con perspectivas a la hora de definir objetivos educativos, diseños programáticos o herramientas docentes eficientes. La experiencia docente obtenida durante los últimos años muestra que los alumnos, a menudo, no encuentran conexión entre los contenidos de las diferentes materias impartidas en una licenciatura y la extrapolación de los conocimientos adquiridos a situaciones reales, con una falta patente de motivación y una reducción en el rendimiento final de los alumnos en cuanto a asimilación de contenidos. Los resultados de este análisis ayudan a definir programas innovadores e integrados transversalmente, evitando contenidos redundantes e irrelevantes, y permitiendo una coherencia multidisciplinar. Con todo ello se espera mejorar el aprendizaje de contenidos transversales que permitan aprovechar los conocimientos en las materias para su aplicación posterior.

How online applications can help to achieve integral learning

The development of transversal competencies provides an integral education. However, its practical implementation among different subjects is not a trivial task. There are several issues that should be previously solved in an optimal way to take advantage of the synergy among subjects. Main issues are: i) the need for a common space for the documents management, ii) the availability of the document everywhere and anytime, and iii) the possibility to collaborate in the documents edition tasks. It was implemented a virtual portfolio for the students which allows the assessment of all the subjects in a global way. To this goal we used the Google apps due to its free access, availability and suitability for the collaborative editing tasks.

Análisis de series temporales

Análisis de series temporales. Introducción. Características generales de las series temporales. Descomposición. Predicción. Modelos ARIMA y derivados.

Creando presentaciones con Beamer

Introducción al paquete Beamer para crear nuestras primeras presentaciones.

Random exams using Sweave

The adaptation of the Spanish University to the European Higher Education Area (EEES in Spanish) demands the integration of new tools and skills that would make the teaching- learning process easier. This adaptation involves a change in the evaluation methods, which goes from a system where the student was evaluated with a final exam, to a new system where we include a continuous evaluation in which the final exam may represent at most 50% in the vast majority of the Universities. Devising a new and fair continuous evaluation system is not an easy task to do. That would mean a student’s’ learning process follow-up by the teachers, and as a consequence an additional workload on existing staff resources. Traditionally, the continuous evaluation is associated with the daily work of the student and a collection of the different marks partly or entirely based on the work they do during the academic year. Now, small groups of students and an attendance control are important aspects to take into account in order to get an adequate assessment of the students. However, most of the university degrees have groups with more than 70 students, and the attendance control is a complicated task to perform, mostly because it consumes significant amounts of staff time. Another problem found is that the attendance control would encourage not-interested students to be present at class, which might cause some troubles to their classmates. After a two year experience in the development of a continuous assessment in Statistics subjects in Social Science degrees, we think that individual and periodical tasks are the best way to assess results. These tasks or examinations must be done in classroom during regular lessons, so we need an efficient system to put together different and personal questions in order to prevent students from cheating. In this paper we provide an efficient and effective way to elaborate random examination papers by using Sweave, a tool that generates data, graphics and statistical calculus from the software R and shows results in PDF documents created by Latex. In this way, we will be able to design an exam template which could be compiled in order to generate as many PDF documents as it is required, and at the same time, solutions are provided to easily correct them.

Is Maths everywhere? Our students respond

Mathematics expresses itself everywhere, in almost every facet of life - in nature all around us, and in the technologies in our hands. Mathematics is the language of science and engineering - describing our understanding of all that we observe. In fact, Galileo said that Mathematics is the language with which God has written the universe. Aristotle defined mathematics as "the science of quantity", i.e., “the science of the things that can be counted”. Now you can think that counting has a vital role in our daily life; just imagine that there were no mathematics at all, how would it be possible for us to count days, months and years? Unfortunately, people usually ignore the connection between mathematics and the daily life. Most of university degrees require mathematics. Students who choose not to take seriously mathematics or to ignore it in high school, find several difficulties when they come up against them at the university. This study explores the perceptions of how mathematics influences our daily life among our students and how teachers can use this information in order to improve the academic performance. The used research instrument was a questionnaire that was designed to identify their understanding on learning mathematics.

Quantitative stability of linear infinite inequality systems under block perturbations with applications to convex systems

The original motivation for this paper was to provide an efficient quantitative analysis of convex infinite (or semi-infinite) inequality systems whose decision variables run over general infinite-dimensional (resp. finite-dimensional) Banach spaces and that are indexed by an arbitrary fixed set J. Parameter perturbations on the right-hand side of the inequalities are required to be merely bounded, and thus the natural parameter space is l ∞(J). Our basic strategy consists of linearizing the parameterized convex system via splitting convex inequalities into linear ones by using the Fenchel–Legendre conjugate. This approach yields that arbitrary bounded right-hand side perturbations of the convex system turn on constant-by-blocks perturbations in the linearized system. Based on advanced variational analysis, we derive a precise formula for computing the exact Lipschitzian bound of the feasible solution map of block-perturbed linear systems, which involves only the system’s data, and then show that this exact bound agrees with the coderivative norm of the aforementioned mapping. In this way we extend to the convex setting the results of Cánovas et al. (SIAM J. Optim. 20, 1504–1526, 2009) developed for arbitrary perturbations with no block structure in the linear framework under the boundedness assumption on the system’s coefficients. The latter boundedness assumption is removed in this paper when the decision space is reflexive. The last section provides the aimed application to the convex case.