Constructive updating/downdating of oblique projectors: a generalization of the Gram-Schmidt process

A generalization of the Gram-Schmidt procedure is achieved by providing equations for updating and downdating oblique projectors. The work is motivated by the problem of adaptive signal representation outside the orthogonal basis setting. The proposed techniques are shown to be relevant to the problem of discriminating signals produced by different phenomena when the order of the signal model needs to be adjusted.Comment: As it will appear in Journal of Physics A: Mathematical and Theoretical (2007

Measurements design and phenomena discrimination

The construction of measurements suitable for discriminating signal components produced by phenomena of different types is considered. The required measurements should be capable of cancelling out those signal components which are to be ignored when focusing on a phenomenon of interest. Under the hypothesis that the subspaces hosting the signal components produced by each phenomenon are complementary, their discrimination is accomplished by measurements giving rise to the appropriate oblique projector operator. The subspace onto which the operator should project is selected by nonlinear techniques in line with adaptive pursuit strategies

On the truncation of the harmonic oscillator wavepacket

We present an interesting result regarding the implication of truncating the wavepacket of the harmonic oscillator. We show that disregarding the non-significant tails of a function which is the superposition of eigenfunctions of the harmonic oscillator has a remarkable consequence: namely, there exist infinitely many different superpositions giving rise to the same function on the interval. Uniqueness, in the case of a wavepacket, is restored by a postulate of quantum mechanics

Vitamina C : una estrategia didáctica polifuncional

El presente trabajo tiene como objetivo contextualizar contenidos curriculares de química: incursionando en el área de bioquímica, como elementos básicos de la formación en química del estudiante; proporcionando información general sobre las propiedades de la vitamina C que permitan al estudiante, como ciudadano, tener libertad de elección frente a la vasta publicidad que se ofrece, entre otros, en los medios masivos de comunicación; aplicando su cultura científica a situaciones de la vida cotidiana y, por lo tanto, valorando la importancia de la educación científica para poder ser capaz de conocer mejor lo que consume y poder opinar en forma crítica sobre ello. Se presentan técnicas sencillas para investigar la presencia de vitamina C en alimentos de uso común. Se discuten distintas estrategias de presentación y tratamiento del tema en los distintos niveles escolares con objetivos diferentes y se analizan cambios en la metodología de trabajo en el aula. Este trabajo fue presentado bajo la modalidad de taller en el XV Congreso Nacional e Internacional de Profesores de Química y los resultados y conclusiones a las que se arribaron fueron ampliamente satisfactorias, ya que permitieron una revalorización de la tarea educativa buscando un currículo más abierto donde el estudiante se sienta partícipe de su proceso de aprendizaje y encuentre contenidos científicos útiles para su vida.This paper attempts to contextualise chemistry curricula contents, entering the field of biochemistry, as basic elements for the formation of chemistry in the student by providing general information on the properties of C vitamin that allows the student, as a citizen, the freedom to choose in front of the huge publicity offered to them, among others, by the mass media. They can apply their scientific culture to everyday life, thus assessing how important scientific education is to be able to better know what is consumed and give a critical opinion. We present simple techniques to find C vitamin in commonly used food. We discuss different strategies to present and deal with this subject at different school levels with different aims, and we analyse the changes in the classroom working methodology. This paper was presented as a workshop in the 15th National and International Congress of Chemistry Professors and its results and conclusion were highly satisfactory, as they allowed revaluing the educational task aiming at a more open curriculum where the student feels part of his learning process and finds scientific contents useful in his everyday life

Metodología para seleccionar tecnologías Web 2.0 para la docencia

Actualmente existe un gran auge en el uso y difusión de las herramientas Web 2.0 tanto en el contexto profesional como en el personal. Su aplicación al ámbito de la docencia, tal y como sugieren algunos estudios, puede tener numerosas ventajas. Sin embargo, el abanico de herramientas Web 2.0 es muy amplio y por tanto sería de utilidad disponer de una metodología que pudiera guiar al docente a la hora de elegir la tecnología más adecuada a su proceso de enseñanza-aprendizaje según los objetivos perseguidos, así como en su implantación y posterior evaluación de los resultados alcanzados. En este artículo, se presenta una metodología de ayuda a los docentes de cualquier área de conocimiento para la selección e implantación de la tecnología Web 2.0 que más se adapte a un determinado proceso de enseñanza-aprendizaje en base a criterios docentes y técnicos. Esta metodología es el resultado de un proyecto de mejora e innovación educativa en el cual se han llevado a cabo diversas experiencias docentes sobre la aplicación de herramientas Web 2.0 en asignaturas de distintas titulaciones universitarias.SUMMARY -- The use and dissemination of Web 2.0 tools in professional and personal context is becoming more popular every day. Its application to teaching, as it is suggested by some studies, may have numerous advantages. However, the range of Web 2.0 tools is very broad and it would therefore be useful to have a methodology that guide the teacher in choosing the most appropriate technology to their teaching-learning process, taking into account some final objectives, as well as implementing and evaluating the achieved results. This paper presents a methodology to assist teachers from any area of knowledge in the selection of the Web 2.0 technology that best suits a particular teaching-learning process. This selection is based on some educational and technical criteria. The presented methodology is the result of an educational innovation and improvement project in which various teaching experiences based on the use of Web 2.0 tools have been carried out in different subjects of science degrees.Peer Reviewe

A Correlation Study between Geometry of Collared Coils and Normal Quadrupole Multipole in the Main LHC Dipoles

The quality control implemented at all LHC dipole assemblers includes precise mechanical measurements of the geometry of collared coils. A cross-analysis performed between mechanical and magnetic measurements data shows a correlation between collared coils outer dimensions and the normal quadrupole multipole (b2) for one dipole assembler. The profile geometry of the single collars - as determined from 3D measurements at the collar suppliers and CERN - could not account alone for the significant left â right aperture asymmetry observed. This triggered a deeper investigation on different elements of the geometry of single collars. The results of this work show that the relative positioning of the collaring holes, allowing a small bending deformation of collars under the effect of coil pre-stress, is an important effect that generates a b2 multipole at the limit of specification. The study has deepened the understanding of the factors affecting collared coil geometry and field quality. The precision of 3D measurements at the collar suppliers and at CERN has been improved, and a tighter quality control has been introduced at the collar suppliers

Almost Perfect Privacy for Additive Gaussian Privacy Filters

We study the maximal mutual information about a random variable $Y$ (representing non-private information) displayed through an additive Gaussian channel when guaranteeing that only $\epsilon$ bits of information is leaked about a random variable $X$ (representing private information) that is correlated with $Y$. Denoting this quantity by $g_\epsilon(X,Y)$, we show that for perfect privacy, i.e., $\epsilon=0$, one has $g_0(X,Y)=0$ for any pair of absolutely continuous random variables $(X,Y)$ and then derive a second-order approximation for $g_\epsilon(X,Y)$ for small $\epsilon$. This approximation is shown to be related to the strong data processing inequality for mutual information under suitable conditions on the joint distribution $P_{XY}$. Next, motivated by an operational interpretation of data privacy, we formulate the privacy-utility tradeoff in the same setup using estimation-theoretic quantities and obtain explicit bounds for this tradeoff when $\epsilon$ is sufficiently small using the approximation formula derived for $g_\epsilon(X,Y)$.Comment: 20 pages. To appear in Springer-Verla

The Certification of the Mass Concentrations of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se and Zn in Wastewater, BCR-713 (Effluent Wastewater), BCR-714 (Influent Wastewater) BCR-715 (Industrial Effluent Wastewater).

Abstract not availableJRC.D-Institute for Reference Materials and Measurements (Geel