Accurate computation of the Moore-Penrose inverse of strictly totally positive matrices

The computation of the Moore-Penrose inverse of structured strictly totally positive matrices is addressed. Since these matrices are usually very ill-conditioned, standard algorithms fail to provide accurate results. An algorithm based on the factorization and which takes advantage of the special structure and the totally positive character of these matrices is presented. The first stage of the algorithm consists of the accurate computation of the bidiagonal decomposition of the matrix. Numerical experiments illustrating the good behavior of our approach are included.Numerical experiments illustrating the good behavior of our approach are included

Accurate computations with collocation matrices of the Lupaş-type (p,q)-analogue of the Bernstein basis

A fast and accurate algorithm to compute the bidiagonal decomposition of collocation matrices of the Lupaş-type (p,q)-analogue of the Bernstein basis is presented. The error analysis of the algorithm and the perturbation theory for the bidiagonal decomposition are also included. Starting from this bidiagonal decomposition, the accurate and efficient solution of several linear algebra problems involving these matrices is addressed: linear system solving, eigenvalue and singular value computation, and computation of the inverse and the Moore-Penrose inverse. The numerical experiments carried out show the good behaviour of the algorithm.Agencia Estatal de Investigació

Least squares problems involving generalized Kronecker products and application to bivariate polynomial regression

A method for solving least squares problems (A ⊗ Bi)x = b whose coefficient matrices have generalized Kronecker product structure is presented. It is based on the exploitation of the block structure of the Moore-Penrose inverse and the reflexive minimum norm g-inverse of the coefficient matrix, and on the QR method for solving least squares problems. Firstly, the general case where A is a rectangular matrix is considered, and then the special case where A is square is analyzed. This special case is applied to the problem of bivariate polynomial regression, in which the involved matrices are structured matrices (Vandermonde or Bernstein-Vandermonde matrices). In this context, the advantage of using the Bernstein basis instead of the monomial basis is shown. Numerical experiments illustrating the good behavior of the proposed algorithm are included.Ministerio de Economía y Competitivida

Error analysis, perturbation theory and applications of the bidiagonal decomposition of rectangular totally-positive h-Bernstein-Vandermonde matrices

A fast and accurate algorithm to compute the bidiagonal decomposition of rectangular totally positive h-Bernstein-Vandermonde matrices is presented. The error analysis of the algorithm and the perturbation theory for the bidiagonal decomposition of totally positive h-Bernstein-Vandermonde matrices are addressed. The computation of this bidiagonal decomposition is used as the first step for the accurate and efficient computation of the singular values of rectangular totally positive h-Bernstein-Vandermonde matrices and for solving least squares problems whose coefficient matrices are such matrices.Agencia Estatal de Investigació

Las energías renovables y el crecimiento sostenible para la sociedad

Este proyecto es fruto de la colaboración entre las Facultades de Ciencias de la Información y de Ciencias Químicas de la Universidad Complutense de Madrid. El objetivo es desarrollar una estrategia sinérgica y transversal para informar de los conocimientos científicos. La tendencia que muestra el consumo de las TIC y de los canales audiovisuales por parte de la población adolescente y por los estudiantes que acceden a la universidad indica que deben reorientarse las políticas de comunicación. Cualquier otro enfoque quedará obsoleto antes de ser aplicado. El plan está enfocado a elaborar una campaña de comunicación, articulada alrededor de las energías renovables como garantía de un futuro sostenible para la comunidad universitaria complutense. Actualmente existe un déficit en el conocimiento pragmático de lo que supone el uso de fuentes de energía que no respeten el medio ambiente. Consideramos que supone una mejora de la calidad docente la aportación de herramientas de conocimiento adaptadas a las nuevas tecnologías de la información que ya son de uso cotidiano. La innovación y la investigación deben adaptarse a los nuevos lenguajes comunicativos y por este motivo el plan de comunicación - objeto de este proyecto - contempla el uso de una aplicación (“APP”) creada exprofeso, contenidos adecuados a la red social “Instagram” y la edición de una serie de espacios audiovisuales a difundir a través un canal creado en la plataforma “YouTube”

IVAN: Intelligent van for the distribution of pharmaceutical drugs

This paper describes a telematic system based on an intelligent van which is capable of tracing pharmaceutical drugs over delivery routes from a warehouse to pharmacies, without altering carriers' daily conventional tasks. The intelligent van understands its environment, taking into account its location, the assets and the predefined delivery route; with the capability of reporting incidences to carriers in case of failure according to the established distribution plan. It is a non-intrusive solution which represents a successful experience of using smart environments and an optimized Radio Frequency Identification (RFID) embedded system in a viable way to resolve a real industrial need in the pharmaceutical industry. The combination of deterministic modeling of the indoor vehicle, the implementation of an ad-hoc radiating element and an agile software platform within an overall system architecture leads to a competitive, flexible and scalable solution.This work has been funded by the Ministry of Science and Innovation of Spain under INNPACTO funding program (RailTrace project, IPT-370000-2010-036)

Prevalence of dementia and major dementia subtypes in Spanish populations: A reanalysis of dementia prevalence surveys, 1990-2008

Background This study describes the prevalence of dementia and major dementia subtypes in Spanish elderly. Methods We identified screening surveys, both published and unpublished, in Spanish populations, which fulfilled specific quality criteria and targeted prevalence of dementia in populations aged 70 years and above. Surveys covering 13 geographically different populations were selected (prevalence period: 1990-2008). Authors of original surveys provided methodological details of their studies through a systematic questionnaire and also raw age-specific data. Prevalence data were compared using direct adjustment and logistic regression. Results The reanalyzed study population (aged 70 year and above) was composed of Central and North-Eastern Spanish sub-populations obtained from 9 surveys and totaled 12,232 persons and 1,194 cases of dementia (707 of Alzheimer's disease, 238 of vascular dementia). Results showed high variation in age- and sex-specific prevalence across studies. The reanalyzed prevalence of dementia was significantly higher in women; increased with age, particularly for Alzheimer's disease; and displayed a significant geographical variation among men. Prevalence was lowest in surveys reporting participation below 85%, studies referred to urban-mixed populations and populations diagnosed by psychiatrists. Conclusion Prevalence of dementia and Alzheimer's disease in Central and North-Eastern Spain is higher in females, increases with age, and displays considerable geographic variation that may be method-related. People suffering from dementia and Alzheimer's disease in Spain may approach 600,000 and 400,000 respectively. However, existing studies may not be completely appropriate to infer prevalence of dementia and its subtypes in Spain until surveys in Southern Spain are conductedFinancial aid was obtained from the Spanish RECSP C03-09, CIEN C03-06 and CIBERNED networks, and from the Pfizer Foundation in particularS

Colorectal adenomas contain multiple somatic mutations that do not coincide with synchronous adenocarcinoma specimens

We have performed a comparative ultrasequencing study of multiple colorectal lesions obtained simultaneously from four patients. Our data show that benign lesions (adenomatous or hyperplastic polyps) contain a high mutational load. Additionally multiple synchronous colorectal lesions show non overlapping mutational signatures highlighting the degree of heterogeneity between multiple specimens in the same patient. Observations in these cases imply that considering not only the number of mutations but an effective oncogenic combination of mutations can determine the malignant progression of colorectal lesions