Separation of analytic sets by rectangles of low complexity

We provide Hurewicz tests for the separation of disjoint analytic sets by rectangles of the form $\Gamma\times\Gamma'$ for $\Gamma,\Gamma'\in {\mathbf\Sigma^0_1 , \mathbf\Pi^0_1 , \mathbf\Pi^0_2 }$

Injective tests of low complexity in the plane

We study injective versions of the characterization of sets potentially in a Wadge class of Borel sets, for the first Borel and Lavrentieff classes. We also study the case of oriented graphs in terms of continuous homomorphisms, injective or not

A Matrix PRNG with S-Box Output Filtering

We describe a modification to a previously published pseudorandom number generator improving security while maintaining high performance. The proposed generator is based on the powers of a word-packed block upper triangular matrix and it is designed to be fast and easy to implement in software since it mainly involves bitwise operations between machine registers and, in our tests, it presents excellent security and statistical characteristics. The modifications include a new, key-derived s-box based nonlinear output filter and improved seeding and extraction mechanisms. This output filter can also be applied to other generators.Research partially supported by the Spanish MINECO under Project TIN2011-25452

Hacia la seguridad criptográfica en sistemas DaaS

El nuevo paradigma de computación en la nube posibilita la prestación de servicios por terceros. Entre ellos, se encuentra el de las bases de datos como servicio (DaaS) que permite externalizar la gestión y alojamiento del sistema de gestión de base de datos. Si bien esto puede resultar muy beneficioso (reducción de costes, gestión simplificada, etc.), plantea algunas dificultades respecto a la funcionalidad, el rendimiento y, en especial, la seguridad de dichos servicios. En este trabajo se describen algunas de las propuestas de seguridad en sistemas DaaS existentes y se realiza un análisis de sus características principales, introduciendo un nuevo enfoque basado en tecnologías no exclusivamente relacionales (NoSQL) que presenta ventajas respecto a la escalabilidad y el rendimiento.Investigación parcialmente financiada por el MINECO mediante el proyecto TIN2011-25452

IMM-Based lane-change prediction in highways with low-cost GPS/INS

The prediction of lane changes has been proven to be useful for collision avoidance support in road vehicles. This paper proposes an interactive multiple model (IMM)-based method for predicting lane changes in highways. The sensor unit consists of a set of low-cost Global Positioning System/inertial measurement unit (GPS/IMU) sensors and an odometry captor for collecting velocity measurements. Extended Kalman filters (EKFs) running in parallel and integrated by an IMM-based algorithm provide positioning and maneuver predictions to the user. The maneuver states Change Lane (CL) and Keep Lane (KL) are defined by two models that describe different dynamics. Different model sets have been studied to meet the needs of the IMM-based algorithm. Real trials in highway scenarios show the capability of the system to predict lane changes in straight and curved road stretches with very short latency times.Ministerio de Fomento: FOM/2454/200

Computational cost of GNG3D algorithm for mesh simplification

In this paper we present a study of the computational cost of the GNG3D algorithm for mesh optimization. This algorithm has been implemented taking as a basis a new method which is based on neural networks and consists on two differentiated phases: an optimization phase and a reconstruction phase. The optimization phase is developed applying an optimization algorithm based on the Growing Neural Gas model, which constitutes an unsupervised incremental clustering algorithm. The primary goal of this phase is to obtain a simplified set of vertices representing the best approximation of the original 3D object. In the reconstruction phase we use the information provided by the optimization algorithm to reconstruct the faces thus obtaining the optimized mesh. The computational cost of both phases is calculated, showing some examples

La economía de la dehesa y el desarrollo rural. La Sierra Morena sevillana

A long term strategy for development in a rural district located in Sierra Morena (Andalucía, Spain) is suggested. In this Mediterranean area, a great ecological, social and landscape diversity represents a «meeting point» among rural development politics, natural resources management and the economic activity of its population. The economic and social structure is still very traditional, where animal production (specially extensive pig production, with sheep, cattle and goats), olive growing and other forest resources such as hunting and cork industry are very important. There, large scale land ownership coexists with an important conservation area. Public policies and investment have a main influence in socio-economic dynamics of the population, who struggles among the necessary economic growth, the improvement of the quality of life and the conservation of those ecosystems that give this territory its originality and the best opportunities for the future.En el presente trabajo se sugiere una estrategia de desarrollo a largo plazo para la comarca de media montaña denominada Sierra Morena sevillana. En esta zona mediterránea, la gran diversidad ecológica, paisajística y social, supone un auténtico punto de conexión entre las políticas de desarrollo rural, la gestión de los recursos naturales y la actividad económica de sus habitantes. Se mantiene una estructura tradicional donde se combina el cultivo de secano (olivar), la ganadería extensiva o semiextensiva de cerdo ibérico con ovino, caprino y bovino, y otros aprovechamientos forestales como la caza y la transformación de corcho. La gran concentración de la propiedad de la tierra convive con la existencia de un importante espacio natural protegido bajo la figura de Parque Natural. En esta zona las políticas e inversiones públicas tienen un papel muy importante en la dinámica socioeconómica de una población que se debate entre el crecimiento económico, la mejora de la calidad de vida, y la conservación de aquellos ecosistemas que confieren al territorio su originalidad y son la base para su desarrollo económico futuro