Proposta de migració segura d'agents amb sol·licitud de classes sota demanda per a la plataforma JADE

Aquest projecte consisteix en la implementació d'una migració d'agents mòbils amb sol·licitud de classes sota demanda de manera segura per a la plataforma JADE. En aquest projecte hem desenvolupat dos protocols de control d'accés i autentificació sobre agents i/o plataformes. Però la línia central de desenvolupament d'aquest projecte radica en la creació d'un protocol de migració sota demanda d'agents. Hem implementat dues versions d'aquest protocol. La primera versió del protocol de migració es centra en la sol·licitud de classes sota demanda i la segona versió, per tal de millorar-ne el rendiment de la primera, emmagatzema les classes que ha demanat sota demanada en una cache de la plataforma.

Simulació d'arquitectures VLIW

L'objectiu d'aquest projecte es dissenyar i implementar en Java una interfície gràfica que permeti simular l'arquitectura VLIW. Ha d'interactuar amb un simulador ja existent, VEX, i amb l'usuari. VEX permet analitzar, desenvolupar i depurar codi escrit en C sobre un processador VLIW configurable, des dels recursos hardware fíns al comportament de la "caché". L'interfície gràfica desenvolupada es diu JavaVEX. Té el gran avantatge d'evitar la introducció de les comandes de text que necesita VEX perquè son substituïdes per elements. És una eina més intuïtiva, ràpida i eficient. JavaVEX mostra informació sobre el codi C traduït a instruccions VLIW de fins a 4 operacions. També mostra els resultats de les instrucciones VLIW simulades. JavaVEX s'ha incorporat a un LiveCD. Així es pot executar l'aplicació sobre qualsevol ordinador. La finalitat docent de JavaVEX és ser utilitzada en les pràctiques de l'assignatura Arquitectura per a Computadors 2.

Projecte Argos

L'objectiu principal del projecte és el disseny d'un proxy que té com a funció filtrar el recursos web sol·licitats pels usuaris i registrar-los en un historial, indicant si s'han permès o no. Una característica important del disseny és que ha de permetre incorporar noves funcionalitats al proxy, per exemple, catxé de recursos, filtrat de correus electrònics, xats, FTP, P2P, ...). A més, com a objectiu secundari, l'autor pretén implementar el disseny en un prototipus.

Detection of matchings in a sequence of underwater images through texture analysis

This paper presents an approach to ameliorate the reliability of the correspondence points relating two consecutive images of a sequence. The images are especially difficult to handle, since they have been acquired by a camera looking at the sea floor while carried by an underwater robot. Underwater images are usually difficult to process due to light absorption, changing image radiance and lack of well-defined features. A new approach based on gray-level region matching and selective texture analysis significantly improves the matching reliability

Registro de fallos en accesos a caché (L2) del Pentium 4 mediante performance counters

Nuestro proyecto intentará conseguir la contabilización de los fallos en los accesos a caché de segundo nivel (L2) de un determinado proceso, para lo que trataremos de habilitar los contadores de rendimiento del Pentium 4, configurarlos para obtener la información buscada de acuerdo a los eventos a monitorizar y, por último, obtener esta información y dejarla adisposición de la aplicación de usuario que la requiera.

Millora de rendiment de la plataforma web Educaweb.com amb Varnish

Els objectius d'aquest projecte són la millora del rendiment de la plataforma Educaweb.com utilitzant un frontal equipat amb Varnish HTTP Cache, un programari lliure que permet emmagatzemar les pàgines a una memòria cau i evitar el seu processament repetitiu quan no és necessari.

Probabilistically analysable real-time systems (PROARTIS)

Critical real-time ebedded (CRTE) Systems require safe and tight worst-case execution time (WCET) estimations to provide required safety levels and keep costs low. However, CRTE Systems require increasing performance to satisfy performance needs of existing and new features. Such performance can be only achieved by means of more agressive hardware architectures, which are much harder to analyze from a WCET perspective. The main features considered include cache memòries and multi-core processors.Thus, althoug such features provide higher performance, corrent WCET analysis methods are unable to provide tight WCET estimations. In fact, WCET estimations become worse than for simple rand less powerful hardware. The main reason is the fact that hardware behavior is deterministic but unknown and, therefore, the worst-case behavior must be assumed most of the time, leading to large WCET estimations. The purpose of this project is developing new hardware designs together with WCET analysis tools able to provide tight and safe WCET estimations. In order to do so, those pieces of hardware whose behavior is not easily analyzable due to lack of accurate information during WCET analysis will be enhanced to produce a probabilistically analyzable behavior. Thus, even if the worst-case behavior cannot be removed, its probabilty can be bounded, and hence, a safe and tight WCET can be provided for a particular safety level in line with the safety levels of the remaining components of the system. During the first year the project we have developed molt of the evaluation infraestructure as well as the techniques hardware techniques to analyze cache memories. During the second year those techniques have been evaluated, and new purely-softwar techniques have been developed.

An efficient algorithm to perform multiple testing in epistasis screening

Background: Research in epistasis or gene-gene interaction detection for human complex traits has grown over the last few years. It has been marked by promising methodological developments, improved translation efforts of statistical epistasis to biological epistasis and attempts to integrate different omics information sources into the epistasis screening to enhance power. The quest for gene-gene interactions poses severe multiple-testing problems. In this context, the maxT algorithm is one technique to control the false-positive rate. However, the memory needed by this algorithm rises linearly with the amount of hypothesis tests. Gene-gene interaction studies will require a memory proportional to the squared number of SNPs. A genome-wide epistasis search would therefore require terabytes of memory. Hence, cache problems are likely to occur, increasing the computation time. In this work we present a new version of maxT, requiring an amount of memory independent from the number of genetic effects to be investigated. This algorithm was implemented in C++ in our epistasis screening software MBMDR-3.0.3. We evaluate the new implementation in terms of memory efficiency and speed using simulated data. The software is illustrated on real-life data for Crohn’s disease. Results: In the case of a binary (affected/unaffected) trait, the parallel workflow of MBMDR-3.0.3 analyzes all gene-gene interactions with a dataset of 100,000 SNPs typed on 1000 individuals within 4 days and 9 hours, using 999 permutations of the trait to assess statistical significance, on a cluster composed of 10 blades, containing each four Quad-Core AMD Opteron(tm) Processor 2352 2.1 GHz. In the case of a continuous trait, a similar run takes 9 days. Our program found 14 SNP-SNP interactions with a multiple-testing corrected p-value of less than 0.05 on real-life Crohn’s disease (CD) data. Conclusions: Our software is the first implementation of the MB-MDR methodology able to solve large-scale SNP-SNP interactions problems within a few days, without using much memory, while adequately controlling the type I error rates. A new implementation to reach genome-wide epistasis screening is under construction. In the context of Crohn’s disease, MBMDR-3.0.3 could identify epistasis involving regions that are well known in the field and could be explained from a biological point of view. This demonstrates the power of our software to find relevant phenotype-genotype higher-order associations.

Imaging polarimetry of the fogbow: polarization characteristics of white rainbows measured in the high Arctic

The knowledge on the optics of fogbows is scarce, and their polarization characteristics have never been measured to our knowledge. To fill this gap we measured the polarization features of 16 fogbows during the Beringia 2005 Arctic polar research expedition by imaging polarimetry in the red, green and blue spectral ranges. We present here the first polarization patterns of the fogbow. In the patterns of the degree of linear polarization p, fogbows and their supernumerary bows are best visible in the red spectral range due to the least dilution of fogbow light by light scattered in air. In the patterns of the angle of polarization α fogbows are practically not discernible because their α-pattern is the same as that of the sky: the direction of polarization is perpendicular to the plane of scattering and is parallel to the arc of the bow, independently of the wavelength. Fogbows and their supernumeraries were best seen in the patterns of the polarized radiance. In these patterns the angular distance δ between the peaks of the primary and the first supernumerary and the angular width σ of the primary bow were determined along different radii from the center of the bow. δ ranged between 6.08° and 13.41° , while σ changed from 5.25° to 19.47° . Certain fogbows were relatively homogeneous, meaning small variations of δ and σ along their bows. Other fogbows were heterogeneous, possessing quite variable δ- and σ-values along their bows. This variability could be a consequence of the characteristics of the high Arctic with open waters within the ice shield resulting in the spatiotemporal change of the droplet size within the fog