Adaptive MCMC methods with applications in environmental and geophysical models

This work presents new, efficient Markov chain Monte Carlo (MCMC) simulation methods for statistical analysis in various modelling applications. When using MCMC methods, the model is simulated repeatedly to explore the probability distribution describing the uncertainties in model parameters and predictions. In adaptive MCMC methods based on the Metropolis-Hastings algorithm, the proposal distribution needed by the algorithm learns from the target distribution as the simulation proceeds. Adaptive MCMC methods have been subject of intensive research lately, as they open a way for essentially easier use of the methodology. The lack of user-friendly computer programs has been a main obstacle for wider acceptance of the methods. This work provides two new adaptive MCMC methods: DRAM and AARJ. The DRAM method has been built especially to work in high dimensional and non-linear problems. The AARJ method is an extension to DRAM for model selection problems, where the mathematical formulation of the model is uncertain and we want simultaneously to fit several different models to the same observations. The methods were developed while keeping in mind the needs of modelling applications typical in environmental sciences. The development work has been pursued while working with several application projects. The applications presented in this work are: a winter time oxygen concentration model for Lake Tuusulanjärvi and adaptive control of the aerator; a nutrition model for Lake Pyhäjärvi and lake management planning; validation of the algorithms of the GOMOS ozone remote sensing instrument on board the Envisat satellite of European Space Agency and the study of the effects of aerosol model selection on the GOMOS algorithm.

Las auditorías, una metodología para planificar la preservación digital. Experiencias en España.

Se presentan los resultados obtenidos en la aplicación de diversas metodologías de auditoría para comprobar el estado de la preservación digital en distintas instituciones de España. Se concluye que las auditorías también se pueden usar como herramienta de ayuda a la planificación de sistemas de preservación digital.

Alarma per acceleració implementada sobre LPC1769 i controlada des de dispositius Android

Aquest PFC implementa el control d'una alarma activada per acceleració. S'ha realitzat sobre la placa LPC1769 i el sistema FreeRTOS. El projecte permet controlar l'alarma des de dispositius Android, a través d'un servidor intermedi que s'encarrega de la comunicació.

L’experiència del CRAI de la UB en la migració consorciada a Millennium

Aquest article pretén reflectir l'experiència viscuda a la Universitat de Barcelona (UB) en el procés viscut fa poc de canvi de sistema de Catàleg Col·lectiu de les Universitats de Catalunya (CCUC) i dels catàlegs de les institucions del Consorci de Biblioteques Universitàries de Catalunya (CBUC). Es recullen les principals actuacions i fites tècniques i organitzatives que ha assolit l'equip responsable de la implementació en les diferents fases del projecte, des d'un punt de vista professional però, sobretot, des del punt de vista personal d'implicació, de repte, de satisfacció i d'esforç. Es conclou destacant, d'una banda, la rellevància del treball en equip com a factor d'èxit en el desenvolupament d'un projecte complexi, de l'altra, la necessitat d'una reflexió global sobre els processos i fluxos de treball, per tal d'explotar al màxim les possibilitats d'un sistema de gestió integral i aconseguir el màxim d'eficiència.

Sistema de iluminación inteligente inalámbrico

Este proyecto crea un sistema de iluminación inteligente compuesto por múltiples dispositivos que, de forma inalámbrica, se sincronizan entre si, para encenderse, apagarse y cambiar el color de la luz ambiente. El sistema se ha diseñado para conectar hasta 8 dispositivos basados en el sistema embebido LPC1769 y S.O. FreeRTOS, integrando un sensor acelerómetro, varios leds de distinto color y un módulo WiFly RN-XV que los interconecta de forma inalámbrica.

Virtualització de servidors i escriptoris

Aquest treball explica com una pime passa d'un entorn de servidors majoritàriament físic a un entorn virtual aprofitant la necessitat d'actualitzar la infraestructura. La plataforma de virtualització utilitzada serà VMware tant per a servidors com per a escriptoris.

Identifying Specific Cues and Contexts Related to Smoking Craving for the Development of Effective Virtual Environments

Craving is considered the main variable associated with relapse after smoking cessation. Cue Exposure Therapy (CET) consists of controlled and repeated exposure to drug-related cues with the aim of extinguishing craving responses. Some virtual reality (VR) environments, such as virtual bars or parties, have previously shown their efficacy as tools for eliciting smoking craving. However, in order to adapt this technology to smoking cessation interventions, there is a need for more diverse environments that enhance the probability of generalization of extinction in real life. The main objective of this study was to identify frequent situations that produce smoking craving, as well as detecting specific craving cues in those contexts. Participants were 154 smokers who responded to an ad hoc self-administered inventory for assessing craving level in 12 different situations. Results showed that having a drink in a bar/pub at night, after having lunch/dinner in a restaurant and having a coffee in a cafe or after lunch/dinner at home were reported as the most craving-inducing scenarios. Some differences were found with regard to participants' gender, age, and number of cigarettes smoked per day. Females, younger people, and heavier smokers reported higher levels of craving in most situations. In general, the most widely cited specific cues across the contexts were people smoking, having a coffee, being with friends, and having finished eating. These results are discussed with a view to their consideration in the design of valid and reliable VR environments that could be used in the treatment of nicotine addicts who wish to give up smoking.

Molecular Physics of Elementary Processes relevant to Hypersonics: atom-molecule, molecule-molecule and atom-surface processes.

In the present chapter some prototype gas and gas-surface processes occurring within the hypersonic flow layer surrounding spacecrafts at planetary entry are discussed. The discussion is based on microscopic dynamical calculations of the detailed cross sections and rate coefficients performed using classical mechanics treatments for atoms, molecules and surfaces. Such treatment allows the evaluation of the efficiency of thermal processes (both at equilibrium and nonequilibrium distributions) based on state-to-state and state specific calculations properly averaged over the population of the initial states. The dependence of the efficiency of the considered processes on the initial partitioning of energy among the various degrees of freedom is discussed.

Towards personalization in digital libraries through ontologies

In this paper we describe a browsing and searching personalization system for digitallibraries based on the use of ontologies for describing the relationships between all theelements which take part in a digital library scenario of use. The main goal of thisproject is to help the users of a digital library to improve their experience of use bymeans of two complementary strategies: first, by maintaining a complete history recordof his or her browsing and searching activities, which is part of a navigational userprofile which includes preferences and all the aspects related to community involvement; and second, by reusing all the knowledge which has been extracted from previous usage from other users with similar profiles. This can be accomplished in terms of narrowing and focusing the search results and browsing options through the use of a recommendation system which organizes such results in the most appropriatemanner, using ontologies and concepts drawn from the semantic web field. The complete integration of the experience of use of a digital library in the learning process is also pursued. Both the usage and information organization can be also exploited to extract useful knowledge from the way users interact with a digital library, knowledge that can be used to improve several design aspects of the library, ranging from internal organization aspects to human factors and user interfaces. Although this project is still on an early development stage, it is possible to identify all the desired functionalities and requirements that are necessary to fully integrate the use of a digital library in an e-learning environment.

Design and evaluation of learning algorithms for dynamic resource management in virtual networks

Network virtualisation is considerably gaining attentionas a solution to ossification of the Internet. However, thesuccess of network virtualisation will depend in part on how efficientlythe virtual networks utilise substrate network resources.In this paper, we propose a machine learning-based approachto virtual network resource management. We propose to modelthe substrate network as a decentralised system and introducea learning algorithm in each substrate node and substrate link,providing self-organization capabilities. We propose a multiagentlearning algorithm that carries out the substrate network resourcemanagement in a coordinated and decentralised way. The taskof these agents is to use evaluative feedback to learn an optimalpolicy so as to dynamically allocate network resources to virtualnodes and links. The agents ensure that while the virtual networkshave the resources they need at any given time, only the requiredresources are reserved for this purpose. Simulations show thatour dynamic approach significantly improves the virtual networkacceptance ratio and the maximum number of accepted virtualnetwork requests at any time while ensuring that virtual networkquality of service requirements such as packet drop rate andvirtual link delay are not affected.

Analysis, improvement, and development of new firmware for the smart citizen kit ambient board

The objective of this project was to develop firmware for both the Arduino-compatible boards of the Smart Citizen initiative, and for the RTX4100 low-power WiFi.

Www-sovelluskehysten arviointi ja valinta

Useimmiten www-sovellusten käyttöliittymien rakentamiseen käytetään ohjelmistokehyksiä. Www-sovelluskehys voidaan valita lukuisista valmiista vaihtoehdoista. Valinta on kuitenkin ongelmallista. Vaikka hyviä vaihtoehtoja on paljon, www-sovelluskehykset ovat parhaimmillaan vain tietyissä tilanteissa. Tämän työn tavoitteena oli löytää keino vertailla www-sovelluskehyksiä. Menetelmän haluttiin olevan kustannustehokas. Työssä hyödynnettiin kirjallisuudesta löytyviä ohjeita ohjelmistokomponenttien ja työkalujen valintaan. Ohjeiden avulla valittiin www-sovelluskehyksien vertailuun sopivia arviointikriteerejä. Arviointikriteerien määrittelyä varten tutkittiin ohjelmistokehysten ja www-sovelluskehysten vaatimuksia. Ohjeiden avulla suoritettiin myös vertailu käytännössä. Työn tuloksena syntyneitä www-sovelluskehysten vaatimuksia ja arviointikriteerejä voidaan käyttää suoraan vertailuissa alustasta riippumatta. Tulosten avulla voidaan vähentää www-sovelluskehysten valintaan tarvittavan työn määrää. Työhön sisältyneen vertailun suorittamiseen kului kohtuullinen määrä aikaa, ja sillä kyettiin tunnistamaan eroja www-sovelluskehysten välillä.

Sähköurakoitsijan langattoman mobiiliratkaisun sunnittelu ja toteuttaminen

Kandidaatintyön tavoitteena on suunnitella ja toteuttaa tehokkaampi ajanhallintajärjestelmä sähköalan yritykseen. Ajanhallinnan tehostaminen oli tarkoitus saavuttaa siirtämällä työtuntien seuranta paperilomakkeiden käytöstä sähköiseen tietokantaan johon syötetään tiedot langattomilla päätelaitteilla. Päätelaitteiksi valittiin kämmentietokoneet jotka käyttävät tiedonsiirtoon langatonta lähiverkkoa ja yrityksen ulkopuolella GSMkännykkäverkon datasiirto-ominaisuuksia. Ohjelmisto koottiin useista eri sovelluskomponenteista Groupware-ohjelmistopaketin käyttämisen sijaan. Useiden eri sovellusten käyttö osoittautui virheeksi koska näiden erilaiset käyttöliittymät ja vaihtelevat ominaisuudet hankaloittivat käyttöä. Työn tehokkuutta mitattaessa havaittiin että järjestelmän käyttöönotto oli lisännyt ajanhallintaan liittyvien tehtävien pituutta eikä tehostanut niitä. Tämä johtuu osittain useiden eri sovellusten käytöstä ja niiden ominaisuuksien puutteista.

Predictors of smoking craving during virtual reality exposure

Cue exposure treatment (CET) consists of controlled and repeated exposure to drugrelated stimuli in order to reduce cue-reactivity. Virtual reality (VR) has proved to be a promising tool for exposition. However, identifying the variables that can modulate the efficacy of this technique is essential for selecting the most appropriate exposure modality. The aim of this study was to determine the relation between several individual variables and self-reported craving in smokers exposed to VR environments. Fortysix smokers were exposed to seven complex virtual environments that reproduce typical situations in which people smoke. Self-reported craving was selected as the criterion variable and three types of variables were selected as the predictor variables: related to nicotine dependence, related to anxiety and impulsivity, and related to the sense of presence in the virtual environments. Sense of presence was the only predictor of self-reported craving in all the experimental virtual environments. Nicotine dependence variables added predictive power to the model only in the virtual breakfast at home. No relation was found between anxiety or impulsivity and self-reported craving. Virtual reality technology can be very helpful for improving CET for substance use disorders. However, the use of virtual environments would make sense only insofar as the sense of presence was high. Otherwise, the effectiveness of exposure might be affected. © 2012 by the Massachusetts Institute of Technology.

Demonstration Platform for Visual Quality Metrics

This thesis presents two graphical user interfaces for the project DigiQ - Fusion of Digital and Visual Print Quality, a project for computationally modeling the subjective human experience of print quality by measuring the image with certain metrics. After presenting the user interfaces, methods for reducing the computation time of several of the metrics and the image registration process required to compute the metrics, and details of their performance are given. The weighted sample method for the image registration process was able to signifigantly decrease the calculation times while resulting in some error. The random sampling method for the metrics greatly reduced calculation time while maintaining excellent accuracy, but worked with only two of the metrics.