Desenvolupament d'un memetracker - rastrejador de notícies

El projecte es centra en el desenvolupament d'un recol·lector de notícies publicades a una llarga llista de blocs ampliada contínuament pel desenvolupador i pels usuaris, afegint els seus blocs preferits. L'aplicació desenvolupada realitza una recol·lecció contínua de notícies consultant les possibles novetats que apareguin en cada un dels blocs inscrits a l'aplicació. Se'ls hi aplica un classificador per idioma i per temàtica i es relaciona amb les altres notícies existents si aquestes parlen sobre el mateix tema. En l'aplicació desenvolupada hi ha la possibilitat d'escollir entre les temàtiques ofertes i en l'idioma que ha estat publicada la notícia. Pel desenvolupament del projecte s'ha desitjat que la plataforma sigui el més compatible possible amb la tecnologia actual fent servir diversos llenguatges de programació que han permès desenvolupar cada un dels algorismes necessaris pel desenvolupament global de l'aplicació; en ordre d'ús he fet servir Php, Matlab, Html, MySql, CSS3, Javascript i XML. s'ha de destacar que el projecte aporta una comoditat per tots aquells lectors de blocs que es troben tantes vegades amb notícies ja llegides en els diferents blocs que consulten.

Conceptual models for designing information systems supporting the strategic analysis of technology environments

1 6 STRUCTURE OF THIS THESIS -Chapter I presents the motivations of this dissertation by illustrating two gaps in the current body of knowledge that are worth filling, describes the research problem addressed by this thesis and presents the research methodology used to achieve this goal. -Chapter 2 shows a review of the existing literature showing that environment analysis is a vital strategic task, that it shall be supported by adapted information systems, and that there is thus a need for developing a conceptual model of the environment that provides a reference framework for better integrating the various existing methods and a more formal definition of the various aspect to support the development of suitable tools. -Chapter 3 proposes a conceptual model that specifies the various enviromnental aspects that are relevant for strategic decision making, how they relate to each other, and ,defines them in a more formal way that is more suited for information systems development. -Chapter 4 is dedicated to the evaluation of the proposed model on the basis of its application to a concrete environment to evaluate its suitability to describe the current conditions and potential evolution of a real environment and get an idea of its usefulness. -Chapter 5 goes a step further by assembling a toolbox describing a set of methods that can be used to analyze the various environmental aspects put forward by the model and by providing more detailed specifications for a number of them to show how our model can be used to facilitate their implementation as software tools. -Chapter 6 describes a prototype of a strategic decision support tool that allow the analysis of some of the aspects of the environment that are not well supported by existing tools and namely to analyze the relationship between multiple actors and issues. The usefulness of this prototype is evaluated on the basis of its application to a concrete environment. -Chapter 7 finally concludes this thesis by making a summary of its various contributions and by proposing further interesting research directions.

Assessment of left coronary artery beat-to-beat repositioning in order to propose an optimal acquisition window for coronary MRA

Introduction: Coronary magnetic resonance angiography (MRA) is a medical imaging technique that involves collecting data from consecutive heartbeats, always at the same time in the cardiac cycle, in order to minimize heart motion artifacts. This technique relies on the assumption that coronary arteries always follow the same trajectory from heartbeat to heartbeat. Until now, choosing the acquisition window in the cardiac cycle was based exclusively on the position of minimal coronary motion. The goal of this study was to test the hypothesis that there are time intervals during the cardiac cycle when coronary beat-to-beat repositioning is optimal. The repositioning uncertainty values in these time intervals were then compared with the intervals of low coronary motion in order to propose an optimal acquisition window for coronary MRA. Methods: Cine breath-hold x-ray angiograms with synchronous ECG were collected from 11 patients who underwent elective routine diagnostic coronarography. Twenty-three bifurcations of the left coronary artery were selected as markers to evaluate repositioning uncertainty and velocity during cardiac cycle. Each bifurcation was tracked by two observers, with the help of a user-assisted algorithm implemented in Matlab (The Mathworks, Natick, MA, USA) that compared the trajectories of the markers coming from consecutive heartbeats and computed the coronary repositioning uncertainty with steps of 50ms until 650ms after the R-wave. Repositioning uncertainty was defined as the diameter of the smallest circle encompassing the points to be compared at the same time after the R-wave. Student's t-tests with a false discovery rate (FDR, q=0.1) correction for multiple comparison were applied to see whether coronary repositioning and velocity vary statistically during cardiac cycle. Bland-Altman plots and linear regression were used to assess intra- and inter-observer agreement. Results: The analysis of left coronary artery beat-to-beat repositioning uncertainty shows a tendency to have better repositioning in mid systole (less than 0.84±0.58mm) and mid diastole (less than 0.89±0.6mm) than in the rest of the cardiac cycle (highest value at 50ms=1.35±0.64mm). According to Student's t-tests with FDR correction for multiple comparison (q=0.1), two intervals, in mid systole (150-200ms) and mid diastole (550-600ms), provide statistically better repositioning in comparison with the early systole and the early diastole. Coronary velocity analysis reveals that left coronary artery moves more slowly in end systole (14.35±11.35mm/s at 225ms) and mid diastole (11.78±11.62mm/s at 625ms) than in the rest of the cardiac cycle (highest value at 25ms: 55.96±22.34mm/s). This was confirmed by Student's t-tests with FDR correction for multiple comparison (q=0.1, FDR-corrected p-value=0.054): coronary velocity values at 225, 575 and 625ms are not much different between them but they are statistically inferior to all others. Bland-Altman plots and linear regression show that intra-observer agreement (y=0.97x+0.02 with R²=0.93 at 150ms) is better than inter-observer (y=0.8x+0.11 with R²=0.67 at 150ms). Discussion: The present study has demonstrated that there are two time intervals in the cardiac cycle, one in mid systole and one in mid diastole, where left coronary artery repositioning uncertainty reaches points of local minima. It has also been calculated that the velocity is the lowest in end systole and mid diastole. Since systole is less influenced by heart rate variability than diastole, it was finally proposed to test an acquisition window between 150 and 200ms after the R-wave.

Modeling stochasticity and robustness in gene regulatory networks.

MOTIVATION: Understanding gene regulation in biological processes and modeling the robustness of underlying regulatory networks is an important problem that is currently being addressed by computational systems biologists. Lately, there has been a renewed interest in Boolean modeling techniques for gene regulatory networks (GRNs). However, due to their deterministic nature, it is often difficult to identify whether these modeling approaches are robust to the addition of stochastic noise that is widespread in gene regulatory processes. Stochasticity in Boolean models of GRNs has been addressed relatively sparingly in the past, mainly by flipping the expression of genes between different expression levels with a predefined probability. This stochasticity in nodes (SIN) model leads to over representation of noise in GRNs and hence non-correspondence with biological observations. RESULTS: In this article, we introduce the stochasticity in functions (SIF) model for simulating stochasticity in Boolean models of GRNs. By providing biological motivation behind the use of the SIF model and applying it to the T-helper and T-cell activation networks, we show that the SIF model provides more biologically robust results than the existing SIN model of stochasticity in GRNs. AVAILABILITY: Algorithms are made available under our Boolean modeling toolbox, GenYsis. The software binaries can be downloaded from http://si2.epfl.ch/ approximately garg/genysis.html.

Application for fault location in electrical power distribution systems

Fault location has been studied deeply for transmission lines due to its importance in power systems. Nowadays the problem of fault location on distribution systems is receiving special attention mainly because of the power quality regulations. In this context, this paper presents an application software developed in Matlabtrade that automatically calculates the location of a fault in a distribution power system, starting from voltages and currents measured at the line terminal and the model of the distribution power system data. The application is based on a N-ary tree structure, which is suitable to be used in this application due to the highly branched and the non- homogeneity nature of the distribution systems, and has been developed for single-phase, two-phase, two-phase-to-ground, and three-phase faults. The implemented application is tested by using fault data in a real electrical distribution power system

Estudi del model dinàmic d’un robot submarí d’intervenció (IAUV) composat per un vehicle i un braç manipulador

Fins a la data d’avui, el grup VICOROB de la Universitat de Girona ha desenvolupat diversos vehicles autònoms (GARBÍ, URIS i ICTINEU). El projecte que comença aquest any té com objectiu desenvolupar un nou vehicle submarí autònom amb capacitat d’intervenció (I-AUV) gràcies a un braç manipulador. Aquest projecte final de carrera té com objectiu desenvolupar en entorn MATLAB un simulador d’un I-AUV, format per un AUV i un braç manipulador de n graus de llibertat per tal d’avaluar les reaccions dels moviments del braç, amb càrrega i sense, sobre el robot, iviceversa

Segmentació de teixit i lesions en imatges de MRI de malalts d'esclerosi múltiple

Actualment, en l'àmbit mèdic, la ressonància magnètica, MRI Magnetic Resonance Imaging, és un dels sistemes més utilitzats per a la realització de diagnòstics i el seguiment de l'evolució de malalties com l'esclerosi múltiple (EM). No obstant, la gran quantitat d'informació que proporciona aquesta modalitat té com a conseqüència una tasca feixuga d'anàlisi i d'interpretació per part dels radiòlegs i neuròlegs. L'objectiu general d'aquest projecte és desenvolupar un sistema per ajudar als metges a segmentar les imatges de MRI del cervell. S'ha implementat amb MATLAB. Durant tot el procés s'han utilitzat dades sintètiques, de la base de dades simulada BrainWeb, i reals, proporcionades pels grup de metges col•laboradors amb el grup VICOROB.El projecte s'emmarca dins d'un projecte de recerca del grup de Visió per Computador i Robòtica de la Universitat de Girona

Disseny de controladors òptims per al robot Pioneer

Aquest projecte titulat: “Disseny de controladors òptims per al robot Pioneer”, té com a funcióincloure en la recerca, que ja està iniciada, del control del Robot Pioneer 2DX, una novaversió d’agents go to per al funcionament del robot.La problemàtica que ens trobem és sobretot per al primer controlador. Fins ara el sistemamulti-agent fet, feia servir un agent go to que generava la trajectòria a seguir i la controlavamitjançant un PID. Introduint un mètode geomètric com és el cas del pure pursuit la cosa escomplica ja que és més complex l’ajustament del funcionament d’aquest. Centrant-nos encanvi el cas del segon controlador el problema es simplifica ja que l’ajustatge d’aquestmateix es pot realitzar de manera empírica i la problemàtica per a la situació en concret esmillora amb major facilitat.És per aquest motiu, sobretot pel primer controlador, que s’han hagut de realitzar algunesmodificacions en el plantejament del projecte al llarg d’aquest. En un principi estava pensatcrear aquest controlador a través de Matlab® mitjançant l’eina Simulink® però perproblemes de software en un moment donat hem hagut de redirigir el projecte cap alllenguatge base de l’estructura multi-agent com és el C++. Per aquest motiu també s’hahagut de prescindir de la implementació d’aquests també en l’estructura LabView®.

Redes neuronales multimodelo aplicadas al control de sistemas

En este proyecto se plantea un nuevo modelo de red neuronal llamado multimodelo. Si en un modelo convencional de red neuronal obtenemos la salida a partir de una serie de parámetros, en un sistema multimodelo recalculamos la salida a partir de los mismos valores de entrada, pero variando los parámetros. Con esto se consigue una mayor muestra de salidas, que permiten decidir cuales son los parámetros más acertados (los que devuelven una salida más cercana a la salida deseada del sistema de control). Para llevar a cabo este proyecto se ha hecho uso de Matlab 7.3 (R2006b).

Caracterització estadística dels pics de correlació a GPS

Aquest projecte es centra a donar una caracterització estadística del valor que tenen els pics de correlació sota diferents escenaris d’adquisició a un receptor GPS. En primer lloc, s’ha volgut donar una visió general de tots els fonaments del sistema GPS per tal de poder entendre el seu funcionament. A continuació, s’ha passat a analitzar el bloc d’adquisició d’un receptor GPS. Primer, hem estudiat quines operacions es realitzen en aquest bloc i quines són les diferents formes d’implementar-lo. Seguidament, sota un escenari d’adquisició per cerca de fase de codi en paral·lel i utilitzant integracions coherents, s’han estudiat les distribucions estadístiques de les pdf’s obtingudes pels pics de correlació de senyal+soroll i pels pics de correlació de només soroll, i s’ha vist com aquestes fan modificar la corba ROC del receptor . Les simulacions s’han realitzat amb MATLAB i en diferents escenaris d’adquisició per tal de poder comparar com varien les estadístiques obtingudes en casos diferents.

Estudio del péndulo doble

L'objectiu del projecte “Estudi del pèndol doble” és analitzar eldesenvolupament d'aquest sistema físic i del seu comportament dinàmicmitjançant aplicacions informàtiques.En l'estudi es van utilitzar dues aplicacions informàtiques: MATLAB en laseva versió 2009b per a l'anàlisi del pèndol simple, i la setzena versió deMAPLE per a la resolució i l'anàlisi gràfica de les equacions diferencials quegovernen el sistema.Un cop analitzat el sistema s'aplicarà a un problema mecànic, que seràla creació d'una atracció de fira basada en aquest mecanisme.L'anàlisi del problema mecànic es tindrà en compte optant per diversesconfiguracions i, un cop escollits els paràmetres més adequats, escorregiran en funció de les necessitats de fabricació per a tornar a obtenirles dades i poder analitzar si són vàlides.

Do labour mobility and networks foster geographical knowledge diffusion? The case of European regions

The goal of this paper is twofold: first, we aim to assess the role played by inventors’ cross-regional mobility and networks of collaboration in fostering knowledge diffusion across regions and subsequent innovation. Second, we intend to evaluate the feasibility of using mobility and networks information to build cross-regional interaction matrices to be used within the spatial econometrics toolbox. To do so, we depart from a knowledge production function where regional innovation intensity is a function not only of the own regional innovation inputs but also external accessible R&D gained through interregional interactions. Differently from much of the previous literature, cross-section gravity models of mobility and networks are estimated to use the fitted values to build our ‘spatial’ weights matrices, which characterize the intensity of knowledge interactions across a panel of 269 regions covering most European countries over 6 years.

Study and implementation of some quantitative trading models

Quantitative or algorithmic trading is the automatization of investments decisions obeying a fixed or dynamic sets of rules to determine trading orders. It has increasingly made its way up to 70% of the trading volume of one of the biggest financial markets such as the New York Stock Exchange (NYSE). However, there is not a signi cant amount of academic literature devoted to it due to the private nature of investment banks and hedge funds. This projects aims to review the literature and discuss the models available in a subject that publications are scarce and infrequently. We review the basic and fundamental mathematical concepts needed for modeling financial markets such as: stochastic processes, stochastic integration and basic models for prices and spreads dynamics necessary for building quantitative strategies. We also contrast these models with real market data with minutely sampling frequency from the Dow Jones Industrial Average (DJIA). Quantitative strategies try to exploit two types of behavior: trend following or mean reversion. The former is grouped in the so-called technical models and the later in the so-called pairs trading. Technical models have been discarded by financial theoreticians but we show that they can be properly cast into a well defined scientific predictor if the signal generated by them pass the test of being a Markov time. That is, we can tell if the signal has occurred or not by examining the information up to the current time; or more technically, if the event is F_t-measurable. On the other hand the concept of pairs trading or market neutral strategy is fairly simple. However it can be cast in a variety of mathematical models ranging from a method based on a simple euclidean distance, in a co-integration framework or involving stochastic differential equations such as the well-known Ornstein-Uhlenbeck mean reversal ODE and its variations. A model for forecasting any economic or financial magnitude could be properly defined with scientific rigor but it could also lack of any economical value and be considered useless from a practical point of view. This is why this project could not be complete without a backtesting of the mentioned strategies. Conducting a useful and realistic backtesting is by no means a trivial exercise since the \laws" that govern financial markets are constantly evolving in time. This is the reason because we make emphasis in the calibration process of the strategies' parameters to adapt the given market conditions. We find out that the parameters from technical models are more volatile than their counterpart form market neutral strategies and calibration must be done in a high-frequency sampling manner to constantly track the currently market situation. As a whole, the goal of this project is to provide an overview of a quantitative approach to investment reviewing basic strategies and illustrating them by means of a back-testing with real financial market data. The sources of the data used in this project are Bloomberg for intraday time series and Yahoo! for daily prices. All numeric computations and graphics used and shown in this project were implemented in MATLAB^R scratch from scratch as a part of this thesis. No other mathematical or statistical software was used.

Disseny i implementació d'un sistema de navegació inercial i la seva aplicació a la robòtica mòbil

La UdG desposa de diversos robots mòbils per a finalitats docents i de recerca que utilitzen sistemes de localització incremental mitjançant bàsicament encoders incrementals. Actualment, en el mercat de l’automoció s’ha desenvolupat una sèrie de dispositius electrònics tals com brúixoles electròniques, acceleròmetres, giroscòpics, etc. L’objectiu és dissenyar i construir un sistema de navegació inercial format per un acceleròmetre, un giroscòpic, una brúixola i un microcontrolador encarregat de governar les ordres. El llenguatge utilitzat serà l’assemblador, ja que es pretén una execució molt eficient de les rutines creades. Les dades obtingudes es transmetran a l’ordinador per mitjà del protocol RS-232 i un programa en C emmagatzemarà les dades en un document de text. Aquestes dades seran tractades amb l’entorn MATLAB per tal d’interpretar-les i representar-les gràficament. Per analitzar el funcionament del sistema s’utilitzarà la plataforma PRIM

Estudi i implementació de tècniques de reconeixement facial

Estudi i implementació de les tècniques de reconeixement facial més conegudes: eigenfaces, fisherfaces i ASM. El resultat és una aplicació implementada en Matalab que permet realitzar el reconeixement de persones en temps real.