Design of Novel Frequency Generation Circuit with Application to Ultra-Wideband Distributed Oscillators

Given the urgence of a new paradigm in wireless digital trasmission which should allow for higher bit rate, lower latency and tigher delay constaints, it has been proposed to investigate the fundamental building blocks that at the circuital/device level, will boost the change towards a more efficient network architecture, with high capacity, higher bandwidth and a more satisfactory end user experience. At the core of each transciever, there are inherently analog devices capable of providing the carrier signal, the oscillators. It is strongly believed that many limitations in today's communication protocols, could be relieved by permitting high carrier frequency radio transmission, and having some degree of reconfigurability. This led us to studying distributed oscillator architectures which work in the microwave range and possess wideband tuning capability. As microvave oscillators are essentially nonlinear devices, a full nonlinear analyis, synthesis, and optimization had to be considered for their implementation. Consequently, all the most used nonlinear numerical techniques in commercial EDA software had been reviewed. An application of all the aforementioned techniques has been shown, considering a systems of three coupled oscillator ("triple push" oscillator) in which the stability of the various oscillating modes has been studied. Provided that a certain phase distribution is maintained among the oscillating elements, this topology permits a rise in the output power of the third harmonic; nevertheless due to circuit simmetry, "unwanted" oscillating modes coexist with the intenteded one. Starting with the necessary background on distributed amplification and distributed oscillator theory, the design of a four stage reverse mode distributed voltage controlled oscillator (DVCO) using lumped elments has been presented. All the design steps have been reported and for the first time a method for an optimized design with reduced variations in the output power has been presented. Ongoing work is devoted to model a wideband DVCO and to implement a frequency divider.

Integración de empresas: planificación y gestión del cambio

Este proyecto nace de la necesidad de realizar una integración de los sistemas informáticos de una empresa en una multinacional; las empresas disponen de servicios de outsourcing en sistemas de información. Al tratarse de una integración operativa, sólo trataremos de trasladar los servicios de centro de atención al usuario, soporte local y ofimática desde un outsourcing de servicios a otro, añadiendo los cambios de procesos necesarios para disponer de un único entorno de trabajo. El cambio de entorno de trabajo se ha de realizar sin perdida de disponibilidad ni de información.

Estudi i aplicació de les tècniques de simulació en una xarxa distribuïda

L'objectiu d'aquest treball és veure com s'apliquen aquestes tècniques en l'estudi d'un sistema informàtic distribuït

Knowledge integration within an applied mobile robot summer course

This paper presents the use of a mobile robot platform as an innovative educational tool in order to promote and integrate different curriculum knowledge. Hence, it is presented the acquired experience within a summer course named ldquoapplied mobile roboticsrdquo. The main aim of the course is to integrate different subjects as electronics, programming, architecture, perception systems, communications, control and trajectory planning by using the educational open mobile robot platform PRIM. The summer course is addressed to a wide range of student profiles. However, it is of special interests to the students of electrical and computer engineering around their final academic year. The summer course consists of the theoretical and laboratory sessions, related to the following topics: design & programming of electronic devices, modelling and control systems, trajectory planning and control, and computer vision systems. Therefore, the clues for achieving a renewed path of progress in robotics are the integration of several knowledgeable fields, such as computing, communications, and control sciences, in order to perform a higher level reasoning and use decision tools with strong theoretical base

Regulador de llum controlat per ordinador

RESUM El llum electric és un tipus d’energia amb la que s’il•lumina tot el món i s’utilitza tant per a il•luminar la nit com per a disposar de llum addicional durant el dia. L’energia es pren directament de la xarxa de subministrament elèctric i permet encendre tot tipus de focus i bombetes. Actualment la necessitat de controlar la intensitat lumínica de focus és de gran utilitat i es poden veure exemples en escenaris de teatres, concerts musicals, domòtica bàsica a vivendes, botigues, restaurants, etc. on s’incorporen aparells òptims per aquest control. Aspectes com la programació d’encesa, apagat i intensitat desitjada de focus a una hora convinguda facilita el fet de fer-ho manualment i disposar de més temps propi. L’objectiu principal d’aquest treball és dissenyar i construir un regulador de llum controlat per ordinador capac de regular la intensitat lumínica de 8 focus independentment l’un de l’altre. El control de regulació s’efectua mitjancant un programa informàtic compatible amb ordinadors que incorporin el sistema operatiu Windows i és programable en el temps permetent seleccionar la intensitat desitjada a diferents hores del dia seleccionat. Com a conclusions es pot destacar un estalvi energètic al regular la intensitat dels focus evitant així la permanent connexio a una tensió màxima de 230 VAC i la oportunitat de construir un regulador de llum amb els documents subministrats.

Estudi i aplicació de les tècniques de simulació en una xarxa distribuïda

L'objectiu d'aquest treball és veure com s'apliquen aquestes tècniques en l'estudi d'un sistema informàtic distribuït

Regulador de llum controlat per ordinador

El llum electric és un tipus d’energia amb la que s’il•lumina tot el món i s’utilitza tant per a il•luminar la nit com per a disposar de llum addicional durant el dia. L’energia es pren directament de la xarxa de subministrament elèctric i permet encendre tot tipus de focus i bombetes. Actualment la necessitat de controlar la intensitat lumínica de focus és de gran utilitat i es poden veure exemples en escenaris de teatres, concerts musicals, domòtica bàsica a vivendes, botigues, restaurants, etc. on s’incorporen aparells òptims per aquest control. Aspectes com la programació d’encesa, apagat i intensitat desitjada de focus a una hora convinguda facilita el fet de fer-ho manualment i disposar de més temps propi. L’objectiu principal d’aquest treball és dissenyar i construir un regulador de llum controlat per ordinador capac de regular la intensitat lumínica de 8 focus independentment l’un de l’altre. El control de regulació s’efectua mitjancant un programa informàtic compatible amb ordinadors que incorporin el sistema operatiu Windows i és programable en el temps permetent seleccionar la intensitat desitjada a diferents hores del dia seleccionat. Com a conclusions es pot destacar un estalvi energètic al regular la intensitat dels focus evitant així la permanent connexio a una tensió màxima de 230 VAC i la oportunitat de construir un regulador de llum amb els documents subministrats.

Automatic self-configuration of the logical network using distributed software agents

We present a system for dynamic network resource configuration in environments with bandwidth reservation. The proposed system is completely distributed and automates the mechanisms for adapting the logical network to the offered load. The system is able to manage dynamically a logical network such as a virtual path network in ATM or a label switched path network in MPLS or GMPLS. The system design and implementation is based on a multi-agent system (MAS) which make the decisions of when and how to change a logical path. Despite the lack of a centralised global network view, results show that MAS manages the network resources effectively, reducing the connection blocking probability and, therefore, achieving better utilisation of network resources. We also include details of its architecture and implementation

Dynamic bandwidth management as part of an integrated network management system based on distributed agents

We present a system for dynamic network resource configuration in environments with bandwidth reservation and path restoration mechanisms. Our focus is on the dynamic bandwidth management results, although the main goal of the system is the integration of the different mechanisms that manage the reserved paths (bandwidth, restoration, and spare capacity planning). The objective is to avoid conflicts between these mechanisms. The system is able to dynamically manage a logical network such as a virtual path network in ATM or a label switch path network in MPLS. This system has been designed to be modular in the sense that in can be activated or deactivated, and it can be applied only in a sub-network. The system design and implementation is based on a multi-agent system (MAS). We also included details of its architecture and implementation

Vulnerability assessment of distributed systems

In this project I have carried out a vulnerability assessment of a component of the Condor Middleware. In this assessment I have sought and found the more dangerous software vulnerabilities of this system, I have reported them to the development team such that they may be fixed, and thus improve the security of this distributed system, and the networks that use it.

Learning about Distributed Systems

This paper presents the "state of the art" about distributed systems and applications and it's focused on teaching about these systems. It presents different platforms where to run distributed applications and describes some development toolkits whose can be used to develop prototypes, practices and distributed applications. It also presents some existing distributed algorithms useful for class practices, and some tools to help managing distributed environments. Finally, the paper presents some teaching experiences with different approaches on how to teach about distributed systems.

Counter-ion effect on surfactant-DNA gel particles as controlled DNA delivery systems

The ability to entrap drugs within vehicles and subsequently release them has led to new treatments for a number of diseases. Based on an associative phase separation and interfacial diffusion approach, we developed a way to prepare DNA gel particles without adding any kind of cross-linker or organic solvent. Among the various agents studied, cationic surfactants offered particularly efficient control for encapsulation and DNA release from these DNA gel particles. The driving force for this strong association is the electrostatic interaction between the two components, as induced by the entropic increase due to the release of the respective counter-ions. However, little is known about the influence of the respective counter-ions on this surfactant-DNA interaction. Here we examined the effect of different counter-ions on the formation and properties of the DNA gel particles by mixing DNA (either single- (ssDNA) or double-stranded (dsDNA)) with the single chain surfactant dodecyltrimethylammonium (DTA). In particular, we used as counter-ions of this surfactant the hydrogen sulfate and trifluoromethane sulfonate anions and the two halides, chloride and bromide. Effects on the morphology of the particles obtained, the encapsulation of DNA and its release, as well as the haemocompatibility of these particles, are presented, using the counter-ion structure and the DNA conformation as controlling parameters. Analysis of the data indicates that the degree of counter-ion dissociation from the surfactant micelles and the polar/hydrophobic character of the counter-ion are important parameters in the final properties of the particles. The stronger interaction with amphiphiles for ssDNA than for dsDNA suggests the important role of hydrophobic interactions in DNA.

Computer-simulation study of magnetic relaxation in anisotropic magnetic systems

We present a computer-simulation study of the effect of the distribution of energy barriers in an anisotropic magnetic system on the relaxation behavior of the magnetization. While the relaxation law for the magnetization can be approximated in all cases by a time logarithmic decay, the law for the dependence of the magnetic viscosity with temperature is found to be quite sensitive to the shape of the distribution of barriers. The low-temperature region for the magnetic viscosity never extrapolates to a positive no-null value. Moreover our computer simulation results agree reasonably well with some recent relaxation experiments on highly anisotropic single-domain particles.