Adquiridor de dades analògiques

L’empresa TER és una empresa dedicada al disseny i la construcció de projectes electrònics. La necessitat de comprovar el funcionament dels seus dissenys ha motivat a realitzar un projecte capaç de recollir dades significatives de diferents àmbits com pressió, voltatge, intensitat, temperatura etc. En el mercat les dos maneres més freqüents de recollir aquestes dades són per sensors que donen una equivalència d’un paràmetre físic a un rang de voltatge (0 a 10v) o per corrent (4 a 20mA). Aquestes dades seran adquirides i processades periòdicament per un microcontrolador que les emmagatzemarà una a una per posteriorment visualitzar-les en un LCD o en un programa fet per Visual Basic capaç de generar un document que guardi les dades en Excel. Com a conclusions es pot dir que s’han assolit els objectius, tant els personals com els proposats, per tal de tenir un prototip funcional

Fine-Tuning Translation Kinetics Selection as the Driving Force of Codon Usage Bias in the Hepatitis A Virus Capsid

Hepatitis A virus (HAV), the prototype of genus Hepatovirus, has several unique biological characteristics that distinguish it from other members of the Picornaviridae family. Among these, the need for an intact eIF4G factor for the initiation of translation results in an inability to shut down host protein synthesis by a mechanism similar to that of other picornaviruses. Consequently, HAV must inefficiently compete for the cellular translational machinery and this may explain its poor growth in cell culture. In this context of virus/cell competition, HAV has strategically adopted a naturally highly deoptimized codon usage with respect to that of its cellular host. With the aim to optimize its codon usage the virus was adapted to propagate in cells with impaired protein synthesis, in order to make tRNA pools more available for the virus. A significant loss of fitness was the immediate response to the adaptation process that was, however, later on recovered and more associated to a re-deoptimization rather than to an optimization of the codon usage specifically in the capsid coding region. These results exclude translation selection and instead suggest fine-tuning translation kinetics selection as the underlying mechanism of the codon usage bias in this specific genome region. Additionally, the results provide clear evidence of the Red Queen dynamics of evolution since the virus has very much evolved to re-adapt its codon usage to the environmental cellular changing conditions in order to recover the original fitness.

A gated single-photon avalanche diode array fabricated in a conventional CMOS process for triggered systems

A bidimensional array based on single-photon avalanche diodes for triggered imaging systems is presented. The diodes are operated in the gated mode of acquisition to reduce the probability to detect noise counts interfering with photon arrival events. In addition, low reverse bias overvoltages are used to lessen the dark count rate. Experimental results demonstrate that the prototype fabricated with a standard HV-CMOS process gets rid of afterpulses and offers a reduced dark count probability by applying the proposed modes of operation. The detector exhibits a dynamic range of 15 bits with short gated"on" periods of 10ns and a reverse bias overvoltage of 1.0V.

Low noise pixel detectors based on gated geiger mode avalanche photodiodes

The gated operation is proposed as an effective method to reduce the noise in pixel detectors based on Geiger mode avalanche photodiodes. A prototype with the sensor and the front-end electronics monolithically integrated has been fabricated with a conventional HV-CMOS process. Experimental results demonstrate the increase of the dynamic range of the sensor by applying this technique.

Avoiding sensor blindness in Geiger mode avalanche photodiode arrays fabricated in a conventional CMOS process

The need to move forward in the knowledge of the subatomic world has stimulated the development of new particle colliders. However, the objectives of the next generation of colliders sets unprecedented challenges to the detector performance. The purpose of this contribution is to present a bidimensional array based on avalanche photodiodes operated in the Geiger mode to track high energy particles in future linear colliders. The bidimensional array can function in a gated mode to reduce the probability to detect noise counts interfering with real events. Low reverse overvoltages are used to lessen the dark count rate. Experimental results demonstrate that the prototype fabricated with a standard HV-CMOS process presents an increased efficiency and avoids sensor blindness by applying the proposed techniques.

AMADEUS: advanced manipulation for deep underwater sampling

AMADEUS is a dexterous subsea robot hand incorporating force and slip contact sensing, using fluid filled tentacles for fingers. Hydraulic pressure variations in each of three flexible tubes (bellows) in each finger create a bending moment, and consequent motion or increase in contact force during grasping. Such fingers have inherent passive compliance, no moving parts, and are naturally depth pressure-compensated, making them ideal for reliable use in the deep ocean. In addition to the mechanical design, development of the hand has also considered closed loop finger position and force control, coordinated finger motion for grasping, force and slip sensor development/signal processing, and reactive world modeling/planning for supervisory `blind grasping¿. Initially, the application focus is for marine science tasks, but broader roles in offshore oil and gas, salvage, and military use are foreseen. Phase I of the project is complete, with the construction of a first prototype. Phase I1 is now underway, to deploy the hand from an underwater robot arm, and carry out wet trials with users.

AMADEUS: advanced manipulation for deep underwater sampling

AMADEUS is a dexterous subsea robot hand incorporating force and slip contact sensing, using fluid filled tentacles for fingers. Hydraulic pressure variations in each of three flexible tubes (bellows) in each finger create a bending moment, and consequent motion or increase in contact force during grasping. Such fingers have inherent passive compliance, no moving parts, and are naturally depth pressure-compensated, making them ideal for reliable use in the deep ocean. In addition to the mechanical design, development of the hand has also considered closed loop finger position and force control, coordinated finger motion for grasping, force and slip sensor development/signal processing, and reactive world modeling/planning for supervisory `blind grasping¿. Initially, the application focus is for marine science tasks, but broader roles in offshore oil and gas, salvage, and military use are foreseen. Phase I of the project is complete, with the construction of a first prototype. Phase I1 is now underway, to deploy the hand from an underwater robot arm, and carry out wet trials with users.

Relaxation time of processes driven by multiplicative noise

We consider systems described by nonlinear stochastic differential equations with multiplicative noise. We study the relaxation time of the steady-state correlation function as a function of noise parameters. We consider the white- and nonwhite-noise case for a prototype model for which numerical data are available. We discuss the validity of analytical approximation schemes. For the white-noise case we discuss the results of a projector-operator technique. This discussion allows us to give a generalization of the method to the non-white-noise case. Within this generalization, we account for the growth of the relaxation time as a function of the correlation time of the noise. This behavior is traced back to the existence of a non-Markovian term in the equation for the correlation function.

Transient and preparation colored-noise effects: The nonlinear relaxation-time approach

We develop a singular perturbation approach to the problem of the calculation of a characteristic time (the nonlinear relaxation time) for non-Markovian processes driven by Gaussian colored noise with small correlation time. Transient and initial preparation effects are discussed and explicit results for prototype situations are obtained. New effects on the relaxation of unstable states are predicted. The approach is compared with previous techniques.

Driving rate effects in avalanche-mediated first-order phase transitions

We study the driving-rate and temperature dependence of the power-law exponents that characterize the avalanche distribution in first-order phase transitions. Measurements of acoustic emission in structural transitions in Cu-Zn-Al and Cu-Al-Ni are presented. We show how the observed behavior emerges within a general framework of competing time scales of avalanche relaxation, driving rate, and thermal fluctuations. We confirm our findings by numerical simulations of a prototype model.

Fine-Tuning Translation Kinetics Selection as the Driving Force of Codon Usage Bias in the Hepatitis A Virus Capsid

Hepatitis A virus (HAV), the prototype of genus Hepatovirus, has several unique biological characteristics that distinguish it from other members of the Picornaviridae family. Among these, the need for an intact eIF4G factor for the initiation of translation results in an inability to shut down host protein synthesis by a mechanism similar to that of other picornaviruses. Consequently, HAV must inefficiently compete for the cellular translational machinery and this may explain its poor growth in cell culture. In this context of virus/cell competition, HAV has strategically adopted a naturally highly deoptimized codon usage with respect to that of its cellular host. With the aim to optimize its codon usage the virus was adapted to propagate in cells with impaired protein synthesis, in order to make tRNA pools more available for the virus. A significant loss of fitness was the immediate response to the adaptation process that was, however, later on recovered and more associated to a re-deoptimization rather than to an optimization of the codon usage specifically in the capsid coding region. These results exclude translation selection and instead suggest fine-tuning translation kinetics selection as the underlying mechanism of the codon usage bias in this specific genome region. Additionally, the results provide clear evidence of the Red Queen dynamics of evolution since the virus has very much evolved to re-adapt its codon usage to the environmental cellular changing conditions in order to recover the original fitness.

En busca de la lengua perfecta: pasado, presente y futuro

Análisis de las lenguas artificiales más importantes que se han creado a lo largo de la historia con el objetivo de encontrar una lengua perfecta común para todos y presentación del Rodinio, una nueva lengua artificial basada en una serie de criterios en busca de esa perfección.

SAT Modulo Linear Arithmetic for Solving Polynomial

Polynomial constraint solving plays a prominent role in several areas of hardware and software analysis and verification, e.g., termination proving, program invariant generation and hybrid system verification, to name a few. In this paper we propose a new method for solving non-linear constraints based on encoding the problem into an SMT problem considering only linear arithmetic. Unlike other existing methods, our method focuses on proving satisfiability of the constraints rather than on proving unsatisfiability, which is more relevant in several applications as we illustrate with several examples. Nevertheless, we also present new techniques based on the analysis of unsatisfiable cores that allow one to efficiently prove unsatisfiability too for a broad class of problems. The power of our approach is demonstrated by means of extensive experiments comparing our prototype with state-of-the-art tools on benchmarks taken both from the academic and the industrial world.

Disseny d'un sistema de control del consum d'aigua automàtic

Avui en dia s’ha convertit en una necessitat tenir cura del medi ambient i optimitzar els recursos naturals. En el camp per estalviar energia s’han fet grans progressos i disposem d’un gran ventall de dispositius que ens ajuden i ens faciliten l’optimització del consum d’energia. Però és una realitat que en l’estalvi del consum d’aigua el progrés ha estat molt menor i es limita molt a donar consells i repartir dosificadors d’aigua. Qui no ha vist carrers o jardins o cases inundades amb milers de litres d’aigua? Aquesta realitat m’ha portat a dissenyar i desenvolupar un prototip que em permeti tenir un millor control del consum d’aigua. El prototip, a trets principals, consta d’un sensor, una electrovàlvula i una placa Arduino Atmega. El sensor ens permet mesurar els litres consumits durant un cert període de temps. Passat aquest temps de mostreig es compara els litres consumits amb el consum habitual, en aquell període de temps. En cas de sobrepassar el volum programat es tancarà l’electrovàlvula de forma automàtica i rebrem un SMS al telèfon. L’activació de l’alarma es pot ajustar que sigui al igualar-se els dos valors, litres programats i litres consumits. També es pot programar el percentatge que cal sobrepassar de litres consumits per activar l’alarma, com el temps de mostreig. El fet de poder programar tots aquests valors ens permet fer un ajust ideal per a la instal·lació que es vol tenir controlada. A més, el prototip es pot utilitzar per enviar a la companyia d’aigua el valor del comptador de forma automàtica. D’aquesta forma la companyia d’aigua també optimitza recursos estalviant-se el desplaçament de personal a la instal·lació per fer la lectura corresponent. El prototip està basat amb un Arduino Atmega que ens permet el processament de les dades programades i capturades pel sensor. També s’ha incorporat una pantalla TFT Touch 2’8”, que permet visualitzar i programar els valors d’una forma molt més intuïtiva. Per enviar els SMS s’utilitza una placa d’Arduino Cel·lular Shield - SM5100B, a la qual només cal afegir una targeta SIM. A priori, el prototip té un elevat cost al fabricar una sola unitat i pot semblar poc útil. Però ens pot estalviar alguna sorpresa en les factures d’aigua si tenim una fuita i no ens n’adonem fins a veure el rebut de la companyia. Si es fabriqués a grans quantitats es podria abaratir el preu i fer-lo encara més engrescador.

Touching the void: exploring virtual objects through a vibrotactile glove

This paper describes a simple low-cost approach toadding an element of haptic interaction within a virtualenvironment. Using off-the-shelf hardware and software wedescribe a simple setup that can be used to explore physically virtual objects in space. This setup comprises of a prototype glove with a number of vibrating actuators to provide the haptic feedback, a Kinect camera for the tracking of the user's hand and a virtual reality development environment. As proof of concept and to test the efficiency of the system as well as its potential applications, we developed a simple application where we created 4 different shapes within a virtual environment in order to try toexplore them and guess their shape through touch alone.