CIRCUIT - Grup de Recerca en Circuits i Sistemes de Comunicació
http://hdl.handle.net/2117/3801
2016-10-23T20:26:25ZCircuitos de capacidades conmutadas. Análisis frecuencial por ordenador
http://hdl.handle.net/2117/87859
Circuitos de capacidades conmutadas. Análisis frecuencial por ordenador
Puerta Notario, Antonio; Miró Sans, Joan M.; Sanz Postils, Margarita
El interés fundamental de los circuitos de condensadores conmutados radica en su aplicación a la realización de filtros monolíticos y de otros bloques funcionales para su tratamiento analógico de la señal. Resulta del máximo interés disponer de métodos de análisis y programas de simulación que permitan evaluar los resultados de las diferentes técnicas de síntesis.
En este artículo se presenta un programa de simulación, basado en los métodos de análisis desarrollados por los autores, que permite la obtención de las funciones de transferencia y de la respuesta frecuencial de circuitos SC. Para su realización se requiere un soporte informático reducido, lo que, junto con la facilidad de utilización, son sus características más sobresalientes.
2016-06-09T15:57:23ZPuerta Notario, AntonioMiró Sans, Joan M.Sanz Postils, MargaritaEl interés fundamental de los circuitos de condensadores conmutados radica en su aplicación a la realización de filtros monolíticos y de otros bloques funcionales para su tratamiento analógico de la señal. Resulta del máximo interés disponer de métodos de análisis y programas de simulación que permitan evaluar los resultados de las diferentes técnicas de síntesis.
En este artículo se presenta un programa de simulación, basado en los métodos de análisis desarrollados por los autores, que permite la obtención de las funciones de transferencia y de la respuesta frecuencial de circuitos SC. Para su realización se requiere un soporte informático reducido, lo que, junto con la facilidad de utilización, son sus características más sobresalientes.Dynamic geometry based on geometric constraints
http://hdl.handle.net/2117/87511
Dynamic geometry based on geometric constraints
Freixas Boleda, Marc; Joan Arinyo, Robert; Soto Riera, Antoni; Vila Marta, Sebastià
Dynamic geometry systems are tools for geometric visualization. They allow the user to define geometric elements, establish relationships between them and explore the dynamic behavior of the remaining geometric elements when one of them is moved. The main problem in dynamic geometry systems is the ambiguity that arises from operations which lead to more than one possible solution. While the user is defining the geometric construction, he is responsible to resolve these ambiguities. However, when the user is dragging a geometric element, the system is responsible to choose the intended solution, that is, the same solution that the user would select if we could ask him again. Most dynamic geometry systems deal with this problem in such a way that the solution selection method leads to a fixed dynamic behavior of the system. This is specially annoying when this behavior is not the one the user intended. In this work we propose an architecture for dynamic geometry systems built upon a set of functional units which will allow to apply some well known results from the Geometric Constraint Solving field. A functional unit called emph{filter} will provide the user with tools to unambiguously capture the expected dynamic behavior of a given geometric problem.
2016-05-31T07:28:25ZFreixas Boleda, MarcJoan Arinyo, RobertSoto Riera, AntoniVila Marta, SebastiàDynamic geometry systems are tools for geometric visualization. They allow the user to define geometric elements, establish relationships between them and explore the dynamic behavior of the remaining geometric elements when one of them is moved. The main problem in dynamic geometry systems is the ambiguity that arises from operations which lead to more than one possible solution. While the user is defining the geometric construction, he is responsible to resolve these ambiguities. However, when the user is dragging a geometric element, the system is responsible to choose the intended solution, that is, the same solution that the user would select if we could ask him again. Most dynamic geometry systems deal with this problem in such a way that the solution selection method leads to a fixed dynamic behavior of the system. This is specially annoying when this behavior is not the one the user intended. In this work we propose an architecture for dynamic geometry systems built upon a set of functional units which will allow to apply some well known results from the Geometric Constraint Solving field. A functional unit called emph{filter} will provide the user with tools to unambiguously capture the expected dynamic behavior of a given geometric problem.Formalism for a multiresolution time series database model
http://hdl.handle.net/2117/87125
Formalism for a multiresolution time series database model
Llusa Serra, Aleix; Vila Marta, Sebastià; Escobet Canal, Teresa
We formalise a specialised database management system model for time series using a multiresolution approach. These special purpose database systems store time series lossy compressed in a space-bounded storage. Time series can be stored at multiple resolutions, using distinct attribute aggregations and keeping its temporal attribute managed in a consistent way.
The model exhibits a generic approach that facilitates its customisation to suit better the actual application requirements in a given context. The elements, the meaning of which depends on a real application, are of generic nature.
Furthermore, we consider some specific time series properties that are a challenge in the multiresolution approach. We also describe a reference implementation of the model and introduce a use case based on real data.
2016-05-17T15:17:06ZLlusa Serra, AleixVila Marta, SebastiàEscobet Canal, TeresaWe formalise a specialised database management system model for time series using a multiresolution approach. These special purpose database systems store time series lossy compressed in a space-bounded storage. Time series can be stored at multiple resolutions, using distinct attribute aggregations and keeping its temporal attribute managed in a consistent way.
The model exhibits a generic approach that facilitates its customisation to suit better the actual application requirements in a given context. The elements, the meaning of which depends on a real application, are of generic nature.
Furthermore, we consider some specific time series properties that are a challenge in the multiresolution approach. We also describe a reference implementation of the model and introduce a use case based on real data.Sensibilidades de primero y segundo orden en circuitos lineales. Aplicación al desarrollo de un optimizador de la respuesta frecuencial
http://hdl.handle.net/2117/84408
Sensibilidades de primero y segundo orden en circuitos lineales. Aplicación al desarrollo de un optimizador de la respuesta frecuencial
Miró Sans, Joan Maria; Palà Schönwälder, Pere
Since using the Modified Nodal Approach formulation it is possible to obtain exact first and second arder sensitivities of any linear circuit with an affordable computational cost, first and second arder optimization algorithms may be implemented. A personal-computer program (CiOpt) to optimize the frequency response of linear lumped circuits has been implemented. It' s output are the element values that best match the obtained and the desired frequency response. CiOpt has preved to be an efficient tool in device modelling and in improving designs where the inclusion of more accurate device models distorts the desired frequency response. The implemented optimization algorithms -a quasi-Newton method (Fletcher-Powell), Newton's method and an algorithm based on the Levenberg-Marquardt method- are compared on an application example.
2016-03-15T14:51:23ZMiró Sans, Joan MariaPalà Schönwälder, PereSince using the Modified Nodal Approach formulation it is possible to obtain exact first and second arder sensitivities of any linear circuit with an affordable computational cost, first and second arder optimization algorithms may be implemented. A personal-computer program (CiOpt) to optimize the frequency response of linear lumped circuits has been implemented. It' s output are the element values that best match the obtained and the desired frequency response. CiOpt has preved to be an efficient tool in device modelling and in improving designs where the inclusion of more accurate device models distorts the desired frequency response. The implemented optimization algorithms -a quasi-Newton method (Fletcher-Powell), Newton's method and an algorithm based on the Levenberg-Marquardt method- are compared on an application example.CiOpt: a program for optimization of the frequency response of linear circuits
http://hdl.handle.net/2117/84398
CiOpt: a program for optimization of the frequency response of linear circuits
Miró Sans, Joan Maria; Palà Schönwälder, Pere
An interactive personal-computer program for optimizing the frequency response of linear lumped circuits (CiOpt) is presented. CiOpt has proved to be an efficient tool in improving designs where the inclusion of more accurate device models distorts the desired frequency response, as well as in device modeling. The outputs of CiOpt are the element values which best match the obtained and the desired frequency response. The optimization algorithms used (the Fletcher-Powell and Newton's methods, which, respectively, make use of approximate and exact second-order sensitivities) are fully described in DFD form. Analysis is carried out by obtaining the symbolic form of the transfer function H(s). An application example is presented
2016-03-15T14:21:54ZMiró Sans, Joan MariaPalà Schönwälder, PereAn interactive personal-computer program for optimizing the frequency response of linear lumped circuits (CiOpt) is presented. CiOpt has proved to be an efficient tool in improving designs where the inclusion of more accurate device models distorts the desired frequency response, as well as in device modeling. The outputs of CiOpt are the element values which best match the obtained and the desired frequency response. The optimization algorithms used (the Fletcher-Powell and Newton's methods, which, respectively, make use of approximate and exact second-order sensitivities) are fully described in DFD form. Analysis is carried out by obtaining the symbolic form of the transfer function H(s). An application example is presentedComunicaciones opticas no guiadas. Fotobalizaje
http://hdl.handle.net/2117/84393
Comunicaciones opticas no guiadas. Fotobalizaje
Miró Sans, Joan Maria; Miguel López, José María; Sanz Postils, Margarita
After a brief overview of unguided optical communications, this paper presents a system for intelligent photo-buoying of vehicles which has been implementad into a public transport controlling system in a urban traffic environment. The system utilizes a infrared bidirectional communication link for demanded data transmission from buoy to vehicle. Experimental results clearly show that infrared radiation-based systems, instead of the more frequently used microwaves-based, may offer a feasible and competitiva solution in certain types of traffic flow improvement applications.
2016-03-15T14:07:16ZMiró Sans, Joan MariaMiguel López, José MaríaSanz Postils, MargaritaAfter a brief overview of unguided optical communications, this paper presents a system for intelligent photo-buoying of vehicles which has been implementad into a public transport controlling system in a urban traffic environment. The system utilizes a infrared bidirectional communication link for demanded data transmission from buoy to vehicle. Experimental results clearly show that infrared radiation-based systems, instead of the more frequently used microwaves-based, may offer a feasible and competitiva solution in certain types of traffic flow improvement applications.Prototipo experimental para ver y oir la dinámica caótica en un circuito
http://hdl.handle.net/2117/84384
Prototipo experimental para ver y oir la dinámica caótica en un circuito
Miguel López, José María; Herranz Luis, Jaime; Miró Sans, Joan Maria; Palà Schönwälder, Pere; Sanz Postils, Margarita
Chaos, apparently disordered behaviour which is nonetheless deterministic, is a universal phenomenon which occurs in many systems in all areas of science. For it to have place, the equations describing the situation must be nonlinear. In this paper chaos is introduced via an actual circuit and, by using a digital storage osciloscope and an integrated audio amplifier, it possible to get sights and sounds of chaos.
2016-03-15T13:36:01ZMiguel López, José MaríaHerranz Luis, JaimeMiró Sans, Joan MariaPalà Schönwälder, PereSanz Postils, MargaritaChaos, apparently disordered behaviour which is nonetheless deterministic, is a universal phenomenon which occurs in many systems in all areas of science. For it to have place, the equations describing the situation must be nonlinear. In this paper chaos is introduced via an actual circuit and, by using a digital storage osciloscope and an integrated audio amplifier, it possible to get sights and sounds of chaos.Programa de simulación de circuitos analógicos lineales y de capacidades conmutadas
http://hdl.handle.net/2117/83458
Programa de simulación de circuitos analógicos lineales y de capacidades conmutadas
Miró Sans, Joan M.; Puerta Notario, Antonio; Griñó, J.M.; Sanz Postils, Margarita
2016-02-25T17:49:41ZMiró Sans, Joan M.Puerta Notario, AntonioGriñó, J.M.Sanz Postils, MargaritaRealización de condensadores electrónicamente variables: lineal o inversamente controlados por tensión
http://hdl.handle.net/2117/83408
Realización de condensadores electrónicamente variables: lineal o inversamente controlados por tensión
Miguel López, José María; Puerta Notario, Antonio; Sanz Postils, Margarita
2016-02-24T17:34:31ZMiguel López, José MaríaPuerta Notario, AntonioSanz Postils, MargaritaDesign and performance comparison of a superregenerative MPSK transceiver
http://hdl.handle.net/2117/81819
Design and performance comparison of a superregenerative MPSK transceiver
Bonet Dalmau, Jordi; López Riera, Alexis; Palà Schönwälder, Pere; Moncunill Geniz, Francesc Xavier; Babí Oller, Albert
In this paper we present a superregenerative transceiver able to switch among BPSK, QPSK and 8PSK modulations.
An HF-band proof-of-concept transceiver is implemented on an FPGA with a minimum of analog circuitry. The desire of making fair comparisons between BER figures rises a problem of clock frequency selection which is finally solved without consuming extra resources.
2016-01-21T16:02:31ZBonet Dalmau, JordiLópez Riera, AlexisPalà Schönwälder, PereMoncunill Geniz, Francesc XavierBabí Oller, AlbertIn this paper we present a superregenerative transceiver able to switch among BPSK, QPSK and 8PSK modulations.
An HF-band proof-of-concept transceiver is implemented on an FPGA with a minimum of analog circuitry. The desire of making fair comparisons between BER figures rises a problem of clock frequency selection which is finally solved without consuming extra resources.