1,456 research outputs found
CWDM self-referencing sensor network based on ring resonators in reflective configuration
A new scalable self-referencing sensor network with low insertion losses implemented in Coarse Wavelength Division Multiplexing (CWDM) technology is reported. It allows obtaining remote self-referenced
measurements with a full-duplex fibre downlead up to 35 km long, with no need for optical amplification. Fibre Bragg gratings (FBG) are used in order to achieve a reflective configuration, thus increasing the sensitivity of the optical transducers. Low-cost off-the-shelf devices in CWDM technology can be used to implement and scale the network. Ring resonator (RR) based
incoherent interferometers at the measuring points are used as selfreferencing
technique. A theoretical analysis of power budget of the topology is reported, with a comparison between the proposed network and a conventional star topology. Finally, the new configuration has been experimentally demonstrated.This work has been supported by CICYT:TIC2003-03783, UC3M:FAVICOBIS and CAM:FACTOTEM-CM (S-0505/ESP/000417).Publicad
Toma de decisiones, valores y factores contextuales, su relaciĂłn con el consumo de energĂa elĂ©ctrica
Se sometiĂł a prueba empĂrica un modelo correlacional de consumo sobre energĂa elĂ©ctrica en viviendas de la Ciudad de MĂ©xico. Se seleccionaron 224 amas de casa mediante un mues-treo polietápico por estratos, medio y bajo, utilizando como referencia de análisis el listado de unidades habitacionales (ProcuradurĂa Social del Gobierno del Distrito Federal, 2006). Se planteĂł que el consumo de energĂa elĂ©ctrica en viviendas dependĂa de la toma de decisiones del ama de casa, factores contextuales y valores y estarĂa asociado a variables demográfi-cas. Los resultados sugieren que el consumo de energĂa elĂ©ctrica depende, en parte, del in-greso familiar mensual, el nĂşmero de habitantes en la vivienda y de que las personas tomen decisiones razonadas al consumir dicha energĂa.An empirical correlation model was tested on electric power consumption in Mexico City homes. 224 housewives were selected in a sample including middle and lower strata. The reference used in the analysis was the list of housing units (ProcuradurĂa Social del Go-bierno del Distrito Federal, 2006). It was suggested that the consumption of electricity in homes depended on the decisions of the housewife, context, and values, and would be as-sociated with demographic variables. Results suggest that the power consumption depends partly on the monthly family income, number of inhabitants in the housing and people to make informed decisions
Development of an Analytic Nodal Diffusion Solver in Multigroups for 3D Reactor Cores with Rectangular or Hexagonal Assemblies.
More accurate modelling of physical phenomena involved in present and future nuclear reactors requires a multi-scale and multi-physics approach. This challenge can be accomplished by the coupling of best-estimate core-physics, thermal-hydraulics and multi-physics solvers. In order to make viable that coupling, the current trends in reactor simulations are along the development of a new generation of tools based on user-friendly, modular, easily linkable, faster and more accurate codes to be integrated in common platforms. These premises are in the origin of the NURESIM Integrated Project within the 6th European Framework Program, which is envisaged to provide the initial step towards a Common European Standard Software Platform for nuclear reactors simulations. In the frame of this project and to reach the above-mentioned goals, a 3-D multigroup nodal solver for neutron diffusion calculations called ANDES (Analytic Nodal Diffusion Equation Solver) has been developed and tested in-depth in this Thesis. ANDES solves the steady-state and time-dependent neutron diffusion equation in threedimensions and any number of energy groups, utilizing the Analytic Coarse-Mesh Finite-Difference (ACMFD) scheme to yield the nodal coupling equations. It can be applied to both Cartesian and triangular-Z geometries, so that simulations of LWR as well as VVER, HTR and fast reactors can be performed. The solver has been implemented in a fully encapsulated way, enabling it as a module to be readily integrated in other codes and platforms. In fact, it can be used either as a stand-alone nodal code or as a solver to accelerate the convergence of whole core pin-by-pin code systems. Verification of performance has shown that ANDES is a code with high order definition for whole core realistic nodal simulations. In this paper, the methodology developed and involved in ANDES is presented
Self-Referencing Fiber-Optic Intensity Sensors Using Ring Resonators and Fiber Bragg Gratings
An improved ring resonator self-referencing technique in a new reflection configuration for remote fiber-optic intensity sensors is demonstrated using fiber Bragg gratings. Sensor sensitivity doubles and a single fiber lead is used. The sensor is interrogated at two subcarrier frequencies having a high rejection of interference from laser source intensity fluctuations and loss in the fiber lead. We experimentally demonstrate the efficiency of the new reflection configuration, the usefulness of the theoretical model proposed, and discuss design parameters for optimum insertion lossesThis work was supported in part by CICYT (TIC2003-03783 and TEC2006-13273-C03-03-MIC), in part by UC3M (FAVICOBIS), in part by CAM (FACTOTEM-CM:S-0505/ESP/000417), and in part by COST 299.Publicad
CaracterizaciĂłn clĂnica de la poblaciĂłn con disfunciĂłn acomodativa sintomática: insuficiencia y exceso de acomodaciĂłn
Las tasas de prevalencia de las disfun-ciones acomodativas en poblaciĂłn no-prĂ©sbita se sitĂşan entre valores del 2% y 60%. Su variabilidad y alta presencia en la poblaciĂłn, justifica el estudio de este tipo de alteraciones. Uno de los objetivos de la Tesis ha sido la caracterizaciĂłn de la po-blaciĂłn con insuficiencia y exceso de aco-modaciĂłn que presenta sĂntomas visuales, con edades comprendidas entre 6 y 40 años.Otro de los objetivos fue el estudio de la relaciĂłn entre la edad y la amplitud de acomodaciĂłn de nuestra muestra.El tercer y Ăşltimo objetivo fue el análisis de la capacidad diagnĂłstica de la diferencia entre el error refractivo pre y post cicloplegia, definido como error refractivo latente (ERL), en la poblaciĂłn miope con exceso de acomodaciĂłn..
RelaciĂłn entre la resiliencia personal y las estrategias de afrontamiento en estudiantes
El propĂłsito de esta investigaciĂłn fue averiguar quĂ© estrategias de afrontamiento eran las que utilizaban aquellos alumnos más resilientes personalmente, o dicho en otras palabras, quĂ© estrategias de afrontamiento usaban aquellos estudiantes que eran más eficaces a la hora de manejar y superar situaciones estresantes producidas en su vida cotidiana. Se realizĂł un estudio descriptivo mediante encuesta. Participaron 620 estudiantes, 334 alumnos de bachillerato y 286 estudiantes universitarios, el 50% mujeres. Cumplimentaron dos instrumentos de medida: una escala de Resiliencia y el cuestionario COPE-28 de Estrategias de Afrontamiento. A la vista de los resultados, existe relaciĂłn positiva entre la Resiliencia Personal y las estrategias de afrontamiento PlanificaciĂłn, Afrontamiento Activo, Apoyo Instrumental, Humor, ReinterpretaciĂłn Positiva y AceptaciĂłn. En cambio, existe relaciĂłn negativa entre la Resiliencia Personal y DesconexiĂłn Conductual. Concluimos que los alumnos más resilientes personalmente utilizan en mayor medida el Afrontamiento Activo, PlanificaciĂłn, Apoyo Instrumental, Humor, ReinterpretaciĂłn Positiva y AceptaciĂłn. En cambio, utilizan menos la DesconexiĂłn Conductual como estrategia de afrontamiento para superar situaciones crĂticas de estrĂ©s.Aim: The aim in this study was to find the relationship between Personal Resilience and Coping Strategies. Methodology: Descriptive study through inquiry. 620 students which 334 were high school degree students and 286 university students; 50 % of them were women. Two questionnaires were completed: one about Resilience and other about Coping Strategies COPE-28. Results: In one hand, there are positive correlation between Personal Resilience and Active Coping, Planning, Instrumental Support, Humor, Positive Reframing and Acceptance. In other hand, there are negative correlation between Personal Resilience and Behavioral Disengagement. In conclusion, the most significant findings show that the resilient students use more Active Coping, Planning, Instrumental Support, Humor, Positive Reframing and Acceptance. The less resilient studens use more Behavioral Disengagement.peerReviewe
Temperature impairment characterization in radio-over-multimode fiber systems
Arbitrary operating conditions, such as the temperature dependence in the fiber link impose a challenge for the extension of radio-over-multimode fiber techniques. Temperature impairment characterization is analyzed over the broadband transmission bands that can be present in the frequency response of multimode fiber (MMF) supporting multiple-GHz carriers delivering schemes. Experimental results show that these transmission bands are dramatically influenced by the hysteresis of heating and cooling temperature cycles, respectively. The influence of the MMF graded index exponent tolerance on frequency response at higher bands is also analyzed. And this variation can be directly attributed to environmental temperature changes that could affect the MMF link. Additionally, selective mode-launching schemes combined with the use of narrow line-width optical sources are experimentally demonstrated to enable broadband transmission, not only at short but also at middle-reach distances over MMFs.This work was supported by Spanish CICyT project TEC2009-14718-C03-03 from the Spanish Ministry of Science, and by project FACTOTEM-II-CM: S2009/ESP-1781 of Comunidad AutĂłnoma de Madrid.Publicad
Competencias básicas: un marco legislativo, teórico y aplicativo
El presente trabajo pretende realizar un recorrido por las principales directrices educativas españolas contemporáneas que más han influido en la mayor parte de los discentes españoles como son la Ley General de 1970, la Ley Orgánica General del Sistema Educativo o LOGSE, la malograda Ley de Calidad Educativa o LOCE y la actual Ley Orgánica de EducaciĂłn o LOE hasta llegar a la progresiva implantaciĂłn de las Competencias Básicas, recopilando en las mismas las diversas aportaciones legales mencionadas, asumiendo el marco teĂłrico interno _legal_ y externo _directrices europeas_ y proponiendo someramente un marco de aplicaciĂłn en el aula respecto a su desarrollo, implantaciĂłn y evaluaciĂłn, desde corrientes pedagĂłgicas liberadoras y humanĂsticas como la concientizaciĂłn de Freire, el currĂculo praxiolĂłgico, y, más modernamente el Informe Delors sobre la EducaciĂłn de 1996 de la UNESCO.The present work a tour tries to realize for the principal contemporary educational Spanish directives who more have influenced most of the Spanish pupils since are the General Law of 1970, the Organic General Law of the Educational System or LOGSE, the unsuccessful Law of Educational Quality or LOCE and the current Organic Law of Education or LOE up to coming to the progressive implantation of the Basic Competitions, compiling in the same diverse legal mentioned contributions, assuming the theoretical internal frame _legal_ and day pupil _European laws_ and proposing like a frame of application in the classroom with regard to his development, implantation and evaluation, from liberating and humanistic pedagogic currents as Freire’s concientizacion, the praxiological curricula, and nowadays the 1996 UNESCO Delor´s Inform about education.peerReviewe
Temperature Impairment Characterization in Radio-Over-Multimode Fiber Systems
The proceeding at: SPIE Photonics West 2012.Broadband Access Communication Technologies VI., took place in 2012, January 21-26, in San Francisco, California (USA). The event Web site at: http://spie.org/conferences-and-exhibitions/past-events/past-conferences-and-exhibitions/past-events/photonics-west/photonics-west-2012An emerging theme in next-generation access research includes seamless wireline-wireless convergence addressed by Radio-over-Fiber (RoF) technologies. Optical cabling solutions offer th e possibility for semi-transparent transport through the access network microwave to mm-wave radio carriers commonly employed for creating high-capacity picocell wireless networks, attending present demands from the wireless technologies, with portable/mobile devices converging with photonics. Advanced RoF techniques can efficiently generate and transport such carriers, and deliver them to simplified antenna stations or radio access points (RAPs). Thus, they can convey high data rates in comprehensive modulation formats on multiple-GHz carriers in MMF networks. Selective mode-launching schemes combined with the use of narrow linewidth optical sources are experimentally demonstrated to enable broadband RF, microwave and mm-wave transmission in short- and middle-reach distances over silica-based multimode optical fibers (MMFs); and are rev iewed in this pap er. However, arbitrary operating conditions, such as the temperature dependence in the fiber link, impose a great challenge for the extension of the RoMMF technology. Temperature impairment ch aracterization is analyzed over the broadband transmission bands that are present, under certain operating link conditions, in the frequency response performance of MMF to support multiple GHz carrier delivering schemes, thus contributing to fault link prevention.Publicad
Polymer Optical Fiber Intensity-Based Sensor for Liquid-Level Measurements in Volumetric Flasks for Industrial Application
A low-cost intensity-based polymer optical fiber (POF) sensor for liquid detection applied to volumetric flasks is presented. Experimental results demonstrate the viability of the POF-based sensor system in a high-accuracy liquid level measurement scenario. Moreover, a wireless mesh sensor network based on ZigBee specification protocol to address multiplexed POF-based sensor is also developed. Experimental results demonstrate the feasibility to address a high number of optical sensors in an industrial process framework by means of this low-cost wireless solution.This work has been supported by Spanish CICyT project
TEC2009-14718-C03-03 (DEDOS) and by FACTOTEM-2/
2009/S2009/ESP-1781.Publicad
- …