1,185 research outputs found

    Data reduction in the ITMS system through a data acquisition model with self-adaptive sampling rate

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    Long pulse or steady state operation of fusion experiments require data acquisition and processing systems that reduce the volume of data involved. The availability of self-adaptive sampling rate systems and the use of real-time lossless data compression techniques can help solve these problems. The former is important for continuous adaptation of sampling frequency for experimental requirements. The latter allows the maintenance of continuous digitization under limited memory conditions. This can be achieved by permanent transmission of compressed data to other systems. The compacted transfer ensures the use of minimum bandwidth. This paper presents an implementation based on intelligent test and measurement system (ITMS), a data acquisition system architecture with multiprocessing capabilities that permits it to adapt the system’s sampling frequency throughout the experiment. The sampling rate can be controlled depending on the experiment’s specific requirements by using an external dc voltage signal or by defining user events through software. The system takes advantage of the high processing capabilities of the ITMS platform to implement a data reduction mechanism based in lossless data compression algorithms which are themselves based in periodic deltas

    Event Recognition Using Signal Spectrograms in Long Pulse Experiments

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    As discharge duration increases, real-time complex analysis of the signal becomes more important. In this context, data acquisition and processing systems must provide models for designing experiments which use event oriented plasma control. One example of advanced data analysis is signal classification. The off-line statistical analysis of a large number of discharges provides information to develop algorithms for the determination of the plasma parameters from measurements of magnetohydrodinamic waves, for example, to detect density fluctuations induced by the Alfvén cascades using morphological patterns. The need to apply different algorithms to the signals and to address different processing algorithms using the previous results necessitates the use of an event-based experiment. The Intelligent Test and Measurement System platform is an example of architecture designed to implement distributed data acquisition and real-time processing systems. The processing algorithm sequence is modeled using an event-based paradigm. The adaptive capacity of this model is based on the logic defined by the use of state machines in SCXML. The Intelligent Test and Measurement System platform mixes a local multiprocessing model with a distributed deployment of services based on Jini

    A versatile trigger and synchronization module with IEEE1588 capabilities and EPICS support.

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    Event timing and synchronization are two key aspects to improve in the implementation of distributed data acquisition (dDAQ) systems such as the ones used in fusion experiments. It is also of great importance the integration of dDAQ in control and measurement networks. This paper analyzes the applicability of the IEEE1588 and EPICS standards to solve these problems, and presents a hardware module implementation based in both of them that allow adding these functionalities to any DAQ. The IEEE1588 standard facilitates the integration of event timing and synchronization mechanisms in distributed data acquisition systems based on IEEE 803.3 (Ethernet). An optimal implementation of such system requires the use of network interface devices which include specific hardware resources devoted to the IEE1588 functionalities. Unfortunately, this is not the approach followed in most of the large number of applications available nowadays. Therefore, most solutions are based in software and use standard hardware network interfaces. This paper presents the development of a hardware module (GI2E) with IEEE1588 capabilities which includes USB, RS232, RS485 and CAN interfaces. This permits to integrate any DAQ element that uses these interfaces in dDAQ systems in an efficient and simple way. The module has been developed with Motorola's Coldfire MCF5234 processor and National Semiconductors's PHY DP83640T, providing it with the possibility to implement the PTP protocol of IEEE1588 by hardware, and therefore increasing its performance over other implementations based in software. To facilitate the integration of the dDAQ system in control and measurement networks the module includes a basic Input/Output Controller (IOC) functionality of the Experimental Physics and Industrial Control System (EPICS) architecture. The paper discusses the implementation details of this module and presents its applications in advanced dDAQ applications in the fusion community

    Empleo de cenizas de fondo de central térmica y cal como filler en mezclas bituminosas

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    This study focuses on the characterization of bottom ash (PCC-BA) and determining the mechanical characteristics of hot mix asphalt (HMA) using PCC-BA and hydrated lime (HL) as filler. Physical and chemical characterization of the bottom ash was carried out to evaluate its eventual reutilization as filler substitute. The materials tested in this study were made using 0%, 25%, 50%, 70% and 100% of PCC-BA combined with HL. HMA mixes were evaluated in terms of their engineering properties, namely: air voids in the mixes, water sensitivity, stiffness modulus, performance in wheel tracking test and fatigue resistance. The results obtained indicate that HMA mixes with a filler blend of 70% PCC-BA and 30% HL fulfil European standards and are suitable for light traffic or small infrastructures.Este estudio se centra en la caracterización de las cenizas de fondo (PCC-BA) y la determinación de las características mecánicas de mezclas bituminosas en caliente (HMA), utilizando cenizas de fondo y la cal hidratada (HL) como filler. Se realizó la caracterización física y química de las cenizas de fondo para evaluar su empleo como sustituto de filler. Las mezclas ensayadas en este estudio se realizaron utilizando 0%, 25%, 50%, 70% y 100% de cenizas de fondo combinadas con cal hidratada. Se evaluaron propiedades ingenieriles de las mezclas bituminosas, tales como los huecos de aire en las mezclas, la sensibilidad al agua, el módulo de rigidez, el ensayo de pista y la resistencia a la fatiga. Los resultados obtenidos indican que las mezclas bituminosas fabricadas con una combinación de filler del 70% de cenizas de fondo y el 30% cal hidratada, cumplen con las normas europeas y son adecuados para su aplicación con tráficos ligeros o en pequeñas infraestructuras

    FlexiTop: A flexible and scalable network monitoring system for Over-The-Top services

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    Nowadays, the demand of Over-The-Top (OTT) services such as multimedia streaming, web services or social networking is rapidly increasing. Consequently, there is a wide interest in studying the quality of these services so that Internet Service Providers (ISP) can deliver the best experience to their clients. For this purpose, we present FlexiTop, a flexible and scalable system to actively monitor these OTT services, which allows an operator to obtain metrics with a limited resource usage. Due to the continuous evolution of OTT services, this system was designed with different approaches that can be extrapolated to future situations. By looking at the results, the proposal meets all the expectations and requirements and therefore it proves its success. The proposed design was implemented and validated with different alternatives whenever it was possible, both in wired and wireless networks. Moreover, long-time testing was performed to both ensure its stability and analyze the obtained dataThis work has been partially supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund under the project TRÁFICA (MINECO/FEDER TEC2015-69417-C2-1-R

    Transductive-Weighted Neuro-fuzzy Inference System for Tool Wear Prediction in a Turning Process

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    This paper presents the application to the modeling of a novel technique of artificial intelligence. Through a transductive learning process, a neuro-fuzzy inference system enables to create a different model for each input to the system at issue. The model was created from a given number of known data with similar features to data input. The sum of these individual models yields greater accuracy to the general model because it takes into account the particularities of each input. To demonstrate the benefits of this kind of modeling, this system is applied to the tool wear modeling for turning process.This work was supported by DPI2008-01978 COGNETCON and CIT-420000-2008-13 NANOCUT-INT projects of the Spanish Ministry of Science and Innovation.Peer reviewe

    Estimación de la resistencia a compresión simple del jabre estabilizado "in situ" con cemento como material en la formación de explanadas de carreteras

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    Granite rock has powerful alterations at several meters of depth. The clayed sand resulting is commonly known as jabre. This "in situ" mixture of cement-stabilized soil requires a laboratory formula. Even when the test section is correctly verified, the mechanical properties of the homogeneous mixture of jabre exhibit high degrees of dispersion. The laboratory work undertaken included particle-size analysis and screening, definition of liquid and plastic limits, compressive strength, dry density and moisture content over stabilized samples, modified Proctor, California Bearing Ratio (CBR) and the determination of the workability of the hydraulically bound mixtures. The stress resistance curve was analyzed by means of a multilinear model of unconfined compressive strength (UCS). Since practical engineering only requires UCS for 7 days, in order to gain greater knowledge of the material, other UCS transformations were used at other curing times such as 7, 14 and 28 days.La roca granítica presenta habitualmente un horizonte de alteración con varios metros de potencia. La arena arcillosa resultante como producto de alteración se denomina comúnmente jabre. Aunque la fórmula de trabajo de la estabilización de jabre con cemento se verifique correctamente en tramos de prueba, la estabilización "in situ" del jabre con cemento presenta habitualmente elevadas dispersiones. Entre los ensayos de laboratorio efectuados se encuentran los ensayos de análisis granulométrico, límites de Atterberg, resistencia a compresión simple (RCS), la densidad y humedad sobre probetas de suelo estabilizado, Proctor modificado, índice CBR (California Bearing Ratio) y el plazo de trabajabilidad de la mezcla con cemento. La curva de endurecimiento del suelo estabilizado fue ajustada mediante un modelo multilineal. Aunque tradicionalmente se especifique la RCS a 7 días, buscando definir un mejor comportamiento del material, los autores calcularon otros modelos de jabre estabilizado para roturas a 7, 14 y 28 días

    Estimación de la resistencia a compresión simple del jabre estabilizado “in situ” con cemento como material en la formación de explanadas de carreteras

    Get PDF
    Granite rock has powerful alterations at several meters of depth. The clayed sand resulting is commonly known as jabre. This “in situ” mixture of cement-stabilized soil requires a laboratory formula. Even when the test section is correctly verified, the mechanical properties of the homogeneous mixture of jabre exhibit high degrees of dispersion. The laboratory work undertaken included particle-size analysis and screening, defini­tion of liquid and plastic limits, compressive strength, dry density and moisture content over stabilized samples, modified Proctor, California Bearing Ratio (CBR) and the determination of the workability of the hydrauli­cally bound mixtures. The stress resistance curve was analyzed by means of a multilinear model of unconfined compressive strength (UCS). Since practical engineering only requires UCS for 7 days, in order to gain greater knowledge of the material, other UCS transformations were used at other curing times such as 7, 14 and 28 days.La roca granítica presenta habitualmente un horizonte de alteración con varios metros de potencia. La arena arcillosa resultante como producto de alteración se deno­mina comúnmente jabre. Aunque la fórmula de trabajo de la estabilización de jabre con cemento se verifique correctamente en tramos de prueba, la estabilización “in situ” del jabre con cemento presenta habitualmente elevadas dispersiones. Entre los ensayos de laboratorio efectuados se encuentran los ensayos de análisis granulo­métrico, límites de Atterberg, resistencia a compresión simple (RCS), la densidad y humedad sobre probetas de suelo estabilizado, Proctor modificado, índice CBR (California Bearing Ratio) y el plazo de trabajabilidad de la mezcla con cemento. La curva de endurecimiento del suelo estabilizado fue ajustada mediante un modelo multi­lineal. Aunque tradicionalmente se especifique la RCS a 7 días, buscando definir un mejor comportamiento del material, los autores calcularon otros modelos de jabre estabilizado para roturas a 7, 14 y 28 días
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