27 research outputs found

    An Incremental and Model Driven Approach for the Dynamic Reconfiguration of Cloud Application Architectures

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    In incremental development approaches, the integration of new services into the actual cloud application may trigger the dynamic reconfiguration of the cloud application architecture, thus changing its structure and behavior at runtime. This paper presents a model driven approach that uses the specification of how the integration of new services will change the current cloud application architecture to obtain: i) the orchestration of services, ii) skeletons of interface implementations, and iii) the operationalization of reconfiguration actions to be applied at runtime. This approach follows the DIARy-process, which defines the activities needed to reconfigure dynamically the architecture of cloud services. The feasibility of the approach is illustrated by means of a case study that uses Microsoft Azure© as a service deployment platform. WCF Workflow services are generated and deployed for orchestration, whereas XML transformation files are generated to update services’ binding configurations at runtim

    Incremental Integration of Microservices in Cloud Applications

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    Microservices have recently appeared as a new architectural style that is native to the cloud. The high availability and agility of the cloud demands organizations to migrate or design microservices, promoting the building of applications as a suite of small and cohesive services (microservices) that are independently developed, deployed and scaled. Current cloud development approaches do not support the incremental integration needed for microservice platforms, and the agility of getting new functionalities out to customers is consequently affected by the lack of support for the integration design and automation of the development and deployment tasks. This paper presents an approach for the incremental integration of microservices that will allow developers to specify and design microservice integration, and provide mechanisms with which to automatically obtain the implementation code for business logic and interoperation among microservices along with deployment and architectural reconfiguration scripts specific to the cloud environment in which the microservice will be deployed

    A Novel Adaptive Synchronous Rectification System for Low Output Voltage Isolated Converters

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    The design of efficient isolated low output voltage converters is a major concern due to their widespread use. One of the preferred methods used to maximize their efficiency is synchronous rectification (SR), i.e., the replacement of the secondary side diodes with MOSFETs to decrease conduction losses. However, depending on the topology being used, SR might not provide the required efficiency improvement or even be easily implemented. This paper presents a novel SR system that can be applied to converters with symmetrically driven transformers and to converters from the flyback family; in both cases, the proposed system adaptively generates a control signal that controls a synchronous rectifier MOSFET placed in parallel with each diode, turning it on during the conduction intervals of the diodes. The proposed system uses only information from the secondary side, thus avoiding breaking the isolation barrier; it can be built using a few low-cost analog components, is reliable and simple, and could be easily implemented in an integrated circuit. Up to a 3% improvement is demonstrated in a 3.3-5-V 120-W push-pull converter, and up to a 2.5% improvement is obtained in a 5-V 50-W flyback converter, with both of them designed for telecom application

    Aspectos medioambientales en los anĂĄlisis de eficiencia

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    El presente estudio se focalizó en una revisión de investigaciones aplicadas utilizando variables agroclimåticas con la incorporación de efectos medio ambientales en el anålisis de la eficiencia. Se consideró el anålisis econométrico, el enfoque de la eficiencia técnico-ambiental, el enfoque eco-eficiencia, el enfoque metafronteras, enfoque de la eficiencia ambiental, el balance de materiales. Las conclusiones del estudio evidencia la necesidad de utilizar el anålisis de eficiencia u productividad considerando los factores medioambientales y las variaciones del cambio climåtico. La importancia de estos factores incide en los procesos productivos para medir la eficiencia y la productividad. Se recomienda la investigación en el desarrollo de nuevas metodologías en esta parcela del anålisis de eficiencia, y también que se apliquen las ya existentes para no llegar a malas estimaciones al no considerar la realidad que nos rodea

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

    Municipio y educaciĂłn : reflexiones, experiencias y desafĂ­os

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    La presente aportaciĂłn recoge reflexiones y experiencias relacionadas con el trabajo educativo en el territorio de Coyhaique y otros municipios. MĂĄs allĂĄ de las contribuciones que presenta, representa la defensa y reivindicaciĂłn de la participaciĂłn de los municipios en la organizaciĂłn y gestiĂłn del servicio pĂșblico de la educaciĂłn. Si bien es cierto que la educaciĂłn centralizada ha servido durante mucho tiempo a los procesos de generalizaciĂłn de la escolarizaciĂłn, su capacidad de incidencia en la mejora de la calidad educativa es cada vez mĂĄs cuestionada. Y es que no es posible dar las respuestas adecuadas a los variados contextos y situaciones que a menudo se dan dentro de un paĂ­s. La extensiĂłn de los procesos de democratizaciĂłn social y la necesidad de una educaciĂłn respetuosa con los diferentes contextos y mĂĄs atenta a las necesidades de las personas, han promovido los procesos de descentralizaciĂłn y, con ellos, los debates sobre la participaciĂłn municipal en educaciĂłn y la necesidad de la autonomĂ­a institucional. Como reiteran los sucesivos informes PISA, las escuelas funcionan de manera mĂĄs eficiente cuando el nivel de autonomĂ­a es elevado y Ă©ste va acompañado de procesos de rendiciĂłn de cuentas. No se trata de un cambio de modelo sino, creemos, de una necesaria evoluciĂłn del existente. Si queremos que la educaciĂłn tambiĂ©n estĂ© al servicio de las personas, debemos facilitar modelos organizativos que permitan la participaciĂłn de las mismas y de sus entornos prĂłximos. Lo importante es entender que los cambios efectivos son complejos y resultado de sinergias internas y externas, que mĂĄs que excluir a alguien cuentan con los recursos de todos. El presente texto entiende que, a travĂ©s de sus propuestas, ejemplos y valoraciones, puede ayudar al debate establecido. Por una parte, presenta tres aportaciones generales que reflexionan sobre los procesos de cambio, el rol de los municipios y el protagonismo de los profesores, abordando tres niveles de la realidad educativa. Por otra parte, se organizan bloques de aportaciones y experiencias que hacen referencia tanto a las polĂ­ticas y prĂĄcticas organizativas a nivel municipal como a las experiencias relacionadas con la participaciĂłn de los apoderados, la mejora de la calidad o las conexiones con el entorno social. Somos conscientes de que las aportaciones son una pequeña isla dentro de las posibilidades y realidades de la educaciĂłn a nivel de municipios, pero nos parece que sistematizarlas y difundirlas a travĂ©s de un texto puede ser una manera adecuada de impulsar el debate. Esperemos que el ejemplo sea limitado en el futuro

    Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

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    We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z∌0.03z\sim 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z∌0.6z\sim 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July

    Sloan Digital Sky Survey IV: mapping the Milky Way, nearby galaxies, and the distant universe

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    We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July

    Sloan Digital Sky Survey IV : mapping the Milky Way, nearby galaxies, and the distant universe

    Get PDF
    We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z ~ 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z ~ 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
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