625 research outputs found

    Lightweigth Adaptive fault-tolerant data storage system (AFTSYS)

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    Research group ARCOS of Universidad Carlos III de Madrid (Spain) have been working on flexible and adaptive data storage systems for several years. The storage systems developed are featured by software governance, making them portable across different hardware storage resources, and their dynamic adaptativy to the different circumstances of computer systems following the autonomic system paradigm. They also allow getting high performance storage by using data distribution or striping across multiple devices. One of the group’s technologies y the AFTSYS system. A fault-tolerant storage system for persistent distributed objects, user configurable and adaptive to system behaviour

    Almacenamiento de datos ligero adaptativo y tolerante a fallos (AFTSYS)

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    El grupo de investigación ARCOS de la Universidad Carlos III de Madrid (España), lleva varios años trabajando en sistemas de almacenamiento de datos flexibles y adaptativos. Sus sistemas de almacenamiento se caracterizan porque se gobiernan mediante software, lo que permite implementarlos sobre distintas plataformas hardware asegurando su portabilidad, se adaptan dinámicamente a las circunstancias de los sistemas siguiendo el paradigma de los sistemas autónomos y permiten obtener partido de sistemas con almacenamiento de datos distribuidos o repartidos entre múltiples dispositivos. Una de las tecnologías del grupo es el sistema AFTSYS. Un sistema de almacenamiento tolerante a fallos a nivel de objetos persistentes distribuidos, configurable por el usuario y adaptable al comportamiento del sistema

    Creación automática de aplicaciones seguras para wireless sensors networks usando MDA

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    El grupo de investigación ARCOS de la Universidad Carlos III de Madrid (España), lleva varios años trabajando en sistemas de almacenamiento de datos flexibles y adaptativos. Sus sistemas de almacenamiento se caracterizan porque se gobiernan mediante software, lo que permite implementarlos sobre distintas plataformas hardware asegurando su portabilidad, se adaptan dinámicamente a las circunstancias de los sistemas siguiendo el paradigma de los sistemas autónomos y permiten obtener partido de sistemas con almacenamiento de datos distribuidos o repartidos entre múltiples dispositivos. Una de las tecnologías del grupo es el sistema AFTSYS. Un sistema de almacenamiento tolerante a fallos a nivel de objetos persistentes distribuidos, configurable por el usuario y adaptable al comportamiento del sistema

    Calculation of the Risk of Lawsuits over Construction Flaws in Flat Roofs

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    In order to achieve sustainability objectives in the use of a building, its elements’ operating problems should be minimized. From this premise, a total of 497 cases related to construction flaws in flat roofs were analyzed in this research. A matrix was developed indicating the risk of lawsuits by owners according to the degree of nuisance resulting from the construction flaws studied, their technical importance, and the type of pathological origin. Based on these factors, it is possible to predict a greater or lesser probability of an owner filing a lawsuit—risk factor (F). A wide range was found for this probability, with the largest value being 865 times greater than the smallest value. The value of F was divided into 5 categories to classify the diverse results obtained and determine the number of cases and interrelations ascribed to each category. Additionally, the level of presence of said cases was calculated through the analysis of 3 di erent demographic aspects, it being noted that a greater purchasing power and a higher concentration of urban population lead to more stringent requirements and, subsequently, to a greater number of lawsuits. With all these results, building quality can be improved while resulting in greater constructive-financial sustainability and in a reduction of the economic resources required of society (fewer lawsuits and associated human resources)

    Optimal railway infrastructure maintenance and repair policies to manage risk under uncertainty with adaptive control

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    The aim of this paper is to apply two adaptive control formulations under uncertainty, say open-loop and closed-loop, to the process of developing maintenance and repair policies for railway infrastructures. To establish the optimal maintenance and repair policies for railway lines, we use a previous design of risk model based on two factors: the criticality and the deterioration ratios of the facilities. Thus, our theory benefits from the Reliability Centered Management methodology application, but it also explicitly models uncertainty in characterizing a facility deterioration rate to decide the optimal policy to maintain the railway infrastructures. This may be the major contribution of this work. To verify the models presented, a computation study has been developed and tested for a real scenario: the railway line Villalba-Cercedilla in Madrid (Spain). Our results demonstrate again that applying any adaptive formulation, the cost of the railway lines maintenance shown is decreased. Moreover applying a Closed Loop Formulation the cost associated to the risk takes smaller values (40% less cost for the same risk than the deterministic approach), but with an Open Loop formulation the generated risk in the railway line is also smaller

    Quality of service optimization in solar cells-based energy harvesting wireless sensor networks

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    In energy harvesting wireless sensor networks, the sensors are able to harvest energy from the environment to recharge their batteries and thus prolong indefinitely their activities. Widely used energy harvesting systems are based on solar cells, which are predictable (i.e., their energy production can be predicted in advance). However, since the energy production of solar cells is not constant during the day, and it is null at night time, these systems require algorithms able to balance the energy consumption and production of the sensors. In this framework, we approach the design of a scheduling algorithm for the sensors that selects among a set of available tasks for the sensors (each assigned with a given quality of service), in order to keeping the sensors energy neutral, i.e., the energy produced during a day exceeds the energy consumed in the same time frame, while improving the overall quality of service. The algorithm solves an optimization problem by using a greedy approach that can be easily implemented on low-power sensors. The simulation results demonstrate that our approach is able to improve the quality of the overall scheduling plan of all networked sensors and that it actually maintains them energy neutral

    Analysis and optimization of the efficiency of induction heating applications with litz-wire planar and solenoidal coils

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    Optimization of the efficiency of an induction heating application is essential in order to improve both reliability and performance. For this purpose, multi-stranded cables with litz structure are often used in induction heating applications. This paper presents an analysis and optimization of the efficiency of induction heating systems focusing on the optimal copper volume of the winding with respect to different constraints. The analysis is based on the concept of a one-strand one-turn coil, which captures the dissipative effects of an induction heating system and reduces the number of variables of the analysis. An expression for the efficiency of the induction heating system is derived. It is found that, with the geometry and the other parameters of the system fixed, efficiency depends on the copper volume of the windings. In order to use this result to optimize the efficiency of an application, volume restrictions, the packing factor and the window utilization factor are also considered. The optimum frequency for an induction heating system is also studied in this work. An experimental verification for both planar and solenoidal cases is also presented

    M-PLAT: Multi-Programming Language Adaptive Tutor

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    Combining malleability and I/O control mechanisms to enhance the execution of multiple applications

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    This work presents a common framework that integrates CLARISSE, a cross-layer runtime for the I/O software stack, and FlexMPI, a runtime that provides dynamic load balancing and malleability capabilities for MPI applications. This integration is performed both at application level, as libraries executed within the application, as well as at central-controller level, as external components that manage the execution of different applications. We show that a cooperation between both runtimes provides important benefits for overall system performance: first, by means of monitoring, the CPU, communication and I/O performances of all executing applications are collected, providing a holistic view of the complete platform utilization. Secondly, we introduce a coordinated way of using CLARISSE and FlexMPI control mechanisms, based on two different optimization strategies, with the aim of improving both the application I/O and overall system performance. Finally, we present a detailed description of this proposal, as well as an empirical evaluation of the framework on a cluster showing significant performance improvements at both application and wide-platform levels. We demonstrate that with this proposal the overall I/O time of an application can be reduced by up to 49% and the aggregated FLOPS of all running applications can be increased by 10% with respect to the baseline case. (C) 2018 Elsevier Inc. All rights reserved.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work has been partially supported by the Spanish “Ministerio de Economia y Competitividad” under the project grant TIN2016-79637-P “Towards Unification of HPC and Big Data paradigms” and EU under the COST Program Action IC1305, Network for Sustainable Ultrascale Computing (NESUS)

    Optimización de carga de datos en un banco de pruebas de aviónica

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    Ponencias de las Decimocuartas Jornadas de Paralelismo de la Universidad Carlos III de Madrid celebradas el 15, 16 y 17 de septiembre de 2003 en Leganés, MadridEste artículo presenta las técnicas de optimización utilizadas para acelerar la carga de definiciones de señales de un banco de pruebas de aviónica. La carga de datos en formato XML puede presentar problemas de rendimiento cuando se trata de grandes volumenes de datos. Bajo esas condiciones, es necesario buscar alternativas que permitan cargar los datos de forma más eficiente, sin imponer restricciones a los generadores de los datos utilizados como entrada. El artículo analiza posibles optimizaciones y valora las ventajas e inconvenientes de cada solución.Publicad
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