234 research outputs found

    An index based load balancer to enhance transactional application servers' QoS

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    The Web is the preferred interface for the new generation of applications. Web services are an ubiquitous concept for both, developers and managers. These Web applications require distribution systems of web requests that allow and support the dynamism of these environments, to provide service availability and resource usage, commonly heterogeneous. Web services provide an entry point to the Web application business logic. Therefore, the design of appropriate load balancing strategies, taking into account the dynamic nature of the application servers' activity, is essential. In this work we present a load balancing policy and its integration inbetween static and dynamic layers of any web application that uses application servers. The strategy gets the status report of each application server, used to later distribute web requests. Results that show how the strategy succeed are presented

    Tracking Traitors in Web Services via Blind Signatures

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    This paper presents a method and its implementation, built on the blind signatures protocol, to trace users sharing their licenses illegally when accessing services provided through Internet (Web services, Streaming, etc). The method devised is able to identify the legitimate user from those users who are illegally accessing services with a shared key. This method is robust when detecting licenses built with no authorization. An enhancement of the protocol to identify the last usage of a certain license is also provided, allowing to detect a traitor when an unauthorized copy of a license is used

    Efficient Implementation on Low-Cost SoC-FPGAs of TLSv1.2 Protocol with ECC_AES Support for Secure IoT Coordinators

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    Security management for IoT applications is a critical research field, especially when taking into account the performance variation over the very different IoT devices. In this paper, we present high-performance client/server coordinators on low-cost SoC-FPGA devices for secure IoT data collection. Security is ensured by using the Transport Layer Security (TLS) protocol based on the TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 cipher suite. The hardware architecture of the proposed coordinators is based on SW/HW co-design, implementing within the hardware accelerator core Elliptic Curve Scalar Multiplication (ECSM), which is the core operation of Elliptic Curve Cryptosystems (ECC). Meanwhile, the control of the overall TLS scheme is performed in software by an ARM Cortex-A9 microprocessor. In fact, the implementation of the ECC accelerator core around an ARM microprocessor allows not only the improvement of ECSM execution but also the performance enhancement of the overall cryptosystem. The integration of the ARM processor enables to exploit the possibility of embedded Linux features for high system flexibility. As a result, the proposed ECC accelerator requires limited area, with only 3395 LUTs on the Zynq device used to perform high-speed, 233-bit ECSMs in 413 µs, with a 50 MHz clock. Moreover, the generation of a 384-bit TLS handshake secret key between client and server coordinators requires 67.5 ms on a low cost Zynq 7Z007S device

    Sistema guiado de localización de aparcamientos para personas discapacitadas

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    Número de publicación: ES2415514 A1 (25.07.2013) También publicado como: ES2415514 B1 (21.05.2014) Número de Solicitud: Consulta de Expedientes OEPM (C.E.O.) P201100282 (04.03.2011)Método para la gestión y control de aparcamientos regulados para discapacitados. La gestión necesaria por parte de los usuarios mediante dispositivos móviles hace necesaria la transferencia de la información por redes General Packet Radio Service (GPRS), Universal Mobile Telecommunication System, High Speed Downlink Packet Access (HSDPA). En el sistema guiado de localización de aparcamiento para personas discapacitadas, el usuario activa en un dispositivo móvil la petición de parking. Remitiendo la identificación del vehículo, posición GPS, -opcionalmente- tiempo estimado de ocupación. Recibiendo en su dispositivo un mapa con aparcamientos codificados en color así como cualquier dato de interés. La información de ocupación está disponible a controladores de tráfico, que reciben en su dispositivo, periódicamente o bajo demanda, información de ocupación de estacionamientos en su zona, de modo que puede controlar el parking (vehículos sin licencia o licencia falsa). Los controladores pueden actualizar la información de ocupación, usando sus dispositivos.Universidad de Almerí

    Assessing different imaging velocimetry techniques to measure shallow runoff velocities during rain events using an urban drainage physical model

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    Although surface velocities are key in the calibration of physically based urban drainage models, the shallow water depths developed during non-extreme precipitation and the potential risks during flood events limit the availability of this type of data in urban catchments. In this context, imaging velocimetry techniques are being investigated as suitable non-intrusive methods to estimate runoff velocities, when the possible influence of rain has yet to be analyzed. This study carried out a comparative assessment of different seeded and unseeded imaging velocimetry techniques based on large-scale particle image velocimetry (LSPIV) and bubble image velocimetry (BIV) through six realistic but laboratory-controlled experiments, in which the runoff generated by three different rain intensities was recorded. First, the use of naturally generated bubbles and water shadows and glares as tracers allows unseeded techniques to measure extremely shallow flows. However, these techniques are more affected by raindrop impacts, which even lead to erroneous velocities in the case of high rain intensities. At the same time, better results were obtained for high intensities and in complex flows with techniques that use artificial particles. Finally, the study highlights the potential of these imaging techniques for measuring surface velocities in real field applications as well as the importance of considering rain properties to interpret and assess the results obtained. The robustness of the techniques for real-life applications yet remains to be proven by means of further studies in non-controlled environments.The project receives funding from the Spanish Ministry of Science and Innovation under POREDRAIN project RTI2018-094217-B-C33 (MINECO/FEDER-EU)

    Proceso para la obtención y purificación de B-Ficoeritrina

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    Número de publicación: ES2197820 A1 (01.01.2004) También publicado como: ES2197820 B1 (01.03.2005) Número de Solicitud: Consulta de Expedientes OEPM (C.E.O.) P200201398 (17.06.2002)Proceso en tres etapas para la obtención y purificación de la proteína B-ficoeritrina procedente de la microalga Porphyridium cruentum caracterizado por su alto rendimiento. La primera etapa consiste en una ruptura celular encaminada a liberar el material citoplasmático mediante un proceso de choque osmótico usando un tapón de ácido acético/acetato sódico. La segunda etapa utiliza un proceso cromatográfico en lecho expandido desarrollado en un columna de absorción rellena con un soporte absorbente iónico denominado Streamline-DEAE. Por último, la tercera etapa es un proceso adicional cromatográfico en columna de intercambio iónico de tipo clásico que utiliza como fase estacionaria un lecho de DEAE-celulosa DE-52.Universidad de Almería. Universidad de Granada. Universidad de Jaé

    CCEDAF: Codificador Combinatorio de Estados para el Diseño de Autómatas Finitos

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    En esta demostración se presenta el funcionamiento de la herramienta software CCEDAF, orientado a alumnos de Laboratorio de Estructura y Tecnología de Computadores, para facilitarles el diseño de autómatas finitos con un menor número de puertas lógicas. La aplicación CCEDAF (Codificador Combinatorio de Estados para el Diseño de Autómatas Finitos) a partir de la tabla de transiciones del sistema digital, asigna todas las posibles combinaciones de codificación de estados para generar diferentes tablas de excitación, y obtener aquellas combinaciones que requieran un menor número de puertas lógicas

    Automatización del problema de asignación de estados en el diseño de sistemas secuenciales síncronos

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    Cuando un alumno se introduce en el mundo del diseño de sistemas secuenciales síncronos se tropieza con dos problemas, minimización y codificación de estados, tanto más significativos cuanto menor número de puertas deseemos. Para la resolución del problema de minimización de estados existe un algoritmo, tan sencillo como largo y tedioso, que esta implementado en la mayoría de los entornos computacionales de diseño digital. Sin embargo, para la resolución del problema de asignación de estados, existen una serie de reglas difíciles de aplicar. Por este motivo se ha programado una herramienta, que a partir de la tabla de transiciones de estados minimizada, permite al alumno obtener los circuitos con menor número de puertas para los distintos tipos de biestables deseados

    Innervation of the Human Cavum Conchae and Auditory Canal: Anatomical Basis for Transcutaneous Auricular Nerve Stimulation

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    The innocuous transcutaneous stimulation of nerves supplying the outer ear has been demonstrated to be as effective as the invasive direct stimulation of the vagus nerve for the treatment of some neurological and nonneurological disturbances. Thus, the precise knowledge of external ear innervation is of maximal interest for the design of transcutaneous auricular nerve stimulation devices. We analyzed eleven outer ears, and the innervation was assessed by Masson’s trichrome staining, immunohistochemistry, or immunofluorescence (neurofilaments, S100 protein, and myelin-basic protein). In both the cavum conchae and the auditory canal, nerve profiles were identified between the cartilage and the skin and out of the cartilage. The density of nerves and of myelinated nerve fibers was higher out of the cartilage and in the auditory canal with respect to the cavum conchae. Moreover, the nerves were more numerous in the superior and posterior-inferior than in the anterior-inferior segments of the auditory canal. The present study established a precise nerve map of the human cavum conchae and the cartilaginous segment of the auditory canal demonstrating regional differences in the pattern of innervation of the human outer ear. These results may provide additional neuroanatomical basis for the accurate design of auricular transcutaneous nerve stimulation devices

    Blockchain from the Perspective of Privacy and Anonymisation: A Systematic Literature Review

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    The research presented aims to investigate the relationship between privacy and anonymisation in blockchain technologies on different fields of application. The study is carried out through a systematic literature review in different databases, obtaining in a first phase of selection 199 publications, of which 28 were selected for data extraction. The results obtained provide a strong relationship between privacy and anonymisation in most of the fields of application of blockchain, as well as a description of the techniques used for this purpose, such as Ring Signature, homomorphic encryption, k-anonymity or data obfuscation. Among the literature researched, some limitations and future lines of research on issues close to blockchain technology in the different fields of application can be detected. As conclusion, we extract the different degrees of application of privacy according to the mechanisms used and different techniques for the implementation of anonymisation, being one of the risks for privacy the traceability of the operations
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