230 research outputs found

    Thermal characterization of urban heat island (UHI) according to urban morphology of Madrid

    Full text link
    Present research is framed within the project MODIFICA (MODelo predictivo - edIFIcios - Isla de Calor Urbana) aimed at developing a predictive model for dwelling energy performance under the urban heat island effect in order to implement it in the evaluation of real energy demand and consumption of dwellings as well as in the selection of energy retrofitting strategies. It is funded by Programa de I+D+i orientada a los retos de la sociedad 'Retos Investigación' 2013. The scope of our predictive model is defined by the heat island effect (UHI) of urban structures that compose the city of Madrid. In particular, we focus on the homogeneous areas for urban structures with the same urban and building characteristics. Data sources for the definition of such homogeneous areas were provided by previous research on the UHI of Madrid. The objective is to establish a critical analysis of climate records used for energy simulation tools, which data come from weather stations placed in decontextualized areas from the usual urban reality, where the thermal conditions differs by up to 6ºC. In this way, we intend to develop a new predictive model for the consumption and demand in buildings depending on their location, the urban structure and the associated UHI, improving the future energy rehabilitation intervention

    Towards a dynamic model for the Urban Heat Island of Madrid

    Get PDF
    Present research is framed within the project MODIFICA (MODelo predictivo - edIFIcios - Isla de Calor urbanA) aimed at developing a predictive model for dwelling energy performance under the urban heat island effect in order to implement it in the evaluation of real energy demand and consumption of dwellings as well as in the selection of energy retrofitting strategies. It is funded by Programa de I+D+i orientada a los retos de la sociedad 'Retos Investigación' 2013. Despite great advances on building energy performance have been achieved during the last years, available climate data is derived from weather stations placed in the outskirts of the city. Hence, urban heat island effect is not considered in energy simulations, which implies an important lack of accuracy. Since 1980's several international studies have been conducted on the urban heat island (UHI) phenomena, which modifies the atmospheric conditions of the urban centres due to urban agglomeration [1][2][3][4]. In the particular case of Madrid, multiple maps haven been generated using different methodologies during the last two decades [5][6][7]. These maps allow us to study the UHI phenomena from a wide perspective, offering however an static representation of it. Consequently a dynamic model for Madrid UHI is proposed, in order to evaluate it in a continuous way, and to be able to integrate it in building energy simulations

    Personal IoT Privacy Control at the Edge.

    Get PDF
    Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/23052?template=rome

    A survey on the (in)security of trusted execution environments

    Get PDF
    As the number of security and privacy attacks continue to grow around the world, there is an ever increasing need to protect our personal devices. As a matter of fact, more and more manufactures are relying on Trusted Execution Environments (TEEs) to shield their devices. In particular, ARM TrustZone (TZ) is being widely used in numerous embedded devices, especially smartphones, and this technology is the basis for secure solutions both in industry and academia. However, as shown in this paper, TEE is not bullet-proof and it has been successfully attacked numerous times and in very different ways. To raise awareness among potential stakeholders interested in this technology, this paper provides an extensive analysis and categorization of existing vulnerabilities in TEEs and highlights the design flaws that led to them. The presented vulnerabilities, which are not only extracted from existing literature but also from publicly available exploits and databases, are accompanied by some effective countermeasures to reduce the likelihood of new attacks. The paper ends with some appealing challenges and open issues.Funding for open access charge: Universidad de Málaga / CBUA This work has been partially supported by the Spanish Ministry of Science and Innovation through the SecureEDGE project (PID2019-110565RB-I00), and by the by the Andalusian FEDER 2014–2020 Program through the SAVE project (PY18-3724)

    Edge-Assisted Vehicular Networks Security.

    Get PDF
    Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/29486?template=romeoEdge Computing paradigms are expected to solve some major problems affecting current application scenarios that rely on Cloud computing resources to operate. These novel paradigms will bring computational resources closer to the users and by doing so they will not only reduce network latency and bandwidth utilization but will also introduce some attractive context-awareness features to these systems. In this paper we show how the enticing features introduced by Edge Computing paradigms can be exploited to improve security and privacy in the critical scenario of vehicular networks (VN), especially existing authentication and revocation issues. In particular, we analyze the security challenges in VN and describe three deployment models for vehicular edge computing, which refrain from using vehicular-to-vehicular communications. The result is that the burden imposed to vehicles is considerably reduced without sacrificing the security or functional features expected in vehicular scenarios

    Immune system for the internet of things using edge technologies

    Get PDF
    The Internet of Things (IoT) and Edge Computing are starting to go hand in hand. By providing cloud services close to end-users, edge paradigms enhance the functionality of IoT deployments, and facilitate the creation of novel services such as augmented systems. Furthermore, the very nature of these paradigms also enables the creation of a proactive de- fense architecture, an immune system, which allows authorized immune cells (e.g., virtual machines) to traverse edge nodes and analyze the security and consistency of the underlying IoT infrastructure. In this article, we analyze the requirements for the development of an immune system for the IoT, and propose a security architecture that satisfies these requirements. We also describe how such a system can be instantiated in Edge Computing infrastructures using existing technologies. Finally, we explore the potential application of immune systems to other scenarios and purposes

    Hacia un modelo dinámico para la isla de calor urbana de Madrid = Towards a Dynamic Model for the Urban Heat Island of Madrid

    Get PDF
    Esta investigación se enmarca dentro del proyecto MODIFICA (modelo predictivo - Edificios - Isla de Calor Urbano), financiado por el Programa de I + D + i Orientada a los Retos de la sociedad 'Retos Investigación' de 2013. Está dirigido a desarrollar un modelo predictivo de eficiencia energética para viviendas, bajo el efecto de isla de calor urbano (AUS) con el fin de ponerla en práctica en la evaluación de la demanda de energía real y el consumo en las viviendas. A pesar de los grandes avances que se han logrado durante los últimos años en el rendimiento energético de edificios, los archivos de tiempo utilizados en la construcción de simulaciones de energía se derivan generalmente de estaciones meteorológicas situadas en las afueras de la ciudad. Por lo tanto, el efecto de la Isla de Calor Urbano (ICU) no se considera en estos cálculos, lo que implica una importante falta de precisión. Centrado en explorar cómo incluir los fenómenos ICU, el presente trabajo recopila y analiza la dinámica por hora de la temperatura en diferentes lugares dentro de la ciudad de Madrid. Abstract This research is framed within the project MODIFICA (Predictive model - Buildings - Urban Heat Island), funded by Programa de I+D+i orientada a los retos de la sociedad 'Retos Investigación' 2013. It is aimed at developing a predictive model for dwelling energy performance under the Urban Heat Island (UHI) effect in order to implement it in the evaluation of real energy demand and consumption in dwellings. Despite great advances on building energy performance have been achieved during the last years, weather files used in building energy simulations are usually derived from weather stations placed in the outskirts of the city. Hence, Urban Heat Island (UHI) effect is not considered in this calculations, which implies an important lack of accuracy. Focused on exploring how to include the UHI phenomena, the present paper compiles and analyses the hourly dynamics of temperature in different locations within the city of Madrid

    Dissociable Effects of Executive Load on Perceived Exertion and Emotional Valence during Submaximal Cycling

    Get PDF
    Endurance physical exercise is accompanied by subjective perceptions of exertion (reported perceived exertion, RPE), emotional valence, and arousal. These constructs have been hypothesized to serve as the basis for the exerciser to make decisions regarding when to stop, how to regulate pace, and whether or not to exercise again. In dual physical-cognitive tasks, the mental (executive) workload generated by the cognitive task has been shown to influence these perceptions, in ways that could also influence exercise-related decisions. In the present work, we intend to replicate and extend previous findings that manipulating the amount of executive load imposed by a mental task, performed concomitantly with a submaximal cycling session, influenced emotional states but not perceived exertion. Participants (experienced triathletes) were asked to perform a submaximal cycling task in two conditions with different executive demands (a two-back version of the n-back task vs. oddball) but equated in external physical load. Results showed that the higher executive load condition elicited more arousal and less positive valence than the lower load condition. However, both conditions did not differ in RPE. This experimental dissociation suggests that perceived exertion and its emotional correlates are not interchangeable, which opens the possibility that they could play different roles in exercise-related decision-making.Spanish Ministry of Economy and Competitiveness (Secretaria de Estado de Investigacion, Desarrollo e Innovacion; Convocatoria 2017 de Proyectos I + D, de Retos a la Sociedad; Spain) DEP2017-89879-RSpanish Government (Ministerio de Economia y Competitividad, Secretaria de Estado de Investigacion, Desarrollo e Innovacion; Convocatoria 2017 de Proyectos I + D de Excelencia, Spain - Fondo Europeo de Desarrollo Regional, FEDER, European Union) PSI2017-85488-

    La calidad de las pastas frente al arroz es determinante en el control del hambre y el apetito: Estudio comparativo de pasta y arroz

    Get PDF
    Introduction: The aim of the present study was to evaluate if the pasta quality is decisive in controlling hunger and satiety compared with rice.Material and methods: n=16 (8 men, 8 women). The effect on appetite and satiety of two different-quality pastas and also rice was determined by repeated measuring. Subjects came on fasting and were evaluated at different times after the intake of product under investigation for 240 min, eaten an ad libitum buffet and were evaluated again at minute 270. Aspects related to satiety (hunger, satiety, fullness, and desire to eat) were evaluated by visual analog scale (VAS), overall appetite score (OAS), area under curve (AUC) and satiety quotient (SQ).Results: The OAS reported by volunteers prior to the intake of products under investigation did not differ significantly, so baseline parameters did not bias later measurements. AUC after 60 minutes was higher after the intake of rice (2355 ±1556%/min) compared with both types of pasta. On the other hand, similar values were obtained between the two types of pasta (pasta A = 1808 ± 1329 % /min; pasta B = 1,774 ± 1,370%/min). Further, AUC reported by volunteers after 240 minutes was higher after the intake of rice (12,424 ± 6,187%/min) compared with both types of pastas (pasta A = 10,292 ± 5,410%/min; pasta B = 9,976 ± 5,589%/min). In addition, SQ was lower for rice (1.90 ± 4.29%/kcal) than for both pastas (pasta A = 4.73 ± 4.95%/kcal; pasta B = 4.40 ± 5.14%/kcal).Conclusions: Both varieties of pasta showed higher satiety results than rice, with no significant difference between them. In addition, the difference between rice and pasta was greater within 60 minutes after ingestion.Introducción: El objetivo del presente estudio fue evaluar si la calidad de la pasta es decisiva para controlar el hambre y la saciedad en comparación con el arroz.Material y métodos: n = 16 (8 hombres, 8 mujeres). El efecto sobre el apetito y la saciedad de dos pastas de diferente calidad y también del arroz se determinó mediante mediciones repetidas. Los sujetos entraron en ayunas y fueron evaluados en diferentes momentos después de la ingesta del producto investigado durante 240 minutos, comieron un bufet ad libitum y fueron evaluados nuevamente en el minuto 270. Aspectos relacionados con la saciedad (hambre, saciedad, saciedad y deseo de comer) fueron evaluados por escala visual analógica (VAS), puntaje global de apetito (OAS), área bajo curva (AUC) y cociente de saciedad (SQ).Resultados: La OEA informada por los voluntarios antes de la ingesta de productos bajo investigación no difirió significativamente, por lo que los parámetros de referencia no sesgaron las mediciones posteriores. El AUC después de 60 minutos fue mayor después de la ingesta de arroz (2.355 ± 1.556%/min) en comparación con ambos tipos de pasta. Por otro lado, se obtuvieron valores similares entre los dos tipos de pasta (pasta A = 1.808 ± 1.329%/min; pasta B = 1.774 ± 1.370%/min). Además, el AUC informado por los voluntarios después de 240 minutos fue mayor después de la ingesta de arroz (12.424 ± 6.187%/min) en comparación con ambos tipos de pastas (pasta A = 10.292 ± 5.410%/min; pasta B = 9.976 ± 5.589%/min). Además, la SQ fue menor para el arroz (1,90 ± 4,29%/kcal) que para ambas pastas (pasta A = 4,73 ± 4,95%/kcal; pasta B = 4,40 ± 5,14%/kcal).Conclusiones: Ambas variedades de pasta mostraron resultados de saciedad más altos que el arroz, sin diferencias significativas entre ellos. Además, la diferencia entre arroz y pasta fue mayor dentro de los 60 minutos posteriores a la ingestión

    FPGA acceleration using high-level languages of a Monte-Carlo method for pricing complex options

    Full text link
    This is the author’s version of a work that was accepted for publication in Journal of Systems Architecture. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Systems Architecture, 59, 3 (2013) DOI: 10.1016/j.sysarc.2013.01.004In this paper we present an FPGA implementation of a Monte-Carlo method for pricing Asian options using Impulse C and floating-point arithmetic. In an Altera Stratix-V FPGA, a 149x speedup factor was obtained against an OpenMP-based solution in a 4-core Intel Core i7 processor. This speedup is comparable to that reported in the literature using a classic HDL-based methodology, but the development time is significantly reduced. Additionally, the use of a HLL-based methodology allowed us to implement a high-quality Gaussian random number generator, which produces more precise results than those obtained with the simple generators usually present in HDL-based designs
    corecore