2,095 research outputs found

    Servicios avanzados de telefonía IP mediante SIP

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    La telefonía IP es una evolución de la telefonía convencional, que funciona mediante conmutación de circuitos, hacia conmutación de paquetes, un tipo de conmutación, en principio no pensada para este fin y que gracias al crecimiento de la popularidad de las redes de acceso de banda ancha aparece como una realidad viable. SIP es el protocolo de señalización utilizado en este tipo de telefonía. La incorporación de servidores de aplicaciones SIP permite la implementación de servicios avanzados en el marco de la telefonía IP que incrementan las posibilidades que ofrece la telefonía convencional. Para disponer de un servidor de aplicaciones dentro de un entorno hay que definir los elementos básicos de la arquitectura a la que pertenece tales como la integración con otros servidores de aplicaciones, con servidores SIP, con puertas de enlace, etc. La interacción de todos estos elementos se muestra en la explicación de un ejemplo real.Peer Reviewe

    Physical Activity, Exercise and Sport Programs as Effective Therapeutic Tools in Psychosocial Rehabilitation

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    People with severe psychosocial disabilities have a 20-years shorter lifespan due to chronic somatic comorbidities and the long-term consequences of the side-effects of antipsychotic drugs. They often are sedentary and show lower levels of physical activity, factors which can contribute to their shorter lifespan, because of the greater cardiovascular risk. An increasing amount of evidence, including clinical trials, pointed out that sport, physical activity and structured exercise programs improve physical and psychological wellbeing of people with psychosocial disabilities, playing also an important role against their social isolation and self-stigma. The NICE and APA guidelines include exercise and physical activity for the management of depressive symptoms. Safe and effective programs require multidisciplinary teams that should always include mental health professionals, able to recognize the psychosocial needs, the impact of symptomatology, the role of secondary effects of psychotropic medication, the effect of previous exercise history, the lack of motivation, the inexperience with effort intensity and the frustration of people with psychosocial disabilities

    Desenvolupament d'un projecte de rec artificial per a un circuït de proves de motor

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    Aquest projecte tracta el disseny de les instal·lacions necessàries per implantar un sistema de rec artificial sobre la pista d’un circuit de carreres, en concret el Circuit de Barcelona-Catalunya. Es dissenya la instal·lació hidràulica de rec, es distribueixen dipòsits, s'amplia la xarxa de drenatge existent i es determinen les dimensions d’una depuradora pel tractament de l’aigua recollida tant de la pluja com del propi rec. Un dels criteris més importants és la recuperació de la màxima quantitat possible d’aigua utilitzada. Es realitza el càlcul i justificació de les dimensions de les instal·lacions necessàries i s’elaboren els diferents plànols que defineixen completament i sense ambigüitat les obres i modificacions a realitzar en el circuit. A més, el projecte compta amb documents típics d’un projecte executiu com el plec de condicions i el pressupost, on es realitza una anàlisi dels costos i el període de retorn de la inversió. Es duu a terme, també, un estudi de la portabilitat del projecte a d’altres latituds del globus, permetent una aproximació del cost total de les instal·lacions en dependència amb la localització del circuit. El resultat és un projecte complet capaç de caracteritzar tots els aspectes i detalls esperats d'un projecte d’instal·lacions, preparat per la realització de les obres projectades per complir els principals objectius

    Application layer multicast algorithm

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    This paper presents a multicast algorithm, called MSM-s, for point-to-multipoint transmissions. The algorithm, which has complexity O(n2) in respect of the number n of nodes, is easy to implement and can actually be applied in other point-to multipoint systems such as distributed computing. We analyze the algorithm and we provide some upper and lower bounds for the multicast time delay.Peer Reviewe

    Modulation of Sleep Homeostasis by Corticotropin Releasing Hormone in REM Sleep-Deprived Rats

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    Studies have shown that sleep recovery following different protocols of forced waking varies according to the level of stress inherent to each method. Sleep deprivation activates the hypothalamic-pituitary-adrenal axis and increased corticotropin-releasing hormone (CRH) impairs sleep. The purpose of the present study was to evaluate how manipulations of the CRH system during the sleep deprivation period interferes with subsequent sleep rebound. Throughout 96 hours of sleep deprivation, separate groups of rats were treated i.c.v. with vehicle, CRH or with alphahelical CRH9−41, a CRH receptor blocker, twice/day, at 07:00 h and 19:00 h. Both treatments impaired sleep homeostasis, especially in regards to length of rapid eye movement sleep (REM) and theta/delta ratio and induced a later decrease in NREM and REM sleep and increased waking bouts. These changes suggest that activation of the CRH system impact negatively on the homeostatic sleep response to prolonged forced waking. These results indicate that indeed, activation of the HPA axis—at least at the hypothalamic level—is capable to reduce the sleep rebound induced by sleep deprivation

    Growth and social entrepreneurs: the challenge of conciliating economic and social values

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    AbstractPurpose – This research aimed to describe the phenomenon of the growth of enterprises in the vision of socialentrepreneurs.Design/methodology/approach –This is a qualitative study developed joining eight social entrepreneurs infour organizations, two cooperatives and two associations. Data were obtained in semi structured interviews.Data were analyzed with interpretativist and the classical content analysis.Findings – The main findings indicated the growth phenomenon presented in five categories: growthintentions, growth meanings, support of other organizations and participation in networks, strategies anddifficulties. The results of the research have shown that the growth for the social entrepreneurs is a collectivephenomenon, characterized by search of economic value and empowerment.Research limitations/implications – The main limitation of the research was study only two types oforganizations, one garbage cooperative and two association.Practical implications – The results can help managers of social incubators and stakeholders because it wasevidenced the efforts and difficulties that social entrepreneurs face to survive and to search growth.Social implications – Our findings may contribute to the formulation of public policies oriented to socialentrepreneurs.Originality/value – This paper presents the first theoretical contribution about the growth in a specificcontext, the context of social entrepreneurs &nbsp

    E-Sports: a legitimate sport?

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    Currently, our society is facing an increase in the levels of physical inactivity in the world population, especially an increase in screen time, causing potential adverse effects in the short and long term to health (Stiglic & Viner, 2019; Domingues‐Montanari, 2017). Several institutions, such as the World Health Organization (WHO), American College of Sports Medicine (ACSM), and National Institute for Health and Care Excellence (NICE), recognize the importance of physical exercise as a potential tool against the risks associated with sedentary behavior (Piercy et al., 2018). And within that context, a question must be asked; can screen time be considered time spent on sports?(…)info:eu-repo/semantics/publishedVersio

    Degenerate epitaxy-driven defects in monolayer silicon oxide onto ruthenium

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    The structure of the ultimately-thin crystalline allotrope of silicon oxide, prepared onto a ruthenium surface, is unveiled down to atomic scale with chemical sensitivity, thanks to high resolution scanning tunneling microscopy and first principle calculations. An ordered oxygen lattice is imaged which coexists with the two-dimensional monolayer oxide. This coexistence signals a displacive transformation from an oxygen reconstructed-Ru(0001) to silicon oxide, along which latterally-shifted domains form, each with equivalent and degenerate epitaxial relationships with the substrate. The unavoidable character of defects at boundaries between these domains appeals for the development of alternative methods capable of producing single-crystalline two-dimensional oxides

    Experimental modal analysis of an aircraft wing prototype for SAE Aerodesign Competition

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    This work presents an experimental modal analysis of an aircraft wing prototype, designed by the Aerodesign team of the University of Brasilia, and performs a ground vibration testing of the prototype. The dynamic response data were acquired using the software LabVIEW, and the modal parameters were identified through the EasyMod toolbox. The modal parameters are characterised for the first seven vibration modes of the structure, with the firsts two being suspension modes of vibration. The effect of small changes in the experimental procedure on the identified modal parameters is discussed. It was observed that the use of an excitation signal as a logarithmic sine sweep and with a frequency range of excitation between 2 to 150 Hz resulted in less noise and more accurate measurement of the structure’s response. Results for different modal identification methods were verified using the Modal Assurance Criterion (MAC), and good correlation was achievedEste trabajo presenta el análisis modal experimental de un prototipo de ala de avión diseñado por el equipo de Aerodesign de la Universidad de Brasilia, que realiza una prueba de vibración del suelo en el prototipo. Los datos de respuesta dinámica se obtienen con el software LabVIEW y los parámetros modales identificados a través de la caja de herramientas EasyMod. Los parámetros modales se caracterizan por los primeros siete modos de vibración de la estructura. Se discute el efecto de pequeños cambios en el procedimiento experimental sobre los parámetros modales identificados. Se observó que el uso de la señal de excitación como barrido sinusoidal logarítmico y con un rango de frecuencia de excitación entre 2 y 150 Hz dio como resultado menos ruido y una medición más precisa de la respuesta de la estructura. Los resultados para diferentes métodos de identificación modal se verificaron utilizando el Criterio de Garantía Modal (MAC), y se logró una buena correlació
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