931 resultados para Receiver


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Contribuir a la fundamentación teórica de la prescripción individualizada de protocolos de entrenamiento interválico controlado mediante frecuencia cardíaca. Analizar los cambios en el tiempo de pausa y su relación con los cambios de las respuestas fisiológicas a un programa mixto de entrenamiento en sedentarios basado en protocolos interválicos prescritos mediante la frecuencia cardíaca según criterios metodológicos previamente determinados.. Muestra 1: compuesta por 12 atletas en activo en pruebas de medio fondo o fondo, mayores de 17 años con dos o más años de experiencia en competición federada, que ejecutaban habitualmente entrenamiento interválico con repeticiones de 400 mts y cuyo entrenamiento semanal en el mes previo a las pruebas superó los 65 kilómetros semanales. Muestra 2: compuesta por 11 personas de actividad sedentaria, sin antecedentes de actividad física regular, ya fuese de forma competitiva o recreativa.. La investigación se divide en dos bloques, en el primero de ellos se define el marco conceptual de la investigación, revisandose las bases y principios del entrenamiento y la capacidad aeróbica así como del gasto energético y su medición. En el segundo bloque, de corte experimental, se definen las siguientes hipótesis: 1/ la frecuencia cardíaca es un parámetro útil para prescribir y controlar la intensidad y la pausa de los entrenamientos interválicos en atletas y sedentarios sanos. 2/ Un programa de entrenamiento mixto con entrenamientos interválicos controlados mediante la frecuencia cardíaca y con intensidades submáximas superiores al umbral ventilatorio es útil (eficaz y adherente) para mejorar la tolerancia al ejercicio en sedentarios sanos. Se definen 2 protocolos de entrenamiento diferenciados por el criterio de determinación de la pausa para las dos muestras y se analizan los resultados obtenidos. . Pruebas de Conconi. Pulsómetro Sport Tester 3000 receiver.SPSS PC+. Índice de Correlación de Pearson. Pruebas de concordancia de Kendall. Pruebas de Kolmogorov-Smirnov. Análisis multifactorial de la varianza (MANOVA). Los resultados parecen confirmar las dos hipótesis propuestas. Las características de un entrenamiento interválico cambian significativamente al variar el criterio de determinación de la pausa mediante un tiempo fijo o hasta recuperar una frecuencia cardíaca predeterminada. La velocidad de recuperación de la frecuencia cardíaca aumenta significativamente con el entrenamiento en sedentarios sanos. Para prescribir y controlar la intensidad de las repeticiones en los entrenamientos interválicos se sugiere: ejecución de las repeticiones a un nivel de esfuerzo constante, uso cotidiano de R10 por la facilidad de su medición. En relación a las características de las pausas se recomienda: reducir drásticamente la intensidad del ejercicio hasta la recuperación de un determinado ritmo cardíaco. Si la actividad durante la pausa es pasiva, se aconseja descansar hasta recuperar una FC ligeramente inferior la FC del umbral aeróbico..

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Este trabalho de investigação consiste num estudo empírico sobre uma nova ciência - a Biblioterapia, e a situação mais específica, a sua aplicação em contexto prisional. Para alcançar este objetivo formulámos a seguinte hipótese: “o livro exerce sobre as pessoas em geral e, de uma forma mais particular, sobre indivíduos em contexto de detenção institucional uma função terapêutica”. A metodologia adotada para esta investigação assenta essencialmente em fontes documentais textuais e digitais, sobre autores especialistas na matéria, que de uma forma mais precisa se identificam e citam especificamente no capítulo referente à revisão da literatura. Para atingir o nosso propósito começámos por definir os conceitos de leitura, de leitura terapêutica, de fenomenologia da linguagem, de terapia e de diálogo assim como procurámos saber quais os fundamentos filosóficos e os componentes biblioterapêuticos, público-alvo e áreas com maiores potencialidades de aplicação, benefícios e limitações que norteiam à aplicação da Biblioterapia, nomeadamente, para fins de desenvolvimento pessoal e de alterações comportamentais. Fez-se igualmente uma análise da evolução do conceito, desde Aristóteles até aos nossos dias. Só com o conhecimento efetivo desta realidade seria possível prosseguir o nosso objeto de estudo. Entendemos ainda ser importante perceber qual é a situação da leitura em Portugal e as políticas desenvolvidas nesta área pelo Estado, para promover a leitura junto dos estudantes e da população em geral. Apenas assente nestas duas realidades que se entrecruzam, no processo de leitor/livro é possível identificar e relacionar esta problemática em estudo. Constatamos a existência de dois tipos de Biblioterapia, a Biblioterapia-arte e a Biblioterapia-ciência, identificando algumas das suas características, principalmente o que as aproxima e o que as separa. Apresentamos um exemplo de uma área reconhecidamente bem sucedida na aplicação da Biblioterapia não-clínica, em instituições prisionais, efetuando uma abordagem às questões mais pertinentes neste campo: os seus aspetos institucionais, os psicossociais e os de reinserção social. Considerámos ainda as recomendações da IFLA para este setor populacional – Guidelines for Library Services to Prisoners. Ao longo do trabalho e de uma forma transversal realçamos as interrelações biblioterapêuticas entre pacientes, bibliotecários e outros intervenientes no processo biblioterapêutico, tais como médicos e orientadores de leitura. Finalizamos o trabalho concluindo que a prática de leitura de temas específicos, em qualquer campo de atuação e sob orientação de um elemento profissional com conhecimentos aprofundados tanto em relação às personalidades e problemas dos destinatários como aos materiais que tem à sua disposição – o livro, em sentido lato - pode efetivamente desencadear benefícios terapêuticos nos leitores.

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The long-term stability, high accuracy, all-weather capability, high vertical resolution, and global coverage of Global Navigation Satellite System (GNSS) radio occultation (RO) suggests it as a promising tool for global monitoring of atmospheric temperature change. With the aim to investigate and quantify how well a GNSS RO observing system is able to detect climate trends, we are currently performing an (climate) observing system simulation experiment over the 25-year period 2001 to 2025, which involves quasi-realistic modeling of the neutral atmosphere and the ionosphere. We carried out two climate simulations with the general circulation model MAECHAM5 (Middle Atmosphere European Centre/Hamburg Model Version 5) of the MPI-M Hamburg, covering the period 2001–2025: One control run with natural variability only and one run also including anthropogenic forcings due to greenhouse gases, sulfate aerosols, and tropospheric ozone. On the basis of this, we perform quasi-realistic simulations of RO observables for a small GNSS receiver constellation (six satellites), state-of-the-art data processing for atmospheric profiles retrieval, and a statistical analysis of temperature trends in both the “observed” climatology and the “true” climatology. Here we describe the setup of the experiment and results from a test bed study conducted to obtain a basic set of realistic estimates of observational errors (instrument- and retrieval processing-related errors) and sampling errors (due to spatial-temporal undersampling). The test bed results, obtained for a typical summer season and compared to the climatic 2001–2025 trends from the MAECHAM5 simulation including anthropogenic forcing, were found encouraging for performing the full 25-year experiment. They indicated that observational and sampling errors (both contributing about 0.2 K) are consistent with recent estimates of these errors from real RO data and that they should be sufficiently small for monitoring expected temperature trends in the global atmosphere over the next 10 to 20 years in most regions of the upper troposphere and lower stratosphere (UTLS). Inspection of the MAECHAM5 trends in different RO-accessible atmospheric parameters (microwave refractivity and pressure/geopotential height in addition to temperature) indicates complementary climate change sensitivity in different regions of the UTLS so that optimized climate monitoring shall combine information from all climatic key variables retrievable from GNSS RO data.

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Structured data represented in the form of graphs arises in several fields of the science and the growing amount of available data makes distributed graph mining techniques particularly relevant. In this paper, we present a distributed approach to the frequent subgraph mining problem to discover interesting patterns in molecular compounds. The problem is characterized by a highly irregular search tree, whereby no reliable workload prediction is available. We describe the three main aspects of the proposed distributed algorithm, namely a dynamic partitioning of the search space, a distribution process based on a peer-to-peer communication framework, and a novel receiver-initiated, load balancing algorithm. The effectiveness of the distributed method has been evaluated on the well-known National Cancer Institute’s HIV-screening dataset, where the approach attains close-to linear speedup in a network of workstations.

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An Orthogonal Frequency Division Multiplexing (OFDM) communication system with a transmitter and a receiver. The transmitter is arranged to transmit channel estimation sequences on each of a plurality of band groups, or bands, and to transmit data on each of the band groups or bands. The receiver is arranged to receive the channel estimation sequences for each band group or band to calculate channel state information from each of the channel estimation sequences transmitted on that band group or band and to form an average channel state information. The receiver receives the transmitted data, transforms the received data into the frequency domain, equalizes the received data using the channel state information, demaps the equalized data to re-construct the received data as soft bits and modifies the soft bits using the averaged channel state information.

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Dual Carrier Modulation (DCM) is currently used as the higher data rate modulation scheme for Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) in the ECMA-368 defined Ultra-Wideband (UWB) radio platform. ECMA-368 has been chosen as the physical radio platform for many systems including Wireless USB (W-USB), Bluetooth 3.0 and Wireless HDMI; hence ECMA-368 is an important issue to consumer electronics and the user’s experience of these products. In this paper, Log Likelihood Ratio (LLR) demapping method is used for the DCM demaper implemented in fixed point model. Channel State Information (CSI) aided scheme coupled with the band hopping information is used as the further technique to improve the DCM demapping performance. The receiver performance for the fixed point DCM is simulated in realistic multi-path environments.

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Several recent hypotheses, including sensory drive and sensory exploitation, suggest that receiver biases may drive selection of biological signals in the context of sexual selection. Here we suggest that a similar mechanism may have led to convergence of patterns in flowers, stingless bee nest entrances, and pitchers of insectivorous plants. A survey of these non-related visual stimuli shows that they share features such as stripes, dark centre, and peripheral dots. Next, we experimentally show that in stingless bees the close-up approach to a flower is guided by dark centre preference. Moreover, in the approach towards their nest entrance, they have a spontaneous preference for entrance patterns containing a dark centre and disrupted ornamentation. Together with existing empirical evidence on the honeybee's and other insects' orientation to flowers, this suggests that the signal receivers of the natural patterns we examined, mainly Hymenoptera, have spontaneous preferences for radiating stripes, dark centres, and peripheral dots. These receiver biases may have evolved in other behavioural contexts in the ancestors of Hymenoptera, but our findings suggest that they have triggered the convergent evolution of visual stimuli in floral guides, stingless bee nest entrances, and insectivorous pitchers.

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Despite theoretical predictions, dishonest signalling has rarely been observed in aggressive interactions. We present evidence of such signalling in the nonpollinating. g wasp Philotrypesis sp. A ex Ficus rubiginosa. First, morphometric data indicated that an alternative 'atypical' male morph (17.8% of individuals) exists that tends to be larger in body size and has longer mandibles for a given body size than other 'typical' males. Second, behavioural observations suggested that males use mandible gape width (which depends on mandible length) as a cue to assess opponents before fights and retreat without escalating if they are unlikely to win, and, probably because their greater mandible gape width causes more opponents to retreat without escalating, that atypical males engaged in fewer fights than typical males for a given body size but had higher mating success. Third, atypical males were less likely to win fights than typical males of similar mandible length relative to opponents. In addition, we found that atypical males incur more injuries (greater receiver-dependent signal costs) than typical males of similar body size relative to rivals. We discuss the implications of our findings for future work on dishonest signalling. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

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In this review we describe how concepts of shoot apical meristem function have developed over time. The role of the scientist is emphasized, as proposer, receiver and evaluator of ideas about the shoot apical meristem. Models have become increasingly popular over the last 250 years, and we consider their role. They provide valuable grounding for the development of hypotheses, but in addition they have a strong human element and their uptake relies on various degrees of persuasion. The most influential models are probably those that most data support, consolidating them as an insight into reality; but they also work by altering how we see meristems, re-directing us to influence the data we collect and the questions we consider meaningful.

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This paper investigates and evaluates the process of knowledge transfer in construction projects. Due to the highly competitive nature of business environments, knowledge transfer between organisations has become increasingly popular in recent years. However, although organisations can realise remarkable benefits by transferring knowledge from one unit to another, successful knowledge transfer can be difficult to achieve. The discussions presented in the paper are mainly based on findings of two case studies. The two cases were selected from Private Finance Initiative (PFI) projects in the UK. According to the case study findings, different stages of a knowledge transfer process can be overlapped, omitted, repeated as well as intermitted and then restarted. One of the significant findings of the case studies was the role of the "knowledge mediator". In selected case studies, there were external consultants and expert staff in the form of knowledge mediators. The importance of their roles was frequently highlighted by the interview participants. They were not only facilitating the close liaison between the knowledge source and the receiver, but also their role was strongly associated with practices of translation and interpretation. This combined role of mediator/translator, therefore, appears to be particularly significant for inter-organisational knowledge transfer in PFI projects.

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In an ideal "reverberant" room, the energy of the impulse responses decays smoothly, at a constant rate of dB/s, so that gradually-decaying tails are added at the ends of sounds. Conversely, a single echo gives a flat energy-decay up to the echo's arrival time, which then drops abruptly, so that sounds with only echoes lack the decaying-tail feature of reverberation. The perceptual effects of these types of reflection pattern were measured with test-words from a continuum of steps between "sir" and "stir", which were each embedded in a carrier phrase. When the proportion of reflected sound in test-words is increased, to a level above the amount in the carrier, the test words sound more like "sir". However, when the proportion of reflected sound in the carrier is also increased, to match the amount in the test word, there can be a perceptual compensation where test words sound more like "stir" again. A reference condition used real-room reverberation from recordings at different source to receiver distances. In a synthetic-reverberation condition, the reflection pattern was from a "colorless" impulse response, comprising exponentially-decaying reflections that were spaced at intervals. In a synthetic-echo condition, the reflection pattern was obtained from the synthetic reverberation by removing the intervals between reflections before delaying the resulting cluster relative to the direct sound. Compensation occurred in the reference condition and in different types of synthetic reverberation, but not in synthetic-echo conditions. This result indicates that the presence of tails from reverberation informs the compensation mechanism.

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Background Screening instruments for autistic-spectrum disorders have not been compared in the same sample. Aims To compare the Social Communication Questionnaire (SCQ), the Social Responsiveness Scale (SRS) and the Children's Communication Checklist (CCC). Method Screen and diagnostic assessments on 119 children between 9 and 13 years of age with special educational needs with and without autistic-spectrum disorders were weighted to estimate screen characteristics for a realistic target population. Results The SCQ performed best (area under receiver operating characteristic curve (AUC)=0.90; sensitivity. 6; specificity 0.78). The SRS had a lower AUC (0.77) with high sensitivity (0.78) and moderate specificity (0.67). The CCC had a high sensitivity but lower specificity (AUC=0.79; sensitivity 0.93; specificity 0.46). The AUC of the SRS and CCC was lower for children with IQ < 70. Behaviour problems reduced specificity for all three instruments. Conclusions The SCQ, SRS and CCC showed strong to moderate ability to identify autistic-spectrum disorder in this at-risk sample of school-age children with special educational needs.

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We model the large scale fading of wireless THz communications links deployed in a metropolitan area taking into account reception through direct line of sight, ground or wall reflection and diffraction. The movement of the receiver in the three dimensions is modelled by an autonomous dynamic linear system in state-space whereas the geometric relations involved in the attenuation and multi-path propagation of the electric field are described by a static non-linear mapping. A subspace algorithm in conjunction with polynomial regression is used to identify a Wiener model from time-domain measurements of the field intensity.

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This paper discusses the design, implementation and synthesis of an FFT module that has been specifically optimized for use in the OFDM based Multiband UWB system, although the work is generally applicable to many other OFDM based receiver systems. Previous work has detailed the requirements for the receiver FFT module within the Multiband UWB ODFM based system and this paper draws on those requirements coupled with modern digital architecture principles and low power design criteria to converge on our optimized solution. The FFT design obtained in this paper is also applicable for implementation of the transmitter IFFT module therefore only needing one FFT module for half-duplex operation. The results from this paper enable the baseband designers of the 200Mbit/sec variant of Multiband UWB systems (and indeed other OFDM based receivers) using System-on-Chip (SoC), FPGA and ASIC technology to create cost effective and low power solutions biased toward the competitive consumer electronics market.

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The relative fast processing speed requirements in Wireless Personal Area Network (WPAN) consumer based products are often in conflict with their low power and cost requirements. In order to solve this conflict the efficiency and cost effectiveness of these products and the underlying functional modules become paramount. This paper presents a low-cost, simple, yet high performance solution for the receiver Channel Estimator and Equalizer for the Mutiband OFDM (MB-OFDM) system, particularly directed to the WiMedia Consortium Physical Later (ECMA-368) consumer implementation for Wireless-USB and Fast Bluetooth. In this paper, the receiver fixed point performance is measured and the results indicate excellent performance compared to the current literature(1).