384 research outputs found

    Statistical Multiplexing of H.264 video streams using Structural Similarity Information

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    In this paper, we propose a method to broadcast digital video programs in which the channel capacity is dynamically distributed among video programs according to each video program particular complexity. A bit rate control algorithm based on the Structural Similarity Index as the measure of video program complexity is examined. Initial results show that a uniform picture quality among video programs can be obtained

    Statistical Multiplexing of H.264 programms

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    The advent of H.264/AVC is going to change the way Digital Television programs are broadcast. Each program can be independently encoded or jointly encoded resulting thus in a more efficient way to distribute the available channel bandwidth. This paper presents a combined coding scheme for multi-program video transmission in which the channel capacity is distributed among the programs according to the program complexities. A complexity bit rate control algorithm based on the Structural Similarity Index (SSIM) is proposed. SSIM metric is presented under the hypothesis that the Human Visual System (HSV) is very specialized in extracting structural information from a video sequence but not in extracting the errors. Thus, a measurement on structural distortion should give a better correlation to the subjective impression. Current simulations have demonstrated very promising results showing that the algorithm can effectively control the complexity of the multi-program encoding process whilst improving overall subjective

    Generic Framework for Video Analysis

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    In this paper we propose a framework for development of video analysis and description systems, in an easy and interactive way. Due to the architecture design the developed software can run on different operating systems and on distributed environments

    Atores num Mundo Global: a análise do ciclo de vida e o processo de avaliação de impacte ambiental como instrumento de apoio à tomada de decisão

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    O tema da presente dissertação inscreve-se na complexa problemática da informação de suporte à tomada de decisão de infraestruturas básicas, com destaque para as denominadas “Trans European Networks – TENS”, infraestruturas de transportes, energia e telecomunicações. Tais processos de decisão, para além das abordagens mais comuns utilizadas nos Estudos de Impacte Ambiental (EIA), podem (devem?) considerar outras perspetivas assentes em considerações de impactes no ciclo de vida, em concreto a Análise do Ciclo de Vida (ACV), e integrar abordagens de procura de sustentabilidade nas vertentes económicas, ambiental e social. Aí chegados, estaremos mais próximos das estradas com melhor desempenho ambiental. A importância do tema firma-se na constatação da ansiedade e expectativas que normalmente envolvem os processos de decisão deste tipo de infraestruturas, principalmente quando as pessoas tomam conhecimento (1) que a sua concretização pode gerar impactes negativos no ambiente, de forma não limitada ao espaço local onde se inserem, mas antes causando efetivos danos ambientais a uma escala mais global. Nestas circunstâncias é comum sobrevirem processos de tensão entre as necessidades locais, promotoras dos empreendimentos, e as dinâmicas globais, conflitos que podem ser evitados, ou pelo menos atenuados, na medida em que os respetivos processos de decisão sejam mais informados e mais esclarecidos e esclarecedores da opinião pública. Não há dúvida que este género de projetos/empreendimentos/infraestruturas serão tendencialmente mais bem aceites pela Sociedade na medida em que sejam vistos local, regional e globalmente, como “ambientes construídos” que se baseiam na eficiência dos recursos e em princípios ecológicos saudáveis, que contribuem para o desenvolvimento económico, para a melhoria das condições de vida das populações e para a coesão social e territorial.Para um processo de decisão ser convenientemente instruído, é crucial que realce todos estes aspetos perante a sociedade. A estrutura adotada no trabalho articula uma primeira parte de embasamento teórico, com uma segunda parte que experiencia o estudo de um caso concreto, a abordagem de sustentabilidade na procura de uma estrada com satisfatório desempenho ambiental

    POF-based specklegram sensor post processing comparative: methods for extracting breath and heart rate

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    Continuous patient monitoring has been evidenced as very beneficious for reducing degeneration1. Due to this, a POF specklegram sensor has been developed based on a previous work2. This work presents a comparative between analysis methods of the specklegram signal for achieving a precise and robust non-contact monitor system. Two different techniques have been used: one based on the Fast Fourier Transform (FFT) and the other based on the Hilbert Transform (HT). Each technique has been employed with two different methods, for heart rate and breath rhythm. The different algorithms are tested on 10 volunteers of different ages and sex.This work has been sponsored by the Spanish Ministry of Science, Innovation and Universities and European Regional Development Fund (ERDF) across projects RTC-2017-6321-1 AEI/FEDER,UE and TEC2016-76021-C2-2-R AEI/FEDER, UE

    Low-cost fiber specklegram sensor for noncontact continuous patient monitoring

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    Different low-cost approaches based on fiber specklegram sensors are employed to measure the physiological activity of patients lying in bed. This study is conducted over 20 volunteers to measure the movement and heart rate (HR) using two different sensor designs placed at two different bed locations. Three different processing methods are developed and tested in order to extract useful information from the measured data. The results suggest that a stretched fiber optic configuration under the head of the person lying in bed is the optimal configuration to detect HR and motion, nonetheless the other tested possibilities also exhibit remarkably good performances. On the other hand, the three proposed processing methods also achieve a good precision in the HR detection. The sensor implementation is simple, not requiring any special conditions, and it provides robust performance. This leads to the conclusion that fiber specklegram technology is a feasible method to be used in real situations for heartbeat and movement monitoring.This work has been supported by the Spanish Government through the Ministry of Economy and Competitiveness projects TEC2013-47264-C2-1-R and TEC2016-76021-C2-2-R

    Primer registro de atractocerus brasiliensis lepeletier & audinet-serville (coleoptera: lymexylidae) para Jalisco, México.

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    This is the first record of Atractocerus brasiliensis (Coleoptera: Lymexylidae) from Jalisco State, Mexico

    Wavelength domain multiplexed fiber specklegram sensor

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    In this work, a low-cost WDM interrogation system has been proposed and experimentally tested to obtain twoindependent channels of a fiber specklegram sensor. Two lasers of different wavelengths have been launched into twomultimode Polymer Optical Fibers (POFs) and then combined through a coupler before their interrogation using a RBGcamera. By analyzing each color of the video sequence, the two fiber channels can be independently obtained. Besides,the speckle sensitivity has been also studied by analyzing different properties of speckle patterns such as their contrast orthe speckle size. The achieved results help to the development of new fiber specklegram sensors by allowing a directcomparison between two specklegrams of different properties

    The Ubiquitin Proteasome System in Neuromuscular Disorders: Moving Beyond Movement

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    Neuromuscular disorders (NMDs) affect 1 in 3000 people worldwide. There are more than 150 different types of NMDs, where the common feature is the loss of muscle strength. These disorders are classified according to their neuroanatomical location, as motor neuron diseases, peripheral nerve diseases, neuromuscular junction diseases, and muscle diseases. Over the years, numerous studies have pointed to protein homeostasis as a crucial factor in the development of these fatal diseases. The ubiquitin-proteasome system (UPS) plays a fundamental role in maintaining protein homeostasis, being involved in protein degradation, among other cellular functions. Through a cascade of enzymatic reactions, proteins are ubiquitinated, tagged, and translocated to the proteasome to be degraded. Within the ubiquitin system, we can find three main groups of enzymes: E1 (ubiquitin-activating enzymes), E2 (ubiquitin-conjugating enzymes), and E3 (ubiquitin-protein ligases). Only the ubiquitinated proteins with specific chain linkages (such as K48) will be degraded by the UPS. In this review, we describe the relevance of this system in NMDs, summarizing the UPS proteins that have been involved in pathological conditions and neuromuscular disorders, such as Spinal Muscular Atrophy (SMA), Charcot-Marie-Tooth disease (CMT), or Duchenne Muscular Dystrophy (DMD), among others. A better knowledge of the processes involved in the maintenance of proteostasis may pave the way for future progress in neuromuscular disorder studies and treatments.Ministerio de Economía y Competitividad RTI2018-098645-B-10

    Sleep monitoring by a specklegram fiber optic sensor

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    Sleep monitoring is becoming more and more popular. This is due to the considerably large number of pathologies and illness related to sleep disorders.In this work a long-termmonitoring system based on a fiber-optic specklegram sensor is presented. The system has been tested under real scenarios and compared with a commercial wrist-based actigrapher. The results suggest that our sensor is highly accurate on detecting movements and can be far more precise than traditional wrist-based actigraphers.This work has beensupported by the Spanish Government through the Ministry of Economy and Competitiveness projects TEC2013-47264-C2-1-R and TEC2016-76021-C2-2-R (AEI/FEDER, UE)
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