9 documents found, page 1 of 1
Quiosque de saúde: Que fatores influenciam a decisão sobre como e quando utilizar?
Rodrigues, João ManuelEducar pessoas através do uso de tecnologias de informação tem sido reconhecida como uma medida eficaz para desenvolver o seu conhecimento e aptidões, o que aumenta a promoção de um comportamento saudável. Os quiosques de saúde surgem como um instrumento para a promoção da saúde, a prevenção e a vigilância de doenças crónicas não transmissíveis. As possibilidades de desenvolvimento do conceito são enormes, sali...
The symmetry of oligonucleotide distance distributions in the human genome
Tavares, Ana Helena; Afreixo, Vera; Rodrigues, João Manuel; Bastos, CarlosThe inter-oligonucleotide distance is defined as the distance to the next occurrence of the same oligonucleotide. In this work, using the inter-oligonucleotide distance concept, we develop new methods to evaluate the lack of homogeneity in symmetric word pairs (pairs of reversed complement oligonucleotides), in equivalent composition groups. We apply the developed methods to the human genome and we conclude tha...
Audio compression: discussion of an alternative approach
Rodrigues, João Manuel; Tomé, Ana MariaIn this paper we present and dicuss a new algorithm for the compression of audio signals in which we are currently working. Backward-adaptive quantization, a fundamental innovation that differentiates this from other perceptual audio coders, is justified for its multiple advantages. We conclude with a discussion of some issues related to the design of the various components of the coder we are developing.; Nest...
Auditory models in audio coding
Rodrigues, João Manuel; Tomé, Ana Maria; Silva, Tomás Oliveira eTwo strategies have been used to evaluate the perceptual significance of a distortion introduced into a signal: the masking threshold concept, and the internal representation approach. Psychoacoustic models found in the perceptual audio coding literature generally follow the first approach in spite of the recognized unsuitability of the approach for the task. The more plausible internal representation approach ...
Advanced audio compression for multimedia
Rüdiger, Lars; Tomé, Ana Maria; Rodrigues, João ManuelThis paper reports the implementation of a coding system that includes the psychoacoustic aspects of the human ear to achieve compression of audio data while keeping the quality of the audio signal after the reconstruction.; Este artigo descreve a implementação de um sistema de codificação que integra aspectos psico-acústicos do ouvido humano para conseguir compressão dos dados áudio mantendo a q...
Clinical aspects of infective endocarditis - A report of 5 cases in a departmen...
Caires, Graça; Caldeira, Paula; Freitas, Ema; Freitas, Luís; Sousa, Sirgado; Pereira, Décio; Ferreira, Caldeira; Rodrigues, João Manuel; Cardoso, AlmadaInfective endocarditis is a potentially life threatening disease. It is an infection of the endocardium and the heart valves (specially abnormal and susceptible cardiac structures), most often resulting from bacteremia. Infective endocarditis has a broad clinical picture, with systemic and multiorgan impairment. Major complaints are fever and others systemic symptoms such as night sweats, loss of appetite, wei...
Codificação perceptual de áudio usando quantização retro-adaptativa
Rodrigues, João Manuel; Tomé, Ana Maria PerfeitoThis paper presents a new coding/compression algorithm for high-quality digital audio signals. The new codercomprehends a nonuniform filter bank, gain-adaptive logaritbmic quantizers, arithmetic coding, and an explicit psychoacoustic model that adapts the quantizers according to perceptual criteria. The new system differs from other perceptual coders in that its quantizers are backward-adaptive: the adaptation ...
High quality audio coding using backward estimation of perceptual phenomena
Rodrigues, João Manuel; Tomé, Ana Maria PerfeitoThis paper presents a new audio compression algorithm that includes a nonuniform filter bank, gain-adaptive logarithmic quantizers, arithmetic entropy coding and an explicit psychoacoustic model to adapt the quantization according to perceptual considerations. Unlike existing perceptual coders, the new system is backward-adaptive, i.e: adaptation depends exclusively on already quantized samples, not on the orig...
A backward-adaptive perceptual audio coder
Rodrigues, João Manuel; Tomé, Ana MariaThis paper presents a new audio compression algorithm that includes a nonuniform filter bank, gain-adaptive logarithmic quantizers, arithmetic entropy coding and an explicit psychoacoustic model to adapt the quantization according to perceptual considerations. Unlike existing perceptual coders, the new system is backward-adaptive, i.e., adaptation depends exclusively on already quantized samples, not on the ori...