• Title/Summary/Keyword: Biological Signal

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Estimation of Ultrasound Attenuation Coefficient by Homomorphic Deconvolution Method (Homomorphic Deconvolution 법에 의한 초음파 감쇄정수 추정)

  • Hong, Seung-Hong;Huh, Woong
    • Journal of Biomedical Engineering Research
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    • v.5 no.1
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    • pp.39-46
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    • 1984
  • In order to improve the performance of ultrasonic diagnostic equipment, it is important to development the signal processing considering the ultrasonic properties of biological medium and propagation mechanism in tissue. Attenuation coefficient is not only important factor to analyze propagation properties, but also it is significant to estimate it in view of tissue characterization, so we show one of the method to estimate attenuation coefficient of biological tissue and the results of estimation.

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Higher Order Knowledge Processing: Pathway Database and Ontologies

  • Fukuda, Ken Ichiro
    • Genomics & Informatics
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    • v.3 no.2
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    • pp.47-51
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    • 2005
  • Molecular mechanisms of biological processes are typically represented as 'pathways' that have a graph­analogical network structure. However, due to the diversity of topics that pathways cover, their constituent biological entities are highly diverse and the semantics is embedded implicitly. The kinds of interactions that connect biological entities are likewise diverse. Consequently, how to model or process pathway data is not a trivial issue. In this review article, we give an overview of the challenges in pathway database development by taking the INOH project as an example.

Effects of pegylation on physical and biological activities of N-acetylphytosphingosine, a short chain phytoceramide

  • Park, J. H.;Park, C. Y.;Y. A. Hwang;Kim, E. J.;Kim, J. W.;Park, C. S.
    • Proceedings of the SCSK Conference
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    • 2003.09a
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    • pp.498-498
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    • 2003
  • Sphingolipids are important structural components of the stratum corneum lipids and serve the epidermal permeability barrier function. Recent investigations on biological activities of sphingolipids have revealed that they have a number of important biological functions in the cell such as cell proliferation and differentiation, anti-inflammation, mediation of signal transduction and many more.(omitted)

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Classification of Transient Signals in Ocean Background Noise Using Bayesian Classifier (베이즈 분류기를 이용한 수중 배경소음하의 과도신호 분류)

  • Kim, Ju-Ho;Bok, Tae-Hoon;Paeng, Dong-Guk;Bae, Jin-Ho;Lee, Chong-Hyun;Kim, Seong-Il
    • Journal of Ocean Engineering and Technology
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    • v.26 no.4
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    • pp.57-63
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    • 2012
  • In this paper, a Bayesian classifier based on PCA (principle component analysis) is proposed to classify underwater transient signals using $16^{th}$ order LPC (linear predictive coding) coefficients as feature vector. The proposed classifier is composed of two steps. The mechanical signals were separated from biological signals in the first step, and then each type of the mechanical signal was recognized in the second step. Three biological transient signals and two mechanical signals were used to conduct experiments. The classification ratios for the feature vectors of biological signals and mechanical signals were 94.75% and 97.23%, respectively, when all 16 order LPC vector were used. In order to determine the effect of underwater noise on the classification performance, underwater ambient noise was added to the test signals and the classification ratio according to SNR (signal-to-noise ratio) was compared by changing dimension of feature vector using PCA. The classification ratios of the biological and mechanical signals under ocean ambient noise at 10dB SNR, were 0.51% and 100% respectively. However, the ratios were changed to 53.07% and 83.14% when the dimension of feature vector was converted to three by applying PCA. For correct, classification, it is required SNR over 10 dB for three dimension feature vector and over 30dB SNR for seven dimension feature vector under ocean ambient noise environment.

Development of biological signal optical transmission system (생체신호처리용 광전송시스템 개발)

  • 박종대;손진우;서희돈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.9
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    • pp.1933-1940
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    • 1997
  • The development of CMOS IC chip and external system with optical transmission sytem is proposed in this paper, which deal with 4 subject 4 channel biological signals, receive and transmit biological signals to the external system using LED and infrared light of photodiode. This system decreases the dependency of power supply voltage to the COMS IC chip. A newenforce synchronization technique using infrared bi-directional communication has ben proposed. The telemetner IC with the size of $5.1{\times}5.1mm^2$ has the followingfunctions:receiving of command signal, initialization of internal state of all functional blocks, decoding of subject selection signal, time division multiplexing of 4-channel modulated biological signals, transmission of modulated signals to external system, and auto power down control. To confirm the total telemetry system, electrocardogram is transmitted and received to the external system using optical link.

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