• 제목/요약/키워드: Activity Detection

검색결과 1,141건 처리시간 0.027초

노인 낙상 후 충격량 측정 및 기립여부 판단 시스템 구현 (Development of fall Detection System by Estimating the Amount of Impact and the Status of Torso Posture of the Elderly)

  • 김충현;이영재;이필재;이정환
    • 전기학회논문지
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    • 제60권6호
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    • pp.1204-1208
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    • 2011
  • In this study, we proposed the system that calculates the algorithm with an accelerometer signal and detects the fall shock and it's direction. In order to gather the activity patterns of fall status and attach on the subject's body without consciousness, the device needs to be small. With this aim, it is attached on the right side of subject's waist. With roll and pitch angle which represent the activity of upper body, the fall situation is determined and classified into the posture pattern. The impact is calculated by the vector magnitude of accelerometer signal. And in the case of the elderly keep the same posture after fall, it can distinguish the situation whether they can stand by themselves or not. Our experimental results showed that 95% successful detection rate of fall activity with 10 subjects. For further improvement of our system, it is necessary to include tasks-oriented classifying algorithm to diverse fall conditions.

Purification and Characterization of Methyl Mercaptan Oxidase from Thiobacillus thioparus for Mercaptan Detection

  • Lee, Hyun-Ho;Kim, Sang-Joon;Shin, Hyun-Jae;Park, Ji-Yeon;Yang, Ji-Won
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제7권6호
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    • pp.375-379
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    • 2002
  • Methyl mercaptan oxidase was successfully induced in Thiobacillus thioparus TK-m using methyl mercaptan gas, and was purified for the detection of mercaptans. The purification procedure Involved a DEAE (diethylaminoethyl) -Sephacel, or Superose 12, column chromatography with recovery yields of 47.5 and 48.5%, and specific activities of 374 and 1240.8 units/mg-protein, respectively, The molecular weight of the purified methyl mercaptan oxidase was 66.1kDa, as determined by SDS-PAGE. The extract, from gel filtration chromatography oxidizes methyl mercaptan, producing formaldehyde, which can be easily detected by the purpald-coloring method. The optimized temperature for activity was found to be at 55$\^{C}$. This enzyme was inhibited by both NH$_4$Cl and (NH$_4$)$_2$SO$_4$, but was unaffected by either KCl or NaCl at less than 200 mM. With K$_2$SO$_4$, the activity decreased at 20 mM, but recovered at 150 mM. In the presence of methanol, full activity was maintained, but decreased in the presence of glycerin, ethanol and acetone 43, 78 and 75%, respectively.

통계적 비선형 차원축소기법에 기반한 잡음 환경에서의 음성구간검출 (Voice Activity Detection in Noisy Environment based on Statistical Nonlinear Dimension Reduction Techniques)

  • 한학용;이광석;고시영;허강인
    • 한국정보통신학회논문지
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    • 제9권5호
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    • pp.986-994
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    • 2005
  • 본 논문은 잡음 환경하에서 적응 가능한 음성구간검출를 구축하기 위하여 우도기반의 음성 특징 파라미터의 비선형 차원축소 방법을 제안한다. 제안하는 차원축소 방법은 음성/비음성 클래스에 대한 가우시아 확률 밀도 함수의 비선형적 우도값을 새로운 특징으로 취하는 방법이다. 음성구간검출기의 음성/비음성 결정은 우도비 검증(LRT)의 통계적 방법을 이용하며, 선형판별분석(LDA)에 의한 차원축소 결과와 성능을 비교한다. 실험 결과 제안된 차원 축소 방법으로 음성 특징 파라미터를 2차원으로 축소한 결과가 원래 특징백터의 차원에서의 결과와 대등한 성능을 확인하였다.

Detection of estrogenic hormone 17β-estradiol in soil samples by a recombinant yeast bioassay and supercritical fluid extraction

  • Shim, Jae-Han;Kim, Mi-Ra;Topp, Edward;Choi, Jeong-Heui;Mamun, Iqbal Rouf
    • 한국환경농학회지
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    • 제27권4호
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    • pp.447-455
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    • 2008
  • Recombinant yeast estrogenicity (YES) assay was used as a bioanalytical tool in order to screen $17{\beta}$-estradiol in the soil samples collected from different sites of South Korea. Solvent extraction and supercritical fluid extraction (SFE) methods were compared for the extraction of the estradiol from the soils. Most high detection of the estradiol based on YES assay was observed in the soils extracted with methanol. Different types of estrogenic hormones including $17{\beta}$-estradiol were suggested to be possibly exiting in the soils, since the methanol extracts of the soils showed an estrogenic activity that was not observed in the hexane extracts of the soil. SFE extracts showed estrogenic activity in some of the samples but methanol extract showed best activity.

Optimal Media Conditions for the Detection of Extracellular Cellulase Activity in Ganoderma neo-japonicum

  • Jo, Woo-Sik;Park, Ha-Na;Cho, Doo-Hyun;Yoo, Young-Bok;Park, Seung-Chun
    • Mycobiology
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    • 제39권2호
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    • pp.129-132
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    • 2011
  • To determine the optimal media conditions for the detection of the extracellular cellulase activity in Ganoderma neo-japonicum, we varied three media conditions: dye reagent, pH, and temperature. We evaluated the use of four dyes, Congo red, phenol red, remazol brilliant blue, and trypan blue. To observe the effect of pH on the chromogenic reaction, we tested media ranging from 4.5 to 8.0. To research the effect of temperature on the clear zone and the fungus growing zone, we tested temperatures ranging from 15 to $35^{\circ}C$. On the whole, the best protocol called for Ganoderma neo-japonicum transfer onto media containing Congo red with a pH of 7.0, followed by incubation at $25^{\circ}C$ for 5 days. Our results will be useful to researchers who study extracellular enzyme activity in Ganoderma neo-japonicum.

Optimal Medium Conditions for the Detection of Cellulolytic Activity in Ganoderma lucidum

  • Jo, Woo-Sik;Bae, Soon-Hwa;Cho, Doo-Hyun;Park, So-Deuk;Yoo, Young-Bok;Park, Seung-Chun
    • Mycobiology
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    • 제37권4호
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    • pp.313-316
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    • 2009
  • To determine the optimal medium conditions for the detection of the cellulolytic activity in Ganoderma lucidum, we varied three media conditions: dye reagent, pH, and temperature. First, we evaluated the use of four dyes, Congo Red, Phenol Red, Remazol Brilliant Blue, and Trypan Blue. To observe the effect of pH on the chromogenic reaction, we also made and tested various media spanning acidic and alkaline pHs, ranging from 4.5 to 8.0. Furthermore, in order to research the effect of temperature on the clear zone and the fungus growing zone, we tested temperatures ranging from 15 to $35{^{\circ}C}$. On the whole, the best protocol called for Ganoderma lucidum transfer onto media containing Congo red with pH adjusted to 7.0, followed by incubation at $25{^{\circ}C}$ for 5 days. Our results will be useful to researchers who aim to study extracellular enzyme activity in Ganoderma lucidum.

Minimum detectable activity of plastic scintillator for in-situ beta measurement system in ground water

  • Choi, Woo Nyun;Lee, UkJae;Bae, Jun Woo;Kim, Hee Reyoung
    • Nuclear Engineering and Technology
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    • 제51권4호
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    • pp.1169-1175
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    • 2019
  • The minimum detectable activity (MDA) value was derived according to the flow rate of the sample and degree of amplification of the device by sending the sample directly from the collection site to the detection part through a pump. This method can lead to reduction in time and cost compared to the existing measurement method that uses a pre-treatment process. In this study, experiments were conducted on $^3H$ and $^{90}Sr$, which are the major pure beta-emitting radionuclides, by setting the sample flow rate and the amplification gain as factors. The MDA values were derived according to the flow rates, considering that the flow rate can affect the MDA values. There were no change in the MDA under different flow rates of 0, 600, 800, and 1000 mL/min. Therefore, it was confirmed that the flow rate may not be considered when collecting samples for monitoring in actual field. As the degree of amplification of the amplifier increased, the time required to reach the target MDA decreased. When the amplification was quadrupled, the detection efficiency increased by approximately 23.4 times, and the time to reach the MDA decreased to approximately 1/550 times. This method offers the advantage of real-time on-site monitoring.

궤환구조를 가지는 변별적 가중치 학습에 기반한 음성검출기 (Voice Activity Detection Based on Discriminative Weight Training with Feedback)

  • 강상익;장준혁
    • 한국음향학회지
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    • 제27권8호
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    • pp.443-449
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    • 2008
  • 이동통신에서 배경잡음이 존재하는 실제 환경에서 음성신호처리의 가장 중요한 이슈중의 하나는 강인한 음성검출기를 설계하는 것이다. 상대적으로 간단하면서도 성능이 우수하여 대표적인 음성검출기로 사용되는 통계적모델기반 기법은 각 주파수 채널별 우도비를 이용하여 음성검출 검출식을 만들어내는 방식이다. 최근, 변별적 가중치 학습 (discriminative weight training)을 이용하여 주파수 체널별 가중치가 인가된 우도비를 이용한 음성검출 결정식을 갖는 음성검출기가 제안 되었으며 상대적으로 우수한 성능을 보였다. 본 연구에서는 기존의 변별적 가중치 학습의 입력벡터에 이전프레임의 결정식을 궤환구조형태를 바탕으로 추가하는 새로운 방식을 제안한다. 제안된 기법은 비정상 (non-staionary) 잡음 환경에서 객관적인 방법을 통해 상호비교 분석되었으며 결론적으로 우수한 성능을 보였다.