• Title/Summary/Keyword: Physiological signal analysis

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Experimental Study on Thermal Comfort Sensation of Korean and Physiological Signal Part I : Analysis of Subjective Judgement in Winter Experiment (한국인의 온열쾌적감 및 생리신호에 관한 연구 (Part I : 겨울철 체감실험 결과))

  • 주익성;김동규;금종수;최광환;이구형;임금식
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1997.11a
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    • pp.107-112
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    • 1997
  • 본 연구의 목적은 겨울철 난방시 한국인의 온열감각과 온열환경지표 사이의 상관관계 및 ASHRAE Standard 55-74의 쾌적영역과 한국인의 쾌적영역을 체감실험을 통해 규명 및 제시하는 것이다. 유니폼을 착용한 피실험자는 온도, 습도, 기류 등이 조절되는 환경시험실에서 2시간동안 체재하면서 매 15분 마다 전신온냉감, 쾌불쾌감 등을 신고하였다. 또한 인체의 3부위에서 피부온도, 환경시험실의 온도 및 습도를 매 20초 간격으로 측정하였다. 이상의 체감실험을 통해 아래의 결론을 얻었다. 1)평균피부온도가 증가함에 따라 TSV는 선형적으로 증가하며 열적으로 중립감을 느낄 때의 평균피부온도는 청년 34.$0^{\circ}C$, 고령자 33.5$^{\circ}C$이다. 2)TSV=0일때 청년의 중립 SET*는 25.5$^{\circ}C$, 고령자의 중립 SET*는 27.$0^{\circ}C$이다. 3)한국인의 쾌적범위는 청년의 경우 SET*의 경우 24.2-26.8$^{\circ}C$, 고령자의 경우 SET*25.7-28.2$^{\circ}C$로 ASHRAE St.55-74의 권장 쾌적범위 (22.0-25.4$^{\circ}C$)보다 다소 고온지향적이다.

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Evaluation of Thermal Comfort for the Vertical Room Air Temperature Difference and for the Control of Air Stream based on Physiological Signal Analysis (실내 상하온도차와 기류방식 제어에 따른 온열쾌적성 평가를 위한 생리신호분석)

  • 이낙법;임재중;배동석;금종수;최호선;이구형
    • Science of Emotion and Sensibility
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    • v.2 no.1
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    • pp.147-155
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    • 1999
  • 온열쾌적감에 영향을 주는 중요한 요인들로는 온도, 습도, 기류 등의 물리적 요인과 성별이나 체질 등 뿐만 아니라 온열환경에서 느끼는 인간의 감성적인 측면도 요인으로 작용한다. 본 연구에서는 여러 가지 온열 환경 중에서 실내의 상하온도차와 기류방식의 제어에 따른 생체반응의 변화, 및 감성의 변화를 관찰하여 온열환경에 따른 인간의 온열쾌적감을 평가하기 위해 생리신호를 측정, 분석하였다. 인간에게 가장 쾌적함을 주는 최적의 실내 상하온도차와 기류제어방식을 구현하기 위한 평가방법으로 MST(mean skin temperature)분석 및 HRV(heart rate variability) 분석과 EEG 주파수 스펙트럼 분석을 시행하였다. 그 결과 실내의 상하온도차는 23$^{\circ}C$의 머리부위 온도에서 발 부위와의 온도차가 -3$^{\circ}C$일 때 가장 쾌적한 조건으로 나타났고, 기류제어방식은 감성기류조건에서 가장 쾌적함을 보였다. 본 연구를 통해 실내의 상하온도차와 기류방식에 대한 온열환경의 쾌적조건을 설정하였고, HRV 분석과 EEG의 주파수 분석이 주판신소설문평가와 유의한 결과를 나타내어 이러한 생리신호의 분석이 인간의 감성적 측면을 고려한 온열쾌적성을 펑가하는데 보다 객관적이고 신뢰성 있는 평가지표로 이용될 수 있음을 제시하였다.

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Empirical Study of Air Conditioner Control Algorism for Comfort Sleeping (쾌적수면을 위한 에어컨 알고리즘에 관한 실증연구)

  • Kum, Jong-Soo;Kim, Dong-Gyu
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.12
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    • pp.808-813
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    • 2008
  • The study was to evaluate the air-conditioning of sleep algorithm. The algorithm was developed through the analysis of brain waves and MST, the experiments using air conditioner was performed in a apartment bedroom. Five female subjects were participated for the experiment. Eight hours of data collection a day was performed under different algorithm, case A, case B and case C. Physiological signals, EEG, ECG, EOG, and EMG, were obtained using polygraph and converted into digital signal. Then, subjects were asked to answer the questionnaire about their thermal sensation after experiment in bedroom. Sleep stages were classified, then TST, Sleep latency and Sleep efficiency were calculated for the three different air conditioner algorithm. As results, TST, Sleep efficiency, questionnaire showed the higher values for Case B algorism than that for other algorism. On the other hand, SWS latency was lower than for other conditions. Therefore, it was concluded that Case B of the algorithm was the best for comfortable and deep sleep.

Time-Frequency Analysis of EEGs Evoked by Tactile Stimulation (피부자극에 의해 유발되는 뇌파의 Time-Frequency 분석)

  • Yeo, H.S.;Oh, S.H.;Im, J.J.;Sohn, J.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.11
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    • pp.243-246
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    • 1996
  • This study was peformed to characterize the physiological signal prior to develop an algorithm which quantifies EEGs evoked by tactile stimulation. The experiment was devised with four experimental conditions, which were control and two levels of pressures in tactile sensation. Twenty subjects were used to obtain EEGs while applying tactile stimulation using two types of textiles, soft towel and sand paper, to the right hand of each subject. EEGs were acquired for 20 seconds, and each trial was repeated five times randomly at the different levels of stimulus intensities. The index, $S_{n}$, was obtained by calculating the ratio of energy distribution in the time-frequency plot for each scored psychological state of the subject. The results showed that dominant aspects of the EEG signals have their maximal frequencies concentrated at a lower ranges for the resting and pleasant state, while the spectral energies were distributed to higher frequency ranges when subjects experience an unpleasant emotion.

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Measurement and Analysis of Rodent Biological Signals using Telemetry System (원격측정장치를 이용한 설치류의 생체신호 측정 및 분석)

  • Kim, Chang-Hwan;Hur, Gyeong-Haeng
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.6
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    • pp.1159-1165
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    • 2011
  • Telemetry techniques of rats have been used for assessing safety pharmacology of drugs and chemicals. Biological signals including blood pressure and heart rate measured under anesthesia were significantly different from those obtained under normal conditions. The stress of restraint in awake animals can also affect the accuracy of physiological evaluation. This paper details the surgery required to allow key cardiovascular parameters to be determined. The telemetric measurement of cardiovascular parameters such as blood pressure, heart rate, electrocardiograph(ECG) established. We carried out the continuous monitoring of cardiovascular parameters using the telemetry system in F344 rats. During the measurement, no significant changes were observed in the heart rate and blood pressure. ECG signals and body temperature were also constant during the measurement of biological signals. With the results of this study, we conclude that this telemetry system can be applied usefully for the assesment of biological parameters in the rats.

Shikonin Modulates Cell Proliferation by Inducing Apoptosis in LLC Cells via MAPK Regulation and Caspase Activation

  • Lee, Soo-Jin;Kim, Sung-Hoon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.2
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    • pp.501-507
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    • 2005
  • Shikonin is a chemically characterized component of traditional herbal medicine, the root of Lithospermum erythrorhizon and has been shown to possess antitumor activities. Here we investigated anticancer potential of shikonin and its possible mechanism of action in LLC cells. Shikonin inhibited the proliferation of LLC cells in a concentration-dependent manner. It was also demonstrated that shikonin induced apoptosis in LLC cells by Annexin V staining and TUNEL staining analysis. Shikonin treatment was caused that decrease of Bcl-2, activation of caspases and cleavage of PARP. And shikonin also induced that the activation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38. Interestingly, the cell proliferation inhibition induced by shikonin was recovered by specific inhibitors of JNK and p38 but the inhibitor of MEK, the upstream kinase of ERK, did not recover. Additionally, shikonin administration at doses of 5 mg/kg in C57BL/6 mice strongly inhibited the primary tumor growth of LLC. Taken together, these results suggest that shikonin may suppress LLC cell proliferation by inducing an apoptotic process via activation of caspases and MAPKs

Prediction of the Successful Defibrillation using Hilbert-Huang Transform (Hilbert-Huang 변환을 이용한 제세동 성공 예측)

  • Jang, Yong-Gu;Jang, Seung-Jin;Hwang, Sung-Oh;Yoon, Young-Ro
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.5
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    • pp.45-54
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    • 2007
  • Time/frequency analysis has been extensively used in biomedical signal processing. By extracting some essential features from the electro-physiological signals, these methods are able to determine the clinical pathology mechanisms of some diseases. However, this method assumes that the signal should be stationary, which limits its application in non-stationary system. In this paper, we develop a new signal processing method using Hilbert-Huang Transform to perform analysis of the nonlinear and non-stationary ventricular fibrillation(VF). Hilbert-Huang Transform combines two major analytical theories: Empirical Mode Decomposition(EMD) and the Hilbert Transform. Hilbert-Huang Transform can be used to decompose natural data into independent Intrinsic Mode Functions using the theories of EMD. Furthermore, Hilbert-Huang Transform employs Hilbert Transform to determine instantaneous frequency and amplitude, and therefore can be used to accurately describe the local behavior of signals. This paper studied for Return Of Spontaneous Circulation(ROSC) and non-ROSC prediction performance by Support Vector Machine and three parameters(EMD-IF, EMD-FFT) extracted from ventricular fibrillation ECG waveform using Hilbert-Huang transform. On the average results of sensitivity and specificity were 87.35% and 76.88% respectively. Hilbert-Huang Transform shows that it enables us to predict the ROSC of VF more precisely.

Expression Patterns of Bacillus subtilis Diacylglycerol Kinase Gene Induced by Physiological Stimuli (Bacillus subtilis dgk (diacylglycerol kinase) 유전자의 생리적 자극에 의한 유도발현)

  • Lee, Mi-Young;Suh, Seok-Jong;Lee, Jin-Hyung;Song, Bang-Ho;Kim, Jong-Cuk
    • Microbiology and Biotechnology Letters
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    • v.30 no.1
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    • pp.15-20
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    • 2002
  • Diacylglycerol kinase (DGK) phosphorylates the second messenger diacylglycerol (DAG) to phosphatidic acid and it may play a role in signal transduction in Escherichia coli as well as in eukaryotic cells. In addition, DGK is important for microorganisms to adapt to several physiological stimuli. In Bacillus subtilis, the effect of stress on dgk transcription was examined by northern hybridization. The high level of dgk transcription was induced against high osmolarity, low pH value and low temperature. Transcriptional analysis revealed that the dgk gene and dgk upstream locus (ORF2, ORF3 and ORF4) were transcribed as a polycistronic mRNA to form an approximately 2.5 kb transcript.

Nitrate enhances the secondary growth of storage roots in Panax ginseng

  • Kyoung Rok Geem ;Jaewook Kim ;Wonsil Bae ;Moo-Geun Jee ;Jin Yu ;Inbae Jang;Dong-Yun Lee ;Chang Pyo Hong ;Donghwan Shim;Hojin Ryu
    • Journal of Ginseng Research
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    • v.47 no.3
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    • pp.469-478
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    • 2023
  • Background: Nitrogen (N) is an essential macronutrient for plant growth and development. To support agricultural production and enhance crop yield, two major N sources, nitrate and ammonium, are applied as fertilizers to the soil. Although many studies have been conducted on N uptake and signal transduction, the molecular genetic mechanisms of N-mediated physiological roles, such as the secondary growth of storage roots, remain largely unknown. Methods: One-year-old P. ginseng seedlings treated with KNO3 were analyzed for the secondary growth of storage roots. The histological paraffin sections were subjected to bright and polarized light microscopic analysis. Genome-wide RNA-seq and network analysis were carried out to dissect the molecular mechanism of nitrate-mediated promotion of ginseng storage root thickening. Results: Here, we report the positive effects of nitrate on storage root secondary growth in Panax ginseng. Exogenous nitrate supply to ginseng seedlings significantly increased the root secondary growth. Histological analysis indicated that the enhancement of root secondary growth could be attributed to the increase in cambium stem cell activity and the subsequent differentiation of cambium-derived storage parenchymal cells. RNA-seq and gene set enrichment analysis (GSEA) revealed that the formation of a transcriptional network comprising auxin, brassinosteroid (BR)-, ethylene-, and jasmonic acid (JA)-related genes mainly contributed to the secondary growth of ginseng storage roots. In addition, increased proliferation of cambium stem cells by a N-rich source inhibited the accumulation of starch granules in storage parenchymal cells. Conclusion: Thus, through the integration of bioinformatic and histological tissue analyses, we demonstrate that nitrate assimilation and signaling pathways are integrated into key biological processes that promote the secondary growth of P. ginseng storage roots.

Vaccinium angustifolium Root Extract Suppresses FcεRI Expression in Human Basophilic KU812F Cells.

  • Shim, Sun Yup;Lee, Kyung Dong;Lee, Mina
    • Preventive Nutrition and Food Science
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    • v.22 no.1
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    • pp.9-15
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    • 2017
  • Vaccinium angustifolium, commonly known as the lowbush blueberry, is a rich source of flavonoids, with which various human physiological activities have been associated. The present study focuses on the investigation of the effect of the methanolic extract of V. angustifolium root extract (VAE) on high affinity immunoglobulin E receptor ($Fc{\varepsilon}RI$) ${\alpha}$ chain antibody (CRA-1)-induced allergic reaction in human basophilic KU812F cells. The total phenolic content of VAE was found to be $170{\pm}1.9mg$ gallic acid equivalents/g. Flow cytometry analysis revealed that the cell surface expression of $Fc{\varepsilon}RI$ was suppressed in a concentration-dependent manner upon culture with VAE. Reverse-transcriptase polymerase chain reaction analysis showed that the mRNA level of the $Fc{\varepsilon}RI$ ${\alpha}$ chain was reduced in a concentration-dependent manner as a result of VAE treatment. Western blot analysis revealed that the protein expression of $Fc{\varepsilon}RI$ and the phosphorylation of extracellular signal-regulated kinases (ERK) 1/2 were concentration-dependently inhibited by VAE. We determined that VAE inhibited anti-CRA-1-induced histamine release, in addition to the elevation of intracellular calcium concentration ([$Ca^{2+}$]i), in a concentration-dependent manner. These results indicate that VAE may exert an anti-allergic effect via the inhibition of calcium influx and histamine release, which occurs as a result of the down-regulation of $Fc{\varepsilon}RI$ expression through inhibition of ERK 1/2 activation.