• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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• pp.44-44
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• 1999

Yeast cytochrome c peroxidase (CcP) was cloned and overexpressed in E. coli, and purified by a Ni$^{2＋}$-affinity column. HoloCcP was obtained by reconstituting apoCcP with Mn$^{3+}$-protoporphyrin IX (MnPP). Electron paramagnetic resonance (EPR) spectra of spin-labeled holoCcP showed a slightly more immobilized signal than spin-labeled apoCcP.(omitted)

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권5호
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• pp.432-443
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• 2005

Microarray technology has contributed Significantly to the understanding of bacterial genetics and transcriptional regulation. One neglected aspect of this technology has been optimization of microarray-generated signals and quality of generated information. Full genome microarrays were developed for Clostridium acetobutylicum through spotting of PCR products that were designed with minimal homology with all other genes within the genome. Using statistical analyses it is demonstrated that Signal quality is significantly improved by increasing the hybridization volume. possibly increasing the effective number of transcripts available to bind to a given spot, while changes in labeled probe amounts were found to be less sensitive to improving signal quality. In addition to Q-RT-PCR, array validation was tested by examining the transcriptional program of a mutant (M5) strain lacking the pSOL1 178-gene megaplasmid relative to the wildtype (WT) strain. Under optimal conditions, it is demonstrated that the fraction of false positive genes is 1% when considering differentially expressed genes and 7% when considering all genes with signal above background. To enhance genomic-scale understanding of organismal physiology, using data from these microarrays we estimated that $40{\sim}55%$ of the C. acetobutylicum genome is expressed at any time during batch culture, similar to estimates made for Bacillus subtilis.

• 한국광학회지
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• 제19권2호
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• pp.103-107
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• 2008

기존 OCT 시스템의 Michelson 간섭계와 다르게 간섭신호가 프로브 끝단에서 유도되어 기준신호와 샘플신호가 동일한 경로를 통해 진행하는 공통경로 OCT 시스템을 제작하였다. 최적의 기준신호가 생성되도록 하기 위해 부분반사 프로브(Probe)의 굴절률을 최적화하였고 생체 샘플의 이미지 획득이 가능하도록 프로브의 끝단에서 초점이 맺히도록 볼록 렌즈형 프로브를 제작하였다. 이를 통해서 실제 샘플의 2차원 이미지의 획득이 가능하였다.

• 한국전기전자재료학회논문지
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• 제35권4호
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• pp.412-417
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• 2022

Capacitive-type humidity sensors with a high sensitivity and fast response/recovery times have attracted a great attention in non-contact respiration biological signal monitoring applications. However, complicated fabrication processes involving high-temperature heat treatment for the hygroscopic film is essential in the conventional ceramic-based humidity sensors. In this study, a non-toxic ceramic/metal halide (BaTiO₃(BT)/NaCl) humidity sensor was prepared at room temperature using a solvent-free aerosol deposition process (AD) without any additional process. Currently prepared BT/NaCl humidity sensor shows an excellent sensitivity (245 pF/RH%) and superior response/recovery times (3s/4s) due to the NaCl ionization effect resulting in an immense interfacial polarization. Furthermore, the non-contact respiration signal variation using the BT/NaCl sensor was determined to be over 700% by maintaining the distance of 20 cm between the individual and the sensor. Through the AD-fabricated sensor in this study, we expect to develop a non-contact biological signal monitoring system that can be applied to various fields such as respiratory disease detection and management, infant respiratory signal observation, and touchless skin moisture sensing button.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.265-268
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• 1995

Signal averaging technique to improve signal-to-noise ratio has widely been used in various fields, especially in electrophysiology. Estimation of the EP(evoked potential) signal using the conventional averaging method fails to correctly reconstruct the original signal under EEG(electroencephalogram) noise especial]y when the latency times of the evoked potential are not identical. Therefore, a technique based on the bispectrum averaging was proposed for recovering signal waveform from a set o noisy signals with variable signal dalay. In this paper an improved bispectrum estimation technique of the RP signal is proposed using a confidence thresholding of the EP signal in frequency domain in which energy distribution of the EP signal is usually not uniform. The suggested technique is coupled with the conventional bispectrum estimation technique such as least square method and recursive method. Some results with simulated data and real EP signal are shown.

• 대한의용생체공학회:의공학회지
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• 제5권2호
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• pp.133-142
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• 1984

The EMG signal can be considered as a signal source that expresses the intention of man because it is a electrical signal generated when the man contracts muscles. For proportional control of prostheses, the control signal proportional to the mousle contraction level must be estimated. Typically a foul-wave rectifier and low-pass filter are used to estimate the proportional control signal from the EMG signal. In this paper, it is proposed to use a logarithmic transformation and a linear minimum mean square error estimator. A logarithmic transformation maps the myoelectric signal into an additive control signal-plus-noise domain and the Kalman filter is used to estimate the control signal as a linear minimum mean square error estimator. The performance of this estimator is verified by the computer simulation and the estimator is applied to the EMG obtained from the biceps brachii muscle of normal subjects.

• 센서학회지
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• 제20권2호
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• pp.107-113
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• 2011

LSPR(Localized Surface Plasmon Resonance) sensor measures the refractive index change on the sensor surface. The detection of biological reaction with the unknown refractive index needs to be converted into the signal sensitivity for the refractive index change for comparison with other measurements. To find the signal sensitivity, the three steps of signal processing are proposed, which are signal modeling, signal calibration and signal normalization of LSPR sensor. The detected signal of biotin-streptavidin interaction has been converted into unit of [RU](Resonance Unit) using the proposed method. The converted signal directly can be compared with the other sensors including commercialized one.

• 센서학회지
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• 제12권3호
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• pp.121-127
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• 2003

본 논문에서는 포터블 뇌파 바이오피드백시스템을 위한 전치증폭부 및 디지털 신호처리부의 하드웨어 구현에 대한 연구를 수행하였다. 뇌파의 특성을 고려하여 외부 잡음을 제거할 수 있는 뇌파 획득용 전치증폭부를 구현하였다. 측정된 뇌파에는 안전도, 근전도, 심전도 등의 신호들이 포함되어 있으며 이들은 뇌파 분석에 방해가 된다. 따라서 이러한 신호들을 제거하기 위하여 적응여파기 알고리즘을 수행하고 전치증폭부를 실시간으로 구동하는 디지털신호처리부를 구현하였다. 시뮬레이션 파형과 실제 뇌파를 적용한 실험결과를 통하여 개발된 시스템의 성능을 확인 할 수 있었으며 휴대형 뇌파바이오피드백 시스템에 적용 가능함을 확인하였다.

• Journal of Applied Biological Chemistry
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• 제53권2호
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• pp.105-107
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• 2010

To overcome the limitation of E. coli expression system such as inclusion body formation and disulfide bond failure, we tried to express the heterologous protein as a secreted form. We adopted agarase signal peptide (ASP; 23 amino acid residues) from Agarivorans albus YKW-34 which is one of marine bacteia. When we used ASP to express $\beta$-agarase, about 42% activity was detected in media.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.111-111
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• 2001

The relationship between selenium and signal molecules is not well elucidated yet. It was found that physiological concentration of selenite, less than 3 $\mu$M, reduced ASKl activity and induced of PI3-Kinase/Akt pathways in HT1080 cells. Duration of these signal molecules by selenite was much longer than that by growth factors and other stresses. The longer duration time of these signal molecules may be important to maintain normal functions against stresses.(omitted)