• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.195-199
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• 1995

본 연구에서는 피부전기반사를 이용하여 각성도를 측정하기 위한 측정 시스템을 구성하고 이를 이용하여 피부 전기활동의 변화가 뇌파를 동시에 측정하여 각성수준의 변화에 따른 세 측정 요소간의 상관관계를 검토하고 측정에 따른 문제점들을 분석하여 각성도 측정 및 평가와 모니터 개발 을 위한 기초적인 연구를 하였다. 분석 결과 기존의 피부임피던스 만을 이용한 수면상태 판정은 불완전하며 피부임피던스 반사도 포함하면 더욱 정확한 판정을 할 수 있슴을 밝혔다.

• Journal of the Ergonomics Society of Korea
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• v.16 no.2
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• pp.15-27
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• 1997

Brain potential is described using the mesocolumnar activity defined by averaged firings of excitatory and inhibitory neuron of neocortex. Lagrangian is constructed based on SMNI(Statistical Mechanics of Neocortical Interaction) and then Euler Lagrange equation is obtained. Excitatory neuron firing is assumed to be amplitude- modulated dominantly by the sum of two modes of frequency .omega. and 2 .omega. . Time series of this neuron firing is calculated numerically by Euler Lagrangian equation. I .omega. L related to low frequency distribution of power spectrum, I .omega. H hight frequency, and Sd(standard deviation) were introduced for the effective extraction of the dynamic property in the simulated brain potential. The relative behavior of I .omega. L, I .omega. H, and Sd was found by parameters .epsilon. and .gamma. related to nonlinearity and harmonics respectively. Experimental I .omega L, I .omega. H, and Sd were obtained from EEG of human in rest state and of canine in deep sleep state and were compared with theoretical ones.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.138-146
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• 2012

Using Shear-free Ship wake theory it was predicted the detectable submarine's turbulent wake on the sea surface was about 12km long when there was no breaking waves on the sea surface. It means that there are sufficient detectable turbulent kinetic energies on the sea surface as well as in the water. In this paper, we have proposed some concepts of non acoustic anti-submarine surveillance systems; SAR for sea surface surveillance, LIDAR for sub-surface surveillance and propelled gliders for under -water surveillance.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1609-1611
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• 2003

This paper presents the results on the development of capacitive sensor for the diagnosis of electrical insulating oil, widely used for power transformer. To survey the dielectric properties of the new and used mineral insulating oil, we utilized the highly precise measuring system of KRISS. And the results were used to determine the design factors of the sensor. To evaluate the operational and the hysteresis characteristics of the sensor, we constructed a test chamber, including dielectric property measuring system. Through the results we could confirm the superior characteristics of the newly developed sensor.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.977-978
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• 2007

The phase angle which is mainly depend on time constant $\tau$ of the calculable 10 A and 0.1 ${\Omega}ac/dc$ resistor has been analysed. The low values of resistors are usually inductive and time constant $\tau$ very large compare to high values of resistors. The numerical analysis has been shown that the time constant $\tau$ becomes zero when introduce the compensation capacitance geometrically to the resistive coil with proper dimension. As a result a very low phase angle can be achieved within the realizable dimensions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.439-442
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• 2003

The test method of ASTM E 756 and JIS G 0602 to estimate vibration-damping properties is presented. Measurement method depending on specimen support, exciting method and calculation method for loss factor is used. Half-power bandwidth method and vibration decay method is used in the calculation method for loss factor, and Young's modulus is decided by geometric character and density for specimen and resonance frequency. Vibration measurement sensor is compared by using non-contact displacement detector, velocity detector and accelerometer. The cause of measurement error is also presented.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.603-604
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• 2005

A precise ratio transformer which is used to a ratio arm of a precise impedance measurement bridge at low frequencies was developed. The developed ratio transformer has the ratio taps of 1:1, 2:1, $\cdots$, to 10:1 in order to measure the primary impedance standards by substitution and special winding techniques for 10:1 ratio that is used frequently for impedance build up/down. The calibration results of the transformer has inphase and quadrature error of $0.073\times10^{-6}$ and $0.14\times10^{-6}$ respectively at 1.6 kHz.

• Mass Spectrometry Letters
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• v.8 no.2
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• pp.44-47
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• 2017

Isothiazolinone derivatives are widely used in consumer products as disinfectants or preservatives, but there are growing concerns about their impact on human health. Therefore, rapid screening of these biocides is very important for proper control and regulation of potentially hazardous substances. To this end, low-temperature plasma (LTP) ionization mass spectrometry (MS) was investigated to demonstrate its potential for direct and selective analysis of isothiazolinones from sprayed aerosol samples. Benzisothiazolinone (BIT) was clearly identified from a commercial fabric deodorant using LTP ionization MS and MS/MS. LTP allowed selective ionization of BIT directly from the simply sprayed aerosol sample and illustrated its potential for fast screening without sample pre-treatments. Selective nature of LTP ionization, on the other hands, implicates use of LTP ionization MS as a general screening method for specific groups of hazardous chemicals in commercial products.

• Current Applied Physics
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• v.18 no.11
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• pp.1230-1234
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• 2018

We report a new method of measuring the non-radiative recombination rate in bulk Silicon. Synchrotron timeresolved x-ray scattering (TRXS) combines femtometer spatial sensitivity with nanosecond time resolution to record the temporal evolution of a crystal lattice following intense ultrafast laser excitation. Modeling this data requires an Auger recombination time that is considerably slower than previous measurements, which were made at lower laser intensities while probing only a relatively shallow surface depth. We attribute this difference to an enhanced Coulomb interaction that has been predicted to occur in bulk materials with high densities of photoexcited charge carriers.

• Proceedings of the Korean Magnestics Society Conference
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• 1998.05a
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• pp.126-127
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• 1998