• Proceedings of the Korean Magnestics Society Conference
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• 한국자기학회 1995년도 춘계연구발표회 논문개요집
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• pp.40-41
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• 1995

• Journal of the Korean Magnetics Society
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• 제24권4호
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• pp.123-127
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• 2014

We developed a digital 3-axis flux-gate magnetometer for magnetic field signal measurement from warship during demagnetizing and degaussing processes. For the magnetometer design, we considered following points; the distance between magnetic field measurement station and magnetometer located under sea is about several 100 m, the magnetometer is exposed to magnetic field of ${\pm}1mT$ during demagnetizing process, and magnetometer is located under the sea about 30 m depth. To overcome long distance problem, magnetometer could be operated on wide input supply voltage range of 16~36 V using DC/DC converter, and for the data communication between the magnetometer and measurement station a RS422 serial interface was employed. To improve perming effect due to the ${\pm}1mT$ during demagnetizing process, magnetometer could be compensated external magnetic field up to ${\pm}1mT$ but magnetic field measuring rang is only ${\pm}100{\mu}T$. The perming effect was about ${\pm}2nT$ under ${\pm}1mT$ external magnetic field. The magnetometer was tested water vessel with air pressure up to 6 bar for the sea water pressure problems. Linearity of the magnetometer was better than 0.01 % in the measuring range of ${\pm}0.1mT$ and noise level was $30pT/\sqrt{Hz}$ at 1 Hz.

• Journal of the Korean Magnetics Society
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• 제16권4호
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• pp.211-215
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• 2006

Measurement methods in order to measure the mechanical properties nondestructively have been studied. The mechanical properties of the structural and turbine rotor steels are related with their magnetic properties. If the magnetic properties of the cold rolled carbon steel sheet (CR) for a car are measured nondestructively, its mechanical properties are analogized by their magnetic properties. And then the mechanical properties are monitored on-line by measuring the magnetic properties. We prepared three CR materials, CBQ 3060, CBQ 3041, and CBQ 3036, were prepared in order to measure their mechanical and magnetic properties. The Vickers hardness,yield strength, and tensile strength were measured by ASTM E 8M, and the reversible magnetic permeability was measured by the surface type probe. The coercivity calculated by the peak interval of reversible magnetic permeability increased linearly with the increase of Vickers hardness, yield strength, and tensile strength. The amplitude of the peak interval of reversible magnetic permeability drastically decreased when the lift-off was increased.

• Journal of the Korean Magnetics Society
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• 제16권1호
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• pp.14-17
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• 2006

[ $AIFeO_3$ ]has been studied by x-ray diffraction (XRD), vibrating sample magnetometer, Mossbauer spectroscopy. The crystal structure is found to orthorhombic with the lattice parameters being $a_0=4.983\;{\AA},\;b_0=8.554\;{\AA},\;c_0=9.239\;{\AA}$, Magnetic hysteresis curve for $AIFeO_3$ showed weakly ferromagnetic phase at room temperature and a asymmetric shape dependent on the direction of applied field at low temperature. The Curie temperature determined by the temperature dependence of magnetization is 250 K. Mossbauer spectra of $AIFeO_3$ have been taken from 4.2 K to 295 K. Isomer shift at room temperature are found to be $0.11\~0.32\;mm/s$, which is consistent with ferric state. The absorption lines widths become broader with increasing temperature, which is attributed to the Fe ions distribution of each cation site and anisotropy energy difference of each sublattice.

• Journal of the Korean Magnetics Society
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• 제7권6호
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• pp.327-333
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• 1997

We designed and constructed the high frequency magnetic characteristics measurement system to measure core loss, B-H curve, permeability of toroidal ferrite core, amorphous core and various materials for high frequency application. The system consists of universal equipments such as digitizing oscilloscope, signal generator, power amplifier, PC in order to make upgrade easily. The power source is composed of waveform synthesizer and power amplifier ranging from DC to 20 MHz, and output signal H and B from sample core are digitized by oscilloscope with sampling rate 1 GS/ s per channel. Computer controls power source and oscilloscope, reads data from oscilloscope, displays analyzed waveform and saves data with file. The entire procedures finishes within few seconds.

• Korean Journal of Psychosomatic Medicine
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• 제19권1호
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• pp.34-40
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• 2011

Objectives: The purpose of this study is to test the reliability of the Korean version of self-compassion scale (K-SCS). Methods: The total of 484 participants were included in this study. Reliability studies were conducted and internal consistency were examined. Results: The internal consistency of the K-SCS was 0.76, and test-retest reliability was 0.53. Conclusion: The K-SCS appeared to be a reliable instrument for assessing self-compassion in Korean population. If supplements further studies of the validity, this scale may be applicable in clinical trials, research, clinical practice.

• Journal of the Korean Magnetics Society
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• 제14권6호
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• pp.201-206
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• 2004

The AC-DC magnetic field standard systems were constructed for the calibration of magnetometers for low magnetic field and the tests for low magnetic field characteristics of sensors and materials. In the range of 1 mT, the expanded uncertainty of dc is 8${\times}$10$\^$-6/, ac uncertainties are 0.16% in 0.1～1 kHz, 0.26% in 1～5 kHz, and 0.44% in 5～20 kHz. We have been participated in international key comparison(KC) to achieve the equality and the mutual agreement between standard institutes for the results of calibrations and tests. KRISS participating in ac-dc magnetic flux density of KC got equal level of uncertainty results compare with the advanced nations. It confirm that measurement ability of magnetic flux density is high level in the world.

• Journal of the Korean Magnetics Society
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• 제5권5호
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• pp.900-904
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• 1995

We have developed a new torque magnetometric method for measuring the M-H hysteresis loop of a spheroid-shape magnetic material having a uniaxial anisotropy. Our torque magnetometric method gives the saturation magnetization as well as the remnant magnetization, simultaneously. A torque magnetometer having the torque sensitivity of $10^{-6}$ dyn cm could give the extreamly high sensitivity of $10^{-9}$ emu in measuring the magnetic moment, which is high enough to measure the magnetic moment of a monolayer Ni film. The accuracy of the present method was negligibly affected even at the applied fields near the coercivity where magnetization was inhomogeneous.

• Proceedings of the ESK Conference
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• 대한인간공학회 1993년도 추계학술대회논문집
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• pp.38-45
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• 1993

VDT는 저주파 대역에서 인체에 해롭다고 여겨지는 전자파를 발생시키고 있다. 선진제국에서는 VDT에 서 발생하는 전자파를 규제하기 위해 VDT 전자파 측정방법의 표준화와 안전 규제 등을 실시하고 있다. VDT와 관련한 대표적인 측정기준으로는 스웨덴의 MPR 기준이 있다. 본 연구에서는 MPR 기준에 의거 VDT의 전기장, 자기장 모두에 대해 거리별, 방향별, 높이별 세기를 측정하였다. 또한 VDT 전자파의 상대적 세기를 알아보기 위해 다른 전기제품인 전기담요, 헤어드리이어 등에 대한 비교측정도 수행하였 으며, 보안경의 전자파 차폐효과도 측정하였다. 측정결과, VDT 전기장은 전면에서 세기가 가장 크며, 후면으로 갈수록 작아지는 것으로 나타났으며, 자기장은 ELF 대역은 양측면에서, VLF 대역은 전면에서 그 크기가 가장 큰것으로 나타났다. 전기제품과의 비교에서는 VDT의 전기장, 자기장은 전기담요, 헤어 드리이어 등에 비해 크지 않은 것으로 나타났으며, 보안경은 접지해서 쓸때만 전기장 차폐효과가 큰것 으로 나타났다.

• Journal of the Korean Magnetics Society
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• 제7권6호
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• pp.334-339
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• 1997

센서는 어떤 물리 .center dot. 화학적량을 다른 물리 .center dot. 화학적량으로 변환시키는 기능의 소자를 통칭하는 용어로써 그 범위가 매우 넓으며, 현대 산업사회에서 전기 .center dot. 전자공학의 반전과 더불어 센서가 더욱 중요시되고 있다. 특히 대부분의 센서가 피측정 물리 .center dot. 화학적량을 전기적 신호로 변화 시키는 기능으로 정밀측정, 생산자동화 및 자동제어등에 다양하게 사용되고 있다. 센서는 원리적 측면에서의 분류와 센서의 기능적 측면으로 분류방법이 있다. 센서 관련 학문적 연구면에서 보면 센서의 원리적 측면에서의 접근이 용이하며 센서를 사용하는 산업체나 사용자의 입장에서는 센서의 기능적 측면 즉 피측정 물리 .center dot. 화학적량의 종류에 따른 분류가 편리하다.