• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 초전도 자성체 연구회
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• pp.50-54
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• 2003

The output characteristics of thin film NiO/NiFe bilayered magnetoresistive device have been measured as a function of the direction of external magnetic field. Each layer was fabricated by rf magnetron sputtering method, and especially, the under layer, NiO, was fabricated under the in-situmagnetic field of about 1000Oe. The magnetoresistive devices were designed with the angle of 45degree between the direction of current of the device pattern and the induces magnetic field in the NiO film layer. The output of the devices had a good linearity when the devices were placed on the external magnetic field perpendicular to induced field direction and also 45 degree with the currenr path direction.

• 대한전기학회논문지
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• 제38권1호
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• pp.22-28
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• 1989

This paper describes error estimate mothod for adaptive finite element analysis of two dimensional electrostatic and magnetostatic field problems. To estimate the local errors, divergence theorem is used for electrostatic field and Ampere's circuital law for magnetostatic field. To confirm the effectiveness of the proposed error estimators, adaptive finite element computations are performed using the proposed error estimators. The rates of convergence of global errors are comparable with those of existing adaptive finite element schemes which make use of field continuity conditions between element boundaries. This algorithm of error estimate can be easily implemented because of its simplicity. Especially, when the value of charge in electrostatic field and the value of current in magnetostatic field are to be figured out, this method is considerded to be preferable to other approaches.

• 한국전기전자재료학회논문지
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• 제11권1호
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• pp.26-32
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• 1998

We have studied how the characteristics degradation between effective mobility and field effect mobility of gate channel in p-MOSFET's affects the gate channel length being follow by increased stress time and increased drain-source voltage stress. The experimental results between effective and field-effect mobility were analyzed that the measurement data are identical at the point of minimum slope in threshold voltage, the other part is different, that is, the effective mobility it the faster than the field-effect mobility. Also, It was found that the effective and field-effect mobility. Also, It was found that the effective and field-effect mobility of p-MOSFET's with short channel are increased by decreased channel length, increased stress time and increased drain-source voltage stress.

• 전기학회논문지
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• 제60권2호
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• pp.301-308
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• 2011

This paper deals with the coupled electromagnetic-mechanical field analysis for short-circuit electromagnetic force of the dry-type transformer. The short-circuit currents are calculated using external circuit in accordance with short-circuit test equipment. According to short-circuit current, the generated magnetic leakage flux density in dry-type transformer model is calculated by finite element method. The radially-directed electromagnetic forces in windings are calculated using electromagnetic field analysis and then axially-directed electromagnetic forces in windings are calculated using electromagnetic-mechanical field analysis. The calculated axially-directed electromagnetic forces in high voltage winding are compared to those of measured ones and showed good agreement with experimental results.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.559-564
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• 2004

This paper deals with the device for measuring the time-varying magnetic fields and induced voltages caused by lightning discharges. The two magnetic field measuring systems were designed and made. One consists of the loop-type magnetic field sensor with the active integrator operated by a differential amplifier. The other consists of the loop-type magnetic field sensor and Labview software. The loop-type magnetic field sensor detects the time derivative of the magnetic field being measured, and the signal detected is integrated by the Labview software. As a consequence, from the calibration experiments, the frequency bandwidth of the full measuring system ranges from 400 [Hz] to 1 (MHz) and the response sensitivity are 0.98 (mV/nT) and 22 (mV/nT) for the magnetic field sensor of 2 turns and 6 turns, respectively. Also, the results obtained by the two measuring devices well agreed with each other.

• 대한전기학회논문지
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• 제38권6호
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• pp.401-415
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• 1989

A simple but accurate analytical model for the lateral channel electric field in gate-offset structured Lightly Doped Drain MOSFET has been developed. Our model assumes Gaussian doping profile, rather than simple uniform doping, for the lightly doped region and our model can be applied to LDD structures where the junction depth of LDD is not identical to the heavily doped drain. The validity of our model has been proved by comparing our analytical results with two dimensional device simulations. Due to its simplicity, our model gives a better understanding of the mechanisms involved in reducing the electric field in the LDD MOSFET. The model shows clearly the dependencies of the lateral channel electric field on the drain and gate bias conditions and process, design parameters. Advantages of our analytical model over costly 2-D device simulations is to identify the effects of various parameters, such as oxide thickness, junction depth, gate/drain bias, the length and doping concentration of the lightly doped region, on the peak electric field that causes hot-electron pohenomena, individually. Our model can also find the optimum doping concentration of LDD which minimizes the peak electric field and hot-electron effects.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.519-523
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• 2000

Using plasma-enhanced chemical vapor deposition (PECVD), carbon thin film as electron field emitter were fabricated. These carbon thin film were deposited on Si(100) substrate at several RF power. These film were estimated by raman spectroscopy, scanning electron microscopy, and field emission. The field electron emission property of these carbon thin film was estimated by a diode technique. As the result, we observed that the field emission properties of these films were promoted by higher RF power. These results are explained as change of surface morphology and structural properties of carbon thin film

• 대한전기학회논문지
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• 제45권1호
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• pp.24-29
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• 1996

Magnetic field theories for the design of highly homogeneous magnet are introduced and a nonlinear optimization method for the design of actively shielded superconducting magnet is presented. The presented design method can optimize both main coil and shielding coil simultaneously by setting constraints on stray field intensity at a specified distance from the magnet center. A 2-Tesla actively shielded superconducting magnet, with 90cm bore diameter, is designed using the presented method. The field homogeneity is 2ppm/30cm DSV and the 5 gauss stray field contour is within 4m axially and 3m radially from the magnet center. (author)., 7 refs., 6 figs., 3 tabs.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권2호
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• pp.97-102
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• 2004

The objective of this survey is to characterize personal magnetic field exposure of the general population in Korea. Participants for the survey on magnetic field exposure were selected randomly in some occupations. Those wore the magnetic field meter for about 25∼28 hours and the measured data were stored in the meter. In this first step survey, the number of participant is 244 and for the second step, about 400 participants will be surveyed in the near future. The statistics of the 24-hour exposure data are the major concern of this survey. However the survey provided the opportunity to analyze exposures corresponding to different types of activities. It was analyzed by separating periods of time corresponding to the following activities: entire 24-hour period, in bed, at work and by occupation. Therefore the database will be able to be established to analyze the status of personal magnetic field exposure and safety.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.61-65
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• 2003

A magnetic field sensor is fabricated with superconducting ceramics system The prepared material shows the superconductivity at about 95K. The sensor at liquid nitrogen temperature shows the increase in electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor is changed from zero to a value more than $100{\mu}V$ by the applied magnetic field. The change in electrical resistance depends on magnetic field. The sensitivity of this sensor is 2.9 ohm/T. The increase in electrical resistance by the magnetic field is ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material.