• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.29-35
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• 2020

Car inspection systems are regularly carried out by the state to ensure the safety and emission status of cars, thereby improving the safety and quality of life by reducing fine dust and greenhouse gases that are the main culprits of vehicle defects and air pollution. These automobile inspections are largely divided into either regular or comprehensive inspections. This study analyzed the smoke measuring probes used in the lug - down 3 mode. In the previously issued paper "Improvement of Soot Probe Efficiency for Automotive Emission Measurement," an improved smoke measurement probe(B) improved on the problems that arise from the current smoke measurement probe (A). In this study, a technique that can improve the probe's inhalation efficiency over the improved (B) probes was applied to probes (C). Probe (C) involves a structure designed close to the center of the circumference of the exhaust pipe, and the suction efficiency was improved by adding a variable center unit.

• Journal of Sensor Science and Technology
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• v.21 no.2
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• pp.156-166
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• 2012

Over the past 15 years productive BCI research programs have arisen. Current mainstream EEG electrode setups permit efficient recordings but most of electrodes has the disadventages of need for skin preparation and gel application to correctly record signals. The new gel-free probe was adapted for EEG recording and it can be fixed to the scalp with the micro needle without neuro-gel. It use standard EEG cap for wearing electrodes on scalp so it is compatible with standard EEG electrodes. A comparison between electrode characteristics is achieved by performing simultaneous recordings with the gel electrodes and gel-free probe placed in parallel scalp positions on the same anatomical regions. The quality of EEG recordings for all two types of experimental conditions is similar for gel-electrodes and gel-free probe. Subjects also reported not having special tactile sensations associated with wearing of gel-free probes. According to our results, it is expected that gel-free probe can be adapted to BCI, BMI(Brain Machine Interface), HMI(Human Machine Interface) because of its simple application and comfortable wearing process.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.5
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• pp.398-408
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• 2007

For better evaluation of material thickness by using the reflection type pulsed eddy current method, various probe models are designed and their response signals, characteristics, and sensitivities to thickness variation are investigated by a numerical analysis method. Since the sensor needs to detect magnetic fields from eddy currents induced in a test material, not from the exciter coil, two types of models that are shielded by the combination of copper and ferrite and only by ferrite are considered. By studying response signals from these shielded probe models, the peak value and the zero crossing time are selected as useful signal features for the evaluation of material thickness. Investigation of sensitivities of these two features shows that the sensitivity of peak value is more useful than that of zero crossing time and that the probe shielded only by ferrite gives much better sensitivity to thickness variation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.5
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• pp.154-161
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• 2009

Recently, as many functional blocks are integrated on a small area the high speed integrated circuits emerge as a critical electromagnetic interferer which causes mal-function of adjacent circuitries and lowers the sensitivity of the wireless receivers. Therefore, it is necessary to devise an precise analyzing tool to pinpoint the major electromagnetic noise contributor among the internal circuit blocks of high speed IC's. This paper presents the design, fabrication, and measurement results of the high resolution magnetic field probe which can measure the current density on the IC surface. In order to achieve the high resolution, the magnetic field probe is fabricated using 3-metal semiconductor process so that its thickness is reduced by 10% than that of conventional works. Through the magnetostatic analysis and EM simulation, spatial resolution and sensitivity to the nonmagnetic field components are analyzed. Experimentally, it is found that the fabricated probe can measure the current density on the IC surface with $210{\mu}m$-spatial-resolution.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.5
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• pp.29-35
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• 1999

Inductively coupled plsama etching of platinum thin film was studied using $O_2$ addition to $Cl_2$/Ar gas plasma. In this study, Pt etching mechanism was investigated with Ar/$Cl_2$ /$O_2$ gas plasma by using XPS and QMS. Ion current density was measured with Ar/$Cl_2$ /$O_2$ gas plasma by using single Langmuir probe. It was confirmed by using QMS and single Langmuir probe that Cl and Ar species rapidly decreased and ion current density was also decreased with increasing $O_2$ gas ratios. These results implied that the decrease of Pt etch rate is due to the decrease of reactive species ans ion current density with increasing $O_2$ gas mixing ratios. A maximum etch rate of 150nm/min and the oxide selectivity of 2.5 were obtained at Ar/$Cl_2$ /$O_2$ flow rate of 50 seem, RF power of 600 W, dc bias voltage of 125 V, and the total pressure of 10 mTorr.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.2
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• pp.97-104
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• 2001

The effects of the position of potential probe on the measurements of the ground resistance in the fa11-of-potential method are described. The ground resistance is theoretically calculated by applying the 61.8[%] rule, and then the potential probe is located on the straight line between the grounding electrode to be measured and the current probe. However, sometimes the grounding electrode to be measured and the measuring potential and current probes in on-site test might not be arranged on the straight line with adequate distance because there are building, roadblock construction and other establishments. Provided that the grounding electrode to be measured and the measuring potential probes are out of position on the straight line, the measurement of the ground resistance classically falls into an error and the measured ground resistance should be corrected. In this work, measurements were focused on the grounding electrode system made by the ground rods of 2.4 m long. The measuring error was increased with increasing the angle which is made by the 3-points of the grounding electrode to be measured, the potential anti current probes, and it was a negative. That is, all of the measured ground resistances ware less than the true ground resistance.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.145-148
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• 1989

Plasma diagnostics using Langmuir Probe is of wide application because of its simplicity in measurement of electron temperatures and densities. Current methods using simple circuit and analog meters, however, have troubles when they are applied to time-varying or thermal plasmas. To overcome these problems and expand the area of applicability, we have designed fast electronic voltage sweeping circuit in which we can detect digital data. Diagnostics using our digital Langmuir Probe is performed in various kinds of plasmas and the results are shown. Our method can be applied to measuring electron temperature and density of high temperature or time-varying plasmas. And we expect further knowledge of each state of plasma.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.301-306
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• 2008

Various sensors such as capacitive probe, high frequency current transformer (HFCT), and acoustic emission (AE) probe were applied to a cast resin dry type transformer for partial discharge detection. We designed and fabricated a wideband low-noise amplifier having a gain of 40[dB]. From the experiment which was carried out in the same transformer, the sensitivities were 7.16[mV/pC] for capacitive probe, 3.8[mV/pC] for HFCT, and 17.9[mV/pC] for AE probe.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1388-1389
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• 2006

금속의 전기비저항 측정은 4단자 방법, van der Pauw 방법, Four Point Probe(FPP) 방법 등이 있으며, 이들의 정확한 측정방법을 고찰하고, 그 중 FPP 방법에 의한 비저항의 두께효과를 비교 분석하기 위하여 비자성 금속 SUS 316을 두께별로 가공한 후 실험하였다. 그 결과 4단자 및 van der Pauw 방법으로 측정된 도전율은 각각 2.273 %IACS으로 나타났으며, FPP방법으로 측정된 도전율은 probe spacing 5.0 mm, dc current 10 A에서 시료의 두께가 2 mm일 때 2.288 %IACS, 3 mm일 때 2.271 %IACS로서 상기 두 방법으로 측정한 결과와 0.5 %이내에서 일치하였으나, 시료가 5mm 및 11 mm 에서는 매우 큰 오차를 나타냈다.

• Geomechanics and Engineering
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• v.33 no.3
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• pp.291-299
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• 2023

Monitoring contaminants in waste landfills on a seabed is important because the leachate affects the marine ecosystem and facility stability. The objective of this study is to optimize a time-domain reflectometry (TDR) probe using different coating materials and several electrodes to estimate contaminants in saline soil. Copper concentrations ranging from 0 mg/L to 10 mg/L were mixed in 3% salinity water to simulate contaminants in the ocean environment. Epoxy, top-coat, and varnish were used as coating materials, and two to seven electrodes were prepared to vary the number and arrangement of the electrodes. Test results showed that the varnish stably captured the increase in copper concentration, while the other coating materials became insensitive or caused leakage current. In addition, a TDR probe with more electrodes exhibited stable and distinct electromagnetic signals. Thus, the TDR probe with seven electrodes coated with varnish was effectively used to estimate contaminants in saline soil.