• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.104-108
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• 2015

Al thin films were deposited on TiN/Si(100) via metal-organic chemical vapor deposition using N-methylpyrrolidine alane as a precursor. Characterization of the deposited films were investigated with SEM, XRD, ${\alpha}$-step, AFM, 4-point probe. The early stage of Al thin film deposition was analyzed by in-situ surface reflectance measurement with laser and photometer apparatus. The surface reflectance were changed greatly during the initial 30~40 seconds. There were two increases and two decreases in the surface reflectance, thus the sequence of Al films were deposited at 8 significant points of the surface reflectance change. Surface topograph and cross-sectional view of each film were analyzed with SEM. Al films were grown in the complex mechanism of Volmer-Weber and Stranski-Krastanov process.

• Journal of Mechanical Science and Technology
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• v.19 no.8
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• pp.1576-1581
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• 2005

Generally, the optical components are fabricated by grinding, lapping, and polishing. And, those processes take long time to obtain such a high surface quality. Therefore, in the case of large optical component, the on-machine inspection (OMI) is essential. Because, the work piece is fragile and difficult to set up for fabricating and measuring. This paper is concerned about a swing-arm method for measuring surface profile of large optical concave mirror. The measuring accuracy and uncertainty for suggested method are studied. The experimental results show that this method is useful specially in lapping process with the accuracy of $3\~5\;{\mu}m$. Those inspection data are provided for correcting the residual figuring error in lapping or polishing processes.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.45-49
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• 2005

현대 산업사회의 제조업에서는 생산을 가장 중요시하고 있지만 안전에 관한 의식도 많은 관심의 대상이 되고 있다. 사고예방을 위한 지속적인 노력에 따라 사고 건수는 점차 줄어들고 있으나 치명적인 중대 산업사고는 오히려 증가하여 산업재해로 인한 사망자 수는 줄어들지 않고 있다. 이와 같은 상황에 따라 중대 산업사고를 예방하기 위한 수단으로 공정안전관리제도를 도입하여 시행하고자 하고 있다. 하지만 일반 제조업에서는 화공안전의 경우와 같은 공정안전을 측정하는 방법이 아직 미흡한 실정이다. 따라서 본 연구에서는 제조업의 공정을 안전에 대한 관점에서 분석하고 효율적으로 공정별로 측정하여 관리할 수 있는 기법을 제시하고자 한다. 제안되는 기법은 안전에 대한 항목은 기업의 관리자들을 통한 AHP 가중치를 결정하고 각 공정을 정규화된 행렬을 이용하여 제안하였다.

• BMB Reports
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• v.29 no.6
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• pp.489-492
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• 1996

A number of anticancer-chemotherapeutic agents induce cell death through the process of apoptosis. Effects of echinomycin, an anticancer agent on cancer progression, were investigated in P388 murine leukemia cells. First, according to the results of cytotoxicity measurement. $IC_{50}$ of echinomycin was 1.12 nM, a relatively lower value than the other examined anticancer agents, mitomycin-C and etoposide Second, the DNA fragmentation assay for echinomycin-treated cells exhibited that echinomycin was able to induce apoptosis in a shorter period of time and with a lower dose than mitomycin-C or etoposide. The data of DNA fragmentation were quite comparable to those of cytotoxicity measurement. Finally we showed that mitogen-activated protein (MAP) kinase, a key protein in cell mitosis, was translocated into the nucleus from the cytosol after treatment with echinomycin. These findings suggest that a MAP kinase-related process may be involved in apoptosis induced by echinomycin.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.2
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• pp.104-109
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• 2011

I present a method of aspheric surface profile measurement using 2nd derivative of local area profile. This method is based on the principle of curvature sensor which measures the local 2nd derivative under test along a line. The profile is then reconstructed from the data on the each point. Unlike subaperture-stiching method and slope detection method, 2nd derivative method has strong points from a geometric point of view in measuring the aspheric surface profile. The second derivative terms of surface profile is an intrinsic property of the test piece, which is independent of its position and tip-tilt motion. The curvature is measured at every local area with high accuracy and high lateral resolution by using White-light scanning interferometry.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.1
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• pp.3-8
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• 2008

This paper reports some experimental results of cylindrical external grinding using CBN wheels. Many experimental studies for surface grinding have been done, but not for the cylindrical grinding due to the difficulty of grinding force measurement. In this paper a new experimental device has been proposed for the grinding force measurement in cylindrical grinding. The cylindrical grinding experiments were carried out at various grinding conditions with several CBN grinding wheels. The experimental results indicate that the CBN wheels with smaller grains result in the higher grinding forces in both SCM415 and STD11 workpieces. The grinding forces of all wheels were proportional to the infeed speeds and the difference of each wheels was prominent at high infeed speed for SCM415.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.2
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• pp.68-74
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• 2013

In this paper, an average surface roughness, $R_a$, was measured by optical measurement and its mathematical model according to spindle speed and feedrate was obtained by least square method. Also, its result is compared and investigated with real measured average surface roughness. The optical measurement of surface roughness is performed by CLSM(confocal laser scanning microscope) and the captured HEI(height encoded image) data is used as an original data for the generation of average surface roughness and its mathematical plane or contour surface of surface roughness. Using this polynomial model with two independent variables, the behavior of an average surface roughness is investigated and analyzed with an experimental modeling of least square algorithm. And it can be used for the prediction of $R_a$ in different condition of machining.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.451-455
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• 1997

The partial discharge has been blown as the chief breakdown of power equipments. The analysis and the recognition is much difficult because the partial discharge signal is very small and has complex aging pattern. Recently, insulation aging diagnosis based on pattern of phase(Ф), partial discharge magnitude(q), number(n) has been very important. Owing to depreciate the reappearance of aging progress at the electrical tree pattern and to be difficult to analyze visually, the study on partial discharge pattern is suggested to normalizing analysis method of partial discharge signals. This parer is purposed on prediction of life-time measurement of cv-cable, on decision of risk degree with normalization and real-time measurement of partial discharge signals for aging diagnosis of cv-cable. As normalizing the aging signals of electrical tree in cv-cable, it is able to confirm risk degree of insulation material with the distribution of Ф-q-n and recognize the process of aging pattern using neural network.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.10
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• pp.653-656
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• 2014

$Cs_3Sb$ photocathode was formed by newly developed process and successive in-situ lighting devices were fabricated in a process chamber. R, G, and B phosphors were applied on the anode plate, respectively. Major parameters such as brightness, power consumption, and efficacy were measured. The wavelength of LED excitation source was 450 nm. Both high power and low power modes were applied in the measurement. Measurement values were clearly differentiated by the voltage application modes. The measured values of each parameter was good enough to be applied for general lighting source. The results showed that $Cs_3Sb$ photocathode formed in atmospheric conditions was functioning as good as the photocathode formed in UHV conditions, and thus it could be applied to advanced lighting devices.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.268.1-268.1
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• 2013

Immobilization of conducting nanoparticles on a nanogap comprising two electrodes spaced at a distance comparable to the particle size can be used as a simple and sensitive method of detecting the particles. In this work, we have examined the performance of the nanogap devices in the measurement of metallic nanoparticles, particularly gold nanoparticles (Au NPs). Detection of pM-level Au NPs in an aqueous suspension was quite straightforward irrespective of the existence of non-conducting materials. Speed of detection or the time necessary for the completion of the measurement, however, was strongly dependent upon the immobilization process. Active trapping process was found to be much more efficient and also effective in the detection of nanoparticles than its passive counterpart.