• KIPS Transactions on Software and Data Engineering
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• v.11 no.12
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• pp.525-530
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• 2022

Although the iterative closest point (ICP) algorithm has been widely used to align two point clouds, ICP tends to fail when the initial orientation of the two point clouds are significantly different. In this paper, when two triangular meshes A and B have significantly different initial orientations, we present an algorithm to align them. After obtaining weighted centroids for meshes A and B, respectively, vertices that are likely to correspond to each other between meshes are set as feature points using the distance from the centroid to the vertices. After rotating mesh B so that the feature points of A and B to be close each other, RMSD (root mean square deviation) is measured for the vertices of A and B. Aligned meshes are obtained by repeating the same process while changing the feature points until the RMSD is less than the reference value. Through experiments, we show that the proposed algorithm aligns the mesh even when the ICP and Go-ICP algorithms fail.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.328.1-328.1
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• 2014

MOSFET degradation의 대부분은 hot-carrier injection에 의한 interface state (Dit)의 생성에서 비롯되며 따라서 본 연구에서는 신뢰성에 대한 한 가지 방법으로 Charge pumping method를 이용하여 MOSFET의 interface trap(Dit)의 변화를 측정하였다. 소스와 드레인을 ground로 묶고 게이트에 펄스를 인가한 후 Icp를 측정하여 Dit를 추출하였다. 온도를 293~343 K까지 5 K씩 가변했을 때 293K의 Icp(${\mu}A$)는 0.12 nA 313 K는 0.112 nA 343 K는 0.926 nA이며 Dit (cm-1/eV-1)는 $1.61{\times}10^{12}$ (Cm-2/eV-1) $1.49{\times}10^{12}$ (Cm-2/eV-1) $1.23{\times}10^{12}$ (Cm-2/eV-1)이다. 측정결과 Dit는 Icp가 높은 지점에서 추출되며 온도가 높아지게 되면 Icp전류가 낮아지고 Dit가 줄어드는 것을 볼 수 있다. 온도가 올라가게 되면 carrier들이 trap 준위에서 conduction band 위쪽에 이동하게 되어서 interface에 trap되는 양이 작아지게 된다. 그래서 이때 Icp를 이용해 추출한 Dit 는 실제로 trap의 양이 줄어든 것이 아니라 Thermal excess 현상으로 인해 측정되는 Icp의 양이 줄어든 것으로 분석할 수 있다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.99-100
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• 2007

유도결합 플라즈마(ICP)를 이용한 CVD 장치에서 플라즈마를 발생시키기 위한 안테나의 구조는 매우 중요하다. 전자 온도와 전자 밀도에 직접적인 영향을 주게 되며, 뿐만 아니라 증착 물질의 두께 균일도에 결정적인 역할을 하게 된다. 본 연구에서는 플라즈마 특성 균일도 최적화를 위하여 2turn 직렬, 병렬, 혼합의 ICP 안테나의 구조에 대하여 플라즈마 특성 및 $SiO_2$ CVD 증착 특성을 계산하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.97-98
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• 2007

$SiH_4-Ar-O_2$ ICP-CVD에서 증착된 $SiO_2$막의 두께 균일도를 개선시키기 위해 반응가스 주입구의 위치가 두께 균일도에 영향을 주었을 것으로 예상하고, CFD-ACE를 이용하여 2차원 모델링을 하여 최적데이타를 도출하였다.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.1
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• pp.31-36
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• 2009

The exposure of human beings to toxic trace metals (Cu, Zn) continues to be an important public health issue and concern. This study was conducted to assess the exposure to trace metals (Cu, Zn) in the general Korean population by inductively coupled plasma mass spectrometry (ICP-MS) and Atomic absorption spectrometry (AAS). Serum samples were obtained from 40 healthy volunteers. Specimens were collected in special container and we applied sample processing to minimize contamination. We used ICP-MS and AAS to analyze simultaneously the concentration of metals including copper, zinc. Distribution of trace metal levels in the general healthy population showed lower values. The results in this study can provide background data for clinical studies associated with trace metal exposure in the korean population.

• Proceedings of the Korean Vacuum Society Conference
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• 2002.02a
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• pp.129-129
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• 2002

• Applied Science and Convergence Technology
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• v.26 no.6
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• pp.189-194
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• 2017

Effects of gas injection scheme and rf driving current configuration in a dual turn inductively coupled plasma (ICP) system were analyzed by 3D numerical simulation using CFD-ACE+. Injected gases from a tunable gas nozzle system (TGN) having 12 horizontal and 12 vertical nozzles showed different paths to the pumping surface. The maximum velocity from the nozzle reached Mach 2.2 with 2.2 Pa of Ar. More than half of the injected gases from the right side of the TGN were found to go to the pump without touching the wafer surface by massless particle tracing method. Gases from the vertical nozzle with 45 degree slanted angle soared up to the hottest region beneath the ceramic lid between the inner and the outer rf turn of the antenna. Under reversed driving current configuration, the highest rf power absorption region were separated into the two inner islands and the four peaked donut region.

• Proceedings of the Korean Vacuum Society Conference
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• 2002.02a
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• pp.97-97
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• 2002

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.87-91
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• 2021

Various Cu ions are discharged into water from various industries, which results in a severe trouble for groundwater, soil, air, and eventually animals and humans. In this work, graphene oxide (GO) is introduced as a Cu removal absorber and the real-time monitoring method is demonstrated. The results show that GO is a very effective material to absorb Cu ions in the solution. In addition, the residual Cu ions in the solution is monitored via optical transmittance method, which well match with Inductively Coupled Plasma Mass Spectrometer (ICP-MS) analysis.

• Journal of Environmental Health Sciences
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• v.41 no.1
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• pp.30-39
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• 2015

Objectives: This study was conducted to determine the heavy metal contents in commercial herbal medicines in Korea. Methods: Monitoring of lead, arsenic, cadmium and mercury was carried out on 116 samples of eleven types of herbal medicines. Among the total samples, 71 samples were domestic and 45 were imported. The samples were digested using the microwave method. The heavy metal contents were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES) and a mercury analyzer. ICP-AES was used to analyze lead, arsenic cadmium. Mercury was analyzed by the amalgamation method. Results: The mean values of the heavy metal contents in the herbal medicines were Pb 0.64mg/kg, As 0.26mg/kg, Cd 0.07mg/kg and Hg 0.004mg/kg. Of the total samples, one violated the MFDS (Ministry of Food and Drug Safety) regulatory guidance on heavy metals in herbal medicines. Lead was detected at more than 5mg/kg in one sample. The measured values of arsenic, cadmium and mercury in the herbal medicines showed levels lower than the recommended levels for herbal medicines in MFDS regulatory guidance. In the comparison of domestic samples with imported herbal medicines, it was found that one domestic sample surpassed the maximum residue limits for lead. Conclusion: These results will be used to establish the regulation and control of heavy metal contents in herbal medicines. In addition, continuous monitoring is needed to ensure confidence in and the safety of these herbal medicines.