• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.1
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• pp.19-23
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• 2000

Partial discharges(PD)in air insulated electric power apparatus often lead to deterioration of solid insulation by electron bombardments and electrochemical reaction. The PD caused to reduce the life time of power apparatus and to increase power losses. Thus understanding and classification of PD patterns in air are very important to discern sources of PD. In this paper, PD in air by using statistical methods was investigated. We classified air discharges, corona, surface discharges and cavity discharges by Kohonen network. For classification of PD patterns, we used statistical operators and parameters such as skewness$(S^+,\; S^-),\; kurtosis(K^+, K^-),\; mean phase(AP^+, AP^-)$, cross-correlation factor(CC) and asymmetry derived from the mean pulse-height phase distribution$(H_{avg}(\phi))$, the max pulse-height phase distribution $(H_{qmax}(\phi))$, the pulse count phase distribution $(H_n(\phi))$ and the pulse height vs. Repetition rate $(H_q(n))$.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.25-34
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• 1989

This experiment was performed to study the effect of prostaglandin $E_2$ on tooth movement and root resorption in orthodontically treated cats. Twenty five cats were divided into five groups and closed coil springs delivered 80gm were stretched between upper canine and 3rd premolar. $10{\mu}g$ of $PGE_2$ was injected locally in the submucosal area of the upper right canine, while the left side served as a control and was injected saline 0.1ml. The distance between canine tip and central cusp tip of the 3rd premolar was measured. Scanning electron photomicrographs were made of the coronal half of the distal root surface of canines and cemental craterings were observed and quantified using point-counting volumetry. Data were analyzed by 2-way ANOVA and paired t-test. The results were as follows: 1. The rate of tooth movement of the $PGE_2$ side was increased, particularly at 1 day, compared with the control side. 2. The rate of tooth movement was minimum from 7 days to 10 days. 3. The resorption of root surface of the $PGE_2$ side was decreased from 4 days to 10 days, compared with the control side.

• Molecules and Cells
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• v.23 no.2
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• pp.252-257
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• 2007

Escherichia coli HslVU is an ATP-dependent protease consisting of two heat shock proteins, the HslU ATPase and HslV peptidase. In the reconstituted enzyme, HslU stimulates the proteolytic activity of HslV by one to two orders of magnitude, while HslV increases the rate of ATP hydrolysis by HslU several-fold. Here we show that HslV alone can efficiently degrade certain unfolded proteins, such as unfolded lactalbumin and lysozyme prepared by complete reduction of disulfide bonds, but not their native forms. Furthermore, HslV alone cleaved a lactalbumin fragment sandwiched by two thioredoxin molecules, indicating that it can hydrolyze the internal peptide bonds of lactalbumin. Surprisingly, ATP inhibited the degradation of unfolded proteins by HslV. This inhibitory effect of ATP was markedly diminished by substitution of the Arg86 residue located in the apical pore of HslV with Gly, suggesting that interaction of ATP with the Arg residue blocks access of unfolded proteins to the proteolytic chamber of HslV. These results suggest that uncomplexed HslV is inactive under normal conditions, but may can degrade unfolded proteins when the ATP level is low, as it is during carbon starvation.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.599-599
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• 2012

태양광 발전은 태양광의 입사각과 셀 단면이 이루는각도에 따라 출력특성이 변화된다. 따라서 태양의 위치에 따른 출력특성이 바뀌며 이에 의해 발전가능 시간이 변화된다. 더욱이 건재 일체형(BIPV)의 경우 설치 방향을 조절 할 수 없으므로 입사각에 따른 출력특성이 더욱 중요하다. 이와 따라 결정질 태양전지의 입사각에 따른 광학 특성 변화는 태양전지 표면에 형성되는 Texture의 영향을 받는다. 일반적으로 습식 texturing 방법으로는 화학적인 반응을 이용한 WET 공정, 그리고 건식 texturing 방법으로는 플라즈마를 이용한 reactive ion etching (RIE) 공정이 사용된다. 본 연구에서는 RIE, WET 공정을 사용하여 만든 texturing 구조의 결정질 태양전지를 SEM 장비를 이용하여 표면의 형상을 분석하고, 광 입사각에 따른 양자효율의 특성에 대하여 분석하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.400-400
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• 2011

습식 식각과 RIE (reactive ion etching) 텍스처링 된 다결정 실리콘 태양전지의 라미네이팅 공정 전 후에 양자 효율과 광학적 특성 및 전기적 특성의 변화를 관찰 하였다. 두 식각 방법을 이용해 라미네이팅 공정 전 습식 식각의 표면 텍스처 태양전지에 비해 RIE 표면 텍스처태양전지에서 높은 양자 효율이 관측 되었지만, 라미네이팅 공정 후에 두 셀을 비교해 보면 RIE 텍스처링 된 것의 양자 효율이 더 낮아지는 것을 확인 할 수 있었다. 300~1,100 nm의 파장 범위에서 10 nm의 간격으로 양자효율, 반사율, 투과율, 흡수율 및 변환 효율을 측정하였다. 또한, 공정 전 후의 셀의 dark current를 측정하였다. 위 연구 결과를 통해 라미네이팅 공정에 따른 다결정 실리콘 태양전지의 특성 변화를 분석 하였다.

• Journal of National Security and Military Science
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• s.3
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• pp.197-242
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• 2005

Active catalog is a kind of digital content that enables consumers to test the functions and features of products from their PCs as if they were using it in real life, by simulating the actions and responses of the product. This new type of interactive digital content can be used extensively to make sales personnel training manuals, sales tools, user manuals and user trouble shooting documents. With active catalogs, companies will be able to compare different designs, show actions according to different functions, and evaluate user reaction to new products without having to produce a single physical prototype or mock-up. At the same time, consumers will be able to understand and 'operate' the product and make well-informed purchase decisions. In this paper, we present a visual event-driven modeling tool, PlayMo, for creating active catalogs, analyze the advantages of using PlayMo, describe the event-driven method used by PlayMo and also introduce two enhanced characteristics of the Event Flow Chart with which the events in PlayMo are structured. Interactive digital content by using the PlayMo3D makes easy, simple and effective design for e-learning, e-catalogue, e-marketing/sales, e-prototyping, customer support, etc. Through its application-ready 3D function visualization solution, engineers and designers can rapidly turn a CAD design model into a 3D interactive virtual product, and the effective function prototyping job can be also completed within a minute.

• Quality Improvement in Health Care
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• v.14 no.2
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• pp.67-74
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• 2008

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.298-298
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• 2010

최근 태양전지 연구가 활성화 되면서 다양한 종류의 태양전지가 만들어 지고 있다. 이에 따라 태양전지를 정확하게 분석하고 평가하는 방법에 대한 중요성이 커지고 있다. 태양전지의 성능과 품질을 평가하는 방법은 인공태양광조사장치(Solar Simulator)를 사용하여 태양전지의 전류와 전압특성을 측정하는 방법, 양자효율 측정 장치(Quantum Efficiency Measurement System)를 사용하여 태양광의 파장별로 분광반응도를 측정하는 양자효율측정법 등 다양한 방법이 있다. 그 중 양자효율측정법은 태양광의 다양한 파장에 대하여 태양전지가 파장대역마다 어떠한 반응을 하는지 알 수 있고, 그에 따른 태양전지에 사용된 재료의 특성을 알 수 있게 해준다. 일반적으로 양자효율측정은 태양광 아래에서의 상황과 유사한 환경을 만들기 위해 바이어스광을 사용하고, 분광기로 AC광원을 태양전지에 조사하여 측정한다. 바이어스광의 광량 및 AC광원의 주파수에 의해 양자효율 측정결과는 달라질 수 있는데, 이는 태양전지에 사용된 물질에 따라 다른 경향을 보인다. 본 연구에서는 바이어스광과 AC 광원 주파수를 특정한 광주파수대역(100 Hz ~ 1000 Hz)에서 단결정태양전지와 다결정태양전지에 조사하여 측정하였고, 양자효율 대한 영향과 그 결과에 따른 원인을 분석하였다.

• Childhood Kidney Diseases
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• v.21 no.1
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• pp.21-25
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• 2017

Severe hypercalcemia is rarely encountered in children, even though serum calcium concentrations above 15-16 mg/dL could be life-threatening. We present a patient having severe hypercalcemia and azotemia. A 14-year-old boy with no significant past medical history was referred to our hospital with hypercalcemia and azotemia. Laboratory and imaging studies excluded hyperparathyroidism and solid tumor. Other laboratory findings including a peripheral blood profile were unremarkable. His hypercalcemia was not improved with massive hydration, diuretics, or even hemodialysis, but noticeably reversed with administration of calcitonin. A bone marrow biopsy performed to rule out the possibility of hematological malignancy revealed acute lymphoblastic leukemia. His hypercalcemia and azotemia resolved shortly after initiation of induction chemotherapy. Results in this patient indicate that a hematological malignancy could present with severe hypercalcemia even though blast cells have not appeared in the peripheral blood. Therefore, extensive evaluation to determine the cause of hypercalcemia is necessary. Additionally, appropriate treatment, viz., hydration or administration of calcitonin is important to prevent complications of severe hypercalcemia, including renal failure and nephrocalcinosis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.279-289
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• 2000

Residual stress induced in U-bending and tube-to-tubesheet joint processes of PWR's row-1 heat exchanger tube was measured by X-ray method and Hole-Drilling Method(HDM). Compressive residual stresses(-) at the extrados surface were induced in U-bending, and its maximum value reached -319 MPa in axial direction at the position of $\psi$ = $0^{\circ}$. Tensile residual stresses(+) of $\sigma_{zz}$ = 45 MPa and $\sigma_{\theta\theta}$ = 25 MPa were introduced in the intrados surface at the position of $\psi$ = $0^{\circ}$. Maximum tensile residual stress of 170 MPa was measured at the flank side at the position of $\psi$ = $90^{\circ}$, i.e., at apex region. It was observed that higher stress gradient was generated at the irregular transition regions (ITR). The trend of residual stress induced by U bending process of the tubes was found to be related with the change of ovality. The residual stress induced by the explosive joint method was found to be lower than that by the mechanical roll method. The gradient of residual stress along the expanded tube was highest at the transition region (TR), and the residual stress in circumferential direction was found to be higher than the residual stress in axial direction.