• Childhood Kidney Diseases
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• v.17 no.2
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• pp.92-100
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• 2013

Purpose: To investigate the clinicopathologic effects of cyclosporine A (CsA) in children with diseases characterized by mesangial immunoglobulin A deposits such as immunoglobulin A nephropathy (IgAN) and Henoch-Sch$\ddot{o}$nlein purpura nephritis (HSPN). Methods: We retrospectively reviewed the clinicopathologic outcomes of 54 children (IgAN, 36; HSPN, 18) treated with CsA. The starting dose of CsA was 5 mg/kg per day, and it was administered in 2 divided doses. The degree of proteinuria and pathologic changes in renal biopsies were evaluated before and after CsA treatment. Results: The mean protein to creatinine ratio decreased from $3.7{\pm}1.5$ to $0.6{\pm}0.4$(P <0.001), and 32 (59.2%) children achieved complete remission of proteinuria after 1-year CsA treatment. Among the 54 children, 24 maintained normal renal function and 25 exhibited microscopic hematuria or proteinuria at the end of CsA treatment. In the HSPN group, 3 children whose initial biopsies indicated class IIIb disease showed class II disease on follow-up, and the follow-up biopsies of 2 children who had class II disease indicated the same class II disease. In the IgAN group, cortical tubular atrophy occurred in 1 child, and no child with IgAN had cortical interstitial fibrosis or tubular atrophy after 1-year CsA treatment. No significant complications were found in the children treated with CsA. Conclusion: Our findings indicate that CsA treatment is effective and beneficial in reducing massive proteinuria and preventing progression to end-stage renal failure in children with glomerular diseases characterized by IgA deposits, such as IgAN and HSPN, within 1 year of treatment.

• Journal of electromagnetic engineering and science
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• v.3 no.2
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• pp.79-85
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• 2003

In this paper, we investigated the degree of compensation for distorted optical pulse of wavelength division multiplexed(WDM) channel with initial frequency chirp generated in optical transmitter. The WDM channel signal distortion is due to chromatic dispersion, self phase modulation(SPM) and cross phase modulation(XPM) in fiber. The considered system is 3 ${\times}$ 40 Gbps intensity modulation direct detection(IM/DD) WDM transmission systems, which adopted mid-span spectral inversion(MSSI) as compensation method. We confirmed that the effect of initial frequency chirp on compensation for signal distortion due to a SPM is gradually decreased as a dispersion coefficient of fiber becomes gradually small. But, in the aspect of a compensation for signal distortion due to both SPM and XPM, the effect of initial frequency chirp on compensation is gradually decreased as a dispersion coefficient of fiber becomes gradually large.

• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.193-196
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• 2003

We have developed a laser welding monitoring system to monitor laser welding process conditions such as sample feed rate, laser focal position, and laser power. A 2 ㎾ Nd:YAG CW laser beam has been applied to the welding of a stainless steel plate (SUS306) to investigate the welding monitoring. Theradiation signal from the weld pool was guided back through the focusing optics and the laser delivery fiber, and measured by a photo detector. By changing the focus of the laser beam along the z-direction, the penetration depth of the welding material has been measured. That shows the penetration depth depends on the frequency fluctuations of the plume signals which can be used in welding quality control.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.844-847
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• 2002

본 논문에서는 단상 thyristor 정류기 구조의 대전력 150KVA급의 mash seam 용접기에 용접 센터링등 여러 가지 용접 효율 향상을 위한 부가 장치를 포함한 용접장치 개발을 통한 용접품질 분석결과를 보이고 있다. 일반적으로 제철소에 사용되는 수10KVA급의 용접기들은 그동안 전량 수입에 의존하던 것을 공동연구를 통해서 국산화에 성공하였다. 본 시스템은 기존의 타사제품의 기능을 포함하여 용접 센터링 장치, 용접 전후단 의 크램핑기능, 선후행 코일의 선단부를 절단하는 shear ing 기능, 용접 휠높이 자동조절기능을 포함하였으며, 자체 설계된 대전력용 변압기, 대전력 절환용 thyristor 제어들을 포함한 용접기로써 기존의 타사제품에 비하여 기능적, 성능적으로 향상된 형태로써 용접 성능 검사에서도 양호한 결과 얻었다. 본 논문에서는 mash seam 용접기의 기본적인 기능설명과 개된 용접기를 기능별로 설명하고, 실용접 결과를 소개하여 향후 계획을 제시한다

• Journal of Educational Research in Mathematics
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• v.8 no.1
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• pp.299-312
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• 1998

In this study, we have investigated the meaning and mechanism of the 'construction' in the operational constructivism and the social constructivism. According to Piaget, a mathematical concept is the operational sch me, which is constructed through the reflective abstraction from a general coordination of activities and operations. The process of the reflective abstraction consists of 'reflechissement'and 'reflexion'. The reflechissement starting from 'intriorisation' concludes with 'thematisation', and the reflexion consists in the 'equilibration' of the result of reflechissement. The 'construction' in the social constructivism includes two process. One is the process from the individual, subjective knowledge of mathematics to the social, objective knowledge of mathematics, and the other is vice versa. The emphases is placed on the 'social interaction' and the 'representation' in this two processes. In this context, if we want to apply the social constructivism, we should clarify the meaning of 'society', and consider the difference between the society of mathematicians and the society of students.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.10
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• pp.1017-1024
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• 2007

This study performed a series of burst tests at ambient temperature using real-scale elbow specimen containing a local wall-thinning defect at it's intrados or extrados and evaluated failure pressure of locally wall-thinned elbows. In the experiment, a 90-degree 100A, Sch. 80 standard elbow was employed, and various wall-thinning geometries, such as length, depth, and circumferential angle, were considered. From the results of experiment, the dependences of failure pressure of wall-thinned elbows on the defect geometries and locations were investigated. In addition, the reliability of existing models was examined by comparing the tests data with the results predicted from existing failure pressure evaluation models for locally wall-thinned elbow.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1411-1420
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• 2003

Comparative maps, representing chromosomal locations of homologous genes in different species, are useful sources of information for identifying candidate disease genes and genes determining complex traits. They facilitate gene mapping and linkage prediction in other species, and provide information on genome organization and evolution. Here, the current gene mapping and comparative mapping status of the major livestock species are presented. Two techniques were widely used in comparative mapping: FISH (Fluorescence In Situ Hybridization) and PCR-based mapping using somatic cell hybrid (SCH) or radiation hybrid (RH) panels. New techniques, using, for example, ESTs (Expressed Sequence Tags) or CASTS (Comparatively Anchored Sequence Tagged Sites), also have been developed as useful tools for analyzing comparative genome organization in livestock species, further enabling accurate transfer of valuable information from one species to another.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.3
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• pp.261-266
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• 2003

이 논문에서는 반능동 진동 흡수기를 통합 시트/섀시 현가 장치에 확대, 적용하여 그 성능을 조사하였다. 통함 현가시스템의 성능분석을 위해 집중 인체질량과 함께 실험적으로 입증된 한 비선형 시트 쿠션 모델을 도입하였다. 또한 3 자유도 시트/섀시 현가시스템의 효과적인 진동제어를 위해 리아푸노브 바이스테이트 제어법칙을 사용하였다. 시뮬레이션결과 반능동 통합 현가장치는 시트 쿠션 모델과 관계없이 운전자의 승차감과 관련 있는 시트의 절대가속도 크기와 시트쿠션의 시트 트랙에 대한 상대변위를 상당히 감소시킬 수 있음을 알 수 있었다. 그러나, 주로 사용되어온 선형 쿠션 모델을 사용한 경우보다 비선형쿠션 모델을 사용한 경우의 제진성능이 약간 저조함을 알 수 있었다. 따라서, 자동차 시트 설계시 성능분석을 위해서는 실제의(비선형의) 시트 쿠션 특성을 적용해야 함을 알 수 있다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1345-1348
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• 2005

We designed the compound CVT (Continuously Variable Transmissions) by combining power circulation mode CVT and power split mode CVT, which have been proposed for connecting 2K-H I differential gear to the V- belt type CVU (Continuously Variable Unit), as an input coupled type. With the designed compound CVT, we carried out theoretical analysis and performance experiments. We proved that the compound CVT had a better performance than either of the power circulation mode or power split mode.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.625-630
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• 1998

Using a modified yeast secretory expression vector, $\alpha$-amylase of Schwanniomyces occidentalis was produced from Saccharomyces cerevisiae. The expression vector contains the a-amylase gene (AMY) harboring its own promoter without the regulatory region and the adenine base at the -3 position from the ATG start codon, its own signal sequence, CYC1 transcription terminator, and SV40 enhancer. The expressed $\alpha$-amylase activity from cells carrying the plasmid was approximately 26 times higher than that from the cells harboring an unmodified plasmid. When Saccharomyces diastaticus was transformed with this modified vector, a 2.5 times higher level of amylolytic activity than that from Sch. occidentalis was observed.