• 조명전기설비학회논문지
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• 제27권3호
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• pp.79-86
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• 2013

In order to analyze the electrical performance of ZnO surge arresters stressed by the combined DC and AC voltages that are generated in DC/AC converter systems, the leakage current properties of ZnO surge arrester blocks deteriorated by impulse currents were investigated. The test specimens were deteriorated by the 8/$20{\mu}s$ impulse current of 2.5kA and the leakage currents flowing into the deteriorated zinc oxide(ZnO) arrester blocks subjected to the combined DC and power frequency AC voltages are measured. As a result, the leakage currents flowing through deteriorated ZnO surge arrester blocks were higher than those flowing through the fine ZnO surge arrester blocks and the larger the injection number of 8/$20{\mu}s$ impulse current of 2.5kA is, the greater the leakage current is. The leakage current-voltage curves(I-V curves) of the fine and deteriorated ZnO surge arrester blocks stressed by the combined DC and AC voltages show significant difference in the low conduction region. Also the cross-over phenomenon is observed at the voltage close to the knee of conduction on plots of I-V curves.

• Journal of Magnetics
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• 제5권4호
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• pp.139-142
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• 2000

The interlayer coupling between adjacent ferromagnetic layers was examined for CoFe/Cu/NiFe trilayer systems. A series of films of CoFe (20 nm)/Cu($t_{cu}$)/NiFe (20 nm) trilayers with Cu spacer thickness, $t_{cu}$, in the range of 1~10 m was deposited on Si(100) wafers at room temperature by DC magnetron sputtering. In order to understand the dependence of the magnetic interaction between ferromagnetic $Co_{90}Fe_{10}$ (wt.%) and $Ni_{81}Fe_{19}$ (wt.%) layers separated by a nonmagnetic Cu spacer on the Cu layer thickness, we investigated the derivative ferromagnetic resonance (FMR) spectra. The FMR results were analyzed using the model of Layadi and Art-man for interlayer interaction. The interlayer coupling constant decreases in an oscillatory manner as the Cu spacer thickness increases up to 10 nm and approaches zero above 10 nm. The interlayer coupling constant is positive for all samples. Hence, it seems that the exchange coupling between adjacent CoFe and NiFe layers separated by a Cu layer is ferromagnetic.

• 트랜스-
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• 제1권
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• pp.1-19
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• 2016

예술은 정치적인 분위기 및 사회의 제도에 따라 시대를 반영하며 끊임없이 변화해왔다. 제 2차 세계대전 이후 정치, 경제, 사회에 큰 변화가 일어남에 따라 문화와 예술에서도 20세기 초기의 모더니즘을 거부하는 반역사적 경향이 나타나게 되었다. 이러한 사회적인 변화로 특히 미국의 무용계에서는 모더니즘을 거부하는 실험의식이 강하고 급진적이며, 전위적 예술성향의 포스트 모던댄스가 생겨났다. 작업의 의도나 표현에 있어 새로운 움직임의 표현을 발견하고 즉흥적인 요소와 실험적 시도의 흐름이 주를 이루었다. 이러한 포스트 모더니즘적 안무특성을 탐구하여 오늘날까지 현대무용 안무 형식에서 나타나는 영향을 알아보는데 본 연구의 목적이 있다. 이에 따라 트리샤 브라운의 작품 중 포스트모더니즘 특성이 가장 잘 나타난 작품 을 선택하였다. 작품에 나타난 포스트모더니즘 성향을 살펴보면 미국의 포스트모던 댄스를 이끈 트리샤 브라운은 1960년대를 시작으로 포스트모더니즘의 주도적 역할을 했던 미국의 사회적 흐름을 무용작품에 적극적으로 받아들여 움직임 자체의 표현과 순수한 움직임을 위한 무용을 강조하였다. 미국의 현대무용가들은 신체자체를 중요하게 생각하며 신체표현이 사실적이고 현실적이며 움직임으로 인해 어떠한 감정표현과 개인의 감성이 배제되어 있다. 일상적인 행동을 무용으로 재창조하고 탁월한 공간사용과 실험적인 안무형태를 형성시켜 무용을 가치 있는 예술로서 각인시켰다. 따라서 브라운의 작품분석을 통해 예술의 한계를 벗어나 새로운 방향을 제시하고 오늘날 현대무용의 움직임과 안무형태에 본질적인 무용예술의 방향을 제시해주었다고 볼 수 있다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제20권3호
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• pp.178-185
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• 2017

Purpose: To evaluate the outcomes of a hybrid prophylactic strategy to prevent cytomegalovirus (CMV) disease in pediatric liver transplantation (LT) patients. Methods: CMV DNAemia was regularly monitored by quantitative nucleic acid amplification test (QNAT) and was quantified in all children. CMV infection and disease were defined according to the International Consensus Guidelines. The hybrid strategy against CMV infection consisted of universal 3-week prophylaxis and preemptive treatment of intravenous ganciclovir regardless of the recipient's serostatus. Results: A total of 143 children who underwent living donor LT were managed using the hybrid strategy. The overall incidence of CMV infection by QNAT was 48.3% (n=69/143). The highest CMV DNAemia positivity was observed in 49.2% (n=60/122) of children in the D+/R+ group, followed by 46.7% (n=7/15) in the D+/R- group. CMV disease was noted in 26.1% (n=18/69) patients. Forty-three (62.3%) children had undergone preemptive therapy consisting of intravenous ganciclovir. No symptomatic patients developed tissue-invasive disease, resulting in no CMV-associated mortality. Conclusion: The incidence of CMV infection was high in pediatric LT patients despite the hybrid strategy. However, tissue-invasive disease in pediatric LT did not occur.

• 한국정보전자통신기술학회논문지
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• 제13권6호
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• pp.605-610
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• 2020

소프트웨어 정의 네트워크가 확장성, 유연성, 네트워크상 프로그래밍이 가능한 특징으로 네트워크 관리에서 표준으로 자리잡아 가고 있지만 많은 장점에도 불구하고 하나의 컨트롤러에 대한 사이버 공격이 전체 네트워크를 영향을 주는 문제점을 가지고 있다. 특히, 컨트롤러에 대한 DDoS 공격이 대표적인 사례로서 다양한 공격 탐지 기술에 대한 연구가 진행되고 있다. 본 논문에서는 최초로 84개 DDoS 공격 Feature 데이터셋을 Kaggle에서 획득한 후 Permutation Feature Importance 알고리즘을 이용하여 상위 20의 중요도를 갖는 Feature를 선택하여 딥 러닝 기반의 CNN 모델에서 학습과 검증을 수행하였다. 이를 통해, 최적의 공격 탐지율을 갖는 상위 13개의 DDoS Feature 선택이 DDoS 공격 탐지율 96%을 유지하면서 적정한 공격 탐지 시간, 정확성 등에서 매우 우수한 결과를 제시하였다.

• 대한수의학회지
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• 제43권1호
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• pp.95-102
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• 2003

Because Staphylococcus aureus (S. aureus) has variable number of short sequence repeat region in coagulase gene, it has been used to investigate the relatedness of S. aureus isolates. In this study, we isolated S. aureus strains from 20 dairy farms with bovine mastitis from September 2000 to August 2001. PCR-RFLP analysis of coagulase gene revealed 10 different patterns. Most of the S. aureus isolates showed only one coagulase gene RFLP pattern per farm. However, there were several S. aureus clones spreading between dairy farms. All the farms showed poor management conditions of milking machine and milker, indicating that managements for mastitis control program include use of proper milking matching, premilking sanitation, and segregation in the S. aureus infection herd. Our data suggest that PCR-RFLP analysis of coagulase gene might be applicable for the epidemiological investigations of S. aureus isolated from bovine mastitis cows.

• 한국환경과학회지
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• 제22권11호
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• pp.1373-1381
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• 2013

Mt. Yeonae is at Gijang-gun in Busan and is surrounded by farming lands on three sides. The search for the species composition and dynamics of local communities were studied at Mt. Yeonae of how spatial similarity decays with geographic distance. The index values of Z$\ddot{u}$rich-Montpellier School's phytosociology at the 12 plots was compared to a distribution of similarly using 20 m quadrates at 12 sites. The specific communities were five including Pinus densiflora - Quercus variabilis community. Six species were significant similarity between neighboring sites by using the spatial autocorrelation coefficient, Moran's I. If Mt. Yeonae was destroyed by an artificial action, some spatial correlated species such as P. densiflora and Q. variabilis will be collapsed because of no maintaining the effective population sizes.

• 충청수학회지
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• 제20권4호
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• pp.367-373
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• 2007

For a unital *-subalgebra of the space $\mathcal{L}^a(X)$ of all adjointable maps on a Hilbert $\mathcal{B}$-module X with a $C^*$-algebra $\mathcal{B}$, we study unitary operator (in such algebra)-valued multiplier ${\sigma}$ on a normal, generating subsemigroup S of a group G with its extension to G. A dilation of a projective isometric ${\sigma}$-representation of S is established as a projective unitary ${\rho}$-representation of G for a suitable unitary operator (in some algebra)-valued multiplier ${\rho}$ associated with the multiplier ${\sigma}$ which is explicitly constructed.

• 아동학회지
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• 제20권3호
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• pp.231-244
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• 1999

This study examined the effects of short and long term playing of video gamer on children's visual parallel processing. All of the 64 fourth grade subjects were above average in IQ. They were classified into high and low video game users. Instruments were a visual parallel processing task consisting of imagery integration items, computers, and the arcade video game, Pac-Man. Subjects were pre-tested with a visual parallel processing task. After one week, the experimental group played video games for 15 minutes, but the control group didn't play. Immediately following this, all children were post-tested by the same task used on the pretest. The data was analyzed by ANCOVA and repeated measures ANOVA. The results showed that relaying short-term video games improved visual parallel processing and that long term experience with video games also affected visual parallel processing. there were no differences between high and low users in visual parallel processing after playing short term video games.

• 한국정보처리학회논문지
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• 제7권6호
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• pp.1973-1979
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• 2000

Driving the need for machine vision system is growing consumer demand for quality and defect-free products. Especially it is the most important in tarpaulin's manufacturing process achieves automatically by machine vision instead of by man vision. In this paper pinholes detection is performed by using morphology algorithms. Top hat transform is one of morphology applications. This transform take high performance of defect detection in the case that unexpected changes occur in some non-uniform background. For pinholes defect, automatic visual inspection system has been developed, which was composed by a line-scan camera, illumination, a frame grabber, a motor driver and control units. This system has excellent capacity to defect pinholes to the 0.1 mm by 0.5 mm in size and to work in moving objects by maximum 20 m/min in speed.