• 수산해양기술연구
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• 제40권4호
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• pp.255-267
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• 2004

기선권현망어업의 어구 개량과 조업시스템 개선을 목적으로 자루그물을 A, B 2가지로 달리한 축소형 개량어구를 설계, 제작하여 현장조업선에 의한 해상실험을 실시하여 어구의 형상을 관찰한 결과를 요약하면 다음과 같다. 1. 축소형 개량어구의 실제 전개율은 오비기에서 20% 정도로 가장 작았고, 뒤쪽으로 갈수로 커지며, 자루그물에서는 110% 정도로 가장 컸으며, B형이 A형에 비하여 5~10%정도 크게 나타났다. 자루그물 입구와 뒤끝의 망고 변화폭은 A형이 9.0~13.6, 9.3·10.4m이고, B형이 10.9~14.8, 5.8~8.0m로 나타나서 B형이 A형에 비하여 자루그물 입구는 1~2m 크고, 뒤끝은 2~3m 작았다. 2. 축소형 개량어구는 오비기의 수직방향 전개성능이 개선되어 수비에 이르기까지의 예망수층이 완만하게 형성되었으며, 예망수층의 변화폭이 기존어구에 비해 적게 나타났다. 나발 그물이 포켓형상을 개선시켜 그물코의 날림현상 감소와 수비에서 자루그물까지의 어구형상이 완만하게 이루어졌으며, 예망속도가 느린 경우에도 어구의 형상이 안정되었다. 3. 축소형 개량어구 B형은 자루그물의 변화폭이 적었고, 이중깔대기의 부착으로 인해 입망된 어군의 도피율이 감소하였다.

• Journal of Power Electronics
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• 제11권5호
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• pp.662-668
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• 2011

This paper presents an analysis of a 4th order LCLC resonant converter with a capacitive output filter using the state-space approach. The analysis of the converter shows that there are four intervals in a half period. In each interval, the state-space equations are obtained. Due to the soft switching of the converter, an exact equation for the Zero Voltage Switching (ZVS) time and the maximum dead time of the inverter switches are presented. The simulation and experimental results obtained from a 10kv, 370w prototype confirm the validity of the theoretical analysis.

• 대한수학회논문집
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• 제37권4호
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• pp.1041-1053
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• 2022

In this paper, sharp lower and upper bounds on the third order Hermitian-Toeplitz determinant for the classes of Sakaguchi functions and some of its subclasses related to right-half of lemniscate of Bernoulli, reverse lemniscate of Bernoulli and exponential functions are investigated.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2000년도 추계총회 및 학술발표회
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• pp.7-7
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• 2000

• 한국의류학회지
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• 제36권1호
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• pp.27-35
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• 2012

This study locates typical Korean fashion images in domestic and foreign fashion journals to advance Korea's international image in contemporary global fashion markets. The investigation of the frequency of articles and their types (so as to inquire into interest in Korean fashion in the global fashion markets) showed that for the appearance frequency of domestic articles studied, a good number of articles were published in the first half of 2008 and in 2009. In the case of foreign articles, the number of them increased from the second half of 2008 and the majority of articles were shown in the first half of 2010. Second, the investigation of the appearance features by article type studied in order to understand how Korean fashion played a role in the world's markets. The majority of articles were related to fashion brands that entered Chinese market in fashion brand articles in the case of domestic articles; however, many foreign articles introduced designers that participated in global fashion collections in Paris and New York. Third, as a result of analyzing typical key words by article type in order to find key words which could enhance Korea's fashion national image representing, we could confirm that 'Korean designers' can be a typical key words to represent Korean fashion. The key word most exposed in both domestic and foreign articles was 'designer Lie Sang Bong' and only his articles contained the content about influential Korean design materials.

• 농약과학회지
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• 제18권2호
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• pp.61-68
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• 2014

사과 중 살응애제 etoxazole 및 flufenoxuron의 출하 전 잔류허용기준(PHRL)을 설정하기 위해 각 농약의 생물학적 반감기와 감소상수가 산출되었다. 안전사용기준의 희석배수에 따라 조제된 각 농약을 사과에 대하여 각각 1회 및 3회 살포한 후 사과 중 일자별 잔류량을 조사하였으며, 잔류시험 결과들은 first order kinetics의 지수감소식에 대입되었다. 시험기간 중 두 농약의 잔류량은 모두 잔류허용기준(MRL) 미만으로 나타났으며, 사과 중 생물학적 반감기를 조사한 결과 etoxazole의 경우 1회 처리구에서 8.8일, 3회 처리구에서 21.7일로 나타났다. 반면에 flufenoxuron은 1회 처리구에서 21.7일, 3회 처리구에서 23.1일로 나타나 etoxazole 보다 반감기가 더 길었다. 사과 중 각 농약의 감소상수는 etoxazole은 0.0788, flufenoxuron은 0.0319이었으며, 산출된 감소상수들을 대입하여 PHRL을 계산하였다. 그 결과, 안전사용기준을 준수한 농약살포 시 출하 일주일 전 농약의 잔류량이 etoxazole은 0.87 mg/kg, flufenoxuron은 0.88 mg/kg 이하이면 출하 시 잔류량이 MRL 이하일 것으로 예측되었다.

• 전력전자학회논문지
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• 제4권4호
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• pp.342-348
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• 1999

본 논문에서는 간단한 제어회로와 반브릿지 PWM 인버터로 구성된 저가의 단상능동전력필터에 대해 기술하고 있다. 이 능동전력필터의 성능을 확인하기 위하여 EMTP 프로그램에 의한 시뮬레이션을 실시하고 프로토타입을 제작하여 실험을 실시하였는데, 그 결과 제안하는 능동전력필터는 단상비선형부하가 발생하는 고조파를 제거하는데 우수한 성능을 갖고 있음을 확인할 수 있었다. 제안된 시스템은 반브릿지 인버터와 단일 전류센서를 사용한 간단한 제어회로로 구성되었기 때문에, 하드웨어 비용이 저렴하고 프러그인 타입으로 제작 가능한 장점을 갖는다.

• ETRI Journal
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• 제42권1호
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• pp.17-25
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• 2020

Multiple-input multiple-output systems can achieve a full sum rate (SR) via full duplex (FD). However, its performance is degraded by self-interference (SI) that occurs between the transmitter and receiver at the same node and thus is constrained by error floors. Conversely, half duplex (HD) can avoid the SI albeit at lower spectral efficiency, and the slope of its error curve is determined by the diversity order. In this study, a link selection scheme based on switching between FD and HD is examined as a simple method to improve the bit error rate (BER) performance of FD systems. In the proposed link selection algorithm, either FD or HD is selected based on the received minimum distance and signal-to-interference plus noise ratio. Simulation results indicate that the proposed hybrid FD/HD switching system offers significant BER performance improvement when compared with that of the conventional FD and FD based on only the received minimum distance under the same fixed SR. Under relatively sufficient SI cancellation, it is demonstrated to outperform the HD with a diversity advantage in low and medium signal-to-noise ratio region.

• 한국압력기기공학회 논문집
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• 제14권1호
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• pp.58-65
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• 2018

The purpose of this study is to develop a Half Nozzle Repair(HNR) process to prevent the leakage from welds on small bore piping in Reactor Coolant System. The Codes & Standards of tempered bead and design requirements of J-Groove welds are reviewed. Automatic machine GTAW welding and machining equipments are developed to perform HNR process. Single pass welding and overlay welding equipments are conducted in order to obtain the optimal temper bead welding process parameters with Alloy 52M filler wire. Coarse grain heat affected zone(CGHAZ) is formed by rapid cooling rate in heat affected zone after welding. Accordingly, a proper temper bead technique is required to reduce CGHAZ in 1-Layer of welds by 2- and 3-Layers. Mock-up tests show that the developed HNR process is possible to meet ASME Code & Standard requirements without any defect.

• Computers and Concrete
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• 제4권4호
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• pp.285-298
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• 2007

Corrosion of Reinforcement (rebar) is nondestructively estimated by the half-cell potential measurement. As is the case with other nondestructive testings (NDT), understanding of the underlying principles should be clarified in order to obtain meaningful results. Therefore, the measurement of potentials in concrete is analytically investigated. The effect of internal defects on the potentials measured is clarified numerically by the boundary element method (BEM). Thus, a simplified inversion by BEM is applied to convert the potentials on concrete surface to those on rebars, taking into account the concrete resistivity. Because the potentials measured on concrete surface are so sensitive to moisture content, concrete resistivity and surface condition, an inverse procedure to convert the potentials on concrete surface into those on rebars is developed on the basis of BEM. It is found that ASTM criterion is practically applicable to estimate corrosion from the potential values converted. In experiments, an applicability of the procedure is examined by accelerated corrosion tests of reinforced concrete (RC) slabs. For practical use, the procedure is developed where results of IBEM are visualized by VRML (Virtual Reality modeling Language) in three-dimensional space.