• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2149-2151
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• 1999

This paper describes the impulse response characteristics of the grounding systems in power utility system. Several regulations regarding to electric power equipments, services and managements require that the groundings of class 1 ($E_1$) and class 2 ($E_2$) must be connected at the common point in grounding systems. In addition, the grounding for arrester ($E_{LA}$), which belongs to the grounding of class 1, should be connected at the same point. However, there is no method and position of common-connection at anywhere. In this work, when the impulse current was injected through the grounding conductor for arrester, the investigations measuring and analyzing potential rises induced at the common connection point and other grounding conductors were conducted. The experiments were carried out in the conditions of the grounding conductor of 25m long and the near or remote common connection from ground electrode. The lightning impulse current was applied so as to simulate the on-set of arrester due to lightning and/or switching surges.

• 한국전자파학회논문지
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• 제22권6호
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• pp.605-612
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• 2011

본 논문에서는 차량 앞유리에 탈부착이 가능한 다이폴 형태의 T-DMB 수신용 안테나를 설계하였다. 안테나의 구조는 동박과 급전선의 매우 간단한 구조를 가지며, 운전자의 시야에서 완벽히 벗어날 수 있도록 차량 유리의 테두리 쪽에 존재한다. 차체의 특성과 안테나의 입력 임피던스 특성을 고려하여 제안된 미앤더 형태의 다이폴 안테나는 T-DMB 주파수 대역(174~216 MHz)을 만족한다. Common Mode Stub를 추가한 Flexible 안테나는 차량 앞유리에서 부착되는 위치에 상관없이 안테나의 입력 반사 손실은 -5 dB 이하를 가지는 것이 가장 큰 특징이다.

• 한국자원식물학회지
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• 제25권3호
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• pp.357-362
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• 2012

The potential cultivation of buckwheat species in Luang Prabang region, Lao PDR where the species has not been naturally grown and not traditionally utilized was studied to introduce buckwheat as a new agricultural material, especially for food and medicine. The growth of Tartary buckwheat species was higher than common buckwheat showing 2.3 fold of plant height compared to common buckwheat. Number of flower per plant in Tartary buckwheat (731) was three fold higher than common buckwheat (244). Dry weight per plant was respectively 1.7 g in Suwon No. 1, 2.6 g in Suwon No. 2, and 1.4 g in KW45. The rate average of seed setting was similar between common buckwheat (41 to 46 %) and Tartary buckwheat (44%). Total seed yield of Tartary buckwheat (184 kg/10 a) in 10a could be estimated to be higher than that of common buckwheat (108 kg/10 a).

• Nuclear Engineering and Technology
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• 제15권4호
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• pp.229-235
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• 1983

원자력발전소에서 Common Mode Failures (CMFs)가 상당한 관심을 모으고 있다. 이 논문에서는 중복 시스템의 비가용도(Unavailability)에 있어서의 전체 CMFs를 잠재적 CMFs(Potential CMFs)와 의존성 인간 실수에 의한 CMFs (CMFs of dependent human error)로 나누어 이론적으로 고찰하였다. 결론적으로, 인간 실수의 의존성이 높아질수록 전체 CMFs는 의존성 인간실수에 의해서 주로 영향을 받는다고 할 수 있다. 역으로, 인간 실수의 의존성이 낮아질수록, 전체 시스템의 비가용도는 기계적 고장이나 의존성 인간실수보다 잠재적 CMFs에 의해 지배된다고 할 수 있다. 그리고, 중복 시스템의 비가용도에 있어서 전체 CMFs가 기계적 고장보다 주된 요소임도 알 수 있었다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권9호
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• pp.509-514
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• 2002

The aim of this research is to find out how the common earth network affects the level of the traction return current in the $2{\times}25 kV$ Power Supply System. The traction return current plays a significant role in the operation of the facilities near the rails. It is shown that the common earth network in the $2{\times}25 kV$ power supply system not only minimizes the level of the traction return current, but also increases the safety of the working crew on the railways. In order to determine the relationship between common earth network and the traction return current, we investigated the earth system of the Gyongbu High Speed Line that is constructed following the SNCF regulations. We carried out the field test in the Osong station. The results of the test show that the common earth network minimizes the effect of the traction return current. We also find that the simulated results are very similar to the test results. We concluded that the results of the test can be applied for the rest of the Gyongbu High Speed Line under construction.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.1023-1033
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• 2014

In this paper, performance improved hole-filling algorithm which includes the boundary noise removing pre-process that can be used for an arbitrary virtual view synthesis has been proposed. Boundary noise occurs due to the boundary mismatch between depth and texture images during the 3D warping process and it usually causes unusual defects in a generated virtual view. Common-hole is impossible to recover by using only a given original view as a reference and most of the conventional algorithms generate unnatural views that include constrained parts of the texture. To remove the boundary noise, we first find occlusion regions and expand these regions to the common-hole region in the synthesized view. Then, we fill the common-hole using the spiral weighted average algorithm and the gradient searching algorithm. The spiral weighted average algorithm keeps the boundary of each object well by using depth information and the gradient searching algorithm preserves the details. We tried to combine strong points of both the spiral weighted average algorithm and the gradient searching algorithm. We also tried to reduce the flickering defect that exists around the filled common-hole region by using a probability mask. The experimental results show that the proposed algorithm performs much better than the conventional algorithms.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1515-1517
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• 2005

In this paper, we represent both occurrence reason of Surge-voltage and Leakage-current of AC drive system which is operated by Voltage-type PWM Inverter. It generates a compensating voltage which has the same amplitude as, but the opposite phase to, the common-mode voltage produced by the PWM inverter. The compensating voltage is superimposed on the inverter output by a common-mode transformer. As a result, the common-mode voltage applied to the load is canceled completely. The design method of the active common-mode noise canceler is also presented in detail. Therefore, we try to describe the method controling both of them and all of the proprieties are proved by our experiment.

• Journal of Chest Surgery
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• 제5권2호
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• pp.113-124
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• 1972

Clinical observations were performed on 150 cases of chest trauma, those were admitted and treated at the Department of Surgery, Korea University Woosok Hospital, during the past 8 years period from August 1965 to August 1972. 1. The ratio of male to female patient of chest trauma was 3.4:1 in male predominence and age from 20 to 50 occupied 62% of the total cases. 2. The most common cause of chest trauma was traffic accident in this series. Eighty-one cases[54%] were injured by traffic accident and total cases due to blunt trauma [non-penetrating injury] were 113 cases[75.4%]including the cases with traffic accident, and remaining 37 cases[24.6%] were due to penetrating injury including 25[16.6%] cases of stab wounds. 3. Hemopneumothorax were observed in 645/[96 cases] of the total cases, and etiologic distribution revealed 78.1% due to non-penetrating trauma and 20.8% due to penetrating injury. 4. Rib fracture was found in 50% of cases. Common injuries associated with rib fracture were lung, brain and liver. 5. Most common symptom was chest pain and respiratory difficulty, and common sign associated with chest injury was decreased respiratory sound and subcutaneous emphysema. 6. Conservative non-operative treatment was performed in 94 cases[62.6%] and 56 cases [37.4%] were treated with operative treatment including 31 cases[20.6%] with open thoracotomy. 7. Overall mortality was 9.3%[14 cases] and most common causes of death were due to brain edema,asphyxia and shock.

• 한국유기농업학회지
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• 제26권4호
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• pp.745-757
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• 2018

We analyzed the nuclear ribosomal internal transcribed spacer (ITS) sequence of common buckwheat, Fagopyrum esculentum and tartary buckwheat, F. tataricum. The diversity of the nucleotides and haplotypes, Tajima's D, and Fu's Fs was analyzed and compared among the varieties of common buckwheat and tartary buckwheat. The diversity of nucleotides and haplotypes indicated that the buckwheat populations had undergone rapid population expansion but D and Fs did not support their expansion statistically. The phylogenetic analysis of ITS sequences did not clearly establish the phylogenetic relationships between the varieties of common buckwheat. The In/Del sequence of ITS-1 region could, therefore, be used as a DNA marker to distinguish raw or manufactured products derived from common buckwheat and tartary buckwheat.

• 한국항공우주학회지
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• 제49권3호
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• pp.167-174
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• 2021

NASA Common Research Model의 29.7% 축소 모형에 대하여 저속 풍동시험 조건으로 수치해석을 수행하였다. 낮은 레이놀즈수 영역인 0.3×106에서 Belly sting 모형 지지부를 장착한 CRM의 공력계수를 측정하는 시험이 수행되었으며, 수치해석 결과와 비교하였다. 해석의 타당성을 검증하기 위해 선행연구 조건으로 전산해석을 수행하여 비교하였다. Belly sting 모형 지지부 유무에 대한 해석 결과 지지부에 의한 간섭 효과로 동체뿐만 아니라 주날개, 꼬리날개까지 공력에 영향이 있음을 확인하였다.