• 조명전기설비학회논문지
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• 제23권5호
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• pp.110-119
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• 2009

본 연구에서는 임의의 각도로 분기되어 있는 전력선로 근방의 자계를 유도하여 정식화 하였으며 이 공식을 이용함으로써 그 자계 계산을 쉽게 할 수 있다. 이 공식들은 분기선로가 있는 배전선로의 설계 시 검토자료로서 활용할 수 있을 것으로 생각된다. 예로서 자계요소에 관한 공식들을 분기선로가 있는 3상 배전선로 모델에 적용하여 메틀랩 프로그램에 의해 계산하였으며 그 결과를 제시하였다. 그 분석결과를 요약하면 다음과 같다. 합성자계는 분기각이 작고 관측점의 높이 z가 낮으면 전 y-축상에 걸쳐 By 요소가 지배적이다. 이 합성자계는 분기각 ${\alpha}=\frac{\pi}{2}$[rad]의 경우 Bx의 영향을 크게 받는다. 또한 이 합성자계는 전력선 높이와 같은 전선로 근방에서 Bz요소가 지배적이며 분기각이 ${\alpha}>\frac{\pi}{2}$[rad]의 경우에는 y축의 분기전선 위치에서 매우 큰 값을 나타낸다.

• 대한전자공학회논문지SD
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• 제40권7호
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• pp.532-541
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• 2003

메모리에서의 대부분의 전력은 프리디코더 라인, 워드 라인, 그리고 비트 라인 등과 같은 커패시턴스가 큰 라인들에서 소모된다. 이 라인들에서의 전력 소모를 줄이기 위하여 전하 재활용과 전하 공유를 사용한 세 가지 기법들이 제안되었다. 이 기법들은 전하 재활용 프리디코더(charge recycling predecoder, CRPD), 전하 재활용 워드 라인 디코더(charge recycling word line decoder, CRWD), 그리고 롬을 위한 전하 공유 비트 라인(charge sharing bit line, CSBL)이다. CRPD와 CRWD는 프리디코더 라인과 워드 라인의 전하를 재활용하여 소모 전력을 반으로 줄여주고, 전하 공유 기법을 사용하는 CSBL은 롬 비트라인의 스윙 전압을 낮춤으로써 소모 전력을 크게 줄여준다. CRPD, CRWD, 그리고 CSBL의 소모 전력은 기존의 82%, 72%, 그리고 64%이다. 제안된 세 가지 기법들을 사용하는 전하 재활용 전하 공유 롬(charge recycling and charge sharing ROM, CRCS-ROM)이 0.35㎛ CMOS공정으로 제작되었다. 제작된 8K×16비트 CRCS-ROM의 코어 크기는 0.51㎟이고 3.3V 전원과 100㎒ 동작 주파수에서 8.63㎽ 을 소모하였다.

• 한국약용작물학회지
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• 제26권6호
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• pp.471-476
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• 2018

Background: Astragalus membranaceus belonging to the Leguminosae family is often utilized as a traditional medicine. The aim of this study was to elucidate the basic breeding information required to develop short stem A. membranaceus cultivars. Methods and Results: Roots of A. membranaceus advanced yield trial (AYT) lines were harvested in late October 2017. Root yield of six AYT lines were increased in a range of 8.9 - 74.8% compared with 'Aseong' as control (check variety). The height of seven AYT lines were shorter than that of 'Aseong'. In addition, stem diameter of nine AYT lines was thicker than that of 'Aseong'. Consequently, 1502-56, 1503-90, and 1510-80 were selected as elite lines for the development of short stem cultivars. HPLC analysis was perfromed to identify lines with high level active components such as calycosin-7-O-${\beta}$-D-glucoside and calycosin. The levels of both active components were higher in 1502-56, and 1503-90, but not in 1510-80 compared to 'Aseong'. In addition, 2,2-Diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity was higher in the 1502-56 compared to 'Aseong'. Considering these results, two AYT lines, 1502-56 and 1503-90 were selected as short stem lines with high calycosin-7-O-${\beta}$-D-glucoside and calycosin content. Conclusions: Taken together, Two short stem lines were identified in this study. In our future study, regional yield trial (RYT) will be conducted using these selected lines to develop new cultivars.

• 전기학회논문지
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• 제57권10호
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• pp.1688-1695
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• 2008

Recently, it is common in a distribution system of Korea Electric Power Corporation (KEPCO) to find instances where distribution lines are parallel. A traditional method of an induced voltage calculation is not suitable for parallel distribution lines. For more actual analysis of induced voltage on telecommunication lines in parallel distribution lines, a new calculation method is needed. This paper presents a new calculation method of an induced voltage on telecommunication line using equivalent ${\pi}$ circuits matrix in parallel distribution lines. The advantages of the calculation method are using actual neutral current value and not using screening factor for considering the overhead ground wire and the neutral wire. To verify the effectiveness and the accuracy of the method, various case studies are performed with EMTP(Electro-Magnetic Transients Program).

• Journal of Advanced Marine Engineering and Technology
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• 제35권5호
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• pp.690-699
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• 2011

A numerical model analysis was performed to analyze the stability of the mooring lines of an automatic submersible fish cage system in waves and currents. The fish cage system consisted of a 12-angled rigid frame, net cage, cover net, 12 upper floats, 12 tanks(for fixed and variable ballast), mooring lines, anchors, and a control station. Simulations were performed with the cage at the surface of the water and at a depth of 20 m. A Morison equation type model was used for simulations of the system in two configurations. The force parameters described both regular and random waves, with and without currents, and their values were input to the model. Mooring tension calculations were conducted on the mooring lines, grid lines and lower bridle lines of the cage. The stability of the mooring lines was checked under both static and dynamic conditions.

• 전자공학회논문지C
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• 제34C권10호
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• pp.89-97
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• 1997

Because a map consists of many lines, a process of recognizing an object in a map is one to group lines that are consistent with the structure of the object. Therefore, it is important to establish an efficient method for finding lines which constitute objects. In this paper, a novel method for recognizing roads and districts in a land register map is proposed. In this method, lines that constitute objects are searched in a reduced search space by defining some relations between lines, and objects are recognized by using the structural information of the objects. As a result, the search space is reduced effetively, and even objects that embody the broken lines and the crossed lines are recognized.

• 대한수학교육학회지:학교수학
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• 제4권1호
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• pp.1-13
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• 2002

The purpose of this study is to investigate the reasons and backgrounds of drawing auxiliary lines in the proof of geometry. In most of proofs in geometry, drawing auxiliary lines provide important clues, thus they play a key role in deductive proof. However, many student tend to have difficulties of drawing auxiliary lines because there seems to be no general rule to produce auxiliary lines. To alleviate such difficulties, informal activities need to be encouraged prior to draw auxiliary lines in rigorous deductive proof. Informal activities are considered to be contrasting to deductive proof, but at the same time they are connected to deductive proof because each in formal activity can be mathematically represented. For example, the informal activities such as fliping and superimposing can be mathematically translated into bisecting line and congruence. To elaborate this idea, some examples from the middle school mathematics were chosen to corroborate the relation between informal activities and deductive proof. This attempt could be a stepping stone to the discussion of how to teach auxiliary lines and deductive reasoning.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권4호
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• pp.117-122
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• 2003

The AC power lines and signal lines of info-communication networks are routed on overhead poles and are highly exposed to lightning strikes. Due to the potential difference between grounding points of AC power lines and signal lines, the electronic equipments connected to the signal lines can easily be damaged by lightning surges. In this work, in order to develop reliable methods of protecting information and communication facilities from lightning surges, the reliability and performance of SPDs (surge protective devices) were experimentally investigated in an actual-sized test circuit. The behaviors of SPDs against lightning surges from AC power lines and signal lines and the coordinated effects of SPD installation methods were evaluated. As a consequence, it was confirmed that the bypass arrester methods and common grounding system are both highly effective.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.137-159
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• 1998

For the construction of railroads in Metropolytan area based upon the outcome of the future demand forecast, a total of 21 lines including electrified double track segment of Ui-Jung-Bu↔Dong-Du-Chun(18.9km) in Kyung-Won Line is expected. Considering the financial difficulties and investment effect of the lines, this in the sequel brings about an important matter of deforming priority Investment plan to build electrified lines among the candidates. In the case of Japan, Tokyo metropolytan area covered In total by 2,070.1km of various lines, i.e., subway lines(241km), private lines(952.7km), JR lines(876.4km), provides convenient means of transportation for the coummuters and makes a contribution to the development of its neighboring areas and to the expansion of settlement areas. Comparing the total length per 1,000$\textrm{km}^2$, Tokyo(105), Paris(117), and London(115) are at least 6 times as large as ours(15). The purpose of this study is two fold provide a basic scheme for building railroads in metropolytan area and determine priority order in accordance with some evaluation criteria.

• 전기학회논문지
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• 제59권7호
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• pp.1221-1225
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• 2010

The application of the AC and DC lines on the same transmission tower is an economical and practical approaching that increase the power transmission capacity of an existing transmission corridor. But, In this case, Inductive and capacitive coupling between AC and DC lines on the same tower should be investigated in advance. According to the installation plan of 80kV ${\pm}$60MW bipole HVDC in Cheju, KOREA that will be commissioned until 2011, DC lines will parallely operate with 154kV 2 AC lines in existed 154kV AC 4 lines transmission tower. This paper presents the steady state analysis results about the interaction between 154kV AC and 80kV DC lines in the same transmission tower.