• 대한전기학회논문지
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• 제41권5호
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• pp.459-467
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• 1992

This paper presents a new algorithm for the countermeasure to alleviate the line overloads due to contingency without shedding loads in a power system. This method for relieving the line overloads by line switching is based on obtaining the kine outage distribution factors-the linear sensitivity factors, which give the amount of change in the power flow of each line due to the removal of a line in a power system. There factors are made up of the elements of sparse bus reactance matrix and brach reactances. In this paper a fast algorithm and program is presented for obtaining only the required bus reactance elements which corresponds to a non-zero elements of bus admittance matrix, and elements of columns which correspond to two terminal buses of the overloaded(monitored) line. The proposed algorithm has been validated in tests on a 6-bus and the 30-bus test system.

• 한국전기전자재료학회논문지
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• 제15권1호
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• pp.85-92
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• 2002

In this study, we analyzed and experimented micro-strip line inductors and capacitors for a SAW duplexer, an important devise for mobile communication. For SAW duplexers, micro-strip line lumped elements must have small impedance values, below several tens of nH or several tens of pF, and a small area pattern. In this study, we performed theoretical analysis of flat line type, meander line type, and spiral line type inductors and interdigital capacitors on a LiTaO$_3$ Piezo-crystal. We proposed a measurement method to evaluate small values of lumped elements accurately with network analyzer. In experiments, we confirmed validity of the theoretical analysis method through fabrication and characterization of micro-strip line lumped elements. The analysis method in this paper can be applied to SAW duplexers well as other microwave devices.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2002년도 제7차 학술대회 초록집
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• pp.76-76
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• 2002

Purpose： The purpose of this study is to optimize the configuration of body RF coil composed of 4 planar subcoils for low field open MRI. Method： Our low field RE coil is composed of 4 subcoils assumed to be located at both the bottom and top sides of permanent magnet. Each subcoils has 3 main strips. The coil system has mirror inversion symmetry. First, the currents on the strips are obtained by inductance calculation and circuit analysis, Second, all the strips are divided into line strip elements across the strips, the self Inductances of line strip elements and the mutual inductances among the line strip elements are calculated, and current distributions of strip are obtained by circuit analysis, where each strip is considered as parallel combination of line strip elements. Finally all the line strip elements are segmented, magnetic field has been calculated by pseudo electric dipole radiation method, where the current elements are regarded as pseudo electric dipole radiation sources. We have performed above procedures for various configurations of RE coil. The field homogeneity is calculated in the 25 cm DSV.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.432-436
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• 1991

This paper presents a new algorithm for the countermeasure to alleviate without shedding system loads the line overloads due to contingency in power system. This method for relieving by line switching is based on obtaining the line outage distribution factors - the linear sensitivity factors, which give the amount of change in the power flow of each line due to the removal of same other line in the power system. These factors are made up of the elements of Bus Reactance Matrix and branch reactances. In this paper a fast algorithm and program is presented for obtaining only the required Bus Reactance elements which corresponds to a non - zero elements of Bus Admittance Matrix and elements of columns which correspond to two terminal Buses of the overloaded(monitored) line. The proposed algorithm has been validated in tests on the 6 busbar test system

• 한국수학교육학회지시리즈D:수학교육연구
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• 제21권1호
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• pp.1-13
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• 2018

While the utility of the number line is considerable, articulating its conceptual foundation is often neglected in school mathematics. We suggest that it is important to build up strong conceptual foundations in the earlier grades so that number lines can be used in a more meaningful way and that any misconceptions associated with the number line can be prevented or intervened. This paper addresses unit, direction, and origin as the key elements of number lines and presents activities from Davydov's curriculum for early grades that promote exploration of those key elements and may resolve some students' misconceptions. As shown in sample activities from Davydov's curriculum, this paper suggests that students can broaden their perspectives on the number line and use it versatilely in various areas of mathematics learning when they deeply engage in the construction of a number line and have flexibility in interpreting the relationships between key number line elements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.2212-2213
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• 2008

In this paper, we studied the method for simultaneous quenching of a transformer type superconducting fault current limiter (SFCL) with two superconducting elements connected in series. Only an element between two elements of the transformer type SFCL was quenched like the case of the resistive type SFCL. By this quenching characteristics, the power burden of the superconducting element was increased. In order to solve this problem, we connected the neutral line between two superconducting elements and the center of secondary coils. The two elements were all quenched in the transformer type SFCL with a neutral line. As a result, the power burden of superconducting elements was decreased, so it was efficient for the increase of power capacity of the transformer type SFCL.

• Genomics & Informatics
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• 제4권1호
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• pp.11-15
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• 2006

The aim of this study is to identify hRad21-binding sites in human chromosome, the core component of cohesin complex that held sister chromatids together. After chromatin immunoprecipitation with an hRad21 antibody, it was cloned the recovered DNA and sequenced 30 independent clones. Among them, 20 clones (67%) contained repetitive elements including short interspersed transposable elements (SINE or Alu elements), long terminal repeat (LTR) and long interspersed transposable elements (LINE), fourteen of these twenty (70%) repeats clones had Alu elements, which could be categorized as the old and the young Alu Subfamily, eleven of the fourteen (73%) Alu elements belonged to the old Alu Subfamily, and only three Alu elements were categorized as young Alu subfamily. There is no CpG island within these selected clones. Association of hRad21 with Alu was confirmed by chromatin immunoprecipitation-PCR using conserved Alu primers. The primers were designed in the flanking region of Alu, and the specific Alu element was shown in the selected clone. From these experiments, it was demonstrated that hRad21 could bind to SINE, LTRs, and LINE as well as Alu.

• 소성∙가공
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• 제5권2호
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• pp.165-175
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• 1996

the process of strip twisting is practiced for the manufacture of some commercial parts such as elements for tube type line mixers. A thin metal strip with rectangular cross section is twisted thru an angle greater than 180。. Initial geometry is altered in to a complex one with dimen-sional changes. In practice several tryouts are necessary to obtain required dimensional accu-racies. A simple analysis model is proposed to predict the dimensional changes forming torque and axial force.

• 한국전자파학회논문지
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• 제20권2호
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• pp.115-123
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• 2009

본 논문에서는 단락 개방 calibration(SOC) 방법을 이용하여 결함 접지 면을 갖는 전송 선로(DGS)와 short-circuited comb line section의 기생 소자 값들을 추출하였다. Microstrip 선로들로 구성된 단락, 개방, 분포 정수 소자의 산란 파라미터 행렬들은 전자기 시뮬레이터 및 벡터 네트웍 분석기를 이용하여 측정하였다. 제안된 구조의 전자기 영향들은 주파수 독립적인 소자들로 구성된 II형 또는 T형 등가 회로로 각각 표현하였고, 2 포트 네트웍 해석을 수행함으로써, 측정된 산란 파라미터들과 등가회로 소자들 간의 관계를 보였다. 또한, 2차 버터워스 프로토 타입을 갖는 2.4 GHz 대역 통과 필터 설계에 이를 적용하였다. 그 결과, 중심 주파수에서 측정된 $S_{11}$과 $S_{21}$은 각각 -20 dB, -1.3 dB 이고, $0.5{\sim}5\;GHz$에서 예상했던 결과와 5 % 이내의 오차를 보였다.

• 한국시뮬레이션학회논문지
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• 제12권1호
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• pp.21-34
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• 2003

This paper deals with a case study of workload analysis of an operator in an automatic line for machining the race of ball bearing. Eleven machines and three hoppers are installed in the line which is operated by an operator. The elements of operation are separated into machine controlled elements, operator controlled elements and machine/operator controlled elements. In order to analyze the system, time and motion studies are used for gathering input data for the simulation model. The first objective of this study is to evaluate whether the workload of operator is reasonable or not. The second objective is to increase throughput by reducing tact time and the last one is to increase frequencies of inspection by reducing interval. Thus we suggest some ideas for improvement, and as a result, the throughput is improved about 9%. In spite of the increasing of throughput, the allowance of operator is also increased about 4%.