• 한국항행학회논문지
• /
• 제17권2호
• /
• pp.202-207
• /
• 2013

본 논문에서는 병렬 연결된 전송선로를 이용하여 고 비율 비대칭 전력 분배기를 설계하였다. 병렬 연결된 전송선로는 마이크로스트립 기술로 구현하기 어려운 낮은 임피던스의 전송선로를 높은 임피던스 전송선로로 구현하는 방법이다. 비율 비대칭 분배기 구현 시 사용되는 낮은 임피던스를 구현하기 위하여 병렬 연결된 전송선로를 이용함으로서 구현을 쉽게 할 수 있었다. 이러한 설계방법의 타당성을 보이기 위해서 중심 주파수 1 GHz에서 10:1 비율의 비대칭 전력 분배기를 제작하였고, 이것의 특성은 시뮬레이션과 거의 동일함을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 하계학술대회 논문집
• /
• pp.495-498
• /
• 2001

The distribution line through which electricity is supplied from substation to customer generally varies by underground line and overhead line. In contrast that the underground line is shielded, the overhead lines do not have the shield layer. To overcome this weak point of the overhead lines, the aerial bundled cable(ABC) connection systems have been developed. The basic concept of the ABC connection system is the application of the underground cable system containing complete shield layer to the overhead cable system. The ABC system is the innovative technologies which enable the prevention of electric shocks, reduction of the maintenance charge and damage of the cable. This paper give a full detail of vertical connection system applied within a country.

• 한국항행학회논문지
• /
• 제16권5호
• /
• pp.781-786
• /
• 2012

본 논문에서는 캐패시터가 주기적으로 병렬 연결된 전송선로를 이용한 높은 분배 비율을 갖는 비대칭 분배기의 설계와 성능을 제안하였다. 높은 분배 비율을 갖는 분배기에서 요구되는 높은 임피던스 값은 마이크로스트립 선로로 구현 가능한 값으로 제한하였고, 낮은 임피던스 값은 캐패시터가 주기적으로 병렬 연결된 전송선로를 이용하여 설계하였다. 이러한 설계 방법은 선로 임피던스 값이 $10{\Omega}$ 이하의 전송선로를 마이크로 스트립으로 구현 가능하게 하였다. 이러한 설계 방법을 증명하기 위해서 중심주파수 1 GHz이고, 분배 비율이 10:1인 비대칭 분배기를 구현하였으며, 그 결과는 시뮬레이션과 1dB 이내에서 일치함을 보였다.

• 조명전기설비학회논문지
• /
• 제19권1호
• /
• pp.169-174
• /
• 2005

지금까지의 고조파 필터는 중성선 리액터와 지그재그결선의 영상 고조파 전류를 제거하였으나, 부하율에 따라 고조파 저감율이 변하여 경부하에서는 고조파 저감율이 낮아지는 특성이 있고, 중성선 리액터 과열로 중성선 단선 위험의 문제가 발생하였다. 본 Zig-Zag 결선 및 Open Delta 방식을 이용한 새로운 고조파 저감장치(HANOS)는 Zig-Zag 결선의 Core Block내에 추가로 Open Delta 방식을 결선하여 중성선에 연결함으로써 중성선에 흐르는 영상 고조파 전류가 과열 없이 안전하게 제거되는 것을 시험 분석한 결과로 증명하였다.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제51권4호
• /
• pp.471-484
• /
• 2012

It is not easy to find the auxiliary line to solve the problem in connection with the circle, where it is the problem finding the central angle or angle at the circumference in a circle. The purpose of the study is to give an aid for this difficulties. The angle at the circumference is closely related to the arc. And so we looked into the problem in connection with the angle at the circumference in point of view of the arc. We have got the following the results. It is not necessary to draw the auxiliary line when solving the problem in connection with the angle at the circumference in point of view of the arc. And we can find the reason to draw the specific auxiliary in point of view of the arc. We hope that the results of research are given aids to a lot of students.

• Journal of international Conference on Electrical Machines and Systems
• /
• 제2권2호
• /
• pp.246-253
• /
• 2013

The Modular Multilevel Converter (MMC) with full bridge cells is available for utility interactive inverter in high voltage line. When it is interconnected with power line, it is possible to control the active power flow in order to supply or charge the power in the line. This research applied the MMC to grid connection system of distributed generator and a power flow control for the MMC is investigated. Theory of power flow between the MMC and the power line is described and control method of power flow and capacitor voltages on arm cells for the MMC are proposed. And effectiveness of the proposed control method is presented by simulation.

• 조명전기설비학회논문지
• /
• 제26권7호
• /
• pp.92-98
• /
• 2012

It is made compulsory to install SPD for the purpose of protecting electric and electronic devices when an abnormal voltage such as lightning occurs to power line using power frequency of 60Hz. Recently, the high speed communication technology utilizing power line is receiving attention again as a communication technology for smart grid. The SPD influences the performances of power line communication when using SPD and power line communication system together. In order to improve the performance of power line communication, a proposed scheme for series connection of gas discharge tube to ZnO varistor was presented. This paper measured the impacts of series connection of GDT to SPD using ZnO varistor on the limit voltage of Class III SPD. This paper also presented the DC operating voltage of GDT which satisfies the limit voltage of power line communication system and SPD simultaneously.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집
• /
• pp.1936-1942
• /
• 2009

Shinbundang-line is new Metropolitan Railway which was invested by private capital and is under construction for opening in 2010. Now Shinbundang-line pursues various innovation, for example, an express train which uses long distance of each station, and an unmanned operation. And it may be independent of existing metropolitan railway system from a viewpoint of line and fare system. So according to the present plan, Shinbundang-line will be not able to get sufficient demand because of weak connection with existing lines and monotonous function of the line. And it may be difficult to deliver various innovation which Shinbundang-line prepares to passengers. Hereupon, in this paper, I propose 3 methods for increasing competitive power of Shinbundang-line railway. First, making Shinbundang-line a trunk railway line of southern metropolitan area was proposed in relation to northern and southern extension of it. In addition connection with bus and light rail was discussed. Second, multipurpose usage of Shinbundang-line was proposed as express train and conventional passenger train in that line in addition to simple metropolitan railway. Finally, an effective operation method which Shinbundang-line must have was proposed from unmanned driving and fare system side. These methods can improve Shinbundang-line and then it will solve traffic congestion of southern metropolitan area effectively.

• 산업경영시스템학회지
• /
• 제3권3호
• /
• pp.35-39
• /
• 1980

Although the product line produces a large volume of goods in a relatively short time, once the product line is established there are numerous problems that arise in connection with this product line. One of these problems is the problem of balancing operations or stations in terms of equal times and in terms of the times required to meet the desered rate of production. The objective of line balancing is minimizing the idle time on the line for all combinations of work stations subject to certain restrictions. In general, there are two types of line-balancing situations : (1) assembly line balancing and (2) fabrication line balancing. Two approaches to the assembly line balancing problem have been used. The first assumes a filed cycle time and find the optimum number of work stations. The second approach to the assembly line balancing problem assumes the number of work stations to be fixed and systematically coverages on a solution which minimizes the total delay time by minimizing the cycle time. Here the cycle time is determined by the longest station time. In this paper, by using the second approach method, a general mathematical model, problem solutions, and computer program for the assembly line balancing problem is presented. Data used is obtained from the company which has been confronted with many problems arising in connection with their assembly line.

• 한국정보통신학회논문지
• /
• 제23권10호
• /
• pp.1282-1289
• /
• 2019

임피던스 변환회로의 신호 전달특성(S21)을 측정하기 위해서는 두 개의 임피던스 변환회로를 대칭 연결하여야 한다. 하지만 두 개의 임피던스 변환회로를 대칭 연결한 회로의 신호 전달특성은 중간 연결 선로의 길이에 의해 영향을 받는다. 본 논문에서는 임피던스 변화회로의 정확한 신호 전달특성을 얻기 위한 중간 연결 선로의 길이를 수식으로 유도하였다. 수식을 이용하여 계산하면 4:1(50-Ω:12.5-Ω) 임피던스 변환회로의 정확한 신호 전달특성을 얻기 위한 중간 연결 선로의 전기적 길이는 약 45°이다. 계산된 연결 선로의 길이를 적용하여 1GHz에서 λ/4-마이크로스트립 임피던스 변환회로를 제작하여 신호 전달특성을 측정하였다. 제작된 대칭 연결된 임피던스 변환회로의 신호 반사 특성(S11)은 0.980GHz에서 -40.64dB, 신호 전달 특성(S21)은 -0.154dB였다. 이는 제작 회로에 대해 이론적으로 살펴본 중심 주파수의 987MHz 변화, 마이크로스트립 선로의 신호 손실 -0.15dB 값과 거의 동일한 값이다.