• 전기학회논문지
• /
• 제67권11호
• /
• pp.1542-1548
• /
• 2018

When any faults occurred in electrical railway system, operators need to analysis it quickly and accurately. Existing COMTRADE based analysis tools are not enough to analysis faults occurred in electrical railway system. In this paper, it presents some functions to fault analysis for electrical railway system based on fault data formatted COMTRADE. These functions are implemented in PSCAD/EMTDC and it can be shown that analyzed results against actual electrical fault cases which were occurred in the electrical railway power system.

• 전기학회논문지P
• /
• 제62권3호
• /
• pp.151-158
• /
• 2013

Large generator of power plant is very important. In order to protect large generator from faults, digital protective relay or IED is required. However, all protective relays for generators of the domestic power plant are operated by foreign products. And now, for technological independence from foreign and improvement of import substitution effect, IEDs using domestic technology are being developed. To evaluate performance of developing next-generation power devices, the study of the dynamic characteristics of the power plant, generator system modeling, fault simulation and analysis, should be considered. Specially, To obtain IEEE Standards COMTRADE format for relay operation test, generator system modeling and fault simulation using PSCAD/EMTDC tools must be preceded. Until now, a complete modeling of generator internal windings and fault simulation techniques dose not exist. In this paper, for evaluation performance of relay elements of developing IED, the generator system modeling and various faults simulation using PSCAD/EMTDC tools were performed. And then, the various transient phenomena through obtained relaying signal of developed modeling were analyzed.

• 전기학회논문지P
• /
• 제65권1호
• /
• pp.47-52
• /
• 2016

Fault location identification in the transmission line is an essential part of quick service restoration for maintaining a stable in power system. The application of digital schemes to protection IEDs has led to the development of digital fault locators. Normally, the impedance measurement had been used to for the location detection of transmission line faults. It is well known that the most accurate fault location scheme uses two-ended measurements. This paper deals with the complete design of a fault locator using GPS time-synchronized phasor for transmission line fault detection. The fault location algorithm uses the transmitted relaying signals from the two-ended terminal. The fault locator hardware consists of a Main Processor Unit, Analog Digital Processor Unit, Signal Interface Unit, and Power module. In this paper, sample real-time test cases using COMTRADE format of Omicron apparatus are included. We can see that the implemented fault locator identified all the test faults.

• 국제지역연구
• /
• 제20권4호
• /
• pp.3-22
• /
• 2016

본 논문은 미얀마의 개혁과 개방이후의 무역패턴을 분석하고 동아시아의 한국과 중국 및 일본과의 무역패턴을 분석하였다. 미얀마의 비교우위구조와 국제분업구조를 RCA지수와 TSI지수를 이용하여 분석하였다. 분석기간은 개방 직후인 2012부터 자료 확보가 가능한 최근 2014으로 하였으며, 무역자료는 UN comtrade를 사용하였다. 분석결과 미얀마는 개방이후에 무역의 급격한 성장을 이루고 있을 뿐만 아니라 분업의 구조도 변화되고 있었다. 개방으로 2차산품의 무역비중이 증가하였을 뿐만 아니라 비교우위도 1차산품에서 2차 노동집약산업으로 이동하고 있었다. 한국과 중국 및 일본과의 무역에 있어서도 주로 1차산품과 노동집약재 중심으로 수출이 이루어졌다. 동아시아 3국간의 무역의 구조를 비교하면, 한국은 아직 미얀마와 초기단계의 무역구조를 보이고 있는 것으로 분석되었다. 즉 중국과 일본은 미얀마와 무역 관계가 안정적인데 반해, 한국과 미얀마의 무역은 비교우위 패턴이 안정적이지 않은 것으로 나타났다.

• 자원리싸이클링
• /
• 제30권3호
• /
• pp.63-69
• /
• 2021

폐기물에서의 납 회수 및 재활용을 통해 원료공급 안정화와 환경오염 예방을 동시에 도모할 수 있고 실제로도 최근 폐납축전지 위주의 재활용을 통해 납 원자재 공급 측면에서 긍정적인 효과를 보고 있다. 다만 향후 납 회수 및 재활용의 효과를 극대화하기 위해서 납의 물질 흐름의 현황을 효과적으로 파악할 필요가 있는데, 배출원 등의 복잡성과 다양성으로 인해 관련 조사가 번거로울 수 있다. 이 경우 편의상 인터넷 공개자료를 통한 예비 조사의 선수행이 효과적일 수 있다. 따라서, 본 연구에서는 공공기관 공개자료를 통해 국내 납의 흐름을 파악하여 향후 납 회수/재활용에 효율성을 기여하고자 한다. 이에 본 연구에서는 UN Comtrade와 국내 화학물질배출×이동량 사이트 자료를 이용하여 납의 수입량 및 배출×이동량을 파악하고 이를 국가통합자원관리시스템에서 제시된 납의 흐름과 비교하였다. 그 결과 폐납축전지 등 주요 항목별 관련 납의 흐름이 각 사이트 간에 대략적인 일치를 보였다.

• Fashion, Industry and Education
• /
• 제14권1호
• /
• pp.1-9
• /
• 2016

This study examined the comparative advantage of manmade textile (MMT) industries in the United States (US) and South Korea (SK). The Revealed Comparative Advantage (RCA) framework was used to assess the MMT industries' performance in both countries from 2004 to 2013. With the recent ratification of the United States-South Korea Free Trade Agreement (KORUS FTA), it is important to understand the current state of these industries. Using UN Comtrade export data, the RCA index values were calculated and analyzed for 27 MMT commodities, three aggregate groups, and the whole industry. It was found that SK had a consistent comparative advantage for the whole industry. Furthermore, SK had a larger number of products with a comparative advantage. The research findings indicate that the MMT industry in SK is likely to outperform the US following the complete ratification of the KORUS FTA.

• 통상정보연구
• /
• 제10권1호
• /
• pp.295-314
• /
• 2008

I compared trade structure and competitiveness by sector using industrial classification in UN Comtrade data and SITC. Based on the comparison, I calculated market share, export competitions, RCA, and TSI. and then selected sensitive industries based on competitiveness, and identified the ZOPA and our BATNA. These calculations confirmed the industries damaged by FTA and those benefiting from the FTA between Korea and Japan, the study them developed strategies for VIA negotiation. It is to minimize damages to Korean economy and to maximize benefits from the agreement. The negotiation plan allowed an adjustment period for industries, for which damages are expected, by setting a long grace period before implementing tariffs. Based on the negotiation plan made through economic analysis, I intend. contribute to more efficient promotion of negotiation by extracting the optimal FFA negotiation plan for each manufacturing industry.

• 동아시아경상학회지
• /
• 제7권3호
• /
• pp.49-61
• /
• 2019

Purpose - This study shows that which country has more competitiveness in aerospace industry. The reason why author choose aerospace industry for research is aerospace industry is one of major business in every country in the world instead of infant industry. Research design and methodology - In order to research this topic, there are 3 tools to analyze competitiveness in aerospace industry. To achieve analysis of competitiveness between USA and England, UN comtrade program which provides huge database including time serial data. Results - All of TSI are over zero (0) which means that from 2000 to 2018, USA aerospace industry is export specialization as USA aerospace industry has comparative advantage against England aerospace industry. All of TSI in USA are approaching to figure +1 as export specialization except 2010. Conclusions - Even though RCA value in 2000 is 6.313, however, when time goes by and they are 8.997 in 2005, 8.007 in 2010 and 8.389 in 2015 respectively and RCA value is slightly going down as figure 7 in 2018. we review above market share analysis data, USA has overpoweringly superior competitive power against British aerospace industry.

• The Journal of Asian Finance, Economics and Business
• /
• 제2권4호
• /
• pp.13-20
• /
• 2015

The purpose of this research is to identify the relation between the Korean wave and Korean cosmetics export. Instead of using UN COMTRADE data as with other researches on the similar studies, this paper adopts Google Trends query index with keyword 'Korean drama'as a proxy variable for cultural trade. With controlling export determining factors such as GDPs of import and export countries, distance, R&D, and FTA, this paper examines whether the Korean wave represented by Google Trends contributes to the explosive increase of Korean cosmetics export in the recent years. Moreover, this study also investigates the possible effects of the Korean wave on export that could vary according to the different trade groups by classifying import countries into two groups: 74 countries worldwide and 9 ASEAN member countries. The results reveal that the Korean wave indeed leads to cosmetics export to ASEAN countries but show weak relation with cosmetics export to worldwide.

• 한국산학기술학회논문지
• /
• 제18권7호
• /
• pp.394-399
• /
• 2017

본 국내 교류전철변전소에서는 주변압기 2차측의 위상각이 $90^{\circ}$인 단상 전원을 얻도록 한 스코트 결선 변압기를 설치 운용 하고 있다. 변압기 보호계전기는 내부에서 고장이 발생하는 경우 변압기 전단에서 전력을 차단시키고 변압기 외부 계통의 사고나 일반차량 운행의 경우에는 동작하지 않아야 한다. 정확한 고장의 판단으로 오동작을 줄이는 것이 전력계통을 안정적으로 유지하고 신뢰성을 향상시키는 측면에서 매우 중요하다. 주 변압기 내부 고장 검출장치로는 브흐홀쯔계전기와 비율차동계전기를 설치하여 변압기를 보호하고 있지만 비율차동계전기의 오동작으로 인해 보호기능을 비활성화 시켜놓은 상태로 운용하는 사례가 있다. 본 논문에서는 스코트 변압기의 특성과 비율차동계전기의 특성을 제시하고 보호계전기의 오동작 사례를 분석하였다. 이를 위해 전력계통 해석프로그램을 이용하여 스코트 변압기에 사용되는 비율차동계전기를 모델링하고 A변전소의 Comtrade 파일로 저장된 고장파형을 입력데이터로 사용하여 동작여부를 판단하여 고조파 분석을 수행하였다. 또한, 고장파형 분석을 통해 오동작 사례에 대한 개선 방안을 도출하고자 한다.