• Journal of IKEEE
• /
• v.23 no.1
• /
• pp.99-106
• /
• 2019

This paper propose a new form of UPQC (Unified Power Quality Compensator) to compensate the current and voltage quality problems of nonlinear loads. The conventional UPQC system consists of a series inverter, a parallel inverter, and a common DC link. A new type of UPQC proposed is a parallel compensator with SVC (Static Var Compensator) added to compensate for the wide compensation range and low DC link voltage. The parallel inverter compensates the reactive power generated by the nonlinear load, and the series inverter compensates the sag and swell generated at the power supply side.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.17 no.4
• /
• pp.663-670
• /
• 2022

This study presents the method for integrating the software assets acquired before the weapon system software reliability test was not formed in the weapon system software development and management manual through JTDLS Batch II case. This paper describes the problems for applying manual's direction to JTDLS Batch II project, and decisions and expected effects.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.46 no.5
• /
• pp.14-28
• /
• 2009

The PageRank algorithm is an important component for ranking Web pages in Google and other search engines. While many improvements for the original PageRank algorithm have been proposed, it is unclear which variations (and their combinations) provide the "best" ranked results. In this paper, we evaluate the ranking quality of the well-known variations of the original PageRank algorithm and their combinations. In order to do this, we first classify the variations into link-based approaches, which exploit the link structure of the Web, and knowledge-based approaches, which exploit the semantics of the Web. We then propose algorithms that combine the ranking algorithms in these two approaches and implement both the variations and their combinations. For our evaluation, we perform extensive experiments using a real data set of one million Web pages. Through the experiments, we find the algorithms that provide the best ranked results from either the variations or their combinations.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.3
• /
• pp.514-522
• /
• 2015

In Microwave Radio Link, it is necessary to consider the radio fading to consistently assure the radio link of the high quality as the distance. If the fixed modulation is used for the microwave radio link, it is difficult to keep the high availability of link for the case of the long distance. Adaptive Modulation(AM) provide good quality on microwave link, but the application of the only-AM is not enough to provide the availability assurance due to the fluctuating characteristics of link capacity. Our previous study has proposed the improvement method of transmission in association with the distance, however the previous method needed to make up for the common application. There was no suggestion of a mathematical formula with a variable. In this paper, we propose an optimized Adaptive Transmission Techniques with calculating formula of the priority traffic transmission capacity based on AM in consideration of the fade margin for the availability assurance as the distance and the comparison of the channel bandwidth for Long-distance Radio Link.

• Proceedings of the Korean Information Science Society Conference
• /
• 2008.06a
• /
• pp.148-149
• /
• 2008

• Proceedings of the Korean Information Science Society Conference
• /
• 2010.06a
• /
• pp.194-195
• /
• 2010

• Proceedings of the Korean Society of Laser Processing Conference
• /
• 1999.05a
• /
• pp.9-13
• /
• 1999

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.6
• /
• pp.147-153
• /
• 2010

When small scale wind and solar power generation systems are connected to conventional power distribution system. It is worried that it can affect the quality of electricity such as voltage variation, power factor, frequency, harmonics and flicker. Therefore, in this research, in order to investigate the effects of wind power generation equipments(AC link method) on electrical power quality, when they are connected to distribution system. Power quality analyzer was installed respectively at the front side of power conversion system of conventional wind generation system and secondary side of consumer's power supply at distribution line. Measurements on power quality were performed and the effects of the wind generation system on distribution system were analyzed when it was and was not operated. The results show that 0.34[%] increase on voltage variation, 0.145 increase on current crest factor and 0.6[$^{\circ}$] deviation on phase difference when the power generation system was operated.

• The Magazine of the IEIE
• /
• v.30 no.8
• /
• pp.64-64
• /
• 2003

국내외적으로, 2.3GHz 대역의 휴대 인터넷 서비스와 이동 고속 무선 패킷 데이터 MBWA(Mobile Broadband Wireless Access) 서비스를 위한 기술 개발 및 표준화 작업이 진행중이며, 이들 기술 표준에서는 데이터 속도의 고속화를 달성하기 위하여 AMC(Adaptive Modulation and Coding)를 요구하고 있다. AMC방식 무선 패킷 시스템은 서비스 지역 내에서 SNR(Signal to Noise Ratio)의 값에 연동하여 가변적인 데이터 서비스 속도를 제공하게 되고, 사용자가 서비스 지역을 이동하면서 제공받는 서비스 품질은 물리 채널의 서비스 속도 변화에 대응하여 변화되므로, 서비스 사업자는 서비스 사용자의 속도 품질을 일정하게 유지하고 관리 제어할 수 있도록 하는 서비스 품질 설계 기준이 필요하다. 따라서, 본 기고문에서는 이들 AMC 방식의 고속 무선 패킷 서비스 시스템 기술의 표준화에 병행하여 공중망 무선 패킷 서비스 시스템의 망 구축 설계시 고려되어야 할 가입자 수용용량과 서비스 품질 등을 산정하고 관리하기 위한 파라미터로서 기지국의 평균 데이터 공급 용량 MDT(Mean Data Throughput), 평균속도 공유 패킷 링크 MSPL (Mean Shared Packet Link) 그리고 서비스 Uniformity 지수 UI(Uniformity Index) 등을 제안하고자 한다.

• The Magazine of the IEIE
• /
• v.30 no.8
• /
• pp.844-852
• /
• 2003

국내외적으로, 2.3GHz 대역의 휴대 인터넷 서비스와 이동 고속 무선 패킷 데이터 MBWA(Mobile Broadband Wireless Access) 서비스를 위한 기술 개발 및 표준화 작업이 진행중이며, 이들 기술 표준에서는 데이터 속도의 고속화를 달성하기 위하여 AMC(Adaptive Modulation and Coding)를 요구하고 있다. AMC방식 무선 패킷 시스템은 서비스 지역 내에서 SNR(Signal to Noise Ratio)의 값에 연동하여 가변적인 데이터 서비스 속도를 제공하게 되고, 사용자가 서비스 지역을 이동하면서 제공받는 서비스 품질은 물리 채널의 서비스 속도 변화에 대응하여 변화되므로, 서비스 사업자는 서비스 사용자의 속도 품질을 일정하게 유지하고 관리 제어할 수 있도록 하는 서비스 품질 설계 기준이 필요하다. 따라서, 본 기고문에서는 이들 AMC 방식의 고속 무선 패킷 서비스 시스템 기술의 표준화에 병행하여 공중망 무선 패킷 서비스 시스템의 망 구축 설계시 고려되어야 할 가입자 수용용량과 서비스 품질 등을 산정하고 관리하기 위한 파라미터로서 기지국의 평균 데이터 공급 용량 MDT(Mean Data Throughput), 평균속도 공유 패킷 링크 MSPL (Mean Shared Packet Link) 그리고 서비스 Uniformity 지수 UI(Uniformity Index) 등을 제안하고자 한다.