• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.225-228
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• 2010

In this paper, the present status of research, development, and required technologies for the thermal barrier type dual-pulse rocket motor of the advanced countries was analysed. The result of the conceptual design of the forward or backward ignition systems was also demonstrated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.5
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• pp.505-518
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• 1987

In this paper, the 2-level and 3-level types of PWM technique have been analyzed, and a multiprocessor has been designed as controller for these two types of PWM inverters. Designed multiprocessor employing a hierarchical structure of a SUPERVISORY PROCESSOR which interconnects three LOCAL PROCESSOR through a common memory technique has showed as elaborate digital control characteristic. Using this multiprocessor configuration the system could gain a great degree of freedom in change of software. Also software was simpler than a single processor configuration.

• Optical Science and Technology
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• v.1 no.2
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• pp.56-64
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• 1997

본 기술해설에서는 초고속 반도체 레이저의 특성을 알아보고 광통신에의 응용을 검토하였다. 먼저 반도체 레이저의 동작 원리를 설명하였고, 초고속 반도체 레이저의 소신호 및 대신호 변조특성에 대해서 기술하였다. 또한, 반도체 레이저를 이용하여 극초단 펄스를 생성하는 방법으로 이득/Q 스위칭법, 외부변조기와 집적화된 반도체 레이저를 이용하는 방법, 모드 록킹법에 대해서 검토하고 펄스 압축법에 관해서도 기술하였다. 초고속 반도체 레이저의 응용으로는 초고속 광통신, 솔리톤 광통신, 전광 시분할 다중/역다중에 관해서 기술하였다.

• Korean Journal of Optics and Photonics
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• v.11 no.2
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• pp.102-107
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• 2000

We propose a new scheme for generating a pedestal-free, femtosecond soliton pulse train by utilizing quasI-adiabatic high order soliton pulse evolution in dispersion decreasing fiber in conjunction with the intermediate pedestal suppression stage. Compression factor over 280 was achieved from lOGHz sinusoidal input, to 176 is soliton pulse train. train.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.425-431
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• 2011

The harmonic distortion level may be significant in electric propulsion systems, as the main loads usually are variable speed propulsion/thruster drives. Distortion of currents and supply voltage waveforms may lead to: Increased power dissipation(losses) in equipment connected to the network, such as generators, motors, transformers, cables, etc., from the harmonic currents, may cause overheating and deterioration of the insulation, and reduced life time of the equipment. In this paper introduced the canceling method of harmonic currents by a multipulse drive with phase shifting transformer. The simulation results indicated a good speed response to the middle speed range of electric propulsion motor. And also, THD(total harmonic distortion) and torque ripple could be reduced in comparing the 12-pulse drive with 6-pulse drive.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.187-190
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• 2009

A multiple pulse rocket motor distributes the thrust energy more effectively compared to typical rocket motor as providing subsequent thrusts by the pulse motors of the missile. The pulse rocket motor is the advanced technology to improve an end game capability of the missile by increasing the range and final velocity. A pulse separation device is the core part of the pulse motor. The pulse separation device of bulkhead type was designed and developed. The elastic-plastic structural analysis of the bulkhead and rupture disc was conducted. Several air tests were also conducted to confirm the structural safety and acceptability about the design concept. Test results were compared with the analysis results, which showed reasonable agreements.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5162-5168
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• 2013

Hopping sequences of Time Hopped Ultra Wideband Impulse Radio (TH-UWB-IR) system are to mitigate multipath fading and to provide the multiple access chances for multi users. For the reliable communications, the same pulses are repeatedly transmitted for a bit duration based on hopping sequences. The proposed decoding scheme utilizes the intervals of inter-codes in a frame where the short interval between two pulses leads to the large interference by the multipath fading. For a single user case, the proposed method obtains 0.5dB gain over the conventional method at BER=$10^{-3}$. Decoding performance of repeated pulses can be increased using the property of the hopping sequences of multi users.

• Proceedings of the KIEE Conference
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• 2005.10a
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• pp.79-81
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• 2005

본 논문은 펄스 삽입 보조 회로를 갖고 있는 12-펄스 브리지 4대를 사용한 36-펄스 back-to-back 전압원 컨버터를 제안한다. 제안된 back-to-back 접압원 컨버터는 교류 연계점에서 유효전력과 무효전력의 독립적인 제어가 가능하다. 펄스 수를 증가하는 원리는 이론적 접근을 사용하여 분석되었다. 제안된 시스템의 동작 타당성은 PSCAD/EMTDC 소프트웨어의 시뮬레이션을 통해 검증되었다. 제안된 back-to-back 전압원 컨버터는 HVDC와 FACTS 장치로 널리 사용될 수 있다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.245-248
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• 2011

A multi pulse rocket motor(MPRM) has several advantages compared to the single one. The range and the terminal velocity of the guided missile can be remarkably increased by the application of the pulse separation device(PSD) to the solid rocket motor which resulted in appropriate thrust distribution. In this study, the full scale heavy type dual pulse rocket motor with the bulkhead type PSD was designed, manufactured, and fire-tested. The bursting time and pressure of PSD were analyzed by the pressure, thrust and vibration results of static fire tests. As a result, the design requirement was verified that bursting pressure is lower than 30% of 2nd pulse operating pressure.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.905_906
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• 2009

본 논문은 한전 전력연구원이 주관하고 명지대학교와 (주)효성이 참여하는 연구과제의 결과물로써 다중펄스 컨버터와 PWM 컨버터로 구성된 20MVA급 Back-to-Back STATCOM의 시스템 구성 및 제어 동작특성에 대하여 정리하였다. 한전 전력연구원과 (주)효성이 국책과제를 통해 순수 국내기술로 개발한 10MVA급 다중펄스 STATCOM의 활용방안으로 10MVA급 PWM STATCOM 1기를 추가하여 두 STATCOM 각각의 DC link단을 연계시킨 20MVA급 Back-to-Back STATCOM을 구성하고 제어 알고리즘을 개발하였다. 또한 PSCAD/EMTDC 소프트웨어를 이용하여 개발한 Back-to-Back STATCOM의 제어 및 동작특성을 분석하였다.