• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11b
• /
• pp.1575-1578
• /
• 2002

본 논문에서는 공간-시간 블록 부호디자인(Space-Time Block Code) 관점에서 직교-디자인(Orthogonal-design) 즉, 최소거리가 5이면서 완전-계수(Full-Rank)인 디자인을 비교대상으로 완전-계수(Full-Rank)가 아니면서 최소거리가 5와7인 두 부호에 관하여 연구되어졌다.

• Proceedings of the KIPE Conference
• /
• 2003.07a
• /
• pp.213-215
• /
• 2003

This paper presents an instantaneous space vector modulated voltage source type three-phase soft-switching PFC rectifier using a single auxiliary resonant DC Link snubber for alternative energy utilizations. in the first place, the operating principle of an active auxiliary resonant DC link snubber circuit is described including its unique features. In the next place, the simulation analysis of three-phase soft-switching PWM rectifier is implemented, and the operating performances or the three-phase voltage-fed PWM rectifier treated here, which can operate under the conditions of sinewave line current shaping and utility power factor are evaluated and discussed on tile basis of this simulation results.

• Bulletin of the Korean Space Science Society
• /
• 2004.10b
• /
• pp.95-95
• /
• 2004

• Bulletin of the Korean Space Science Society
• /
• 2002.05b
• /
• pp.44.1-44
• /
• 2002

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.12
• /
• pp.14-21
• /
• 2013

In satellite operations and space exploration missions, a ranging is one of the most essential technologies to get its navigational information of space probes. Recently, the importance of cross-support between space agencies is increasing for more fine performance of space mission. For cross-support, mutually compatible ranging system between space agencies is recommended. For these reasons, the consultative committee for space data systems (CCSDS) recommends pseudo noise (PN) ranging as a digital standard ranging system. The length of PN sequence in CCSDS standard is proper for deep space missions, however, it is too long to use for ranging in near earth missions. In this paper, we propose Variable Length PN sequence schemes suitable for ranging of near earth satellites, such as low-earth orbit (LEO), medium-earth orbit (MEO) and Geostationary orbit (GEO). Therefore we propose variable length PN sequence ranging system including CCSDS standard for multiple missions.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.542-547
• /
• 2003

A new approach to design of a discrete-time robust $H_{\infty}$ filter in finite horizon case is proposed. It is shown that robust $H_{\infty}$ filtering problem can be cast into the minimization problem of an indefinite quadratic form, which can be solved by implementing the Kalman filter defined in Krein space. The proposed filter is readily derived by simply augmenting the state space model and has the robustness property against the parameter uncertainties of a given system.

• Bulletin of the Korean Space Science Society
• /
• 2004.10b
• /
• pp.223-226
• /
• 2004

This paper presents a feasibility study of an advanced IO board design for the next generation of low-earth orbit satellites. Advanced IO board design includes sensor interface, NO, D/A, Digital Module, Serial Module etc, and allows to process increasing data rates between IO board and CPU board. The higher data rate involved in modem IO board additionally introduce issues such as noise, fault tolerance, command and data handling, limited pin count and power consumption problems. The experience in KOMPSAT-l and 2 program with this kind of problems resulted in using SMCS chip set, a high speed serial link technology based on IEEE-1355 (Space Wire Protocol) (ESA-ESTEC 2003, Parkes 1999), as a standard for next generation of satellite IO board design.

• Bulletin of the Korean Space Science Society
• /
• 1999.09a
• /
• pp.75-75
• /
• 1999

No Abstract, See Full Text

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.11a
• /
• pp.523-525
• /
• 2005

인공위성 탑재컴퓨터의 내부 인터페이스를 위하여 SpaceWire 표준을 적용한 SMCS Chip Set의 사용이 고려되고 있다. SpaceWire는 IEEE-1355 프로토콜을 적용한 것으로 위성체 내에서 다양한 모듈들 간에 손쉬운 표준 인터페이스를 제공한다. 또한 다수의 모듈간의 상호 교차 연결을 위한 Cross-Strap 인터페이스 구현이 간단하게 구현될 수 있으므로 위성 운용 기간 중의 높은 신뢰도를 보장할 수 있다. 본 논문에서는 SpaceWire 표준을 적용한 SMCS Chip Set에 대한 소개와 SMCS Chip Set 통한 데이터 전송에 필요한 소프트웨어 제어절차에 대해서 기술하였다.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.45 no.3
• /
• pp.58-67
• /
• 2008

In this paper, we first point out difficulties faced by CG artists in the shading process: (1) a lot of technical details on shaders required, (2) long rendering time, and (3) repeated trials-and-errors. To make them overcome such difficulties, we propose Shader Space Navigator, a system that efficiently searches for shaders similar to a given query shader from a shader database containing a large number of quality shaders. With Shader Space Navigator, CG artists find appropriate shaders from the database that are very close to the final result shader, and thus complete the shading process easily by slightly tuning some attributes of those shaders. Thus, the CG artists can create their final shaders in an intuitive and efficient way without a large number of time-consuming rendering processes. Also, we deal with implementation issues related to Shader Space Navigator and constructing an abundant shader database in detail.