• 항공우주기술
• /
• 제10권2호
• /
• pp.20-28
• /
• 2011

저궤도 관측위성의 광학탑재체는 궤도에서 임무수행을 뒷받침하는 위성 본체와 열적으로 분리되어 각각 독립된 열제어를 할 수 있도록 개발된다. 광학탑재체는 내부에 작동하는 동안에 높은 발열량으로 순간적으로 온도가 상승하는 부품 박스인 FPA(Focal Plane Assembly)의 열을 외부로 방출하기 위한 히트파이프, 방열판으로 구성된 냉각 장치(Cooling Unit)를 가지고 있다. 이러한 냉각 장치는 고온 조건에서 내부 발열을 빠르게 외부로 방출할 수 있는 히트파이프의 성능과 충분한 면적의 방열판 면적을 확보하도록 설계되어야 하고, 동시에 저온 조건에서 최저 온도 이상을 유지하는 위한 히터설계도 포함해야 한다. 본 연구에서는 먼저 FPA 냉각 장치의 열제어 요구조건과 현재 열설계 기준의 열해석 결과를 통하여 히터설계에 대한 검토와 설계 제한 조건을 분석을 하였다. 또한 열해석을 이용한 효율적이고 경제적인 위성 히터설계 방식을 제시하고, 이것을 FPA 냉각 장치의 히터설계에 적용하여 개선된 히터설계 요소를 찾았다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.193-194
• /
• 2008

This paper defines the electrical interfaces and limited items to integrate Ka-band communication payload on the satellite system, which includes the detailed interfaces such as bus voltage and data bus according to the related COMS requirements. And the BUS Electrical Interface Simulator introduces to use during the course of validating and accepting between the KA-Band payload and their EGSE. These interface design results are fully validated through the testing with the BEIS and is compliant with the satellite interface control interface requirements.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 B
• /
• pp.1061-1063
• /
• 2002

In this paper, the characteristics of the pyro unit applied to rocket release device in KSR-Ill are analyzed by experimental results, which are the current and voltage waveforms of the battery used as energy source. The precision design approach of the rocket release device can be achieved since the behavior and the required energy of the pyro are identified through the results.

• 디지털융복합연구
• /
• 제12권8호
• /
• pp.243-248
• /
• 2014

IPSec은 네트워크상에서 안전한 통신환경을 제공하기 위해 사용하는 보안 프로토콜로, 헤더 인증(Authentication Header)과 데이터와 송신자를 인증하는 Encapsulating Security Payload (ESP) 서비스를 제공하며, 이에 대한 기본적인 개념과, IPSec의 종류를 알아보고 활용되는 방법에 대해서 조사하였다. IPSec 프로토콜이 악용되었을 때의 문제점과 그에 대한 대응책을 알아보고 IPSec을 통한 DDoS 공격에 대한 해결방법을 제시하여 IPSec 프로토콜 사용을 통한 안전한 통신환경을 구축하고자 한다.

• 전자공학회논문지S
• /
• 제35S권2호
• /
• pp.40-49
• /
• 1998

In this paper, we propose an efficient per-Trunk interworking mechanism between PSTN and ATM network assuming the situation ATM network interworks with PSTN during the evolution period. The proposed mechanism improves the cell payload utilization by mapping only the active charnnels of PSTN frame into ATM cell payload. Also, we propose the frame recovery mechanism to guarantee the frame sequence integrity. The proposed mechanism is compared with other possible ones in terms of cell payload utilization, cell packetization delay. We present the implementation structure of the interworking unit. the correctness of the mechanism and the feasibility of the implementation are verifid through the CAD simulation.

• 한국전산유체공학회지
• /
• 제12권3호
• /
• pp.62-68
• /
• 2007

A conceptual thermal design is performed for the optical payload system of a geostationary satellite. The optical payload considered in this paper is GOCI(Geostationary Ocean Color Imager) of COMS of Korea. The radiative thermal control system is employed in order to expect a small thermal gradient in the telescope structure of GOCl. Two design margins are applied to the dedicated radiator dimensioning, and three kinds of configuration to the heater power sizing. A Monte-Carlo ray tracing method and a network analysis method are utilized to calculate radiative couplings and thermal responses respectively. At the level of conceptual design, sizing thresholds are presented for the radiator and heater on the purpose of determining the mass and power budget of the spacecraft.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.1013_1014
• /
• 2009

In this paper, the electrical interfaces used in between COMS satellite bus and Ka-band communication payload are analyzed to verify the robustness of data bus. The purpose of the serial data bus of satellite is to allow serial data transfer between one bus controller or source equipment to several user terminals or slave equipments. A serial data bus in COMS satellite is mainly used for Channel Amplifier and Digital Control Unit of Ka-band Payload.

• Journal of Astronomy and Space Sciences
• /
• 제16권2호
• /
• pp.131-138
• /
• 1999

We present the results of a model calculation of the stellar distribution in a UV and centered at 2175$\AA$ corresponding to the well-known bump in the interstellar extinction curve. The stellar distribution model used here is based on the Bahcall-Soneira galaxy model (1980). The source code for model calculation was designed by Brosch (1991) and modified to investigate various designing factors for UV satellite payload. The model predicts UV stellar densities in different sky directions, and its results are compared with the TD-1 star counts for a number of sky regions. From this study, we can determine the field of view, size of optics, angular resolution, and number of stars in one orbit. There will provide the basic constrains in designing a satellite payload for UV observations.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1729-1734
• /
• 2005

The use of gantry crane systems for transporting payload is very common in industrial application. However, moving the payload using the crane is not an easy task especially when strict specifications on the swing angle and on the transfer time need to be satisfied. To overcome this problem, this paper describes development of an intelligent gantry crane system based on the mechatronic design. A lab-scale gantry crane is designed and then its intelligent controllers are developed. Fuzzy logic controllers are adopted, designed and implemented for controlling payload position as well as the swing angle of the gantry crane. The performance of the intelligent gantry crane system is evaluated on a hardware-in-the-loop simulation (HILS) environment. Moreover robustness of the proposed system is also evaluated. The result shows that the intelligent gantry crane system designed based on the mechatronic design approach has better performance compared with the automatic gantry crane system controlled by classical PID controllers. Moreover simulation result shows that the intelligent gantry crane system is more robust to parameter variation than the automatic gantry crane system.

• 천문학회보
• /
• 제42권2호
• /
• pp.89.2-89.2
• /
• 2017

Korea Pathfinder Lunar Orbiter (KPLO) is a first Korean Lunar exploration mission. KPLO is equipped with four payloads in Korea and one payload in United States. KMAG is one of Korean payloads to measure the Moon's magnetic field. Moon has a no dipole magnetic field such as earth's global magnetic field. But there are many curious crustal magnetic anomalies. these features still do not well understood. This is a main scientific objective of KMAG payload and the study of space environment around moon is a second objective. KMAG has three magnetometers which are mounted in the edge of the 1.2 meter boom. This paper shows a KMAG's requirements, instrument description, and a preliminary function test results.