• 천문학회보
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• 제44권2호
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• pp.57.2-57.2
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• 2019

BITSE is a balloon mission, which is a solar coronagraph to measure speed and temperature of the solar wind using 4 different wavelength filters and an pixelated polarization camera. KASI and NASA jointly designed, developed, and tested the solar coronagraph. Mainly KASI developed an imaging system and a control system, and NASA developed an optical system and mechanical structures. We mount the BITSE on Wallops Arc-Second Pointer (WASP) of Wallops Flight Facility, and launch it with a 39 mcf balloon of Columbia Scientific Ballon Facility. We will introduce the overall system of the BITSE.

• 한국농촌건축학회논문집
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• 제18권4호
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• pp.17-24
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• 2016

Since the users have direct access to search and browse freely, the open access system has been employed to all the usual modern libraries. However, library space shortage problem created by the continuously increasing printed materials caused the degradation of usability and quality of the library space. Open Access system is superior in user convenience but is inferior in space efficiency. Keeping the open access system is considered as one of the reasons of the space shortage problem. Even though the closed access system does not provide free access or easy browsing for the uses, it's space efficiency is much higher than the open access system. The closed access system should be employed as a plan to relieve space shortage problem. Since the closed access system does not allow the public direct access to books, it is very economical. It also provides much better space efficiency with higher book shelving density. In this article, closed access library system models and their characteristics are examined as the reduction plans for the library space shortage problems.

• 대한임베디드공학회논문지
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• 제13권4호
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• pp.187-194
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• 2018

The operating system for IoT should have a small memory footprint and provide low power state, real-time, multitasking, various network protocols, and security. Although the Zephyr kernel, an operating system for IoT, released by the Linux Foundation in February 2016, has these features but errors generated by the user code can generate fatal problems in the system because the Zephyr kernel adopts a single-space method that both the user code and kernel code execute in the same space. In this research, we propose a space separation method, which separates kernel space and user space, to solve this problem. The space separation that we propose consists of three modifications in Zephyr kernel. The first is the code separation that kernel code and user code execute in each space while using different stacks. The second is the kernel space protection that generates an exception by using the MPU (Memory Protection Unit) when the user code accesses the kernel space. The third is the SVC based system call that executes the system call using the SVC instruction that generates the exception. In this research, we implemented the space separation in Zephyr v1.8.0 and evaluated safety through abnormal execution of the user code. As the result, the kernel was not crashed by the errors generated by the user code and was normally executed.

• 한국조경학회지
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• 제13권2호
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• pp.99-114
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• 1985

^x Open space has become the subject o\ulcorner remarkable, new interest ; and many studies have been done recently. In urban pattern, the significance of open space is not its quantity but how it is arranged. The end of this article is to set up a plan for the open space system for Kyongiu city. This paper has three parts : first, a brief discussion of the concept and function of open space ; secondly, a review of open space system ; and finally, a case study of Kyongju City. Especially, this study is focuced on the methodology in conserving and using prototype plan for historic and cultural environment. The result of this study may be summed up as follows : 1) The open space network for kyongju city can be planned out as a belt and ripple pattern. 2) The linear element of open space must play an important role in connecting each element with the whole open space system. 3 ) The Hwangseong pork can be the focal element of the open space system.

• Journal of Astronomy and Space Sciences
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• 제28권1호
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• pp.93-102
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• 2011

Korea Astronomy and Space Science Institute (KASI) launched the development project of two satellite laser ranging (SLR) systems in early 2008 after the government fund approval of the SLR systems in 2007. One mobile SLR system and one permanent SLR station will be developed with the completion of the project. The main objectives of these systems will be focused on the Space Geodetic researches. A system requirement review was held in the second half of the same year. Through the following system design review meeting and other design reviews, many unsolved technical and engineering issues would be discussed and resolved. However, the design of the mobile SLR system is a corner stone of whole project. The noticeable characteristics of Korea's first SLR system are 1) use of light weight main mirror, 2) design of compact optical assembly, 3) use of KHz laser pulse, 4) use of commercial laser generator, 5) remote operation capability, 6) automatic tracking, 7) state of art operation system, etc. In this paper, the major user requirement and pre-defined specification are presented and discussed.

• 한국항행학회논문지
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• 제25권3호
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• pp.242-247
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• 2021

미국, 중국, 러시아 등 우주 선진국들은 일반적인 지상기반의 우주능력뿐만 아니라 해상기반의 우주능력도 보유하고 있다. 해상기반 우주시스템에는 해상기반 우주감시시스템, 해상기반 우주발사체, 해상기반 우주정보 송·수신 시스템 등이 있으며, 이러한 해상기반의 시스템들은 지상기반의 우주시스템들을 보완해주는 역할을 한다. 따라서 본 논문에서는 주요국가의 해상기반 우주능력을 분석하고, 이를 토대로 우리나라의 해상기반 우주능력의 발전방향을 제안한다. 삼면이 바다인 우리나라의 지리적 특성상 해상기반의 우주시스템은 필수적이며, 우주분야 7대강국으로 발돋움하기 위한 중요한 전략적 요소라고 판단된다.

• Journal of Astronomy and Space Sciences
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• 제30권1호
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• pp.49-58
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• 2013

ARGO-M is a satellite laser ranging (SLR) system developed by the Korea Astronomy and Space Science Institute with the consideration of mobility and daytime and nighttime satellite observation. The ARGO-M optical system consists of 40 cm receiving telescope, 10 cm transmitting telescope, and detecting optics. For the development of ARGO-M optical system, the structural analysis was performed with regard to the optics and optomechanics design and the optical components. To ensure the optical performance, the quality was tested at the level of parts using the laser interferometer and ultra-high-precision measuring instruments. The assembly and alignment of ARGO-M optical system were conducted at an auto-collimation facility. As the transmission and reception are separated in the ARGO-M optical system, the pointing alignment between the transmitting telescope and receiving telescope is critical for precise target pointing. Thus, the alignment using the ground target and the radiant point observation of transmitting laser beam was carried out, and the lines of sight for the two telescopes were aligned within the required pointing precision. This paper describes the design, structural analysis, manufacture and assembly of parts, and entire process related with the alignment for the ARGO-M optical system.

• Journal of Astronomy and Space Sciences
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• 제27권4호
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• pp.345-352
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• 2010

Korea multi-purpose satellite-5 (KOMPSAT-5) is a low earth orbit (LEO) satellite scheduled to be launched in 2010. To satisfy the precision orbit determination (POD) requirement for a high resolution synthetic aperture radar image of KOMPSAT-5, KOMPSAT-5 has atmosphere occultation POD (AOPOD) system which consists of a space-borne dual frequency global positioning system (GPS) receiver and a laser retro reflector array. A space-borne dual frequency GPS receiver on a LEO satellite provides position data for the POD and radio occultation data for scientific applications. This paper describes an overview of AOPOD system and operation concepts of the radio occultation mission in KOMPSAT-5. We showed AOPOD system satisfies the requirements of KOMPSAT-5 in performance and stability.

• Journal of Astronomy and Space Sciences
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• 제35권4호
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• pp.279-286
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• 2018

Radar sensors are used for space situational awareness (SSA) to determine collision risk and detect re-entry of space objects. The capability of SSA radar system includes radar sensitivity such as the detectable radar cross-section as a function of range and tracking capability to indicate tracking time and measurement errors. The time duration of the target staying in a range cell is short; therefore, the signal-to-noise ratio cannot be improved through the pulse integration method used in pulse-Doppler signal processing. In this study, a method of improving the signal-to-noise ratio during range migration is presented. The improved detection performance from signal processing gains realized in this study can be used as a basis for comprehensively designing an SSA radar system.

• 정보처리학회논문지A
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• 제13A권2호
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• pp.95-100
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• 2006

본 논문은 LZSS 압축 알고리즘을 변형하여 임베디드 리눅스 운영체제 파일 시스템으로 사용할 수 있도록 설계한다. 본 논문에서는 PDA 임베디드 리눅스 파일 시스템에 변형된 LZSS 압축 알고리즘을 적용하여 저장 공간의 효율적인 관리를 할수 있도록 하였다. 임베디드 리눅스 기반의 PDA 시스템에 대한 압축 파일 시스템 설계는 메모리 사용을 극대화시킬 수 있다. 이와같이 임베디드 시스템에 압축 파일 시스템을 제공함으로써 임베디드 시스템의 한계였던 소량의 저장 공간 문제를 해결하도록 해준다. 본 논문에서 제안하는 압축 파일 시스템을 사용할 경우 저장 공간을 늘리지 않고 저장 공간을 늘리는 효과를 낼 수 있도록 해준다.