• 한국항공우주학회지
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• 제37권2호
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• pp.187-192
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• 2009

지상국과 교신을 위한 위성체의 트랜스폰더를 개발 시작 단계부터 발사 단계까지 동작상태를 시험하기 위한 장비를 설계하였다. 설계한 시험 장비는 COTS(Commercial Off-The-Shelf) 부품을 사용하여 크기와 개발 기간을 단축하였으며, 위성 발사 후 지상국에서도 사용할 수 있도록 설계하였다. 측정 결과 시험 장비의 상향 링크와 하향 링크의 경로 손실은 각각 47.8 dB와 42.6 dB로 나타났다. 또한 송신단의 선형특성은 -50 dBm 출력에서 60.68 dBc의 IMD3를 가진다.

• 한국식품영양학회지
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• 제25권4호
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• pp.974-979
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• 2012

This research was carried out to find herbal preservatives for Makgeolli, as Makgeolli loses its commercial value due to overproduced acidic materials. When Makgeolli was kept at $25^{\circ}C$ to find the changes in acidity, total microbial cell number, yeast cell number, and bacterial species variety, a sudden increase of acidity as well as the disappearance of yeast cells occurred at day 6, and Makgeolli was changed to complete off-flavor. Acetobacter pasteurianus is the main acidifier in Makgeolli and shows a synergy effect in acid formation when cultured in combination with Lactobacillus casei. Among 12 herbs, the ethanol extract of Sutellaria baicalensis showed antimicrobial activity against A. pasteurianus, whereas the ethanol extract of Coptidis rhizoma showed antimicrobial activity against L. casei. Makgeolli added with Sutellaria baicalensis extracts demonstrated a lower acidity than that with Coptidis rhizoma extracts, which indicates that the inhibition of an acetic acid former is more important than that of a lactic acid former in Makgeolli preservation. Sutellaria baicalensis extracts prolonged the shelf life of Makgeolli by 1~2 weeks at a minimal inhibitory concentration ($0.63mg/m{\ell}$) during storage at $10^{\circ}C$.

• 대한전자공학회논문지SP
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• 제40권6호
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• pp.10-19
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• 2003

현재 상용화된 지문인식 시스템은 지문 입력기를 구동하는데 필요한 함수가 표준화 되어있지 않기 때문에 입력기 사이의 호환이 불가능하다. 본 연구의 목적은 지문인식 시스템이 대중화됨에 따라 앞으로 지문인식 시장에서 수요가 예상되는 다양한 지문 입력기 사이의 지문인식이 가능한 시스템의 개발이다. 본 논문에서는 광학식, 반도체식, 열감지 방식의 지문 입력기를 대상으로 하여 지문인식 시스템을 설계 구현하였으며, 융선 개수 정보의 추출 방법과 융선 개수 정보를 이용한 정합 방법을 제안하였다.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2198-2203
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• 2022

As robotics become more sophisticated, there are a growing number of generic systems being used for routine tasks in nuclear environments to reduce risk to radiation workers. The nuclear sector has called for more commercial-off-the-shelf (COTS) devices and components to be used in preference to nuclear specific hardware, enabling robotic operations to become more affordable, reliable, and abundant. To ensure reliable operation in nuclear environments, particularly in high-gamma facilities, it is important to quantify the tolerance of electronic systems to ionizing radiation. To deliver their full potential to end-users, mobile robots require sophisticated autonomous behaviors and sensing, which requires significant computational power. A popular choice of computing system, used in low-cost mobile robots for nuclear environments, is the UP Core single board computer. This work presents estimates of the total ionizing dose that the UP Core running the Robot Operating System (ROS) can withstand, through gamma irradiation testing using a Co-60 source. The units were found to fail on average after 111.1 ± 5.5 Gy, due to faults in the on-board power management circuitry. Its small size and reasonable radiation tolerance make it a suitable candidate for robots in nuclear environments, with scope to use shielding to enhance operational lifetime.

• Nuclear Engineering and Technology
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• 제45권4호
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• pp.489-504
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• 2013

Software safety for nuclear reactor protection systems (RPSs) is the most important requirement for the obtainment of permission for operation and export from government authorities, which is why it should be managed with well-experienced software development processes. The RPS software is typically modeled with function block diagrams (FBDs) in the design phase, and then mechanically translated into C programs in the implementation phase, which is finally compiled into executable machine codes and loaded on RPS hardware - PLC (Programmable Logic Controller). Whereas C Compilers are fully-verified COTS (Commercial Off-The-Shelf) software, translators from FBDs to C programs are provided by PLC vendors. Long-term experience, experiments and simulations have validated their correctness and function safety. This paper proposes a behavior-preserving translation from FBD design to C implementation for RPS software. It includes two sets of translation algorithms and rules as well as a prototype translator. We used an example of RPS software in a Korean nuclear power plant to demonstrate the correctness and effectiveness of the proposed translation.

• 한국항공우주학회지
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• 제37권4호
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• pp.413-418
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• 2009

소형위성 관제용 S대역 프로토타입 트랜스폰더를 상용 부품을 활용하여 설계하였으며, 확장성까지 고려하여 QPSK 변복조 기능을 FPGA를 사용하여 구현하였다. 제작된 트랜스 폰더는 RF Front End, RF 변조기, RF 복조기, 그리고 변복조기로 구성된다. 측정결과 트랜스폰더의 수신 비트오율(이하 BER)은 -105 dBm의 입력전력에서 $1.1{\times}10^{-6}$으로 나타났다. 이러한 방식의 트랜스폰더는 개발기간을 단축할 수 있으며 크기와 무게를 줄일 수 있는 장점이 있다.

• Journal of Computing Science and Engineering
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• 제11권1호
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• pp.9-23
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• 2017

NuDE 2.0 (Nuclear Development Environment 2.0) is a formal-method-based software development, verification and safety analysis environment for safety-critical digital I&Cs implemented with programmable logic controller (PLC) and field-programmable gate array (FPGA). It simultaneously develops PLC/FPGA software implementations from one requirement/design specification and also helps most of the development, verification, and safety analysis to be performed mechanically and in sequence. The NuDE 2.0 now consists of 25 CASE tools and also includes an in-depth solution for indirect commercial off-the-shelf (COTS) software dedication of new FPGA-based digital I&Cs. We expect that the NuDE 2.0 will be widely used as a means of diversifying software design/implementation and model-based software development methodology.

• 한국산학기술학회논문지
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• 제10권3호
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• pp.579-588
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• 2009

기업과 정부기관은 COTS를 사용한 정보시스템을 개발하고 있다. 특히, COTS는 정보보호시스템과 정보시스템의 컴포넌트로 활용되고 있다. 본 연구는 보안기능 개발을 위해서 필요한 COTS의 선택 수준과 비용을 고려할 때 COTS 컴포넌트의 우선순위를 제시한다. 보안기능 컴포넌트 선택과 관련된 비용 효과적인 의사결정을 위하여, 본 연구는 정보보호기술을 계층화하고, 다기준의사결정 기법을 사용하여 COTS 컴포넌트의 우선순위를 제시한다.

• 한국정밀공학회지
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• 제28권12호
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• pp.1388-1396
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• 2011

This paper is focused on the procedure of the development of a micro air vehicle which has vertical take-off and landing capability for indoor reconnaissance mission. Trade studies on mission feasibility led to the proposal of a coaxial rotorcraft configuration as the platform. The survey to provide a guide for preliminary design were conducted based on commercial off-the-shelf platform, and the rotor performance was estimated by the simple momentum theory. To determine the initial size of the micro air vehicle, the modified conventional fuel balance method was applied to adopt for electric powered vehicle, and the sizing problem was optimized with the sequential quadratic programming method using MATLAB. The designed rotor blades were fabricated with high strength carbon composite material and integrated with the platform. The developed coaxial rotorcraft micro air vehicle shows stable handling quality with manual flight test in indoor situation.

• 우주기술과 응용
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• 제3권3호
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• pp.257-279
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• 2023

한국항공우주연구원에서는 심우주 탐사를 위한 핵심 기술 개발을 위해 6U급 초소형 위성인 HiREV(high resolution video and image)를 개발하였다. 6U HiREV 초소형 위성의 임무는 지구 관측을 위한 고해상도 영상 및 동영상 촬영이며, 임무 수행 시 고온의 카메라 모듈로 인해 렌즈와 모듈 간의 열 지향 오차가 발생할 수 있다. 열 지향 오차는 해상도에 큰 영향을 미치므로, 이를 해결하기 위해 열 설계가 필요하다. 또한 HiREV 광학 카메라는 지상에서 쓰이는 상용제품(COTS, Commercial Off The Shelf)을 이용하여 개발한 것이므로 상온에서 가장 좋은 성능을 가지며, 고온/저온 환경인 우주에서 활용되기 위해 별도의 열 설계가 적용되어야 한다. 본 논문에서는 임무 카메라 탑재체를 위해 3가지의 수동 열 설계가 수행되었으며, 궤도열 해석을 통하여 열 설계가 효과적임을 확인하였다.