• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.7
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• pp.1258-1270
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• 2000

A synthetic aperture radar (SAR) system is able to provide all-weather, day-and-night, high resolution imaging capability in the wide area of interest, and thus is extremely useful in surveillance for both civil and military applications. In this paper, the X-band high-resolution spaceborne SAR system design is described with the key design parameters for the mission and system requirement characterized by the small satellite platform. The SAR imaging mode design technique is presented, and the standard imaging mode design results are analyzed with respect to image quality performance. In line with the system requirement, X-band SAR payload and ground reception/processing subsystems are designed and the key design results are demonstrated with the outstanding performance characteristics. The designed small satellite SAR system shows the wide range of imaging capability, and proves to be an effective surveillance systems in the light weight, high performance and cost-effective points of view.

• Broadcasting and Media Magazine
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• v.18 no.3
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• pp.40-56
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• 2013

본 연구 논문의 목표는 홀로그래픽 디스플레이 성능평가 항목을 구체적으로 정리하며 성능평가 정의를 기반으로 홀로그래픽 디스플레이의 화질평가 방법을 제안한다. 홀로그래픽 디스플레이를 통하여 제공되는 입체 시 인지요인의 만족지표를 설정하고 디스플레이 되는 홀로그래픽 디스플레이의 광학적 요구 사항과 관련된 성능 평가 항목을 정의 한다. 또한 본 논문에서는 위상 광변조기(Phase SLM)를 이용한 실험장치를 구성하여 획득한 홀로그래픽 재생영상을 분석함으로써 홀로그래픽 디스플레이의 영상이 갖추어야 할 평가지표를 나타낸다. 평가 항목과 관련하여 모듈레이션 전이함수(Modulation Transfer Function)를 이용한 해상도(resolution)와 대조비(contrast)에 대한 결과를 분석하였으며 마지막으로 획득된 간섭무늬(Fringe Pattern)의 랜덤 위상 노이즈(Random Phase Noise)에 따른 화질 저하에 대한 정량 분석결과를 나타낸다.

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1323-1337
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• 2020

GEO-KOMPSAT-2A AMI (Advanced Meteorological Imager) radiometric calibration evaluation is an essential element not only for functional and performance verification of the payload but for the quality of the sensor data. AMI instrument consists of six reflective channels and ten thermal infrared ones. One of the key parameters representing radiometric properties of the sensor is a SNR (Signal-to-Noise Ratio) for the reflective channels and a NEdT (Noise Equivalent delta Temperature) for the IR ones respectively. Other important radiometric calibration parameters are a dynamic range and a gain value related with the responsivity of detectors. To verify major radiometric calibration performance of AMI, an offline radiometric evaluation tool was developed separately with a real-time AMI data processing system. Using the evaluation tool, validation activities were carried out during the GEO-KOMPSAT-2A In-Orbit Test period. The results from the evaluation tool were cross checked with those of the HARRIS, which is the AMI payload vendor. AMI radiometric evaluation activities were conducted through three phases for both sides (Side 1 and Side 2) of AMI payload. Results showed that performances of the key radiometric properties were outstanding with respect to the radiometric requirements of the payload. The effectiveness of the evaluation tool was verified as well.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.4
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• pp.139-147
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• 2009

In this paper, optimum design of energy-aware distributed detection is considered for a parallel sensor network system consisting of a fusion center and two passive sonar nodes. AND rule and OR rule are employed as the fusion rules of the sensor network. For the fusion rules, it is shown that a threshold rule of each sensor node has uniformly most powerful properties. Optimum threshold for each sensor is investigated that maximizes the probability of detection under a constraint on energy consumption due to false alarms. It is also investigated through numerical experiments how signal strength, an energy constraint, and the distance between two sensor nodes affect the system detection performances.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.67-80
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• 2008

Recently, automated construction machines have been developed for technically solving construction industry problems such as labor, productivity, qualify and the profit decrease. In spite of the importance of performance analysis in order to commercialize the automated construction machines, previous studies are mainly forced on developing hardware and software of automated construction machines. The primary objective of this research is to propose the performance analysis model of automated construction machines, which can measure productivity, quality and safety improvement rate based on the research and development phases, and to develop a performance analysis system, which enables performance evaluator to easily analyze the performance of the automated construction machines. Finally, it is anticipated that the effective use of the performance analysis model and computerized system would be able to develop the automated construction machines having high performance, and to establish the marketing strategy effectively in order to increase the possibility of commercialization of the developed construction machines.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2751-2757
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• 2015

To obtain the system requirement specification in the beginning of the precision guidance and control system development, the effectiveness and reliability analysis for the system are necessary. The main purpose of this research is to obtain the system requirement specification by carrying out the effectiveness analysis using the modeling and simulation(M&S) scheme. M&S model is constructed using 6-DOF dynamic model, environment model, guidanc -navigation & control model. Assume that the navigation sensor is consist of inertial navigation sensor(INS) and doppler velocity log(DVL), and the speed and direction of current is environment parameter. The effectiveness analysis is carried out using circular error probability(CEP) and variance analyze scheme. Also, the effectiveness analysis is utilized for cost-performance analysis considering the cost of commercial INS and DVL sensor. This paper shows the high-level INS and the low-level DVL configure a high price-performance integrated navigation system.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.384-385
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• 2003

일상 생활에서 악취로 인한 피해를 줄여 쾌적한 생활환경 유지에 대한 관심이 높아짐에 따라 이에 관련된 탈취제품이 많이 상품화되고 있다. 본 연구에서는 탈취 성능에 대하여 객관적으로 평가할 수 있는 시험 분석법을 개발하고, 탈취 성능 평가방법의 정확도를 확립하기 위해 단계별 불확도 평가를 수행하였다. 측정 불확도 요인을 체계적으로 평가하여 주요 불확도 요인을 파악하고 이를 최소화하기 위하여 어떠한 점을 주의하여야 하는 지를 조사하였다. (중략)

• Review of KIISC
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• v.33 no.6
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• pp.45-49
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• 2023

뉴스페이스 시대가 도래하고 양자컴퓨터로 기존 암호체계의 파훼가 수월해진 오늘날 인공위성의 보안모듈은 고성능의 상용 부품을 필요로 한다. 본 연구에서는 PE와 Al의 복합소재를 활용하여 내방사선 능력이 적은 상용 부품을 사용한 인공위성 탑재 보안모듈의 차폐 방안을 제시하였다. 기존의 Al 단일 소재로 제작된 차폐 하우징의 성능과 경제성을 개선하기 위해 PE와 Al의 복합소재를 연구하였다. 이를 위해 OMERE를 통해 저궤도 위성의 임무 환경을 분석하여 PE와 Al 복합소재의 우주방사선 차폐성능과 Al 단일 소재의 우주방사선 차폐성능을 PHITS와 SRIM을 이용하여 비교분석하였다. 연구 결과, PE와 Al의 복합소재를 활용한 차폐 하우징은 가볍고 경제적인 장점을 가지며, 성능도 크게 향상됨을 확인하였다. 이러한 연구 결과는 보안모듈에 한정되지 않고 위성 부품의 차폐에 새로운 가능성을 제시함으로써, 전반적인 우주산업 발전과 위성의 임무 수행 실패율 감소에 기여할 수 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.666-674
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• 2010

There is a few problems in the preliminary seismic performance evaluation procedure of subway infrastructures, such as cut-and-cover tunnel structures and bridge structures, recently because the characteristics of subway infrastructures are not properly considered in the procedure. In particular, the evaluation procedure of vehicular bridge structures is applied to subway bridges without any modification. Moreover, the present evaluation procedure is lack of both theoretical and empirical backgrounds, which makes the evaluation less reliable. This paper presents problems in the existing preliminary evaluation procedure and proposes possible modification(revision) to the procedure.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2001.11a
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• pp.29-32
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• 2001

본 논문에서는 현재 대두되고 있는 IT 보안정책중 위험관리의 한 분야인 위험분석 과정을 살펴보았다. 그 중에서도 위험분석의 핵심 역할을 수행하는 취약점 분석 과정에 대해서 연구하였다. 먼저 보안관리와 위험관리의 일반적인 개념을 설명하였고, 다음은 취약점 분석의 중요성을 설명하면서 효율적인 취약점 분석을 위해 단계별 분석과정을 도식화하였다. 그리고 각 분석 단계마다 간략한 모듈을 만들어 단순하면서도 체계적인 분석 방법을 제시하였다