• 대한원격탐사학회지
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• 제39권6_3호
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• pp.1791-1799
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• 2023

한국항공우주연구원은 위성정보활용협의체 소속기관을 대상으로 아리랑위성 시리즈 영상자료 보급 및 활용지원을 담당하고 있다. 협의체 소속기관 사용자들은 대부분 광학 영상 중심으로 위성영상을 활용하고 있으며, 상대적으로 Synthetic Aperture Radar (SAR) 영상에 대한 활용 방안은 미흡한 실정이다. 본 논문에서는 SAR 영상자료 활용을 지원하기 위한 일환으로 향후 개발할 SAR 강도 기반 변화탐지 기술의 결정을 위해 현재까지 연구되어진 SAR 강도 기반 변화탐지 기술과 그 활용사례들을 조사했다. 조사 결과 많은 연구자로부터 강도 차분, 상관계수, 히스토그램(Histogram) 또는 편파 정보를 활용하여 변화 픽셀을 탐지하고 분석하기 위한 다양한 알고리즘들과 도시, 홍수, 산불, 식생과 같은 다양한 분야에서 변화탐지 알고리즘의 활용방안이 연구되었음을 확인할 수 있었다. 본 연구는 위성정보활용협의체에 활용할 SAR 변화탐지 기술 개발에 활용할 예정이다.

• 한국조경학회지
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• 제47권4호
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• pp.68-80
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• 2019

본 연구는 중학교 명상숲의 물리적 환경특성과 이용자들의 이용행태 및 중요도-만족도 등을 분석하여 향후 중학교 명상숲 조성에서 이용자 중심의 설계를 수행하기 위한 기초자료를 제공하는 것에 목적이 있다. 이를 위해 명상숲 대상지의 부지특성, 자연성 기능성, 효과성을 바탕으로 중요도-만족도 분석을 위한 평가지표 24항목을 선정하였다. 광주광역시의 중정형 A, B 중학교 두 곳에서 대상지 현황조사분석과 학생, 교사를 대상으로 설문조사 및 분석을 실시하였다. 연구결과, 첫째 명상숲에 대한 인식과 이용정도는, 두 학교 모두에서 학생의 명상숲 인식정도와 이용률이 교사에 비해 매우 낮게 나타났다. 학교 간 집단비교 결과는 A학교가 B학교에 비해 이용 및 인식정도가 매우 양호하였다. 둘째, 명상숲 이용행태는 휴식(49.6%), 주중 점심시간(63.6%), 친구(65.0%) 또는 동료(60%)와 함께 10분 이하(68.6%)로 이용하는 것으로 나타났다. 꽃이 피는 식물(30.0%)과 녹음수(28.9%)를 좋아하며, 주로 쉼터(57.9%)와 산책로(37.1%)를 이용하였다. 셋째, 중요도, 만족도 분석결과, 전체 24개 항목에 대한 평균은 중요도(3.81)가 만족도(3.62)보다 높았다. I사분면(지속적 유지)의 항목들은 9개, II사분면(우선적 시정)의 항목들은 3개, III사분면(관리운영 시 저우선순위)의 항목들은 7개, IV사분면(과잉노력의 지양)의 항목들은 5개이다. 두 학교 간 만족도에서 통계적으로 유의미한 차이를 보인 16개 항목에 대해서 A학교 만족도가 B학교보다 모두 높게 나타났다. 이는 A학교 명상숲에 규모가 더 큰 숲과 산책로가 확보되어 있고, 접근성이 더 용이하며, 다양한 식재유형 및 식재면적이 제공되고 있어 B학교에 비해 만족도가 더 높은 것으로 판단된다. 넷째, 전반적 만족도 분석결과에서 A학교(68.0%)와 B학교(47.2%) 간 유의한 차이를 보였으며, 이는 A학교의 주요 만족공간인 산책로와 쉼터가 B학교보다 더 잘 조성되어 있어 만족도의 차이가 큰 것으로 판단된다. 전체를 대상으로 한 가장 만족하는 공간의 순위로 산책로(1위), 쉼터(2위)가 선정되었고, 만족하는 이유는 A와 B학교 모두 휴식(스트레스 해소 및 정서함양)이 가장 높게 나타났다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.134-137
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• 2005

Unsupervised spectral angle classification (USAC) is the algorithm that can extract ground object information with the minimum 'Spectral Angle' operation on behalf of 'Spectral Euclidian Distance' in the clustering process. In this study, our algorithm uses the unit vector instead of the spectral distance to compute the mean of cluster in the unsupervised classification. The proposed algorithm (MUSAC) is applied to the Hyperion and ETM+ data and the results are compared with K-Meails and former USAC algorithm (FUSAC). USAC is capable of clearly classifying water and dark forest area and produces more accurate results than K-Means. Atmospheric correction for more accurate results was adapted on the Hyperion data (Hyperion-FLAASH) but the results did not have any effect on the accuracy. Thus we anticipate that the 'Spectral Angle' can be one of the most accurate classifiers of not only multispectral images but also hyperspectral images. Furthermore the cluster unit vector can be an efficient technique for determination of each cluster mean in the USAC.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.254-259
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• 2005

Big fire such as mountain fire my cause the prevention of the functions of the overhead cables and insulators, which may affect the operation of the transmission lines. Therefore, in order to understand the effect of the mountain fire on the polymeric insulator for transmission lines, the author observed the deformation of the sheds of the polymeric insulators and the change of the discs of the porcelain insulators under fire, and investigated the electrical and mechanical characteristics of the insulators after the ignition test. As the result the following conclusions were obtained. First, the porcelain insulator was degraded in electrical characteristics when the insulator was subjected to the fire for approximately 5 minutes; whereas, the polymeric insulator was not degraded though there were some damage on its sheds. Second, after 20 minute exposure to the fire, the polymeric insulator lost a lot of parts of sheds, but the electrical characteristics was lowered by around 20%, but the porcelain insulators were electrically degraded by more than 80%.

• 한국군사과학기술학회지
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• 제12권2호
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• pp.199-205
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• 2009

A simple and effective analysis method is presented for predicting the best infiltration area. Based on geospatial information, numerical estimation barometer for degree of infiltration risk has been derived. The dominant geospatial features influencing infiltration risk have been found to be area altitude, degree of surface gradient, relative direction of surface gradient to the surveillance line, degree of surface gradient repetition, regional forest information. Each feature has been numerically expressed corresponding to the degree of infiltration risk of that area. Four different detection probability maps of infiltration risk for the surveillance area are drawn on the actual map with respect to the numerically expressed five dominant factors of infiltration risks. By combining the four detection probability maps, the complete picture of thr best infiltration area has been drawn. By using the map and the analytic method the effectiveness of surveillance operation can be improved.

• 전기전자학회논문지
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• 제23권4호
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• pp.1243-1249
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• 2019

특정한 이벤트나 콘텐츠를 즐기기 위해 모인 사람들을 관중 또는 관객이라고 하고, 모임의 특성에 따라 다양한 성향을 나타낸다. 그러한 차이점은 있지만, 일반적으로 관중 수는 경영적인 측면과 직결되는 요소로써, 관람료부터 다른 시설의 이용료 등 다양한 수입을 통해 콘텐츠 판매를 위한 안정적인 재정 운영을 가능케 한다. 따라서 관중 수에 대한 예측은 마케팅과 예산 전략 수립에 주요한 요소로 활용될 수 있다. 본 연구에서는 관중 수에 대한 예측을 위한 여러 가지 기존 모델을 검토하고, 그 중에서 효율적인 머신러닝 모델을 제안하고자 한다. 또한 딥러닝과 랜덤포레스트 모델을 혼용하여 일별 관중 수 예측과 비정상적 관중 수 예측에 대한 연구를 진행하였다.

• Journal of Biosystems Engineering
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• 제37권2호
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• pp.106-112
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• 2012

Purpose: A lab-scale timber carriage using a servo motor system was built. When two motors move a carriage, wire tension is changed according to the different line speeds caused by a wire drum's changing diameter, leading to inappropriate traveling characteristics of the carriage. In order to overcome this problem, PID Control was used to control the motor speed. Methods: Ziegler-Nichols method was used to determine PID gains. Results: The initial PID gains were 1.8, 0.025, and 0.006, respectively, and optimal gains of 1.4 and 0.010 for P and I gain were obtained experimentally. Conclusions: The results showed that constant wire tension could be maintained by controlling the speed of the motor using PI control. Overshoot occurred at initial motor operation due to vibration and elasticity of the wire itself.

• Korean Journal of Geomatics
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• 제5권1호
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• pp.27-34
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• 2005

Unsupervised classification is an important area of research in image processing because supervised classification has the disadvantages such as long task-training time and high cost and low objectivity in training information. This paper focuses on unsupervised classification, which can extract ground object information with the minimum 'Spectral Angle Distance' operation on be behalf of 'Spectral Euclidian Distance' in the clustering process. Unlike previous studies, our algorithm uses the unit vector, not the spectral distance, to compute the cluster mean, and the Single-Pass algorithm automatically determines the seed points. Atmospheric correction for more accurate results was adapted on the Hyperion data and the results were analyzed. We applied the algorithm to the Hyperion and ETM+ data and compared the results with K-Means and the former USAM algorithm. From the result, USAM classified the water and dark forest area well and gave more accurate results than K-Means, so we believe that the 'Spectral Angle' can be one of the most accurate classifiers of not only multispectral images but hyperspectral images. And also the unit vector can be an efficient technique for characterizing the Remote Sensing data.

• 건축역사연구
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• 제10권1호
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• pp.25-40
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• 2001

Since the 17th century, the society of Chosun Dynasty belonged to a period of rapid transition in many fields. As the building is a result produced on the basis of a society and economy, the general transition in a society is to be reflected into a process of building construction. Therefore an understanding or estimate of a building can be guaranteed by research of a process of building construction. Economic base factors in its process consist of material, cost, manpower, and operation system, etc. to be committed to the construction. On the premise, this paper is to examine the production of wood members and the calculation of the amount of raw woods in a process of woodwork in the construction of the government managed buildings in the late of Chosun dynasty. Construction reports, job slips, written estimates, and other documents in those days are examined for the study. To classify raw woods according to a standard size was aimed to a material management appropriately to apply each them to building size or its member size. The way to select a list of raw woods applicable to each member size, and to calculate the amount of the demanded wood was much more improved with 'Injungjeon-yeongkweon' in the year 1805 at the turning point than 'Hwaseong-seongyuk' in the year 1796. The improvement of material management brought to overcome a shortage of the amount supplied from forest preserve, and to a rationalization of building construction.

• 한국군사과학기술학회지
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• 제15권5호
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• pp.687-698
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• 2012

LADAR systems can rapidly acquire 3D point clouds by sampling the target surfaces using laser pulses. Such point clouds are widely used for diverse applications such as DSM/DTM generation, forest biomass estimation, target detection, wire avoidance and so on. Many kinds of LADAR systems have been developed with their respective purposes and applications. Particularly, Geiger mode imaging LADAR systems are increasingly utilized since they are energy efficient thank to extremely sensitive detectors incorporated into the systems. The purpose of this research is the performance assessment of a Geiger mode imaging LADAR system based on simulation with the real system parameters. We thus developed a simulation method of such a LADAR system by modeling its geometric, radiometric, optic and electronic aspects. Based on the simulation, we performed the performance assessment of a newly designed system to derive the outlier ratio and false alarm rate expected during its operation in almost real environment with reasonable system parameters. The proposed simulation and performance assessment method will be effectively utilized for system design and optimization, and test data generation.