• International Journal of Aeronautical and Space Sciences
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• 제8권2호
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• pp.126-131
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• 2007

In this paper, Monte Carlo Simulation (MCS) method was used as an uncertainty assessment tool for air flow, net thrust measurement. Uuncertainty sources of the net thrust measurement were analyzed, and the probability distribution characteristics of each source were discussed. Detailed MCS methodology was described including the effect of the number of simulation. Compared to the conventional sensitivity coefficient method, the MCS method has advantage in the uncertainty assessment. The MCS is comparatively simple, convenient and accurate, especially for complex or nonlinear measurement modeling equations. The uncertainty assessment result by MCS was compared with that of the conventional sensitivity coefficient method, and each method gave different result. The uncertainties in the net thrust measurement by the MCS and the conventional sensitivity coefficient method were 0.906% and 1.209%, respectively. It was concluded that the first order Taylor expansion in the conventional sensitivity coefficient method and the nonlinearity of model equation caused the difference. It was noted that the uncertainty assessment method should be selected carefully according to the mathematical characteristics of the model equation of the measurement.

• 한국터널지하공간학회 논문집
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• 제17권5호
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• pp.553-561
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• 2015

본 연구에서는 국내에 활발히 적용되기 시작한 쉴드 TBM 터널의 합리적인 유지관리를 위한 성능평가 기준을 제시하였다. 이를 위해 국내 외 성능평가 기준을 분석하였고, 국내 시공된 쉴드 TBM 터널에 대한 현장조사 및 정밀안전진단 보고서 분석을 통한 변상사례를 조사하여 성능평가 항목을 균열, 누수, 파손, 박리, 층분리 및 박락, 백태, 품질상태, 철근노출, 탄산화, 단차, 볼트상태, 배수상태, 지반상태, 접속부상태, 공동구 상태로 선정하였다. 또한 다중의사결정기법인 AHP 기법을 활용하여 선정된 성능평가에 대한 합리적인 가중치를 산정하였다.

• 한국방재학회 논문집
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• 제2권4호
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• pp.117-122
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• 2002

최근 국내외에서 지하철 공사현장 가스폭발, 지하 공동구 화재, 지하가 화재 폭발 등 지하공간에서의 사고가 다수 발생하고 있다. 이러한 사고는 재산의 손실 뿐 아니라 전력, 통신망 마비로 도시기능을 무력화시키고, 인명 피해의 대형화를 동반함으로서 도시민의 안전을 위협하고 있다. 따라서 지하공간 중 지하가의 사고 사례와 문헌 연구 및 실태를 조사, 검토하고, 운영 관리 단계에서 위험 요인을 도출하여 안전대책의 평가요소 및 화재예방평가 시스템을 제시하고자 한다.

• 대한원격탐사학회지
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• 제35권2호
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• pp.317-326
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• 2019

개발사업 및 관련 환경영향은 공간 위에서 이루어지므로 환경영향평가 과정에서는 공간정보의 활용이 필수적이다. 본 연구에서는 환경영향평가의 공간정보 활용을 확대하기 위해 산재된 공간정보를 인벤토리로 구축, 환경영향평가 과정에서 활용할 수 있도록 제시하고자 한다. 이를 위해 환경영향평가 과정에서의 공간정보 이용 현황과 공공의 정보시스템에서 제공하는 환경 관련 공간정보 목록을 조사하였다. 그리고 선행연구 분석을 통해 도출한 인벤토리 구축 방법론을 적용, 환경영향평가 시 활용할 수 있는 공간정보 목록을 작성하였다. 그 결과 환경영향평가 업무에서 활용중인 공간정보는 64개 항목으로 조사되었으며, 자료 활용성 및 연계 갱신 가능성을 토대로 환경영향평가에 활용 가능한 국토환경공간정보는 45개 항목으로 조사되었다. 최종적으로 중복 제거 및 항목 재구성을 통해 14개의 신규 항목을 포함한 총 49개 항목을 도출, 공간정보 인벤토리로 제시하여 공간정보 기반의 환경영향평가에 기여할 수 있도록 하였다.

• Journal of Positioning, Navigation, and Timing
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• 제3권4호
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• pp.131-141
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• 2014

Over the last decade, the Global Navigation Satellite System (GNSS) has been increasingly utilized as a meteorological research tool. The Korea Astronomy and Space Science Institute (KASI) has also been developing a near real-time GNSS precipitable water vapor (PWV) information management system that can produce a precise PWV for the Korean Peninsula region using GNSS data processing and meteorological measurements. The goal of this paper is to evaluate whether the precise point positioning (PPP) strategy will be used as the new data processing strategy of the GNSS-PWV information management system. For this purpose, quality assessment has been performed by means of a comparative analysis of the troposphere zenith total delay (ZTD) estimates from KASI PPP solutions (KPS), KASI network solutions (KNS), and International GNSS Service (IGS) final troposphere products (IFTP) for ten permanent GNSS stations in the Korean Peninsula. The assessment consists largely of two steps: First, the troposphere ZTD of the KNS are compared to those of the IFTP for only DAEJ and SUWN, in which the IFTP are used as the reference. Second, the KPS are compared to the KNS for all ten GNSS stations. In this step, the KNS are used as a new reference rather than the IFTP, because it was proved in the previous step that the KNS can be a suitable reference. As a result, it was found that the ZTD values from both the KPS and the KNS followed the same overall pattern, with an RMS of 5.36 mm. When the average RMS was converted into an error of GNSS-PWV by considering the typical ratio of zenith wet delay and PWV, the GNSS-PWV error met the requirement for PWV accuracy in this application. Therefore, the PPP strategy can be used as a new data processing strategy in the near real-time GNSS-PWV information management system.

• 정보과학회 논문지
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• 제42권10호
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• pp.1294-1302
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• 2015

현재까지 인간 시각 체계를 정확하게 반영하기 위한 이미지 평가 기법에 대한 연구가 많이 이루어져 오고 있다. SSIM은 인간의 시각 체계가 이미지의 구조적 정보에 예민하다는 점을 이용하여 구조적 정보를 이용하여 이미지를 평가하는 대표적인 인간 시각 체계를 만족시키는 평가 기법이다. 하지만 SSIM은 이미지의 색 차이를 반영하지 못하는 문제가 있다. 이러한 문제를 해결하기 위해, HSI 색 공간을 활용한 SHSIM 기법이 제안되었으나 두 컬러 이미지 간 인지적 색 차이를 충분히 반영하지는 못하고 있다. 본 논문에서는 CIE Lab 색 공간을 도입하여 대응 되는 픽셀들의 인지적 색 차이를 계산하여 이미지 평가에 활용하는 방법을 제안한다. 그리고 연구를 더 확장하여, SVM 분류기를 활용하여 왜곡 종류에 따라 최적의 평가 수식을 적용하는 최적화 시스템을 제안한다. 제안하는 기법을 평가하기 위해, 이미지 평가분야에서 가장 많이 알려진 LIVE 데이터베이스를 사용하였으며 네 종류의 평가 기준들을 이용하였다. 실험 결과에서는 제안하는 기법이 다른 기법들보다 인간 시각 체계와 더 상관성이 높다는 것을 보여준다.

• 한국재난정보학회 논문집
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• 제6권1호
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• pp.92-119
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• 2010

As the necessity to utilize deep-placed underground spaces is increasing, we have to seriously consider the safety problems arising from the U/G spaces which is a restricted environment. Due to the higher cost of land compensation for above ground area and environmental issues, the plan to utilize deep-placed U/G spaces is currently only being established for the construction of U/G road network and GTX. However it is also expected that the U/G spaces are to be used as a living space because of the growing desires to change the above ground areas into the environmentally green spaces. Accordingly it is necessary to protect the U/G environments which is vulnerable against desasters caused by fire, explosion, flooding, terrorism, electric power failure, etc. properly. We want to introduce the principles of the Quantitative Risk Assessment(QRA) method for preparedness against the desasters arising from U/G environments, and also want to introduce an example of QRA which was implemented for the GOTTHARD tunnel which is the longest one in Europe.

• 산업경영시스템학회지
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• 제45권3호
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• pp.197-203
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• 2022

Urban space expansion is an important symbol of the urbanization process and has always been an important topic in urban studies. In addition, for sustainable city management, it is important to identify factors that can influence, such as the driving force and direction of urban space expansion, from the stage of establishing an urban development plan. To understand these factors, by observing the expansion process of a specific city, it is possible to sufficiently observe how the urban spatial dimension changes. Through a series of processes, the spatial growth characteristics of the city are analyzed, and the influence and results of important factors are analyzed. For this purpose, this paper examines the changes in the city's outer boundary and land use structure through monitoring data on urban areas of 14 cities in Hunan Province, China from 2000 to 2016. Temporal and spatial regularity according to the urban space expansion of these cities were analyzed, and a preliminary assessment was made on whether the urban space expansion is coordinated with the urban population growth. The assessment result showed: (1) The urban space of most cities has been extended rapidly in 2000-2015 however, the rate and the intensity of urban space expanding has been declining. (2) The construction of the industrial park is the core driving force of the urban space expanding, and the change of the urban space structure is manifested as enclave city expansion because that the industrial park is usually far away from the city center. (3) The population agglomeration is another driving force of the urban space expanding. At this time, the urban space expanding is like boundary extension. (4) Except Changsha city, all of the cities has a high urbanization-area-growth elastic coefficient. It means that most of the cities should enhance the land use degree.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권4호
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• pp.274-278
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• 2021

Road structures play an important role in collisions involving vehicles and wildlife. Our study aimed to determine the effect of various types of road structures on the risk associated with roadkill. We surveyed 50 previously identified roadkill hotspots, ranked from one to five according to roadkill density. We collected nine types of road structure data on each hotspot road section. Structures with similar characteristics were grouped together, resulting in five categories, namely, median barrier, high edge barrier, low edge barrier, speed, and visibility. We examined the existence of each road structure category at each hotspot rank. The cumulative link model showed that the absence of bottom blocked median barrier increased the roadkill hotspot rank. Our study concluded that a visual obstacle in the middle of roads by the median barrier decreases wildlife road crossing attempts and roadkill risk. We suggest that future roadkill mitigation plans should be established considering these characteristics.

• 우주기술과 응용
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• 제2권2호
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• pp.169-186
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• 2022

본 글에서는 러시아의 우주위협 평가와 러시아-우크라이나 전쟁(러시아의 우크라이나 침공)의 우주전을 분석하고 양상에 대해 정리하였다. 우주전의 양상이 상용위성 또한 잠재적인 공격 대상이 될 개연성을 고려하여 우주기술 개발시 군용위성뿐만 아니라, 상용위성도 우주위협에 대비할 수 있는 우주기술을 개발하고 동일하게 적용해야 함을 제언하고 적용이 필요한 우주기술에 대해 열거하였다.