• Geomechanics and Engineering
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• 제11권1호
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• pp.41-58
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• 2016

This paper focuses on the deformation behavior of tunnels crossing a weak zone in conventional tunneling. A three-dimensional finite element model was adopted that allows realistic modeling of the tunnel excavation and the support installation. Using the 3D FE model, a parametric study was conducted on a number of tunneling cases with emphasis on the spatial characteristics of the weak zone such as the strike and dip angle, and on the initial stress state. The results of the analyses were thoroughly examined so that the three-dimensional tunnel displacements at the tunnel crown and the sidewalls can be related to the spatial characteristic of the weak zone as well as the initial stress state. The results indicate that the effectiveness of the absolute displacement monitoring data as early warning indicators depends strongly on the spatial characteristics of the weak zone. It is also shown that proper interpretation of the absolute monitoring data can provide not only early warning for a weak zone outside the excavation area but also information on the orientation and the extent of the weak zone. Practical implications of the findings are discussed.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.49-50
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• 2015

Since the mid-2000s, Korean large-sized construction companies have pursued in earnest to expand their business to global construction market in surroundings that domestic market have a continuous and long-term stagnation. However, during last a few years, they have experienced the serious financial loss from international projects. In the meantime, for the sound improvement of Korean construction industry, many stakeholders long for efficient early warning signals to generally monitor and track the potential risks of international projects. In this study, we introduce an International Project Risk Index (IPRI), which is derived from massive data provided by large-sized companies, and expect to provide the practitioners and decision makers as an aid to proactively cope with the change of the potential risks. The outcomes from the IPRI can be utilized to prepare a timely management strategy and to establish an appropriate government support regulation.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.52-55
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• 2006

It's used to be said that tsunami is a rare event. The recurrence time of tsunami in Sumatra area is approximately 230 years as CalTech Research Group‘s study from paleocoral. However, the tsunami occurred in Indian Ocean on 26 December 2004, 28 March 2005 and 17 July 2006, because the earthquakes still release the energy. To cope with the tsunami disaster, we have to put the much effort on better disaster preparedness. The Tsunami Reduction Of Impacts through three Key Actions (TROIKA) was suggested by Eddie N. Bernard, the director of NOAA/PMEL (Pacific Marine Environmental Laboratory). They are Hazard Assessment, Mitigation and Warning Guidance. The satellite remote sensing has potential on these actions. The medium and high resolution satellite data were used to assess the degree of damage at the six-damaged provinces on the Andaman seacoast of Thailand. Fast and reliable interpretation of the damage by remote sensing method can be used for inundation mapping, rehabilitation and housing plans for the victims. For tsunami mitigation, the satellite data can be used with GIS to construct the evacuation map (evacuation route and refuge site) and coastal zone management. It is also helpful for educational program for local residents and school systems. Tsunami is a kind of ocean wave, therefore any satellite sensors such as SAR, Altimeter, MODIS, Landsat, SPOT, IKONOS can detect the tsunami wave in 2004. The satellite images have shown the characteristics of tsunami wave approaching the coast. For warning, satellite data has potential for early warning to detect the tsunami wave in deep ocean, if there are enough satellite constellation to monitor and detect the first tsunami wave like the pressure gauge, seismograph and tide gauge with the DART buoy can do. Moreover, the new methods should be developed to analyse the satellite data more faster for early warning procedure.

• Smart Structures and Systems
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• 제21권5호
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• pp.695-703
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• 2018

Based on monitoring data collected from the Nanjing Dashengguan Bridge over the last five years, this paper systematically investigates the effects of temperature field and train loadings on the structural responses of this long-span high-speed railway bridge, and establishes the early warning thresholds for various structural responses. Then, some lessons drawn from the structural health monitoring system of this bridge are summarized. The main context includes: (1) Polynomial regression models are established for monitoring temperature effects on modal frequencies of the main girder and hangers, longitudinal displacements of the bearings, and static strains of the truss members; (2) The correlation between structural vibration accelerations and train speeds is investigated, focusing on the resonance characteristics of the bridge at the specific train speeds; (3) With regard to various static and dynamic responses of the bridge, early warning thresholds are established by using mean control chart analysis and probabilistic analysis; (4) Two lessons are drawn from the experiences in the bridge operation, which involves the lacks of the health monitoring for telescopic devices on the beam-end and bolt fractures in key members of the main truss.

• 지질공학
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• 제16권2호
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• pp.171-178
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• 2006

현재 한국의 지진 관측은 1905년도에 시작된 이후로 계속적인 지진 관측망 확충과 새로운 장비의 도입으로 선진국 못지않은 장비를 보유하고 있지만, 지진의 관측과 분석에 있어서는 그 수준이 미흡한 것이 실이다. 특히, 동해안 지진원인자 분석에 있어서 시간이 많이 소요되기 때문에 지진 정보나 지진 해일 경보를 발령하는데 어려움이 있다. 이번 연구에서는 일본에서 사용하는 지진 관측망(JMA), 한국 지진 관측망(KMA), 그리고 국제 관측망(IRIS) 지진 관측소의 파형 포맷을 하나의 공통 파형 포맷으로 변환 합성하고 공유 분석 프로그램인 FESNET(극동 지진 관측망 분석 체계)를 구축하여 2004년 5월 29일과 6월 1일에 발생한 울진 지진과, 2005년 3월 20일에 발생한 일본 후쿠오카 지진의 분석에 응용하였다. 분석결과 어느 한쪽 관측망(KMA, JMA)을 사용하는 것보다 이들 모든 관측망을 활용하는 FESNET을 이용할 때 더 좋은 결과를 얻을 수 있다는 것을 말 수 있다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.295-298
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• 2014

2000년 이후 한국에서 기후변화(아열대성 및 잦은 이상기온) 및 농축산물 수입개방에 따른 국내 고병원성AI, 구제역, 가축질병 5회 발생으로 3조8천억원 피해와 기유입 확산되는 재선충의 10여년간 공적 방제비 2천383억원이 투입되었다. 또한 유입 가능성이 높은 흰개미 등의 외래식물해충으로 국가의 경제 사회적 피해와 영향이 증가되는 실정이다. 본 논문에서는 FTA확대에 따른 농식물로 인한 국가경제피해에 대한 대응 가능한 농업 농촌분야에 사물(IoT) 기반의 국가재난형 동 식물위성조기경보체계 운용전략에 대한 연구와 정책 수립을 연구한다. 또한 국가적 재난의 피해발생과 책임소재에 대한 정부의 피해보상 및 법 제도적인 책임 수행의 사전 증거자료 수집과 사후 보상 근거로서의 포렌식 기술이 포함된 정책이 적용되는 방법을 연구한다.

• 상하수도학회지
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• 제37권5호
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• pp.271-279
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• 2023

Fouling is an inevitable problem in membrane water treatment plant. It can be measured by trans-membrane pressure (TMP) in the constant flux operation, and chemical cleaning is carried out when TMP reaches a critical value. An early fouilng alarm is defined as warning the critical TMP value appearance in advance. The alarming method was developed using one of machine learning algorithms, decision tree, and applied to a ceramic microfiltration (MF) pilot plant. First, the decision tree model that classifies the normal/abnormal state of the filtration cycle of the ceramic MF pilot plant was developed and it was then used to make the early fouling alarm method. The accuracy of the classification model was up to 96.2% and the time for the early warning was when abnormal cycles occurred three times in a row. The early fouling alram can expect reaching a limit TMP in advance (e.g., 15-174 hours). By adopting TMP increasing rate and backwash efficiency as machine learning variables, the model accuracy and the reliability of the early fouling alarm method were increased, respectively.

• Journal of Korean Biological Nursing Science
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• 제16권4호
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• pp.259-266
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• 2014

Purpose: The purpose of this study was to analyze risk factors in predicting medical patients transferred to Intensive Care Unit (ICU) on the general ward. Methods: We reviewed retrospectively clinical data of 120 medical patients on the general ward and a Modified Early Warning Score (MEWS) between ICU group and general ward group. Data were analyzed with multivariate logistic regression and the area under the receiver operating characteristic curves using SPSS/WIN 18.0 program. Results: Fifty-two ICU patients and 68 general ward patients were included. In multivariate logistic regression, the MEWSs (Odds Ratio [OR], 1.91; 95% confidence interval [CI], 1.32-2.76), sequential organ failure assessment score (OR, 1.28; 95% CI, 1.10-1.72), $PaO_2/FiO_2$ ratio (OR, 0.98; 95% CI, 0.98-0.99), and saturation (OR, 0.93; 95% CI, 0.88-0.99) were predictive of ICU transfer. The sensitivity and the specificity of the MEWSs used with a cut-off value of six were 80.8% and 70.6% respectively for ICU transfer. Conclusion: These findings suggest that early prediction and treatment of patients with high risk of ICU transfer may improve the prognosis of patients.

• 디지털콘텐츠학회 논문지
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• 제19권3호
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• pp.587-593
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• 2018

증후군감시는 감염병 발생 초기에 나타날 수 있는 임상적 증상 발생동향을 감시하여 감염병의 발생을 가능한 조기에 인지하기 위해 고안된 감시체계이다. 한국 질병관리본부에서는 응급실 기반의 증후군감시시스템을 개발하였으며, 현 시스템의 기능을 강화하고자 국외 증후군감시 조기경보시스템에 관한 문헌조사를 하였다. 본 논문에서는 국외 증후군감시 조기경보시스템 운영현황을 설명, 비교하여 한국의 응급실 기반 증후군감시를 위한 조기경보시스템의 개선에 필요한 근거자료를 마련하였다.

• 한국농림기상학회지
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• 제22권3호
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• pp.117-127
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• 2020

농촌진흥청 농업기상재해 조기경보시스템은 기상청으로부터 제공되는 기상정보를 활용하여 농장 단위로 상세 추정하고, 추정된 상세 기상정보를 바탕으로 작물의 생육 추정 및 생육이 진행됨에 따라 발생할 수 있는 기상 재해를 예측하여 사용자에게 미리 전달한다. 이들 예측 정보를 검증하기 위한 무인기상관측망을 연구 지역 내에 구축하였으며, 관측망으로부터 수집되는 기상 실황 자료의 실시간 웹 표출 시스템을 구축하였다. 기상관측장비로부터 수집되는 기상요소로는 기온, 습도, 일사량, 강우량, 토양수분, 일조시간, 풍속, 풍향 등이며, 1분단위로 수집 및 10분 간격으로 서버로 전송된다. 자료 표출 시스템은 기상관측장비로 부터 수집되는 1분 단위의 기상자료를 DB로 구축하는 1단계, 수집된 기상자료를 10분, 1시간, 1일 단위로 통계 분석하는 2단계, 수집 및 분석한 기상자료를 웹으로 표출하는 3단계로 구성된다. DB에 수집된 기상자료는 웹 페이지를 통해, 전체 지점 또는 1개 지점의 1분단위, 10분단위, 1시간 단위, 1일 단위로 조회할 수 있으며, CSV 포맷으로 다운로드 할 수 있다. 자료 표출 시스템 접속 URL은 http://aws.agmet.kr 이다.