• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.2
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• pp.42-54
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• 2011

This study presented an algorithm to detect zigzag driving maneuver that is highly associated with vehicle crash occurrence. In general, the zigzag driving results from the driver's inattention including drowsy driving and driving while intoxicated. Therefore, the technology to detect such unsafe driving maneuver will provide us with a valuable opportunity to prevent crash in the road. The proposed detection algorithm used angular velocity data obtained from a gyro sensor. Performance evaluations of the algorithm presented promising results for the actual implementation in practice. The outcome of this study can be used as novel information contents under the ubiquitous transportation systems environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1077-1085
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• 2020

In order to Mine Countermeasure (MCM), the search is carried out for the expected mine zone. At this time, mine hunting uses Autonomous Unmanned Vehicle(AUV), taking into account the danger of mine and the stability of our forces. Sonar system for identifying buried mines are equipped with Side Scan Sonar(SSS) or Synthetic Aperture Sonar(SAS). This paper describes the analysis of mine hunting effects according to the commercial SSS characteristics. Based on the characteristics of each SSS, the insonified area and recognition probability were modeled, and the analysis was performed according to the search pattern of the AUV. AUV's search pattern defines three patterns depending on the presence or absence of SSS or shaded areas. The analysis results derived search time and detection probability for each search pattern, and finally, the improvement of search depending on the presence or absence of side injection or shaded area.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.199-207
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• 2016

This study was conducted to develop a forest fire occurrence model using meteorological characteristics for practical forecasting of forest fire danger rate by reflecting the climate change for the time period of 2000yrs. Forest fire in South Korea is highly influenced by humidity, wind speed, temperature, and precipitation. To effectively forecast forest fire occurrence, we developed a forest fire danger rating model using weather factors associated with forest fire in 2000yrs. Forest fire occurrence patterns were investigated statistically to develop a forest fire danger rating index using times series weather data sets collected from 76 meteorological observation centers. The data sets were used for 11 years from 2000 to 2010. Development of the national forest fire occurrence probability model used a logistic regression analysis with forest fire occurrence data and meteorological variables. Nine probability models for individual nine provinces including Jeju Island have been developed. The results of the statistical analysis show that the logistic models (p<0.05) strongly depends on the effective and relative humidity, temperature, wind speed, and rainfall. The results of verification showed that the probability of randomly selected fires ranges from 0.687 to 0.981, which represent a relatively high accuracy of the developed model. These findings may be beneficial to the policy makers in South Korea for the prevention of forest fires.

• Economic and Environmental Geology
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• v.34 no.4
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• pp.385-394
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• 2001

There are serious damage of people and properties every year due to landslides that are occurred by heavy rain. Because these phenomena repeat and the heavy rain is not an atmospheric anomaly, the counter plan becomes necessary. The study area, Ulsan, is one of the seven metropolitan, and largest cities of Korea and has many large facilities such as petrochemical complex and factories of automobile and shipbuilding. So it is necessary assess the landslide hazard potential. In the study. the three steps of landslide hazard assessment techniques such as susceptibility, possibility, and risk were performed to the study area using GIS. For the analyses, the topographic, geologic, soil, forest, meteorological, and population and facility spatial database were constructed. Landslide susceptibility representing how susceptible to a given area was assessed by overlay of the slope, aspect, curvature of topography from the topographic DB, type, material, drainage and effective thickness of soil from the soil DB, lype age, diameter and density from forest DB and land use. Then landslide possibility representing how possible to landslide was assessed by overlay of the susceptibility and rainfall frequency map, Finally, landslide risk representing how dangerous to people and facility was assessed by overlay of the possibil. ity and the population and facility density maps The assessment results can be used to urban and land use plan for landslide hazard prevention.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.4
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• pp.83-91
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• 2000

합리적인 기기의 활률론적 지진위험도 평가를 위해서는 모델의 동특성에 대한 보다 현실적인 정보가 제공되어야 한다. 이 연구에서는 심한 비선형 동적 거동을 보일 것으로 예상되는 철제 전기 캐비넷의 동특성 시험결과 및 분석 절차를 제시하였다. 특히, 이 연구에서는 가진 강도의 크기에 따른 동특성의 비선형 집중분석하고, 그 비선형성의 원인을 고찰하였다. 시험 결과 및 이 논문에 제시된 분석 절차를 이용하여 시험체의 동특성이 효과적으로 도출될 수 있으며, 대상 시험체는 가진 강도에 따라 심한 비선형 거동을 함을 입증하였다. 비선형성의 원인은 일반적인 재료 비선형이라기 보다는 각 부품들의 마찰력과 기하학적인 비선형성에 기인함을 발견하였다. 또한, 캐비넷 형식의 기긱에 대한 합리적인 내진안전성 평가를 위해서는 각 방향별로 서로 다른 감쇠값을 적용할 것을 추천하였다. 또한, 캐비넷 형식의 기기에 대한 합리적인 내진안전성 평가를 위해서는 각 방향별로 서로 다른 감쇠값을 적용할 것을 추천하였다.

• Journal of Korean Society of Forest Science
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• v.80 no.3
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• pp.257-264
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• 1991

Korea has accomplished the afforestation of its forest land in the early 1980's. To meet the increasing demand for forest products and forest recreation, a development of scientific forest management system is needed as a whole. For this purpose the development of efficient forestfire management system is essential. In this context, the purpose of this study is to develop a theoretical foundation of forestfire danger rating system. In this study, it is hypothesized that the degree of forestfire risk is affected by Weather Factor and Man-Caused Risk Factor. (1) To accommodate the Weather Factor, a statistical model was estimated in which weather variables such as humidity, temperature, precipitation, wind velocity, duration of sunshine were included as independent variables and the probability of forestfire occurrence as dependent variable. (2) To account man-caused risk, historical data of forestfire occurrence was investigated. The contribution of man's activities make to risk was evaluated from three inputs. The first, potential risk class is a semipermanent number which ranks the man-caused fire potential of the individual protection unit relative to that of the other protection units. The second, the risk sources ratio, is that portion of the potential man-caused fire problem which can be charged to a specific cause. The third, daily activity level is that the fire control officer's estimate of how active each of these sources is, For each risk sources, evaluate its daily activity level ; the resulting number is the partial risk factor. Sum up the partial risk factors, one for each source, to get the unnormalized Man-Caused Risk. To make up the Man-Caused Risk, the partial risk factor and the unit's potential risk class were considered together. (3) At last, Fire occurrence index was formed fire danger rating estimation by the Weather Factors and the Man-Caused Risk Index were integrated to form the final Fire Occurrence Index.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1337-1348
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• 2017

In this paper, we develop the high-risk drinking predictive model in Korea using the cross-sectional data from Korea Community Health Survey (2014). We perform the logistic regression analysis, the decision tree analysis, and the neural network analysis using the data mining technique. The results of logistic regression analysis showed that men in their forties had a high risk and the risk of office workers and sales workers were high. Especially, current smokers had higher risk of high-risk drinking. Neural network analysis and logistic regression were the most significant in terms of AUROC (area under a receiver operation characteristic curve) among the three models. The high-risk drinking predictive model developed in this study and the selection method of the high-risk intensive drinking group can be the basis for providing more effective health care services such as hazardous drinking prevention education, and improvement of drinking program.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.87-87
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• 2021

이상기후 현상으로 기후변화가 사회와 경제에 미치는 영향이 뚜렷한 추세로 변화되고 있다. 현재 기후변화에 관련된 연구는 사회 시스템에서 위험관리를 위해 기온과 강수량에 따라 다양한 분야에 미치는 영향에 대한 연구를 중점으로 이뤄지고 있다. 본 연구는 여름철 폭염에 의한 기후변화가 하천수질에 미치는 영향을 평가하기 위한 것으로, 우리나라 기상청 91개의 기상관측소에서 일일온도 33℃ 이상의 이벤트를 대상으로 환경부 수질관측망 918개에 대한 14개의 하천수질인자인 DO, BOD, COD, TOC, DOC, TN, DTN, NH4-N, NO2-N, NO3-N, TP, DTP, PO4-P, Chl-a를 분석하였다. 이를 우리나라 117개 중권역별 하천수질과 폭염강도와 지속시간을 나타내는 폭염 지수를 산정하여 분석하였다. 폭염 관련 뉴스 데이터는 2013년부터 2019년까지 Python 기반 뉴스 크롤러를 이용해 폭염 취약지수(Heat Wave Vulnerability Index, HWVI)를 기준으로 분류하여 키워드를 수집하였으며 HWVI 중 '기후노출' 키워드와 관련된 기사는 총 22,514건으로 69.9%로 수집되었다. 공간적 영향 평가를 위해 Getis-Ord Gi*를 이용하여 폭염지수와 하천수질인자간 핫스팟 분석을 실시하고 폭염관련 빅데이터가 하천수질에 미치는 영향을 평가하였다. 폭염지수는 낙동강유역 하류에 대해 Chl-a, TN, TP 항목에서 높은 밀도를 보였다. 분석대상지역 내 폭염이 발생한 확률과 반경 밖에서 발생할 확률의 우도비를 분석하기 위해 SaTScan을 이용한 공간검색통계분석을 실시하였다. 분석결과 폭염지수와 DO의 공간상관성이 높은 것으로 나타났다.

• Korean Journal of Construction Engineering and Management
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• v.19 no.5
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• pp.53-60
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• 2018

In particular, the investigation of tendons in PSC Box Girder Bridge should be done in a systematic way. It is important to identify preventative maintenance activities that should be carried out in order to analyze the risk factors by type of representative tensions and to reduce risks in the long term. However, in the current maintenance system, various methodologies for investigating and repairing tensions have been studied, but it is difficult to investigate precisely tensions. Therefore, to apply the risk assessment for screening of tensions to the domestic PSC Box Bridge, we presented a risk matrix evaluation index that is consistent with the state assessment and maintenance system.

• Tunnel and Underground Space
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• v.18 no.6
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• pp.393-407
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• 2008

To protection of fire accident and to minimize danger of spreading the disaster. in railway tunnel, MCT (the Ministry of Construction and Transportation) published "Rules about the Safety Standard of Railroad (2005.10.27)" and "The Detailed Safety Standard of Railroad (2006.9.22)". QRA(Quantitative Risk Analysis) results are applied to establish the fire protection facilities in railway tunnel so that institute the reasonable application about the fire safety facilities However, it is difficult to perform the fire safety design due to lack of the detailed standards about event scenario, fire intensity, incidence rate of accidents etc. Therefore, This paper introduces the practical method about detailed standards of QRA.