• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.51-59
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• 2020

This study evalutated the risk of foodborne illness from Vibrio spp. (Vibrio vulnificus and Vibrio cholerae) through sea squirt consumption. The prevalence of V. vulnificus and V. cholerae in sea squirt was evaluated, and the predictive models to describe the kinetic behavior of the Vibrio in sea squirt were developed. Distribution temperatures and times were collected, and they were fitted to probabilistic distributions to determine the appropriate distributions. The raw data from the Korea National Health and Nutrition Examination Survey 2016 were used to estimate the consumption rates and amount of sea squirt. In the hazard characterization, the Beta-Poisson model for V. vulnificus and V. cholerae infection was used. With the collected data, a simulation model was prepared and it was run with @RISK to estimate probabilities of foodborne illness by pathogenic Vibrio spp. through sea squirt consumption. Among 101 sea squirt samples, there were no V. vulnificus positive samples, but V. cholerae was detected in one sample. The developed predictive models described the fates of Vibrio spp. in sea squirt during distribution and storage, appropriately shown as 0.815-0.907 of R² and 0.28 of RMSE. The consumption rate of sea squirt was 0.26%, and the daily consumption amount was 68.84 g per person. The Beta-Poisson model [P=1-(1+Dose/β)^-α] was selected as a dose-response model. With these data, a simulation model was developed, and the risks of V. vulnificus and V. cholerae foodborne illness from sea squirt consumption were 2.66×10^-15, and 1.02×10^-12, respectively. These results suggest that the risk of pathogenic Vibrio spp. in sea squirt could be considered low in Korea.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.297-301
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• 2011

최근에는 전 지구적으로 이상기후 현상이 빈번히 발생하고 있으며 이로 인해 과거와는 달리 예측하기 어려운 집중호우와 돌발강우에 따른 피해가 증가하고 있는 추세이다. 이러한 이상 강우현상에 의해 하천 및 주변의 내 외수의 수위 상승을 야기하며, 이로인해 제내지의 침수 위험성이 그 어느 때보다 높은 실정이다. 특히, 내수침수의 경우는 외수에 따른 범람보다는 내수배제 불량에 따른 침수 빈도와 범위가 증가되고 있는 상황이며, 이에 대한 대비가 절실히 요구되고 있다. 주기적으로 반복되는 내수침수에 의한 국민의 재산과 인명피해를 최소화하기 위해서는 침수피해 위험도가 높은 지역을 파악 관리하여야 하며, 지역의 주민에게도 지역의 특성을 주지시켜야 한다. 이와 함께 침수 발생시 피해 최소화를 위한 피난 경로와 피난 장소 등을 상세히 제공하여 신속한 재난 대처와 함께 인명과 재산의 피해를 최소화하여야 한다. 침수예상지도는 태풍이나 집중호우에 의한 침수 발생시 제방의 월류 및 붕괴, 내수배제 불량 등으로 인한 예상 침수지역을 강우빈도별로 나타내고, 침수면적과 깊이를 표현한 지도로서 방재형 국토관리의 정책결정과 침수 피해에 대한 대민 홍보의 수단으로 활용되고 있다. 국내에서도 홍수에 의한 피해가 나날이 커지고 국토의 개발에 따른 자연 재해가 많아짐에 따라 홍수에 의한 피해를 최소화하기 위한 노력의 일환으로 침수예상지도의 제작 및 관리 시스템의 필요성이 증대되고 있다. 본 연구에서는 지석천 유역의 태풍 및 집중호우에 의한 과거 침수실적을 조사하여 침수실적도를 작성하 였으며, 내 배수 불량에 따른 홍수빈도, 강우빈도별 침수예상도를 작성하였다. 이를 위해 현재 보편적으로 이용되고 있는 1차원 수리 수문 모델인 미 공병단의 HEC-HMS, HEC-RAS 모델과 내 배수 영향 검토를 위해 한국농어촌공사에서 개발된 GATE 프로그램을 이용하였다. 이렇게 계산된 연구 대상지역의 침수심과 침수면적을 GIS를 이용하여 침수예상도를 작성하였다.

• Knowledge Management Research
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• v.22 no.4
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• pp.71-85
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• 2021

The purpose of this study is to find out which artificial intelligence methodology is most suitable for creating a foreign exchange rate prediction model using the indicators of bond market and interest rate market. KTBs and MSBs, which are representative products of the Korea bond market, are sold on a large scale when a risk aversion occurs, and in such cases, the USD/KRW exchange rate often rises. When USD liquidity problems occur in the onshore Korean market, the KRW Cross-Currency Swap price in the interest rate market falls, then it plays as a signal to buy USD/KRW in the foreign exchange market. Considering that the price and movement of products traded in the bond market and interest rate market directly or indirectly affect the foreign exchange market, it may be regarded that there is a close and complementary relationship among the three markets. There have been studies that reveal the relationship and correlation between the bond market, interest rate market, and foreign exchange market, but many exchange rate prediction studies in the past have mainly focused on studies based on macroeconomic indicators such as GDP, current account surplus/deficit, and inflation while active research to predict the exchange rate of the foreign exchange market using artificial intelligence based on the bond market and interest rate market indicators has not been conducted yet. This study uses the bond market and interest rate market indicator, runs artificial neural network suitable for nonlinear data analysis, logistic regression suitable for linear data analysis, and decision tree suitable for nonlinear & linear data analysis, and proves that the artificial neural network is the most suitable methodology for predicting the foreign exchange rates which are nonlinear and times series data. Beyond revealing the simple correlation between the bond market, interest rate market, and foreign exchange market, capturing the trading signals between the three markets to reveal the active correlation and prove the mutual organic movement is not only to provide foreign exchange market traders with a new trading model but also to be expected to contribute to increasing the efficiency and the knowledge management of the entire financial market.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.624-635
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• 2019

Bird strike accidents, a collision between aircraft and birds, have been increasing annually due to an increasing number of aircraft operating each year to meet heavier demand for air traffic. As such, many airports have conducted studies to assess and manage bird strike risks effectively by identifying and ranking bird species that can damage aircraft based on the bird strike records. This study was intended to investigate the bird species that were likely to threaten aircraft and compare and discuss the risk of each species estimated by the single-matrix and multi-matrix risk assessment models based on the Integrated Flight Information Service (IFIS) data collected in Gimpo, Gimhae and Jeju Airports in South Korea from 2005 to 2013. We found that there was a difference in the assessment results between the two models. The single-matrix model estimated 2 species and 6 taxa in Gimpo and Gimhae Airports and 2 species and 5 taxa in Jeju Airport to have the risk score above "high," whereas the multi-matrix model estimated 3 species and 5 taxa in Gimpo Airport, 4 species and 5 taxa in Gimhae Airport, and 2 species and 3 taxa in Jeju Airport to have the risk score above "very high." Although both models estimated the similar high-risk species in Gimpo and Gimhae Airports, there was a significant difference in Jeju Airport. Gimpo and Gimhae Airports are near the estuary of a river, which is an excellent habitat for large and heavy waterbirds. On the other hand, Jeju Airport is near the coast and the city center, and small and light bird species are mostly observed. Since collisions with such species have little effect on aircraft fuselage, the impact of common variables between the two models was small, and the additional variables caused a significant difference between the estimation by the two models.

• Journal of the Korea Society for Simulation
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• v.20 no.3
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• pp.101-109
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• 2011

M&S in the field of national defense is a battle system has been highly spotlighted for obtaining weapon systems, analyzing and experimentation of battle effects to reduce costs, time, and risks. It is classified as Campaign, Mission, Engagement, and Engineering levels by detail of description. In engagements, many situations on the battle field which are really unpredictable are required to be considered on the view of diverse tactics. Thus, engagement simulation is in demand to use for forecasting real-world battle situations by inserting various components which consists of real engaging situations into virtual local battle field. While developing the engagement simulation, adopting the concept of agent-based simulation gives it benefits which are improved autonomy, composability, and reusability of entities. It means reducing the time, cost and effort to develop the simulations. This paper concentrates on the framework of multi-agent based engagement simulation using Cougaar Architecture.

• Fire Science and Engineering
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• v.25 no.6
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• pp.32-38
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• 2011

As the using rate of an explosive gas has been increased in the industrial site, the regional residents adjacent to the site as well as the site workers have frequently fallen into a dangerous situation. Damage caused by accident in the process using hydrogen gas is not confined only to the relevant process, but also is linked to a large scale of fire or explosion and it bring about heavy casualties. Therefore, personnel in charge should investigate the kinds and causes of the accident, forecast the scale of damage and also, shall establish and manage safety countermeasures. We, in Anti-Calamity Research Center, forecasted the scope of danger if break out a fire or/and explosion in hydrogen gas facilities of MLCC firing process. We selected piping leak accident, which is the most frequent accident case based on an actual analysis of accident data occurred. We select and apply piping leak accident which is the most frequent case based on an actual accident data as a model of damage forecasting scenario caused by accident. A jet fire breaks out if hydrogen gas leaks through pipe size of 10 mm ${\Phi}$ under pressure of 120 bar, and in case of $4kw/m^2$ of radiation level, the radiation heat can produce an effect on up to distance of maximum 12.45 meter. Herein, we are going to recommend safety security and countermeasures for improvement through forecasting of accident damages.

• Tunnel and Underground Space
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• v.18 no.5
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• pp.328-337
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• 2008

Quantifying the extent and characteristics of the excavation damage zone(EDZ) is important for the nuclear waste industry which relies on the sealing of underground openings to minimize the risk for radionuclide transport. At AECL's Underground Research Laboratory(URL) the Tunnel Sealing Experiment(TSX) was conducted and the tunnel geometry and orientation relative to the stress field had been selected to minimize the potential for the development of an EDZ. The extent and characteristics of the EDZ was measured using velocity profiling and permeability measurements in radial boreholes. The results from this EDZ characterization are used in this paper to evaluate a modeling fir estimating the extent of the EDZ. The methodology used a damage model formulated in the Universal Distinct Element Code and calibrated to laboratory properties. This model was then used to predict the extent of crack initiation and growth around the TSX tunnel and the results compared to the measured damage. The development of the damage zone in the numerical model was found to be in good agreement with the field measurements.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.2 s.21
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• pp.25-35
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• 2006

Recently seismic fragility analysis method has been widely used for the seismic probabilistic risk assessment of infrastructures such as nuclear power plants, buildings and bridges because of its probabilistic characteristics. Furthermore, this technique has been applied to large-scale social systems consisted of each infrastructures by combing GIS. In this paper, the applicability of this technique to domestic infrastructural systems was studied. The transportation network was selected as one of these domestic infrastructural systems. Example studies were peformed about Changwon city. Nonlinear time history analysis, with a maximal likelihood approach were conducted to establish the fragility curves of each infrastrucures (bridges). GIS analysis was also applied to the analysis of whole infrastructural systems. The results show that it is very useful to predict seismic probabilistic risk assessment of this domestic transportation network. However, it also shows that further studies such as more suitable damage criterion to domestic structure and precise nonlinear analysis techniques should be developed to predict more precise results.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.65-76
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• 2017

The purpose of this study was to present a prediction model that reflects crime risk area analysis, including factors and spatial characteristics, as a precursor to preparing an alternative plan for crime prevention and design. This analysis of criminal cases in high-risk areas revealed clusters in which approximately 25% of the cases within the study area occurred, distributed evenly throughout the region. This means that using a multiple linear regression model might overestimate the crime rate in some regions and underestimate in others. It also suggests that the number of deserted houses in an analyzed region has a negative relationship with the dependent variable, based on the multiple linear regression model results, and can also have different influences depending on the region. These results reveal that closure signs in a study area affect the dependent variable differently, depending on the region, rather than a simple or direct relationship with the dependent variable, as indicated by the results of the multiple linear regression model.

• Proceedings of the Korean Society of Computer Information Conference
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• 2024.01a
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• pp.27-28
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• 2024

고령화 사회가 도래함에 따라 낙상은 심각한 사회 문제로 대두되고 있다. 그러나 낙상 위험 예측 및 평가 도구의 한계가 여전히 존재하고 있어 정확하고 신뢰성 있는 낙상 평가 방법을 필요로 한다. 본 연구에서는 신체 다양한 부위에 부착되어 수집된 센서 데이터를 이용하여 낙상을 검출하고 낙상의 방향까지 실시간으로 분류하는 모델들을 구축 및 평가한다. 이는 낙상의 유형에 따른 신속한 조치가 가능하도록 한다.