• Journal of Digital Convergence
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• v.19 no.7
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• pp.271-282
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• 2021

This study was conducted to develop a model for predicting the length of stay for premature infants through machine learning. For the development of this model, 6,149 cases of premature infants discharged from the hospital from 2011 to 2016 of the discharge injury in-depth survey data collected by the Korea Centers for Disease Control and Prevention were used. The neural network model of the initial hospitalization was superior to other models with an explanatory power (R²) of 0.75. In the model added by converting the clinical diagnosis to CCS(Clinical class ification software), the explanatory power (R²) of the cubist model was 0.81, which was superior to the random forest, gradient boost, neural network, and penalty regression models. In this study, using national data, a model for predicting the length of stay for premature infants was presented through machine learning and its applicability was confirmed. However, due to the lack of clinical information and parental information, additional research is needed to improve future performance.

• Water for future
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• v.27 no.4
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• pp.95-104
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• 1994

The sinuosity model has been developed to simulate to developed to simulate the floodwave in meandering channels by solving the extended Saint-Venant equation with the Preissmann scheme. The suggested model is compared with three conventional floodplain routing methods in terms of governing equations, mass conservation error and floodwave analysis. The sinuosity model produces the mass conservation error of 1.5-1.8%, however the separate channel model produces 9.1% and 27.4% for sinuosity of 1.5 and 2.0, respectively. The model has been used to simulate flow in an idealized meandering river with a floodplain. The attenuation ratio and the travel time ratio are found to increase as the floodplain roughness and width increase and as the sinuosity factor decreases. The model is expected to contribute the floodwave analysis in sinuous channel with compound corss sections.

• Journal of Korean Society of Transportation
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• v.31 no.2
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• pp.69-79
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• 2013

This study suggests a specific methodology to analyze how emission impacts on regional emission concentrations in accordance with the change of weather conditions, and the need of its application. The suggested methodology was applied to a transportation network of Pochun area in Gyenggido as an example. The methodology contains two types of analytical models; 1) dispersion analysis based on emission from traffic, and 2) dispersion analysis based on the combination between emission from traffic and existing emission in the air. By doing so, it is expected that the comprehensive influence of emission on traffic network and its surrounding areas can be identified. In addition, it might be useful for us to apply environmental risk assessment based on the effect of emission on the people.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.1
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• pp.79-88
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• 1997

Very stiff floor system in a residential-commercial building causes some problems in the numerical analysis procedure due to significant difference in stiffness with adjacent elements. Static analysis of structure with a stiff transfer-floor can be performed approximately in two steps for upper and lower parts for the structure. However, it is impossible to perform dynamic analysis in two steps with separate models. An efficient method for dynamic analysis of a structure with a right floor system is proposd in this study. The matrix condensation technique is employed to reduce the degree of freedom for upper and lower parts of the structure and a beam elements with rigid bodies at both ends are introduce to model the rigid floor system. Efficiency and accuracy of the proposed method are verified through analysis of several example structures.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.106-106
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• 2017

우리나라는 현재 재난의 유형을 자연재난과 사회재난으로 구분하여 관리하고 있다. 하지만 최근 재난 사고 사례를 살펴보면 단일재난으로 인한 피해보다 자연재난이 발생한 이후 사회재난으로 재난이 전파되는 복합재난의 형태가 종종 나타나고 있다. 복합재난은 단일 재난에 의한 피해(인적, 물적) 보다 크게 나타나고 복합재난의 발생원인 및 전파과정을 분석하기 어려워 이에 대한 다각적인 분석과 동시에 재난상호간의 연관성을 도출하는 연구가 필요한 시점이다. 과거 재난사고정보를 분석하는 연구는 일반적인 통계기법을 활용한 분석에 머물러 있으며 수집된 재난사고사례가 많지 않아 분석에 신뢰성을 보장할 수 없었다. 이에 본 연구에서는 복잡하게 나타나는 재난 사고를 분석하기 위하여 최근 각광받고 있는 인공지능 분석기법을 연구에 고려하였다. 본 연구의 과정은, 첫째로 재난사고정보 분석에 인공지능을 활용한 사례를 조사하고 여타 연구분야에서 적용되고 있는 인공지능 분석기술을 재난사고정보 분석에 활용할 수 있는 방안을 모색하였다. 둘째로 수집가능 한 재난사고정보를 수집하고 인공지능 모형에 적용가능 한 형태로 변환하는 과정을 수행하였다. 셋째로 변환된 재난사고정보를 대표적인 인공지능 알고리즘을 활용하여 다양한 질문(목적)에 부합하는 재난사고정보 분석모형을 구축하고자 하였다. 마지막으로 다양한 인공지능 알고리즘을 적용한 모형의 신뢰성을 비교하였으며 이를 통하여 재난사고정보 분석에 적용가능 하며 질문(목적)에 부합하는 최적 인공지능 알고리즘을 도출하고자 하였다.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.401-409
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• 2020

The purpose of this study is to develop a convergence inpatient medical service patient experience management model(IMSPEMM) that can help in the management strategy of a medical institution to create a patient-centered medical culture. Using the original data from the 2018 Medical Service Experience Survey, 593 people with medical services inpatient(MSI) over the age of 15 were analyzed. By using the decision tree model, we developed a prediction model for overall satisfaction(OS) with the inpatient medical service experience(IMSE) and the intention to recommend patient experience(RI), and were classified into 4 and 7 types. The accuracy of the model was 68.9% and 78.3%. The OS level of IMSE was the nurse area and the hospital room noise management area, and the RI decision factor was the nurse area. It is significant that the IMSPEMM for MSI was presented and confirmed that the nurse area and the noise management area of the hospital room are important factors for the inpatient experience. It is considered that further research is needed to generalize the IMSPEMM.

• Journal of the military operations research society of Korea
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• v.36 no.3
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• pp.57-68
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• 2010

This Study proposes that a SoS(System of Systems) Conceptual Design Model which is developed for the SoS establishment, requirement and decision, utilizing SoS engineering and architecture methodology, and the Model performed with the Process Transition Map using subject matter expert survey. Establishing an Integrated Battle Experimentation System(IBES) for the future force development, the process product of IBES was conceptually designed using a SoS Conceptual Design Model.

• Journal of the Korean Data and Information Science Society
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• v.21 no.1
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• pp.1-9
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• 2010

This paper suggests a mixed-effects model for analyzing split-plot data when there is a repeated measures factor that affects on the response variable. Covariance structures are discussed among the observations because of the assumption of a repeated measures factor as one of explanatory variables. As a plausible covariance structure, compound symmetric covariance structure is assumed for analyzing data. The restricted maximum likelihood (REML)method is used for estimating fixed effects in the model.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1884-1888
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• 2009

군산복합화력발전소의 냉각수 취수부는 부지 여건상 수로의 길이가 짧고, 좌안이 좁아진 후 단차가 있는 형태에 직각으로 흐름방향이 전환되면서 CWP로 유입되는 구조로 설계되었기 때문에 CWP 운영에 불리한 수리현상이 예상되어 수치모의와 수리모형실험을 통한 사전검증이 필요하였다. 이에 $FLOW-3D^(R)$를 이용한 3차원 수치모의와 축척 1/10의 수리모형실험을 통하여 면밀히 검토한 결과 CWP 진입부의 깊은 수심이 흐름을 감세하여 0.3m/s 이하의 유속분포를 나타내 균등취수에 문제가 없는 것으로 확인되었다.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2013.10a
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• pp.153-167
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• 2013