• Journal of Korean Society on Water Environment
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• v.35 no.6
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• pp.589-597
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• 2019

The purpose of this study was improve accuracy the IOPs inversion model(IOPs-IM) developed in 2016 for phycocyanin(PC) concentration estimation in the Nakdong River. Additionally, two optimum models were developed and evaluated with 2017 measurement field spectral data for the Geum River and the Yeongsan River. The used measurement data for IOPs-IM analyzation was randomly classified as training and verification materials at the ratio of 2:1 in all data sets. Using the training data set from 2015-2017, accuracy results of the IOPs-IM generally improved for the Nakdong River. The RMSE(Root Mean Square Error) decreased by 14 % compared to 2016. For the GeumRiver, the results of the IOPs-IM were suitable, except for some point results in 2016. Results of the IOPs-IM in the Yeongsan River followed the overall 1:1 line and MAE(Mean Absolute Error) was lower than other rivers. But the RMSE and MAE values were higher. As a result of applying the validation data to the IOPs-IM, the accuracy of the Nakdong River was reduced to RMSE 17.7 % and MRE 16.4 %, respectively compared with 2016. However, the MRE(Mean Relative Error) was estimated to be higher by 400 % in the Geum River, and the RMSE was more than 100 mg/㎥ of the Yeongsan River. Therefore, it is necessary to get the continuously data with various sections of each river for obtain objective and reliable results and the models should be improved.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.3
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• pp.181-194
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• 2017

This study aims to develop a regression model for forest volume estimation using field-collected forest inventory information and airborne LiDAR data. The response variable of the model is forest stem volume, was measured by random sampling from each individual plot of the 30 circular sample plots collected in Bonghwa-gun, Gyeong sangbuk-do, while the predictor variables for the model are Height Percentiles(HP) and Height Bin(HB), which are metrics extracted from raw LiDAR data. In order to find the most appropriate model, the candidate models are constructed from simple linear regression, quadratic polynomial regression and multiple regression analysis and the cross-validation tests were conducted for verification purposes. As a result, $R^2$ of the multiple regression models of $HB_{5-10}$, $HB_{15-20}$, $HB_{20-25}$, and $HBgt_{25}$ among the estimated models was the highest at 0.509, and the PRESS statistic of the simple linear regression model of $HP_{25}$ was the lowest at 122.352. $HB_{5-10}$, $HB_{15-20}$, $HB_{20-25}$, and $HBgt_{25}-based$ models, thus, are comparatively considered more appropriate for Korean forests with complicated vertical structures.

• Journal of Environmental Impact Assessment
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• v.26 no.4
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• pp.242-256
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• 2017

In this paper, dispersion scenarios concerning various meteorological conditions and real urban structures were made to estimate the impacts of hazardous substance leakage accidents and to reduce damages. Based on the scenario of the hazardous substance dispersion, the characteristics of the risk in the pedestrian environment were analyzed in Gangnam, Seoul. The scenarios are composed of 48 cases according to the meteorological conditions of wind direction and wind speed. In order to analyze the dispersion characteristics of the hazardous substances, simulations were conducted using a computational fluid dynamic (CFD) model with hydrogen fluoride releases. The validation for the simulated wind was conducted at a specific period, and all the calculated verification indices were within the valid range. As a result of simulated dispersion field at pedestrian level, it was found that the dispersion pattern was influenced by the flow, which was affected by the artificial obstacles. Also, in the case of the weakest wind speed of the inflow, the dispersion of the hazardous substance appeared in the direction of the windward side at the pedestrian level due to the reverse flow occurred at lower layers. Through this study, it can be seen that the artificial structures forming the city have a major impact on the flow formed in urban areas. The proposed approach can be used to simulate the dispersion of the hazardous substances and to assess the risk to pedestrians in the industrial complexes dealing with actual hazardous substances in the future.

• Journal of the Korea Convergence Society
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• v.7 no.3
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• pp.99-109
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• 2016

The purpose of this study is to offer evidence that supports effective prevention strategies for people with chronic lifestyle related disease and cardiovascular disease based on understanding relations between health related behaviors and risk factors of metabolic syndrome, to suggest a basic indicator that are related to office workers' chronic lifestyle related disease and to provide basic information for educating people who are diagnosed with chronic lifestyle diseas.Research methods include SPSS / Win Program ver 20.0 utilization analyzes were, variables and relationships to analyze it to F-test verification and ANOVA test conduct was, associations verify the order $x^2$(Chi-square) validation was conducted.Participants of this study are office workers who took medical examination covered by employee health insurance athealth screening centers in the city of Seoul. All 291 participants were explained about the purpose of this study and signed consent forms. The prevalence of metabolic syndrome for 291 participants is 19.2 %. The prevalence of metabolic syndrome for a non-smoker group is 12.7 %, for a group of people who used to smoke lightly is 25.0 %, for a group of people who used to smoke heavily is 25.9 %, for light smokers group is 29.7 % and heavy smoker group is 26.7 %. As results of this convergence study exhibits, there is a strong correlation between smoking and drinking habits, and the prevalence of metabolic syndrome.

• Therapeutic Science for Rehabilitation
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• v.7 no.2
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• pp.51-61
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• 2018

Objective: The purpose of this study was performed to modify the performance-based assessment tool, Melbourne Low-Vision ADL Index (MLVAI) had been developed in Australia to suit the Korea culture to verify the reliability and validity. Methods: The subjects were only over the age of 20 living in communities, 26 with low-vision and 42 normal persons. The Korean MLVAI was completed through the expert translation verification and validation of the configuration tool. The validity of the Korean MLVAI was established through the content, discriminant, and convergent validity. Also, the reliability was analyzed through internal consistency reliability for the items, test-retest, and interrater reliability. Results: The Content Validity Index(CVI) was more than .78. There was a statically significant low in low-vision. Also, there was a statically significant low in low-vision. The convergent validity was determined the correlation coefficient of .751 analyzing LVQOL and Korean MLVAI total score, had a significant correlation(p<.05). Cronbach's ${\alpha}$ coefficient indicated an internal consistency of .983(p<.05). Test-retest reliability had a high, significant correlation of .976 and interrater reliability had a high, an intraclass correlation coefficient of .91(p<.05). Conclusion: The results of this study mean that the Korean MLVAI which was modified to fit the Korean is the ADL assessment tool with both validity and reliability. Based on this study, the Korean MLVAI can be used as a useful ADL assessment for OT interventions in low vision.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.597-606
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• 2020

Because the USV(Unmanned Surface Vehicle) is capable of remote control or autonomous navigation at sea, it can secure the superiority of combat power while minimizing human losses in a future combat environment. To plan the technology for the development of USV, the trend analysis of related technology and the selection of promising technology should be preceded, but there has been little research in this area. The purpose of this paper was to measure and evaluate the technology trends quantitatively. For this purpose, this study analyzed the technology trends and selected promising/declining technologies using topic modeling of papers and patent data. As a result of topic modeling, promising technologies include control and navigation, verification/validation, autonomous level, mission module, and application technology, and declining technologies include underwater communication and image processing technology. This study also identified new technology areas that were not included in the existing technology classification, e.g., technology related to research and development of USV, artificial intelligence, launch/recovery, and operation, such as cooperation with manned and unmanned systems. The technology trends and new technology areas identified through this study may be used to derive key technologies related to the development of the USV and establish appropriate R&D policies.

• Journal of Digital Convergence
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• v.11 no.6
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• pp.299-309
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• 2013

The purpose of this study was to develop the method of distinction for sports gifted children, which evaluated as well as cognitive capability and physical fitness. For the validation verification of developed method, we measured physique, physical fitness and developed cognitive agility method for 369 children from 2nd grade to 6th grade. Results were followed as below: The frequency of success of sports gifted group was higher than normal group(p<.05). Total time for cognitive agility of gifted child's group in both sex were shorter than normal group(p<.05). There were no significant correlation between physique and cognitive agility time. 50m run and side step test had correlation with cognitive agility time in boys and girls(p<.05). In spatial skills, only higher tendency in sports gifted group showed. Cognitive agility had positive correlation with space perception in both boys and girls of upper grades. With theses results, we concluded that developed cognitive agility test might be synthetic evaluated method for cognitive agility as qualitative capacity for boys and girls in elementary school.

• Journal of the Korean Geotechnical Society
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• v.32 no.4
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• pp.5-14
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• 2016

Numerical simulation of dynamic soil-pile-structure interaction embedded in a dry sand was carried out. 3D model of the dynamic centrifuge model tests was formulated in a time domain to consider nonlinear behavior of soil using the finite difference method program, FLAC3D. As a modeling methodology, Mohr-Coulomb criteria was adopted as soil constitutive model. Soil nonlinearity was considered by adopting the hysteretic damping model, and an interface model which can simulate separation and slip between soil and pile was adopted. Simplified continuum modeling (Kim et al., 2012) was used as boundary condition to reduce analysis time. Calibration process for numerical modeling results and test results was performed through the parametric study. Verification process was then performed by comparing numerical modeling results with another test results. Based on the calibration and validation procedure, it is identified that proposed modeling method can properly simulate dynamic behavior of soil-pile system in dry condition.

• Proceedings of the ESK Conference
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• 1996.10a
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• pp.171-178
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• 1996

CFMS(Critical Function Monitoring System)는 원자력발전소의 비상시에 운전원에게 보조장보를 제공하는 지원시스템이다. 본 연구에서는 원자력발전소 울진 3&4호기 CFMS의 화면설계에 대한 인간 공학적 검토를 수행하였다. CFMS에 대한 규제 및 법규를 만족시키는 것과 CFMS 화면설계가 운전원에게 편의성을 제공할 수 있는지에 대한 인간공학적 타당성 평가의 사례를 제시하고자 한다. 본 연구에서는 인간공학적 검토의 공식적인 체계를 설정하기 위하여, CFMS 설계에서 필요한 인간공학 업무를 규정하고 수행절차를 기술하는 인간공학 프로그램 계획 (Human Factors Engineering Program Plan; HFEPP)과 설계평가의 방법과 업무 내용을 기술하는 확인 및 검증 프로그램 계획(Human Factors Engineerign Verification and Validation Plan; HFE V&V Plan)을 개발하였다. CFMS 설계에 대한 인간공학적 확인 및 검증을 위하여 CFMS의 정보 가용성 (information availability)과 화면 적합성 (display suitability)을 확인하였다. 정보 가용성의 확인은 CFMS 설계 요건서에서 정의된 정보를 중심으로 한 필요정보의 목록과 CFMS 화면상에서 제공되는 정보의 목록을 비교함으로써 수행되었다. 화면 적합성의 확인은 검토항목 선정, 검토양식 개발, 전문가 검토, 실험검토 등의 과정을 통하여 수행되었다. 관련 규제 문건으로 부터 규제요건상 만족해야할 최소한의 검토항목을 선정하고 검토양식을 개발하였으며, 인간공학 전문가들의 주관적 평가를 통하 여 수행되었다. 또한 화면의 조작방식에 대한 상세검토를 수행하였다. 검토결과로부터 발견된 문제점들은 HED (Human Engineerign Discrepance) 목록으로 정리하여 설계에 반영하도록 하였다.로 마음의 안정감, 몸의 긴장 이완에 따른 건강 상태 유지, 수업 집중도 향상 등이 나타났다. 위와 같은 종합 적 분석 결과에 따라, 본 연구는 제조 현장의 생산성 향상 및 품질 향상과 연계하여 작업자의 작업 집중도 향상, 작업자의 육체적, 심리적 변화에 따른 생산성 및 품질 향상 변화 정도 등의 산업공학(인간공학) 제 분야의 여러 측면에서 연구 및 적용이 가능하리라 사료된다.l, 시험군:25.90$\pm$7.16mg/d1, 47% 감소)를 나타내었으며, 시험군의 AUC는 대조군에 비해 39% 감소하였고, 혈중 아세트알데히드의 농도는 투여 60분후 시험군(3.96$\pm$0.07nmo1/$m\ell$)이 대조군(6.45$\pm$0,64nmo1/$m\ell$)에 비해 유의성 있는 감소(39%)를 나타내었으며, 시험군의 AUC는 대조군에 비해 48% 감소하였다 한편, 시험관내 에탄올 대사 효소에 대한 바이오짐의 효과를 검색해본 결과 바이오짐(2.0 $\mu\textrm{g}$/assay)에 의해 Aldehyde dehydrogenase(1.5unit/assay)의 활성이 14% 증가되었다. 본 연구의 결과로 볼 때, 비지니스 및 바이오짐은 음주 후 상승된 혈중 에탄을 농도 및 아세트알데히드의 농도를 현저히 감소시키는 효과가 있었다.량 보호 관리, 도시 소공원 개발, 역사 문화 공원 조성, 하천 공간 복원, 공원 시설 기능 개선, 이용 프로그램 개발, 공원 관리 개선, 환경 피해 녹지의 회복, 도시 환경 림 조성, 녹지 기능 증진, 도시 자연 경관 보전, 공원 녹지체계 구성, 공원 녹지 공급 균형, 주변 환경 녹화, 가로 녹화의 17개 시책을 제안하였다. 이러한 정책사업의 원활한 추진을 위해서는 기존의 관주도의 일방적인 공원 녹지 행정이 아닌 시민의 참여를 통

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.153-162
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• 2011

Composite box-girder with corrugated steel webs has been widely used in civil engineering practice as an alternative of conventional pre-stressed concrete box-girder because the efficiency of pre-stressing can be increased and weight reduction of superstructure can be achieved by replacing concrete webs as a corrugated steel webs. However, most of previous researches were limited in shear and flexural behavior of such girder so that the torsional behaviors of composite box-girder with corrugated steel webs are not fully understood yet and it needs to be investigated. Some of previous researchers developed the nonlinear theory for torsional analysis of composite box-girder with corrugated steel webs. However, their theories were developed by ignoring the tensile behavior of concrete. Thus, there are certain limitations in analysis of serviceability such as cracking moment and torsional stiffness of the girder. This paper presents the analytical model for torsional behavior of composite box-girder with corrugated steel webs considering tensile behavior of concrete. Based on the proposed analytical model, nonlinear torsional analysis program of composite box-girder with corrugated steel webs was developed. Then, for verification of validation of the developed model, test for the girder was conducted and the results were compared with those of analytical model. Finally, parametric study was conducted and the effects of tensile behavior of concrete on the torsional behavior of the girder were discussed.