• Journal of Environmental Impact Assessment
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• v.27 no.4
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• pp.353-366
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• 2018

The purpose of this study was assessment the quality of water by using the statistical analysis technique of the Water flow and water quality from January 2012 to December 2016 at the unit basin for total pollutant load management system (TPLMS) in the Imjin River. Water flow and water quality were monitored at an average of 8 day intervals, 11 parameters were used for correlation analysis, principal component analysis (PCA), factor analysis (FA), and cluster analysis (CA). The Hierarchical CA was classified into three according to the change of space, such as natural rivers, urban rivers, point with large influence of point pollution source, it was found that the type of contamination source the similarity of water quality affected the classification of cluster. Using one-way analysis of variance (ANOVA) and post-hoc Analysis, there were statistically significant differences between mean values among the clusters. Correlation analysis showed the correlation coefficient between $COD_{Mn}$ and TOC was 0.951 (p<0.01) and the correlation was statistically significantly higher. According to the result PCA and FA, 3 principal components can explaining 72% of the total variations in water quality characteristics and main factor was EC, $BOD_5$, $COD_{Mn}$, TN, TP and TOC indirect indicators of organic matter and nutrients were influenced. This study presented the regression equation obtained by applying the factor scores to the multiple linear regression analysis and concluded that the management Indirect indicators of organic matter and nutrients is important for water quality management in the Imjin River basin.

• Journal of Korea Water Resources Association
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• v.49 no.7
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• pp.589-597
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• 2016

In this study, we investigated the use of satellite-derived flow (SDF) signals and a data-based model for the estimation of outflow for the river reach where in situ measurements are either completely unavailable or are difficult to access for hydraulic and hydrology analysis such as the upper basin of Imjin River. It has been demonstrated by many studies that the SDF signals can be used as the river width estimates and the correlation between SDF signals and river width is related to the shape of cross sections. To extract the nonlinear relationship between SDF signals and river outflow, Artificial Neural Network (ANN) model with SDF signals as its inputs were applied for the computation of flow discharge at Imjin Bridge located in Imjin River. 15 pixels were considered to extract SDF signals and Partial Mutual Information (PMI) algorithm was applied to identify the most relevant input variables among 150 candidate SDF signals (including 0~10 day lagged observations). The estimated discharges by ANN model were compared with the measured ones at Imjin Bridge gauging station and correlation coefficients of the training and validation were 0.86 and 0.72, respectively. It was found that if the 1 day previous discharge at Imjin bridge is considered as an input variable for ANN model, the correlation coefficients were improved to 0.90 and 0.83, respectively. Based on the results in this study, SDF signals along with some local measured data can play an useful role in river flow estimation and especially in flood forecasting for data-scarce regions as it can simulate the peak discharge and peak time of flood events with satisfactory accuracy.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.104-110
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• 2015

This study deals with the roundabout accidents. The goal of this study is to develop the sideswipe accident models at roundabout. In the pursuing the above, this study gives particular attentions to collecting the data of geometric structure and accidents of 54 roundabouts in Korea and developing the Poisson and negative binomial regression models. The main results are as follows. First, sideswipe accident is analyzed to be the highest frequency that is 39.5% of total accident data. Second, Poisson models which is statistically significant is developed. Finally, traffic volume per approach($X_1$), number of circulatory roadway($X_3$), operation of parking lot($X_4$) and width of circulatory roadway($X_6$) are adopted as the common variables. This study might be expected to give some implications to the accident research on the roundabout.

• Journal of environmental and Sanitary engineering
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• v.10 no.1
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• pp.66-75
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• 1995

This survey is executed about the water quality and improvement measure of Imjin- river. The results are summarized as follows; 1 ) Ammonia nitrogen concentration in tap water was two times higher than drinking water standard. 2) The concentration of BOD in textile wastewater was 235ppm which is higher than wastewater distribution standard and leather wastewater showed high nitrogen concentration. 3) Water quality of the Imjin- river upstream was not in problem but that of Shin- stream showed somewhat high concentration in BOD, COD, and ammonia nitrogen. Especially the detected Cynide compound on the lower of Shin- stream implied seriously polluted condition. 4) The heavy metal in soil of the river bed was not detected but iron, zinc was detected to high concentration. 5) It Is urgently suggested to build more municipal sewage and sanitary treatment plants, and run dredging and river bed rearrangement project. 6) The Construction of the wastewater treatment complexes of relevant industries shall be propelled as soon as possible.

• Journal of KIBIM
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• v.5 no.2
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• pp.34-45
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• 2015

As buildings become larger and more complicated, construction costs have increased with a considerable effect on buildings' Life Cycle Cost (LCC). However, there has been little consideration on economic aspects in the selection of construction materials due to limited information on the materials and dependency in architects' experience and inefficiency in cost estimation, causing design changes, increase in maintenance cost, difficulty in budgeting, and decrease in building performance. To solve these problems, this study proposed a BIM-based material selection model which reflects the comprehensive economic efficiency of building materials. Our cost prediction model can estimates the material-related cost during the entire building life cycle. Furthermore, we implemented the proposed model in connection with BIM, which can analyze and compare LCC by material. Through the validation of the model, we could confirm the necessity of LCC-based material selection in comparison with the conventional cost-centered material selection.

• The Journal of Korean Medical History
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• v.20 no.1
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• pp.83-87
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• 2007

Since the beginning of mankind humans labored to survive, and during this process damages and illnesses developed and jeopardized their lives. Through this, the people came to know that touching seats of disease and wounds reduces or relieves the pain. Based on this, the people started to understand the technical process of stimulating the body with the hands and began to systemize it to use it for medical purposes. Chuna medicine was completed that way and this study is one that organizes information related to its history.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.189-193
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• 2005

기존의 회귀식을 사용하거나 새로 유도하여 사용하는 경우 모두 일반적으로 회귀분석의 특성을 간과하고 사용하는 경우가 종종 발생한다. 일반적으로 자료들에서 구해진 회귀식은 분명히 독립변수와 종속변수가 구분되어 유도되었음에도 불구하고 이 식을 사용함에 있어서는 간혹 그 구분을 무시하고 역으로 적용하는 경향이 있었다. 그러나, 독립$\cdot$종속변수가 서로 바뀌면, 연직거리의 잔차들로부터 유도되는 기존의 회귀분석에 의하여, 회귀식이 서로 달라지기 때문에 역으로 적용하여서는 안된다. 이를 해결하기 본 연구에서는 상호변수 최소자승 회귀분석법을 제안하였다. 이론적 내용을 검토를 위해 임진강 영평천의 영중수위표 지점의 2001-2003년의 유량측정자료와 수위-유량곡선을 비교 분석하였다. 결론적으로 상호변수 회귀분석을 사용하면, 기존의 잘못 사용해온 관행을 해소할 수 있을 것이다.

• Proceedings of the Korean System Dynamics Society
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• 2006.11a
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• pp.49-69
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• 2006

본 논문은 선행연구인 정회성${\cdot}$전대욱 (2005)의 모형을 중심으로 선행연구에서 미처 다루지 못한 체계 변화 및 모형 확장 등에 대해 다루고 있다. 선행연구에서는 우리나라의 참게 복원사업에 대한 개체수 동태모형(population dynamics)과 자원 경제학적 이론모형을 근거로 생태${\cdot}$경제 통합시스템에 대한 동태모형을 도출하고 이를 통해 실증분석을 수행하였는데, 본 논문에서는 이 통합 모형에 있어서 밀도 제약(density restriction)과 공식 행위(cannibalistic behavior), 주민참여에 의한 환경개선 등 일련의 가정들에 대한 확장을 통해 보다 일반화된 통합체계 및 시스템 다이내믹스 분석을 제시한다. 이와 같은 모형 확장 및 파라메터의 내생화 등은 관련 피드백 루프들의 변형과 추가 등을 의미하며, 이와 같은 변화를 포함한 확장 모델을 제시하고 분석함으로써 참게 복원사업에 대한 보다 폭넓은 논의를 제시하고자 한다.

• Journal of the Korean Society of Safety
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• v.25 no.4
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• pp.90-95
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• 2010

This study deals with the accident model of arterial link section in Cheongju. The objective is to develop the accident model of arterial link section using the logistic regression. In pursuing the above, the study uses the 258 accident data occurred at the 322 arterial link section. The main results are as follows. First, Nagellerke $R^2$ of developed accident model is analyzed to be 0.309 and t-values of variable that explains goodness of fit are evaluated to be significant. Second, the variables adopted in the model are AADT, the number of exit and entry. These variables are all analyzed to be statistically significant. Finally, the analysis of correct classification rate shows that the total accident of correct classification rate is analyzed to be 72.7% at the arterial link section.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1929-1934
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• 2007

본 연구는 2006년도 한강 유역의 유량측정 지점 중 임진강 6개 지점, 중랑천 및 왕숙천 5개 지점, 홍천강 및 섬강 4개 지점 총 15개 지점 유량측정성과에 대한 기본적인 성과분석과 더불어 수위-유량관계곡선식의 개발, 산정 유량의 연유출률 평가, 상 하류간 유량 비교, 직접유출률 평가, 평 저수위 동시유량 비교 등을 통하여 산정된 유량자료의 적절성의 검토와 유출특성을 검토하였다. 산정된 유출률은 $49.0%{\sim}117.7%$의 범위를 보였으며, 부분적으로 계기수위가 불안정했던 지점들을 제외한 나머지 지점들의 유출률은 그 지점들의 특성을 감안할 경우 비교적 안정적인 범위내의 유출특성을 보였다. 2005년도 유출률과 비교해 보면 전체적으로 다소 높게 나타났으나, 올해 장기간 집중된 강우 특성을 고려한다면 적절한 유출범위를 보인 것으로 판단된다.