• Journal of Korean Society of Forest Science
• /
• v.112 no.1
• /
• pp.32-39
• /
• 2023

Using the logarithmic methods and the generalized method of moments (GMM), this study developed carbon storage equations for maple trees (Acer palmatum Thunb.) planted in an urban settlement area. A total of 20 maple trees of various ages and diameters were destructively harvested to determine their dry weight and carbon concentration by component. The allometric equations with DBH and DBH²×H as independent variables were developed to estimate the carbon storage for each tree component. The carbon concentration of tree components was the highest in stem wood (49.8%) and lowest in stem bark (46.5%). Allometric equations to estimate the carbon storage of tree components (stem, root, aboveground, and total) showed a similar coefficient of determinations (R²) between the allometric equations of the logarithmic method (0.7494-0.9036) and the GMM (0.7085-0.8847). However, the R² values of the leaves and branches were in the range of 0.3027 to 0.6380, lower than those of the R² of the other tree components. These results indicate that the carbon storage of maple trees growing in urban settlement areas can be efficiently predicted from the equations of GMM methods in the case of a small sample size or the heteroscedasticity of logarithmic equations.

• Environmental and Resource Economics Review
• /
• v.31 no.1
• /
• pp.85-112
• /
• 2022

This study analyzed the influence of domestic and Chinese factors on fine dust(PM10 & PM2.5) in Korea by using the panel quantile regression. Daily analysis was conducted for 11 regions in Korea. For domestic factors, electricity demand and traffic volume, and for Chinese factors, interaction term of Chinese three cities' fine dust and the domestic west wind are used. As a result, the influence of domestic factors was different when the domestic fine dust concentration was high and low. When the fine dust concentration was low, electricity demand had a positive effect only on PM2.5, and didn't affect PM10 in the national analysis. In regional analysis, the amount of electricity demand had a significant effect on fine dust and ultrafine dust only in the capital area and Chungcheong. Electricity demand was found to significantly increase both PM2.5 and PM10 when it was high. On the other hand, it was confirmed that the Chinese factor always had a significant effect regardless of the concentration of PM10 and PM2.5. Therefore, in order to solve the problem of high concentration of fine dust, in addition to international cooperation, the reduction of PM2.5 generated by domestic thermal power generation should also be strengthened compared to the present.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.43 no.4
• /
• pp.485-492
• /
• 2023

Among the methods to improve traffic congestion by providing real-time traffic information and solving problems like traffic congestion and traffic crashes, private enterprise is implementing policies to lower insurance premiums like compensation for drivers' driving safety scores. Despite the emergence of various incentive policies, a study on the level of incentive payment for safe/eco-friendly driving is insufficient. The research analyzed the satisfactory factors that affect the scale of incentives through questionnaires and the applicable scale of incentives that enable safe/eco-friendly driving using a binary logistic regression model. As a result of analyzing the incentive scale of the appropriate payment amount for each driving score increase, 0.4% of the toll fee was derived when the driving score increased by 20 points, and 0.5% of the toll fee was derived when the driving score increased by 30 points. This study on calculating the appropriate incentive payment scale for driver information sharing and driving score increase will help optimize incentives and prepare system implementation plans.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.6D
• /
• pp.697-705
• /
• 2010

The purpose of this research is to clarify the relation between environmental consciousness and railway usage behavior. Author would locate this research on position of basic survey to promote railway use according to Low Carbon Green Growth policy in Korea. In this research, we would perform descriptive analysis using data of research on the actual condition of railway use in 2008, Daegu, and describe its relationship. In addition, we would suggest some idea about policy which can promote railway use. The order of railway choice behavior noticed in clustering of environmental consciousness was cooperative behavior type, middle type and non-cooperative behavior type. It suggests that environmental consciousness has effect on transportation choice behavior. Specially, railway improvement isn't enough to promote railway use. And, it is advisable to carry out the improvement in such a way that it may encourage the nation to move from the current environmental consciousness stage to cooperative behavior. Moreover, we assumed Binary Probit(BP) model using SP data of time or condition of transportation expense compared with passenger car and bus. As the results, modified likelihood ratio of two BP models is favorable variables. And it occurred that mode was transferred from passenger car to railway when it showed higher social environment consciousness and low selfish environment consciousness, because t-statistic which represents selfish environment consciousness showed significance in 95% confidence level. That is, it can be described that environment consciousness affect on the intention of railway use.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.5D
• /
• pp.723-734
• /
• 2008

In this paper, the problems and betterment plan in operating district units plan are studied by selecting typal case locations based on the types of district units plan of the city of Busan. According to the types, 4 locations of 'type of maintaining preexisting district' and 3 of 'type of managing preexisting district' are selected as case locations, based on a scale and characteristics of each location.In systematical aspects of the case locations, indiscreet upward adjustment of the locations, insignificant participation of the citizens and patternization were recognized as problems. And setting accurate standards for target and range of alteration in line with usage plan of the locations would be necessarily urgent. So through the analysing process of the problems arisen from the case locations I would suggests necessary solutions to improve the effectiveness of the district units plan. And In planning aspects, the similarity between the basic directions and the object, batch-application of the density plan, inadequacy of the usage plan, allocations and patterns of structures, and color planning were recognized to have problematic points. Consequently distinguished specific operating-guidelines would be necessary to achieve the basic directions and the object of district units plan. Furthermore, the building-to-land ratio and floor space index are needed to be exactly calculated through providing accurate and logical standards for appropriate development density of structures.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.234-234
• /
• 2022

도로에서의 우수를 원활하게 처리하기 위해서 빗물받이 및 연결관 등의 노면 배수시설이 설치되고 있으며, 노면 배수는 측구부를 통해 흘러 빗물받이 유입부로 차집되고 연결관을 통해 하수관거로 배수된다. 그러나 최근 국내 기상패턴의 변화로 국지성 집중호우와 같이 시간당 강우량 증가로 도로부와 저지대에서 배수시설의 배수불량에 따른 도심지 내수침수 피해가 발생하고 있다. 이에 정부에서는 다양한 우수관거 개선사업, 빗물펌프장, 지하저류조와 같은 방재시설을 설치하고 있으나 우수유출저감시설은 대규모 예산이 소요되고 실제 침수지역에 피해 저감효과에 대한 효용성 문제에 대한 제기뿐만 아니라 과밀화된 도심지에서는 지하공간 활용에 한계가 있는 실정이므로 도심지의 다양한 공간을 활용한 도시 배수 및 저류시설에 대한 연구가 필요하다. 따라서 본 연구에서는 유휴 공간인 도로 측구부 공간을 활용하여 도로 노면수를 저류 및 지체할 수 있는 노면수 측구 저류시설의 개념을 제시하고 측구저류조의 활용성을 판단하기 위하여 빗물받이 유입구, 빗물받이, 측구 저류조 및 빗물받이와 측구저류조 연결부에서의 노면수 유입, 유출 및 저류 등의 다양한 흐름 변화를 확인하기 위하여 Fluent 모형의 적용성을 분석하였다. 수치모의 전체 형상은 50x50cm 크기의 빗물받이를 기준으로 양쪽에 2m 길이의 측구 저류조를 원형관으로 연결하여 1/5 축소모형으로 구성하고 격자는 빗물받이 유입부, 빗물받이 및 측구 저류조 내부의 복잡한 3차원 흐름을 모의하기 위해 사면체와 육면체로 조밀하게 생성하였다. 다상유동해석을 위해 VOF(Volume of Fluid)방법을 적용하였고, 수치해석 방법으로는 비정상류, 난류 모형으로는 SST k-ω모형을 적용하였다. 수치모의 조건으로는 설계빈도별(5~30년) 우수유출량을 산정하여 유입 유량별 기존 빗물받이 유입부에서의 유입흐름, 빗물받이 내부에서의 와 발생흐름, 측구 저류조 및 연결관에서의 흐름을 구현하여 분석하였다. 수치모의 결과 빗물받이 유입부에서 연결관을 통한 측구 저류조로 유입되는 유입흐름과 빗물받이 하단부의 배수관을 통해 유출되는 흐름을 정상적으로 구현하였으며, 빗물받이 유입부 및 측구 저류조 연결관에서의 유속변화도 확인할 수 있었다. 또한 빗물받이와 측구 저류조에서 다양한 흐름을 구현하기 위한 Flunet 모형의 적용성을 검토하였으며, 향후 수리실험을 통하여 실제 흐름과의 매개변수 최적화 및 다양한 도로 조건의 변화를 고려한 수치모의 분석을 통하여 지속적인 모형의 검증이 가능할 것으로 판단된다.

• 한국노년학
• /
• v.29 no.4
• /
• pp.1463-1478
• /
• 2009

The purpose of this study is to investigate the characteristics of the elderly based on the types of Kyungrodang participation and explores ways toward development of Kyungrodang. A national sample data, collected by the Korean Institute for the Health and Social Welfare in 2004 is analyzed by employing Chi-Square test of independence, ANOVA, and multiple logistic regression(n=3,005). A significant difference is noted in age, area, and socioeconomic status among the elderly based on the types of Kyungrodang participation. The results show that those elderly living in rural areas with older and lower socioeconomic status are more likely to participate at Kyungrodang, whereas, elderly living in urban areas with younger and higher socioeconomic status are less likely to participate at Kyungrodang and discontinue to use the services. Although there is a difference between the gender, the most significant reason for not using and discontinuing Kyungrodang is because the elderly can not get along with the other participants. In other words, the major problem that needs to be solved is to socializing and providing service programs satisfying all participants. Based on the results and recent socioeconomic changes of the older population, some policy issues are suggested for the development of Kyungrodang.

• Korean Journal of Remote Sensing
• /
• v.40 no.1
• /
• pp.71-80
• /
• 2024

In this study, a proposed ensemble learning technique aims to enhance the semantic segmentation performance of images captured by Unmanned Aerial Vehicles (UAVs). With the increasing use of UAVs in fields such as urban planning, there has been active development of techniques utilizing deep learning segmentation methods for land cover segmentation. The study suggests a method that utilizes prominent segmentation models, namely U-Net, DeepLabV3, and Fully Convolutional Network (FCN), to improve segmentation prediction performance. The proposed approach integrates training loss, validation accuracy, and class score of the three segmentation models to enhance overall prediction performance. The method was applied and evaluated on a land cover segmentation problem involving seven classes: buildings,roads, parking lots, fields, trees, empty spaces, and areas with unspecified labels, using images captured by UAVs. The performance of the ensemble model was evaluated by mean Intersection over Union (mIoU), and the results of comparing the proposed ensemble model with the three existing segmentation methods showed that mIoU performance was improved. Consequently, the study confirms that the proposed technique can enhance the performance of semantic segmentation models.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.11
• /
• pp.29-42
• /
• 2023

In this paper, we propose a method to enhance the prediction accuracy of solar irradiance for three major South Korean cities: Seoul, Busan, and Incheon. Our method entails the development of five generative models-vanilla GAN, CTGAN, Copula GAN, WGANGP, and TVAE-to generate independent variables that mimic the patterns of existing training data. To mitigate the bias in model training, we derive values for the dependent variables using random forests and deep neural networks, enriching the training datasets. These datasets are integrated with existing data to form comprehensive solar irradiance prediction models. The experimentation revealed that the augmented datasets led to significantly improved model performance compared to those trained solely on the original data. Specifically, CTGAN showed outstanding results due to its sophisticated mechanism for handling the intricacies of multivariate data relationships, ensuring that the generated data are diverse and closely aligned with the real-world variability of solar irradiance. The proposed method is expected to address the issue of data scarcity by augmenting the training data with high-quality synthetic data, thereby contributing to the operation of solar power systems for sustainable development.

• Korean Journal of Remote Sensing
• /
• v.39 no.6_3
• /
• pp.1721-1730
• /
• 2023

As awareness of the problem of global warming emerges around the world, the role of carbon sinks in settlement is increasingly emphasized to achieve carbon neutrality in urban areas. In order to manage carbon sinks in settlement, it is necessary to identify the current status of carbon sinks. Identifying the status of carbon sinks requires a lot of manpower and time and a corresponding budget. Therefore, in this study, a map predicting the location of trees was created using already established tree location information and Sentinel-2 satellite images targeting Seoul. To this end, after constructing a tree presence/absence dataset, structured data was generated using 16 types of vegetation indices information constructed from satellite images. After learning this by applying the Extreme Gradient Boosting (XGBoost) model, a tree prediction map was created. Afterward, the correlation between independent and dependent variables was investigated in model learning using the Shapely value of Shapley Additive exPlanations(SHAP). A comparative analysis was performed between maps produced for local parts of Seoul and sub-categorized land cover maps. In the case of the tree prediction model produced in this study, it was confirmed that even hard-to-detect street trees around the main street were predicted as trees.