• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.735-740
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• 2008

The Design manual for adjusting the capacity and LOS of facilities has been shared in urban railways and high-speed railway stations. However, the pattern of urban railways users and those of high-speed railway users are different from each other. For an example, the high-speed railway users tend to carry voluminous luggages and the transportation disadvantaged such as children and the elderlies. Accordingly, we see that the scale of facilities and the station itself should be constructed differently. The transfer facilities in the high-speed railway stations are classified widely into walking assisting facilities and convenient facilities. We invented the concept of PME (Pedestrian Moving Equivalent) and PWE (Pedestrian Waiting Equivalent)for the spatial calculation of those who are with wheeled luggages, back packs, and children to reflect the uniqueness of users in high-speed railway stations. These equivalents have been applied to the design of the facilities to asses the new Capacity and LOS that are users' favored.

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.22-35
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• 2016

In this study CALPUFF modeling was performed to establish a correlation between regions of frequent civil odor complaints near Gumi national industrial complex and odor-emission facilities of synthetic fiber manufacturers in the same area as main acetaldehyde-emission point sources. As a result of the CALPUFF modeling, the maximum concentration of acetaldehyde in Gumi national industrial complex was reduced from O ($10^{-5}g/m^3$) to O ($10^{-6}g/m^3$) upon improving emission facilities of T company so that the maximum concentrations of acetaldehyde frequently appeared in complex 3. In addition, the predicted range of the maximum acetaldehyde concentration in Gumi national industrial complex was also improved in comparison with that prior to improving emission facilities of T company. These maximum concentrations of acetaldehyde obtained to estimate the expected contribution of total acetaldehyde point source by CALPUFF modeling showed the similar values to those measured in 'HAPs investigation in the region of Gumi-Daegu' and were consistent to the trend of civil odor complaints. Therefore, the expected contribution of total acetaldehyde point source was validated. The relative contribution of T company upon improving its emission facilities was predicted to be lowered by more than factor of two, compared to that prior to improving its emission facilities. To the contrary, the relative contribution of W company upon improving emission facilities of T company was predicted to be increased by more than factor of two, compared to that prior to improving emission facilities of T company. This indicates that the contribution of aldehyde point sources of W company was relatively increased upon improving emission facilities of T company.

• Proceedings of the Korea Water Resources Association Conference
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• 1998.05a
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• pp.68-75
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• 1998

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.100-109
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• 2016

Low impact development (LID) facilities are established for the purpose of restoring the natural hydrologic cycle as well as the removal of pollutants from stormwater runoff. Improved efficiency of LID facilities can be obtained through the optimized interaction of their major components (i.e., plant, soil, filter media, microorganisms, etc.). Therefore, this study was performed to evaluate the performances of LID facilities in terms of runoff and pollutant reduction and also to provide an optimal maintenance method. The monitoring was conducted on four LID technologies (e.g., bioretention, small wetlands, rain garden and tree box filter). The optimal SA/CA (facility surface area / catchment area) ratio for runoff reduction greater than 40% is determined to be 1 - 5%. Since runoff reduction affects the pollutant removal efficiency in LID facilities, SA/CA ratio is derived as an important factor in designing LID facilities. The LID facilities that are found to be effective in reducing stormwater runoff are in the following order: rain garden > tree box filter > bioretention> small wetland. Meanwhile, in terms of removal of particulate matter (TSS), the effectiveness of the facilities are in the following order: rain garden > tree box filter > small wetland > bioretention; rain gardens > tree box filter > bioretention > small wetland were determined for the removal of organic matter (COD, TOC), nutrients (TN, TP) and heavy metals (Cu, Pb, Cd, Zn). These results can be used as an important material for the design of LID facilities in runoff volume and pollutant reduction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3741-3746
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• 2012

The safety accidents due to the insufficient visibility are frequently occurred at the coastal zone. Therefore, safety facilities that provide visibility are certainly required to prevent accidents. In order to solve this demand, the concept of the light emitting system embedded concrete (LESeCON) are established and then concrete curb is produced for application to the coastal zone. To investigate the mechanical and functional performance of concrete curb developed in this study, the bending strength test and the visibility test are conducted.

• Smart Structures and Systems
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• v.29 no.1
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• pp.153-166
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• 2022

Identifying fine cracks in steel bridge facilities is a challenging task of structural health monitoring (SHM). This study proposed an end-to-end crack image segmentation framework based on a one-step Convolutional Neural Network (CNN) for pixel-level object recognition with high accuracy. To particularly address the challenges arising from small object detection in complex background, efforts were made in loss function selection aiming at sample imbalance and module modification in order to improve the generalization ability on complicated images. Specifically, loss functions were compared among alternatives including the Binary Cross Entropy (BCE), Focal, Tversky and Dice loss, with the last three specialized for biased sample distribution. Structural modifications with dilated convolution, Spatial Pyramid Pooling (SPP) and Feature Pyramid Network (FPN) were also performed to form a new backbone termed CrackDet. Models of various loss functions and feature extraction modules were trained on crack images and tested on full-scale images collected on steel box girders. The CNN model incorporated the classic U-Net as its backbone, and Dice loss as its loss function achieved the highest mean Intersection-over-Union (mIoU) of 0.7571 on full-scale pictures. In contrast, the best performance on cropped crack images was achieved by integrating CrackDet with Dice loss at a mIoU of 0.7670.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.772-781
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• 2010

In this study, a revegetation reinforced earth retaining wall to strengthen the strength than construction and make up for the weakness; eco-friendly part, of the existing facilities is new construction method. The special attention is that Eco-Metal reinforced retaining wall is not use concret. Before test construction on the scene, the stability of Eco-Metal reinforced retaining wall was checked by an experiment with a model and numerical analysis. The result of an experiment with a model was that the loaded tensile stress 40.2KN/m was more than long-term design tensile strength 29.4KN/m at Geogrid and a safety factor of numerical analysis was 1.14.

• Journal of the Korea Construction Safety Engineering Association
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• s.47
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• pp.56-62
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• 2008

In order to apply the Limit Equilibrium Method generally used for the slope stability analysis to the vertical excavation walls reinforced by soil-nailing, in this study, the Limit Equilibrium Method for the temporary shoring facilities reinforced by soil-nailing was proposed, which is based on the stability for the horizontal displacement. In this study, the relation of the internal friction angles of the ground and the vertical excavation depths was arranged, which is satisfying the stability on the horizontal displacement by using the verification of the Limit Equilibrium Method. And then, the rational reinforcing length of soil-nailing was proposed for the critical areas. In addition, the modified safety ratio satisfying the stability on the horizontal displacement was proposed, when the Limit Equilibrium Method was applied to the vertical excavation walls reinforced by soil-nailing.

• Structural Engineering and Mechanics
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• v.78 no.1
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• pp.77-86
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• 2021

Local school buildings are critical facilities that can provide shelter in disasters such as earthquakes, so they must be more resistant to seismic forces than other structures. In this study, a sensitivity analysis was conducted to determine which columns-as the most critical members in a reinforced concrete building-most urgently require seismic retrofitting. The sensitivity analysis was conducted using an optimization technique with the location of each column as a parameter. A numerical model was developed to simulate a realistic collapse mode through a three-dimensional dynamic analysis. Based on numerical analysis results, it was found that the columns positioned in the lower floors, such as the first floor and in the outer part of a building, urgently require retrofitting. For reinforcement of the RC columns, which has been proven for its performance in previous research, was applied. Through this study, the importance of appropriate retrofitting is demonstrated. Further, a method for determining the appropriate location for retrofitting-when retrofitting is not possible on the entire structure-is presented.

• Proceedings of the KSRS Conference
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• v.1
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• pp.432-435
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• 2006

Potential application topics of KOMPSAT-3 image in the field of precision agriculture are suggested. The topics can be categorized as fundamental and applied ones that have contents of static and dynamic characteristics respectively. As fundamental topics, precision information of agriculture that is related to farmland and its crop attributes, precision information of rural infrastructure that is related to rural village and its facilities, precision information of stream environment that is related to rural water resources and its facilities, and precision information of eco-environment that is especially related to riparian ecology and environmental status are included. As applied topics, precision rural water resources that has thematic contents of continuous and event-based runoff, spatial and temporal soil moisture and evapotranspiration, precision agricultural watershed environment that has the contents of spatial and temporal soil loss, sediment and pollutants transport, and precision temporal and spatial crop growth that has the contents of temporal crop texture, spectral reflectance, leaf area index, spatial crop protein information.