• Journal of Korean Society of Rural Planning
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• v.19 no.3
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• pp.51-59
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• 2013

The objective of this study was to make a map of farmland vulnerability to flood inundation based on morphologic characteristics from the flood-damaged areas. Vulnerability mapping based on the records of flood damages has been conducted in four successive steps; data preparation and preprocessing, identification of morphologic criteria, calculation of inundation vulnerability index using a fuzzy membership function, and evaluation of inundation vulnerability. At the first step, three primary digital data at 30-m resolution were produced as follows: digital elevation model, hill slopes map, and distance from water body map. Secondly zonal statistics were conducted from such three raster data to identify geomorphic features in common. Thirdly inundation vulnerability index was defined as the value of 0 to 1 by applying a fuzzy linear membership function to the accumulation of raster data reclassified as 1 for cells satisfying each geomorphic condition. Lastly inundation vulnerability was suggested to be divided into five stages by 0.25 interval i.e. extremely vulnerable, highly vulnerable, normally vulnerable, less vulnerable, and resilient. For a case study of the Jinju, farmlands of $138.6km^2$, about 18% of the whole area of Jinju, were classified as vulnerable to inundation, and about $6.6km^2$ of farmlands with elevation of below 19 m at sea water level, slope of below 3.5 degrees, and within 115 m distance from water body were exposed to extremely vulnerable to inundation. Comparatively Geumsan-myeon and Sabong-myeon were revealed as the most vulnerable to farmland inundation in the Jinju.

• Smart Media Journal
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• v.9 no.3
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• pp.46-51
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• 2020

Pine wilt disease is one of the reasons that results in huge damage on pine trees in east Asia including Korea, Japan, and China, and early finding and removing the diseased trees is an efficient way to prevent the forest from wide spreading. This paper proposes a searching method of the damaged pine trees from wilt disease in ortho-images corrected from RGB images, which are captured by unmanned aviation vehicles. The proposed method constructs patch-based classifier using ResNet18 backbone network, classifies the RGB ortho-image patches, and make the results as a heat map. The heat map can be used to find the distribution of diseased pine trees, to show the trend of spreading disease, and to extract the RGB distribution of the diseased areas in the image. The classifier in the work shows 94.7% of accuracy.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.5
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• pp.1-16
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• 2011

This study was intended to develop and suggest 'residents-driven and citizen-participatory restoration procedures' for degraded ecosystems in BaigDooDaeGahn. With some concerns of current engineering-focused restoration approach for damaged ecosystem, the proposed procedures were designed based on the analysis of several case studies on citizen participatory projects such as the Habitat Movement, the Taean tidal wetland restoration effort in Korea, and some historical and innovative cases in Japan and the United States. The suggested procedures were considered to be a dialectical spiral model which was consisted of two goal axis, six system elements, four developmental stages, and five restoration steps. The new system and procedures were applied to damaged farmland areas (about 0.3 ha) on the top of BaigDooDaeGahn, Kangneung city with participation of more than 100 local residents and a dozen of citizen from Seoul. Both high level of possibilities and some barriers for future extended application were identified and adopted for the final version of the proposed procedures for ecological restoration.

• Journal of Digital Convergence
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• v.14 no.3
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• pp.437-443
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• 2016

To treat a kind of nail damage, this study proceeded with gel polish procedure oriented to 19 women in their twenties and thirties, dividing into three experimental groups, such as the A group with non-treatment (n=6), the B group taking Nutritional Convergent supplement (n=6), and the C group simultaneously taking Nutritional Convergent supplement and Nail Convergent Strengthener (n=7), and inquired into the superficial change of nails, changes of thickness, analysis of damage degree and satisfaction rate. The analysis shows that the C group simultaneously applied with dietary supplement and complex nail supplement presented the best result in all areas. As for the morphological changes of the surface of nails measured by the scanning electron microscope, there were definite changes as compared with the B group. According to the result, it is proved that complex dietary supplement helps to improve the thickness and the surface of damaged nails and it is reasoned that a higher effect can be expected when complex nail supplement is simultaneously used.

• Journal of the Korean Geotechnical Society
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• v.37 no.12
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• pp.117-125
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• 2021

The occurrence of ground subsidence and sinkhole in downtown areas, which threatens the safety of citizens, has been frequently reported. Among the various mechanisms of a sinkhole, soil erosion through the damaged part of the sewer pipe was found to be the main cause in Seoul. In this study, a random forest model for predicting the occurrence of sinkholes caused by damaged sewer pipes based on sewage pipe information was trained using the information on the sewage pipe and the locations of the sinkhole occurrence case in Seoul. The random forest model showed excellent performance in the prediction of sinkhole occurrence after the optimization of its hyperparameters. In addition, it was confirmed that the sewage pipe length, elevation above sea level, slope, depth of landfill, and the risk of ground subsidence were affected in the order of sewage pipe information used as input variables. The results of this study are expected to be used as basic data for the preparation of a sinkhole susceptibility map and the establishment of an underground cavity exploration plan and a sewage pipe maintenance plan.

• Smart Structures and Systems
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• v.31 no.4
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• pp.393-407
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• 2023

To assess structural condition in a non-destructive manner, computer vision-based structural health monitoring (SHM) has become a focus. Compared to traditional contact-type sensors, the advantages of computer vision-based measurement systems include lower installation costs and broader measurement areas. In this study, we propose a novel computer vision-based vibration measurement and coarse-to-fine damage assessment method for truss bridges. First, a deep learning model FairMOT is introduced to track the regions of interest (ROIs) that include joints to enhance the automation performance compared with traditional target tracking algorithms. To calculate the displacement of the tracked ROIs accurately, a normalized cross-correlation method is adopted to fine-tune the offset, while the Harris corner matching is utilized to correct the vibration displacement errors caused by the non-parallel between the truss plane and the image plane. Then, based on the advantages of the stochastic damage locating vector (SDLV) and Bayesian inference-based stochastic model updating (BI-SMU), they are combined to achieve the coarse-to-fine localization of the truss bridge's damaged elements. Finally, the severity quantification of the damaged components is performed by the BI-SMU. The experiment results show that the proposed method can accurately recognize the vibration displacement and evaluate the structural damage.

• Journal of the Korean Geotechnical Society
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• v.22 no.11
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• pp.13-23
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• 2006

The sinkhole and leakage in dam core were detected at one of earth fill dams in Korea. The damage areas in the core of the dam were repaired by compaction grouting method. This study is to evaluate compaction grouting activity by in-situ and laboratory experiments before, during and after the remedial work. The intensive site investigation and geophysical survey were conducted during and after the compaction grouting work. The compaction grouting work was carried out for the damaged dam core between June 16 and August 24, 2000. The leakage reduction generally occurred in the core of the dam after the remedial work. The use of compaction grouting was considered the proper countermeasures for repairing the damaged dam. It shows that the loose or voided zones have been properly filled and the leakage has been reduced by about 96% of that before the treatment of the remedial work performed at dam core by compaction grouting.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.837-847
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• 2023

In this study, we explored a method for assessing the extent of damage caused by chemical substances at an accident site through the use of a vegetation index. Data collection involved the deployment of two different drone types, and the damaged area was determined using photogrammetry technology from the 3D point cloud data. To create a vegetation index image, we utilized spectral band data from a multi-spectral sensor to generate an orthoimage. Subsequently, we conducted statistical analyses of the accident site with respect to the damaged area using a predefined threshold value. The Kappa values for the vegetation index, based on the near-infrared band and the green band, were found to be 0.79 and 0.76, respectively. These results suggest that the vegetation index-based approach for analyzing damage areas can be effectively applied in investigations of chemical accidents.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.555-567
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• 2023

This study was conducted to compare the level of vegetation recovery based on the forest restoration techniques (natural restoration and artificial restoration) determined using the satellite imagery that targeted forest fire damaged areas in Goseong-gun, Gangwon-do. The study site included the area affected by the Goseong forest fire (1996) and the East Coast forest fire (2000). We conducted a time-series analysis of satellite imagery on the natural restoration sites (19 sites) and artificial restoration sites (12 sites) that were created after the forest fire in 1996. In the analysis of satellite imagery, the difference normalized burn ratio (dNBR) and normalized difference vegetation index (NDVI) were calculated to compare the level of vegetation recovery between the two groups. We discovered that vegetation was restored at all of the study sites (31 locations). The satellite image-based analysis showed that the artificial restoration sites were relatively better than the natural restoration sites, but there was no statistically significant difference between the two groups (p > 0.05). Therefore, it is necessary to select a restoration technique that can achieve the goal of forest restoration, taking the topography and environment of the target site into account. We also believe that in the future, accurate diagnosis and analysis of the vegetation will be necessary through a field survey of the forest fire-damaged sites.

• Korean Journal of Environment and Ecology
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• v.19 no.4
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• pp.385-392
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• 2005

This study was conducted in order to analysis the forest fire effect to the raptors habitating in and around the large forest fire occurred area, Goseong country, Gangwon province, Korea. There were observed raptor birds belonging to 8 species, 3 families, and 2 orders in the survey area. The most dominant species was Eurasian Hobby(Falco subbuteo), which was followed by Common Buzzard(Buteo buteo), Kestrel(Faico tinnunculus) and Chinese Sparrow Hawk(Accipiter soloensis). The largest number of species and individuals were observed in May 2002. In partially undamaged areas and undamaged areas, five species of rapacious birds were observed, which was the largest number of species observed. If an environment where rapacious birds can build nests is created in forest fire damaged area in order to raise the number of species and population, the number of species and population of rapacious birds living in the forest fire damaged area will grow further.