• Korean Journal of Ecology and Environment
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• v.48 no.3
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• pp.188-194
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• 2015

River channel dredging and riparian development have been influenced morphology and quantity of natural river habitat. We compared distribution of riverside land and alluvial island in the Nakdong River with field survey and remote sensing analysis after the 4 Large River Project in South Korea. We digitized geomorphological elements, includes main channel, riverside land, and alluvial island by using georeferenced aerial photos taken in pre-dredging (2008) and post-dredging (2012) periods. Field survey was followed in 2012 for a ground truth of digitized boundaries and identification of newly constructed wetland types such as pond, channel, branch, and riverine type. We found that during the dredging period, riverside land and alluvial island were lost by 20.2% and 72.7%, respectively. Modification rate of riverside land was higher in the section of river kilometer 50~90, 140~180, and 210~270. Alluvial island had higher change rate in the section of river kilometer 50~70, 190~210, and 270~310. Average change rate for the riverside land and alluvial island was $-1.02{\pm}0.14km^2{\cdot}10km^{-1}$ and $-0.05{\pm}0.05km^2{\cdot}10km^{-1}$, respectively. Channel shaped wetlands (72.5%) constituted large portion of newly constructed wetlands.

• Ecology and Resilient Infrastructure
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• v.8 no.4
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• pp.266-272
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• 2021

Water friendly space refers to a place designated to plan and manage spaces for residents Water friendly activities. Efficient management of river Water friendly parks requires automated GIS data and DB construction of the water friendly facilities. Object-based classification using drone images or aerial images is attracting attention as an efficient means to acquire 3D spatial information in the country. To remove the miscellaneous image included in the extracted outline, a linear simplification of the outline is required, and it is difficult to apply manually, so various automation methods have been developed to overcome this, and among them, the most widely studied and utilized is the linear simplification method. In this study, the suitability of linear simplification algorithms such as Douglas-Peucker, Visvalingam-Whyatt, and Bend-simplify algorithms for the geometric shape of hydrophilic facilities was determined.

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.733-745
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• 2021

Although waxy corn varieties developed after the 1980s show differences depending on development stages and conditions, studies on the characteristics of waxy corn during the growth stage are rare. The subject of this study was a field survey and unmanned aerial vehicle (UAV) image acquisition of four waxy corn varieties cultivated in Idam-ri, Gammul-myeon, Goesan-gun, Korea. The study was conducted in four stages at intervals of two weeks after planting in 2019. The growth characteristics of each of the four varieties were analyzed using growth curves obtained based on field survey and UAV imagery data. The characteristics of each growth stage of the four varieties of corn, as assessed using normalized difference vegetation index (NDVI) and plant height (P.H.) values, were as follows. The growth model was identified as a model in which three-parameter logistic (3PL) curves reflect the growth characteristics of corn well. In particular, it was found that the variations in growth rate shown by P.H. and NDVI values clearly explain the differences between corn varieties. Among the four cultivars, growth and development first occurred at the early vegetative stage in Daehakchal, followed by Mibaek 2, Miheukchal, and finally Hwanggeummatchal. The variationsin P.H. and NDVI were achieved quickly and earlier in Daehakchal, followed by Mibaek 2, Hwanggeummatchal, and Miheukchal. It was confirmed that these results reflected the characteristics of the fast white-type varieties, while the black-type varieties were delayed, as in a previous study. These results reflect the resistance to lodging that affects the cultivation environment and the response characteristics to nutrients and moisture. It was confirmed that UAV accurately provides growth information that is very useful for analyzing the growth characteristics of each corn variety.

• Journal of the Korean Institute of Rural Architecture
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• v.13 no.1
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• pp.1-8
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• 2011

This aim of the study is to investigate the plan and elevation types of existing way stations built in the early 20th century Korea, focused on Choong-ang, Donghae-nambu, and Kyung-jeon line of the railroad tracklines. The plans and elevations are drawn up and analyzed based on literature data and aerial photographs through the survey. These way stations are classified into various types by room layout and front elevation. The basic plan types are composed of waiting room, station service room, and administration. The station service room has a train operation room in the projecting part of corner. This room has windows on every side to see in and out of train. There are the enlarged, extended waiting room types, and linear types in the other plan types. The waiting room is lied on the right side, and has a gable roof in elevation. The elevation types are classified with side and centralized, and so on by the placement and shape of gable roofs. The basic elevation types have gable roofs in sides lied on the waiting room, and these types are transformed into centralized types by extension of waiting room The others are the linear types without gable roofs and the unusual roof types in appearance.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.1
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• pp.51-56
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• 2003

The urban stream include the channel and its adjacent banks, or hillslopes and it consists of various landscape elements. The riparian ecosystem is important to people. Its water is extracted for irrigation and drinking supplies. Biodiversity and many wetland species are protected here. The riparian ecosystem is diverse and needs to be preserved well. So, it is necessary to measure the features of the urban stream accurately to figure out the change of the riparian ecosystem. However, the traditional Electronic Distance Measurement(EDM) surveying is difficult to measure the curvilinear features of the stream - e, g, angle, curve. The beacon Differential Global Positioning System(DGPS) can handle to measure the curvilinear shape. Therefore, the purpose of this study is to measure the change of the river bed in urban stream accurately using realtime beacon DGPS, and ultimately to provide the basic data for identifying the change of the river ecosystem.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.4
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• pp.231-240
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• 2017

This paper aims to study a method to estimate precise carbon absorption by quantification of forest information that uses accurate LiDAR data, hyperspectral image. To estimate precise carbon absorption value by using spatial data, a problem was found out of carbon absorption value estimation method with statistical method, which is already existed method, and then offered optimized carbon absorption estimation method with spatial information by analyzing with methods of compare digital aerial photogrammetry and LiDAR data. It turned out possible Precise classification and quantification in case of using LiDAR and hyperspectral image. Various classification of tree species was possible with use of LiDAR and hyperspectral image. Classification of hyperspectral image was matched in general with field survey and Mahalanobis distance classification method. Precise forest resources could be extracted using high density LiDAR data. Compared with existing method, 19.7% in forest area, 19.2% in total carbon absorption, 0.9% in absorption per unit area of difference created, and improvement was found out to be estimated precisely in international code.

• Journal of Korea Multimedia Society
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• v.23 no.8
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• pp.1075-1087
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• 2020

Aviation ICT technology is a convergence technology between aviation and electronics, and has a wide variety of applications, including navigation and education. Among them, in the field of aerial pilot training, there are many problems such as the possibility of accidents during training and the lack of coping skills for various situations. This raises the need for a simulated pilot training system similar to actual training. In this paper, pilot training data were collected in pilot training system using VR/AR to increase immersion in flight training, and Customized Pilot Training Platform with Collaborative Deep Learning in VR/AR Environment that can recommend effective training courses to pilots is proposed. To verify the accuracy of the recommendation, the performance of the proposed collaborative deep learning algorithm with the existing recommendation algorithm was evaluated, and the flight test score was measured based on the pilot's training data base, and the deviations of each result were compared. The proposed service platform can expect more reliable recommendation results than previous studies, and the user survey for verification showed high satisfaction.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.256-272
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• 2002

The purpose of this study is to develop landslide susceptibility analysis techniques using artificial neural network and to apply the newly developed techniques to the study area of Boun in Korea. Landslide locations were identified in the study area from interpretation of aerial photographs, field survey data, and a spatial database of the topography, soil type, timber cover, geology and land use. The landslide-related factors (slope, aspect, curvature, topographic type, soil texture, soil material, soil drainage, soil effective thickness, timber type, timber age, and timber diameter, timber density, geology and land use) were extracted from the spatial database. Using those factors, landslide susceptibility was analyzed by artificial neural network methods. For this, the weights of each factor were determinated in 3 cases by the backpropagation method, which is a type of artificial neural network method. Then the landslide susceptibility indexes were calculated and the susceptibility maps were made with a GIS program. The results of the landslide susceptibility maps were verified and compared using landslide location data. A GIS was used to efficiently analyze the vast amount of data, and an artificial neural network was turned out be an effective tool to maintain precision and accuracy.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.8
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• pp.861-866
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• 2015

This study was aimed to detect area of Submaine Groundwater Discharged(: SGD) around Jeju island using by remote sensing. Sea Surface Temperature(SST) was identified using IR camera on Unmaned Aerial Vehicle(UAV) at Gimnyeong port in study area. Then SGD location was detected by comparing range of SGD temperature. Generally, range of SGD temperature is distributed 15 to 17 like underground water. The result, SGD location was detected by SST distribution of Gimnyeong port recorded by IR camera in the southwest of study area.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.656-660
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• 2004

The Mobile Mapping System is an effective method to acquire the position and image data using vehicle equipped with the GPS (Global Positioning System), IMU (Inertial Measurement Unit), and CCD camera. It is used in various fields of road facility management, map update, and etc. In the general photogrammetry such as aerial photogrammetry, GCP (Ground Control Point)s are needed to compute the image exterior orientation elements (the position and attitude of camera). These points are measured by field survey at the time of data acquisition. But it costs much time and money. Moreover, it is not possible to make sufficient GCP as much as we want. However Mobile Mapping System is more efficient both in time and money because it can obtain the position and attitude of camera at the time of photographing. That is, Indirect Georeferencing must use GCP to compute the image exterior orientation elements, but on the other hand Direct Georeferencing can directly compute the image exterior orientation elements by GPS/INS. In this paper, we analyze about the positional accuracy comparison of ground point using the Direct Georeferencing and Indirect Georeferencing.