• Journal of Climate Change Research
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• v.5 no.4
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• pp.323-329
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• 2014

Since the terrain of Korea is complex, micro- as well as meso-climate variability is extreme by locations in Korea. In particular, air temperature of agricultural fields is influenced by topographic features of the surroundings making accurate interpolation of regional meteorological data from point-measured data. This study was carried out to compare spatial interpolation methods to estimate air temperature in agricultural fields surrounded by rugged terrains in South Korea. Four spatial interpolation methods including Inverse Distance Weighting (IDW), Spline, Ordinary Kriging (with the temperature lapse rate) and Cokriging were tested to estimate monthly air temperature of unobserved stations. Monthly measured data sets (minimum and maximum air temperature) from 588 automatic weather system(AWS) locations in South Korea were used to generate the gridded air temperature surface. As the result, temperature lapse rate improved accuracy of all of interpolation methods, especially, spline showed the lowest RMSE of spatial interpolation methods in both maximum and minimum air temperature estimation.

• Wind and Structures
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• v.37 no.2
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• pp.95-104
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• 2023

The latest revision of AS/NZS 1170.2 incorporates some new research and knowledge on strong winds, climate change, and shape factors for new structures of interest such as solar panels. Unlike most other jurisdictions, Australia and New Zealand covers a vast area of land, a latitude range from 11° to 47°S climatic zones from tropical to cold temperate, and virtually every type of extreme wind event. The latter includes gales from synoptic-scale depressions, severe convectively-driven downdrafts from thunderstorms, tropical cyclones, downslope winds, and tornadoes. All except tornadoes are now covered within AS/NZS 1170.2. The paper describes the main features of the 2021 edition with emphasis on the new content, including the changes in the regional boundaries, regional wind speeds, terrain-height, topographic and direction multipliers. A new 'climate change multiplier' has been included, and the gust and turbulence profiles for over-water winds have been revised. Amongst the changes to the provisions for shape factors, values are provided for ground-mounted solar panels, and new data are provided for curved roofs. New methods have been given for dynamic response factors for poles and masts, and advice given for acceleration calculations for high-rise buildings and other dynamically wind-sensitive structures.

• Journal of The Geomorphological Association of Korea
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• v.26 no.1
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• pp.1-14
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• 2019

Large landslide is a type of mass movement that causes drastic landform changesin a short period, and it causes huge human and property damage over a large area. The purpose of this study is to categorize the types and characteristics of large landslides around the Kokomeren River basin, Kyrgyzstan and to discuss the geomorphic development after the large landslides. The topographic analysis about a total of 20 landslides documented collapsed volumes of 0.01 to 1.10 km³, height drops of 180 to 1,770 m, and runout distances of 1,200 to 5,400 m. Rock avalanche and rockslide are identified as major types of large-scale landslides in the study area. Rock avalanches can be divided into P-type, J-type, and S-type based on the features of slope failure and kinematic characteristics of rock debris. Landslide synchronistic landforms such as trimlines, transverse ridges, longitudinal ridges, levees, and hummocks are well developed in the rock avalanche. The pieces of evidence of landslide dam, landslide-dammed lake, and remnant outburst flood deposits are observed in the upstream and downstream where the rockslides occurred. The Ak-Kiol landslide dam is the best example of a geomorphic development due to lake spillover and the large landslides were likely to be triggered by huge paleo-seismic events.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.1
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• pp.1-9
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• 2014

The purpose of this study was to identify the landscape characteristics of Youngnam-Lu by performing text analysis of related Korean poems over 600 years. A total of 354 poems were quantitatively analyzed for keywords and terms in particular categories such as nature. As a subsidiary analysis, topographic map was examined using CAD along with analysis of antique maps. Of the 354 poems reviewed, keywords frequently used are: 'Scenic sites'- 56 times, 'Long river' (長江) and 'Long stretched forest'(長林) - 39 times each, 'Superb scenery'- 31 times, 'Large field scenery'- 19 times, and 'Thousand-layered mountain view' - 14 times. In total, these keywords occurred 159 times in 44.9 % of these poems.1) The words used frequently in these poems, especially for those fall under category of nature, can be scored into different subcategories such as natural phenomena and geographical features. Occurrences of terms in each subcategory were main criteria for the analysis and the following is a list of subcategories with frequency in descending order: Natural phenomena (44%), geographical features (33%), plants (14%), and animals (9%). Among natural phenomena, phenomena related to sky were most frequent, 41 times, which might be due to superb sky view from Youngnam-Lu. Also geographical features of Youngnam-Lu were reflected in these poems, and the most prominent features were 'flow of the river' and 'Sand island' located in the Milyang River. These poems contained fairly large number of terms related to musical instruments (8%) which suggest that Young-Nam-Lu as a place where various musical instruments performances were held.

• The Journal of the Petrological Society of Korea
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• v.18 no.3
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• pp.211-221
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• 2009

This study illustrates the relationship between the petrographic characteristics of micrographic granite and the topographic features around Ijin-ri. Light-brown to light- gray granite is composed of intergrown fine-grained quartz + orthoclase, displaying micrographic textures. Miarolitic cavities are abundant. Many micro-landforms including tor, tafoni, and gnamma occurred in the micrographic granite of the study area. Tafoni is dominant in the north and gnamma is dominant in south. From our study of the occurrence and textural properties, two alteration zones were clearly identified; one is an external zone (A) characterized by abundant of small sized miarolitic cavities and the other is an internal zone (B) having them less than zone A. The former is dominant in north, and the latter is dominant in south. Particular geomorphologic features such as fluting cores and raised rims are present in the Ijin-ri area. This suggests that development of miarolitic cavities played an important role in the formation of the various geomorphologic features. Consequently, the petrogenesis of the micrographic granite is related to geomorphologic features in the external zone typified by abundant tafoni such as the tiger rock, and the formation of a platform as micro-landforms is influenced by thetextural differences of host rock in the internal zone.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.511-521
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• 2022

Cloud detection and removal from satellite images is an essential process for topographic observation and analysis. Threshold-based cloud detection techniques show stable performance because they detect using the physical characteristics of clouds, but they have the disadvantage of requiring all channels' images and long computational time. Cloud detection techniques using deep learning, which have been studied recently, show short computational time and excellent performance even using only four or less channel (RGB, NIR) images. In this paper, we confirm the performance dependence of the deep learning network according to the heterogeneous learning dataset with different resolutions. The DeepLabV3+ network was improved so that channel features of cloud detection were extracted and learned with two published heterogeneous datasets and mixed data respectively. As a result of the experiment, clouds' Jaccard index was low in a network that learned with different kind of images from test images. However, clouds' Jaccard index was high in a network learned with mixed data that added some of the same kind of test data. Clouds are not structured in a shape, so reflecting channel features in learning is more effective in cloud detection than spatial features. It is necessary to learn channel features of each satellite sensors for cloud detection. Therefore, cloud detection of heterogeneous sensors with different resolutions is very dependent on the learning dataset.

• Korean Journal of Remote Sensing
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• v.36 no.5_4
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• pp.1209-1220
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• 2020

In the case of forest areas, the installation of ground control points (GCPs) and the selection of terrain features, which are one of the unmanned aerial photogrammetry work process, are limited compared to urban areas, and safety problems arise due to non-visible flight due to high forest. To compensate for this problem, the drone equipped with a real time kinematic (RTK) sensor that corrects the position of the drone in real time, and a 3D flight method that fly based on terrain information are being developed. This study suggests to present a method for investigating damage using drones in forest areas. Position accuracy evaluation was performed for three methods: 1) drone mapping through GCP measurement (normal mapping), 2) drone mapping based on topographic data (3D flight mapping), 3) drone mapping using RTK drone (RTK mapping), and all showed an accuracy within 2 cm in the horizontal and within 13 cm in the vertical position. After evaluating the position accuracy, the volume of the landslide area was calculated and the volume values were compared, and all showed similar values. Through this study, the possibility of utilizing 3D flight mapping and RTK mapping in forest areas was confirmed. In the future, it is expected that more effective damage investigations can be conducted if the three methods are appropriately used according to the conditions of area of the disaster.

• Journal of the Korean Geographical Society
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• v.43 no.1
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• pp.87-103
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• 2008

The geographical name is an expression of human knowledge about living conditions and a basic tool for understanding about regional cultures and history as a result of spatiotemporal changes. This study aims to understand the historical and regional characteristics by analyzing the frequency and distribution of geographical names of 1:50,000 topographic map in the early 20th century and materializing on electronic cultural atlas. The result of this analysis is as follows. First, the aspect of distributed geographical names on the Korean Peninsula reflects a general trait of the country's natural and human environment included geographical features, population, arable land, the number of counties and villages, and functions of administration and military, etc. Second, through the frequency and weight of their names, the analysis shows not only the change of native names, but also the country's phase of the time by Japanese colonial policies such as exploitation of resources, the construction of railroads, and a desire to control of the border area with Manchuria. In addition, the study identified regional characteristics and differences in environmental perception and preferences, and naming basis and forms by the comparative analysis of each type of geographical names associated with village and ridge such as 'Chi' 'Ryung' 'Duk' 'Hang' 'Pyeong' 'Gok'. In particular, those characteristics were largely affected from environmental difference of each area.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.1
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• pp.15-25
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• 2022

This study was conducted to provide useful basic data for restoration and maintenance of the Changdeokgung Palace(昌德宮)'s inner palace area in the future by exploring the background of terraced flower beds installed in the front space of Seunghwaru(承華樓) and grasping the reality before and after terraced flower beds were installed. The main results of this study can be summarized as follows. First, in the early 1900s, the front space of Seunghwaru formed a relatively higher terrain than the Nakseonjae(樂善齋) area. In addition, along the topography of high north and low south, a yard surrounded by Haenggak(行閣) and a rectangular open space connected to the West Haenggak of Nakseonjae were created. In particular, the rectangular open space was a staircase-type slope in which rectangular stone columns were arranged at regular intervals. Second, the terraced flower beds of Seunghwaru originated from the renovation of the new building of Nakseonjae West Hanggak, which was implemented in the late 1920s. This is because in order to secure enough available land for construction and auxiliary space during the renovation of the new building, the terraced flower beds for topographic treatment was created along the cutting area after cutting off the original topography of the front space of Seunghwaru. Third, after the construction of the terraced flower beds, many deformation occurred in the topographic features of the front space of Seunghwaru. The front yard of Seunghwaru was relatively higher than the Nakseonjae area, but most of them were cut off and disappeared as the terraced flower beds were created. The staircase-type also disappeared after the construction of the new building and terraced flower beds. The stylobate and front fence of Seunghwaru were newly built along the alignment of terraced flower beds and the unique style of narrow gate and auxiliary stairs were also relocated to the new fence.

• Restorative Dentistry and Endodontics
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• v.38 no.1
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• pp.21-25
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• 2013

Objectives: The aim of this study was to evaluate the shaping ability of newly marketed single-file instruments, Wave One (Dentsply-Maillefer) and Reciproc (VDW GmbH), in terms of maintaining the original root canal configuration and curvature, with or without a glide-path. Materials and Methods: According to the instruments used, the blocks were divided into 4 groups (n = 10): Group 1, no glide-path / Wave One; Group 2, no glide-path / Reciproc; Group 3, #15 K-file / Wave One; Group 4, #15 K-file / Reciproc. Pre- and post-instrumented images were scanned and the canal deviation was assessed. The cyclic fatigue stress was loaded to examine the cross-sectional shape of the fractured surface. The broken fragments were evaluated under the scanning electron microscope (SEM) for topographic features of the cross-section. Statistically analysis of the data was performed using one-way analysis of variance followed by Tukey's test (${\alpha}$ = 0.05). Results: The ability of instruments to remain centered in prepared canals at 1 and 2 mm levels was significantly lower in Group 1 (p < 0.05). The centering ratio at 3, 5, and 7 mm level were not significantly different. Conclusions: The Wave One file should be used following establishment of a glide-path larger than #15.