• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.151-154
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• 2005

With the aim of global environmental monitoring we carried out GPR (Ground Penetrating Radar) surveys at the Livingstion Island in Antarctica. Research area is near the Mt. Charra (340m) in Livingston Island which is located 80 km to the southwest of the King Sejong Station. We have collected 5 lines of GPR data. Two kinds of survey, CMP (Common Midpoint) surveys and common offset profiles, were performed. We classified the glacier into the three layers using electromagnetic velocity of the ice and reflection characteristic, The depth of glacier reached about $80{\~}110\;m$. Some reflectors showed the evidence of the water filled englacial drainage and volcanic ash-layers.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.2
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• pp.139-149
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• 2014

A new technique, namely the combination of satellite and trajectory analysis (CSTA), for exploring the spatio-temporal distribution information of volcanic ash plume (VAP) from volcanic eruption. CSTA uses the satellite derived ash property data and a matching forward-trajectories, which can generate airmass history pattern for specific VAP. In detail, VAP properties such as ash mask, aerosol optical thickness at 11 ${\mu}m$ ($AOT_{11}$), ash layer height, and effective radius from the Moderate Resolution Imaging Spectro-radiometer (MODIS) satellite were retrieved, and used to estimate the possibility of the ash forecasting in local atmosphere near volcano. The use of CSTA for Iceland's Eyjafjallaj$\ddot{o}$kull volcano erupted in May 2010 reveals remarkable spatial coherence for some VAP source-transport pattern. The CSTA forecasted points of VAP are consistent with the area of MODIS retrieved VAP. The success rate of the 24 hour VAP forecast result was about 77.8% in this study. Finally, the use of CSTA could provide promising results for VAP monitoring and forecasting by satellite observation data and verification with long term measurement dataset.

• Journal of the Korean Geophysical Society
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• v.8 no.2
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• pp.63-66
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• 2005

With the aim of global environmental monitoring we carried out GPR (Ground Penetrating Radar) surveys at the Livingstion Island in Antarctica. Research area is near the Mt. Charra (340 m) in Livingston Island which is located 80 km to the southwest of the King Sejong Station. We have collected 5 lines of GPR data. Two kinds of survey, CMP (Common Midpoint) surveys and common offset profiles, were performed. We classified the glacier into the three layers using electromagnetic velocity of the ice and reflection characteristic. The depth of glacier reached about 80∼110 m. Some reflectors showed the evidence of the water filled englacial drainage and volcanic ash-layers.

• Journal of the Korean Geographical Society
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• v.33 no.3
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• pp.447-454
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• 1998

As a widespread tephra erupted 24 to 25 KA, Aira-Tn Ash, or AT, provides an invaluable datum for stratigraphic study of late Pleistocene in Northeast Asia. AT can be identified from their tonal characteristic and morphology (the so­called bubble-wail feature), as well as typical refractive index. First reported in 1983, its presence was confirmed from many palaeolithic deposits distributed throughout Korea. It forces us to reconsider the age of prominent Pleistocene deposits. At the famous archaeological site of Chon-gok-ni, presence of AT lends a firm support that sedimentation and deposition of lithic assemblage were in fact a late Upper Pleistocene event, thus, throwing a new question at archaeologists to explain why such archaic-looking tools were continued to be made. Discovery of AT at Chongdongjin is more surprising, since the coastal terrace has been regarded by many as an early Lower Pleistocene eustatic feature. It implies strongly that we need to devise a new scheme for Quaternary stratigraphy. In the absence of reliable datum and marker for Quaternary research, efforts must be given to search for and identify AT and other widespread tephras.

• The Journal of Engineering Geology
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• v.23 no.2
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• pp.149-160
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• 2013

Volcanic activity commonly creates a highly complicated volcanic complex due to the admixture of lava flow and sedimentation of volcanic ash. The Song-Gok site is composed of volcanic rocks that collapsed at the lower part of the slope, in combination with several discontinuities in and around a fault. The results of projection analysis indicated the possibility of plane, wedge, and toppling failure in the failure section. The results of discontinuity modeling using the Distinct Element Method (DEM) revealed a total displacement of 207 mm and a joint shear displacement of 114 mm. The yield surface zone was verified at the fault plane of the failure section. In geotechnical terms, volcanic rock slopes are characteristically vulnerable to failure because of differential weathering among the various rock types, the effect of groundwater based on the permeability of the rocks, and the presence of systematic joints generated by the cooling and contraction of lava. When considering the stability of a volcanic rock slope, it is necessary to consider data such as the geological features of the rock, as obtained through detailed geological survey, and variations in discontinuities and rock blocks.

• Korean Journal of Heritage: History & Science
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• v.55 no.2
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• pp.146-165
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• 2022

The purpose of this study is to identify differences in the formative characteristics and system of Jobok by comparing the three relics Ui, Sang, and Daedae, which comprised Jeon-Sik's Jobok, with the data in the literature and five excavated Jobok relics, Sin Kyung-yu, Kwon-Woo, Hwasan-Gun, Milchang-Gun, and Lee Ik-jeong, from the 17th and 18th centuries. Jeon-Sik'sJobok was designated as a Gyeongbuk tangible cultural heritage, Sangju JeonSik Jobok and Crafts, in 2021. The three components of Jeon-Sik's Jobok are valuable as historical data since they are the oldest relics confirming colors. Regrettably, the edging fabric of the Ui made of red twill was mostly lost, with only traces remaining. Based on records, it was presumed that the edging fabric was black. It was confirmed that white decorative lines were yet to be used. In Jeon Sik's Sang, only the three front widths and one rear width remain, but the shape of the four rear widths can be inferred, and the creases were held only at the waist. Eighteenth-century Sang was connected at intervals at the end of the waist. Seventeenth-century Sang was connected with a slight overlapping of the rear Sang below the front Sang; therefore, it is assumed that Jeon Sik's Sang was also connected by overlapping the rear by more or less than 5cm below the front. After Hwasan-gun, the Sang was first made using black lines, then white lines were inserted, and, finally, it was pleated from the waist to the hem. The Daedae made the Yo and the Sin by folding the corners to form a 冂 shape with a single long band. The white Ju(紬) and the green yumunsa were used for the Daedae and the edges. This matches the color of the Daedae seen in the Jobok portraits of Milchang-gun, Lee Ik-jeong, and Jeong Hwi-ryang from the 18th century. In the 17th century, the Daedae made the Yo and the Sin by folding a long band like the Daedae of Jeon-Sik. After the 18th century, the Yo and the Sin were made separately and connected. To tie the Daedae to the waist, thin straps were attached at both ends. The relics of Jeon-Sik can be evaluated as reflecting the 17th-century Jobok system in terms of color and shape. Furthermore, it can be said that they are important historical data complementing the insufficient or inaccurate records of the Gukjoolyeui-seolye and Gyeongguk-daejeon.

• Journal of Korean Society of Disaster and Security
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• v.5 no.2
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• pp.81-87
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• 2012

Critical infrastructures (energy, information technology and communications, banking, transportation, public government services, etc.) are now more vital to modern society. Citizens, businesses and governments all rely on an array of interlinked physical and information infrastructures to satisfy their needs and perform their daily operations. At the same time, these infrastructures are becoming increasingly interdependent, such that failure of one of them can often propagate and result in domino effects. Recent dramatic episodes, from 9/11 to the Madrid train bombings, the April 2010 ash cloud the power cuts in Korea in 2011, and the cyber-attacks have highlighted the need for a comprehensive, internationally coordinated policy for the protection of critical infrastructures. For the purposes of this report, we define critical infrastructure as infrastructure whose failure would result in substantial damage to society and/or the economy.

• Atmosphere
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• v.34 no.2
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• pp.217-231
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• 2024

The Korea Integrated Model (KIM)-based real-time volcanic ash dispersion prediction system, which employs the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, has been developed to quantitatively predict volcanic ash dispersion in East Asia and the Northwest Pacific airspace. This system, known as KIM-HYSPLIT, automatically generates forecasts for the vertical and horizontal spread of volcanic ash up to 72 hours. These forecasts are initiated upon the receipt of a Volcanic Ash Advisory (VAA) from the Tokyo Volcanic Ash Advisory Center by the server at the Korea Meteorological Administration (KMA). This system equips KMA forecasters with diverse volcanic ash prediction information, complemented by the Unified Model (UM)-based HYSPLIT (UM-HYSPLIT) system. Extensive experiments have been conducted using KIM-HYSPLIT across 128 different volcanic scenarios, along with qualitative comparisons with UM-HYSPLIT. The results indicate that the ash direction predictions from KIM-HYSPLIT are consistent with those from UM-HYSPLIT. However, there are slight differences in the horizontal extent and movement speed of the volcanic ash. Additionally, quantitative verifications of the KIM-HYSPLIT forecasts have been performed, including threat score evaluations, based on recent eruption cases. On average, the KIMHYSPLIT forecasts for 6 and 12 hours show better quantitative alignment with the VAA forecasts compared to UM-HYSPLIT. Nevertheless, both models tend to predict a broader horizontal spread of the ash cloud than indicated in the VAA forecasts, particularly noticeable in the 6-hour forecast period.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.2
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• pp.14-23
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• 1998

The present study investigates numerically particle laden flow through compressor cascade. In general, a lot of turbine engines are affected by various particles which are suspending in the atmosphere. Especially in the case of aircraft aviating in volcanic, industrial and desert region including many particles, each components of engine system are damaged severely. That damage modes are erosion of compressor binding and rotor path components, partial or total blockage of cooling passage and engine control system degradation.. Initial damages can not be serious but cumulation of damages influences on safety of aircraft control and economical maintenance cost of engine system can be increased. When dust, materials and volcanic particles in the atmosphere flow in the compressor, it is necessary to predict damaged and deposited region of compressor blades. To the various flow inlet angle, predictions of particles trajectory in compressor cascade by Lagrangian method are presented and impulses by impaction of particles at blade surface are calculated. By the definition of particle deposition efficiency, characteristics of particles impact are considered quantitatively. With these prediction and experimental data, erosion rates are predicted for two materials - ceramic, soft metal - on compressor blade surface. Improvements like coating of blade surface could be found, by above prediction.

• The Journal of Engineering Geology
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• v.10 no.2
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• pp.18-35
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• 2000

The most dominant type of landslide in Korea is debris flows which mostly take place along mountain slopes during the rainy season, July to August. The landslides have been reported to begin activation when rainfall is more than 200mm within 2days. The debris flows are usually followed by translational slips which occur upper part of mountain slopes and they transit to debris flow as getting down to the valleys. Lithology, location, slope inclination, grain size distribution of soil, permeability, dry density and porosity have been proved as triggering factor causing translational slides. The triggering data taken from mapping are statistically analysed to get landslide potential quantitatively. Rock mass creeps mostly occur on well bedded sedimentary rocks in Kyeongsang Basin. Although the displacement of rock mass creep is relatively small about 1m, the creep can cause severe hazards due to relatively large volume of the involved rock mass. Examples are rock mass creep occurred in the mouth of Hwangryongsan Tunnel, in Chilgok and in Sachon in 1999. Although the direct factor of the creeps are due to slope cutting at the foot area, more attention is required A rotational slide occurring within thick soil formation or weathered rock is also closely related to bottom part of slope cutting. It is propagated circular or semi-circular type. Especially in korea, the rotational slide may be frequently occurred in Tertiary tuff area. Because they are mainly composed of volcanic ash and pyroclastic materials, well developed joints and high degree of swelling and absorption can easily cause the slide. The landslide among the Pohang-Guryongpo national road is belong to this type of slide.