• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.1
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• pp.35-43
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• 2000

The slope gradient of the Korean Peninsula was analyzed by using DEM(DTED level 1). The Peninsula has high percentages of gentle slopes. But low plains and very steep slope regions are scarcely distributed in the Peninsula. Altitude lower than 150m areas are composed of plains and undulated plains. The steepest and most rugged topographies are observed in the range of altitude from 500m to 1,000m areas. The areas of altitude greater than 1,000m show plateau landscapes. By overlapping digital geology maps and the gradient grade maps, We revealed the characteristics of slope regions by geological districts. High latitude with steep slope are well developed in the geological districts of granitic gneiss(ARgr) and gneiss($PR_1$) of the Pre-Cambrian, sandstone of the Paleozoic era(P-T), and sedimentary rocks of the Mesozoic era($J_2$). Low altitude with gentle slope areas are representative in the districts of granite of the Mesozoic era($Jgr_1$), the Cretaceous sedimentary rocks of the Mesozoic era($K_1$, $K_2$) and the Cenozoic strata(N). Basalt extruded the Quaternary($Q_1$) are observed in the areas of very gentle slope but greater than 1,000m altitude.

• International Commerce and Information Review
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• v.14 no.2
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• pp.349-367
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• 2012

Recently, the global paradigm on the economic structure has been changed from the price-oriented borderless competition toward the sustainable quality movement due to the ever-increasing global warming and environmental issues. Since Korea hosted the global 20 summit in 2010, it has promoted the green growth policies and asked for the other countries to participate in. Unfortunately, it is not easy to figure out the green growth or green productivity because the economic performance has a side effect of environmental pollution such as CO2 emission. This paper aims to analyzes the methodological comparison for all the related issues with green productivity and suggests the new paradigm of global Malmquist-Lundberger index (GML) as the most flexible field and performance-oriented criteria to measure the green productivity.

• Journal of the Korean Institute of Gas
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• v.19 no.4
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• pp.62-67
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• 2015

In this paper, the consequence analysis has been evaluated for the damage effects of the LPG storage tanks when they are installed on the ground or underground. They should be performed to identify measures to reduce risks for the LPG storage tanks which are more widely used. In order to conduct a damage effect evaluation of the LPG storage tanks installed underground, FDS was used to simulate the LPG storage tanks installed and housed within a facility. The maximum pressure of the storage facilities for the LPG storage tanks has been calculated from the FDS, and it's results are used as an input variable for Phast which is a commercial software for evaluating the damage effects. Getting results from the consequence analysis and computational simulations(diffusion range of LFL and UFL, jet fire or explosions) were quantitatively presented for the damage effects.

• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.80-84
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• 2010

Satellite structure should be designed to accommodate and support safely the payload and equipments necessary for its own missions and to secure satellite and payloads from severe laucnch enviroments. The lauch environments imposed on satellites are quasi-static accelerations, aerodynamic loads, acoustic loads and shock loads. To qualify the structure design against low-frequency dyanmic enviromnent, sine vibration test should be performed. During sine vibration test, the notchings are implemented in order to keep the payloads and equipments from excessive loading at their own main modes. This paper deals with sine test prediction, sine vibration test results, comparison of predicted values and tested values, and verification of Finite Element Model.

• Economic and Environmental Geology
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• v.45 no.2
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• pp.145-156
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• 2012

Seafloor hydrothermal system occurs along the volcanic mid-ocean ridge, back-arc spreading center, and other submarine volcanic regions. The hydrothermal system is one of the fundamental processes controlling the transfer of energy and matter between crust/mantle and ocean; it forms hydrothermal vents where various deepsea biological communities are inhabited and precipitates metal sulfide deposits. Hydrothermal systems at convergence plate boundaries show diverse geochemical properties due to recycle of subducted material compared to simple systems at mid-ocean ridges. Sulfur isotopes can be used to evaluate such diversity in generation and evolution of hydrothermal system. In this paper, we review the sulfur isotope composition and geochemistry of hydrothermal precipitates sampled from several hydrothermal vents in the divergent plate boundaries in the western Pacific region. Both sulfide and sulfate minerals of the hydrothermal vents in the arc and backarc tectonic settings commonly show low sulfur isotope compositions, which can be attributed to input of magmatic $SO_2$ gas. Diversity in geochemistry of hydrothermal system suggests an active role of magma in the formation of seafloor hydrothermal system.

• The Journal of the Petrological Society of Korea
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• v.11 no.3_4
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• pp.214-233
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• 2002

Igneous rocks of Mt. Mudeung area are composed of Pre-Cambrian granite gneiss, Triassic hornblende-biotite granodiorite, Jurassic quartz diorite and Cretaceous igneous rocks. The Cretaceous igneous rocks consist of volcanic rocks (Hwasun andesite, Mudeung-san dacite and Dogok rhyolite) and granitic rocks (micrograpic granite and quartz porphyry). Major elements of the Cretaceous igneous rocks represent calc-alkaline rock series and correspond to a series of differentiated products from cogenetic magma. Igneous activity of Mt. Mudeung area started from volcanic activity, and continued to intrusive activity at end of the Cretaceous. In chondrite normalized REE pattern, most of igneous rocks of Mt. Mudeung area show similar pattern of Eu (-) anomaly. This is a characteristic feature of granite in continental margin by tectonic movement. Variation diagrams of total REE vs. La/Yb V vs. SiO$_2$ indicate differentiation and magnetite fractionation sequential trend of Hwasun andesite longrightarrowMudeungsan dacitelongrightarrowquartz porphyry. In mineral composition of these igneous rocks in mt. Mudeung area, composition of plagioclase and biotite coincidence with variation of whole rock composition, and emplacement and consolidation of magma is about 15 km (about 4.9 Kbar) in Jurassic quartz diorite and 2.0~3.2 km (0.6~1.0 Kbar) in Triassic hornblende-biotite granodiorite used by amphibolite geobarometer. Parental magma type of these granitic rocks of nt. Mudeung area corresponds to VAG field in Pearce diagram, and I-type in ACF diagram.

• Geophysics and Geophysical Exploration
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• v.6 no.1
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• pp.40-52
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• 2003

Despite the various opening models of the southwestern part of the East Sea (Japan Sea) between the Korean Peninsula and the Japan Arc, the continental margin of the Korean Peninsula remains unknown in crustal structure. As a result, continental rifting and subsequent seafloor spreading processes to explain the opening of the East Sea have not been adequately addressed. We investigated crustal and sedimentary velocity structures across the Korean margin into the adjacent Ulleung Basin from multichannel seismic reflection and ocean bottom seismometer data. The Ulleung Basin shows crustal velocity structure typical of oceanic although its crustal thickness of about 10 km is greater than normal. The continental margin documents rapid transition from continental to oceanic crust, exhibiting a remarkable decrease in crustal thickness accompanied by shallowing of Moho over a distance of about 50 km. The crustal model of the margin is characterized by a high-velocity (up to 7.4 km/s) lower crustal (HVLC) layer that is thicker than 10 km under the slope base and pinches out seawards. The HVLC layer is interpreted as magmatic underplating emplaced during continental rifting In response to high upper mantle temperature. The acoustic basement of the slope base shows an igneous stratigraphy developed by massive volcanic eruption. These features suggest that the evolution of the Korean margin can be explained by the processes occurring at volcanic rifted margins. Global earthquake tomography supports our interpretation by defining the abnormally hot upper mantle across the Korean margin and in the Ulleung Basin.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.397-411
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• 2020

The Cretaceous Yucheon Group is volcano-sedimentary successions that are formed by volcanic activities of the Gyeongsang Volcanic Arc. Lack of the detailed field researches on the Yucheon Group results in poor understanding of the formation time and the tempo-spatial development of the volcanic arc. Also, this causes difficulties to reconstruct the depositional history from the Sindong and Hayang groups to the Yucheon Group. In this study, we conducted field research targeting to the interface between topmost part of the Hayang Group and the lowermost part of the Yucheon Group from Hyeonpoong to Bugok areas. We also identified depositional timing of the lowermost part of the Yucheon Group using SHRIMP U-Pb zircon age dating. This Yucheon Group is composed of tuff and lapilli tuff, conformably overlying the Jindong Formation. The results of SHRIMP U-Pb zircon age are 97 to 96 Ma, indicating cessation of deposition of the Hayang Group at 97 to 96 Ma by input of pyroclastic materials into the Jinju Subbasin during the explosive volcanic eruptions from the Gyeongsang Volcanic Arc. In comparison with field researches and results of LA-ICP-MS zircon U-Pb age dating (88-85 Ma) of the lowermost part of the Yucheon Group in Gyeongju areas, the volcanic activities that formed Yucheon Group and their influence ranges varied tempo-spatially. This is probably due to distance difference from the volcanic arc or establishment of the paleo-drainage system from the Gyeongsang Volcanic Arc to nearby lowlands.

• Journal of The Korean Association For Science Education
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• v.24 no.5
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• pp.959-976
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• 2004

The purpose of this study was to investigate high school students' ideas related with dinosaur extinction, to classify students' responses types with alternative hypotheses of inconsistent with their ideas, and then to examine their cognitive conflict levels and the degree of ideas change. To investigate students' ideas, we analyzed responses 98 eleventh graders of a high school in Anyang area. The results of this study were as follows: First, most of the students responded a large scale asteroid impact with the cause of dinosaur extinction, and rest of them responded changed Earth's climate accompanying tectonic activity, extreme volcanic activity, shortage of food, disease(virus) and decrease of their habitat. Also, they thought that dinosaur was exterminated not by just one reason but by several complex reasons. Second, the students' responses of alternative hypotheses were classified into six types: rejection, reinterpretation, uncertainty, belief decrease, partial theory change, and theory change. Third, except rejection and reinterpretation types, other four types were arousing of cognitive conflict and the percentage of the students who felt cognitive conflict was 62.3% and that of the students who took the theory change was just 6.1 %.

• The Journal of the Petrological Society of Korea
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• v.17 no.3
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• pp.166-178
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• 2008

The modal analyses on the phenocryst phases and the normative mineralogies from the bulk chemical analyses record that the volcanic rocks related to the Yangsan caldera might been derived from compositionally zoned magma. The volcanic rocks show linearly continuous mineralogical gradients, not only totally in the relations between $SiO_2$ and proportion of phenocryst content, but also within each rock unit in the relations between total phenocryst content and the proportion, Q-Ab-Or and Q-An(Ab-Or) diagrams. The roughly gradational modal variations of the phenocryst phases are shown upward within each rock unit. However, the contents and proportion of the phenocrysts in the Yangsan Tuff and the Hwajeri Formation represent the zigzaggedly undulatory variations. The continuous mineralogical gradients without large gaps define a large zoned magma system in the pre-eruptive, later precollapse and postcollapse magma chambers respectively. The zigzagged variations reflect the intermittent eruptive pulses representing any time gaps.