• Title/Summary/Keyword: North and South Korea

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Sedimentary Facies and Evolution of the Cretaceous Deep-Sea Channel System in Magallanes Basin, Southern Chile (마젤란 분지의 백악기 심해저 하도 퇴적계의 퇴적상 및 진화)

  • Choe, Moon-Young;Sohn, Young-Kwan;Jo, Hyung-Rae;Kim, Yea-Dong
    • Ocean and Polar Research
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    • v.26 no.3
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    • pp.385-400
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    • 2004
  • The Lago Sofia Conglomerate encased in the 2km thick hemipelagic mudstones and thinbedded turbidites of the Cretaceous Cerro Toro Formation, southern Chile, is a deposit of a gigantic submarine channel developed along a foredeep trough. It is hundreds of meters thick kilometers wide, and extends for more than 120km from north to south, representing one of the largest ancient submarine channels in the world. The channel deposits consist of four major facies, including stratified conglomerates (Facies A), massive or graded conglomerates (Facies B), normally graded conglomerates with intraformational megaclasts (Facies C), and thick-bedded massive sandstones (Facies D). Conglomerates of Facies A and B show laterally inclined stratification, foreset stratification, and hollow-fill structures, reminiscent of terrestrial fluvial deposits and are suggestive of highly competent gravelly turbidity currents. Facies C conglomerates are interpreted as deposits of composite or multiphase debris flows associated with preceding hyperconcentrated flows. Facies D sandstones indicate rapidly dissipating, sand-rich turbidity currents. The Lago Sofia Conglomerate occurs as isolated channel-fill bodies in the northern part of the study area, generally less than 100m thick, composed mainly of Facies C conglomerates and intercalated between much thicker fine-grained deposits. Paleocurrent data indicate sediment transport to the east and southeast. They are interpreted to represent tributaries of a larger submarine channel system, which joined to form a trunk channel to the south. The conglomerate in the southern part is more than 300 m thick, composed of subequal proportions of Facies A, B, and C conglomerates, and overlain by hundreds of m-thick turbidite sandstones (Facies D) with scarce intervening fine-grained deposits. It is interpreted as vertically stacked and interconnected channel bodies formed by a trunk channel confined along the axis of the foredeep trough. The channel bodies in the southern part are classified into 5 architectural elements on the basis of large-scale bed geometry and sedimentary facies: (1) stacked sheets, indicative of bedload deposition by turbidity currents and typical of broad gravel bars in terrestrial gravelly braided rivers, (2) laterally-inclined strata, suggestive of lateral accretion with respect to paleocurrent direction and related to spiral flows in curved channel segments around bars, (3) foreset strata, interpreted as the deposits of targe gravel dunes that have migrated downstream under quasi-steady turbidity currents, (4) hollow fills, which are filling thalwegs, minor channels, and local scours, and (5) mass-flow deposits of Facies C. The stacked sheets, laterally inclined strata, and hollow fills are laterally transitional to one another, reflecting juxtaposed geomorphic units of deep-sea channel systems. It is noticeable that the channel bodies in the southern part are of feet stacked toward the east, indicating eastward migration of the channel thalwegs. The laterally inclined strata also dip dominantly to the east. These features suggest that the trunk channel of the Lago Sofia submarine channel system gradually migrated eastward. The eastward channel migration is Interpreted to be due to tectonic forcing imposed by the subduction of an oceanic plate beneath the Andean Cordillera just to the west of the Lago Sofia submarine channel.

Geometry and Kinematics of the Yeongdeok Fault in the Cretaceous Gyeongsang Basin, SE Korea (한반도 동남부 백악기 경상분지 내 영덕단층의 기하와 운동학적 특성)

  • Seo, Kyunghan;Ha, Sangmin;Lee, Seongjun;Kang, Hee-Cheol;Son, Moon
    • The Journal of the Petrological Society of Korea
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    • v.28 no.3
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    • pp.171-193
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    • 2019
  • This study aims to identify the geometry and internal structures of the Yeongdeok Fault, a branch fault of the Yangsan Fault, by detailed mapping and to characterize its kinematics by analyzing the attitudes of sedimentary rocks adjacent to the fault, slip data on the fault surfaces, and anisotropy of magnetic susceptibility (AMS) of the fault gouges. The Yeongdeok Fault, which shows a total extension of 40 km on the digital elevation map, cuts the Triassic Yeongdeok Granite and the Cretaceous sedimentary and volcanic rocks with about 8.1 km of dextral strike-slip offset. The NNW- or N-S-striking Yeongdeok Fault runs as a single fault north of Hwacheon-ri, Yeongdeok-eup, but south of Hwacheon-ri it branches into two faults. The western one of these two faults shows a zigzag-shaped extension consisting of a series of NNE- to NE- and NNW-striking segments, while the eastern one is extended south-southeastward and then merged with the Yangsan Fault in Gangu-myeon, Yeongdeok-gun. The Yeongdeok Fault dips eastward with an angle of > $65^{\circ}$ at most outcrops and shows its fault cores and damage zones of 2~15 m and of up to 180 m wide, respectively. The fault cores derived from several different wall rocks, such as granites and sedimentary and volcanic rocks, show different deformation patterns. The fault cores derived from granites consist mainly of fault breccias with gouge zones less than 10 cm thick, in which shear deformation is concentrated. While the fault cores derived from sedimentary rocks consist of gouges and breccia zones, which anastomose and link up each other with greater widths than those derived from granites. The attitudes of sedimentary rocks adjacent to the fault become tilted at a high angle similar to that of the fault. The fault slip data and AMS of the fault gouges indicate two main events of the Yeongdeok Fault, (1) sinistral strike-slip under NW-SE compression and then (2) dextral strike-slip under NE-SW compression, and shows the overwhelming deformation feature recorded by the later dextral strike-slip. Comparing the deformation history and features of the Yeongdeok Fault in the study area with those of the Yangsan Fault of previous studies, it is interpreted that the two faults experienced the same sinistral and dextral strike-slip movements under the late Cretaceous NW-SE compression and the Paleogene NE-SW compression, respectively, despite the slight difference in strike of the two faults.

Some Peculiarities of Structure and Growth of Larch Stands in Western Mongolia

  • Tsogtbaatar, J.;Battulga, P.
    • The Korean Journal of Quaternary Research
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    • v.18 no.2 s.23
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    • pp.107-107
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    • 2004
  • In this paper we have introduced some results of study on stand growth pattern and stand structure of larch forest which are located in selected forest sites of Khangai and Gobi-Altai mountain ranges of Mongolia. Our investigations showed that growth intensity and stand structure in western Mongolia are very specific from the other forest vegetation zones of Mongolia. Studies on the stand structure and growth trend indicate that tree types of stand structure and different types of growth of Larix sibrica are very common in Western Mongolia. These peculiarities of stand structure and growth of larch stands in Western Monolia could be used for inventory work and an improvement of the forest management in Western Mongolian region. The larch tree is the dominant tree species in Western Mogolia. Forest cover of the region is about 15%, which is two times higher than the country's average. In this region forest area is divided into 4 forest sub-regions: the Central Khangai, Western Khangai, North Eastern Khangai and South Easterun Khangai sub-regions including taiga, pseudo taiga, sub taiga, sub-alpine and forest steppe belts. Silviculture practices and forest research management request to study forest growth trends in local and general conditions, which means to indicate a change of taxonomic characteristics of stand from time to time including diameter, height, basal area, growth stock etc. The forest management practice mostly uses tables of forest growth and yield based on the results of long term research on forest growth. Forest yield tables and other relevant forest standards of Russia are used for the forest inventory and forest management. They are not able to determine forest structure and growth peculiatities of Mongolian forests. Studies on forest resource assessment in Mongolia indicate that after logging operations and forest fires the natural regeneration of desired species such as pine and larch often does not succeed. This situation forces to take a different approach of forest management and silviculture practice depending on the stand structure and growth rate of the forest stands. According to our investigation in last years, forest growth pattern of larch forest depends mostly on stand structure, stand age and growth condition including forest soil, climate and location in different slopes. Due to improve environmental function of forest ecosystem in the region, it is needed to conduct very comprehensive study of high mountain forest ecosystem in selected sub-regions.

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Skarn-Ore Associations and Phase Equilibria in the Yeonhwa-Keodo Mines, Korea (태백산광화대(太白山鑛化帶) 연화(蓮花)-거도광산(巨道鑛山)에 있어서의 스카른과 광석광물(鑛石鑛物)의 수반관계(隨伴關係) 및 상평형(相平衡))

  • Yun, Suckew
    • Economic and Environmental Geology
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    • v.16 no.1
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    • pp.1-10
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    • 1983
  • The Yeonhwa (I, II) and Keodo mines, neighboring in the middle part of the Taebaegsan mineral belt, contain three distinct classes of skarn deposits: the zinc-lead skarn at Yeonhwa (I, II), the iron skarn at Keodo south (Jangsan orebodies), and the copper skarn at Keodo north (78 orebodies). The present study characterizes the three classes of skarn deposits mainly in terms of skarn/ore associations examined from chemical compositional point of view, and applies existing quantitative phase diagrams to some pertinent mineral assemblages in these mines. At Yeonhwa I the Wolam I orebody shows a vertical variation in skarn minerals ranging from clinopyroxene/garnet zone on the lower levels through clinopyroxene (without garnet) zone on the intermediate levels, and finally to rhodochrosite veins on the upper levels and surface. Ore minerals, sphalerite and galena, associate most closely with the intermediate clinopyroxene zone. At Keodo, the Jangsan iron skarn hosted in quartz monzodiolite as a typical endoskarn, shows a skarn zoning, from center of orebody to outer side, magnetite zone, magnetite/garnet zone, garnet clinopyroxene zone, and clinopyroxene/epidote/plagioclase zone. The 78 copper skarn in the Hwajeol limestone indicates a zoning, from quartz porphyry side toward limestone side, orthoclase/epidote zone, epidote/clinopyroxene zone, and clinopyroxene/garnet zone; chalcopyrite and other copper sulfides tend to be in clinopyroxene/garnet zone. Mioroprobe analyses of clinopyroxenes and garnets from the various skarn zones mentioned above revealed that the Yeonhwa zinc/lead skarns are characterized by johansenitic clinopyroxene (Hd 25-78, Jo 15-23) and manganoan andraditic garnet (Ad 13-97, Sp 1-24), whereas the Jangsan iron skarn at Keodo by Mn-poor diopsidic clinopyroxene (Di 78-93, Jo 0.2-1.0) and Mn-poor grossularitic grandite (Gr 65-77, Sp 0.5-1.0). The 78 copper skarn at Keodo is characterized by Mn-poor diopsidic-salite (Di 66-91, Jo 0.2-1.1) and Mn-poor andraditic grandite(Ad 40-74, Sp 0.5-1.1). The compositional charateristics of iron, copper, and zinc-lead skarns in the Yeonhwa-Keodo mines are in good correlations with those of the foreign counterparts. Compiling a $T-XCO_2$ phase diagram for the Jangsan endoskarns, a potential upper limit of temperature of the main stage of skarn formation is estimated to be about $530^{\circ}C$, and a lower limit to be $400^{\circ}C$ or below assuming $XCO_2=0.05$ at P total=1kb. Applying a published log $fS_2$-log $fo_2$ diagram to the Keodo 78 and Yeonhwa exoskarns, it is revealed that copper sulfides and zinc-lead sulfides do not co-exist stably below log $fS_2=-4$ and log $fO_2=-23$ at $T=400^{\circ}C$ and ${\times}CO=1$ atm.

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Optimization of Extrusion Cooking Conditions for the Preparation of Seasoning from Manila Clam Ruditapes philippinarum (바지락(Ruditapes philippinarum) 조미소재 제조를 위한 Extrusion Cooking 공정의 최적화)

  • Shin, Eui-Cheol;Kwak, Dongyun;Ahn, Soo-Young;Kwon, Sangoh;Choi, Yunjin;Kim, Dongmin;Choi, Gibeom;Boo, Chang-Guk;Kim, Seon-Bong;Kim, Jin-Soo;Lee, Jung Suck;Cho, Suengmok
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.6
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    • pp.823-833
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    • 2020
  • The Manila clam Ruditapes philippinarum, is an important marine bivalve that is widely distributed along the west and north coasts of South Korea. It has been used in a variety of Korean foods owing to its superior umami taste. In the present study, we developed a flavoring with an excellent sensory preference from Manila clam using extrusion cooking processing. Optimization of extrusion cooking conditions was performed using response surface methodology (RSM). Barrel temperature (X1, 140-160℃) and screw speed (X2, 400-560 rpm) of the extruder were chosen as independent variables. The dependent variable was overall acceptance (Y, points). The estimated optimal conditions were as follows: overall acceptance (Y): X1=140℃ and X2=560 rpm. The indicated value of the dependent variable overall acceptance (Y) under the optimal conditions was 8.94 points, which was similar to the experimental value (8.82 points). Overall acceptance of the Manila clam flavoring was related to its umami and Manila clam tastes. The electronic nose and tongue results successfully segregated different clusters of the samples between the lowest and highest sensory scores. The sample with the highest sensory score had higher sourness, umami, and sweetness intensities, and the lowest sensory scored sample showed more off-flavor compounds.

Longitudinal Distribution of Zooplankton at 10.5°N in the Northeastern Pacific (북동태평양 북위 10.5°에서 동물플랑크톤의 경도별 분포 특성)

  • Kang, Jung-Hoon;Cho, Kyu-Hee;Son, Ju-Won;Kim, Woong-Seo
    • Ocean and Polar Research
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    • v.29 no.4
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    • pp.283-295
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    • 2007
  • We investigated the longitudinal variations in zooplankton abundances and their related physicochemical properties at nine stations located between $136^{\circ}W$ and $128^{\circ}W$ at $10.5^{\circ}N$ in the northeastern Pacific in summer 2004. Temperature, salinity, inorganic nutrients, chlorophyll-a (hereafter chl-a) and zooplankton ($>200\;{\mu}m$) were sampled within the depth from the surface to 200 m depth at $1^{\circ}$ longitude intervals. Zooplankton($>200\;{\mu}m$) samples were vertically collected at two depth intervals from surface to 200 m, consisting of surface mixed and lower layers (thermocline$\sim$200 m). Longitudinal distributional pattern of hydrological parameters (especially salinity) was physically influenced by the intensity of westward geostrophic current passage relating to the NEC (North Equatorial Current). Data from the longitudinal survey showed clear zonal distributions in the hydrological parameters(temperature, salinity and nutrients). However, spatial patterns of the chl-a concentrations and zooplankton abundances were mostly independent of the zonal distributions of hydrological parameters. The two peaks of zooplankton abundance in the surface mixed layer were characterized by different controlling factors such as bottom-up control from nutrients to zooplankton ($129^{\circ}W$) and accumulation by increment of friction force and taxonomic interrelationship ($133^{\circ}$ and $134^{\circ}W$). Divergence-related upwelling caused introduction of nutrients into surface waters leading to the increment of chl-a concentration and zooplankton abundances ($129^{\circ}W$). Increased friction force in relation to reduced flow rates of geostrophic currents caused accumulation of zooplankton drifting from eastern stations of study area($133^{\circ}$ and $134^{\circ}W$). Besides, high correlation between immature copepods and carnivorous groups such as chaetognaths and cyclopoids also possibly contributed to the enhanced total abundance of zooplankton in the surface mixed layer (p<0.05). Zooplankton community was divided into three groups (A, B, C) which consecutively included the eastern peak of zooplankton($129^{\circ}W$), the western peak($133^{\circ}$ and $134^{\circ}W$) and high nutrient but low chl-a concentration and zooplankton abundance ($136^{\circ}W$). Moreover, Group B corresponded to the westward movement of low saline waters(<33.6 psu) from 128 to $132^{\circ}W$. In summary, longitudinal distributions of zooplankton community was characterized by three different controlling factors: bottom-up control ($129^{\circ}W$), accumulation by increased friction force and relationships among zooplankton groups ($133^{\circ}$ and $134^{\circ}W$), and mismatch between hydrological parameters and zooplankton in the high nutrient low chlorophyll area ($136^{\circ}W$) during the study period.

Molecular Phylogenetic Study of the Endangered Land Snail Satsuma myomphala Based on Metallothionein Gene. (Metallothionein 유전자를 기초로 한 멸종위기 육상 달팽이 Satsuma myomphala (거제외줄달팽이) 의 분자계통학적 연구)

  • Sang, Min Kyu;Kang, Se Won;Hwang, Hee-Ju;Chung, Jong Min;Song, Dae Kwon;Min, Hye Rin;Park, Jie Eun;Ha, Hee Cheol;Lee, Hyun Jun;Hong, Chan Eui;Ahn, Young Mo;Park, So Young;Park, Young-Su;Park, Hong Seog;Han, Yeon Soo;Lee, Jun Sang;Lee, Yong Seok
    • The Korean Journal of Malacology
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    • v.32 no.4
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    • pp.263-268
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    • 2016
  • Metallothionein (MT) family of metal-binding proteins are involved in maintaining homeostasis and heavy metal poisoning. Recently, MT has been considered as a biomarker that can identify a particular species, very similar to the use of cytochrome oxidase I (COI) gene. Satsuma myomphala species of land snails have been reported from North-East Asia, including South Korea and Japan. In particular, the land snail species have been known from only a limited area of Geoje Island, Gyeongsangnam-do province of South Korea. Genetic studies of S. myomphala has been limited with only 6 nucleotide, 2 protein registered on the NCBI server. For elucidating the genetic information of S. myomphala, we conducted RNA sequencing analysis using Illumina HiSeq 2500 next-generation platform. We screened the MT gene from the RNA-Seq database to confirm the molecular phylogenetic relationship. After sequencing, the de novo analysis and clustering generated 103,774 unigenes. After annotation against PANM database using BLAST program, we obtained MT sequence of 74 amino acid residues containing the coding region of 222 bp. Based on this sequence, we found about 53 sequences using the BLAST program in NCBI nr database. Using ClustalX alignment, Maximum-Likehood Tree of MEGA program, we confirmed the molecular phylogenetic relationships that showed similarity with mollusks such as Helix pomatia and H. aspersa, Megathura crenulata.

Recent Changes in Bloom Dates of Robinia pseudoacacia and Bloom Date Predictions Using a Process-Based Model in South Korea (최근 12년간 아까시나무 만개일의 변화와 과정기반모형을 활용한 지역별 만개일 예측)

  • Kim, Sukyung;Kim, Tae Kyung;Yoon, Sukhee;Jang, Keunchang;Lim, Hyemin;Lee, Wi Young;Won, Myoungsoo;Lim, Jong-Hwan;Kim, Hyun Seok
    • Journal of Korean Society of Forest Science
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    • v.110 no.3
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    • pp.322-340
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    • 2021
  • Due to climate change and its consequential spring temperature rise, flowering time of Robinia pseudoacacia has advanced and a simultaneous blooming phenomenon occurred in different regions in South Korea. These changes in flowering time became a major crisis in the domestic beekeeping industry and the demand for accurate prediction of flowering time for R. pseudoacacia is increasing. In this study, we developed and compared performance of four different models predicting flowering time of R. pseudoacacia for the entire country: a Single Model for the country (SM), Modified Single Model (MSM) using correction factors derived from SM, Group Model (GM) estimating parameters for each region, and Local Model (LM) estimating parameters for each site. To achieve this goal, the bloom date data observed at 26 points across the country for the past 12 years (2006-2017) and daily temperature data were used. As a result, bloom dates for the north central region, where spring temperature increase was more than two-fold higher than southern regions, have advanced and the differences compared with the southwest region decreased by 0.7098 days per year (p-value=0.0417). Model comparisons showed MSM and LM performed better than the other models, as shown by 24% and 15% lower RMSE than SM, respectively. Furthermore, validation with 16 additional sites for 4 years revealed co-krigging of LM showed better performance than expansion of MSM for the entire nation (RMSE: p-value=0.0118, Bias: p-value=0.0471). This study improved predictions of bloom dates for R. pseudoacacia and proposed methods for reliable expansion to the entire nation.

A Study on the Common Features of Western Clothing Style and the Style of Korean clothing - Focusing on the Three Kingdom and Unified Shilla era - (우리 나라 복식(服飾)과 서역복식간(西域服飾間)의 공통성(共通性)에 관(關)한 연구(硏究) - 삼국시대(三國時代), 통일신라시대( 統一新羅時代)를 중심(中心)으로 -)

  • Jeun, Jee-Eun;Shim, Hwa-Jin
    • Journal of Fashion Business
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    • v.5 no.4
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    • pp.127-143
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    • 2001
  • This thesis looks into the characteristics and compares the clothing styles between the Three Kingdom to the Unified Shilla era. The purpose of this study is to see what common themes exists between the foundation of Korean clothing and how it has evolved and through see to what extent the Chinese influence has been to Korean clothing culture. Also by explaining the originality and creativity of Korean clothing, we will be able to make clear the status of Korean culture. These findings include the following; 1. The Korean strait line Gik-ryong Kyo-im can also be found at the Gochang region in the west. 2. The Ban-ryong-ui, worn by the aristocrats of the Three kingdom and Unified Shilla era, began to appear from the nobles from the Nam-Buk cho(South-north era). This combined with a Bokdu(headwear) became a part of casual dress wear. 3. Go(pants) became a traditional part of clothing for Unified Shilla and the west. 4. Ban-bi and Bae-dang, all forms of Bansu-ui ( short sleeve), came from Chinas Kucha and Hotan and came to Korea. 5. Chinas Pae-baek and Pae-za (Shawl) which is the same as Unified Shillas Peo was also to be found to have come from the west. 6. The way a different color line was added to clothing both can be found in Korean and western clothing. Similarities to material used are; First, expensive wool was used and mostly originated from the west. From far away Rome came the O-saek-gae (Five-color wool). Secondly, Kong-gak me (peacock feather) and Bi-chi mo were all originated from the west. Third, Sil-sil is stated in the Sam-kuk Sa-ki (Three Kingdom records) as being prohibited to be worn by Jin-gol women (Highest nobility during Shilla era) as headwear or comb (pin) or as a comb(pin) for yuk-doo poom ( 6th class nobility) women. Suggesting that it existed and other sources tell us that it came from Tashkent region of Russia and was a jewelry of some sort. From what we have seen above, we can see the similarities between Korean and western clothing cultures and that these interactions not only occurred with China but with many other nations. We can see that our ancestors were creative and original that when importing foreign cultures that they transformed them into a Korean style. That these foreign cultures were transformed into our own style is good evidence to these facts.

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Analysis of Microclimate and Conservation Environment of the Stone Buddha and Shrine in Unjusa Temple, Hwasun, Korea (화순 운주사 석조불감의 보존환경 및 미기상 분석)

  • Park, Sung-Mi;Lee, Chan-Hee;Lee, Myeong-Seong;Kim, Sa-Dug
    • Economic and Environmental Geology
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    • v.42 no.1
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    • pp.73-84
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    • 2009
  • The stone Buddha and Shrine of Unjusa temple (Korean Treasure No. 797) at Hwasun formed in Koryo Dynasty is unique style which faces each other the back parts of south and north within the stone Shrine. The stone Buddha and Shrine is highly evaluated in historical, artistic and academic respects. But, the stone properties have been exposed in the open system various aspects of degradations weathered for a long time without specific protective facilities. To inquire into relative deterioration and environmental factor, air temperature and relative humidity of the stone Buddha and Shrine were monitored for a year of the indoor and outdoor, respectively. As a result, the temperature shows increase and decrease according to the seasons in the tendency to clear. While the relative humidity is high to keep all four seasons. Highly relative humidity environment induces dew condensation on the interior of stone Buddha and Shrine. The dew condensation is recorded at the spring, summer and winter season. The summer season is double the total of spring and winter season. In the case of summer, dew condensation is long time continued due to high temperature and relative humidity that is kept by more than nearly 100%. There is progress towards chemical weathering throughout dissolve rock properties and alteration on the rock surface. In the case of winter, dew condensation is not kept for a long time as summer. In the winter, which showing a below zero may add physical weathering throughout moisture that happen by dew condensation to repeat freezing and thawing. Therefore, the reduction plan of the relative humidity effect on dew condensation should be prepared.