• Title/Summary/Keyword: stability regime

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A Preliminary Study of Flume Experiments on the Flow Velocity for Initial Formation of Bedforms on Bimodal Sand-sized Sediments (이정 사질 퇴적물의 층면구조 형성 속도에 대한 수조 실험 예비 연구)

  • Kim, Hyun Woo;Choi, Su Ji;Choi, Ji Soo;Kwon, Yoo Jin;Lee, Sang Cheol;Kwak, Chang Hwan;Kwon, Yi Kyun
    • Journal of the Korean earth science society
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    • v.37 no.4
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    • pp.218-229
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    • 2016
  • The bedform stability diagram indicates the shape and size of bedforms that will occur to a given grain size and flow velocity. The diagram has been constructed from experimental data which have been mostly acquired by flume experiments. Generally, the flume experiments have been performed on well sorted sediments with unimodal grain size distribution, in order to understand relationship between grain size and flow velocity. According to the diagram, a ripple structure initiates to be formed from lower flow regime flat bed, as the flow velocity increases on the surface of fine-sand or medium-sand sediments. This study aims to verify that the experimental result of bedform stability diagram will be reproduced in our flume experimental systems, and also to confirm that the result is consistent not only on well-sorted sand sediments but also on poorly-sorted sand sediments with bimodal grain size distribution. The experimental results in this study show that initiation of 2D or 3D ripple structure on poorly-sorted sand sediments requires higher flow velocity and shear stress than those for initiation of the structure on well-sorted sand sediments. In general, carbonate sediments are characterized by poor sorting due to inactive hydraulic sorting and bimodal grain size distribution with allochems and matrices. The results suggest that the carbonate depositional system possibly need a higher flow velocity for initial formation of 2D or 3D bedform structures. The reason might be the fact that pulling off and lifting of a grain in poorly sorted sediments require more energy due to sorting, friction, stabilization, armour effects, and their complex interaction. This preliminary study warrants additional experiments under various conditions and more accurate analysis on the relationship between formation of bedforms and grain size distribution.

Geochemistry of tourmalines in the Ilgwang Cu-W breccia-pipe deposit, Southeastern Gyeongsang Basin (경상남도 일광의 각력파이프형 구리(Cu)광상에서 산출되는 전기석의 지구화학)

  • 양경희;장주연
    • The Journal of the Petrological Society of Korea
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    • v.11 no.3_4
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    • pp.259-270
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    • 2002
  • A small granodiorite-quartz monzonitic stock containing sericitic and propylitic alteration assemblages hosts a Cu-W breccia-pipe deposit in the southeastern Cyeongsang basin. The mineralized breccia-pipe contains angular to subangular brecciated fragments of granitic rocks showing clast-supported textures. An assemblage of quartz, tourmalines, sulfide minerals (mainly chalcopyrite, arsenopyrite and pyrrhotite) and calcite was precipitated as a hydrothermal cement between the brecciated fragments. A tourmaline aureole surrounds the breccia pipe. Extensive tourmalinization of the granitic rocks near and within the pipe and no tourmalinization in the sedimentary and volcanic rocks. The tourmalines are marked by Fe-rich, black charcoal-like schorl (80 mol% schorl relative) nearer the schorl-dravite solid solution. The chemical changes in the hydrothermal fluid are reflected by variations in compositional Boning from cores to rims. They generally contain cores with low values of Fe/(Fe+Mg) and high values of Na/(Na+ca) relative to rims. This is because of an increase Fe and Ca contents toward rims. The main trend of these variations is a combination of the exchange vectors Ca(Fe, Mg) $(NaAl)_{- }$ $_1$ and $Fe^{3}^{+}$ $Al_{[-10]}$ $_1$ It is thought that boiling causes the loss of $H_2$ into the vapor phase resulting in the oxidation of Fe in the aqueous phase. pH of the melt would be one of important controlling factors for the tourmaline stability. The tourmalines could be precipitated when the system evolved to the acidic hydrothermal regime as most hydrothermal brines and acidic gases exsolved from the magma. The Ilgwang tourmaline crystallization is products of hypogene orthomagmatic hydrothermal processes that were strongly pipe-controlled.

1970s Korean film and landscape of Others -with 'family community' and 'death' motif (1970년대 한국 영화와 타자들의 풍경 -'가족'과 '죽음' 모티프를 중심으로)

  • Han, Young-Hyeon
    • Journal of Popular Narrative
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    • v.25 no.4
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    • pp.429-465
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    • 2019
  • This paper analyzed the ways in which "others" were reproduced in Korean movies in the 1970s. In the midst of the social changes of the era, such as urbanization due to rapid industrial modernization, many people became laborers for industry in order to obtain the fruits of modernization.But the landscape of others, which was inevitably produced in the process of constructing such subjects, has been limited to analysis that is focused on gender and youth discourse. This article aims to extract the landscape of others in the 1970s by adopting a different perspective. The way in which the other is present can be divided into the following two categories. First, in 1970s film, the family community, in contrast with 1960s film, has disintegrated and cracked, due to the inability of others to enter or leave the community. The desperate perception that the family community can no longer function as a stable foundation or center of the constitution, and that it cannot have a sense of security and belonging,is revealed through the way the others are wandering in and out of the community. Second, 'Death' is an element of social life in the violence of the national ideology of the 1970s, and the everyday exceptional state. The way in which the 'other' is completely eliminated from the normal subjectivity requested by the state and is deported in film reflectshow everyday death or potential death is part of life of the 1970s. Normal life pursued through rapid urbanization and industrialization leads to the death of the other beings, but the way of existence of others is the desperate reality of the 1970s, when the boundaries of the state that provide stability and belonging are broken. As a result, the landscape of others in the 1970s reveals a violent reality that destroys the perfect middle class family discourse that industrial modernization was oriented around in the 1970s, and that produced masses of others who caused numerous deaths. In spite of regime censorship, Korean films were popularly revealing the violence of life brought in by the 1970s, following a detour of representation.

Historical Review on the Security Service for the Royal Household in the "Goryeo" Era (고려시대 왕실호위제도의 사적 고찰)

  • Lee, Sung-Jin;Kim, Eui-Young;Lee, Jong-Hwan
    • Korean Security Journal
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    • no.14
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    • pp.413-429
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    • 2007
  • The Guard over the royal household in the "Goryeo" era was the same as if was over the President or Ruler of a nation today. In those days, a king represented a nation and any threat to the safety of a king could bring the destruction of a nation and the dispersion of the people. by reviewing the change of the 2-Gun 6-Wi system of the era, it can be, summed up as follow, Ther will be suggestions. The Guard might focus on a king's personal safety in the wake of the system of the Silla and Taebong dynasties until the establishment of the Goryeo Dynasty's unique political system. "Goryeo" rebuilt the royal palace in Gyeonyeong-gun to take the shape of unified country after its accomplishment of unification of the late three countries, Then it was afraid of the rebellion and uprising of local powerful clans, The country put them under control and organized the local army with them in the era of Kings, Seongjong, through the kings, Seongjong and Gwangjong. The army system of "Goryeo" consisted of 2-Gun and 6-Wi, and 2-Gun placed above the 6-Wi played the role of the Royal guards, and among the organizations a certain army under the specific name of "Gyeonyong-gun" guarded the kings in the nearest position. An aristocratic culture enjoyed its golden age in the period of stability of the aristocracy of "Goryeo", but afterward in the confusion of the aristocratic disruption and incompatible confrontation the country lost its control, and faced military rebellions by treating civil officials well and ill-treating military officials The safety of kings become unstable with the grasping political power by the military officials, and "Dobang" was established in the era of Choi's family to grasp political power. In the era of Choi Woo, he gathered his men and organized his familys army with them and managed the personnel administration with the civil officials of "Jeongbang and Seobang under his command. Such a fact shows the similarity to today's task of guarding. Considering the facts that "Sambyeolcho, the military ground of the military-men-rule, was at the center of the struggling against Mongolia and that even after the fall of the military regime, they rebelled and fought against Mongolia to the end, we came to know that the nationalism in the era of the military era was great. In the transition of external situations from "Myeong" to "Won"(Chinese dynasties), the conflict between the old "Won"-friendly power and the new "Myeong"-friendly power caused the weakness of the power to guard the royal household, and "Goryeo" at last gave way to the newly rising "Joseon" led by Lee, Seong Gye who won the people's confidence.

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A study on the production techniques and prototype of the mother-of-pearl chrysanthemum pattern box from the Goryeo Dynasty (고려 나전국화넝쿨무늬상자의 제작기법 고찰 및 원형 연구)

  • LEE Heeseung;LEE Minhye;KIM Sunghun;LEE Hyeonju
    • Korean Journal of Heritage: History & Science
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    • v.57 no.1
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    • pp.126-144
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    • 2024
  • The chrysanthemum vine pattern box from the Goryeo Dynasty expresses in great detail the representative features of Goryeo Dynasty lacquerware with mother-of-pearl, such as engraving patterns on the surface of fine mother-of-pearl, expressing vine stems using metal wires, and twisting metal wires to form the boundaries of each patterns. While the lacquerware with mother-of-pearl that remains today from the Goryeo Dynasty has the form of a sutra box and a box with lid, the chrysanthemum vine pattern box that is the subject of this study is in the shape of a box with a separate lid and body, making it difficult to estimate the purpose of production or the stored contents. In this study, we attempted to confirm the formative characteristics of the chrysanthemum vine pattern box in order to confirm its original form, and to investigate its structure and production technique through X-ray transmission. In addition, we attempted to identify the use and production purpose of the box by classifying and comparing the previously known lacquerware with mother-ofpearl from the Goryeo Dynasty by type. As a result of the investigation, fabric was confirmed the bottom of body and inner box through X-ray images. Through this, it was confirmed that the 'Mogsimjeopichilgi'(wooden core grabbing fabric technique) of wrapping the object with fabric was used. And through wood grain, it was possible to confirm the wooden board composition of the part presumed to be the restored part and the part presumed to have had existing Jangseog. In addition, it was confirmed that the joints were connected in a Majdaeim(part to part). Based on the survey results, a total of 14 pieces, including 9 Sutra boxes, 3 boxes, and 2 small boxes, that remain from the Goryeo Dynasty were classified by type and examined for similarity. Among them, there is a "Chrysanthemum Vine Pattern Sutra Box" from a private collection in Japan, a "Black Lacquered Chrysanthemum Arabesque Bun Sutra Box" from the Tokugawa Art Museum, a "Sutra Holder" from the British Museum, and a "Small Box with a Mother-of-Pearl Chrysanthemum Vine Pattern" from a private collection in Korea. The pattern composition of five points was most similar to the subject of this study. As a result of comparing the damage pattern, formative characteristics, and structural features of each part, it is presumed that the sutra holder in the British Museum was transformed into its current form from the original the chrysanthemum vine patterned box. Lastly, in order to confirm the purpose of production, that is, the use of this box, we investigated examples of Tripitaka Koreana printed version produced at a time similar to the social atmosphere of Goryeo at the time. Following the Mongol(元) invasion after the Goryeo military regime at the time, sutras appeared to pray for the stability of the nation and the soul of an individual, and with the development of domestic printing and paper in the 13th century, it gradually coincided with the transition from a scroll to a folded form, and the form of a box changed from a box. It is believed that the storage method also changed.