• Title/Summary/Keyword: 양기석

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Occurrence and Genesis of Amphiboles in Hornblende Gabbro in Guwoonri, Hwacheon and in Otanri, Chuncheon (화천 구운리와 춘천 오탄리 일대에 분포하는 각섬석 반려암체내에 존재하는 각섬석류의 산출양상 및 생성작용)

  • Kim, Guan-Young;Park, Young-Rok
    • The Journal of the Petrological Society of Korea
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    • v.18 no.2
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    • pp.79-91
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    • 2009
  • Jurassic hornblende gabbo intrusives are distributed in Otanri, Chuncheon, and in Guwoonri, Hwacheon located in the northern part of Gyeonggi Massif. The intrusives composed mainly of amphiboles and plagioclase can be divided into two distinct rocks depending on the shape of amphiboles: (i) subspherical amphibole gabbro which has subspherical amphibole phenocryst as a major mafic phase(Sag); (ii) prismatic amphibole gabbro which has prismatic amphiboles as a principal mafic mineral(Pag). Subspherical amphiboles in Sag have higher Cr content and higher Mg($Mg+Fe^{2+}$) ratio relative to the prismatic amphiboles in Pag. This is indicative of conversion of pyroxene into amphibole with pyroxene pseudomorph. Oxygen isotopic results of plagioclase and amphibole separated from the hornblende gabbro suggest that theses minerals have experienced oxygen isotopic exchange with relatively heavy-$^{18}O$fluid for a long period, and magmatic fluid has been involved in the formation of subspherical amphiboles. Amphiboles in hornblende gabbro are composed of distinct species of pargasite, magnesiohornblende, actinolite, which formed at different stages.

Characteristics of Settlement for Non-woven Geotextile through Cyclic Loading Model Test (보강재의 강성도를 고려한 연약지반 표층처리공법 지지력 산정방법에 관한 연구)

  • Ham, Tae-Gew;Seo, Se-Gwan;Cho, Sam-Deok;Yang, Kee-Sok;You, Seung-Kyong
    • Journal of the Korean Geosynthetics Society
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    • v.8 no.2
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    • pp.11-20
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    • 2009
  • This study, as basic research which was intended to develope the surface reinforcement method using reinforcement material which is applicable to very soft ground in Korea, was aimed at proposing the design parameter for the surface ground improvement method. To that end, a wide width tensile test using geotextile, geogrid and steel bar (substitute for bamboo) and 21 kinds of the laboratory model tests with the end restraint conditions of the reinforcement that comprises the constrained and partially constrained (3 types) conditions were conducted. Moreover, a new procedure was proposed to take into account the effect of the stiffness of Reinforce materials on bearing capacity theory of Surface Reinforcement Method for Soft Ground.

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A Study on Determining the Design Parameter ($N_c$, $T_i$) of the Surface Reinforcement Method for Soft Ground (연약지반 표층처리공법 설계정수(지지력계수$N_c$, 인장력$T_i$) 산정방법에 관한 고찰)

  • Ham, Tae-Gew;Seo, Se-Gwan;Cho, Sam-Deok;Yang, Kee-Sok;You, Seung-Kyong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.750-758
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    • 2009
  • This study, as basic research which was intended to develope the surface reinforcement method using reinforcement material which is applicable to very soft ground in Korea, was aimed at proposing the design parameter for the surface ground improvement method. To that end, a wide width tensile test using geotextile, geogrid and steel bar (substitute for bamboo) and 25 kinds of the laboratory model tests with the end restraint conditions of the reinforcement that comprises the constrained and partially constrained (3 types) conditions were conducted. And the result indicated that the modulus of subgrade reaction or $N_c$ value (5.3) apparently overestimated the bearing capacity of very soft ground such as dredged ground. Moreover, as a result of model test by partially constraining the preload of 23.0kgf using geotextile, the effect of bearing capacity($q_1$) appeared to be the largest till the loading stress was $0.4tf/m^2$ due to cohesion, while it reached 75% of the maximum bearing force after $0.4tf/m^2$ due to increase in the effect of bearing capacity($q_2$) caused by the tensile force of the reinforcement. Such results tended to have appeared constantly or very similarly with each other, irrespective of the type of reinforcement (geogrid, steel bar) and constraint conditions.

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A Study on Bearing Capacity Evaluation Method of Surface Reinforcement Method for Soft Ground in Consideration of Stiffness (강성도를 고려한 연약지반 표층처리공법 지지력산정방법에 관한 연구)

  • Ham, Tae-Gew;Seo, Se-Gwan;Cho, Sam-Deok;Yang, Kee-Sok;You, Seung-Kyong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1118-1125
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    • 2009
  • This study, as basic research which was intended to develope the surface reinforcement method using reinforcement material which is applicable to very soft ground in Korea, was aimed at proposing Bearing Capacity Evaluation method for the surface ground improvement method. To that end, a wide width tensile test using geotextile, geogrid and steel bar (substitute for bamboo) and 21 kinds of the laboratory model tests with the end restraint conditions of the reinforcement that comprises the constrained and partially constrained (3 types) conditions were conducted. According to result of tests, Terzaghi's bearing capacity method is adequate to calculate bearing capacity in non-stiff material(geotextile, geogrid). But, It can't adequate to stiff material(bamboo net). So, New bearing capacity method suggest surface reinforcement method of very soft ground which Terzaghi's bearing capacity method modify for effect of stiffness.

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The Evaluation on the Environmental Effect of Coal-Ash and Phosphogypsum as the Evapotranspiration Final Cover Material (증발산 원리를 이용한 매립장 최종 복토공법의 복토재로서 석탄재와 인산석고의 환경적 영향 평가)

  • Yu, Chan;Yang, Kee-Sok
    • Journal of the Korean GEO-environmental Society
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    • v.6 no.1
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    • pp.15-21
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    • 2005
  • In this study, the utilization of coal-ash and phosphogypsum was considered as the evapotranspiration final landfill cover(ET cover) material. Cover material considered was the mixture of the weathered granite soil, coal-ash and phosphogypsum and so we sequentially performed the leaching test, column test and field model test to investigate the environmental effects of mixtures of coal-ash and phosphogypsum. In the leaching test, all materials had lower heavy metal concentration than the regulated threshold values. The column test and the review of related regulations were carried out to determine the optimum mixing ratio(OMR) and OMR was soil(4):coal-ash(1): phosphogypsum(1) on the volume base, which was applied to field model test. Field model tests were continued from February to June, 2004 in the soil box that was constructed with cement block. It was verified that coal-ash and phospogypsum mixed with soil was safe environmentally and the mixture of both wastes could improve the water retention capacity of cover materials.

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Bearing Capacity Characteristic of Dredged and Reclaimed Ground Reinforced by Bamboo Net (대나무 망으로 보강된 준설매립지반의 지지력 특성)

  • Kang, Myoung-Chan;Yang, Kee-Sok;Lee, Song
    • Journal of the Korean Geotechnical Society
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    • v.22 no.8
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    • pp.5-11
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    • 2006
  • A series of large scale plate loading tests are performed to assess bearing capacity characteristic of dredged and reclaimed ground that is reinforced by bamboo net and geotextile as a surface strengthen method. Bearing capacity ratio is distributed from 3.46 to 6.03 for bamboo net and from 2.19 to 3.59 for Geotextile In case of bamboo net, BCR was obtained from 1.6 to 1.7 times than Geotextile. As the comparison of each bearing capacity from test and theory shows, bearing capacity theory for geotextile was not suited for bamboo net. The bearing capacity analysis reinforced by bamboo net shows a good relationship between sand mat thickness (H) / bamboo net space (S), and bearing capacity ratio (BCR).

A Study on the Minimum Zone Algorithm for the Calculation of Roundness (진원도 계산을 위한 Minimum Zone 알고리즘 연구)

  • 이응석;김종길;신양기
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.7
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    • pp.156-161
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    • 2000
  • Least Squares and Minimum Zone method are known for obtaining a datum or a continuous approximate function of measured data. This study is for a Minimum Zone algorithm for a circle, which is useful to obtain the exact roundness from the reference circle of measured data. The proposed method is compared with the Least Squares Limacon method and Chrystal-Peirce algorithm. A computational algorithm for the Minimum Zone circle is suggested and results in less roundness than the other two methods. This Minimum Zone circle method will be used for other geometrical measured data, such as plane or sphere for obtaining the exact flatness or sphericity.

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A CASE OF CHOLESTEROL GRANULOMA OF THE SPHENOID SINUS (접형동에 발생한 콜레스테롤 육아종 1례)

  • 민양기;정하원;유원석
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1991.06a
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    • pp.38-38
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    • 1991
  • 콜레스테롤 육아종은 콜레스테롤 결정이 주위조직에 이물질로 작용하여 육아성 반응 및 골파괴 반응을 유발시키는 질환으로 병리조직학적으로 많은 콜레스테롤 결정이 거대세포를 가진 만성적인 염증성 침윤속에 나타나는것을 특징으로 한다. 이 병변은 아주 드물지만 특징적인 방사선적소견, 병리조직학적 소견과 임상양상으로 쉽게 진단이 된다. 두부에서는 다양한 위치에서 발견되는데 특히 함기화가 잘 된 측두골, 유양동, 고실강에서 많이 보이며 전두골, 상악골, 협골, 인상측두골 및 후두개와에서도 보고되고 있으나 부비동에 발생하는것은 특히 드물다. 부비동에서 발생한 콜레스테롤 육아종의 발생기전은 환기장애설, 배출장애설 및 출혈설 등으로 보고되고 있다. 저자들은 최근 복시와 측두통을 호소하는 50세 여자환자에서 접형동에 발생한 콜레스테롤 육아종이 우측 상안와열 (superior orbital fissure)과 경사대(clivus)를 파괴하며 전교조 (Prepontine cistern)로 확장된 1례를 경험하였기에 임상 증세, 특징적인 전산화단층 및 핵자기공명소견과 병리조직학적인 소견을 문헌 고찰과 함께 보고하는 바이다.

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Hypernews Detection using Sentence BERT Embedding (Sentence BERT 임베딩을 이용한 과편향 뉴스 판별)

  • Lim, Jungwoo;Whang, Taesun;Oh, Dongsuk;Yang, Kisu;Lim, Heuiseok
    • Annual Conference on Human and Language Technology
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    • 2019.10a
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    • pp.388-391
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    • 2019
  • 과편향 뉴스 판별(hyperpartisan news detection)은 뉴스 기사가 특정 인물 또는 정당에 편향되었는지 판단하는 task이다. 이를 위해 feature-based ELMo + CNN 모델이 제안되었으나, 이는 문서 임베딩이 아닌 단어 임베딩의 평균을 사용한다는 한계가 존재한다. 따라서 본 논문에서는 feature-based 접근법을 따르며 Sentence-BERT(SentBERT)의 문서 임베딩을 이용한 feature-based SentBERT 기반의 과편향 뉴스 판별 모델을 제안한다. 제안 모델의 효과를 입증하기 위해 ELMO, BERT, SBERT와 CNN, BiLSTM을 적용한 비교 실험을 진행하였고, 기존 state-of-the-art 모델보다 f1-score 기준 1.3%p 높은 성능을 보였다.

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Cross-Validated Ensemble Methods in Natural Language Inference (자연어 추론에서의 교차 검증 앙상블 기법)

  • Yang, Kisu;Whang, Taesun;Oh, Dongsuk;Park, Chanjun;Lim, Heuiseok
    • Annual Conference on Human and Language Technology
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    • 2019.10a
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    • pp.8-11
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    • 2019
  • 앙상블 기법은 여러 모델을 종합하여 최종 판단을 산출하는 기계 학습 기법으로서 딥러닝 모델의 성능 향상을 보장한다. 하지만 대부분의 기법은 앙상블만을 위한 추가적인 모델 또는 별도의 연산을 요구한다. 이에 우리는 앙상블 기법을 교차 검증 방법과 결합하여 앙상블 연산을 위한 비용을 줄이며 일반화 성능을 높이는 교차 검증 앙상블 기법을 제안한다. 본 기법의 효과를 입증하기 위해 MRPC, RTE 데이터셋과 BiLSTM, CNN, BERT 모델을 이용하여 기존 앙상블 기법보다 향상된 성능을 보인다. 추가로 교차 검증에서 비롯한 일반화 원리와 교차 검증 변수에 따른 성능 변화에 대하여 논의한다.

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