• 한국지구과학회:학술대회논문집
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• 2005.02a
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• pp.138-144
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• 2005

석류석은 변성 온도와 압력을 계산하는 지온지압계에 널리 사용되며, 또한 이들 내부엽리와 외부엽리와의 접촉 관계를 이용하여 상대적인 변형작용의 시기를 밝히는 데 이용되어져 왔다. 석류석 반상변정 내의 내부 엽리 조직에 대한 정량적인 해석과 내부 미세 구조와 화학적 누대구조와의 관계에 대한 접근 방법은 석류석이 형성되는 동안에 온도-압력-변형작용의 진화 과정을 보다 정량적으로 해석할 수 있을 뿐만 아니라, 절대 연령 자료와 결합은 조산 운동 동안 발생하는 다변성/다변형 작용의 특징 보여주는 온도-압력-변형-시간 경로를 규명할 수 있다. 미국 메사추세츠 주 북중부 지역에서 십자석, 남정석과 함께 산출되는 석류석 반상변정은 온도-압력이 증가(540-570 $^{\circ}C$, 4.0-5.0 kbar에서 620-637 $^{\circ}C$, 7.9-8.8 kbar 까지) 하면서 성장하였다. 또한 이와 같은 변성작용 동안 압축 변형 방향은 다음과 같은 순서로, NE-SW, NW-SE, N-S 그 다음 E-W 방향으로 변화하였다. 결론적으로 이와 같은 변성작용과 변형작용은 주로 고생대 중기 데본기 동안에 일어났던 아카디안 조산운동으로 특징 지워 지며, 후기 알레게니안 조산운동에 부분적으로 영향을 받은 것으로 판단한다.

• Journal of the Korean earth science society
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• v.21 no.3
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• pp.302-314
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• 2000

Keumseong area in the southern part of the Jecheon city, the Ogcheon Belt, consists of Precambrian Dangdusan Metamorphic Complex, Dori Formation of the Choseon Supergroup, and Jurassic Jecheon Granite. The Dangdusan Metamorphic Complex consists of quartz schist, mica schist. quartzite and pegmatite. The Dori Formation is composed of mainly laminated limestone. The rocks in the study area have been undergone at least three phases of deformations since Paleozoic period. The Dangdusan Metamorphic Complex is outcrop at three areas in the study area, which are exposed along the faults and occurred as inlier within the Dori Formation. Previous authors interpreted the uplift of the Dangdusan Metamorphic Complex by the Dangdusan Fault, but we could not find any evidences related to the Dangdusan Fault. Thus, we interpret the uplift of the Dangdusan Metamorphic Complex due to the D$_2$ Weolgulri and Dangdusan thrusts and post-D$_2$ Jungbodeul, Kokyo and Jungjeonri faults. The uplift of the Busan Metamorphic Complex to the west of the study area was interpreted by ductile deformation. However, the Dangdusan Metamorphic Complex is formed by brittle thrusts and faults in this study. According to deformation sequence, the characters of deformations in the Choseon and Ogcheon suprergroups had been changed from ductile to brittle deformations through the time. Therefore, we interpret the Dangdusan Metamorphic Complex is exposed later than the Busan Metamorphic Complex.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2003.05a
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• pp.51-51
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• 2003

임진강대의 변성이질암은 전형적인 바로비안형 변성분대를 보이며, 남쪽으로 갈수록 변성도가 증가하여 석류석$\longrightarrow$십자석$\longrightarrow$남정석 대를 정의한다. 우리는 반상변정의 성장과 여러번에 걸친 광역변형작용의 연관성을 밝히기 위해 광물의 반응관계와 성장순서 그리고 미구조(microstructure)를 -특히 석류석에 대해서- 연구하였다. 임진강대는 크게 세 번에 걸쳐 변형작용을 받은 것으로 해석된다: (1) 지각 두께의 증가에 수반된 압축변형작용 (D$_{n-1}$), (2) 주 엽리(Sn)를 만든 변형작용(Dn), 그리고 (3) 연성전단작용에 수반된 신장변형작용(D$_{n+1}$ ). 석류석대의 석류석 반상변정에서는 약간 휘어진 포유물 궤적(inclusion trail)이 주 엽리면에 대해 연속적이며, 이는 Dn과 동시기에 반상변정이 생성되었음을 지시한다. 이러한 석류석은 녹니석과 백운모로 구성된 주 엽리를 치환하면서 자라기 때문에, 녹니석+백운모+석영=석류석+흑운모+$H_2O$의 반응에 의해 만들어진 것으로 해석된다. 석류석 자형변정(idioblast)이 주 엽리를 자르면서 성장하기도 하는데, 이는 Dn 이후에도 석류석이 후구조(post-tectonic) 광물로 성장했음을 지시한다. 또한, 이러한 석류석은 흑운모를 치환하기 때문에, 동구조(syn-tectonic) 석류석의 생성반응에서와는 달리 흑운모가 반응물임을 알 수 있다. 한편, 십자석대의 석류석은 포유물 궤적에 의해 정의되는 S$_{n-1}$면이 주 엽리면과 사각을 이루며 단속적이기 때문에, D$_{n-1}$과 Dn 사이에 자란 것으로 해석된다. 이와는 대조적으로 십자석은 주 엽리를 치환하면서 자라고 있어서 Dn과 동시기 혹은 Dn 이후에 자랐을 것으로 해석된다..의 환경문제를 발생하지 않으며, 공정액에 첨가제를 투입하지 않으므로 순환형 친환경공정으로 각광받을 수 있다. 본 연구에서는 고온, 고농도의 NaOH 수용액의 처리에 적합한 막소재와 발생될 수 있는 제반 문제점 등을 파악하였고, 장기간의 실험을 거쳐 최적 투과 압력(Trans membrane pressue), 세정 조건 및 주기, 막재질에 있어서 보강하여야 할 Point, 최적 운전 조건들을 토출해 내었고, 향후 실제 Plant에 적용할 계획이다.는 양적으로 다른 두 가지의 유사한 마그마가 수반된 것으로 추정된다. 것으로 추정된다.를 사용하지 않음으로써 효과적이고 만족할 만한 심근보호 효과를 보였다.를 보였다.4주까지에서는 비교적 폐포는 정상적 구조를 유지하면서 부분적으로 소폐동맥 중막의 비후와 간질에 호산구 침윤의 소견이 특징적으로 관찰되었다. 결론: 분리 폐 관류는 정맥주입 방법에 비해 고농도의 cisplatin 투여로 인한 다른 장기에서의 농도 증가 없이 폐 조직에 약 50배 정도의 고농도 cisplatin을 투여할 수 있었으며, 또한 분리 폐 관류 시 cisplatin에 의한 직접적 폐 독성은 발견되지 않았다이 낮았으나 통계학적 의의는 없었다[10.0%(4/40) : 8.2%(20/244), p>0.05]. 결론: 비디오흉강경술에서 재발을 낮추기 위해 수술시 폐야 전체를 관찰하여 존재하는 폐기포를 놓치지 않는 것이 중요하며, 폐기포를 확인하지 못한 경우와 이차성 자연기흉에 대해서는 흉막유착술에 더 세심한 주의가 필요하다는 것을 확인하였다. 비디오흉강경수술은 통증이 적고, 입원기간이 짧고, 사회로의 복귀가 빠르며, 고위험군에 적용할 수 있고, 무엇보다도 미용상의 이점이 크다는 면에서 자연기흉에 대해 유용한 치료방법임에는 틀림이 없으나 개흉술에 비해 재발율이 높고 비용이 비싸다는 문제가 제기되고 있는 만큼 더 세심한 주의와 장기 추적관찰이 필요하리라 사료된다.전 도부타민 심초음파는 관상동맥우회로술 후

• The Journal of the Petrological Society of Korea
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• v.6 no.3
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• pp.166-184
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• 1997

The Wondong caldea is a deeply eroded structure that offers spectacular exposures through the core and margins of a resurgent caldera. The Wondong Tuff and the postcollapse intrusions range from medium-silica rhyolite to rhyodacite in composition and the postcollapse lava and tuff, preresurgent and resurgent intrusions also range from medium-silica rhyolite to an-desite, which jump to gap dacite composition. The continuous compositional zonations generally define a large stratified magma system in the postcollapse and resurgent magma chamber. Isotopic and trace element evidence suggest that the compositional zonations might have resulted from the differentiations from crystal fractionations of a parental andesitic magma, accompanying a little contamination from the crustal assimilations near the chamber roof and wall. But chemically and isotopically distinct late intusions might have resulted from emplacement of any different magma batch.

• The Journal of the Petrological Society of Korea
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• v.19 no.1
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• pp.31-49
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• 2010

Nearly NS-trending Fe-Ti ore bodies intermittently occur in the Hadong anorthosites, south Korea, irrespective of the rock types of the anorthosites. In order to determine their occurrence mode and deformation history, we collected the features of occurrence and geological structures in the field, petrographic features using thin sections of the principal constituent rocks, and geochemical data of ilmenites in the ore body using electron probe microanalysis. Fe-Ti ore bodies examined in this study are divided into two types: dike- and lamina-types. It is steadily supported that the dike-type has intruded into the anorthositic rocks after their emplacement and solidification. And the laminar-type is probably a result of the mylonitization and transposition of the dike-type ore bodies parallel to the shear planes, due to later strong dextral ductile shearing. In the meantime, the Fe-Ti ore bodies have experienced the stronger dextral shearing in the more northern part of the study area, i.e. Cheongryong-ri, Wolhoeng-ri, Jonghwa-ri, and Jayangri and Baekun-ri in ascending order of its strength, together with the less content of $TiO_2$. All ilmenites of the ore bodies have very similar chemical composition, as pure ilmenite of 52~55 wt.% in $TiO_2$ content, irrespective of the occurrence mode and degree of later ductile shearing of the ore bodies. And they didn't experience to exsolve into magnetite. The structural data indicate that the Hadong anorthosites have deformed by NNE-trending folding, intrusion of the Fe-Ti ore bodies, NNW~NNE-trending dextral ductile shearing, NW~NNW-trending sinistral semi-brittle shearing, and intrusion of NNE~NE-trending mafic dykes in descending order of chronology after the formation of foliation of the anorthositic rocks. The foliation is interpreted as a result of the accumulation of crystals that settle out from the magma by the action of gravity.

• Economic and Environmental Geology
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• v.52 no.2
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• pp.159-168
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• 2019

The western Gyeonggi Massif, where records evidence of Phanerozoic subduction/collision tectonics, is an important area to understand the crustal evolutionary history of the Korean Peninsula. This study presents geometric and kinematic characteristics of the geological structures of the Taean Formation in the Gomseom area, southwestern Gyeonggi Massif. We interpreted the geometric relationships between structural elements, and conducted stereographic and down-plunge projections for structural domains. As a result, at least three different deformational events ($D_1$, $D_2$ and $D_3$) are recognized in the study area. In the first deformational event ($D_1$), regional foliations being well defined by the preferred orientation of muscovite and biotite were formed. In the second deformational event ($D_2$), NNE-trending low-angle contractional faults and related crenulation lineations/cleavages were formed. The crenulation lineations shallowly plunge toward SSW~SSE or NNW~NNE. In the third deformational event ($D_3$), SE-plunging folds and NE-trending high-angle faults were formed as 'fault-related fold' and 'fold-accommodation fault', indicating that the $D_3$ folds and faults are genetically linked to each other. This contribution provides important insights into the structural evolution of the Taean Formation along western Gyeonggi Massif, where had evolved as subduction/collisional orogenic belts in the East Asia.

• Journal of the Korea Concrete Institute
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• v.19 no.1
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• pp.121-130
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• 2007

To investigate the enhancement in strength and deformation capacities of concrete confined by FRP composites, tests under axial loads were carried out on three groups of thirty six short columns in circular section with diverse GFRP confining reinforcement. The major test variables considered include fiber content or orientation, wrap or tube type by varying the end loading condition, and continuous or discontinuous confinement depending on the presence of vortical spices between its two halves. The circumferential FRP strains at failure for different types of confinements were also investigated with emphasis. Various analytical models capable of predicting the ultimate strength and strain of the confined concrete were examined by comparing to observed results. Tests results showed that FRP wraps or tubes provide the substantial increase in strength and deformation, while partial wraps comprising the vertical discontinuities fail in an explosive manner with less increase in strength, particularly in deformation. A bilinear stress-strain response was observed throughout all tests with some variations of strain hardening. The failure hoop strains measured on the FRP surface were less than those obtained from the tensile coupons in all tests with a high degree of variation. In overall, existing predictive equations overestimated ultimate strengths and strains observed in present tests, with a much larger scatter related to the latter. For more accuracy, two simple design- oriented equations correlated with present tests are proposed. The strength equation was derived using the Mohr-Coulomb failure criterion, whereas the strain equation was based on entirely fitting of test data including the unconfined concrete strength as one of governing factors.

• Journal of the Korea Concrete Institute
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• v.13 no.6
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• pp.629-636
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• 2001

To apply the research results to the design and the construction of the high rise buildings, long-term behavior of reinforced concrete structure have been widely studied. However, shoring and reshoring at early ages have not been considered in the most of studies. The removal of forms and shores has been dealt with one construction sequence. i.e. the deformation occurred at the early age before the removal of shore has been neglected. In this paper, two-dimensional frame analysis program for long-term behavior of reinforced concrete was developed. In the developed program, construction sequence including the settlement and the removal of shores is considered to predict axial force variation due to forms ,shores, and time-dependent concrete stiffness. Analysis results show that the time-dependent axial force of shores is reduced, and the redistributed axial force of the interior column is greater than the value by elastic analysis and that of the exterior column is smaller. In order to demonstrate the validity of this program, the test frame was constructed in sequence of the placement of concrete, form removal, reshoring, shore removal, and the application of additional load. The proposed program predicts experimental results well.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.3 s.309
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• pp.31-40
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• 2006

Many researches on path planning and obstacle avoidance for the fundamentals of mobile robot have been done. Informations from various sensors can find obstacles and make path. In spite of many solutions of finding optimal path, each can be applied to only a constrained condition. This means that it is difficult to find a universal algorithm. A optimal path with a complicated computation generates a time delay which cannot avoid moving obstacles. In this paper, we propose the algorithm of path planning and obstacle avoidance for mobile robot. We call the proposed method Random Access Sequence(RAS) method. In the proposed method, a small region is set first and numbers are assigned to its neighbors, then the path is selected using these numbers. It has an advantage of fast planning and simple operation. This means that new path selection may be possible within short time and that helps a robot to avoid obstacle in any direction. When a robot meets moving obstacles, it avoids obstacles in a random direction. RAS method using obstacle information from variable sensors is useful to get minimum path length to goal.

• Land and Housing Review
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• v.12 no.3
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• pp.97-108
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• 2021

In bridge abutment structures, lateral squeeze due to lateral stress of embankment placement and thermal movement of the bridge structure leads to failure of approach slabs, girders, and bridge bearings. Recently, GRS (Geosynthetic-Reinforced Soil) integral bridge has been proposed as a new countermeasure. The GRS integral bridge is a combining structure of a GRS retaining wall and an integral abutment bridge. In this study, numerical analyses which considered construction sequences and earthquake loading conditions are performed to compare the behaviors of conventional PSC (Pre-Stressed Concrete) girder bridge, traditional GRS integral bridge structure and GRS integral bridge with bracket structures (newly developed LH-type GRS integral bridge). The analysis results show that the GRS integral bridge with bracket structures is most stable compared with the others in an aspect of stress concentration and deformation on foundation ground including differential settlements between abutment and backfill. Furthermore, the GRS integral bridge with/without bracket structures was found to show the best performance in terms of seismic stability.