• Title/Summary/Keyword: rift

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Geology of the Hawaii Island and Volcanic Activities of Mauna Loa and Kilauea (하와이 섬의 지질과 마우나로아 및 킬라우에아의 화산활동)

  • 황상구;이문원;원종관;우경식;이광춘
    • The Journal of the Petrological Society of Korea
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    • v.12 no.4
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    • pp.184-195
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    • 2003
  • Hawaii Island makes up of five volcanos of Kohala, Mauna Kea, Hualalai, Mauna Loa, and Kilauea. They are big shield volcanoes rising above the Pacific ocean floor and final two volcanoes provide a natural laboratory for the study of active volcanoes. Mauna Loa is the largest single volcano on earth. At the submmit is an oval-shaped Mokuaweoweo caldera, from which two rift zones extend to the southwest and northeast, and in the medial part are the longest lava tube systems in the world. Kilauea has been formed largely by eruption along southwest and eastern rift zones extending from Kilauea caldera at the submmit. On the eastern rift zone, spectacularly, the 1989-1974 eruption of Kilauea at Mauna Ulu crater formed the Mauna Ulu lava flow field. The 1983-1986 eruption of aa flows at Puu Oo crater, and the activities of pahoehoe flows during 1986-1990 at Kupaianaha crater and during 1991-recent at the Puu Oo has produced the Puu Oo and Kupaianaha lava flow field.

Study for Operation Teaching Machine Using 3D Virtual Reality System (3D가상 현실방식을 사용한 수술교육시스템의 연구)

  • Kang, Byung-Hoon;Kim, Ji-Sook;Kim, Han-Woong
    • Journal of Digital Contents Society
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    • v.17 no.4
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    • pp.287-293
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    • 2016
  • Some studies require sufficient amount of time, spaces, and financial condition for practical exercises and training. In particular for the Medical education, time and space limitation is very high and difficulties occurs, since the practices are done with cadavers (deceased human body). Many alternate 3D Virtual surgery training system exist currently, however the burdensome of obtaining those costly equipments is problematic. Providing the surgical environment as similar to real as possible using 3D Virtual Reality can be a solution to current problems. The effectiveness of training could be maximized with minimized costs without the general interfaces such as keyboard and mouse, but with Oculus Rift and Leap Motion. This paper will develop and practice the 3D Virtual Operation System with two devices to investigate the possibility and expand to other Simulation fields.

Characteristics of the Rock Cleavage in Jurassic Granite, Pocheon (포천지역의 쥬라기 화강암에 발달된 결의 특성)

  • 박덕원;김형찬;이창범;장세원;이철우
    • The Journal of the Petrological Society of Korea
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    • v.13 no.3
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    • pp.133-141
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    • 2004
  • We have studied the characteristics of rock cleavage for the Pocheon granite with Jurassic emplacement age. Photomicrographs were used to observe and analyze microcracks from the granite. Three sets of microcrack planes are recognized; (1) the rift plane developed parallel to the principal sets of microcracks, (2) the grain plane parallel to the secondary sets of microcracks, (3) the hardway plane perpendicular to both rift and grain planes. The microcracks developed in the granite shows higher polution, mean length and density in the order of rift plane, grain plane and hardway plane. The fracturing characteristics of the granite are closely related to the development of these three planes.

Structural, Paleomagnetic and Petrological Studies of the Chugaryeong Rift Valley (추가령(標哥嶺) 지구대(地構帶)의 지질구조(地質構造), 고지자기(古地磁氣) 및 암석학적(岩石學的) 연구(硏究))

  • Kim, Kyu Han;Kim, Ok Joon;Min, Kyung Duck;Lee, Youn Soo
    • Economic and Environmental Geology
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    • v.17 no.3
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    • pp.215-230
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    • 1984
  • Petrological, paleomagnetic, geomorphological and structural studies on the southern part of, so called, Chugaryeong rift valley, have been carried out in order to clarify the nature of the rift valley. Three stages of volcanic activities characterized by Jijangbong acidic volcanic rocks and tholeiitic and andesitic basalt of Cretaceous age(?), and Jongok Quaternary olivine basalt occurred along the Dongducheon fault line. Jijangbong acidic volcanic rocks distributed in the central part of the studied area consist of rhyodacite, acidic tuff and tuff breccia, which are bounded by Dongsong fault on the east and Daegwangri fault on the west. The Jongok basalt differs from those of Ulrung and Jeju islands in mineralogy, chemical composition and differentiation. Jongok basalt distributed along the Hantan river dilineates the vesicles curved toward downstream direction and increment of numbers and thickness of lava flow toward upstream direction. These facts suggest that lava flowed from upstream side of the river. Rectangular drainage patterns also support the presence of the Dongducheon, Pocheon, Wangsukcheon and Kyonggang faults which were previously known. LANDSAT image, however, does not show any lineaments which could be counted as a graben or rift valley. Displacement of Precambrian quartzite and Jurassic Daedong supergroup along the southwestern extension of the Dongducheon fault shows the right lateral movement. The Paleomagnetic study of the tholeiitic and andesitic basalts from Baegeuri, Jangtanri and Tonghyeonri located at 2. 3km east, 0km east, and 1.5km west of Dongducheon fault respectively shows that their VGP(Virtual Geomagnetic Pole) being to intermediate geomagnetic field of short duration which suggests that they formed in almost same period. Mean VGP of Jongok basalt is located 82.4N and 80.6E. This is in good coincidence with worldwide VGP of Plio-Pleistocene indicating that Jongok basalt was extruded during Plio-Pleistocene epoch, and suggesting that the studied area has been tectonically stable since then. From the present study, the tectonic episode of the region is concluded as following three stages. 1. The 1st period is worked by the Daebo orogeny of Jurassic during which granodiorite was intruded in Precambrian basement. 2. The 2nd period is the time when right lateral strike-slip fault of NNE-SSW direction was formed probably during late Cretaceous to Paleogene and the Jijangbong acidic volcanic rocks and the older basalts were extruded. 3. The 3rd period is the time when the fault was rejuvenated during Pliocene or Pleistocene accompanied by the eruption of Jongok basalt. As a conclusion, geologic structure of the studied area is rather fault line valley than graben or rift valley, which is formed by differential erosion along the Dongducheon fault suggesting a continuation of the Sikhote-Alin fault. The volcanic rocks including the Jijangbong acidic rocks, tholeiitic-andesitic basalt and olivine basalt are associated with this fault line.

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Estimation of Micro-discontinuity Distribution Using Scanline Survey in Granites (조사선을 이용한 화강암의 미세 불연속면 분포성상 평가)

  • 이상은;조상호;양형식;박홍민
    • Tunnel and Underground Space
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    • v.9 no.4
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    • pp.364-372
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    • 1999
  • In this paper, mechanical characteristics of micro-defects in granitic rock was studied. Crack spacing and length were investigated by scanline survey in specimen of granite. To estimate the direction and distribution of potential microcrack in granite, thin sections were made for three direction of Rift, Grain and Hardway axis of the rock specimen. The density and length of microcrack were investigated quantitatively. Three directions of microcracks are comparatively perpendicular. Crack density varies as direction differs, but crack length doesn't show influence of direction.

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The Size Effect in Measuring the Fracture Toughness of Rock using Chevron Bend Specimen (암석의 파괴인성 측정에서 나타나는 CB 시험편의 치수효과에 관하여)

  • 김재동;백승규
    • Tunnel and Underground Space
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    • v.2 no.2
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    • pp.251-264
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    • 1992
  • In this study, the size effect in measuring the fracture toughness of rock was investigated using the ISRM Suggested Method for Fracture toughness using Chevron Bend Specimens. Total 58 specimens were prepared with 4 different diameters, 29, 42, 54, 68mm and center cut-chevron notch. In addition to this, to evaluated the effect of anisotropy of Jecheon granite, which is the sample for this study, core drilling direction was adjusted perpendicular(short transverse) and parallel(arrester) to the rift plane in the sample and the measured fracture toughness for each direction were compared. Important results obtained from this study are as follows. Level ll test condition is more adequate than l, because of low data scattering and precision and corrected fracture toughness of Jechoen granite measured and 2.2MPa{{{{ SQRT { m} }}}} for arrester direction with minimum initial crack length 0.7cm. From the relationship between core diameter and initial crack length presented in the ISRM testing method, the specimen diameter should be bigger than 47mm. The fracture toughnesses measured for arrester and short transverse directon show 10% difference. This is to the anisotropy of Jecheon granite possessing rift plane.

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Cases of Design and Implementation of Sports using Virtual Reality (가상현실을 이용한 스포츠 설계 및 구현 사례)

  • Jin, Hwa-Soo;Park, Jin-Gon;LEE, Yong-Hee;Song, Eun-Jee
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.10a
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    • pp.661-662
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    • 2017
  • 가상현실(VR)은 현실 세계를 인공적인 기술을 활용하여 실제로 얻기 힘든 경험이나 환경 등을 제공해 인체의 오감(시각, 청각, 후각, 미각, 촉각)을 자극함으로써 실제와 같이 체험하게 하는 기술로써 게임, 영화, 스포츠, 테마파크와 같이 엔터테인먼트 목적으로 개발되는 경우가 많다. 본 논문에서는 Oculus Touch 및 Oculus Rift를 이용한 VR(Virtual Reality) 올림픽 종목의 스포츠를 설계하고 구현한 시스템을 제안한다. 올림픽 종목 중에 인기종목인 양궁, 사격, 테니스, 탁구 총 4가지 종목으로 구성되어 있으며, 특히 AI를 이용한 경쟁을 통해 종목별 스코어(점수)를 평가함으로서 경쟁구도를 형성한다. 또한, 시각적인 자극을 통해 흥미를 이끌어내고 현실적인 환경을 구현함으로써 유저가 실제 현장에 있는 것 같은 느낌을 제공하며, 세계적인 올림픽 스포츠를 유저들이 직접 즐기고 느낄 수 있다.

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Evaluation for Rock Cleavage Using Distribution of Microcrack Spacings (II) (미세균열의 간격 분포를 이용한 결의 평가(II))

  • Park, Deok-Won
    • The Journal of the Petrological Society of Korea
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    • v.25 no.2
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    • pp.151-163
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    • 2016
  • The characteristics of the rock cleavage in Jurassic granite from Geochang were analysed. The evaluation for the three directions of rock cleavages was performed using the parameters such as (1) frequency of microcrack spacing(N), (2) total spacing(${\leq}1mm$), (3) mean spacing($S_{mean}$), (4) difference value($S_{mean}-S_{median}$) between mean spacing($S_{mean}$) and median spacing($S_{median}$), (5) density of spacing(${\rho}$), (6) difference value between two exponents for the whole range of the diagrams(${\lambda}_H-{\lambda}_L$), (7) mean value of exponent(${\lambda}_M$), (8) mean value of exponential constant($a_M$), (9) difference value between two exponents for the section under the initial points of intersection(${\lambda}t_H-{\lambda}t_L$), (10) mean value of exponent(${\lambda}t_M$) and (11) mean value of exponential constant($at_M$). The results of correlation analysis between the values of parameters for three rock cleavages and those for three planes are as follows. The values of (I) parameters(1, 2, 7 and 8) and (II) parameters(3, 4 and 5) are in orders of (I) H(hardway, (H1 + H2)/2) < G(grain, (G1 + G2)/2) < R(rift, (R1 + R2)/2) and (II) R < G < H. On the contrary, the values of the above two groups(I~II) of parameters for three planes show reverse orders. Besides, the values of parameter $6({\lambda}_H-{\lambda}_L)$, parameter $9({\lambda}t_H-{\lambda}t_L)$, parameter $10({\lambda}t_M)$ and parameter $11(at_M)$ for three planes are in orders of R(rift plane, (G1 + H2)/2) < H(hardway plane, (R2 + G2)/2) < G(grain plane, (R1 + H2)/2), H < G < R, H < R < G and R < H < G, respectively. The values of the above four parameters for three rock cleavages show the various orders of R < H < G, R < H < G, H < G < R and H < G < R, respectively. Meanwhile, the spacing values equivalent to the initial points of contact and intersection between the two directions of diagrams were derived. The above spacing values for three rock cleavages are in order of rift(R1 and R2) < grain(G1 and G2) < hardway(H1 and H2). The spacing values for three planes are in order of rift plane(G1 and H1) < hardway plane(R2 and G2) < grain plane(R1 and H2). In particular, the intersection angles for three rock cleavages and three planes are in order of rift and rift plane < hardway and hardway plane < grain and grain plane. Consequently, the two diagrams of rift(R1 and R2) and rift plane(G1 and H1) show higher frequency of the point of contact and intersection. These characteristics of change were derived through the general chart for three planes and three rock cleavages. Lastly, the correlation analysis through the values of parameters along with the distribution pattern is useful for discriminating three quarrying planes.