• Title/Summary/Keyword: 지각변형

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Horizontal Strain of the Crust in Korea for the Past 80 Years from Geodetic Observations (측지측량 결과로부터 조사된 과거 80년간 한국에서 지각의 수평변형)

  • 최재화
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1997.04a
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    • pp.49-61
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    • 1997
  • 본 연구에서는 한국에서 구삼각강(1910-1915)과 정밀1차측지망(1975-1994)을 사용하여 지각변동량을 계산하고, 지체구조의 일반적인 변형패턴을 기하학적으로 조사하였다. 본 연구에서는 변형량을 계산하기 위하여 2차원의 무한소 변형모델을 설정하였으며, 수평변형량은 구좌표와 정밀1차측지망의 정밀동시강조정을 자유강조정법에 의하여 최초로 실시하여 일괄성있는 신좌표를 사용하여 계산된 측지선의 변화량으로 추정하였다. 변형설계결과로부터 1910년부터 1994년까지 누적된 변형량은 평균(1.07$\pm$0.5)$\times$10-5이고, 이로부터 년변형속도는 (0.13$\pm$0.063)$\mu$/yr 임을 알 수 있었으며, 변형의 경향을 보면 변형량이 10$\mu$ 보다 큰 값이 한반도의 동해안 지역에 분포하고 있으며, 서부쪽에는 10$\mu$이하의 값이 분포하고 있는 것으로 나타나 한반도의 동해안에서 지진의 발생빈도가 높은 것을 고려한다면 본 연구로부터 계산된 결과는 장래의 연구를 위해 중요한 데이터가 될 것이다. 본 연구에서 얻은 주변형축의 방향은 전국적으로 $77.6^{\circ}$$\pm$$13.5^{\circ}$방향임을 보여주고 있어 한반도의 지각은 ENE~WSW방향으로 압축상태에 있음을 알 수 있었으며, 이 결과는 지질학자나 지진학자들의 연구로부터 얻은 결과와 P-축의 방향이 일치하고 있고, 최대전단변형 이론과 일치하고 있는 것으로 나타났다.

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Application of Two Dimensional Filtering Technique for the Precision Calculation of Crustal Deformation Parameters (지각변동 파라메터의 정밀계산을 위한 2차원 필터링 기법의 적용)

  • 윤홍식
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.18 no.1
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    • pp.75-83
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    • 2000
  • This paper deals with the application of two dimensional filtering technique for strain calculation using old and new geodetic data, and discusses the characteristics of general strain pattern in terms of seismic activity and tectonics. The mean rate of maximum shear strain is $0.12{\mu}/yr$. The mean direction of principal axes distribution of the compression is about $N80^{\circ}E$.

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Neotectonic Crustal Deformation and Current Stress Field in the Korean Peninsula and Their Tectonic Implications: A Review (한반도 신기 지각변형과 현생 응력장 그리고 지구조적 의미: 논평)

  • Kim, Min-Cheol;Jung, Soohwan;Yoon, Sangwon;Jeong, Rae-Yoon;Song, Cheol Woo;Son, Moon
    • The Journal of the Petrological Society of Korea
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    • v.25 no.3
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    • pp.169-193
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    • 2016
  • In order to characterize the Neotectonic crustal deformation and current stress field in and around the Korean Peninsula and to interpret their tectonic implications, this paper synthetically analyzes the previous Quaternary fault and focal mechanism solution data and recent geotechnical in-situ stress data and examines the characteristics of crustal deformations and tectonic settings in and around East Asia after the Miocene. Most of the Quaternary fault outcrops in SE Korea occur along major inherited fault zones and show a NS-striking top-to-the-west thrust geometry, indicating that the faults were produced by local reactivation of appropriately oriented preexisting weaknesses under EW-trending pure compressional stress field. The focal mechanism solutions in and around the Korean Peninsula disclose that strike-slip faulting containing some reverse-slip component and reverse-slip faulting are significantly dominant on land and in sea area, respectively. The P-axes are horizontally clustered in ENE-WSW direction, whereas the T-axes are girdle-distributed in NNW direction. The geotechnical in-situ stress data in South Korea also indicate the ENE-trending maximum horizontal stress. The current crustal deformation in the Korean Peninsula is thus characterized by crustal contraction under regional ENE-WSW or E-W compression stress field. Based on the regional stress trajectories in and around East Asia, the current stress regime is interpreted to have resulted from the cooperation of westward shallow subduction of the Pacific Plate and collision of Indian and Eurasian continents, whereas the Philippine Sea plate have not a decisive effect on the stress-regime in the Korean Peninsula due to its high-angle subduction that resulted in dominant crust extension of the back-arc region. It is also interpreted that the Neotectonic crustal deformation and present-day tectonic setting of East Asia commenced with the change of the Pacific Plate motion during 5~3.2 Ma.

Simulation of Human Perception of Similarity between Textures Using Neural Network (신경망을 이용한 사람의 텍스쳐간 유사도 지각의 모의실험)

  • 임도형;정찬섭;이일병
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1998.04a
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    • pp.198-204
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    • 1998
  • 텍스쳐는 그 정의화 특징이 명확하지 않은 패턴이며, 무한한 변형에 따른 무한한 수의 텍스쳐가 존재한다. 이로 인해 사람의 텍스쳐 지각에 관한 연구에 어려움이 있다. 본 논문에서는 신경망으로 사람의 텍스쳐 특징 지각과 텍스쳐간의 유사도 지각을 모의실험하였다. 쌍별비교와 비교판단법칙을 사용하여 사람이 지각하는 텍스쳐의 특징값과 텍스쳐간의 유사도 값을 구하였다. 구한 값을 바탕으로 신경망의 일종인 다층퍼셉트론을 사용하여 특징 추출기와 유사도 특정기를 구현하여 모의 실험하였다. 신경망을 사용하여 모의실험한 결과, 사람의 텍스쳐 특징 지각과 텍스쳐간의 유사도 지각과 유사한 결과를 얻었다. 이러한 실험결과는 신경망으로 구현된 시스템이 사람의 감성적인 수치를 구하는 방법으로 사용될 수 있음을 보여 준다.

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Deformation of Moho in the Southern Part of the Korean Peninsula (한반도 남부 모호면의 변형 구조)

  • Shin, Young-Hong;Park, Jong-Uk;Park, Pil-Ho
    • Journal of the Korean earth science society
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    • v.27 no.6
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    • pp.620-642
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    • 2006
  • The Moho structure and its deformation in the southern part of the Korean Peninsula were estimated using gravity and topography data. Gravity signals from the upper and lower crust were separated using a filter that was computed from isostacy and elastic thickness. The result of this study shows three characteristic features of the Moho deformation. First, the Moho folding structure is parallel to SKTL (the South Korean Tectonic Line), which indicates positive association with the collision of the Yeongnam and Gyeonggi Massifs and repeated compression afterwards. In contrast, noticeable deformation of the Moho was not observed along the Imjingang Belt, which is interpreted as another continental collisional belt in the Korean Peninsula. Second, the Moho beneath the Gyeongsang Basin has remarkably risen; this seems to be the result from both the collisional compression and buoyancy caused by magmatic underplating. Third, the Moho deformation is shallowest in the east of the Taebaek Mountains and deepens toward the west, consistent with the topographic characteristic of the Korean Peninsula of "high east and low west". It can be interpreted as the results of the opening of the East Sea and Ulleung Basin. A tectonic explanation for this could be the ascent of the mantle induced by continental rifting and horizontal extension at the early stage of the opening of the East Sea. The Moho deformation model computed in this study correlates well with the earthquake distribution and crustal movement measured by GPS. We suggest that the compression along the SKTL is still exerted, consequently, the Moho deformation is active, although it may be weak.

The Study for Noisy Speech Improvement with Noise Perception Pattern Suppression (잡음 신호의 지각 패턴 제어를 통한 음질 개선 알고리즘 개발에 관한 연구)

  • Kim Hunjoong;Cha Hyungtai
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.199-202
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    • 2002
  • 본 논문에서는 사람의 청각 모델을 기반으로 잡음에 의해 손상된 음성 신호로부터 잡음 신호의 마스킹 특성과 신호에너지의 지각(知覺)을 나타내는 임계대역(critical band)에서의 잡음 에너지에 대한 지각 패턴인 noise excitation pattern을 이용한 잡음 에너지 차감과 잡음 추정 오차에 의한 변형된 음성신호 내의 순음(tonal) 성분과 비순음(non-tonal)성분의 보정을 통해 효과적인 음성 품질의 개선을 위한 연구를 하였다.

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Characteristics of the Cenozoic crustal deformation in SE Korea and their tectonic implications (한반도 동남부 신생대 지각변형의 주요 특징과 지구조적 의의)

  • Son, Moon;Kim, Jong-Sun;Chong, Hye-Yoon;Lee, Yung-Hee;Kim, In-Soo
    • The Korean Journal of Petroleum Geology
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    • v.13 no.1
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    • pp.1-16
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    • 2007
  • The southeastern Korean Peninsula has experienced crustal multi-deformations according to changes of global tectonic setting during the Cenozoic. Characteristic features of the crustal deformations in relation to major Cenozoic tectonic events are summarized as follows. (1) Collision of Indian and Eurasian continents and abrupt change of movement direction of the Pacific plate (50${\sim}$43 Ma): The collision of Indian and Eurasian continents caused the eastward extrusion of East Asia block as a trench-rollback, and then the movement direction of the Pacific plate was abruptly changed from NNW to WNW. As a result, the strong suction-force along the plate boundary produced a tensional stress field trending EW or WNW-ESE in southeastern Korea, which resultantly induced the passive intrusion of NS or NNE trending mafic dike swarm. (2) Opening of the East Sea (25${\sim}$16 Ma): The NS or NNW-SSE trending opening of the East Sea generated a dextral shear stress regime trending NNW-SSE along the eastern coast line of the Korean Peninsula. As a result, pull-apart basins were developed in right bending and overstepping parts along major dextral strike slip faults trending NNW-SSE in southeastern Korea. The basins can be divided into two types on the basis of geometry and kinematics: Parallelogram-shaped basin (rhombochasm) and wedged-shaped basin (sphenochasm), respectively. In those times, the basins and adjacent basement blocks experienced clockwise rotation and northwestward tilting contemporaneously, and the basins often experienced a kind of propagating rifting from NE toward SE. At about 17Ma, the Yonil Tectonic Line, which is the westernmost border fault of the Miocene crustal deformation in southeastern Korea, began to move as a major dextral strike slip fault. (3) Clockwise rotation of southeastern Japan Island (about 15 Ma): The collision of the Izu-Bonin Arc and southeastern Japan Island, as a result of northward movement of the Philippine sea-plate, induced the clockwise rotation of southeastern Japan Island. The event caused the NW-SE compression in the Korea Strait as a tectonic inversion, which resultantly tenninated the basin extension and caused local counterclockwise rotation of blocks in southeastern Korea. (4) E-W compression in the East Asia (after about 5 Ma): Decreasing subduction angle of the Pacific plate and eastward movement of the Amurian plate have constructed the-top-to-west thrusts and become a major cause for earthquakes in southeastern Korea until the present time.

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