• Title/Summary/Keyword: 대칭축

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Shadow casting method using symmetric and distance feature of the object region (객체의 대칭성과 거리 벡터를 사용한 그림자 제거 방법)

  • Lee JungWon;Choi C.G.;Cho J.H.;Kim SungHo
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.07b
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    • pp.838-840
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    • 2005
  • 본 논문에서는 감시 시스템 내에서 검출된 객체에 대해 정확한 특징벡터를 추출하기 위한 그림자 제거(shadow casting)방법을 제안한다. 그림자에 외해 부정확한 특징벡터를 가지게 되는 객체는 동일한 객체임에도 불구하고 서로 다른 객체로 인식하는 잘못된 결과를 가져온다. 이러한 문제점을 해결하기 위해 객체가 가지는 대칭성을 사용하여 그림자 후보 영역을 추출한 후 중심축으로부터의 거리에 비례한 가중치값을 사용하여, 추출한 영역에 대해 그림자를 제거를 수행한다.

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Rotation of Orthotropy Axes under Plane Stress (평면응력하에서의 직교이방성 대칭축의 회전)

  • 인정제;김권희
    • Transactions of Materials Processing
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    • v.3 no.3
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    • pp.320-334
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    • 1994
  • A set of full size cold rolled steel sheets has been prestrained in the direction of rolling by uniform tensile elongation of 3% and 6%. Then mid-sized tensile specimens were cut from each of the full size sheets at 30, 45, 60 and 90 degrees to the rolling direction. The mid-sized tensile specimens were then prestrained again by uniform tensile elongation by 1%, 2%, 5%, 10% and 15%. finally, miniature tensile specimens were prepared from each of the mid-sized specimens at every 10 degrees to the specimen axis. From the tensile tests on miniature specimens material's hardening behavior under non-proportional loading has been investigated. There are a number of new observations which has not been known to the authors before current work. One of them is continuous reservation of orthoropic symmetry during tensile elongation of mid-sized specimens. Another is continuous rotations of orthotropy axes. Existing theories seem to fail to explain this observations. A new model is proposed in relation to the rotation of orthotropy axes.

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From Landscaping Techniques to Study the Feng Shui Geographical Thought in Chinese Garden (조경기법으로 본 중국원림의 풍수지리사상)

  • Yu, Wen-Dong;Kang, Tai-Ho
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.32 no.3
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    • pp.130-138
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    • 2014
  • This study aimed to grasp Feng Shui Geographical Thought appears in layout, Axial symmetry, hierarchical planning, spatial composition and hidden design techniques of Chinese Garden, that is "Xue effect", "Long-Sha effect" and "Shuikou effect", and to study on expression in Landscape Space. The Author selected the Chinese courtyard and the Nets Garden as the object to prove the Layout landscaping techniques; and selected Beijing in Ming and Qing Dynasties and the Forbidden City, A square design in Xuanwei as the object to prove the Axial Symmetrical and Hierarchical landscaping techniques, and also selected the Lingering G-arden and the Gentle Waves Pavilion, Humble Administrator's Garden in Suzhou, and Nanhu Park in Taian as the object to prove the Spatial Composition and Hidden design techniques. The methods of this article is combined Literature survey and Field survey with Case analysis to draw the conclusions as follows: First, "Xue effect" of Chinese Feng Shui Geographical Thought is suitable for the layout of Chinese courtyard and the Nets Garden in Suzhou; Second, "Long-Sha effect" is suitable for the urban planning of Beijing in Ming and Qing Dynasty, and the layout of the Forbidden City, by the city square design in Xuanwei, we can see that it is also suitable for Chinese modern landscape design; Third, "Shuikou effect" is appeared in the Spatial Composition and Hidden design techniques. All of these landscape design techniques are commonly used in China's modern landscape. It has been proved by the analysis of the Lingering Garden and the Gentle Waves Pavilion, Humble Administrator's Garden in Suzhou, and Nanhu Park in Taian.

Seismic Traveltime Tomography in Inhomogeneous Tilted Transversely Isotropic Media (불균질 횡등방성 매질에서의 탄성파 주시토모그래피)

  • Jeong, Chang-Ho;Suh, Jung-Hee
    • Geophysics and Geophysical Exploration
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    • v.10 no.4
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    • pp.229-240
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    • 2007
  • In this study, seismic anisotropic tomography algorithm was developed for imaging the seismic velocity anisotropy of the subsurface. This algorithm includes several inversion schemes in order to make the inversion process stable and robust. First of all, the set of the inversion parameters is limited to one slowness, two ratios of slowness and one direction of the anisotropy symmetric axis. The ranges of the inversion parameters are localized by the pseudobeta transform to obtain the reasonable inversion results and the inversion constraints are controlled efficiently by ACB(Active Constraint Balancing) method. Especially, the inversion using the Fresnel volume is applied to the anisotropic tomography and it can make the anisotropic tomography more stable than ray tomography as it widens the propagation angle coverage. The algorithm of anisotropic tomography is verified through the numerical experiments. And, it is applied to the real field data measured at limestone region and the results are discussed with the drill log and geological survey data. The anisotropic tomography algorithm will be able to provide the useful tool to evaluate and understand the geological structure of the subsurface more reasonably with the anisotropic characteristics.

Dynamics of a Micro Three-axis Ring Gyroscope Considering Electrode Effects (전극 효과를 고려한 마이크로 3축 링 자이로스코프의 동역학)

  • 김창부;강태민
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.1
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    • pp.64-72
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    • 2004
  • In this paper. we analyse and present electro-mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The motions of the ring are electro-statically derived. sensed and balanced by electrodes. The equations of motion are formulated. The measuring method of angular velocities by force-to-rebalance is presented. The dynamic characteristics of a ring gyroscope are calculated and compared.

Production and Test of a NutationDamper Applied Missile (유도탄에 사용되는 뉴테이션댐퍼의 제작 및 시험)

  • Kim, Sung-Kuk;Lee, Yong-Deog;Yeou, Bo-Yeoun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.159-162
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    • 2007
  • 뉴테이션(Nutation, 장동)은 자이로스코프와 같은 큰 축 대칭 물체의 회전축에 대해 작은 불규칙적인(어원적으로 "nodding") 운동이다. 위성체가 회전상태에 돌입하게 될 때 위성체가 순수한 회전 운동이 아닌 뉴테이션 운동을 일으킬 경우, 이를 제거하기 위하여 뉴테이션댐퍼(NutationDamper)를 사용한다. 유도탄에 들어가는 부품 중에서 자이로조립체 내에 들어 있는 뉴테이션댐퍼의 개발을 하고자 본 연구를 수행 하게 되었으며, 자이로조립체 내에서 뉴테이션댐퍼의 역할은 자이로조립체의 원주상에 환형 튜브 형상으로 장착되어 자이로조립체가 세차운동(Precession)을 할 때 부가적으로 수반되는 바람직하지 못한 떨림(Wobble motion)인 뉴테이션을 감쇠시키는 기능을 수행한다.

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Dynamics of a Micro Three-Axis Ring Gyroscope (마이크로 3축 링 자이로스코프의 동역학)

  • Choi, Sang-Hyun;Kim, Chang-Boo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.37-43
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    • 2002
  • In this paper, we analyse and present mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The equations of motion, the response to angular velocities, and the relationships between the natural modes of vibration are derived and compared with the previous studies for the design of a micro three-axis ring gyroscope.

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Dynamics of a Micro Three-Axis Ring Gyroscope (마이크로 3축 링 자이로스코프의 동역학)

  • Park, Sang-Hyun;Kim, Chang-Boo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.312.1-312
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    • 2002
  • In this paper, we analyse and present mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure rates of turn about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. (omitted)

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Dynamics of a Micro Three-Axis Ring Gyroscope Considering Electrode Effects (전극 효과를 고려한 마이크로 3축 링 자이로스코프의 동역학)

  • 강태민;김창부
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.970-976
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    • 2003
  • In this paper, we analyse and present electro-mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the notation of the gyroscope main body. The motions of the ring are electro-statically derived, sensed and balanced by electrodes. The equations of motion are formulated. The scheme of angular velocities sensing by force-to-rebalance method is presented. The dynamic characteristics of a ring gyroscope are calculated and compared.

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Dynamics of a Micro Three-axis Ring Gyroscope (마이크로 3축 링 자이로스코프의 동역학)

  • Kim, Chang-Boo;Choi, Sang-Hyun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.12
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    • pp.1001-1009
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    • 2002
  • In this paper, we analyse and present mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The equations of motion, the response to angular velocities, and the relationships between the natural modes of vibration are derived and compared with the previous studies for the design of a micro three-axis ring gyroscope.