• Title/Summary/Keyword: Discontinuity point

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Closed-form Green's functions for transversely isotropic bi-solids with a slipping interface

  • Yue, Zhong Qi
    • Structural Engineering and Mechanics
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    • v.4 no.5
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    • pp.469-484
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    • 1996
  • Green's functions are obtained in exact closed-forms for the elastic fields in bi-material elastic solids with slipping interface and differing transversely isotropic properties induced by concentrated point and ring force vectors. For the concentrated point force vector, the Green functions are expressed in terms of elementary harmonic functions. For the concentrated ring force vector, the Green functions are expressed in terms of the complete elliptic integral. Numerical results are presented to illustrate the effect of anisotropic bi-material properties on the transmission of normal contact stress and the discontinuity of lateral displacements at the slipping interface. The closed-form Green's functions are systematically presented in matrix forms which can be easily implemented in numerical schemes such as boundary element methods to solve elastic problems in computational mechanics.

Analysis of Switching Overvoltage in 345kV Underground and Combined Transmission Systems (345kV 지중 및 혼합 송전계통에서의 개폐 과전압 해석)

  • 정채균;이종범;강지원
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.12
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    • pp.713-721
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    • 2003
  • This paper analyzes the switching overvoltage occurred on 345kV underground power cable system as well as combined transmission system using EMTP. Cable length and closing time, preinsertion resistance have effect on switching overvoltage. Therefore, this paper analyzes the switching overvoltage occurred on conductor and sheath with change of those parameters. Specially, the cross bonding position becomes discontinuity point because of the difference between surge impedance of metal sheath and that of lead cable. Thus, the transmission and the reflection of traveling wave complexly occur at this connection point. According to these influences, voltage between sheath and earth as well as voltage between joint boxes rise. Time to crest point of switching overvoltage is longer than lightning overvoltage. Even though the voltage induced by switching surge is smaller than lightning surge, that voltage may have serious effect on the metal sheath. Therefore, this paper also analyses the reduction effect of switching overvoltage when the preinsertion resistance of circuit breaker is considered.

ON THE GIBBS PHENOMENON FOR THE SHANNON SAMPLING SERIES IN WAVELET SUBSPACES AND A WAY TO GO AROUND

  • Shim, Hong-Tae
    • Communications of the Korean Mathematical Society
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    • v.13 no.1
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    • pp.181-193
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    • 1998
  • The Shannon sampling series is the prototype of an interpolating series or sampling series. Also the Shannon wavelet is one of the protypes of wavelets. But the coefficients of the Shannon sampling series are different function values at the point of discontinuity, we analyze the Gibbs phenomenon for the Shannon sampling series. We also find a way to go around this overshoot effect.

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A Study on the Spatial Characteristics in the Tugendhat House (투겐타트 주택의 공간적 특성에 관한 연구)

  • 양재혁;견진현
    • Korean Institute of Interior Design Journal
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    • no.40
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    • pp.42-51
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    • 2003
  • This study aimed at understanding the spatial characteristics in the Tugendhat house. For this study, it is need to analyze the early plans of the Tugendhat house design process. To analyze this, the study leads to how to effect on the real practice with the process. Therefore, this research investigates the conceptional design process of the house. There are 2 main characteristics of the interior space alternation. One is the closed spatial character on the 2nd floor, the other is the open spatial character on the 1st floor. It clearly shows the severance between interior and exterior on the 2nd floor. Each 2nd floor's space volume uses different materials so that each the space can show the individuality. On the 1st floor, however, it seems the interior is not as much open to the exterior, because the materiality and reflection of the glass, the objet of furniture and wall. In case of 1st floor, it has a complex concept as open and close character, because it is using the proper gardening elements and the relationship between the house and site. The exterior characteristic is separated the house from the ground with the podium and the slope, and this leads to have the discontinuity. The house clearly shows the spatial characteristics of the continuity and discontinuity, it proves that Mies tried to move onto modem architecture as a turning point.

Highly Dense 3D Surface Generation Using Multi-image Matching

  • Noh, Myoung-Jong;Cho, Woo-Sug;Bang, Ki-In
    • ETRI Journal
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    • v.34 no.1
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    • pp.87-97
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    • 2012
  • This study presents an automatic matching method for generating a dense, accurate, and discontinuity-preserved digital surface model (DSM) using multiple images acquired by an aerial digital frame camera. The proposed method consists of two main procedures: area-based multi-image matching (AMIM) and stereo-pair epipolar line matching (SELM). AMIM evaluates the sum of the normalized cross correlation of corresponding image points from multiple images to determine the optimal height of an object point. A novel method is introduced for determining the search height range and incremental height, which are necessary for the vertical line locus used in the AMIM. This procedure also includes the means to select the best reference and target images for each strip so that multi-image matching can resolve the common problem over occlusion areas. The SELM extracts densely positioned distinct points along epipolar lines from the multiple images and generates a discontinuity-preserved DSM using geometric and radiometric constraints. The matched points derived by the AMIM are used as anchor points between overlapped images to find conjugate distinct points using epipolar geometry. The performance of the proposed method was evaluated for several different test areas, including urban areas.

Stability Analysis of Toppling Failure in Rock Slopes (암반사면의 전도파괴에 대한 안정해석)

  • 이명재;이인모
    • Geotechnical Engineering
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    • v.14 no.2
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    • pp.55-66
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    • 1998
  • The purpose of this paper is to formulate and apply the stability analysis of toppling failure by considering the variation of discontinuity characteristics, slope geometry, and loading conditions. The stability condition on toppling failure of rock slope is mainly iuluenced by the dip angle $\alpha_B$ and H/t ratio. In order to check toppling failures in design, the stability charts composed of dip angle $\alpha_B$ versus H/t ratio have been constructed in the paper. In general, smaller dip angle $\alpha_B$ and smaller dip angle $\alpha_B$ and smaller H/T ratio give safer condition. The suggested curves change rapidly at the chitical point around the sone, H/t=4~6. The stable zone in stability charles becomes smaller due to step angle $\data$.

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Overlap and Add Sinusoidal Synthesis Method of Speech Signal using Amplitude-weighted Phase Error Function (정현파 크기로 가중치 된 위상 오류 함수를 사용한 음성의 중첩합산 정현파 합성 방법)

  • Park, Jong-Bae;Kim, Gyu-Jin;Hyeok, Jeong-Gyu;Kim, Jong-Hark;Lee, In-Sung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.12C
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    • pp.1149-1155
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    • 2007
  • In this paper, we propose a new overlap and add speech synthesis method which demonstrates improved continuity performance. The proposed method uses a weighted phase error function and minimizes the wave discontinuity of the synthesis signal, rather than the phase discontinuity, to estimate the mid-point phase. Experimental results show that the proposed method improves the continuity between the synthesized signals relative to the existing method.

Mesh Independent 3-D Modeling of Spot Welded Joints using Finite Elements with Embedded Strong Discontinuities (강한 불연속이 내장된 유한요소를 이용한 스폿 용접 접합의 망 독립적 삼차원 모델링)

  • Kim, Jongheon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.4
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    • pp.283-288
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    • 2017
  • A spot welded joint is modeled using 3-D finite elements with embedded strong discontinuities. The spot weld is represented by a special cohesive law on the embedded discontinuity surface, instead of meshing its geometry. This strategy naturally eliminates the need of adaptive FEM meshes fitting the local geometry of the spot weld. Mesh independent solutions are guaranteed by explicitly modeling the detailed shape of the spot weld, which is in contrast with the exiting approach using point constraints for the spot weld.

Gravity Survey on the Subsurface Structure between Waekwan-Pohang in Kyoungsang Basin (중력탐사(重力探査)에 의(依)한 경상층군내(慶尙層群內) 왜관(倭館)-포항간(浦項間)의 지하구조(地下構造) 연구(硏究))

  • Min, Kyung Duck;Chung, Chong Dae
    • Economic and Environmental Geology
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    • v.18 no.4
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    • pp.321-329
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    • 1985
  • The gravity measurement has been conducted at 113 stations with an interval of about 1km along the national road of about 120km running from Busangdong to Pohang through Waekwan, Daegu, Youngchun and Aankang. The subsurface geology and structure along the survey line is interpreted from Bouguer anomaly by applying Fourier method and Talwani method for two dimensional body. The mean depth of Moho discontinuity is 31.4km, and the depth decreases very slowly from inner continent toward east coast. The depth of Conrad discontinuity increases from 11km at the east coastal area to 17km at the inner continental area, and especially increases rapidly in the area between Waekwan to Busangdong. The depth of basement of Kyoungsang Basin inereases from near Waekwan toward Daegu upto about 4. 8km, and increases rapidly to reach the maximum depth of about 8.5km at 8km east of Daegu. But it starts to decrease from the place of 10km west of Youngchun, and is about 7.2km at Youngchun and about 6km at 6km east of Youngchun. The depth starts to increase smoothly beyond this point, and is 7km at 15km east of Youngchun. From this point, the depth starts to decrease again, and is about 3.8km at Ankang. The depth of basement of Pohang Basin is 500m at Pohang and about 650m at 5km west of Pohang. A massive granite body which is considered to be a part of Palgongsan Granite exposed at the depth of 1. 5km at 9km west of Youngchun. Another massive granite body is situated underneath the Pohang Basin at depth of 1.5 to 2km, and sedimentary rocks of Kyoungsang Group and volcanic rocks are distributed between Pohang Basin and this granite body. Finally, Yangsan Fault is identified at about 2.5km east of Ankang.

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Calculation of Key Blocks' Safety Ratio based on Discontinuity Analysis (불연속면 분석에 근거한 쐐기블록 안전율 계산)

  • Kim, Eunsung;Noh, Sanghun;Lee, Sang-Soon
    • Journal of the Korean Geotechnical Society
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    • v.40 no.3
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    • pp.101-108
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    • 2024
  • A system with the ability to recognize potential key blocks during tunnel construction by analyzing the rock face was developed in this study. This system predicts the formation of key blocks in advance and evaluates their safety factors. A laser scanner was used to collect a three-dimensional point cloud of the rock face, which was then utilized to model the excavation surface and derive the joint surfaces. Because joint surfaces have specific strikes and dip angles, the key blocks formed by these surfaces are deduced through iterative calculations, and the safety factor of each key block can be calculated accordingly. The model experiments confirmed the accuracy of the system's output in terms of the joint surface characteristics. By inputting the joint surface information, the calculated safety factors were compared with those from the existing commercial software, demonstrating stable calculation results within a 1% error margin.