• 제목/요약/키워드: discontinuous

검색결과 1,402건 처리시간 0.036초

The Stress Distribution in a Long Circular Cylinder under a Discontinuous Boundary Conditions on the Curved Surface (곡면상에 불연속경계조건을 간는 원주의 응력분포)

  • Lee, Doo-Sung
    • Transactions of the Korean Society of Mechanical Engineers
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    • 제2권2호
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    • pp.38-41
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    • 1978
  • 이 논문에서는 표면의 일부에 기지의 압력을 밥는 긴 원주내의 응력분포를 구하는 문제를 고찰하였다. 문제를 혼합경계치조건에서 발생되는 쌍적분방정식의 해를 구하는 문제로 간단히 한후에 제 2종 Fredholm 적분방정식을 해결하는 문제로 하였다. 이 적분방정식의 수직해를 전자계산기에 의하여 구한 다음 도시하였다.

Collision prediction and detection in a dynamic environment (동적 환경하에서의 충돌 예측 및 감지)

  • 한인환;양우석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.309-314
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    • 1992
  • Many dynamic mechanical systems, such as parts-feeders, walking machines, and percussive power tools, are described by equations of motion which are discontinuous. The discontinuities result from kinematic constraint changes which are difficult to foresee, especially in presence of impact. A simulation algorithm for these types of systems must be able to algorithmically predict and detect the kinematic constraint changes without any prior knowledge of the system's motion. This paper presents a rule-based approach to the prediction and detection of kinematic constraint changes between bodies with arc and line boundaries. The developed algorithm's ability to accurately and automatically detect the unpredicted changes of kinematic constraints is demonstrated with a numerical example.

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Effect of Tempering Temperatures on Tensile Properties in a Low Carbon Steel (저탄소강에서 템퍼링 온도가 인장변형에 미치는 영향)

  • 이영범;김대성;남원종
    • Transactions of Materials Processing
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    • 제12권8호
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    • pp.744-749
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    • 2003
  • The effect of tempering temperatures on microstructures and mechanical properties was studied in a low carbon steel. The disappearance of continuous yielding and the formation of an extended region in engineering stress-strain curves at tempering temperatures ranging from 673 to 873K was caused by the reduction of mobile dislocations during tempering and dynamic recovery during tensile deformation. In addition, the occurrence of discontinuous yielding in the sample treated at the tempering temperatures above 923K was attributed to the formation of new strain-free polygonal ferrite grain.

Analysis of Crack Localization in Fracture of Concrete Structures (콘크리트 구조물의 파괴에서의 국소화된 균열진행해석)

  • Koo, Ja-Choon;Song, Ha-Won;Shim, Byul;Woo, Seung-Min;Byun, Keun-Joo
    • Proceedings of the Korea Concrete Institute Conference
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    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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    • pp.583-586
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    • 2000
  • In this paper, the embedded crack approach that crack is modeled by discontinuous line inside finite element is applied for localized progressive fracture analyses. The algorithm for progressive fracture analyses of concrete structure are enhanced by introducing nonlinear softening curve and unloading algorithm of tension-softening curve which can simulate localized fracture of concrete. The failure analysis results ar compared with existing test results for varification.

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A study on the analysis of chip flow by the image processing (화상처리를 이용한 칩유동의 해석에 관한 연구)

  • 백인환;이형대
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.811-815
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    • 1990
  • This paper describes the method on image acquisition and image processing in the turning process. The formation of discontinuous chips during high-speed oblique cutting without lubricant was observed by means of video camera recorder and stroboscope. The image processing technique for chip flow is described and the results are presented for variable feeds. It is concluded that experimental values of chip flow angle are similar to theoretical values of Stabler's rule.

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A PETROV-GALERKIN METHOD FOR A SINGULARLY PERTURBED ORDINARY DIFFERENTIAL EQUATION WITH NON-SMOOTH DATA

  • Zheng T.;Liu F.
    • Journal of applied mathematics & informatics
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    • 제22권1_2호
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    • pp.317-329
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    • 2006
  • In this paper, a singularly perturbed ordinary differential equation with non-smooth data is considered. The numerical method is generated by means of a Petrov-Galerkin finite element method with the piecewise-exponential test function and the piecewise-linear trial function. At the discontinuous point of the coefficient, a special technique is used. The method is shown to be first-order accurate and singular perturbation parameter uniform convergence. Finally, numerical results are presented, which are in agreement with theoretical results.

POWER FACTOR CORRECTION OF CO2 WELDING MACHINE USING SINGLE-SWITCH THREE-PHASE AC/DC CONVERTER

  • Kim, Jse-Mun;Kim, Yuen-Chung;Ahn, Jung-Jun;Won, Chung-Yuen;Kim, Sei-Chan
    • Proceedings of the KIPE Conference
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    • 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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    • pp.663-667
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    • 1998
  • This paper describes for reducing harmonic distortion on CO2 welding machine with nonlinear load characteristic using single-switch three-phase AC/DC converter. The low-order harmonic component amplitude of the phase current of single-switch three-phase discontinuous mode is calculated. Experimental results show that CO2 welding machine with single-switch three-phase AC/DC converter is effectively controlled with power factor correction for phase current during welding time.

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Bandwidth Selection for Local Smoothing Jump Detector

  • Park, Dong-Ryeon
    • Communications for Statistical Applications and Methods
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    • 제16권6호
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    • pp.1047-1054
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    • 2009
  • Local smoothing jump detection procedure is a popular method for detecting jump locations and the performance of the jump detector heavily depends on the choice of the bandwidth. However, little work has been done on this issue. In this paper, we propose the bootstrap bandwidth selection method which can be used for any kernel-based or local polynomial-based jump detector. The proposed bandwidth selection method is fully data-adaptive and its performance is evaluated through a simulation study and a real data example.

Range Image Segmentation Based on Polynomial Function Approximation (다항식 함수 근사화에 근거한 거리 영상 분할)

  • 임영수;조택일;박규호
    • Journal of the Korean Institute of Telematics and Electronics
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    • 제27권9호
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    • pp.1448-1455
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    • 1990
  • In this paper, a range image segmentation method is proposed. This method consists of an initial segmentation stage by discontinuous edge detection and surface type labeling based on the sign of the principal curvatures. Initially type labeled image is oversegmented, this image is merged via stepwise optimal region merging stage based on polynomial function approxiamtion. The successful segmentation results are presented for two synthetic range images with noise and a real-world ERIM range image.

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A Study on Excavation Responses of Underground Openings for Radioactive Waste Disposal (굴착으로 인한 방사성폐기물 지하처분공동의 거동변화)

  • 김선훈;김대홍;최규섭;김진웅
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 한국전산구조공학회 1992년도 가을 학술발표회 논문집
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    • pp.174-179
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    • 1992
  • In this paper a discussion is presented about excavation responses of underground openings for radioactive waste disposal. The effects of excavation methods, stress redistribution, thermal change, and backfill materials are reviewed. Comparisons of computational models for discontinuous reek masses and discussions on numerical simulation techniques for the excavation of underground openings are also described. Finally, the application of the CAD system to the planning, design and construction of underground openings fop radioactive waste disposal is introduced.

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