• 제목/요약/키워드: contour integration

검색결과 37건 처리시간 0.021초

Thermographic Detection of Surface Crack Using Holomorphic Function of Thermal Field

  • Kim, No-Hyu;Lim, Zong-Soo
    • 비파괴검사학회지
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    • 제32권3호
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    • pp.296-301
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    • 2012
  • This paper describes an analytic method for infrared thermography to detect surface cracks in thin plates. Traditional thermographic method uses the spatial contrast of a thermal field, which is often corrupted by noise in the experiment induced mainly by emissivity variations of target surfaces. This study developed a robust analytic approach to crack detection for thermography using the holomorphic function of a temperature field in thin plate under steady-state thermal conditions. The holomorphic function of a simple temperature field was derived for 2-D heat flow in the plate from Cauchy-Riemann conditions, and applied to define a contour integral that varies depending on the existence and strength of singularity in the domain of integration. It was found that the contour integral at each point of thermal image reduced the noise and temperature variation due to heat conduction, so that it provided a clearer image of the singularity such as cracks.

PARAMETRIC EULER SUMS OF HARMONIC NUMBERS

  • Junjie Quan;Xiyu Wang;Xiaoxue Wei;Ce Xu
    • 대한수학회보
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    • 제61권4호
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    • pp.1033-1051
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    • 2024
  • In this paper, we define a parametric variant of generalized Euler sums and construct contour integration to give some explicit evaluations of these parametric Euler sums. In particular, we establish several explicit formulas of (Hurwitz) zeta functions, linear and quadratic parametric Euler sums. Furthermore, we also give an explicit evaluation of alternating double zeta values ${\zeta}({\bar{2j}};\,2m+1)$ in terms of a combination of alternating Riemann zeta values by using the parametric Euler sums.

광속전달법에서의 효율적인 Form Factor 계산방법에 관한 연구 (The Study on form Factor Computation Methods in the Luminous Flux Transfer Method)

  • 최안섭
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2001년도 학술대회논문집
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    • pp.17-22
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    • 2001
  • This paper gave a review of form factor computations in the luminous flux transfer method and practical application of DiLaura's recently developed form factor computation. A systematic analysis of how the results of a contour integration solution differ from those of existing numeric solutions were undertaken with a developed computer simulation program. Various situations between sending and receiving surfaces were considered, including the facing, size, and distance between surfaces.

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On the Numerical Evaluation of the Wave Patten of a Havelock Source

  • Dong-Kee,Lee
    • 대한조선학회지
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    • 제16권4호
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    • pp.13-21
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    • 1979
  • A method of evaluating Kelvin wave pattern is presented in this paper. The mathematical manipulation of x-derivative of the Green function of the Havelock source by the use of contour integration on the complex plane has resulted in the expression that can be readily incorporated with computer program. The efficiency and accuracy that can be secured by the use of the present mathematical expressions seem to be excellent when suitable numerical quadratures are employed. The wave patterns for particular submergences of the singularity are presented.

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A Green's-Matrix Approach to Chemisorption

  • Jang, Yun-Hee;Kim, Ho-Jing
    • Bulletin of the Korean Chemical Society
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    • 제14권2호
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    • pp.238-243
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    • 1993
  • A self-consistent-field Green's matrix method for the calculation of electronic properties of chemisorbed system is devised and applied to the methanol on copper(110) surface. The method is based on CNDO Hartree-Fock approximation. Contour integration in the complex energy plane is used for an efficient calculation of the charge-density bond-order matrix. The information on each fragment prior to chemisorption is efficiently used and a small number of iterations are needed to reach the self-consistency. The changes of density of states and other quantities of methanol due to chemisorption are consistent with reported experimental results.

상악전치부임플란트에서의 즉시식립 후 심미수복증례 (Case Report; Esthetic Restorations for Immediate Implantation and Delayed loading on Maxillary Anterior Region)

  • 이희경
    • 대한치과의사협회지
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    • 제55권10호
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    • pp.733-737
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    • 2017
  • Successful osseo-integration of dental implants that Dr. Bronemak reported in 1965 had been ground-breaking research in the restorative dentistry for the missing dentition. Clinical application of dental implants in the restorative dentistry has begun with the role of retention and support for the complete denture, beyond the functional recovery in partially missing area, and succeeds in the cosmetic recovery for anterior missing area. Recently, immediate implantation and loading after the extraction have been preferred by many excellent clinicians especially on maxillary anterior missing area, because they want to prevent from the absorption of residual alveolar bone. But it is hard to decide immediate loading for common clinicians also, because it is difficult for them to convict proper osseo-integration. In this article, immediate implantation and delayed loading case on maxillay anterior region have been introduced and predictable prosthetic procedure for the esthetic result has suggested.

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The future role of smart structure systems in modern aircraft

  • Becker, J.;Luber, W.;Simpson, J.;Dittrich, K.
    • Smart Structures and Systems
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    • 제1권2호
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    • pp.159-184
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    • 2005
  • The paper intends to summarize some guidelines for future smart structure system application in military aircraft. This preview of system integration is based upon a review on approximately one and a half decades of application oriented aerospace related smart structures research. Achievements in the area of structural health monitoring, adaptive shape, adaptive load bearing devices and active vibration control have been reached, potentials have been identified, several feasibility studies have been performed and some smart technologies have been already implemented. However the realization of anticipated visions and previously initial timescales announced have been rather too optimistic. The current development shall be based on a more realistic basis including more emphasis on fundamental aircraft strength, stiffness, static and dynamic load and stability requirements of aircraft and interdisciplinary integration requirements and improvements of integrated actors, actuator systems and control systems including micro controllers.

$J_k$ 적분을 이용한 이방성 복합적층판에 대한 혼합 모우드 파괴문제의 해석 (Analysis of mixed mode crack problems for anisotropic composite laminates using the $J_k$ integral)

  • 주석재;홍창선
    • 대한기계학회논문집
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    • 제13권3호
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    • pp.479-489
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    • 1989
  • 본 논문에서는 J$_{1}$,J$_{2}$ 적분과 K$_{I}$,K$_{II}$ 사이의 완전한 관계를 좁은 직사각형 경로를 택하여 간판하게 유도하였다. 그리고 유한요소의 해로 J$_{2}$적분을 효율적으로 계산하는 방법을 제시하였다.이미 해가 존재하는 문제 를 본 방법으로 다루어 그 결과를 비교하였고 일방향(unidirectional) 적층판 cantil- ever 평판 내의 single edge crack에 대한 해를 제시하였다.

다중세포로 구성된 박벽 타원형 단면 복합재료 블레이드의 구조해석 (Structural Analysis of Thin-Walled, Multi-Celled Composite Blades with Elliptic Cross-Sections)

  • 박일주;정성남
    • Composites Research
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    • 제17권4호
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    • pp.25-31
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    • 2004
  • 본 연구에서는 다중세포로 구성된 타원형 단면 복합재료 블레이드의 정밀 1차원 보 해석모델을 개발하였다. 보의 정식화를 위하여 Reissner의 반보족에너지 함수를 이용하였으며, 고전적인 강성도 및 유연도법을 결합한 혼합보 이론 체계를 구축하였다. 타원단면의 특성계수들을 구하기 위해 단면의 외곽선을 유한개의 선분으로 분할하고 여기에 Gauss 적분을 수행하였다. 또한, 단면을 구성하는 각 세포에 대해 4개의 연속방정식이 충족되도록 구성하였다. 개발된 보 이론을 단일 및 이중세포로 구성된 타원형 복합재료 블레이드에 적용하였으며, 다차원 정밀 유한요소 해석 결과와 비교하여 그 타당성을 확보하였다.