• 제목/요약/키워드: difference matrix

검색결과 963건 처리시간 0.032초

Numerical study on the effect of crack network representation on water content in cracked soil

  • Krisnanto, Sugeng;Rahardjo, Harianto;Leong, Eng Choon
    • Geomechanics and Engineering
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    • 제21권6호
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    • pp.537-549
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    • 2020
  • The presence of cracks changes the water content pattern during seepage through a cracked soil as compared to that of intact soil. In addition, several different crack networks may form in one soil type. These two factors result in a variation of water contents in the soil matrix part of a cracked soil during seepage. This paper presents an investigation of the effect of crack network representation on the water content of the soil matrix part of cracked soil using numerical models. A new method for the numerical generation of crack networks incorporating connections among crack endpoints was developed as part of the investigation. Numerical analysis results indicated that the difference in the point water content was large, whereas the difference in the average water content was relatively small, indicating the uniqueness of the crack network representation on the average water content of the soil matrix part of cracked soil.

A NOTE ON DIFFERENCE SEQUENCES

  • Park, Jin-Woo
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제16권3호
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    • pp.255-258
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    • 2009
  • It is well known that for a sequence a = ($a_0,\;a_1$,...) the general term of the dual sequence of a is $a_n\;=\;c_0\;^n_0\;+\;c_1\;^n_1\;+\;...\;+\;c_n\;^n_n$, where c = ($c_0,...c_n$ is the dual sequence of a. In this paper, we find the general term of the sequence ($c_0,\;c_1$,... ) and give another method for finding the inverse matrix of the Pascal matrix. And we find a simple proof of the fact that if the general term of a sequence a = ($a_0,\;a_1$,... ) is a polynomial of degree p in n, then ${\Delta}^{p+1}a\;=\;0$.

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모델기반의 계측데이터 확장 및 손상 추정에 관한 연구 (A Model-based Study on the Expansion of Measured Data and the Damage Detection)

  • 강택선;이병헌;은희창
    • 대한건축학회논문집:구조계
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    • 제34권3호
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    • pp.3-10
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    • 2018
  • It's not practical to collect all information at the entire degrees of freedom of finite element model. The incomplete measurements should be expanded for subsequent analysis and damage detection. This work presents the analytical methods to expand the incomplete static or dynamic response data. Using the expanded data, introducing the concept of residual force, and minimizing the performance index expressed as the stiffness matrix and its difference before and after damage, the variation in stiffness matrix is derived. Based on the difference in the stiffness matrix, the damage detection method of structures is also provided. The validity of the proposed methods is illustrated in a numerical application, the numerical results are analyzed for applications, and the applicability of both methods is investigated.

곡선보 요소의 고유치 해석에서 질량행렬의 영향 (The Effect of the Mass Matrix in the Eigenvalue Analysis of Curved Beam Elements)

  • 유하상
    • 대한기계학회논문집A
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    • 제21권2호
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    • pp.288-296
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    • 1997
  • Curved beam elements with two nodes based on shallow beam geometry and strain interpolations are employed in eigenvalue analysis. In these elements, the displacement interpolation functions and mass matrices are consistent with strain fields. To assess the quality of the element mass matrix in free vibration problems, several numerical experiments are performed. In these analysis, both the inconsistent mass matrices using linear displacement interpolation function and the consistent mass matrices are used to show the difference. The numerical results demonstrate that the accuracy is closely related to the property of the mass matrix as well as that of the stiffness matrix and that the mass matrix consistent with strain fields is very beneficial to eigenvalue analysis. Also, it is proved that the strain based elements are very efficient in a wide range of element aspect ratios and curvature properties.

고크롬 철계 오버레이용접층의 긁힘마모거동에 미치는 기지상의 영향 (Effect of Matrix Phase on the Abrasive Wear Behavior of the High Cr White Iron Hardfacing Weld Deposites)

  • 백응률
    • Journal of Welding and Joining
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    • 제16권1호
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    • pp.114-124
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    • 1998
  • The effect of matrix phase (austenite, pearlite, martensite) on the low stress abrasion resistance in the chromium-carbide-type high Cr white iorn hardfacing weld deposites has been investigated. In order to examine matrix phase, a series of alloys with different matrix phase by changing the ratio of Cr/C system by heat treatment were employed. The alloys were deposited twice on a mild steel plate using self-shielding flux cored arc welding process. The low stress abrasion resistance of the alloys against sands was measured by the Dry Sand/Rubber Wheel Abrasion Test(RWAT). Even though formation of pearlite phase in the matrix showed higher hardness than that of austenite, there was no observable difference in wear resistance between the pearlite and austenite phase for the same amount of chromium-carbide in the matrix. On the other hand, the formation of martensitic phase,, from heat treated austenitic alloys (high content of Cr), enhanced wear resistance due to its fine secondary precipitates.

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연속 블록간의 화소차이 행렬을 이용한 워터마크 알고리즘 (Watermark Algorithm Using Difference Matrix between Successive Blocks)

  • 박기홍;김윤호
    • 한국항행학회논문지
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    • 제12권3호
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    • pp.273-279
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    • 2008
  • 본 논문에서는 웨이블릿 기반 화소차이 행렬을 이용한 워터마킹 알고리즘을 제안하였다. 전처리과정으로 1-레벨 웨이블릿 변환을 수행한 후, 저주파 대역을 제외한 고주파 대역부분의 계수 블럭을 정규화하여 웨이블릿역변환을 거쳐 참조 영상을 만든다. 원 영상과 참조 영상의 인접블럭에 대한 분산을 계산하고 고주파 성분이 원 영상에 미치는 지역적 특성을 고려하여 워터마크를 삽입한다. 실험결과, 제안한 방법이 비가시성이 우수하고 외부공격(잡음첨가, 필터링, JPEG)의 영상처리에 강인함을 확인하였다.

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