• Title/Summary/Keyword: Relaxation Method

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Fuzzy Relaxation Based on the Theory of Possibility and FAM

  • Uam, Tae-Uk;Park, Yang-Woo;Ha, Yeong-Ho
    • Journal of Electrical Engineering and information Science
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    • 제2권5호
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    • pp.72-78
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    • 1997
  • This paper presents a fuzzy relaxation algorithm, which is based on the possibility and FAM instead of he probability and compatibility coefficients used in most of existing probabilistic relaxation algorithms, Because of eliminating stages for estimating of compatibility coefficients and normalization of the probability estimates, the proposed fuzzy relaxation algorithms increases the parallelism and has a simple iteration scheme. The construction of fuzzy relaxation scheme consists of the following three tasks: (1) definition of in/output linguistic variables, their term sets, and possibility. (2) Definition of FAM rule bases for relaxation using fuzzy compound relations. (3) Construction of the iteration scheme for calculating the new possibility estimate. Applications to region segmentation an ege detectiojn algorithms show that he proposed method can be used for not only reducing the image ambiguity and segmentation errors, but also enhancing the raw edge iteratively.

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A Study on Spin-Lattice Relaxation of Methyl Protons in 2,6-Dichlorotoluene and N-Methyl Phthalimide

  • Lee, Jo-Woong;Lim, Man-Ho;Rho, Jung-Rae
    • Bulletin of the Korean Chemical Society
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    • 제12권1호
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    • pp.47-51
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    • 1991
  • Spin-lattice relaxation of methyl protons in 2,6-dichlorotoluene and N-methyl phthalimide, each dissolved in CDCl$_3$, has been studied at 34$^{\circ}$C and the contribution from spin-rotation interaction to the relaxation process has been separated from that due to dipole-dipole interactions among methyl protons. The results show that the spin-rotational contributions to the initial rate of relaxation in 2,6-dichlorotoluene and N-methyl phthalimide amount to 18 and 31%, respectively, of the total relaxation rate at 34$^{\circ}$C. The method of separating the spin-rotational contribution from that of dipolar interactions adopted in this paper is based on the well known fact that in an A$_3$ spin system such as methyl protons in liquid phase dipolar relaxation mechanism gives non-exponential decay of the z-component of total magnetization of protons while the random field fluctuation such as spin-rotational mechanism causes exponential decay.

암반층에서 쉴드 TBM 터널 세그먼트의 작용하중 산정방법에 관한 연구 (A Study on Earth Pressure Calculating Method about Shield TBM Tunnel Segments in the Rock)

  • 천병식;기정서;강태희;곽윤형;변요셉
    • 한국지반환경공학회 논문집
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    • 제15권5호
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    • pp.13-21
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    • 2014
  • 본 연구에서는 쉴드 TBM 공법의 다양한 세그먼트 모델링 기법에 따른 비교 해석을 통하여 해석기법에 따른 차이를 분석하고 이에 따른 합리적인 모델링 기법을 제안하였다. 또한 암반 이완하중 산정모델에 따른 하중 분석 및 3차원 유한요소해석을 통하여 실제 현장에서 적용 가능한 합리적인 하중산정 방법을 제시하였다. 암반분류에 의한 이완영역의 산정방법은 암반등급이 높은 지반에서는 결과의 차이가 크지 않으나 지반등급이 낮은 지반에서는 그 차이가 매우 크게 나타났으며, 3차원 해석에 의한 이완영역 산정결과 지반등급이 낮은 지반의 이완영역은 각 방법의 중간 정도 범위에 위치할 것으로 예측되었으며 지반등급이 낮은 지반의 세그먼트 계획 시에는 기계식 터널 굴착 특성을 반영한 3차원 해석을 통한 이완영역의 산정을 적극 검토할 필요가 있다.

이완법을 이용한 SWASH 모형의 파랑 조파기법 개선 (Improvement of Wave Generation for SWASH Model Using Relaxation Method)

  • 신충훈;윤성범
    • 한국해안·해양공학회논문집
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    • 제29권4호
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    • pp.169-179
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    • 2017
  • 본 연구에서는 선형 및 비선형파의 안정적이고 정확한 조파를 위해 이완법을 이용한 조파기법을 비정수압 수치모형인 SWASH 모형에 적용하였다. 이완법을 이용한 조파기법을 검증하기 위해 선형파와 비선형파인 경우에 대해 수치실험을 수행하였고 해석해와 비교하였다. 그 결과 Stokes 파 영역으로부터 cnoidal 파 영역에 이르는 모든 경우의 입사파랑이 성공적으로 생성되고 전파되었다. 또한 파고와 파형이 해석해와 잘 일치하는 것을 확인할 수 있었다.

동적이완법을 이용한 Steel Lazy Wave Riser의 정적형상 추정에 관한 수치해석적 연구 (Numerical Study on Estimation of Static Configuration of Steel Lazy Wave Riser Using Dynamic Relaxation Method)

  • 오승훈;정재환;박병원;권용주;정동호
    • 한국해양공학회지
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    • 제32권6호
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    • pp.466-473
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    • 2018
  • This paper presents an estimation method for the static configuration of a steel lazy wave riser (SLWR) using the dynamic relaxation method applied to estimate the configuration of structures with strong geometric non-linearity. The lumped mass model is introduced to reflect the flexible structural characteristics of the riser. In the lumped mass model, the tensions, shear forces, buoyancy, self-weights, and seabed reaction forces at nodal points are considered in order to find the static configuration of the SLWR. The dynamic relaxation method using a viscous damping formulation is applied to the static configuration analysis. Fictitious masses are defined at nodal points using the sum of the largest direct stiffness values of nodal points to ensure the numerical stability. Various case studies were performed according to the bending stiffness and size of the buoyancy module using the dynamic relaxation method. OrcaFlex was employed to validate the accuracy of the developed numerical method.

REM 모델에 의한 Poly(methyl acrylate)-Poly(acrylonitrile) 공중합체 완화스펙트럼의 pH 영향 (pH Effect on Relaxation Spectra of Poly(methyl acrylate)-Poly(acrylonitrile) Copolymers by REM Model)

  • 김남정
    • 폴리머
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    • 제37권2호
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    • pp.135-140
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    • 2013
  • Poly(methyl acrylate)-poly(acrylonitrile) 공중합체의 응력완화 실험은 용매기를 부착한 인장 시험기를 사용하여 여러 온도의 공기 중, 증류수, pH 3, 7, 11 용액에서 실행하였다. Ree-Eyring and Maxwell 모델로부터 얻은 완화스펙트럼 식에 실험적인 응력완화 곡선을 대입하여 poly(methyl acrylate)-poly(acrylonitrile) 공중합체의 완화스펙트럼을 얻었다. 완화스펙트럼의 계산은 Laplace 변환법을 사용한 컴퓨터 프로그램을 이용하였다. 이들 시료의 완화스펙트럼은 유동단위의 분자량과 자체확산 분포와 밀접한 관계가 있음을 알 수 있었다.

근이완요법이 교통사고 환자의 스트레스와 불안에 미치는 영향 (Effect of Progressive Muscle Relaxation Therapy on Stress and Anxiety of Patients from Traffic Accidents)

  • 최운주;은영
    • 근관절건강학회지
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    • 제17권2호
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    • pp.132-141
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    • 2010
  • Purpose: This study was to examine the effect of Progressive Muscle Relaxation Therapy on stress and anxiety of traffic accident patients. Method: Subjects of this study were 39 hospitalized patients at orthopedic ward. An experimental group received Progressive Muscle Relaxation Therapy five times each week for four weeks beginning from the fourth day following the injury, whereas a control group received regular care. A tape of Jacobson's Progressive Muscle Relaxation Therapy recorded in Korean by the Rheumatoid Health Academic Society was used for relaxation therapy. Data were analyzed using SPSS 13.0 for Windows. Results: Patients who received Progressive Muscle Relaxation Therapy experienced lower level of stress (t=-9.829, p<.001) and anxiety (t=-15.303, p<.001) than those who did not. Conclusion: Progressive Muscle Relaxation Therapy may be an effective nursing intervention to reduce levels of stress and anxiety of traffic accident patients.

Geodesic shape finding of membrane structure with geodesic string by the dynamic relaxation method

  • Lee, K.S.;Han, S.E.
    • Structural Engineering and Mechanics
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    • 제39권1호
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    • pp.93-113
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    • 2011
  • The explicit nonlinear dynamic relaxation method (DRM) is applied to the nonlinear geodesic shape finding analysis by introducing fictional tensioned 'strings' along the desired seams with a three or four-node membrane element. A number of results from the numerical example for the nonlinear geodesic shape finding and patterning analysis are obtained by the proposed method to demonstrate the accuracy and efficiency of the developed method. Therefore, the proposed geodesic shape finding algorithm may improve the applicability of a four-node membrane element to membrane structural engineering and design analysis simultaneously for the shape finding, stress, and patterning analysis.

Successive Over Relaxation 방법을 이용한 임의 형상 단면의 비틀림 특성연구 (Successive Over Relaxation Method in Torsion Problem for General Shaped Section)

  • 윤태양;김태진
    • 콘크리트학회지
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    • 제6권1호
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    • pp.101-110
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    • 1994
  • 본 연구에서는 임의형상의 속의 찬 또는 중공 단면에 대한 비틀림 상수 및 전단응력 계산용 범용 프로그램 TORSION을 소개한다. Membrane Analogy로부터 차분법을 유도한 뒤 Successive Over Relaxation 방법을 사용하여 정해를 효과적으로 얻을 수 있었다. 사각단면 이외 단면의 경우, 경계조건을 전체 Boundary Mesh에 대하겨 계산 입력해야하는 번거러움을 해격하기 위하여 자동경계 생성기법을 사용하였다. 개발된 프로그램 TORSION을 사용한 Parametric 해석을 통하여 비교적 정확한 일반 중공단면용 비틀림상수 계산을 위한 개략식을 제안한후, 콘크리트 표준시방서에 제시된 방법과 비교하였다.

Steel Cord 선재의 판류응력 평가 및 완화에 관한 연구 (The Evaluation and Relaxation of Residual Stress of Steel Cord)

  • 이상곤;황원호;김병민;배철민;이충열
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2006년도 춘계학술대회 논문집
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    • pp.191-194
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    • 2006
  • Recently the quality improvement of the steel cord product is demanded by the tire market. After wire drawing process, produced residual stresses have a harmful effect on the durability of the wire and become the cause which decreases the quality of the product. Therefore, to improve the quality of the steel cord product, the research regarding the method of residual stress relaxation is necessary. To evaluate the quality of the drawn wire, it is important to measure the residual stress, because the residual stress decides a variety of the quality level which is demanded in the drawn wire. This study proposed a residual stress relaxation method in the drawn wire using FE analysis. The validity of the analysis results was verified by nanoindentation test.

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