• 대한조선학회논문집
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• 제49권4호
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• pp.287-295
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• 2012

Hydrodynamic performance of a movable submerged breakwater was analyzed using energy dissipation model. Based on two-dimensional boundary element method the equation of motion including a viscous dissipation term proportional to velocity squared was solved by Newton-Raphson method. Energy dissipation coefficients as well as reflection and transmission coefficients of a submerged flat plate were calculated with various plate lengths and thickness. Both real and imaginary components of body displacement and forces were used to solve the motion of breakwater accurately. The effect of the magnitude of dissipation coefficient on the body displacement was evaluated. The results from the potential theory with no dissipation term were found to be an overestimate in resonance frequency.

• 대한기계학회논문집
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• 제12권2호
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• pp.262-270
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• 1988

본 연구에서는 필자들의 수치해석방법을 발전시켜 프로파일링을 한 로울러의 프로파일 시작점부근에서의 압력과 유막의 거동을 보다 상세하게 해석하고자 한다.이를 위하여, 수치해석시 로울러 길이방향의 분할을 불균일하게 하여 프로파일 시작점부근에서의 절점의 간격을 조밀하게 하였으며 윤활유의 압축성효과도 고려하였다.

• 전자공학회논문지B
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• 제33B권4호
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• pp.91-99
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• 1996

A hybrid approach employing both the genetic algorithm and the newton-raphson method is proposed for the electrical impedance computed tomography (EICT) image reconstruction. Computational experiments based on the new concept have shown promising results for several noise-free models. In particular, the resistance distribution of the tested models having resistivity ratio up to 100:1 has been reconstructed sucessfully. Using the proposed mehtod, it is also possible to get the reconstruction by the conventional iterative approaches be difficult to vonverge to a robust solution. If the compution power is enhanced further, the proposed method is expected to stimulate the practical applications of the EICT technology in the near future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.78-80
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• 2005

The load flow calculation is one of the most critical issues in electrical power systems. Generally, load flow has been calculated by Gauss-Seidel method and Newton-Raphson method but these methods have some problems such as non-convergence due to heavy load and initial value. In this paper, to overcome such problems, the power flow is calculated by genetic algorithm. At the heavy load, the solution for problem can not be obtained by the Newton-Raphson method. However, it can be solved in case of using genetic algorithm. In this paper, the strong point of this method would be demonstrated in application to an example system.

• Tribology and Lubricants
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• 제12권3호
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• pp.115-122
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• 1996

In this paper, a finite difference method and the Newton-Raphson method are used to evaluate the Hamrock and Dowson's EHL film thickness formulas in elliptical contact problems. The minimum and central film thicknesses are compared with the Hamrock and Dowson's numerical results for various dimensionless parameters and with their film thickness formulas. The results of present analysis are more accurate and physically reasonable. The minimum film thickness formula is similar with the Hamrock and Dowson's results, however, the central film thickness formula shows large differences. Therefore, the Hamrock and Dowson's central film thickness formula should be replaced by following equation. $H_{c} = 4.88U^{0.68}G^{0.44}W^{0.096}(1-0.58e^{-0.60k})$ More accurate film thickness formula for general elliptical contact problems can be expected using present numerical methods and further research should be required.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.331-338
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• 2000

In this paper, a non-linear finite element formulation for the spatial cable-net structures is simulated and using this formulation, the characteristics of structural behaviors for the elastic catenary cable are examined In the simulating procedure for the elastic catenary cable, nodal forces and tangential stiffness matrices are derived using catenary parameters of the exact solutions by a governing differential equation of catenary cable, cable self-weights and unstressed cable length. Dynamic Relaxation Method that considers kinetic damping is used for the structure analysis and Newton Raphson Method is used to verify the accuracy of solutions. In the analysis of two dimensional cable, the results obtain from the elastic catenary elements are shown more accurate than does of truss elements and in the case of spatial cable-net structures, Dynamic Relaxation Method is more stable to be converged than Newton Raphson Method.

• 한국분말재료학회지
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• 제30권1호
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• pp.29-34
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• 2023

A fixed-point iteration is proposed to integrate the stress and state variables in the incremental analysis of plastic deformation. The Conventional Newton-Raphson method requires a second-order derivative of the yield function to generate a complicated code, and the convergence cannot be guaranteed beforehand. The proposed fixed-point iteration does not require a second-order derivative of the yield function, and convergence is ensured for a given strain increment. The fixed-point iteration is easier to implement, and the computational time is shortened compared with the Newton-Raphson method. The plane-stress condition is considered for the biaxial loading conditions to confirm the convergence of the fixed-point iteration. 3-dimensional tensile specimen is considered to compare the computational times in the ABAQUS/explicit finite element analysis.

• 대한기계학회논문집
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• 제16권10호
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• pp.1890-1899
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• 1992

본 연구에서는 이종재료간의 Ⅴ-노치균열의 노치각도 및 재료의 종류에 따른 응력특이성지수와 응력강도 계수 해석에 각각 뉴톤-랍슨법(newtonraphson method), 뉴톤-랍슨법과 최소자승법을 이용한 선점법(collocation method)인 수치해석적 방법을 응용하고, 광탄성 등색선 무늬를 컴퓨터 그래픽하여 응력특이성지수와 응력강도계수가 모우드(mode)에 미치는 특성과 경계요소법(boundary element method)으로 응력해석한 결과로써 선점법을 이용하여 응력강도계수를 해석하고 기존의 결과등과 비교, 검토하 고자 한다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.97-100
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• 2004

Multivariate Newton Raphson method is developed to perform the particle tracking in the three dimensional area using four objective functions. In this method, three variables are solved to compute target point and actual and real tracking time. The simulated pathlines in various types of three dimensional elements are well matched with exact pathline.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제29회 춘계학술대회
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• pp.182-188
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• 1999

A theoretical study of elastohydrodynamic lubrication of elliptical contacts with both rolling and spin has been carried out. A finite difference method and the Newton-Raphson method are applied to solve the problem. The velocity vectors resulting from combined spin and rolling/sliding motion lead to asymmetric pressure distributions and film shapes. Film contours and variations of the minimum and central film thicknesses are compared with various spin-roll ratios. At high spin-roll ratios the minimum film thickness is considerably reduced, whereas the central film thickness decreases less dramatically, The present numerical scheme can be used in the analysis of general elliptical contact problems.