• Structural Engineering and Mechanics
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• v.22 no.2
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• pp.131-150
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• 2006

Exact analytical solutions for in-plane static problems of planar curved beams with variable curvatures and variable cross-sections are derived by using the initial value method. The governing equations include the axial extension and shear deformation effects. The fundamental matrix required by the initial value method is obtained analytically. Then, the displacements, slopes and stress resultants are found analytically along the beam axis by using the fundamental matrix. The results are given in analytical forms. In order to show the advantages of the method, some examples are solved and the results are compared with the existing results in the literature. One of the advantages of the proposed method is that the high degree of statically indeterminacy adds no extra difficulty to the solution. For some examples, the deformed shape along the beam axis is determined and plotted and also the slope and stress resultants are given in tables.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.2
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• pp.322-330
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• 1987

Isotropic linear viscoelasticity problems are analyzed numerically in time domain by Boundary Element Method with quadratic isoparametric boundary elements. Viscoelastic fundamental solutions are newly derived by using the elastic-viscoelastic correspondence principle and corresponding boundary integral equations are also presented. Numerical results of two examples are compared with the derived exact solutions to verify the accuracy and validity of the method. A detailed study on the accuracy of displacement and stress in terms of time integration step is given.

• Structural Engineering and Mechanics
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• v.22 no.1
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• pp.1-16
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• 2006

This paper presents a virtual boundary element-equivalent collocation method (VBEM) for the plane magnetoelectroelastic solids, which is based on the fundamental solutions of the plane magnetoelectroelastic solids and the basic idea of the virtual boundary element method for elasticity. Besides all the advantages of the conventional boundary element method (BEM) over domain discretization methods, this method avoids the computation of singular integral on the boundary by introducing the virtual boundary. In the end, several numerical examples are performed to demonstrate the performance of this method, and the results show that they agree well with the exact solutions. So the method is one of the efficient numerical methods used to analyze megnatoelectroelastic solids.

• Korea Trade Review
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• v.46 no.6
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• pp.127-142
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• 2021

The Pohang Youngilman Port is the only international trade port in the Daegu-Gyeongbuk region, but its cargo throughput has been stagnated since its opening. Finding out ways to revitalize the port has been a big issue in the region, taking its potential business effects on the surrounding areas into consideration. This study, therefore, aimed to critically evaluate the government policies and empirically analyze business environments of the Pohang Youngilman Port as a fundamental to reach solutions for its revitalization. The policy evaluation showed that there are discrepancies in viewing contexts, implementations and mechanisms of the port at each government level, which resulted in implementing various but inconsistent solutions. Also, the interview results were analyzed to point out the fundamental problems, such as limited cargo volume due to weak hinterland development, lack of shuttle shipping between Busan New Port and Pohang Youngilman Port, and lack of large shippers to diverse the shipping network. This study has academic and managerial implications in suggesting measures for facilitation of the Pohang Youngilman Port by amalgamating various viewpoints of governments and stakeholders, which can be used for policy development as well as practical solutions for the port.

• Bulletin of the Korean Mathematical Society
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• v.44 no.4
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• pp.663-675
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• 2007

We investigate the representation of the solution of discrete linear Volterra difference systems by means of the resolvent matrix and fundamental matrix, respectively, and then study the boundedness of the solutions of discrete Volterra systems by improving the assumptions and the proofs of Medina#s results in [6].

• Journal of the Korean Mathematical Society
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• v.48 no.4
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• pp.867-885
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• 2011

We study a class of quasilinear wave equations with strong and nonlinear viscosity. By using the perturbation method for semilinear parabolic equations, we have established the fundamental results on existence, uniqueness and continuous dependence on data of weak solutions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.324-327
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• 1995

In this research, FEM solution to analysis near field of high Tc superconductor microstrip antenna is presented. This method uses the interpolation function with vector edge triangular element. The advantage of this element is elimination of spurious solutions which are attributed to the lack of enforcement of the divergence condition. The solutions of this method will be used to have a good fundamental data for next reaserch about analysis of HTS microstrip array antenna etc.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.3 s.18
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• pp.157-164
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• 2004

This is a boundary integral formulation for elastic shallow shell structures subjected to both membrane and bending loads. Fundamental solutions for shell actions are determined from the plate solutions and, finally the corresponding kernel functions for shell BIEs can be constructed. It is illustrated by solving an example of uniform load of spherical cap.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.3
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• pp.237-244
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• 2006

In this paper, we examine the existence and bounded- ness of the solutions of discrete Volterra equations $$x(n)=f(n)+\sum_{j=0}^{n}g(n,j,x(j))$$, $n{\geq}0$ and $$x(n)=f(n)+\sum_{j=0}^{n}B(n,j)x(j)$$, $n{\geq}0$.

• Journal of the Korean Mathematical Society
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• v.44 no.2
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• pp.443-453
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• 2007

We study the equation of a membrane with strong viscosity. Based on the variational formulation corresponding to the suitable function space setting, we have proved the fundamental results on existence, uniqueness and continuous dependence on data of weak solutions.