• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.04a
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• pp.17-21
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• 1989

SSI2D/3D is a computer program to calculate dynamic stiffness matrix of the foundation for soil-structure-interaction problem in frequency demain. It is written in FORTRAN 77 and applicable to two or three dimensional situations. In this paper the program structure is summarized. Two examples aye shown to demonstrate the possibilities of the Boundary Element Method applied to dynamic problems in infinite domains.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.6
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• pp.950-956
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• 2013

This paper describes a sensitivity-coefficient-based iterative method for detecting cracks in a structure. The sensitivity coefficients of a cracked structure are obtained by changing its eigenvectors. The proposed method is applied to a cracked cantilever. The crack is modeled as a rotational stiffness. The predicted cracks are in good agreement with those from a structural reanalysis of the cracked structure.

• Journal of the Korean Mathematical Society
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• v.32 no.4
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• pp.849-856
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• 1995

There are some papers on structure theorems for the spaces of matrices over certain semirings. Beasley, Gregory and Pullman [1] obtained characterizations of semiring rank 1 matrices over certain semirings of the nonnegative reals. Beasley and Pullman [2] also obtained the structure theorems of Boolean rank 1 spaces. Since the semiring rank of a matrix differs from the column rank of it in general, we consider a structure theorem for semiring rank in [1] in view of column rank.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.461-468
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• 2004

Modal participation factor(MPF) is essential to analyze structural response under earthquake load. MPF of real structure differs from that of analytic mathematical model due to the error induced from analytical assumption and construction. In this study, a identification method is proposed to calculate the MPF of real structure based on H∞ optimal model reduction. The MPF is obtained from the relationship between observability, controllability matrix of realized from S.I. and typical 2-degree state space model. The proposed method is verified thorough examples.

• Journal of Advanced Marine Engineering and Technology
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• v.16 no.5
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• pp.29-38
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• 1992

This paper describes the general formulation for the in-plane longitudinal and flexural coupled free vibration analysis of a branched structure. The branched structure, which is mainly found in machine tools, pipeline systems and so on, has some crooked parts and subsystems. And it modeled as a distributed mass system. The superiority of the present method to the transfer matrix method in the computation accuracy and speed was confirmed by the numerical computation results. Moreover, we comfirmed that boundary and intermediate conditions have been controlled by the spring constants.

• Journal of the Korean Mathematical Society
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• v.54 no.5
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• pp.1441-1456
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• 2017

We consider a 3-dimensional Riemannian manifold M with a circulant metric g and a circulant structure q satisfying $q^3=id$. The structure q is compatible with g such that an isometry is induced in any tangent space of M. We introduce three classes of such manifolds. Two of them are determined by special properties of the curvature tensor. The third class is composed by manifolds whose structure q is parallel with respect to the Levi-Civita connection of g. We obtain some curvature properties of these manifolds (M, g, q) and give some explicit examples of such manifolds.

• YAKHAK HOEJI
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• v.25 no.4
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• pp.175-179
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• 1981

Rheological studies on the gelatin hydrogels were carried out by rheometer. In the temperature range of $32^{\circ}~90{\circ}C$, the viscosities of the gelatin hydrogels were measured. In order to observe the formation of gel structure, the stress-relaxation tests of the creep-curves were investigated. The structure of viscoelastic substance could be considered of a three dimensional crosslinked matrix. As the result viscoelastic coefficients were obtained by Maxwell element, which are correspond to the network structure. From the relationship between the stress-relaxation time and temperature, activation energy correspond to breaking the formation of gels was calculated to be 13.91kcal/mole.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.153-160
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• 2007

In this paper, the exact analysis of the parallel coupled line with open stub is presented. This structure shows LPF characteristics with broad stopband and sharp skirt characteristics. We derived the exact Z-matrix expression of the structure. In order to show the validation of the expression we designed $3^{th}$ order Chebyshev LPF using the structure. The simulated data excellently agreed with the predicted values by the calculation using the derived expression.

• Journal of the Chungcheong Mathematical Society
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• v.10 no.1
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• pp.127-139
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• 1997

The spherical non-commutative $\mathbb{S}_{\omega}$ were defined in [2,3]. Assume that no non-trivial matrix algebra can be factored out of the $\mathbb{S}_{\omega}$, and that the fibres are isomorphic to the tensor product of a completely irrational non-commutative torus with a matrix algebra $M_k(\mathbb{C})$. It is shown that the tensor product of the spherical non-commutative torus $\mathbb{S}_{\omega}$ with the even Cuntz algebra $\mathcal{O}_{2d}$ has a trivial bundle structure if and only if k and 2d - 1 are relatively prime, and that the tensor product of the spherical non-commutative torus $S_{\omega}$ with the generalized Cuntz algebra $\mathcal{O}_{\infty}$ has a non-trivial bundle structure when k > 1.

• Journal of the Korean Institute of Telematics and Electronics
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• v.9 no.4
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• pp.25-32
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• 1972

This paper: a) discusses the structure of Korean charactors from a unified point of view. The forming process of vowels, consonants, and the combined characters are described in the same way. b) makes clear that vowels and consonants are unique determinants of combined characters according to speech sound. c) describes the way in which 10 vowels and 14 consonants are arranged systematically by the matrix equation, which forms 14,364 kinds of combined characters.