• Structural Engineering and Mechanics
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• v.71 no.4
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• pp.341-350
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• 2019

Exterior beam-column joint is typically the weakest link in a limited-ductile reinforced concrete (RC) frame structure. The use of diagonal haunch element has been considered as a desirable seismic retrofit option for reducing the seismic demand at the joint. Previous research globally has focused on implementing double haunches, while the use of single haunch element as a less-invasive and more architecturally favorable retrofit option has not been investigated. In this paper, the key formulations and a design procedure for the single haunch system for retrofitting RC exterior beam-column joint are developed. An application of the proposed design procedure is then illustrated through a case study.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.4
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• pp.780-806
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• 1995

The purpose of this study was to describe the application of 3D finite element analysis to determine resultant stresses on the bone anchored fixed prosthesis, implants and supporting bone of the mandible according to fixture numbers and load conditions. 4 or 6 fixtures and the bone anchored fixed prosthesis were placed in 3D finite element mandibular arch model which represents an actual mandibular skull. A $45^{\circ}$ diagonal load of 10㎏ was labiolingually applied in the center of the prosthesis(P1). A $45^{\circ}$ diagonal load of 20㎏ was buccolingually applied at the location of the 10mm or 20mm cantilever posterior to the most distal implant(P2 or P3). The vertical distribution loads were applied to the superior surfaces of both the right and the left 20mm cantilevers(P4). In order that the boundary conditions of the structure were located to the mandibular ramus and angle, the distal bone plane was to totally fixed to prevent rigid body motion of the entire model. 3D finite element analysis was perfomed for stress distribution and deflection on implants and supporting bone using commercial software(ABAQUS program. for Sun-SPARC Workstation. The results were as follows : 1. In all conditions of load, the hightest tensile stresses were observed at the metal lates of prostheses. 2. The higher tensile stresses were observed at the diagonal loads rather than the vertical loads 3. 6-implants cases were more stable than 4-implants cases for decreasing bending and torque under diagonal load on the anterior of prosthesis. 4. From a biomechanical perspective, high stress developed at the metal plate of cantilever-to-the most distal implant junctions as a consequence of loads applied to the cantilever extension. 5. Under diagonal load on cantilever extension, the 6-implants cases had a tendency to reduce displacement and to increase the reaction force of supporting point due to increasing the bendign stiffness of the prosthesis than 4-implants cases. 6. Under diagonal load on cantilever extension, the case of 10mm long cantilever was more stable than that of 20mm long cnatilever in respect of stress distribution and displacement. 7. When the ends of 10mm or 20mm long cantilever were loaded, the higher tensile stress was observed at the second most distal implant rather than the first most distal implant. 8. The 6-implants cases were more favorable about prevention of screw loosening under repeated loadings because 6-implants cases had smaller deformation and 4-implants cases had larger deformation.

• Proceedings of the Acoustical Society of Korea Conference
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• 1993.06a
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• pp.206-209
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• 1993

The main purpose of this paper is to verify the effectiveness of a high resolution direction finding method, so called the‘averaged MUSIC’. This method uses a new sample array covariance matrix that consists of diagonal components obtained by taking averages of the diagonal component values of the sample covariance matrix for the MUSIC. The paper shows that the proposed method performs higher resolved direction-of-arrival estimation and better resolution probability than the MUSIC in such cases as low signal-to-noise ratio, when the number of sensors used is finite, based on the statistical analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.04a
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• pp.113-118
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• 1993

A method for approximating the failure surfaces for columns in compression and biaxial bending was proposed by using the moments along the line of a diagonal of the section. This method showed the better approximations for the failure surfaces of columns than the method of ACI. To calculate the moments along the line of a diagonal of the section, an approximate method which is not influenced by the number of steel s and the location of inner steels was proposed This method gave satisfactory approximations for practical sections of columns.

• Bulletin of the Korean Mathematical Society
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• v.47 no.3
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• pp.653-661
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• 2010

Let R be a ring, and let $\Psi$(R) be the ideal generated by the set {x $\in$R | 1 + sxt $\in$ R is unit-regular for all s, t $\in$ R}. We show that $\Psi$(R) has "radical-like" property. It is proven that $\Psi$(R) has stable range one. Thus, diagonal reduction of matrices over such ideal is reduced.

• Journal of the Korean Operations Research and Management Science Society
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• v.12 no.1
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• pp.10-18
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• 1987

This paper discusses algorithmic properties of a class of complementarity programs involving strictly diagonally isotone and off-diagonally isotone functions, i. e., functions whose Jacobian matrices have positive diagonal elements and nonnegative off-diagonal elements, A typical traffic equilibrium under elastic demands is cast into this class. Algorithmic properties of these complementarity problems, when a Jacobi-type iteration is applied, are investigated. It is shown that with a properly chosen starting point the generated sequence are decomposed into two converging monotonic subsequences. This and related will be useful in developing solution procedures for this class of complementarity problems.

• Bulletin of the Korean Mathematical Society
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• v.45 no.1
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• pp.95-99
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• 2008

It is known that each eigenvalue of a real symmetric, irreducible, tridiagonal matrix has multiplicity 1. The graph of such a matrix is a path. In this paper, we extend the result by classifying those trees for which each of the associated acyclic matrices has distinct eigenvalues whenever the diagonal entries are distinct.

• Communications of the Korean Mathematical Society
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• v.15 no.1
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• pp.143-153
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• 2000

In [8], Franca and Stenberg developed several Galerkin least squares methods for the solution of the problem of linear elasticity. That work concerned itself only with the error estimates of the method. It did not address the related problem of finding effective methods for the solution of the associated linear systems. In this work, we propose the block diagonal preconditioners. The preconditioned conjugate residual method is robust in that the convergence is uniform as the parameter, v, goes to $\sfrac{1}{2}$. Computational experiments are included.

• Bulletin of the Korean Mathematical Society
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• v.43 no.3
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• pp.635-644
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• 2006

For a lower niltriangular matrix ring $A=NT_n(K)(n{\geq}3)$, we show that every derivation of A is a sum of certain diagonal, trivial extension and strongly nilpotent derivation. Moreover, a strongly nilpotent derivation is a sum of an inner derivation and an uaz-derivation.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.589-592
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• 1996

It is well known that robust compensators designed by the block-diagonal Lyapunov function approaches are conservative while they are popular in practice because of their computational easiness. In this note, we develop a systematized version of conventional block-diagonal Lyapunov function approaches by deriving two separated optimizations based on the guaranteed cost control method. The proposed method generates reasonable robust compensators in practice.