• 한국공간정보시스템학회:학술대회논문집
• /
• 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
• /
• pp.161-168
• /
• 2004

The dynamic instability of snapping phenomena has been studied by many researchers. Few papers deal with dynamic buckling under loads with periodic characteristics, and the behavior under periodic excitations is expected to be different from behavior under STEP excitations. We investigate the fundamental mechanisms of the dynamic instability when the sinusoidally shaped arch structures are subjected to sinusoidally distributed excitations with pin-ends. The mechanisms of dynamic indirect snapping of shallow arches are especially investigated under not only STEP function excitations but also under sinusoidal harmonic excitations, applied in the up-and-down direction. The dynamic nonlinear responses are obtained by the numerical integration of the geometrically nonlinear equation of motion, and examined by Fourier spectral analysis in order to get the frequency-dependent characteristics of the dynamic instability for various load levels.

• 대한치과의사협회지
• /
• 제9권1호
• /
• pp.43-48
• /
• 1971

The purpose of this study is to evaluate the influence of genetics of the dimensions of dental arches in twins. Thirty-four pairs of Korean twins, of which twenty-three were monozygotic and eleven dizygotic, participated in the study. The twins ranged in age from 6 years to 12 years with mixed dentition. The results were as follows: 1) No significant differences were observed between male and female in mean interpair diffenences of monozygotic twins. 2) Mean interpair differences of monozygotic twins were lesser than these of dizygotic twins. 3) Highly significiant zygotic differences were observed in the mean interpair differences of the width of upper and lower dental arch. This suggest that there is a significant component of hereditary variability.

• 대한토목학회논문집
• /
• 제9권3호
• /
• pp.13-19
• /
• 1989

박판으로 이루어진 아치가 양단에서 휨모멘트를 받을 때 발생하는 횡좌굴에 대한 지배 미분방정식이 제시되었다. 미분방정식은 updated Lagrangian 방법에 따른 증분형태의 가상일의 원리에 의하여 유도 되었다. 본 연구에서 구한 임계모멘트 값들을 다른 결과들과 비교함으로써 본 연구의 타당성을 검토하여 보았다.

• Structural Engineering and Mechanics
• /
• 제3권5호
• /
• pp.511-525
• /
• 1995

The differential equations governing in-plane free vibrations of the elastic, catenary arch with rotatory inertia are derived in Cartesian coordinates. Frequencies and mode shapes are computed numerically for such arches with unsymmetric axes, for both clamped-clamped and hinged-hinged end constraints. The lowest four natural frequency parameters are reported, with and without rotatory inertia, as a function of three nondimensional system parameters; the span to cord length ratio e, the slenderness ratio s, and the rise to cord length ratio f. Experimental measures of frequencies and mode shapes for several laboratory-scale catenary models serve to validate the theoretical results.

• Journal of Korean Dental Science
• /
• 제10권2호
• /
• pp.74-81
• /
• 2017

This report describes two cases of complete arch implant-supported restorations. The first patient had seven dental implants in each arch with monolithic zirconia frameworks. At four weeks' follow-up, the one-piece maxillary framework was fractured, which was re-designed and re-fabricated using laser-sintered cobalt-chrome alloy. The second patient had four implants in the mandible only. A mandibular monolithic zirconia framework and a maxillary conventional complete denture were fabricated and delivered. At five years' follow-up, the patient reported no significant discomfort. Careful consideration and monitoring of the status of antagonistic arches and stress distribution on zirconia frameworks were suggested for complete arch implant-supported fixed restorations.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 추계학술대회논문집
• /
• pp.768-771
• /
• 2005

The purpose of this paper is to investigate the free vibration of stepped noncircular arches. Taking into account the effects of axial deformation, rotatory inertia and shear deformation, the governing differential equations are solved numerically for the elliptic and sinusoidal geometries with hinged-hinged, hinged-clamped, and clamped-clamped end constraints. The lowest four natural frequencies are presented as functions of four non-dimensional system parameters: the arch rise to span length ratio, the slenderness ratio, the section ratio, and the discontinuous sector ratio.

• 대한두개안면성형외과학회지
• /
• 제23권5호
• /
• pp.241-245
• /
• 2022

Cervical chondrocutaneous branchial remnants are very rare congenital lesions of the lateral neck; thus, our knowledge of this condition derives almost entirely from occasional case reports in the literature. They are thought to originate from the branchial arches and, therefore, can be found anywhere on the pathway along which those branchial arches migrate during embryogenesis. We report the case of a 5-year-old girl presenting with a cervical chondrocutaneous branchial remnant on the right lateral neck that had existed since birth, with no other anomalies.

• Nonlinear Functional Analysis and Applications
• /
• 제27권2호
• /
• pp.405-432
• /
• 2022

Cracks in beams and shallow arches are modeled by massless rotational springs. First, we introduce a specially designed linear operator that "absorbs" the boundary conditions at the cracks. Then the equations of motion are derived from the first principles using the Extended Hamilton's Principle, accounting for non-conservative forces. The variational formulation of the equations is stated in terms of the subdifferentials of the bending and axial potential energies. The equations are given in their abstract (weak), as well as in classical forms.

• 대한치과의사협회지
• /
• 제23권3호통권190호
• /
• pp.237-254
• /
• 1985

• 천문학회보
• /
• 제31권1호
• /
• pp.36-36
• /
• 2006