• 제목/요약/키워드: Rotatory

검색결과 204건 처리시간 0.022초

Traumatic Atlantoaxial Rotatory Fixation with Accompanying Odontoid and C2 Articular Facet Fracture

  • Oh, Jong-Yang;Chough, Chung-Kee;Cho, Chul-Bum;Park, Hae-Kwan
    • Journal of Korean Neurosurgical Society
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    • 제48권5호
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    • pp.452-454
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    • 2010
  • Traumatic atlantoaxial rotatory fixation (AARF) with accompanying odontoid and C2 articular facet fracture is a very rare injury, and only one such case has been reported in the medical literature. We present here a case of a traumatic AARF associated with an odontoid and comminuted C2 articular facet fracture, and this was treated with skull traction and halo-vest immobilization for 3 months. After removal of the halo-vest immobilization, his neck pain was improved and his neck motion was preserved without any neurologic deficits although mild torticolis was still observed in closer inspection.

In-plane free vibrations of catenary arches with unsymmetric axes

  • Wilson, James F.;Lee, Byoung Koo
    • Structural Engineering and Mechanics
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    • 제3권5호
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    • pp.511-525
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    • 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.

회전관성 및 전단변형을 고려한 변단면 포물선 아치의 자유진동 (Free Vibrations of Tapered Parabolic Arches Considering Rotatory Inertia and Shear Deformation)

  • 오상진;박광규;최규문;이종국
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 춘계학술대회논문집
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    • pp.846-851
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    • 2003
  • The differential equations governing free, in-plane vibrations of non-circular arches with non-uniform cross-section, including the effects of rotatory inertia, shear deformation and axial deformation, are derived and solved numerically to obtain frequencies. The lowest four natural frequencies are calculated for the prime parabolic arches with hinged-hinged, hinged-clamped, and clamped-clamped end constraints. Three general taper types for rectangular section are considered. A wide range of arch rise to span length ratios, slenderness ratios, and section ratios are considered. The agreement with results determined by means of a finite element method is good from an engineering viewpoint.

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회전관성 효과를 고려한 차륜의 동특성 (Dynamic characteristics of train wheel with considering the effects of rotatory inertia)

  • 김광식;박문태
    • 오토저널
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    • 제9권1호
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    • pp.49-56
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    • 1987
  • This study is a part f the research on the coupled vibration of train wheel with stepped thickness and rail. The research was conducted for the purpose of examining the dynamic characteristics of train wheel which considered the effect of rotatory inertia and preventing the vibrations of the high speed railway. The In-plane compressive stresses were computed by the rotation of train wheel and the reaction depending on the condition of rolling. The equation of transverse vibration of the train wheel was obtained by Lagrange's equation. As a result of study, it is known that the effect of rotatory inertia and the increment of thickness ratio, h over bar decrease frequency but the increment of radius ratio, r over bar increase frequency.

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Free vibrations of circular arches with variable cross-section

  • Wilson, James F.;Lee, Byoung Koo;Oh, Sang Jin
    • Structural Engineering and Mechanics
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    • 제2권4호
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    • pp.345-357
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    • 1994
  • The differential equations governing free, in-plane vibrations of linearly elastic circular arches with variable cross-sections are derived and solve numerically for quadratic arches with three types of rectangular cross sections. Frequencies, mode shapes, cross-sectional load distributions, and the effects of rotatory inertia on frequencies are reported. Experimental measurements of frequencies and their corresponding mode shapes agree closely with those predicted by theory. The numerical methods presented here for computing frequencies and mode shapes are efficient and reliable.

자유단에 집중질량을 갖는 캔틸레버형 변단면 보의 자유진동 (Free Vibrations of Tapered Cantilever-Type Beams with Tip Mass at the Free End)

  • Oh, Sang-Jin;Lee, Jae-Young;Park, Kwang-Kyou;Mo, Jeong-Man
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.394.1-394
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    • 2002
  • The purpose of this paper is to investigate the natural frequencies and mode shapes of tapered beams with general boundary condition(translational and rotational elastic support) at one end and carrying a tip mass of rotatory inertia at the other end. The beam model is based on the classical Bernoulli-Euler beam theory which neglects the effects of rotatory inertia and shear deformation. (omitted)

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카이로프랙틱 후 발생한 환축추 아탈구 및 후천성 사경 (Torticollis and Atlantoaxial Rotatory Subluxation after Chiropractic Therapy)

  • 김도영;윤왕현;박진영;박중현
    • Clinical Pain
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    • 제18권2호
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    • pp.92-96
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    • 2019
  • Torticollis is an abnormal, asymmetric head or neck position which usually caused by imbalance of paracervical muscles. The traumatic torticollis can be caused by following events; atlantoaxial rotatory subluxation, atlantoaxial dislocation, cervical vertebral fractures, and injury to the cervical musculature. Especially, acute traumatic atlantoaxial rotatory subluxation usually presents limitation of cervical range of motion without pain or neurologic deficit. We report a case of a 58 year-old man who developed the acute atlantoaxial rotatory subluxation right after the chiropractic therapy, which induced the limitation of cervical range of motion to 52.5% of normal range. The magnetic resonance image revealed the facture of the odontoid process and the partial injury in transverse ligaments of the atlas. He underwent intramuscular botulinum toxin injection and 10 days of continuous cervical traction 15 hours a day using a 5 kg weight. The range of the cervical motion restored up to 90.2% of normal range.

변단면 변화곡율 캔틸레버 아치의 자유진동 (Free Vibrations of Tapered Cantilever Arches with Variable Curvature)

  • 이병구;이용수;오상진
    • 소음진동
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    • 제10권2호
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    • pp.353-360
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    • 2000
  • Numerical methods are developed for calculating the natural frequencies and mode shapes of the tapered cantilever arches with variable curvature. The differential equations governing the free vibrations of such arches are derived and solved numerically, in which the effect of rotatory inertia is included. The parabolic shape is chosen as the arch with variable curvature while both the prime and quadratic arched members are considered as the tapered arch with variable curvature while both the prime and quadratic arched members are considered as the tapered arch. Comparisons the natural jfrequencies between this study and finite element method SAP 90 seve to validate the numerical method developed herein. The lowest four natural frequencies are reported as a function of four non-dimensional system parameters. The effects of both the rotatory inertia and cross-sectional shape are reported. Also, the typical mode shapes of stress resultants as well as the displacements are reported.

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Leipholz 기둥의 안정성에 미치는 자유단의 탄성구속과 말단질량의 영향 (Influence of Elastic Restraints and Tip Mass at Free End on stability of Leipholz Column)

  • 윤한익;박일주;진종태;김영수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
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    • pp.309-315
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    • 1996
  • An analysis is presented on the stability of elastic cantilever column subjected to uniformly distributed follower forces as to the influence of the elastic restraints and a tip mass at the free end. The elastic restraints are formed by both the translational and the rotatory springs. For this purpose, the governing equations and boundary conditions are derived by using Hamilton's principle, and the critical flutter loads and frequencies are obtained from the numerical evaluation of the eigenvalue functions of this elastic system. The added tip mass increases as a whole the critical flutter load in this system, but the presence of its moment of inertia of mass has a destabilizing effect. The existence of the translational and rotatory spring at the free end increases the critical flutter load of the elastic cantilever column. Nevertheless their effects on the critical flutter load are not uniform because of their coupling. The translational spring restraining the end of cantilever column decreases the critical flutter load by coupling with a large value of tip mass, while by coupling with the moment of inertia of tip mass its effect on the critical flutter load is contrary. The rotatory spring restraining the free end of cantilever column increases the critical flutter load by coupling with the tip mass, but decreases it by coupling with the moment of inertia of tip mass.

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