• Title/Summary/Keyword: Elastica

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Growth Responses and Introduction Plan of Interior Landscape Plants under Light Intensity of Fluorescent Light and Sunlight (형광등과 자연광의 광도에 따른 실내조경식물의 생육반응과 도입 방안)

  • Choi Kyoung-Ok;Lee Sang-Woo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.4 s.111
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    • pp.119-128
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    • 2005
  • This study was carried out to obtain fundamental information of growth response of interior landscape plants under a fluorescent lighting, a sunlight at indoor. Ficus elastica Roxb. vu. decora Hort, Spathiphyllum 'Clevelandii', Codiaeum variegatum Blume var. pictum Mvell. Arg. 'Exalant' and Cordyline terminalis Kunth var. red edge Hort were examined under 100lux, 500lux, 1,000lux and 2,000lux light intensity consisted of fluorescent lighting and sunlight at indoor condition. Result of experiments are as follows; 1. A Ficus elastica Roxb. var. decora Hort plant growth status was better showed under fluorescent lighting than sunlight. A plant growth status showed the best result under 2,000lux light intensity of fluorescent lighting in cases of all conditions. 2. A Spathiphyllum 'Clevelandii' showed the best effective adaptations under law intensity among experimental plants. A Spathiphyllum 'Clevelandii', plant growth status was better showed under fluorescent lighting than sunlight. A plant growth status showed the best result under 1,000lux light intensity of fluorescent lighting in cases of all conditions. 3. It need the best high establishment of fluorescent lighting among experimental plants for good plant growth. A Codiaeum variegatum Blume var. pictum Mvell. Arg. 'Exalant' plant growth status was better showed under fluorescent lighting than sunlight. A plant growth status was better showed under high light intensity in case of same light source. A plant growth status showed the best result under 2,000lux light intensity of fluorescent lighting. 4. A Cordyline terminalis Kunth var. red edge Hort plant growth status was better showed under fluorescent lighting than sunlight. but, A plant growth status was better showed under $500lux\sim1,000lux$ than 2,000lux in cases of all intensity of fluorescent lighting. while, A plant growth status was better showed under $1,000lux\sim2,000lux$ in cases of all intensity of sunlight.

The Simulation and Experiment of Flexible Media with High Exit Velocity (고속의 출구속도를 가지는 유연매체의 거동해석 및 실험)

  • Hong, Sung-Kwon;Jee, Jung-Geun;Jang, Yong-Hoon;Park, No-Cheol;Park, Young-Pil
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.380-383
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    • 2006
  • The media transport system is used in a printer, a ATM(Automated Tellor Machine), and so on. The media transport system has many problems through miniaturization and rapid transportation of these machines. In the paper feeding mechanism, it is important to feed the sheet without jamming under any conditions. To avoid sheet jamming, first we need to predict the behavior of the sheet exactly. In this paper, the analysis of media behavior is based on J. Stolte's studies. In all of OA machines, a flexible beam or plate is pushed from the channel. The motion may be constrained by guides. This leads to a transient and geometrically nonlinear problem. The behavior of paper is simulated by dynamic elastica theory. The shape of guide is represented by parametric cubic curve. But J. Stolte's studies did not considered contact condition between sheet and guide. So Klarbring's Model. will be applied. And the analysis of flexible media has to include aerodynamic effect for more exact behavior analysis, because the flexible media can be deformed drastically by a little force. Therefore aerodynamic force must be applied to the governing equation. Lastly, the simulation of this model is performed, and the experiment is performed for verification of this model. The experimental results of low exit velocity are consistent with the simulation results, however experimental results of high exit velocity do not agree well with analytical results. The reason is that there may be other effects like nip Phenomena

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Geometrical Non-linear Analyses of Tapered Variable-Arc-Length Beam subjected to Combined Load (조합하중을 받는 변단면 변화곡선 보의 기하 비선형 수치해석)

  • Lee, Byoung-Koo;Oh, Sang-Jin;Lee, Tae-Eun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.2
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    • pp.129-138
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    • 2012
  • This paper deals with geometrical non-linear analyses of the tapered variable-arc-length beam, subjected to the combined load with an end moment and a point load. The beam is supported by a hinged end and a frictionless sliding support so that the axial length of the deformed beam can be increased by its load. Cross sections of the beam whose flexural rigidities are functionally varied with the axial coordinate. The simultaneous differential equations governing the elastica of such beam are derived on the basis of the Bernoulli-Euler beam theory. These differential equations are numerically solved by the iteration technique for obtaining the elastica of the deformed beam. For validating theories developed herein, laboratory scaled experiments are conducted.

Geometrical Non-linear Analyses of Tapered Cantilever Column Subjected to Sub-tangential Follower Force (경사 종동력을 받는 변단면 기하 비선형 캔틸레버 기둥의 수치해석)

  • Lee, Byoung-Koo;Oh, Sang-Jin;Lee, Tae-Eun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.1
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    • pp.29-38
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    • 2013
  • This paper deals with geometrical non-linear analyses of the tapered cantilever column subjected to the sub-tangential follower force at the free end. Cross-sections of the column whose flexural rigidities are functionally varied with the axial coordinate. The differential equations governing the elastica of such column are derived on the basis of the large deformation theory. These differential equations have three unknown parameters of the vertical and horizontal deflections and rotation at the free end. These differential equations are numerically solved by the iteration technique for obtaining three unknowns and elastica of the deformed column. For validating theories developed herein, laboratory scaled experiments are conducted.

ON RIVLIN-ERICKSON ELASTICO-VISCOUS FLUID HEATED AND SOLUTED FROM BELOW IN THE PRESENCE OF COMPRESSIBILITY, ROTATION AND HALL CURRENTS

  • Gupta, Urvashi;Sharma, Gaurav
    • Journal of applied mathematics & informatics
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    • v.25 no.1_2
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    • pp.51-66
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    • 2007
  • A layer of compressible, rotating, elastica-viscous fluid heated & soluted from below is considered in the presence of vertical magnetic field to include the effect of Hall currents. Dispersion relation governing the effect of viscoelasticity, salinity gradient, rotation, magnetic field and Hall currents is derived. For the case of stationary convection, the Rivlin-Erickson fluid behaves like an ordinary Newtonian fluid. The compressibility, stable solute gradient, rotation and magnetic field postpone the onset of thermosolutal instability whereas Hall currents are found to hasten the onset of thermosolutal instability in the absence of rotation. In the presence of rotation, Hall currents postpone/hasten the onset of instability depending upon the value of wavenumbers. Again, the dispersion relation is analyzed numerically & the results depicted graphically. The stable solute gradient and magnetic field (and corresponding Hall currents) introduce oscillatory modes in the system which were non-existent in their absence. The case of overstability is discussed & sufficient conditions for non-existence of overstability are derived.

Numerical Analysis of Large Deflections of Cantilever Beams (캔틸레버 보의 과대처짐 해석)

  • Lee, Byoung Koo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.10 no.1
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    • pp.1-7
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    • 1990
  • A method is developed for solving the elastica of cantilever beam subjected to a tip point load and uniform load. The Bernoulli-Euler differential equation of deflected beam is used. The Runge-Kutta method and the Regula Falsi method are used to perform the integration of the differential eqution and to determine the horizontal deflection, respectively. The horizontal and vertical deflections of the free end, and the free-end rotations are calculated for a range of parameters representing variations in tip point load and uniform load. All results are presented in nondimensional forms. And some typical elastic are also presented.

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Non-Linear Behavior of Shear Deformable Simple Beam with a Concentrated Load (전단변형을 고려한 집중하중을 받는 단순보의 비선형 거동)

  • 이병구;이태은;안대순;김권식
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.04a
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    • pp.53-60
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    • 2003
  • This paper explores the governing differential equations for the non-linear behavior of shear deformable simple beam with a concentrated load. In order to apply the Bernoulli-Euler beam theory to simple beam, the bending moment equation on any point of the elastica is obtained by concentrated load. The Runge-Kutta and Regula-Felsi methods, respectively, are used to integrate the governing differential equations and to compute the beam's rotation at the left end of the beams. The characteristic values of deflection curves for various load parameters are calculated and discussed

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Buckling Loads and Post-Buckling Behavior of Linear Tapered Columns (선형 변단면 기둥의 좌굴하중 및 후좌굴 거동)

  • Lee Tae-Eun;Ahn Dae-Soon;Lee Seung-Woo;Park Kwang-Kyou
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.689-696
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    • 2006
  • This paper deals with the geometrical non-linear analyses of the buckled columns. Differential equations governing elasticas of the buckled columns are derived, in which both effects of taper type and shear deformation are included. Three kinds of taper types such as breadth, depth and square tapers are considered. Differential equations are solved numerically to obtain the elasticas and buckling loads of such columns. End constraint of both clamped ends and both hinged ends are considered. The effects of shear deformation on the elastica of the buckled column and buckling load of column are investigated extensively. Experimental studies are presented that complement theoretical results of non-linear responses of the elasticas.

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An Experimental Study on Chaotic Vibrations of a Thin Beam under Torsional Excitation (지지부에 비틀림 하중을 받는 얇은 빔의 혼돈역학에 관한 실험적 연구)

  • 권태호;주재만;박철희
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1995.10a
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    • pp.191-196
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    • 1995
  • 지지부에 비틀림 하중을 받는 Elstica는 비틀림 운동을 하며, 그 가진 주파수가 굽힘모드 근처일 때는 해당하는 굽힘 모드의 운동까지도 동시에 존재하게 된다. 이때 가진력의 크기가 작을때는 주기적인 운동이 된다. 가진력의 크기가 증가함에 따라 굽힘 운동은 굽힘 1차 모드와 연성된 유사주기운동이 발생하며, 이떤 범위 이상이 되면 굽힘 운동과 비틀림 운동이 결합된 진폭이 매우 크고 불규칙적인 비평면 운동(out of plane motion)이 발생하게 되며 이 때의 운동은 혼돈운동이다. Elastica가 굽힘 3차 고유진동수 근방의 주파수로 비틀림 하중을 받을 때의 정확한 이론적 해석을 위해서는 굽힘 3차모드 까지는 반영할 수 있는 식이 모델링 되어야 할 것으로 보인다. 이것은 복잡한 비평면운동을 할 때 굽힘 3차 모드까지 관찰된다는 사실에 근거한다.

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Buckling oad and Post-buckling Behavior of Tapered Column with Constant Volume and Both Clamped Ends (일정체적 양단고정 변단면 기둥의 좌굴하중 및 후좌굴 거동)

  • 이병구
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.41 no.5
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    • pp.112-122
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    • 1999
  • 이 논문은 일정체적을 갖는 양단고정 변단면 기둥의 좌굴하중 및 후좌굴 거동에 관한 연구이다. 기둥의 변단면으로는 직선형, 포물선형, 정현의 선형을 갖는세 가지 변단면을 채택하였다. Bernoulli-Euler 보 이론을 이용하여 압축하중이 작용하여 좌굴된 기둥이 정확탄성곡선을 지배하는 미분방정식을 유도하였다. 유도된 미분방정식을 Runge-Kutta 법과 REgula-Falsi법을 이용하여 수치해석하였다. 수치해석의 결과로 좌굴하중, 좌굴기둥의 평형경로 및 정확탄성곡선을 산출하였다. 또한 좌굴하중-단면비 곡선으로부터 최강기둥의 좌굴하중과 단면비를 산출하였다.

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