• Journal of KSNVE
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• v.7 no.3
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• pp.439-447
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• 1997

In this study, the dynamic instabilities of a nonlinear elastic system subjected to follower forces are investigated. The two-degree-of-freedom double pendulum model with nonlinear geometry, cubic spring, and linear viscous damping is used for the study. The constant, the initial impact forces acting at the end of the model are considered. The chaotic nature of the system is identified using the standard methods, such as time histories, power density spectrum, and Poincare maps. The responses are chaotic and unpredictable due to the sensitivity to initial conditions. The sensitivities to parameters, such as geometric initial imperfections, magnitude of follower force, direction control constant, and viscous damping, etc., are analysed. Dynamic buckling loads are computed for various parameters, where the loads are changed drastically for the small change of parameters.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.87-92
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• 2016

Van der Pol's oscillators is non-conservative oscillator that having nonlinear damping phenomena. The energy of its system is dissipative at a high amplitude whereas its system creates the energy at low amplitude. In order to identify another behaviors in the Van der Pol oscillator, the periodic external force applied in the Van der Pol oscillator. This paper confirms the pattern of variation for the limit cycle according to parameter variation in order to identify another behaviors in the Van der Pol oscillator.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.353.2-353
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• 2002

The attenuation of waves transmitted through non-conservative joints that are shown in many practical structures, is affected by the impedance and the orientation of the joint. In this paper, the joints between plate structures are assumed to be modeled as linear spring-dashpot systems and the transmission and reflection of vibration energy in the medium to high frequency ranges are investigated. (omitted)

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.985-991
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• 2006

For a shear-deformable beam-column element subjected to non-conservative forces. equations of motion and a finite element formulation are presented applying extended Hamilton's principle. The influence of non-conservative force's direction parameter. internal and external damping forces, and shear deformation and rotary inertia effects on divergence and flutter loads of Beck's columns are intensively investigated based on element stiffness. damping and mass matrixes derived for the non-conservative system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.244-251
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• 2002

The purpose of this paper is to investigate the stability of tapered columns with general boundary condition(translational and rotational elastic support) at one end and carrying a tip mass of rotatory inertia with translational elastic support at the other end. The column model is based on the classical Bernoulli-Euler beam theory which neglects the effects of rotatory inertia and shear deformation. The governing differential equation for the free vibrations of linearly tapered columns subjected to a subtangential follower force is solved numerically using the corresponding boundary conditions. And the bisection method is used to calculate the critical divergence/flutter load. After having verified the results of the present study, the frequency and critical divergence/flutter load are presented as functions of various nondimensional system parameters.

• Journal of Power System Engineering
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• v.4 no.4
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• pp.65-69
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• 2000

On the dynamic behavior of a simple beam subjected to an uniformly distributed tangential follower force, the influences of the velocities and magnitudes of a moving mass have been studied by numerical method. The instant amplitude of a simple beam is calculated and analyzed for each position of the moving mass represented by the time functions. The uniformly distributed tangential follower force is considered within its critical value of a simple beam, and four values of velocity is also chosen. Their coupling effects on the deflections of a simple beam are inspected too. When a moving mass moves after middle zone of a simple beam at the low velocities, its deflection is increased by the coupling of an uniformly distributed tangential follower force and moving mass.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.2
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• pp.183-187
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• 1986

An experimental method to give a tangential follower force to a cantilever beam having a concentrated tip mass by the magnetic force of the electromagnet has been described. The dynamic behaviour of the beam under this nonconservative load has been analysed by experimentally as well as by theoretically. The theoretical and experimental results on the natural frequencies and the critical force of the systems are in good agreement with each other.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.441-452
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• 2012

Most of signs and symptoms of temporomandibular disorder(TMD) is temporary and self-limiting as other musculoskeletal diseases. Conservative, reversible treatment; self care, behavior modification, physical therapy, pharmacotherapy, splint therapy should be considered as initial treatment for temporomandibular disorder rather than non conservative, irreversible treatment.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.207-207
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• 2020

하천으로 유입된 오염물질의 거동을 정확하게 예측하는 것은 하천 시스템의 수질 유지관리에 매우 중요하다. 본 연구에서는 1차 감쇠율(decay rate)을 가진 비보존성 오염물의 비정상 이송해석 방정식의 해를 위해 유한체적기법이 개발되어졌다. 하천 흐름 해석을 위해 자연형 단면에서의 마름-젖음 해석이 가능한 기법이 도입되었다. 이 기법은 2차-정도의 정확성와 Courant 수가 1 까지 안정함을 보장한다. 도입된 기법은 Godnov 형의 유한체적기법을 이용하여 St. Venant 방정식들을 해석하였고 질량 및 운동량 플럭스는 Roe 형의 Riemann Solver 를 사용하여 연산하였다. 오염물의 이송 해석은 추가적인 이송-확산 방정식을 도입을 통해 기존의 St. Venant 방정식과 함께 풀려질 수 있다. 추가된 방정식과 St. Venant 식은 3×3 eigenstructure를 구성하였고 이는 2차원 흐름해석 기법과 유사하게 해석될 수 있었다. 본 연구 모형의 검증을 위해 오염물의 계속적 주입을 가정한 가상 및 실제 하천에 적용되었다. 연구된 기법은 모든 적용에서 합리적 정확도를 가지고 오염물질의 연속적인 특성을 잘 모의하고 있었다.

• Journal of Wetlands Research
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• v.21 no.2
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• pp.102-113
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• 2019

Slack-tide sampling was carried out at 6 stations at high and low tide for a tidal cycle during spring tide of the early summer (June) and summer (July, August) of 2016 to determine the difference of water quality according to tide in Masan Bay, Korea. The mixing regime of all the water quality components investigated was well explained through the correlation with SAL. In the early summer and summer, TURB, DSi and NNN which mainly flow into the bay from the streams and SS, COD, AMN and $H_2S$ which mainly indicate the internal sink and source materials have a property of conservative mixing and non-conservative mixing, respectively. The conservative mixing showed a good linear relationship of the water quality between high and low tide, and the non-conservative mixing showed a variation of different pattern each other. Factor analysis performed on the concentration difference data sets between high and low tide helped in identifying the principal latent variables for them. In early summer, multiple effects (tidal action, natural influx and internal sinks and sources etc.) acted in combination for the differences to be distributed evenly in four factors (VF1~4), since there were few allochthonous inputs as a low-water season. On the contrary, in summer, the parameters showing large concentration difference at ST-1 affected by stream water were concentrated in one factor (VF1) and clearly distinguished from the parameters affected by the internal sinks and sources. In fact, there is no estuary (bay) that always maintains steady state flow conditions. The mixing regime of an estuary might be changed at any time due to the change of flushing time, and furthermore the change of end-member conditions due to the internal sinks and sources makes the occurrence of concentration difference inevitable. Therefore, when investigating the water quality of the estuary, it is necessary to take a sampling method considering the tide to obtain average water quality data.