• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1244-1254
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• 1992

This paper investigates the vibrational damping characteristics of laminated plates composed of elastic, viscoelastic and elastic layers by theoretical and experimental methods. Laminated plates are in cylindrical bending and visco-elastic adhesive layer is assumed as the visco-elastic spring which takes damping effect through both shear and normal deformations. Governing equations oof laminated plates are derived in the form of simultaneous first order differential equations, which account for the longitudinal displacements, rotary inertia and shear deformations of elastic base plate and elastic constraining plate. The numerical calculations of the equations are illustrated by the applications to the cantilever beam in transverse vibration. The results of the solutions agree well with the experimental measurements in general. The damping effects due to the shear and thickness deformations in the adhesives are analyzed and it is shown that for thicker adhesives, the damping effect due to thickness deformation becomes significant and for thinner adhesives, due to shear deformation.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.395-406
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• 2011

In this research a numerical simulation method is developed for moving body in free surface flows using fixed staggered rectangular grid system. The non-linear free surface near the body is defined by marker-density method. The body boundary is defined by line segment connecting the points where the body surface and grid line meet. Continuity equation and Navier-Stokes equations are used as governing equations and the equations are coupled with two-step projection method. The velocities and pressures of body boundary and free surface cells are calculated with simultaneous iterative method. To treat a body movement in a fixed grid system, the volume displaced by moving body is added to the divergence of the body boundary cell. For the verification of the present numerical method. vortex shedding period of advancing cylinder is calculated and the period is compared with existing experiment results. Moreover, added mass and damping coefficients of a vertically excited box are calculated and the computed results are compared with published experiment results. Impulsive pressure and water level variation due to sloshing phenomenon are simulated and the results are compared with published experiment results. Varying the plunger shape, the waves generated by plunging type wave maker are compared with the 2nd order Stokes wave theory The plunger shape generating the wave that shows the best agreement with the theory is represented.

• Proceedings of the Korea Association of Information Systems Conference
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• 1996.11a
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• pp.199-204
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• 1996

It is discussed how to determine the home location of idle vehicles in an AGVS with a loop guide path in a way of maximizing the request-call response probabilities for all demand. Optimal home position is selected by solving the simultaneous equations easily. Static positioning strategy is analyzed in which a single home position is allocated to which every vehicle is routed whenever it becomes idle. The cases of unidirectional guidepath is considered only. We provide a numerical example to illustrate the search algorithm developed for the case and compare the searched optimal solutions with the others.

• Journal of the Korean Mathematical Society
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• v.42 no.5
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• pp.893-912
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• 2005

We discuss a certain geometric property $X_{{\theta},{\gamma}}$ of dual algebras generated by a polynomially bounded operator and property ($\mathbb{A}_{N_0,N_0}$; these are central to the study of $N_{0}\timesN_{0}$-systems of simultaneous equations of weak$^{*}$-continuous linear functionals on a dual algebra. In particular, we prove that if T $\in$ $\mathbb{A}$$^{M}$ satisfies a certain sequential property, then T $\in$ $\mathbb{A}^{M}_{N_0}(H) if and only if the algebra $A_{T}$ has property $X_{0, 1/M}$, which is an improvement of Li-Pearcy theorem in [8].

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.3 no.2
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• pp.16-21
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• 1992

The TE-mode characteristics of scattering and reception by a flanged parallel-plate waveguide are examined. The technique of the Fourier transform is used to represent the scattered fields in the spectral domain. The simultaneous equations for the transmitted field coefficients are solved to obtain the solution in an asymptotic series form. The numerical computations are performed to illustrate the behaviors of the scattered field and the transmission coefficients versus the aperture size.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.9
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• pp.461-466
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• 2005

This paper addresses the bidding strategies of a hydro generator in an electricity market, and their effect on the electricity market in accordance with some parameters: the water volume, the demand elasticity, and the hydro unit performance. The competition of a hydro generator is formulated as a hi-level optimization problem, and the solving scheme for the equilibrium condition is proposed as a set of nonlinear simultaneous equations. The equilibrium of the oligopolistic model is evaluated by comparison with that of a perfect competition model from the viewpoint of a market power. Simulation results show some parameters have an influence on the market power of an electricity market including a hydro generator.

• 전기의세계
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• v.17 no.2
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• pp.11-15
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• 1968

One of the most important methods used in the modern analysis of linear networks and systems is the signal flow graph technique, first introduced by S.J. Mason in 1953. In essence, the signal-flow graph technique is a graphical method of solving a set of simultaneous. It can, therefore, be regarded as an alternative to the substitution method or the conventional matrix method. Since a flow-graph is the pictorial representation of a set of equations, it has an obvious advantage, i.e., it describes the flow of signals from one point of a system to another. Thus it provides cause-and-effect relationship between signals. And it often significantly reduces the work involved, and also yields an easy, systematic manipulation of variables of interest. Mason's formula is very powerful, but it is applicable only when the desired quantity is the transmission gain between the source node and sink node. In this paper, author summarizes the signal-flow graph technique, and stipulates three rules for conversion of an arbitrary nonsource node into a source node. Then heuses the conversion rules to obtain various quantities, i.e., networks gains, functions and parameters, through simple graphical manipulations.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.4
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• pp.118-123
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• 1997

The study suggests a method to analyze the vibration of the multi-stepped beam having the different circular cross-sections. The rotatory inertia, the shear deformation and the torque applied at both ends of the beam are considered in the governing equation. The complex displacement and the variable separation are introduced to derive the solution of the equation of each uniform beam element having constant cross-section. Then boundary conditions are applied to solve the total system. This method uses the mathematically exact solutions unlike numerical method such as the finite element method in solving the problem having the simultaneous differential equations of Timoshenko beam theory. the natural frequencies and the corresponding mode shapes are precise, especially the mode shapes are continuous.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1992.03a
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• pp.11-26
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• 1992

In this research, a numerical algorithm has been developed, which can be applied to the large deformation and large displacement contact problems between angle change have been proposed considering the change in geometric shape and rate of contact force. A set of linear simultaneous equations is constructed by adding the geometric shape change and contact conditions to the original stiffness matrix. A new method to determine time increment has been proposed based on Euler method, in which the condition to prevent the contact bodies from penetrating and overrunning each other has been taken into consideration. Practical application to contact problem is extrusion in which bodies are sliding along the contact boundary.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.682-686
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• 1991

The purpose of a solar tracking system (STS) is to control the attitude of a space vehicle so that it will track the sun with high accuracy. In this paper, the literature of tracking of the sun in a plane is surveyed and a control modeling for the analysis of STS is presented by simultaneous transfer functions and state-space equations. Also a program for obtaining state variables by the single term Walsh series(STWS) approach is developed. The proposed approach is much simpler in analysis and easier in implementation than the Runge-Kutta numerical integration Method. The results of computer simulation are shown for the dynamic behaviors of vehicle axis, armature-controlled dc motor and controller of STS via a Runge-Kutta method and a single term Walsh series approach, respectively.