• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.4
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• pp.361-368
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• 2015

Recently, the earthquake has been increasing a lot, damage of electric power facility has been serious as well. Nowadays, the importance of pipe support system such as Hanger, Brace, Snubber connecting the main structure have been emphasized. These devices can prevent pipe from damage so that reduce the vibration and shock acting on the pipe. For this reason, the FCD(Friction Concave Damper) was developed and has been expected to reduce the vibration on the pipe through the Friction Pendulum System. This paper was described the introduction of self-developed mechanical damper using the friction pendulum principle and the characteristic test was performed to verify the performance of the device. Additionally the test results have been compared with predicted F.A.P(FCD Analysis Program-self developed) results. As a result, reliability of design could be improved.

• The Journal of the Korea Contents Association
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• v.21 no.9
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• pp.136-148
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• 2021

In this study, the theoretical principle and structural practice of Estill Voice Training model that enables independent control of voice organs in the actor's acting art using voice as a medium of artistic expression. Its purpose is to explore the positive utility that can be applied to operation. The research on the speech science methodology that controls the differences in speech output due to the principle of the generation organ is a reality that has not been actively introduced in Korea compared to the existing actor's speech training that encompasses both the mind and the body. Voice can guarantee the accuracy and stability of operation when an understanding of our body is preceded based on anatomical physiology as well as contribute to the characterization of the character's phonetic character an element of character creation. Considering the training model through proprioception in actor voice training has practical value and alternative significance that the actor can be sought as a principle and practical methodology in the process of generating a series of target sounds.

• Journal of Biomedical Engineering Research
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• v.13 no.3
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• pp.235-244
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• 1992

In this paper, fluttering behavior of mechanical monoleaflet tilting disc heart valve prostheses during the opening phase was analyzed taking into consideration the impact between the occluder and the guiding strut at the fully open position. The motion of the valve occluder was modeled as a rotating system, and equations were derived by employing the moment equilibrium principle. Forces due to lift, drag, gravity and buoyancy were considered as external forces acting on the occluder. The 4th order Runge-Kutta method was used to solve the governing equations. The results iimonstrated that the occludes reaches steady equilibrium position only after damped vibration. Fluttering frequency varies as a function of time after opening and is in the range of 8-84 Hz. Valve opening appears to be affected by the orientation of the valve relative to gravitational force. The opening velocities are in the range of 0.65-1.42m/sec and the dynamic loads by impact of the occludes and the strut are in the range of 90-190 N.

• Korea-Australia Rheology Journal
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• v.14 no.1
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• pp.17-23
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• 2002

A novel and simple method using a cylindrical penetrometer is being developed for the measurement of yield stress. The principle of this technique is based on the measurement of the static equilibrium of a falling penetrometer in a yield stress fluid. The yield stress is simply determined by a balance of forces acting on the penetrometer. The yield stress of Carbopol gels and $TiO_2$ suspensions has been measured using this method. The results are in reasonable agreement with the values from conventional methods. The effects of the dimensions and weight of the penetrometer have been examined. The long-term behaviour was also observed. No measurable creep was seen and equilibrium was found to be very quickly established. The cylindrical penetrometer technique promises to be a simple, quick and reliable static method for the measurement of yield stress.

• Journal of Korean Theatre Studies Association
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• no.48
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• pp.385-419
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• 2012

Son Jinchaek got into his directing career since 1976 when he founded the theatre group Minye with Huhgyu and others. His experience in Minye was the turnaround of his life; Huhgyu was a teacher in his artist's life whereas Brecht was a teacher for his ideology to make 'Korean Theatre'. From these two teachers, he learned how and why Korean Theatre should be made. Since then, Korean theatre was his calling for 40 years of his directing career. As he established Michoo in 1986, it served a turning point in his art. His focus was on intrinsic attributes of Korean Theatre with Madang Jungshin. With Madang Jungshin, he tried to get over the former generation's fixation on external materials of Korean traditional theatre and folk culture to make Korean Theatre. Rather, he believed Korean Theatre could be realized when it grafted Korean social reality onto the stage, while the form was subsequent. He advocated Korean Theatre should mirror present social reality and circulate social energy. Also, he did not give up aesthetics. On the contrary, his aesthetic style was conspicuously evident in his productions. In spite of his life long career with noteworthy works, the critical discourses are strikingly scarce especially when compared with other senior and peer directors such as Hugh Gyu, Ahn Minsoo, Oh Taesok, and Lee Yoontaek. During his career he has crossed into various genres from Changeuk, Madangnori, and to theatres, which were too versatile to thread them into a discourse and caused a lack of theoretical greeting. Madangnori has anchored its artistic structure on its polished aesthetics which were acclaimed by the general audience for 30 years. For theatre, he concentrated on one production per year to grasp its own style. Theatre works also had revealed his own style of being opened and of being emptied which was certainly different from Madangnori, but had same aesthetic principle within it. This paper attempts to recompose his stylistic features with 'Madang aesthetics' which were based on open space, open acting style, and graphic ensemble. This paper tries to demonstrate how his 'Madang aesthetics' has refined his productions in scenography, acting style, and in more like metaphoric and metonymic symbolic expression of the graphic ensemble. To do this, two productions were explored: eLee Chunpoongjeun and Yulha Ilgyee Manbo. Madangnori was sorely explored by Son Jinchaek with his artistic colleagues Yoon Munshik, Kim Jongyeup, Kim Sungnyu, music designer Park Buhmhoon, and choreographer Guk Sooho. Though it has been ignored for its popular appeal by the doctrinaire theoretical opinions, it started to pull academic attention recently. His theatres are also getting sharp with his 'Madang aesthetics' as well as minimalistic expression in scenography, acting style, and graphic ensemble. Madang Jungshin is the soul and Madang aesthetics is the body in his artistic works. The Madang Jungshin animates the Madang aesthetics, so they become alive in his theatre.

• Structural Engineering and Mechanics
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• v.37 no.4
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• pp.401-413
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• 2011

The aerodynamic stability of orthotropic tensioned membrane structures with rectangular plane is theoretically studied under the uniform ideal potential flow. The aerodynamic force acting on the membrane surface is determined by the potential flow theory in fluid mechanics and the thin airfoil theory in aerodynamics. Then, based on the large amplitude theory and the D'Alembert's principle, the interaction governing equation of wind-structure is established. Under the circumstances of single mode response, the Bubnov-Galerkin approximate method is applied to transform the complicated interaction equation into a system of second order nonlinear differential equation with constant coefficients. Through judging the stability of the system characteristic equation, the critical divergence instability wind velocity is determined. Finally, from different parametric analysis, we can conclude that it has positive significance to consider the characteristics of orthotropic and large amplitude for preventing the instability destruction of structures.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.8
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• pp.873-878
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• 2012

Putting a conductive rod between rotating axial electrodynamic wheels composed of repetitive permanent magnets, three-axial magnetic forces generate on the conductive rod. It is possible to levitate and transfer the rod on space with the forces. However, the forces vary in direction and magnitude for a position of the rod between the electrodynamic wheels. Thus, the position influences the stability of the rod also. To guarantee the stability of a levitated object, the force acting on the object should have negative stiffness like a spring. So, we analyze the stable operating range of the conductive rod levitated by the axial wheels with the commercial finite element tool in this paper. Specially, as the pole number and the radial width of permanent magnets has much influence on the generated force and thereby the stable region, their sensitivities are analyzed also. The analytic result is compared with experimental result.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.169-176
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• 1998

A method for the dynamic analysis of multibody systems undertaking impulsive force is introduced in this paper. A partial velocity matrix based on Kane's method is introduced to reduce the number of equations to be solved. Only minimum number of equations of motion can be obtained by using the partial velocity matrix. This reduces the computational effort significantly to obtain the dynamic response of the system. At the very moment of the impulse, instead of using the numerical integrator to solve the equations of motion, the impulse and momentum principle is used to obtain the dynamic response. The impulse as wall as the reaction force acting on the kinematic joints can easily calculated too.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.76-80
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• 2011

This paper proposes a method to calculate magnetostrictive forces, displacement, and vibration modes of a large-scale Brushless DC(BLDC) motor by using a magneto-mechanically strong coupling formulation. The force is calculated using the energy method with magnetostrictive stress tensor. The mechanical vibration modes are also analyzed by using the principle of Hamilton and the calculated magneto-elastic forces acting on the surfaces of the stator. To verify the algorithm, 3 MW BLDC motor is simulated, and the forces, displacements, and vibration modes are calculated. The result shows that the mechanically stressed core has more deformation or displacements than those of the normal condition.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.115-116
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• 2002

This study aimed to investigate flow measurement by using a 'bucket and stop-watch' method of flow measurement. Most flow measurement systems measure pressure or other fluid properties to infer flow rate, though time is a variable which can be easily and very accurately measured. The main principle behind the method was to fill up a reservoir until a set pressure had been reached. This reservoir would then be emptied and the cycle would repeat itself. The prototype was designed to control flow rate using the method. It made use of computer control with an analogue digital converter and fast acting solenoid valves which controlled the flow into a reservoir. Reservoirs were available with internal diameter of 1mm up to 5.5mm to cope with a range of flow rate.