• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.152.3-152
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• 2001

This paper describes an application of an air-pulse actuator for vibration control of a framed structure. Dynamic characteristics of the prototype actuator that utilizes an air-jet reaction force pulsated by an electromagnetic valve were investigated to use it as a control actuator. Using a control law based on the sliding mode control theory, experiments of the vibration control were carried out. The experimental results verified the validity of the actuator performance.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.4
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• pp.240-251
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• 1987

In this paper, with the end effect taken into consideration, the fundamental characteristics of a linear induction motor-the eddy currents of the secondary conducting sheet (traveller), the flux density in the air gap-are analysed by means of electromagnetic field theory. Accordingly, the derived governing eqations of the chatacteristics with goodness factor, presents that it was possible not only to predict the performance characteristics, but to obtain the data that needs to optimize a design of a motor with the reduction of the end effect.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.37-40
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• 1987

In transverse flux linear induction motors(TFLIM), The loops of the working flux lie in planes transverse to the direction of motion. With a poly-phase primary winding, The TFLIMs has both electro-magnetic propulsion and levitation force. Thus, TFLIM a will be useful in high speed ground transportation systems. In this paper, The characteristics of a single aide TFLIM are analysed by using electromagnetic field theory.

• 전기의세계
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• v.31 no.4
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• pp.288-295
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• 1982

In this study, the characteristic equation of a double sided short stator linear induction motor, referred to as LIM excited by equivalent current sheet having linear current density was derived using Maxwell's electromagnetic field theory with its entry and exit, end effects taken into consideration. According to the treatment of several physical phenomena in the air-gap i.e. the magnetic flux density distributions, thrust-force, forward and backward travelling wave with decay, normal field, the fundamental data in this study are made reference to improve the characteristics of LIM, effectual electro-magnetic energy conversion devices.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.158-161
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• 2005

The fiber-reinforced composite materials have been advanced for various applications because of its excellent mechanical and electromagnetic properties. On their manufacturing processes, however, thermo-curing inherently produces the undesired thermal deformation mainly from temperature drop from the process temperature to the room temperature, so called spring-back. The spring-back must be removed to keep the precision of designed shape. In this research, the spring-back of {glass fiber / epoxy}+{carbon fiber / epoxy} unsymmetric hybrid composites were predicted using Classical Lamination Theory (CLT), and compared with the experimental data. Additionally, using finite element analysis (ANSYS), the predicted data and experimental data were compared. The predicted values by CLT and ANSYS were well matched with experimental data.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.2123-2138
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• 1994

A study on the dynamic mechanical properties of the high strength carbon fiber epoxy composite beam was carried out. The macromechanical model was used for the theoretical analysis of the symmetric laminated composite beam. The anisotropic plate theory and Bernoulli-Euler beam theory were used to predict the effective flexural elastic modulus and the specific damping capacity of laminated composite beam. The free flexural vibration and torsional vibration tests were carried out to determine the specific damping capacities of the unidirectional laminated composite beam. The vibration tests were performed in a vacuum chamber with laser vibrometer system and electromagnetic hammer to obtain accurate experimental data. From the computational and experimental results, it was found that the theoretical values with the macromechanical analysis and the experimental data of symmetric laminated composite beam were in good agreement.

• Journal of Acupuncture Research
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• v.37 no.4
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• pp.241-246
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• 2020

The intelligent tissue theory states that organ information is conveyed on electromagnetic waves and these are interpreted by bodily tissue, so that real-time organ states are reflected in the tissue at each organ's related meridian. This article describes the practical implications of this, how this relates to acupuncture, and how it accounts for the common acupuncture-related phenomena. The Chinese medicine notion of "chi" is also explored. Its history is described, including the 1970's reinterpretation. This article suggests that both the Nei Jing and also the 1970's model of how acupuncture works are merely metaphorical; do not describe reality; and that "chi" (which is central to these models) does not really exist. Alternative explanations are provided for all the common phenomena that are usually attributed to "chi", and a simple account of how acupuncture works is given.

• Wind and Structures
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• v.7 no.3
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• pp.187-202
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• 2004

Wind tunnel experiments are often performed for the identification of aeroelastic parameters known as flutter derivatives that are necessary for the prediction of flutter instability for flexible structures. Experimental determination of all the eighteen flutter derivatives for a section model facilitates complete understanding of the physical mechanism of flutter. However, work in the field of identifying all the eighteen flutter derivatives using section models with all three degree-of-freedom (DOF) has been limited. In the current paper, all eighteen flutter derivatives for a streamlined bridge deck and an airfoil section model were identified by using a new system identification technique, namely, Iterative Least Squares (ILS) approach. Flutter derivatives of the current bridge and the Tsurumi bridge are compared. Flutter derivatives related to the lateral DOF have been emphasized. Pseudo-steady theory for predicting some of the flutter derivatives is verified by comparing with experimental data. The three-DOF suspension system and the electromagnetic system for providing the initial conditions for free-vibration of the section model are also discussed.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.1
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• pp.23-31
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• 2003

A novel 3D shape optimization algorithm is presented for electromagnetic devices carry-ing eddy current. The algorithm integrates the 3D finite element performance analysis and the steepest descent method with design sensitivity and mesh relocation method. For the design sensitivity formula, the adjoint variable vector is defined in complex form based on the 3D finite element method for eddy current problems. A new 3D mesh relocation method is also proposed using the deformation theory of the elastic body under stress to renew the mesh as the shape changes. The design sensitivity f3r the sur-face nodal points is also systematically converted into that for the design variables for the parameterized optimization application. The proposed algorithm is applied to the optimum design of the tank shield model of the transformer and the effectiveness is proved.

• Proceedings of the KIEE Conference
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• 2000.07e
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• pp.152-156
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• 2000

A Switched Reluctance Motor(SRM) has been widely studied for practical use due to recent development on technology of power electronics. Because of its advantage that are high speed driving, simple structure and easy variable-speed control, it is expected for applications to automo biles and others. However, it has some problems that are, for examples, relatively high torque ripples and electromagnetic noise. In this paper, a simple theory is presented to represent characteristic of a SRM and theoretical results are compared with experimental ones. In the theory, the inductance variations of a SRM are approximated as linear and winding resistances and the magnetic saturation are ignored. With these approximations, we derived some equations expressing load characteristics of a SRM. Also, the torque ripple was removed by applying a variable hysteresis band control.