• Proceedings of the KSR Conference
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• 1998.11a
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• pp.445-452
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• 1998

The dynamic performance design of catenary-pantograph system which collects current for the next generation Korean high speed train(KHST) was considered. Used was the same dynamic model of the catenary-pantograph system as that of TGV-K which will be introduced for Kyung-bu corridor. Using the model , sensitivity analysis fer design variables were made to improve dynamic performance of KHST system. The results of sensitivity analysis and performance improvement are as follows: (1) It was found that aerodynamic force, tension of contact wire, mass of contact strip, mass of supporting contact strip, mass of clamp, mass of steady arm, and stiffness of plunger were the design variables most influencing the dynamic performance of the system. (2) Pantograph with reductions of 20% aerodynamic force, 34% weight of supporting contact strip, 20% spring constant of plunger, and 34% equivalent mass of steady arm was very possible system for the KHST which will be running at maximum operating speed 350 km/h.

• Korean Institute of Interior Design Journal
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• no.28
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• pp.265-265
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• 2001

The perceptual presentation of interior design is to represent an interior space planned by a designer as if people see it in reality. The perceptual presentation methods that have developed are perspectives, full-scale models, small-scale models, photography of models, video taping of models, computer images, computer animation, and virtual reality. The purpose of this study is to investigate limits of those perceptual presentation methods according to their characteristics. The methods have characteristics that are either static or dynamic and either monoscopic or stereoscopic. In terms of representing interior spaces and perceiving interior spaces, the dynamic characteristic is more helpful than the static characteristic because the dynamic characteristic provides consecutively changing views of interior spaces when people walk around within the spaces. The stereoscopic characteristic is more helpful than the monoscopic characteristic because the stereoscopic characteristic provides the binocular depth perception. Full-scale models, small-scale models, virtual reality that have dynamic and stereoscopic characteristics, are most effective. The next effective methods are video taping of models and computer animation that have dynamic and monoscopic characteristics. The last effective methods are perspectives and photography of models that have static and monoscopic characteristics. But the most effective methods can not be said that those are perfect because each of them still has limits. Designers have to consider the limits of each perceptual presentation method to find a way that shows their designs most effectively. To develop the perceptual presentation methods of interior design, researchers should focus on the helpful characteristics that are dynamic and stereoscopic.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.4
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• pp.508-519
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• 2018

In order to design the hull form of an underwater vehicle in the conceptual design phase, the dynamic characteristics depending on the hull form parameters should be identified. Course-keeping stability, turning ability, yaw-checking ability, and mission competence are set to be the indices of the dynamic characteristics, and the geometric parameters for the bare hull and rudder are set to be the hull form design parameters. The total sensitivity of the dynamic characteristics with respect to the hull form parameters is calculated by the chain rule of the partial sensitivity of the dynamic characteristics with respect to the hydrodynamic coefficients, and the partial sensitivity of the hydrodynamic coefficients with respect to the hull form parameters. Based on the sensitivity analysis, important hull form parameters are selected, and those optimal values to satisfy the required intercept time of mission competence of a specific underwater vehicle and turning rate are estimated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.10
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• pp.882-889
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• 2008

A humanoid is a robot with its overall appearance based on that of the human body. When the humanoid moves or walks, dynamic forces act on the body structure. Although the humanoid keeps the balance by using a precise control, the dynamic forces generate unexpected deformation or vibration and cause difficulties on the control. Generally, the structure of the humanoid is designed by the designer's experience and intuition. Then the structure can be excessively heavy or fragile. A humanoid design scenario for a systematic design is proposed to reduce the weight of the structure while sufficient strength is kept. Lower parts of the humanoid are selected to apply the proposed design scenario. Multi-body dynamics is employed to calculate the external dynamic forces on the parts and structural optimization is carried out to design the lower parts. Because structural optimization using dynamic forces directly is fairly difficult, linear dynamic response structural optimization using equivalent static loads is utilized. Topology and shape optimizations are adopted for two steps of initial and detailed designs, respectively. Various commercial software systems are used for analysis and optimization. Improved designs are obtained and the design results are discussed.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.4
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• pp.307-314
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• 2016

Recently, demands on the tapping machine are increased due to the case of a cell phone is changed to metal such as aluminum. The automatic tool changer (ATC) is one of the most important devices for the tapping machine related to the speed and energy consumption of the machine. To reduce the consumed energy and vibration, the dynamic modeling is essential for the ATC. In this paper, inverse dynamic modeling of a novel ATC mechanism is introduced. The proposed ATC mechanism is composed of a double four-bar mechanism with a circular tablet to generate continuous rotation of the tablet. The dynamic modeling is performed based on the Lagrange equation with a modeling for the contact between the four-bar and the tablet. Simulation results for various working conditions are proposed and analyzed for the prototype design. The dynamic modeling can be applied to determine the proper actuator and to reduce the vibration and consumed energy for the ATC machine.

• Korean Institute of Interior Design Journal
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• no.29
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• pp.265-272
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• 2001

The perceptual presentation of interior design is to represent an interior space planned by a designer as if people see it in reality. The perceptual presentation methods that have developed are perspectives, full-scathe models, small-scale models, photography of models, video taping of models, computer images, computer animation, and virtual reality. The purpose of this study is to investigate limits of those perceptual presentation methods according to their characteristics. The methods have characteristics that are either static or dynamic and either monoscopic or stereoscopic. In terms of representing interior spaces and perceiving interior spaces, the dynamic characteristic is more helpful than the static characteristic because the dynamic characteristic provides consecutively changing views of interior spaces when people walk around within the spaces. The stereoscopic characteristic is more helpful than the monoscopic characteristic because the stereoscopic characteristic provides the binocular depth perception. Full-scale models, small-scale models, virtual reality that have dynamic and stereoscopic characteristics, are most effective. The next effective methods are video taping of models and computer animation that have dynamic and monoscopic characteristics. The last effective methods are perspectives and photography each of models that haute static and monoscopic characteristics. But the most effective methods can nut be said that those are perfect because each of them still has limits. Designers have to consider the limits of each perceptual presentation method to find a way that shows their designs most effectively. To develop the perceptual presentation methods of interior design, researchers should focus on the helpful characteristics that are dynamic and stereoscopic.

• International Journal of Railway
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• v.4 no.2
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• pp.50-55
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• 2011

The dynamic stability of railway vehicle has long been one of the important issues in railway safety. The dynamic simulator has been used as a tool for investigating the dynamic stability of railway vehicles and wheel/rail interfaces. In particular, small scale simulators have been widely used in laboratory studies instead of full scale roller rigs which can be quite costly and rather inconvenient for testing out the effect of diverse design parameters. But techniques for design of a small scale simulator for the fundamental study about the dynamic characteristics of the wheel-rail systems and the bogie systems have not been well developed in Korea. Therefore, a research on the development of a small scale simulator for investigating bogie dynamics needs to be undertaken. The present paper investigates design of a small-scaled derailment simulator and the design of a small scale bogie. The simulator developed can be used to investigate the effect of diverse parameters such as attack angle, wheelbase and cant on dynamic behavior of the bogie and key dynamic performance parameters such as derailment coefficient and critical speed.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.397-401
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• 2008

Knowledge of dynamic characteristics of structural elements often can make difference between success and failure in the design of structure due to resonance effect. In this paper an analytical model of a cantilever beam having midpoint load is considered for structural optimization. This involves creating the geometry which allows parametric study of all design variables. For that purpose optimization of cantilever beam is elaborated in order to find the optimum geometry which minimizes its volume eventually for minimum weight using ANSYS. But such geometry could be obtained by different combinations of width and height, so that it may have the same cross sectional area yet different dynamic behavior. So for optimum safe design, besides minimum volume it should have minimum vibration as well. In order to predict vibration different dynamic analyses are performed simultaneously to solve the eigenvalues problem assuming no damping initially through MATLAB simulations using state space form for modal analysis, which identifies the resonant frequencies and mode shapes belonging to the lowest three modes of vibration. And next by introducing damping effects tip displacement, bending stress and the vertical reaction force at the fixed end is evaluated under some dynamic load of varying frequency, and finally it is discussed how resonance can be avoided for particular design. Investigation of results clearly shows that only structural analysis is not enough to predict the optimum values of dimension for safe design. Potentially this technique will meet maintenance and cost goals of many organizations particularly for the application where dynamic loading is invertible and helps a lot ensuring that the proposed design will be safe for both static and dynamic conditions.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.195-212
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• 2022

Based on the kinetic typography principle and the structure features of Chinese characters, this study took the Chinese'24 solar terms' theme dynamic poster as the research object, explored the visual expression of dynamic Chinese characters, and tried to summarize the visual expression law of Chinese characters in dynamic poster design. It can be found that, there could be 6 different types of Chinese character expressions in the 24 solar terms poster design. Among them, 'Drawing' design method has the meaning of text structure and form expression, and 'Assembling' design method has the meaning of text stroke and texture association, also, 'Forming' design method bring its meaning through stroke deformation, 'Transforming' design method conveys the content through text disintegration, 'Replacing' design method mainly bring the meaning through simulation, while 'Rotation' design method always express through visual three-dimensional and space. Finally, the findings could not only provide analytical logic and methods for the expression of Chinese characters in dynamic poster design, but also fill the lack of formative research on dynamic Chinese characters, which hopefully provide basic information for the research related to dynamic Chinese character structure, as well as the dynamic poster designers.

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.10a
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• pp.48-49
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• 2005