• Proceedings of the KSME Conference
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• 2003.04a
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• pp.868-873
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• 2003

This paper deals with the linear dynamic response of an elastically restrained beam under a moving mass, where the elastic support was modelled by translational springs of variable stiffness. Governing equations of motion taking into account of all inertia effects of the moving mass were derived by Galerkin's mode summation method, and Runge-Kutta integration method was applied to solve the differential equations. The effects of the speed, the magnitude of the moving mass, stiffness and the position of the support springs on the response of the beam have been studied. A variety of numerical results allows us to draw important conclusions for structural design purposes.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.4 s.247
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• pp.314-319
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• 2006

To analyze in-vivo blood flow characteristics in a chicken embryo, in-vivo experiment was carried out using micro-PIV technique. Because endothelial cells in blood vessels are subject to shear stress of blood flow, it is important to get velocity field information of the placental blood flow. Instantaneous velocity fields of an extraembryonic blood vessel using a high-speed camera and intravital microscope. The flow images of RBCs were obtained with a spatial resolution of $20\times20{\mu}m$ in the whole blood vessels. The mean velocity field data confirm that the blood flow does show non-Newtonian fluid characteristic. The blood in a branched vessel merged smoothly without any flow separation into the main blood vessel with the presence of a slight bump. This in-vivo micro-PIV measurement technique can be used as a powerful tool in various blood flow researches.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.8 s.197
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• pp.50-57
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• 2007

In this paper, two types of novel planar Translational Parallel Manipulators (TPMs) by using parallelogram mechanism are conceived. One is made up of two Pa-P (Parallelogram-Prismatic) legs connecting the base to the moving platform. The other consists of two P-Pa legs, which is the kinematic inversion of the former. Since connecting links in a parallelogram mechanism are subject to only tensile/compressive load and all the heavy actuators are mounted at the base, the proposed manipulators can be applied for planar positioning/assembly tasks requiring high stiffness and high speed. The position, velocity, and statics are analyzed, and the design methodology using prescribed workspace and velocity transmission capability is presented. Finally, two types of prototype manipulators have been developed.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1383-1386
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• 1990

Fuzzy theory may be constructed of Fuzzy sets theory, Fuzzy measurement and Appoximate reasoning, and nowadays the reseaches on it are done widely in both theoretical and practical aspects. In this paper, the authors sought for the subject in Hirota's Fuzzy CAI: A decision making simulated fuzzy problem on the speed and accelerator control of a car driven in the high way. Interesting results on these fuzzy solutions of this problem, based on a defuzzification with 9 kinds of the methods, are reported. And the characters of these solutions, linear or nonlinear and their fuzzy control evaluations are stated.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.3
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• pp.283-286
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• 1998

For the systematic study on the resistance characteristics of the planing hull, the experimental studies on the correlation between geometrical characteristics of the subject hull forms and their hydrodynamic characteristics are carried out. This study is the first stage to develop the advanced planing hull type fishing boat and involves the followings; -Resistance characteristics for typical four different section types, -Resistance characteristics for different length-beam ratio

• Steel and Composite Structures
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• v.37 no.1
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• pp.37-49
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• 2020

In this paper, free vibration finite element analysis of axially moving laminated composite beams subjected to axial tension is studied. It is assumed that the beam has a constant axial velocity and is subject to uniform axial tension. The analysis is based on higher-order theories that have been presented by Carrera Unified Formulation (CUF). In the CUF technique, the three dimensional (3D) displacement fields are expressed as the approximation of the arbitrary order of the displacement unknowns over the cross-section. This higher-order expansion is considered in equivalent single layer (ESL) model. The governing equations of motion are obtained via Hamilton's principle. Finally, several numerical examples are presented and the effect of the ply-angle, travelling speed and axial tension on the natural frequencies and beam stability are demonstrated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.7
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• pp.1005-1013
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• 2002

Spin-up is a transient flow phenomenon occurring in a container when it starts to rotate from rest or its rotational speed increases from a low to high value. However, most studies on this subject have been for two-dimensional approximation. In this study, spin-up flows in a shallow rectangular container are analysed by using three-dimensional computation. We compared our results with those obtained by others using basically two-dimensional computation. Effect of two parameters, Reynolds number and liquid depth on the flow evolution is studied. We found that 2-D result is not accurate enough, and the vertical velocity distribution should be assumed of a fourth-order polynomial function for a better comparison.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.452-453
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• 2010

This paper proposes a novel diagnosis scheme using Extend Kalman Filter (EKF), especially, in subject to the open-phase faults of the inverter switches. The stator resistances of PMSM are estimated by the EKF in real time. The proposed diagnosis scheme is implemented without any extra devices. Moreover, since it uses a simple algorithm by analyzing only estimated stator resistances of each phase, the detection speed becomes fast. The feasibility of the proposed fault diagnosis scheme is proved by several simulation and experimental results.

• International Journal of Quality Innovation
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• v.2 no.2
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• pp.93-100
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• 2001

This paper illustrates a prototyping framework of the documentation-standards retrieval system via the data mining approach for enhancing software development quality. We first present an approach for designing a retrieval algorithm based on data mining, with the three basic technologies of machine learning, statistics and database management, applied to this system to speed up the searching time and increase the fitness. This approach derives from the observation that data mining can discover unsuspected relationships among elements in large databases. This observation suggests that data mining can be used to elicit new knowledge about the design of a subject system and that it can be applied to large legacy systems for efficiency. Finally, software development quality will be improved at the same time when the project managers retrieving for the documentation standards.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.4
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• pp.56-65
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• 1986

This paper theoretically analyzed the relations between the out-put braking torque and the wheel cylinder pressure in the leading-trailing drum brake for heavy duty truck as the characteristics of friction in break lining, comparing with the results derived from full-scale inertial brake dynamometer test in actual braking condition to develop reliable brake system in extensive using conditions. The main results obtained are as follows; 1) The characteristic curve representing the relations between BEF (Brake Effectiveness Factor) and Friction coefficient derived from theoretical analysis are consistent with the experimental results of dynamometer test. 2) According to the results of dynamometer test, the friction coefficient of brake lining is subject to initial brake speed and the actual using temperature in brake system.