• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.118.5-118
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• 2002

To apply induction hardening method to a press die having 3-D free surface, the induction hardening tool moves on a press die above 1～2mm gap with constant velocity. Since the induction hardening process requires its own hardening path for each die, a direct teaching method which generates working path directly guided by operators is more suitable than an offline method using CAD/CAM data. The direct teaching apparatus in this work includes a teaching tool with a force/torque sensor and data processing computer to finally generate robot's Induction hardening program , in direct teaching operation, an operator teaches working path maintaining contact with surface of press die by holding...

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.144-145
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• 2003

A feasibility study on the alternating jet flow under the static electromagnetic field was carried out. When a fluid with electrical conductivity lies in the static electromagnetic field and moves electric current occurs in the fluid. Due to the electromagnetic field and the electric current, lorentz force generates in the fluid, which undergo the 'breaking' effect to the fluid. In order to simulate the complex fluid flow in the magnetic field, electromagnetic and fluid flow analysis need to be solved simultaneously. In the present study, a SOLA (SOLution Algorithm) scheme was used in order to calculate electromagnetic and fluid flow field. Jet flow without an electromagnetic field was compared with analytical solution in order to validate the flow analysis scheme. Effect of jet velocity on the flow pattern down the jet was investigated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.9
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• pp.2981-2990
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• 1996

Dual solutions for steady natural convection of air between two horizontal concentric cylinders are numerically investigated in the range of $D_i$/TEX>/L(=diameter of inner cylinder/gap width)$\leq$10. It is found that, when the Rayleigh number based on the gap width exceeds a certain critical value, a new flow pattern forming two counter-rotating eddies in the half of the annulus can be realized, which is different from the crescent-shaped flow commonly observed. In the new flow pattern, the fluid near the top of the hot inner cylinder moves downward. This solution is found for D$_{i}$/L.geq.0.3, but not for$D_i$/TEX>/L$\leq$0.2. As $D_i$/TEX>/L increase, the critical Rayleigh number is decreased, and tends to a finite limit.t.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.4
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• pp.561-569
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• 2000

The purpose of this study is to construct a testing equipment with which several characteristics of the domestically developed swashplate type axial piston motor can be tested and to develop a software with which the data from experiment can be stored and can be applied. The results of the study are as follows; 1) The leakage flow and the torque of the motor being stopped is propotional to supply pressure and their relation can be showed by linear equations. 2) The motor movement is not smooth below 50 rpm but it moves smoothly up 170 rpm. 3) When the motor starts or stops, the pressure rise ratio effects decisively to the max. torque.

• Journal of Korean Society for Quality Management
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• v.8 no.2
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• pp.29-37
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• 1980

The purpose of this study is to define the role of a T. Q. C. engineer in the plant engineering activities. A "plant engineering" moves to complete a new project through a series of stages such as: 1. Research & Development stage. 2. Economic evaluation & engineering design stage. 3. Erection & start up stage. 4. Final production & control stage. This suggests that the plant engineering project should be carried out with a wide variety of tasks, as well as a central control. For a successful completion of the project, a T. Q. C. engineer is required, in practice, either as a central activity creator or as a key advisor in each task.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.6
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• pp.85-93
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• 1997

This paper analyzes the steady-state and dynamic characteristics of the watkings-johnson converter. the major contributions of this paper includ identification of the following characteristics unique to the watkins-johnson converter: (1) The output voltage of the converter is nearly constant at the continous conduction mode (CCM), and at discontinousou conduction mode (DCM) it decreses linerly as the output curretn increases. (2) The control-to-output transfer function is a second-order one with a left-half-plane (LHP) zero determined by the combination of the output capacitor and equivalent series resistor of the converter. This LHP zero signinificantly improves the stability of the converter. (3) The control-to-output transfer function reduces to a first-order one, as the converter moves from CCM to DCM. (4) The parastic resistance of the inductor does not cause any significant influence on poles and zeros of the transfer function.

• Journal of Oriental Neuropsychiatry
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• v.11 no.2
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• pp.201-214
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• 2000

1. Essence and Spirit of association go well embodiment of mind goes well.2. Being component part by Three Valuable Properties of human body that is Essence, Vital force and Spirit, Cause that disease results is something wrong of Essence, Vital force and Spirit.3. Essence. Vital force and Spirit cycle that see in Doga is that circulate through intermediate of saliva.4. Morality curative means getting stability of mind as removing greed and it is that disease moves backward then naturally.5. Fantasy and uneasiness about the future is cause of disease of mind.

• Journal of Mechanical Science and Technology
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• v.18 no.3
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• pp.460-470
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• 2004

A computational analysis of engineering problems with moving domain or/and boundary according to either Lagrangian or Eulerian approach may encounter inherent numerical difficulties, the extreme mesh distortion in the former and the material boundary indistinctness in the latter. In order to overcome such defects in classical numerical approaches, the ALE(arbitrary Lagrangian Eulerian) method is widely being adopted in which the finite element mesh moves with arbitrary velocity. This paper is concerned with the ALE finite element formulation, aiming at the dynamic response analysis of baffled fuel-storage container in yawing motion, for which the coupled time integration scheme, the remeshing and smoothing algorithm and the mesh velocity determination are addressed. Numerical simulation illustrating theoretical works is also presented.

• Kyungpook Mathematical Journal
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• v.47 no.3
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• pp.329-334
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• 2007

By the works of Levine [2] and Rolfsen [5], [6], it is known that a local move called a crossing-change is strongly related to the Alexander invariant. In this note, we will consider to what degree the relationship is strong. Let K be a knot, and $K^{\times}$ the set of knots obtained from a knot K by a single crossing-change. Let MK be the Alexander invariant of a knot K, and MK the set of the Alexander invariants $\{MK\}_{K{\in}\mathcal{K}}$ for a set of knots $\mathcal{K}$. Our main result is the following: If both $K_1$ and $K_2$ are knots with unknotting number one, then $MK_1=MK_2$ implies $MK_1^{\times}=MK_2^{\times}$. On the other hand, there exists a pair of knots $K_1$ and $K_2$ such that $MK_1=MK_2$ and $MK_1^{\times}{\neq}MK_2^{\times}$. In other words, the Gordian complex is not homogeneous with respect to Alexander invariants.

• Journal of Satellite, Information and Communications
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• v.3 no.2
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• pp.26-31
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• 2008

As a multi-mission GEO satellite, Communication, Ocean, and Meteorological Satellite (COMS) is scheduled to be launched in the year 2009. COMS has three different payloads: Ka-band communication payload, Geostationary Ocean Color Imager (GOCI) and Meteorological Imager (MI). Among the three payloads, MI and GOCI have several conflict relationships; one of them is that if MI mirror moves vertically larger than 4 Line Of Sight (LOS) angle while GOCI is imaging, image quality of GOCI becomes degraded. In this paper, MI scheduling algorithm to prevent GOCI's image quality degradation will be presented.