• 한국농공학회지
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• 제10권1호
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• pp.1409-1412
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• 1968

Some simple devices to demonstrate important hydraulic principles are required in fluid mechanics or hydraulics classes. Those devices should be easy to make and operate with inexpensive cost. The writer has studied some simple demonstration apparatus of hydraulic principles which were made of cheap materials. An adjustable nozzle is one of them. It can be connected to an axial flow fan so as to use air flow. By operating this apparatus, pressure changes in gradually enlarged or contracted conduits could be observed.

• Journal of Mechanical Science and Technology
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• 제19권5호
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• pp.1107-1115
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• 2005

In this study, a position and force simultaneous trajectory tracking control algorithm is proposed for a driving apparatus that consists of two pneumatic cylinders connected in series. The controller applied to the driving apparatus is composed of a non-interaction controller to compensate for interaction between cylinders and a disturbance observer aimed to reduce the effect of model discrepancy that cannot be compensated by the non-interaction controller. The effectiveness of the proposed control algorithm is proved by experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.825-827
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• 2003

There are many problems when air core reactor is used. Especially, measure instruments are influenced from magnetic field. This paper shows the research results for the magnetic field shielding on air core reactor.

• Bulletin of the Korean Chemical Society
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• 제22권8호
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• pp.883-888
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• 2001

We describe an ion-surface scattering apparatus newly developed to investigate the reactive scattering process of low-energy alkali-metal ions at surfaces. The apparatus consists of an alkali-metal ion gun that is rotatable by 360°, a quadrupole mass spectrometer (QMS) with an ion energy analyzer, a sample manipulator with a heating-and-cooling stage, and an ultrahigh vacuum (UHV) chamber that houses these components. Preliminary experimental results obtained from the apparatus are presented on angular and energy distributions of the ions scattered from clean Pt(111) and water-adsorbed Pt surfaces.

• 소성∙가공
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• 제19권1호
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• pp.38-43
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• 2010

Electromagnetic forming (EMF) method is one of high-velocity forming processes, which uses electromagnetic Lorentz force. Advantages of this forming technique are summarized as improvement of formability, reduction in wrinkling, non-contact forming and applications of various forming process. In this study, the EMF apparatus is developed. It is designed to be stored in 10 capacitors connected in parallel, each with a capacitance of $50{\mu}F$ and maximum working voltage of 5kV. The system has capacitance of $500{\mu}F$ and maximum stored energy of 6.25kJ. And EMF experiments are carried out to verify the feasibility of the EMF apparatus, which has enough forming force from the results of EMF experiment. In addition, peak current carrying a forming coil is predicted from theoretical background, and verified the predicted value compared with experimental value using the current measurement equipment. Consequently, EMF apparatus developed in this study can be applied to various EMF researches for commercialization.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.37-42
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• 1990

In order to obtain optimal design criteria and operating parameters, a Single-sided Linear Induction Motor (SLIM) is analysed by using a 2-D finite element method with magnetic and current vector potential. In the analysing procedures, the governing equation is derived from Maxwell's equation combined with the magnetic vector potential. As a forcing term, 3-phase voltage source is employed using the Kirchhoff's voltage law in order to look into effects of the unbalanced 3-phase currents and air gap flux density. Also, 2ndary eddy current distribution, longitudinal end and transverse edge effects are in turns visualized by flux lines in 3 different analysing planes as functions of frequency and input power.

• 대한기계학회논문집B
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• 제27권2호
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• pp.259-264
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• 2003

One Clausius inequality based on an apparatus with a single thermal reservoir is reviewed. Some intricate issues regarding the apparatus are brought up and therefore a preferred way to interpret the Kelvin-Planck statement is suggested. Then it is shown that another Clausius inequality can be established from a direct application of the proposition regarding the efficiency of a Carnot cycle. The establishment is based on an apparatus with two reservoirs, and the resultant inequality involves the temperature of external reservoir. Finally, a different apparatus which also has two thermal reservoirs is utilized to compare the cyclic integral of the former inequality with the one of the latter resulting in the proof of the former inequality which involves the temperature at the system boundary. The applications and limitations of these two Clausius inequalities are discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.106-109
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• 1991

A magnet is designed and analysed using a finite element method program (FLUX2D), which will be employed to the 2-module MAGLEV test vehicle for developing of DAE JEON EXPO '93 Magnetic Levitation System. Levitation force. guidance force and thermal characteristics are examined according to the variation of parameters of the magnet ie. pole width, window area, rail configuration, input current and so on. An optimal geometry of the magnet are provided.

• 한국해양공학회지
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• 제17권1호
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• pp.72-79
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• 2003

This paper deals with the development of an interface program for automatic plate forming, which can exchange information between the heating line information generation program and the automatic heating apparatus. In this paper, the performance of the developed interface program has been verified from the view point of numerical position control. By applying the interface program to the operation of the automatic heating apparatus, an experiment of line heating has been conducted for several steel plate models. Based on the experimental results, a simplified relation to estimate angular distortion has keen derived as a natural characteristic of the present automatic heating apparatus. As a result of the present study, the prototype of the automatic plate forming system has been constructed, and its application to the real surface models found in the ship will be presented in the near future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.59-61
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• 2003

The natural element method is a kind of meshless Galerkin method. The shape function is derived from the natural neighbor coordinates interpolation scheme. Natural neighbor shape functions are $C^0$ everywhere, except the nodes where they are $C^0$. The numerical integration is carried out using the Delaunay triangles as the background cells. The method is applied to the test problems and simulation results show that the natural element method can give accurate solutions for the electromagnetic field problems.