• 한국정밀공학회지
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• 제15권12호
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• pp.212-219
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• 1998

During machining of dies and molds with sculptured surfaces. the cutter contact area changes continuously and results in cutting force variation. In order to implement cutting force prediction model into a CAM system, an effective and fast method is necessary. In this paper. a new method is proposed to predict mean cutting force. The cutter contact area in the spherical part of the cutter is obtained using Z-map, and expressed by the grids on the cutter plane orthogonal to the cutter axis. New empirical cutting parameters were defined to describe the cutting force in the spherical part of cutter. Before the mean cutting force calculation, the cutting force density in each grid is calculated and saved to force map on the cutter plane. The mean cutting force in an arbitrary cutter contact area can be easily calculated by summing up the cutting force density of the engaged grid of the force map. The proposed method was verifed through the slotting and slanted surface machining with various inclination angles. It was shown that the mean force can be calculated fast and effectively through the proposed method for any geometry including sculptured surfaces with cusp marks and holes.

• Journal of Magnetics
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• 제22권2호
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• pp.203-213
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• 2017

Magnetically suspended control & sensitive gyroscope (MSCSG) is a novel type of gyroscope with the integration of attitude control and attitude angular measurement. To improve the precision and reduce the power consumption of Lorentz Force-type Magnetic Bearing (LFMB), the air gap flux density distribution of LFMB has been studied. The uniformity of air gap flux density is defined to qualify the uniform degree of the air gap flux density distribution. Considering the consumption, the average value of flux density is defined as well. Some optimal designs and analyses of LFMB are carried out by finite element simulation. The strength of the permanent magnet is taken into consideration during the machining process. To verify the design and simulation, a high-precision instrument is employed to measure the 3-dimensional magnetic flux density of LFMB. After measurement and calculation, the uniform degree of magnetic flux density distribution reaches 0.978 and the average value of the flux density is 0.482T. Experimental results show that the optimal design is effective and some useful advice can be obtained for further research.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.201-203
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• 1997

As electromagnetic systems have the complexity and high performance, they should be designed to take into account the vibration, noise and strain of mechanical aspect as well as electrical problems. Until now, mechanical approaches have been tried to analyze the subject, but it is difficult to figure out the matter in mechanical consideration. Because they are mainly related to electromagnetic phenomena. This paper deals with the theories and numerical formulations of magnetic force density. Several methods are applied to an actuator and DC machine model to calculate magnetic force density. These results are compared with the total force obtained by maxwell stress tensor and virtual work principle.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1998년도 추계연구발표회 논문개요집
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• pp.122-123
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• 1998

• Transactions on Electrical and Electronic Materials
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• 제6권4호
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• pp.149-153
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• 2005

In this paper, we investigated the island density-dependent stress distribution of indium-tin-oxide (ITO) film on polycarbonate substrate by external bending force. We used e-beam and RF­sputter for SiON, ITO sputtering. It was found that there are influence of island density on the substrate and decreasing crack density as goes to the minimum density. From the result that crack density was increasing at maximum island density, it is evident that more stress is imposed on same island position as island density.

• 대한기계학회논문집A
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• 제30권9호
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• pp.1025-1033
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• 2006

This paper describes the levitation mechanism using magnetic wheel for a maglev planar transportation system. Rotation of the magnetic wheel where the permanent magnet array is embedded produces the time varying traveling magnetic flux density and the generated magnetic flux density creates the induced levitation force and drag force with the conductor. Because the net drag force is zero, magnetic wheel can only generate the levitation force. Thus, it always guarantees the stability in levitation direction and it does not disturb other directional motion. In this paper, levitation principle of the magnetic wheel is analyzed using distributed field approach and dynamic characteristics of the levitation in the magnetic wheel system are estimated. The feasibility of the proposed levitation mechanism is verified through the several experimental works.

• 한국식품영양과학회지
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• 제30권2호
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• pp.292-298
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• 2001

This study was conducted to investigate physicochemical properties of extrudates combining 4 levels of squid (0, 3, 5 and 7%) with 3 levels of defatted soy flour (0, 5, and 10%). Blends were adjusted to moisture content of 27% and then extruded in a single-screw laboratory extruder at 170rpm screw speed and 16$0^{\circ}C$ barrel temperature. The extruded materials were dried at 6$0^{\circ}C$ for 8hr to a moisture content of 3~4% and refrigerated at 4$^{\circ}C$ for 12 hour before examination for textural properties, expansion ratio, bulk density, shear force and Hunter color. Expansion ratio of extrudates decreased as squid content increased whereas bulk density and shear force increased. Expansion ratio of extrudates was not significantly different by defatted soyflour level. Bulk density of products decreased as defatted soyflour content increased but shear force of products increased as defatted soyflour content increased. In scores of sensory hedonic evaluation of snacks, appearance, flavor, texture and overall acceptability values had lowered as squid level increased. Therefore, according to materials contents on extrudates increased, nutritional contents of this products increased and also shear force and bulk density in physical properties increased whereas expansion ratio decreased.

• 드라이브 ㆍ 컨트롤
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• 제9권4호
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• pp.1-7
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• 2012

The voice coil linear force motor is a kind of a direct drive motion device that uses a permanent magnetic field and coil winding to produce force. In order to design a voice coil linear force motor, an exact calculations of the required force, the flux density in air gap and the flux pathway are needed. A conventional method can be used usually to calculate the flux density in air gap, but with this method it is needed to find a magnetic circuit revision constant. In this paper a voice coil linear force motor is designed by conventional design method and analyzed by 3D simulation program "Flux". For the prototype linear force motor, the results of the calculated by conventional design method and the analyzed by 3D simulation program are compared with the test result. Finally it is showed that the magnetic circuit revision constant which is found by comparing of the analyzed and the measured data can be used for the design of the voice coil type linear force motor to minimize the trial and error.

• Design & Manufacturing
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• 제6권2호
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• pp.48-53
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• 2012

In previous study, it showed that the MAP was greatly effective polishing process for magnesium plate. But it had lower efficiency than magnetic materials such as SM45C. It was very difficult to cut non-magnetic materials using the MAP process because the process was fundamentally possible by help of a magnetic force. This study aimed to verify analytically formation of the magnetic field in a case of the non-magnetic materials especially focused on magnesium plate. So, In this study, the magnetic density flux was predicted using simulation program. As a result, the magnetic density flux was lower at the center of pole on inductor than outside. It had same result on the experimental verification. And magnetic force was lower according to increase of working gap. So, to improve the magnetic force, permanent magnet was installed under the workpiece. In that case, the magnetic density flux not only at center but also at outside of pole was increased. Therefore, the efficiency of magnetic abrasive polishing was also increased. A design of experimental method was adopted for assessment of parameters' effect on the MAP results of magnesium plate for improving the magnetic force.

• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.45-50
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• 2008

In previous study, it showed that the MAP was greatly effective polishing process for magnesium plate. But it had lower efficiency than magnetic materials such as SM45C. It was very difficult to cut non-magnetic materials using the MAP process because the process was fundamentally possible by help of a magnetic force. This study aimed to verify analytically formation of the magnetic field in a case of the non-magnetic materials especially focused on magnesium plate. So, In this study, the magnetic density flux was predicted using simulation program. As a result, the magnetic density flux was lower at the center of pole on inductor than outside. It had same result on the experimental verification. And magnetic force was lower according to increase of working gap. So, to improve the magnetic force, permanent magnet was installed under the workpiece. In that case, the magnetic density flux not only at center but also at outside of pole was increased. Therefore, the efficiency of magnetic abrasive polishing was also increased. A design of experimental method was adopted for assessment of parameters' effect on the MAP results of magnesium plate for improving the magnetic force.