• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.663-665
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• 2002

Moving flat core type LOA consists of iron flat core as a mover and electric magnet as a stator and operated by electromagnetic force between mover and stator. First, this paper describes the voltage equation of coil and the mechanical equation of motion. Secondly, the dynamic simulation algorithm is proposed, and system control constant-inductance, resistance-were carried by exciting coil. Finally, we turned out the driving system and the dynamic characteristics of current, voltage and displacement is confirmed by experiment.

• Journal of ILASS-Korea
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• v.1 no.2
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• pp.66-73
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• 1996

The present study investigates experimentally the characteristics of liquid jet, which is, the spray flow in the normal direction of the air stream under the flow conditions of air velocity $110\sim125m/s$. The present study adopts with the flow visualization technique using a short duration light bulb and the image processing analyse with CCD camera. Two types of injector were used: one is a flat plate type, and the other is backward facing step type, which height are 5, 8, 10mm. Dispersion of liquid jet can be represented by gray level of CCD camera. In the upstream of liquid jet, the backward facing step shows better liquid jet penetration. However, in the downstream. mean droplet size for backward facing step injector is smaller than that for flat plate injector

• East Asian mathematical journal
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• v.19 no.2
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• pp.261-271
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• 2003

We deal with two metrics of Randers type, which are characterized by the solution of certain differential equations respectively. Furthermore, we will give the condition for a Finsler space with such a metric to be a locally Minkowski space or a conformally flat space, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1501-1502
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• 2011

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.289-294
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• 2002

Cellulose production by Acetobacter pasteurianus was investigated in static culture using four bioreactors with silicone rubber membrane submerged in the medium. The shape of the membrane was flat sheet, flat sack, tube and cylindrical balloon. Production rate of cellulose as well as its yield on consumed glucose by the bacteria grown on the flat type membranes was approximately ten-fold greater than those on the non-flat ones in spite of the same membrane thickness. The membrane reactor using flat sacks of silicone rubber membrane as support of bacterial pellicle can supply greater ratio of surface to volume than a conventional liquid surface culture and is promising for industrial production of bacterial cellulose in large scale.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.692-697
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• 2000

Recently, Flat flame burners are hilighted in high-load burners. Our study contains flow field analysis of a flat flame burner. In this paper, We analyzed the direction and magnitude of the velocity in a round tile type burner with swirl angles, $10^{\circ},\;30^{\circ},\;50^{\circ}$. In the case of swirl angle $10^{\circ}$, because axial momentum is larger than radial momentum, Recirculation region was weakly developed. In the case of swirl angle $50^{\circ}$, Flow in front of the tile is distributed for radial direction. And Recirculation region is large. So, We expect that the radiation can be transmitted from tiles and the recirculation region may cause $NO_x$ reduction.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.30-32
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• 1999

Electron beam trajectory simulation results on the high voltage FED with cone-type field emitters predict that the cross-talk phenomena would be seen due to the divergence of the electron beam. In this study, computer simulations with design of experiment technique and the SNU-FEAT program were carried out for five input parameters of the aperture focusing structure. The results tell that the focusing voltage is a dominant factor. And, the beam divergence index could be reduced to 10.7$\mu\textrm{m}$ with the aperture focusing structure, however, the operating voltage of the field emitter is predicted to increase by 40% maximum.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.572-573
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• 2005

Discharge of the flat lamp lighting source research are requested very much. For improving brightness. life time. efficiency of flat lamp and plasma diagnosis of the flat lamp lighting source to understand property of lighting source is very important. When a distance of discharge electrode is 5.5mm and width is 16.5mm. we measured electron temperature and electron density measured with single Langmuir probe in flat lamp. We tested the discharge from 100 Torr to 300 Torr pressure. The pulse type was rectangular with frequency 20kHz and duty ratio was 20%. In result. electron temperature decreases and electron density increased as increase the gas pressure and electron temperature decreases and electron density increase as increase the voltage.

• The Research Journal of the Costume Culture
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• v.23 no.5
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• pp.894-905
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• 2015

The present study analyzed data from the 3D measurement of the feet of men aged over 20 years residing in the capital region as part of the 6th Anthropometry of Size Korea. To analyze the characteristics of the foot shapes of young men aged 20~39 years and middle-aged/elderly men aged 40~69 years by age and by type, a cluster analysis was conducted using the factors derived through the factor analysis as independent variables. The results of the study that analyzed the characteristics of foot shapes by type according to differences in age were as follows. First, through the analysis of the characteristics of the foot shapes of young men by type, five factors were extracted, and the foot shapes were classified into three types: Type 1 (short and flat), Type 2 (thick), and Type 3 (long and wide). Second, through the analysis of the characteristics of the foot shapes of middle-aged/elderly men by type, six factors were extracted, and the foot shapes were classified into four types: Type 1 (short and regular), Type 2 (flat), Type 3 (thick), and Type 4 (long and regular). The results of the present study are expected to serve as basic data for the design of shoes by age and foot type.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.2
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• pp.52-60
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• 2009

The purpose of this research is to develop high efficiency plastic plate heat exchangers which can be substituted for conventional aluminum plate heat exchangers. Four simulation models of plastic plate heat exchangers are designed and simulated: that is, flat plate type, turbulent promoter type, corrugate type and dimple type heat exchanger. The flat plate type is designed as the reference model in order to evaluate how much thermal performance increases. The turbulent promoter type is fabricated with cylindrical-type vortex generators and rib-type turbulent promoters. The corrugate type is obtained from the conventional stainless steel compact heat exchangers, which are called the herringbone-type compact heat exchangers. The dimple type has a number of dimples on its surface. In this study, the flow and heat transfer characteristics of the plastic plate heat exchanger are investigated using numerical simulation and compared with experimental results. Numerical simulation is carried out using the FLUENT code. The flows are assumed as a three-dimensional, incompressible and turbulent model. The computational analysis and experimental results both show that the friction coefficient and Nu number is highest in the corrugate type. The tendency of numerical simulation results is in good agreement with that of the experimental results.