• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.202-211
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• 2005

This paper introduces and illustrates the results of a new method fer offsetting triangular mesh by moving all vertices along the multiple normal vectors of a vertex. The multiple normal vectors of a vertex are set the same as the normal vectors of the faces surrounding the vertex, while the two vectors with the smallest difference are joined repeatedly until the difference is smaller than allowance. Offsetting with the multiple normal vectors of a vertex does not create a gap or overlap at the smooth edges, thereby making the mesh size uniform and the computation time short. In addition, this offsetting method is accurate at the sharp edges because the vertices are moved to the normal directions of faces and joined by the blend surface. The method is also useful for rapid prototyping and tool path generation if the triangular mesh is tessellated part of the solid models with curved surfaces and sharp edges. The suggested method and previous methods are implemented on a PC using C++ and illustrated using an OpenGL library.

• Korean Journal of Human Ecology
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• v.10 no.2
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• pp.37-42
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• 2007

The scale and the extent of a aging of population of a rural are more serious than those of a urban in China. However, the welfare policy and the service for the aged in the rural are inferior. China established the different systems of social welfare policy for the city and the rural and has administered it since the china was established. Owing to an open-door policy(opening of a reform) the gap between the two got more deeply distinguished. Accordingly. the striking difference is shown in a living environment and a quality of life of the cities and the rural. I made clear the difference of services for the aged in the rural and the urban examining daily lives, medical industry, recreation systems and so on and analyzing their sources. In addition, I proposed the ways to establish synthetic social welfare policy of the urban and the rural.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 1999.02a
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• pp.146-149
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• 1999

A 30kVA superconducting generator has been designed, developed and successfully tested recently. The design is based on 2-dimensional electromagnetic field analysis. The rotor has been wound with superconducting wire of Nb-Ti alloy. The stator has the air-gap type armature windings. Open-circuit test, short-circuit test and lamp load test have been conducted. The details of design program, design, machinebuilding, test results and conclusions are given in this paper.

• Journal of electromagnetic engineering and science
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• v.2 no.1
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• pp.11-15
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• 2002

In this paper, we have proposed the new configuration of wideband antenna using CPW fred lines. The proposed antenna has CPW feed lines and U-slot to achieve wade bandwidth with good impedance matching. The use of CPW feed line can decrease the number of substrates. It is compared with the conventional antenna find by a microstrip fled line. The parameters of CPW fred lines were studied by using the quasi-static approximation which is based on the conformal mapping method. The analysis of CPW discontinuities such as the tapered-step structure and the open ended gap were studied by using the quasi-static approximation which is based on the boundary element method. Also, the equivalent circuit model of multi-layer antenna were proposed using the cavity model. Experiment results of the proposed antenna 7how wide-bandwidth characteristics and good radiation patterns in passband.

• Journal of IKEEE
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• v.22 no.2
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• pp.480-483
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• 2018

Wireless power transfer (WPT) is the technology that forces the power to transmit electromagnetic field to an electrical load through an air gap without interconnecting wires. This technology is widely used for the applications from low power smartphone to high power electric railroad. In this paper, the model of wireless power transfer circuit for the low power system is designed for a resonant frequency of 13.45 MHz. Also, a feedback WPT circuit to improve the power transfer efficiency is proposed and shown better performance than the original open WPT circuit, and the methodology for power efficiency improvement is studied as the coupling coefficient increases above 0.01, at which the split frequency is made.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.2
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• pp.199-205
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• 2013

Stress and deformation on forklift happened at loading, unloading or moving freight are studied by structural and fatigue analysis in this study. As model 1 as closing type between forks has lower stress and stain than model 2 at opening type, model 1 has more durability than model 2. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'SAE bracket history' with the severest change of load at model 1 and 2, maximum life is shown with Cycle. Minimum damage with 854 at model 2 becomes much higher than model 1. As the gap between forks becomes open, the damage probability becomes higher. The structural result of this study can be effectively utilized with the safe and stable design of forklift by investigating prevention and durability against its damage.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.181-184
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• 2001

A coplanar waveguide(CPW) on a dielectric substrate consists of a center strip conductor with semi-infinite ground planes on either side. This type of waveguide offers several advantages over microstrip line. It facilitates easy shunt as well as series mounting of active and passive devices. It eliminates the need for wraparound and via holes, and it has a low radiation loss. These, as well as several other advantages, make CPW ideally suited for microwave integrated circuit applications. However, very little information is available in the literature on models for CPW discontinuities. This lack of sufficient discontinuity models for CPW has limited the application of CPW in microwave circuit design. We presented for the characteristics of coplanar waveguide open end capacitance and series gap capacitance. Measurements by utilizing the resonance method were made and the experimental data confirmed the validity of theories. The relationships between the CPW capacitances and the physical dimensions were studied.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.2
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• pp.232-242
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• 2015

Analytical study of surface recombination at the $Si/SiO_2$ interface is carried out in order to set the optimum surface conditions that result in minimum dark base current and maximum open circuit voltage in silicon solar cells. Recombination centers are assumed to form a continuum rather than to be at a single energy level in the energy gap. It is shown that the presence of a hump in the dark I-V characteristics of high efficiency PERL cells is due to the dark current transition from a high surface recombination regime at low voltage to a low surface recombination regime at high voltage. Successful fitting of reported dark I-V characteristics of a typical PERL cell is obtained with several possible combinations of surface parameters including equal electron and hole capture cross sections.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.158-161
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• 2006

In this paper, we deal with EMI Analysis on Microstrip with Defected Ground plane. Specially, we investigate reflection, transmission, crosstalk, radiated emission on Microstrip with Defected Ground plane structure. And investigates undesired effects on various defected ground plane such as ground with split, slot, short end and open end gap. To analyze reflection, transmission and crosstalk of microstrip with defected ground plane, we used concept of the microstrip to slot line transition model. Besides, investigate radiated emission using FDTD Commercial tools such as CST MW

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.114.2-114.2
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• 2014

The orientation of the constituent molecules in organic thin film devices can affect significantly their performance due to the highly anisotropic nature of ${\pi}$-conjugated molecules. We report here an angle dependent x-ray absorption study of the control of such molecular orientation using well-ordered interlayers for the case of a bilayer heterojunction of chloroaluminum phthalocyanine (ClAlPc) and C60. Furthermore, the orientation-dependent energy level alignment of the same bilayer heterojunction has been measured in detail using synchrotron radiation-excited photoelectron spectroscopy. Regardless of the orientation of the organic interlayer, we find that the subsequent ClAlPc tilt angle improves the ${\pi}-{\pi}$ interaction at the interface, thus leading to an improved short-circuit current in photovoltaic devices based on ClAlPc/C60. The use of the interlayers does not change the effective band gap at the ClAlPc/C60 heterointerface, resulting in no change in open-circuit voltage.