• Design & Manufacturing
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• v.8 no.1
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• pp.40-44
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• 2014

As a rotating machine element, plastic gears are more and more widely used in such as industrial machine element, since plastic gear is lighter, higher wear-resistance, and higher vibration absorbing ability than metal gears. When operating plastic parts, tooth breakage and fatigue life shortened due to increasing number of applying load and tooth flank temperature rising, such that accuracy of plastic gears is divided from allowable range to cause vibration and noise. On this study, a internal plastic gears are developed which improved the filling balance molding process by a new injection mold structure. The new mold structure called HR3P(hot runner type 3plate mold). As the result from this studies, we obtained a very accurate roundness internal gears by using design of experiment.

• Korean Journal of Optics and Photonics
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• v.13 no.1
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• pp.27-31
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• 2002

We design a 1$\times$4 optical splitter made of photonic crystal waveguides and analyze the properties of the optical splitter using the finite-difference time-domain method with perfectly-matched-layer absorbing boundaries. The photonic crystal is constructed from cylindrical rods in air on a square lattice. Our simulation results show that there are different transmission properties for four bend geometries and different incident-wave frequencies. The sum of the power transmission of the splitted light is over 93 percent at a certain geometry and frequency, and the incident power splits in the four arms with almost the same ratio.

• Textile Coloration and Finishing
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• v.4 no.1
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• pp.21-25
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• 1992

The charge-transfer(CT) complexes derived from various donors and acceptors were evaluated as coloring matter. Dyes absorbing light in the region from the visible to the near-infrared wavelengths were synthesized. In order to determine the molar ratio of the donor to the acceptor in the CT complex in the solution, the continuous variational method was applied to each system. A 1:1 correspondence between the donor and the acceptor molecules in the CT complex in the solution is established. Color development properties in paper were examined. The longer the exposure time at constant temperature, the deeper the strength of color in paper. The strength of color at high temperature was decreased, because sublimed CT dyes in paper were migrated out side of paper.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.129-136
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• 2000

In the frontal collision the spot welded hat-shaped section side member is the fundamental structure for automobiles and has a great amount of absorbing capacity. For this reason LS-DYNA3D has been used for analyzing impact collapse characteristics on hat shaped section member with respect to the valuables; thickness, width ratio and spot weld potch on impact load(7.19m/sec, 1034J). By comparing the results from simulation and the experimental results, the utilization of simulation has been certified.

• Journal of Power System Engineering
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• v.12 no.6
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• pp.78-82
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• 2008

Plastic gears are more and more widely used in many industrial machine elements. Plastic gear has higher properties such as light weight, wear resistance, and vibration absorbing ability than metallic gears. But, in case of using an inaccurate plastic gear, its tooth breakage happen and fatigue life is shortened due to increase of applying load and temperature rising on the tooth flank. Inaccuracy of plastic gears such as pitch circle roundness and tooth profile generates vibration and noise. In this study, an internal plastic gears which is molded by a new injection mold structure are developed. The new mold structure is called the HR3P(hot runner type 3plate mold) that has an improved runner system in order to have good filling balance. As a result from this study, an internal gear with very accurate roundness was developed by using design of experiment.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.5
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• pp.218-222
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• 2012

FeNi alloy nanofibers have been prepared by an electrospinning process followed by air-calcination and H2 reduction to develop electromagnetic (EM) wave absorbers in the giga-hertz (GHz) frequency range. The thermal behavior and phase and morphology evolution in the synthetic processes were systematically investigated. Through the heat treatments of calcination and H2 reduction, as-spun PVP/FeNi precursor nanofiber has been stepwise transformed into nickel iron oxide and FeNi phases but the fibrous shape was maintained perfectly. The FeNi alloy nanofiber had the high aspect ratio and the average diameter of approximately 190 nm and primarily composed of FeNi nanocrystals with an average diameter of ~60 nm. The FeNi alloy nanofibers could be used for excellent EM wave absorbing materials in the GHz frequency range because the power loss of the FeNi nanofibers increased up to 20 GHz without a degradation and exhibited the superior EM wave absorption properties compared to commercial FeNi nanoparticles.

• Journal of Advanced Marine Engineering and Technology
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• v.16 no.3
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• pp.24-29
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• 1992

This paper describes a technique to suppress vibrations of structure under excitation by attaching the hollow rotor partially filled with liquid. The influence of the amount of liquid, number of fins and their widths on absorbing vibration is investigated. The results of experiments are summarized as follows: 1. The effect on suppressing vibration at filling ratio, H over bar = 0.54 is greatest. 2. The viscosity of liquid hardly influence on suppressing vibration. 3. The rotor fitted with two pins having width of pin =(D-$D_f$)/4 is effective generally. 4. The vibration damping effect of the axial fins is greater than that of radial fins.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.109-110
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• 2016

This study is a absorbing Radon gas to occur indoor or outdoor. As a absorbent Radon gas, making cementless abso rbent matrix that accomplish experiment. In other to accomplish this experiment, Confirming Radon gas release ratio and accurating absorption, reduction of a half-life that 3,8 days from Radon gas source, we need to decide Radon absorbent experiment method. So, we accomplish to find Radon measurement method considering properties and a half-life that 3,8 days from Radon gas source. As the experimental factors, After stabilizing of Radon gas source and so on, we accomplish the experiment that is there or not and seal of Radon source.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.460-463
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• 2003

In this paper, we present the properties of water absorption of elastic epoxy for high voltage. The ratio of water absorption shows linearly increase according to ${\sqrt}t$ till 66 hours. And rigid epoxy is 0.053 [%], elastic epoxy at addictives 35 [phr] is 0.309 and it at addictives 70 [phr] is 0.44 [%]. The reason where absorption of elastic epoxy is high is because of micro void. It can be confirmed by SEM analysis. Dieletric constant increased linearly by addictives' concentration and tans is also increased by addictives' concentration.

• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.129-133
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• 2008

As a rotating machine element, plastic gears are more and more widely used in such as industrial machine element, since plastic gear is lighter, higher wear-resistance, and higher vibration absorbing ability than metal gears. When operating plastic parts, tooth breakage and fatigue life shortened due to increasing number of applying load and tooth flank temperature rising, such that accuracy of plastic gears is divided from allowable range to cause vibration and noise. On this study, a internal plastic gears are developed which improved the filling balance molding process by a new injection mold structure. The new mold structure called HR3P(hot runner type 3plate mold). As the result from this studies, we obtained a very accurate roundness internal gears by using design of experiment.