• Journal of Institute of Control, Robotics and Systems
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• v.22 no.4
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• pp.281-287
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• 2016

In this paper, we propose a novel compact surveillance throwing robot which has an omnidirectional shock absorption mechanism and an active control part of wheel treads to stabilize the dynamic posture of a miniature sphere type throwing robot. This throwing robot, which weighs 1.14kg and is 110mm in height, is designed in a spherical shape to be easily grabbed for throwing. Also, the omnidirectional shock absorbing aspect is designed using several leaf springs connected with inner and outer wheels. The wheel treads control part consists of a link mechanism. Through the field experiments, this robot is validated to withstand higher than 17Ns of omnidirectional impulse and increase the stabilized max speed three times from 11 rad/s to 33rad/s by increasing wheel treads.

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.220-225
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• 1985

An attempt was made to determine some trace metals in highly concentrated samples using micro sampling technique in flame atomic absorption spectrophotometry. Major instrumental parameters and optimun analytical conditions investigated were the measuring time of instrument (the speed of electronics), sample volume, burner height, aspiration rate, and fuel to oxidant ratio. Advantages of the present technique are not only rapid, simple, and sensitive with good precision but also capability of analyzing small volume of sample and ability to handle highly concentrated samples without serious burner clog-up problem compared to conventional flame atomic absorption.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.97-100
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• 1998

We studied on the ultra thin L-${\alpha}$-DLPC by LB method. The $\pi$-A isotherm of the L-${\alpha}$-DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. The molecular arrangement of deposited films were evaluated by measuring the absorption with the UVspectrometer. And we made structures of metal(Au)/L-${\alpha}$-DLPC/Metal(Au) and examined electron through L-${\alpha}$-DLPC LB films by means of current-voltage(I-V) measurement.

• Tribology and Lubricants
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• v.19 no.5
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• pp.259-267
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• 2003

A brake device for the high-speed impacting object is designed using an axial crushing of thin-walled metal cylinder. Thickness of the cylinder is increased smoothly from the impacting end to the fixed end, resulting in the truncated cone shape. Truncated cone shape minimizes the imperfection-sensitivity of the structure and ensures that plastic hinges are formed sequentially from impacting end. This prevents the undesirable sudden rise in the first peak-crushing load. Several specimens with different conic angles, mean thickness of the wall, and materials were designed and quasi-static compression tests were performed on them. Results indicate that adoption of appropriate conic angle prevents simultaneous wrinkles generation and sudden rise of crushing load and that appropriate conic angle differs in each case, depending on the geometry and material property of the cylinder. Finite element analysis was performed for static compression of the cylinder and its accuracy was checked for the future application.

• Journal of the Optical Society of Korea
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• v.15 no.3
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• pp.227-231
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• 2011

An external optical modulation using absorption s in a Fabry-Perot laser diode (FP-LD), has been proposed and experimentally demonstrated for multicasting in a WDM-PON. The center wavelengths of absorption s in an FP-LD move to short-wavelength rapidly by only a small current (~1 mA) injection. If the current injection is stopped, the s move back to the original position. Such a movement of the s can make the FP-LD act as an external optical modulator, which is found to modulate at a maximum modulation speed of 800 Mbps or more. For a multicasting transmitter in a WDM-PON, the proposed modulator can be cost-effectively applied to a multi-wavelength laser source with the same periodicity of the longitudinal mode. Instead of the multi-wavelength laser source, tunable-LDs are used for experiments. The 32 channel multicasting system with the proposed modulator has been demonstrated, showing power penalties of 1.53~4.15 dB at a bit error rate of $10^{-9}$ with extinction ratios better than 14.5 dB at 622 Mbps.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.849-854
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• 2001

Cabin noise reduction in maglev trains developed by KIMM is studied. Based on the measurements of cabin noise and acceleration levels during running and zero speed conditions, dominant noise sources are identified. After spectra characteristics of noise sources is investigated, efficient noise reducing methods are studied such as STL increasement of floor panels, sealing, and absorption treatment. It is found that the most important noise sources are VVVF inverter and SLIM in running condition. Since the noise sources are under the cabin floor, complete sealing and high STL of the floor panel are shown to be the most crucial factors in noise reduction. After polyurethan form (50t) is added for more sound absorption and sealing treatment, the cabin noise is reduced by 3-4 ㏈.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.10a
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• pp.66-75
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• 1997

This study was undertaken to investigate tribology characteristics of the alumina ceramics($Al_2O_3$) of the various purity for the variation of ambient condition such as air and vacuum. The wear test was carried out under different experimental condition using the wear test device, which was designed for this study, and in which the annular surface of wear testing specimens as well as mate specimen made of STB2 steel, were subjected to sliding speed, applied load and the sliding distance. The results obtained were as follows. As the ambient pressure decreases, the friction coefficient increases because the protective layer made of absorption due to decrease of the amount of ambient gas can not be formed. As the friction coefficient paticularly for 85% alumina lower than 95% and 99.7% in the alumina purity increases by an influence of heat accumulation caused by small elastic modulus and thermal conductivity. The friction surface of ceramics can be protected in the air by the influence of the oxides transfered from STB2. However, in the vacuum, the protective layer made of the absorption substance can not be formed due to the decrease of ambient gas.

• Journal of the Korean Ceramic Society
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• v.42 no.10 s.281
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• pp.678-684
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• 2005

Sick house syndrome comes from VOCs that is harmful to health. To reduce VOCs, the cause of sick house syndrome, several materials have been developed and use. One of this materials, VOCs absorption paint was developed. VOCs absorption paint contains ceramic binder and zeolite powder. In the present study, eco-ceramics paint has been successfully fabricated by high-speed mixer using ceramic binder and filler powders. The eco-ceramics paint thus obtained have a deodorization rate with about 95.7$ \%$ and the bacteria decreasing rate is about 99.6$\%$. Moreover, the eco-ceramics paint showed excellent VOCs interception properties due to effect of ceramics layer and zeolite which exist in surface of paint.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.377-384
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• 1998

The crushable front part of the conventional TGV is composed of 3 energy absorption zones; retractable coupler, protective headstock and honeycomb structure. This frontal part must absorb about 80% of the energy that should be done in a cra shworthy design. The conventional TGV can absorb 2MJ impact energy by the frontal end, but 5MJ is the design target for energy absorption in the next generation TGV. To accomplish this design goal, a new concept of design is necessary for energy absorbing components. In this paper, the design concept of the tube expansion energy absorber will be proposed and analyzed. The crash analysis of the energy absorber are performed by comparing the value of the theoretical equation wi th the simulation calculated from the commercial nonlinear FE-Code ‘PAM-CRASH’ S/W.

• The Journal of Information Technology
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• v.8 no.3
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• pp.51-56
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• 2005

In this paper, we describe a study on the relationship between spectral sensitization and photographic characteristics of color paper. The photographic emulsion used in this study is a green-sensitizing emulsion. U.V maximum absorption peak value of 9-phenyl-5,5'-diphenyl-3,3'-bis(3-sulfopropyl)benzoxazolo carbocyanine triethyl ammonium salt was observed 507nm, and wedge spectrograms maximum peak value of color paper added dye to photographic emulsion was shown 553nm. As compared with the absorption peak of the dye in methanol solution, the sensitizing peaks of 9-phenyl-5,5'-diphenyl-3,3'-bis(3-sulfopropyl)benzoxazolo carbocyanine triethyl ammonium salt have red shifts of 46nm. The photographic characteristics of green-sensitizing emulsion were obtained contrast(2.6), speed(48-57), fog(0.08). Therefore, benzoxazolo carbocyanine dye is of industrial importance as green-sensitizing dye in the spectral sensitization of photographic emulsion.