• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.99-106
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• 2006

High velocity oxygen-fuel thermal spray coating of the WC-Co cermet material is a well-established process for modifying the surface properties of the structural components exposed to the corrosive and wear attacks, and also these coating are well-known method to improve the fatigue strength of material. In this study, HVOF coated SM490B are prepared to evaluation of the effect of coating on tension and fatigue crack growth behavior. The pre-crack of the fatigue crack growth test specimens machined at deposited material area, heat affected zone and boundary, respectively. Through these test, the following results are obtained: 1) Tensile strength was about 498 MPa, and fracture occurred on base metal area. 2) The fatigue crack of coated specimens propagated more rapidly than non-coated specimen in all specimens. 3) In the same coating thickness specimens, the specimens with pre-crack at boundary more rapidly propagated than the specimens with pre-crack at HAZ and deposited material area. These results can be used as basic data in a structural integrity evaluation of rolled SM490B weldments considering HVOF coating.

• Journal of Ocean Engineering and Technology
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• v.16 no.1
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• pp.16-22
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• 2002

The diffusion characteristics of an ocean dumping material in the south-eastern East/Japan Sea related to regulate the physical characteristics with the observation and the hydraulic experiment are investigated. The main results are as follows; (1) Spying CTD observation result of the area of Jung in the East/Japan Sea, the ocean dumping area had influenced the Tsushima Warm Current of high temperature and salinity. Horizontal turbulent diffusivity is 1.913$\times$10$^{7}$ by drogue tracking. (2) From the experiment of settling, the initial settling velocity of each material is 1.0~2.7 cm/sec according to the specific gravity and initial concentration. In the pycnocline, particles didn't settle under the pycnocline any more and accumulated. It is signified that calculation of the sedimentation rate of the ocean dumping material including of vertical diffusion must be regard the pynocline in the ocean area have well-developed pycnocline. (3) Vertical turbulent diffusivity were 2.219$\times$10$^{-8}$ ~8.874$\times$10$^{-4}$ cm$^2$/sec from the experiment of settling. And, the pycnocline influenced the vertical turbulent diffusivity.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.2
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• pp.17-22
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• 2015

In this paper, we study the calculation for the fracture area of the composite material specimens using digital image processing techniques. This study was able to calculate the area of the fracture region through the main operation step 7 on the basis of improved image. To extract the area in the original image, we have to use opening operation, close operation, the Hit-or-Miss operation and Bottom hat filter, Top hat filter, etc. In particular, to extract the area of the composite specimen discussed in this study, we have to use the combination of the operations and filters because it is non-isotropic material, or should develop a new algorithm based on it.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.126-131
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• 2003

Kochang (Chollabuk-Do) located in the west-southern area of the Korea and passed by the West Coast Highway has yellow collar soil(Hwang-To) pertaining primarily clay. Hwang-To serve as a great soil for growing watermelon and yam but are not strong enough to be used as subgrade material for constructing roads. Subgrade material of the study site was not qualified for standard of material quality. Properties of subgrade layers showed that strength of subgrade material is not strong enough to sustain the subgrade strength in constructing roads since No. 200 passing ration is 25 - 82 ％ and ground water level is nearly equal to subgrade level. The objective of this study is to present the methods obtaining proper subgrade strength of cutting area to construct secure and solid highways in the fragile area.

• Journal of Navigation and Port Research
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• v.27 no.4
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• pp.485-489
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• 2003

The region of Kochang(Chollabuk-Do) located in the west-southern area of the Korea and passed by the West Coast Expressway has the yellow collar soil(Hwang-To) primarily containing clay. Hwang-To serves as a soil appropriate for growing the watermelon and yam, but as a subgrade material not strong for constructing the roads. Particularly, the subgrade material of this study site was not qualified for the standard of the subgrade material quality. The properties of the subgrade layer showed that the strength of the subgrade material was not strong enough to sustain the subgrade strength in constructing the roads since the passing ratio of the No. 200 sieve was about 25％ to 82％ and the ground water level was early equal to subgrade one. Thus, the objective of this study was to present the methods obtaining the proper subgrade strength of cutting area to construct the secure and solid expressways in the fragile area.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.601-604
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• 1999

Electroluminescence(EL) devices based on organic thin films have attracted lots of interests in large-area light-emitting display. Recently, many EL researcher have interested a new emissive organic material. In this study, light-emitting organic electroluminescent devices were fabricated using Langmuir-Blodgett(LB) technique with new emissive organic material. This new emissive organic material were synthesis by our teams and we called PECCP [poly(3,6-N-2ethylhexyl carbazoly cyanoterephthalidene)] which has strong electron donor group and electron acceptor group in main chain repeat unit. This material has good solubility in common organic solvent such as chloroform. THF, etc. and has a good stability in air. In here, the new emissive material is applied to Langmuir-Blodgett(LB) method because our new material has a good stability in air. Optimum conditions of film deposition were examined by a surface pressure-area( $\pi$ -A) isotherms with various factors. The LB film were deposited on a indium Tin Oxide(ITO) glass. We were investigated by measuring current-voltage(I-V) characteristics. Also we were measured the UV/visible absorption at about 410nm and PL spectrum at about 530nm. We are attempt to the electroluminescence device properties of the new emissive material by Langmuir-Blodgett(LB) technique.

• Journal of the Korea Fashion and Costume Design Association
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• v.6 no.1
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• pp.34-45
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• 2004

The purpose of the study was to investigate weaving, traditional dyeing, fiber material, pattern how carpet developing according to Turkey area for using the data that can rear to the export strategic industry for carpet production and development that is correct in culture. The result are followed: 1) Life of the age was expressed in color and pattern using according to geographical environment, climate, lifestyle, religion etc. 2) In the case of weaving, there is Kilim, Soumak that appears only weft on the surface as plane weaving without knot and carpet of knotted pile weaving and knot of carpet is duplex knot difference with carpet of the other country. 3) In the case of textile material, there is use most wool fiber that can get easily from breeded sheep by nomads. 4) In the case of dyeing, did the local traditional color to use dye extracting in dyeing material that can get easily in the area. Red that can extract in madder that can get easily in which area of Turkey, dark navy blue of indigo dye that indigo plant fermentation and cream beige that is wool's natural color were exposed representative traditional color of Turkey carpet. 5) Pattern was advanced uniquely as culture of the area; weaving person's sensitivity and desire are reflected through centuries. Amulet, riches ＆ honors, fecundity and happiness appeared most pattern in any area.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.188-188
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• 2010

Recently, there has been increased incessantly an interest in research area on energy material for electronic and electric energy generation applications. The proposed material takes an unobtrusive operation into the simple displacing mechanism using chemical impact material. However, this material makes up a radical design, based on the operation of the stoichiometry ratio on the material architecture.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.180-185
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• 2001

In order to regulate the physical characteristics of an ocean dumping material in the south-eastern East Sea, the diffusion characteristics with the observation, hydraulic experiment and numerical experiment data are investigated. The main results are as follows; (1) Spying CTD observation result of the area of Jung in the East Sea, the ocean dumping area had influenced the Tsushima warm current of high temperature and salinity. Horizontal turbulent diffusivity is 1.913${\times}$10$^{7}$ $\textrm{cm}^2$/sec by drogue tracking. (2) From the experiment of settling, the initial settling velocity of each material is 1.0∼2.7 cm/sec according to the specific gravity and initial concentration. In the pycnocline, particles didn't settle under the pycnocline any more and accumulated. It is signified that calculation of the sedimentation rate of the ocean dumping material including of vertical diffustion must be regard the pycnocline in the ocean area have well-developed pycnocline. (3) Vertical turbulent diffusivity were 2.219${\times}$10$^{-8}$∼8,874${\times}$10$^{-4}$ $\textrm{cm}^2$/sec from the experiment of settling. And, the pycnocline influenced the vertical turbulent diffusivity. (4) From the result of diffusion simulation in the East Sea, the co-concentration line of 0.05 ppm and 0.1 ppm are limited at dumping area after 200 days. The constant concentration line of 0.01 ppm is distributed to the vicinity of Ulleungdo and Tokdo, but isn't distributed to the coastal area of East Sea and southern area of Jung in the East Sea.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.753-756
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• 2001

This research made a study of MnO$_2$electrode for supercapacitor with a diffuser (Polyvinyl alcohol). Manganese dioxide was used as active material. We tried to increase specific surface area by adding PVA. Manganese dioxide was synthesized by a sol-gel method using fumaric acid and oxalic acid in low temperature with high yield. Therefore, We prepared Manganese dioxide powder. This powder was used by active materials. The electrode was made by a mixture of active material, ketjen-black which is a large specific surface area, and PVdF-co-HFP as binder agent with using Nickel mesh as current collector. Here we reported on the synthesis and electrochemical performance of a enhanced material. All active materials have been submitted to X-ray diffraction and Scanning electron microscopy.