• 한국세라믹학회지
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• 제33권12호
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• pp.1353-1364
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• 1996

Recently semiconductor doped glasses have attracted attention as nonlinear optical materials because of their large third order nonlinear optical properties. The transparent and homogeneous CdS-doped SiO2 glass thin films were obtained by the dip=coating process of the sol-gel method. Thin films were consisted of glasses containing CdS microcrystallites which were formed by dissolved Cd2+ and S2- ions in a SiO2 matrix solutions. A subsequent thermal treatment of this samples led the formation of colloidal agglomerates and finally of microcrystallites. The size of CdS microcrystallites was about 4 to 15 nm after thermal treatments at various heating conditions. From the optical absorption spectra of the CdS-doped SiO2 glass films it was found that the absorption edge was blue-shifted compared with that of the bulk CdS crystal(~2, 4 eV) and that the amount of energy shift was inversely proportional to the crystal size. And the band gap energy increased with the decrease in crystallite size indicating that the quantum size effects occured.

• The Korean Journal of Ceramics
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• 제3권4호
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• pp.249-252
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• 1997

Highly oriented ZnO thin films were fabricated by dip-coating technique using zinc acetate 2-methoxyethanol 2-aminoethanol solution as starting materials, and effects of substrates on the film's orientation were investigated. Product films were obtained by prefiring at 300, 400, 500 and 550℃ for 10 min, followed by final heat-treatment at the same temperatures as prefiring for 1h. c-axis oriented films on glass substrates were prepared by heat treatment of prefiring films at 300-550℃, while films on alumina showed polycrystalline structure. Films with c-axis orientation exhibited lower specific resistivities than those of polycrystalline films with partial crack and pore.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.629-634
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• 2000

Rockfall protection fence which is used for mitigation of rockfall hazard, has been constructed without consideration of lithology, height and dip angle of rock slope. However, those factors should be considered for the construction of the protection fence. In addition, the protection fence should be evaluated its performance by in-situ test in order to utilize the fence effectively. This is the first full sized rockfall test in Korea. For this test, the rock cut slope whose height is about 20 m and dip angle is 65 $^{\circ}$ has been chosen. Based on the preliminary simulation procedure, four different concrete balls (0.5 ton, 1.0 ton, 2.0 ton and 5.0 ton) were prepared and four different types of protection fence were constructed. The results of this test will be utilized in the establishment of rockfall protection fence construction manual.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1091-1091
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• 2005

• 대한전자공학회논문지
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• 제22권4호
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• pp.16-23
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• 1985

초음파 반사신호로 부터 매질의 특성을 끌어내고저 할 경우, 반사되어 오는 신호내에 포함되어 있는 여러 불요성분 때문에 그 정량성 평가에 어려움이 존재한다. 이에, 본 논문은 초음파 반사파에 주파수 스펙트럼의 우기적인 특성인 극소점 해석 기법을 통용하여 다층매질에서의 음달분포 정량화의 가능성을 논하고 있다. 이를 위해 컴퓨터 시뮬레이션을 행하고, 이때 고려되어야 할 간섭현상, 임피던스 차리, 감리, 두께등의 영향에 관한 검토, 그 유용성을 확인해주고 있다. 아울러 간단한 실험을 통해 그 가능성을 입양해 주고 있다.

• 센서학회지
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• 제14권6호
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• pp.402-408
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• 2005

This paper describes the optimal design of a multi-layered surface plasmon resonance sensors to meet various specifications and improve some physical parameters. Dip 3 dB bandwidth and depth were chosen as design parameters and the objective function was the norm of the difference between design parameters and target values. The design variables are thicknesses of each layer and to obtain the design parameters, the optical admittance method was employed. The (1+1) evolution strategy was employed as an optimization tool. By applying the proposed optimization procedure to a 3-layered sensor, the optimized design variables considerably improved the 3 dB bandwidth by 4.8 nm and the dip depth by 1.1 dB.

• 터널과지하공간
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• 제1권
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• pp.66-74
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• 1991

The block theory with stereographic projection was applied and analyzed on the tunnel section of Samcheok Coal Mine. The results were as follows ; 1) Prevail orientations of discontinuity of sandstone around the main driftway of Samcheok Coal Mine were $(327^{\circ},\;44^{\circ}),\;(13^{\circ},\;24^{\circ}),\;(204^{\circ},\;65^{\circ})$ and $(225^{\circ},\;77^{\circ})$ in dip and dip direction, respectively. 2) Movable blocks of the site were 0110, 0111, 1110(roof), 0100, 0110, 1110(right wall) and 0001, 1001, 1011(left wall). Because of the direction of tunnel, blocks of the left wall was safe. thus key blocks were those of the roof and the right wall. Maximum height of key block was larger than the width of the tunnel but 2m of the yielded zone is expected in general for 5m width tunnel. 3) It is shown that block theory is applicable to large cavern in hard rock analysis.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.111-118
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• 1999

This article describes the basic engineering concepts to be considered in the application of an induction heating furnace in the hot-dip galvanizing line. Experience in the Dongkuk project in Pohang, has shown that this arrangement has many advantages over the conventional method of using a combustion-gas heated furnace. Investment and operating costs are lower, the line length is much shorter, line operation is more convenient, air pollution is reduced, and the coated strip at of top-quality. As these benefits become well known, it is anticipated that the concept of induction heating will be more widely used in both new and revamped process lines. Induction heating is suitable for the production of Commercial Quality hot galvanized coils. More research is required to extend the present concept to the production of higher forming grades such as Drawing, Deep Drawing and Extra Deep Drawing Quality steels. A combination of induction heating and combustion-gas heating may lead to the way to the processing of these qualities of strip.

• 한국세라믹학회지
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• 제34권1호
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• pp.37-44
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• 1997

졸겔법중 딥코팅법을 이용하여 조성비 2Fe/Ba=5.25 졸로부터 바륨페라이트 박막을 제조하였다. 졸의 겔화과정은 4단계로 구분할 수 있으며, 8$0^{\circ}C$에서 90분간 반응시켜 제조한 졸이 코팅용 졸로서 가장 적합한 특성을 나타내었다. 박막층에 형성된 침상 형태의 입자들은 기판에 수평 하게 위치하고 있었으며, 박막 두께가 증가함에 따라 그 경향은 증가하였다. 침상형 입자의 자화용이축 방향은 장축 방향이었다.

• 한국초전도ㆍ저온공학회논문지
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• 제4권1호
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• pp.13-16
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• 2002

$SrZrO_3 $resistive oxide barriers on Ag sheathed Bi2223 tapes were prepared by the sol-gel and dip coating method to reduce AC coupling loss. The performance of the dip-coated $SrZrO_3 $ thin films was evaluated in terms of bond strength by varying the Sr/Zr mol ratio and the amount of organic vehicle (ethyl cellulose and a-terpineol) additives. The bond strength of the coatings increased as the Sr/Zr ratio decreased and the amount of organic vehicle rose, respectively. It was found that the effect of organic vehicle addition was more pronounced, suggesting that the adherence of the $SrZrO_3 $ films on Bi2223 tapes was governed primarily by the amount of organic vehicle additive.