• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.564-568
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• 2007

Gas hydrate has been attractive topic for two dedicates because it may cause the global warming, ocean hazards associated with the instability of marine slope due to the gas hydrate release as well as high potential of future energy resources. The study on gas hydrate in Ulleung basin has been performed since 1999 to explore the potential and distribution of gas hydrate offshore Korea. The numerous multi channel seismic data have been acquired and processed by Korea Institute of Geosciences and Mineral Resources (KIGAM). The results showed clearly the gas hydrate indicators such as pull up structure, bottom simulating reflector (BSR), seismic blanking zone. The prestack depth migration has been considered as fast and accurate technique to image the subsurface. In this paper, we will present both the conventional seismic data processing and apply Kirchhoff prestack depth migration for gas hydrate data set. The results will be applied for core sample collections and for proposal more detail 2D with long offset or 3D seismic exploration.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.203-207
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• 2008

Prestack depth migration is used to image for complex geological structure such as faults, folds, and subsalt. In this case, it is widely used the surface reflection data as a input data. However, the surface reflection data have intrinsic problems to image the subsalt and the salt flank due to the complex wavefields and multiples which come from overburden. For overcoming the structural defect of the surface reflection data in the imaging, I used the virtual sources in terms of seismic interferometry to image the subsurface and suppress the multiples using the velocity model of the lower part of the virtual sources. The results of the prestack depth migration using virtual source gathers and velocity model below receivers are similar geological interfaces to the results from shot gathers of the conventional ocean bottom seismic survey. And especially artificial interfaces by multiples were suppressed without applying any other data processing to eliminate multiples. This study results by numerical modeling can make a valuable imaging tool when it is applied to satisfied field data for specific condition.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.1
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• pp.85-91
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• 2004

The purpose of this study was to observe in vitro pulp chamber temperature rise during composite resin polymerization with various light-curing sources. The kinds of light-curing sources were plasma arc light(P), low heat plasma arc light, traditional low intensity halogen light, low intensity LED(L-LED), and high intensity LED(H-LED). Temperature at the tip of light guide was measured by a digital thermometer using K-type thermocouple. Occlusal cavities$(2{\times}2{\times}1.5mm)$ were so prepared in extracted human premolars as to the remaining dentin thickness was 1mm. Dentin adhesive was applied to all cavities. Experimental groups consisted of no base group, ionomer glass base group, and calcium hydroxide base group. Temperature before and after resin filling was measured. Temperature at the light guide tip was the highest with P and the lowest L-LED. Temperature before resin filling was the highest with H-LED and the lowest with L-LED. Temperature after resin filling was the highest with H-LED and the lowest with L-P and with L-LED. The lining of base partially reduced the temperature rise.

• Geophysics and Geophysical Exploration
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• v.3 no.2
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• pp.70-75
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• 2000

In the seismic migration, Kirchhoff and reverse time migration are used in general. In the reverse time migration using wave equation, two-way and one-way wave equation are applied. The approach of one-way wave equation uses approximately computed downward continuation extrapolator, it need tess amounts of calculations and core memory in compared to that of two-way wave equation. In this paper, we applied one-way wave equation to pre-stack reverse time migration. In the frequency-space domain, forward propagation of source wavefield and back propagration of measured wavefield were executed by using monochromatic one-way wave equation, and zero-lag cross correlation of two wavefield resulted in the image of subsurface. We had implemented prestack migration on a massively parallel processors (MPP) CRAYT3E, and knew the algorithm studied here is efficiently applied to the prestck migration due to its suitability for parallelization.

• Electrical & Electronic Materials
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• v.6 no.5
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• pp.428-434
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• 1993

유기물 중에서 광기능성을 가지는 벤젠, 비닐 피리딘 및 스티렌 단량체를 채택하였다. 내정전결합 유동가스형 중합장치를 사용하여 플라즈마 박막을 제조하였으며 이들의 광학특성을 분석하였다. 중합시간, 압력 및 단량체 유량을 일정하게 유지하고 방전전력을 증가시키면 스티렌 박막의 중합률은 선형적으로 증가하나 벤젠 및 비닐 피리딘 박막의 증합률은 비선형적으로 증가한다. 그리고 파장이 변화에 따른 굴절률은 1.55~1.65 정도를 나타냈다. 박막의 굴절률은 방전전력의 증가에 따라 감소하게 된다. 또한 굴절률의 변화에 대한 소멸계수(K)의 계산이 $10^{-3}$정도의 범위에 있으므로 측정 결과가 타당함을 알 수 있다.

• Journal of Veterinary Clinics
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• v.15 no.1
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• pp.146-150
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• 1998

소 림프구내의 Theileria sergenti감염을 확인하기 위하여 T. sergenti감염혈액에서 림프구를 분리한 후 중합효소연쇄반웅을 실시하였다. 또한,분리한 림프구내의 T. sergenti감 염을 증명하기 위하여 IFA test와 acridine orange stain을 실시하였다. 그 결과 다음과 같은 성적을 얻을 수 있었다. T. sergenti 감염헐액의 전혈과 림프구를 각각 생리식염수로 2배율 연 속회석하여 중합효소연쇄반응을 실시한 결과, 림프구내에서는 1,024배 회석배율까지 T. sergenti의 genomic DNA가 중폭되었으며, 전혈내에서는 256배 회석배율까지 증폭되었다. 그리 고 중합효소연쇄반응으로 T. sergenti 감염이 확인된 림프구를 이용하여 IFA test와 acridine orange 염색을 실시한 결과, 림프구내에 T. sergenti가 존재하는 것을 증명할 수있었다. 한편, 중합효소연쇄반응을 이용한 림프구내의 T. sergenti 감염의 진단 유용성을 확인하기 위하여 전 북지역에서 사육중인 소 16두를 대상으로 이들의 혈액으로 PCR 증폭을 실시하였다. 그 결과 전혈에서 genomic DNA를 취한 경우에는 3두(18.8%)만이, 그리고 림프구에서 genomic DNA를 취한 경우에는 11두(68.8%)의 소에서 T. sergenti DNA의 증폭을 관찰할 수 있었다.

• Polymer(Korea)
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• v.34 no.6
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• pp.511-516
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• 2010

The electrochemical coating of poly(3-octylthiophene) on carbon materials was studied in order to investigate the application possibility of the modified carbon materials in the photoelectronic devices. Commercial carbon paper and carbon fiber were used as substrate electrodes for electrochemical coating. The coating behaviors were analysed with the variation of monomer and electrolyte concentration, applied potential, and cycling number in cyclovoltammetry. The coating rate of poly(3-octylthiophene) formed on the substrate were proportional to the monomer and electrolyte concentration, applied potential, and cycling number with each independent exponent. The structure and morphology of electrochemically polymerized poly(3-octylthiophene) was investigated with scanning electron microscopy and FTIR reflectance measurement.

• Journal of the Korean Applied Science and Technology
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• v.13 no.2
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• pp.77-84
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• 1996

Poly(vinyl acetate)와 poly(vinyl acetate-co-2-ethylhexyl acrylate)를 여러 조건에서 semicontinuous emulsion 중합으로 합성하였다. Overall conversion, emulsion 입자크기, pH, 점도 등을 합성한 두 emulsion polymer에 대해 측정하였다. Vinyl acetate monomer에 2-ethylhexyl acrylate를 도입함으로서 emulsion 입도, 점도, 중합 속도, 유리 전이 속도가 감소함을 확인하였다.

• Nuclear Engineering and Technology
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• v.4 no.1
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• pp.23-30
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• 1972

A study on the preparation of wood-plastic combinations by gamma-ray induced polymerization is carried out. In monomer impregnation, the rates and amounts are determined for various woods. The polymerization rates of various monomers and monomer mixtures impregnated mainly domestic woods are studied varying the total gamma-dose and gamma-dose rates. The obtained data indicate that; 1) in impregnation of monomer, populus deltoides is the fastest in rate, and the most impregnated in amount 2) the general trends of polymerization of monomers ill woods is in the order of vinyl acetate--methyl metacrylate--styrene, ranging from 3 to 15 Mard of total does in rate of 4$\times$10$^4$rad/hr., thus vinyl acetate or methyl metacrylate is suitable monomer in view of polymerization rate, 3) the successful woods in combination with monomer are pinus rigida and pinus densiflora in view of polymerization rate, 4) the monomers in woods are more easily polymerized under the conditions of moderately lower does rate, 2.1$\times$10$^4$rad/hr.

• Restorative Dentistry and Endodontics
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• v.34 no.2
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• pp.103-112
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• 2009

The purpose of this study was to compare the effect of curing methods of adhesive resins and resin cements in the root canal. Crown portions of 32 single-rooted mandibular premolars were removed. Routine endodontic treatment was done, and 9 mm deep post spaces were prepared within root canals. No.3 FRC Postec posts (Ivoclar-Vivadent AG, Liechtensteih) were cemented in the post spaces by self-(SC) or light-curing (LC) using two dual-cured adhesives (Adper Scotchbond multi-purpose plus and Exite DSC )and resin cements (RelyX ARC and Variolink II). They were assigned to 4 groups (n=8): R-SC, R-LC, V-SC, V-LC group. After stored in distilled water for 24 hours, each root was transversally sectioned with 1.5 mm thick and made three slices. The specimens were subjected to push-out test in a universal testing machine (EZ Test, Shimadzu Co., Japan) with a crosshead speed of 1 mm/min. The data were analyzed with repeated ANOVA and one-way ANOVA. Also the interface of post-resin cement and resin cement-canal wall of each group was observed under FE-SEM. When fiber posts were cemented into the root canal using total-etch adhesives, the bond strength and adaptation between post and root canal dentin was affected by curing method. Self-cure of adhesives and resin cements showed higher bond strength and closer adaptation than light-cure of them.