• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1653-1653
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• 2006

• Journal of the Korean Chemical Society
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• v.22 no.2
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• pp.86-94
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• 1978

The crystal and molecular structure of theophylline hydrochloride has been determined from X-ray data by Patterson techniques. The structure has been refined by block-diagonal least-squares and Fourier synthesis on three dimensional data. The unit cell is orthorhombic, space group $P_{na21}$, with a = 14.01, b = 11.49, c = 6.77${\AA}$, and contains four molecules. The final R value based on 743 observed reflexions is 12.2%. The intramolecular distances are similar to those in other compounds containing a purine or pyrimidine group. The molecules are nearly planar and are stacked in layers parallel to the (001)plane. The chlorine atom is coordinated to N(1) atom at a distance of 3.06${\AA}$. The structure is stabilized mainly by van der Waals interactions; however, a short N${\cdot}{\cdot}{\cdot}$Cl contact of length $3.06\AA$, which is slightly less than the expected van der Waals separation, suggest that weak charge transfer interaction may be present. The relationship between this structure and the known structures of theophylline monohydrate and caffeine monohydrate are discussed.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.407-414
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• 2010

Until now, the pore size distribution, PSD, of soil profile has been calculated from soil moisture characteristic data by water release method or mercury porosimetry using the capillary rise equation. But the current methods are often difficult to use and time consuming. Thus, in this work, theoretical framework for an easy and fast technique was suggested to estimate the PSD from unsaturated hydraulic conductivity data in an undisturbed field soil profile. In this study, unsaturated hydraulic conductivity data were collected and simulated by the variation of soil parameters in the given boundary conditions (Brooks and Corey soil parameters, ${\alpha}_{BC}=1-5L^{-1}$, b = 1 - 10; van Genuchten soil parameters, ${\alpha}_{VG}=0.001-1.0L^{-1}$, m = 0.1 - 0.9). Then, $K_s$ (1.0 cm $h^{-1})$ was used as the fixed input parameter for the simulation of each models. The PSDs were estimated from the collected K(h) data by model simulation. In the simulation of Brooks-Corey parameter, the saturated hydraulic conductivity, $K_s$, played a role of scaling factor for unsaturated hydraulic conductivity, K(h) Changes of parameter b explained the shape of PSD curve of soil intimately, and a ${\alpha}_{BC}$ affected on the sensitivity of PSD curve. In the case of van Genuchten model, $K_s$ and ${\alpha}_{VG}$ played the role of scaling factor for a vertical axis and a horizontal axis, respectively. Parameter m described the shape of PSD curve and K(h) systematically. This study suggests that the new theoretical technique can be applied to the in situ prediction of PSD in undisturbed field soil.

• Environmental Engineering Research
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• v.18 no.3
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• pp.151-156
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• 2013

Several soil properties were studied from three young created mitigation wetlands (<10 years old), which were hydrologically comparable in the Piedmont region of Virginia. The properties included soil organic matter (SOM), soil organic carbon (SOC), pH, gravimetric soil moisture, and bulk density ($D_b$). No significant differences were found in the soil properties between the wetlands, except SOM and SOC. SOM and SOC indicated a slight increase with wetland age; the increase was more evident with SOC. Only about a half of SOC variability found in the wetlands was explained by SOM ($R^2$ = 0.499, p < 0.05). The majority of the ratios of SOM to SOC for these silt-loam soils ranged from 2.0 to 3.5, which was higher than the 1.724 Van Bemmelen factor, commonly applied for the conversion of SOM into SOC in estimating the carbon storage or accumulation capacity of wetlands. The results may caution the use of the conversion factor, which may lead to an overestimation of carbon sequestration potentials of newly created wetlands. SOC, but not SOM, was also correlated to $D_b$, which indicates soil compaction typical of most created wetlands that might limit vegetation growth and biomass production, eventually affecting carbon accumulation in the created wetlands.

• Korean Journal of Crystallography
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• v.6 no.2
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• pp.63-68
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• 1995

The crystal structure of fenothiocarb(S-4-phenoxybutyl dimethylthiocarbamate), C13H19NO2S is monoclinic, space group P21/c, a=9.045(1)Å, b=14.577(2)Å, c=10.727(2)Å, β=103.56(1)°, Z=4, V=1375.20(6)Å3, Dc=1.23g/cm3, λ(Mo-Kα)=0.71069Å, μ=2.3cm-1, F(000)=544, temperature : 293±3K, R=0.049 for 1543 unique observed reflections. The structure was determined by direct method and refined by full-matrix least squares method. The molecules are contacted to the c axis with two fold screw and van der Waales force.

• Nuclear Engineering and Technology
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• v.4 no.2
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• pp.116-131
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• 1972

A fast neutron time-of-flight spectrometer has been constructed with suitable choice of target thickness and proton bombarding energy in Li$^{7}$ (p, n) Be$^{7}$ nuclear reaction for a continuous keV spectrum of neutrons at 0 degree in 1-nsec pulse from a Van do Graaff and a time-pick-up fast neutron detector assembled with a 5 mm-thick 92% enriched B$^{10}$ slab and four heavily shielded 4＂$\times$3＂ NaI scintillation detectors. Energy resolution of this spectrometer is better than 0.3% at 50 keV and the signal-to-background ratio is also improved. Total cross section measurements of several separated single isotopes have been carried out with this spectrometer and analyzed by Rmaxtrix multi-level computer code. The spin values and resonance parameters of each individual resonances are given.

• Proceedings of the Korea Association of Information Systems Conference
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• 2000.11a
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• pp.6-11
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• 2000

수출입 관련 항만물류업무 처리의 효율화를 위해 1996년부터 도입된 EDI는 서류없이 각종 항만물류 및 통관업무를 효율적으로 처리하는데 큰 기여를 하고 있다. 그러나 기존의 방식은 VAN EDI 로써 폐쇄적인 VAN 망을 통하여 EDI VAN사업자가 사용자의 EDI문서를 관련 정부기관에 중계만을 하여 EDI문서에 나타난 각종 데이터의 누적을 통한 물류정보서비스는 제공되고 있지 않다. 한편, EDI를 수신한 각 정부기관에서는 필요한 물류요약정보를 얻기 위해 해당 EDI 문서에서 추출한 데이터를 저장하는 운영 데이터베이스에 접근하여 필요한 요약 정보를 리포트 형태로 프로그램하여 생성하고 있어 정보제공의 시간지연과 프로그램 업무의 과중 및 운영 데이터베이스에 대한 부하가 발생하고 있다. 본 논문의 목적은 이러한 상황에서 수출입 항만물류와 관련한 다차원 정보를 실시간제공하기 위한 데이터웨어하우스를 구축하는데 있다. 일반적으로 데이터웨어하우스는 운영데이터베이스로부터 다차원 구조의 데이터웨어하우스로 데이터를 추출, 전환, 복사함으로써 이루어지지만, 본 연구에서는 EDI 수신 기관의 운영데이터베이스보다 더 원천 데이터인EDI 문서로부터 데이터웨어하우스로 데이터 변환을 함으로써 항만물류 데이터웨어하우스의 데이터 추출 단계를 한 단계 줄였다. 현재 VAN EDI 방식은 그 폐쇄성과 비용 때문에 향후 인터넷을 이용한 XML/EDI로 기술 이전될 것이 예상되며 이러한 상황에서VAN EDI 포맷이 아닌 XML/EDI 문서로 부터 데이터웨어하우스로의 전환을 구현하였다. 본 연구에서는 관세청의 수출통관 EDI에 대해 이를 XML/EDI 로 XML 스키마를 정의하고 이로 생성된 XML 문서를 SQL 서버로 구현된 OLAP 용 데이터웨어하우스로 전환하였다. 본 연구를 통해 XML을 이용한 EDI체제에서 전자문서전송기능과 정보제공기능을 위한 데이터웨어하우스의 연동을 동해 EDI시스템을 다차원 의사결정정보 시스템과 통합하게 하여, 향후 인터넷 기반 XML/EDI 중계서비스에 있어 물류정보서비스도 원활하게 제공할 수 있게될 것으로 기대된다.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1791-1793
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• 2012

• Advances in nano research
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• v.6 no.2
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• pp.135-145
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• 2018

This work represents the study of the vibration response of the double walled carbon nanotubes (DWCNT) for various boundary conditions. The inner and outer carbon nanotubes are modeled as two individual Euler-Bernoulli's elastic beams interacting each other by Van der waals force. Differential transform method (DTM) is used as a numerical method to solve the governing differential equations and associated boundary conditions. The influence of Winkler elastic medium on vibration frequency is also examined and results are interpreted. MATLAB is used as a tool for solving the governing differential equations. The fundamental natural frequencies are validating with those available in literature and observed a good agreement between them.

• Bulletin of the Korean Mathematical Society
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• v.54 no.5
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• pp.1527-1575
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• 2017

In a spirit of Givental's constructions Batyrev, Ciocan-Fontanine, Kim, and van Straten suggested Landau-Ginzburg models for smooth Fano complete intersections in Grassmannians and partial flag varieties as certain complete intersections in complex tori equipped with special functions called superpotentials. We provide a particular algorithm for constructing birational isomorphisms of these models for complete intersections in Grassmannians of planes with complex tori. In this case the superpotentials are given by Laurent polynomials. We study Givental's integrals for Landau-Ginzburg models suggested by Batyrev, Ciocan-Fontanine, Kim, and van Straten and show that they are periods for pencils of fibers of maps provided by Laurent polynomials we obtain. The algorithm we provide after minor modifications can be applied in a more general context.