• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.7
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• pp.995-1006
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• 2003

The suitability of high-order accurate, centered and upwind-biased compact difference schemes for large eddy simulation is evaluated by a dynamic analysis. Large eddy simulation of isotropic turbulence is performed with various dissipative and non-dissipative schemes to investigate the effect of numerical dissipation on the resolved solutions. It is shown by the present dynamic analysis that upwind schemes reduce the aliasing error and increase the finite differencing error. The existence of optimal upwind scheme that minimizes total numerical error is verified. It is also shown that the finite differencing error from numerical dissipation is the leading source of numerical errors by upwind schemes. Simulations of a turbulent channel flow are conducted to show the existence of the optimal upwind scheme.

• Journal of Microbiology
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• v.34 no.1
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• pp.1-6
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• 1996

The nucleic acid of Synechococcus sp. cyanophage was identified as double-stranded DNA by the result of digestion with enzymes such as exonucleases, DNase, and S1 nuclease, and by acridine orange staining. The cyanophage DNA was cleaved with several restriciton ehdonucleases such as ApaI, BamHI, Bg/II, HaeIII, Eco RI, HindIII, PstI, AND aPAI gave the clearest sets of bands on agarose gels and the fragment numbers for each were 12, 20, 29, 20, and 7, respectively. The sums of the size from Bam HI and PstI digestions were estimated approximately 227$\pm$4 kb, which are in agreement with the result of the pulsed field gel electrphoresis. This virus is thought to have the largest genosome among those of known cyanophages, which corresponds to the largest haed ot 90 nm when compared with the head sizes of cyanophages discovered since 1963.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.306-308
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• 2005

염분농도에 따른 발아특성은 쪽제비싸리, Perennial ryegrass의 경우 $0.4\%$ 이상 NaCl 농도에서 발아율과 유아 및 유근 길이가 급격히 감소하였으며, Creeping red fescue는 $0.2\%$ 이상 NaCl 농도에서 매우 급격한 생육저하가 일어났다. 외래초종의 초장 분석결과 Mixture III> Mixture IV> Mixture II> Mixture I의 순이었고, 재래 초$\cdot$목본의 경우는 외래초종의 초장이 길수록 길이가 짧아지는 경향을 나타냈으며, Mixture I> Mixture II> Mixture IV> Mixture III의 순이었다.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.47-49
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• 2003

At present, the Korean electricity industry is undergoing restructuring and the CBP market is being operated preparing for TWBP market open. As the circumstance of the traditional system is changed according to power system deregulation the unique market simulator is needed to analyze and study an electricity market. In this paper, we implement the main two modules of unique market simulator(PEXSIM) and introduce the characteristics of PEXSIM focused on the M-SIM and P-SIM.

• Imaging Science in Dentistry
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• v.37 no.4
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• pp.217-220
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• 2007

Purpose: The purpose of this study was to compare the location of the mandibular canal in Class III malocclusion to its location in normal occlusion for adults. Materials and Methods: For this study 32 skeletal Class III patients and 26 normal patients were observed. Four measurements were taken on cross sectional tomography between the first and second molars: the distance from the mandibular canal to the inner surface of both the buccal and lingual cortices, the distance from the mandibular canal to the inferior border of the mandible, and the buccolingual width of the mandible. The buccolingual location of the canals was classified as lingual, central, or buccal. Each measurement was analyzed with an independent t test to compare Class III malocclusion to normal occlusion. Results: Compared to the control group, the prognathic group had a shorter distance from the canal to the inner surface of the lingual cortex and to the base of the mandible. A higher percentage of the canals were located lingually in the prognathic group. Conclusion: This study showed that the mandibular canal was located more lingually and inferiorly in prognathic patients than in patients with normal occlusion. These results could help surgeons to reduce injuries to the inferior alveolar nerve.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3177-3183
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• 2012

The carbon nanofibers (CNFs) used in this study were synthesized with an iron catalyst and ethylene as a carbon source. A concentration of 30 wt % iron(III) acetylacetonate was dissolved in resol type phenol resin and polyurethane foam was put into the solution. The sample was calendered after being cured at $80^{\circ}C$ in air for 24 h. Stabilization and carbonization of the resol type phenol resin and reduction of the $Fe^{3+}$ were completed in a high-temperature furnace by the following steps: 1) heating to $600^{\circ}C$ at a rate of $10^{\circ}C/min$ with a mixture of $H_2/N_2$ for 4 h to reduce the $Fe^{3+}$ to Fe; 2) heating to $1000^{\circ}C$ in $N_2$ at a rate $10^{\circ}C/min$ for 30 minutes for pyrolysis; 3) synthesizing CNFs in a mixture of 20.1% ethylene and $H_2/N_2$ at $700^{\circ}C$ for 2 h using a CVD process. Finally, the structural characterization of the CNFs was performed by scanning electron microscopy and a synthesis analysis was carried out using energy dispersive spectroscopy and X-ray photoelectron spectroscopy. Specific surface area analysis of the CNFs was also performed by $N_2$-sorption.

• Journal of Korean Biological Nursing Science
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• v.11 no.2
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• pp.99-104
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• 2009

Purpose: An animal model of pressure ulcers was experimentally-induced with the use of greater trochanter of rats. Methods: Twelve male Sprague-Dawley rats were used in this study and they were randomly divided into 4 groups: Group I (n=3, 120 mmHg, 2 hr), Group II (n=3, 120 mmHg, 3 hr), Group III (n=3, 140 mmHg, 3 hr) and Group IV (n=3, 140 mmHg, 4 hr). The rats were anesthetized with 100 mg/kg of ketamine. The pressure ulcers were induced by using a personally-designed pressing apparatus. After 5 days, the wounds were photographed and excised. Results: After 5 days of induced pressure ulcers, it was observed that Group I and Group II responded with Grade I and Grade II, respectively, while Group III and Group IV responded with Grade III. Conclusion: According to the result of this study, it can be concluded that the pressure ulcers were induced the characteristic grades of pressure ulcer classification by adjusting the degree and the duration of compression.

• Analytical Science and Technology
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• v.10 no.4
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• pp.274-281
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• 1997

Methods to determine terbium(III) ion in aqueous solution by measuring the enhanced fluorescence intensity of terbium(III)-terephthalic acid(TPA) complex ion have been studied. The optimum analytical conditions for pH, excitation wavelength and concentration of TPA were found to be 6.0, 260nm and $4.0{\times}10^{-4}M$, respectively. The fluorescence intensity of the terbium(III) complex ion was further increased with addition of trioctylphosphine oxide (TOPO). In this case Triton X-100 was used to dissolve TOPO in aqueous solution. When TOPO was used, the optimum analytical conditions for pH, excitation wavelength, and concentrations of TPA, TOPO and Triton X-100 were found to be 4.5, 285nm. $4.0{\times}10^{-4}M$, $5.0{\times}10^{-5}M$, and 0.05%, respectively. Under the optimum experimental conditions, calibration curve for Tb(III) was linear over the range from $4.0{\times}10^{-8}M$ to $4.0{\times}10^{-5}M$ and the detection limit was $4.0{\times}10^{-8}M$. When TOPO was used, the concentration range of linear response, and the detection limit were $4.0{\times}10^{-9}M$ to $2.0{\times}10^{-6}M$, and $4.0{\times}10^{-9}M$, respectively. Effects of interferences from various cations for the determination of terbium(III) ion were also investigated.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.26 no.4
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• pp.1-14
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• 2013

Objectives : The purpose of this study is to investigate effects of Syzygium aromaticum (SAE) spread on the allergic contact dermatitis caused by 2,4-dinitro-chlorobezene (DNCB). Methods : Forty-two mice were divided into six groups ; normal, negative control (DNCB-treated), positive control (DNCB + 1% pimecrolimus), experimental group I, II and III. control and experimental groups were induced allergic contact dermatitis by DNCB. Experimental group I(DNCB + 0.2% SAE), II(DNCB + 1% SAE) and III(DNCB + 5% SAE) were spread SAE and positive control was spread the 1% pimecrolimus. In this study, effect of SAE on clinical aspects on the skin, histopathological change, the blood level of IgE, cytokines, histamine were investigated. In addition, effect of SAE on spleen $CD4^+/CD8^+$ T cell subset was investigated. Results : 1. In experimental group I, II and III, erythemas and edema were more reduced than negative control. 2. In experimental group I, II and III inflammatory edema and the numbers of infiltrated inflammatory cells were more reduced than negative control. 3. In experimental group I, II and III, clinical skin score was more reduced than negative control. 4. In experimental group II and III, the thickness of skin was statistically significant reduced than negative control. 5. In experimental group II and III, histamine release was statistically significant reduced than negative control in dose-dependantly. 6. In experimental group II and III, cytokines (IL-1${\beta}$, TNF-${\alpha}$, IL-4, IL-6, IL-10) were statistically significant reduced than negative control in dose-dependantly. 7. In experimental group I, II and III, the level of total IgE was statistically significant reduced than negative control in dose-dependantly. 8. In experimental group III, $CD4^+$ and $CD8^+$ T cells were statistically significant decreased similar to the positive control. Conclusions : According to above experiments, Syzygium aromaticum(SAE) was effective on allergic contact dermatitis.

• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.466-477
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• 1998

Twenty-two Phellinus strains were characterized using colony morphologies and polymerase chain reaction (PCR) to divide into Phellinus linteus. There were some differences in mycelial growth and colony shapes among the strains when they were grown on various media such as PDA, MCM, MEA and YM. Phellinus linteus was slowly growing, formed golden-yellow colony, and produced blue pigment on PDA media. When the regions of internal transcribed spacer (ITS) were amplified from ribosomal RNA (rRNA) coding genes of P. igniarius and P. linteus strains by means of PCR, two types of band (700 bp and 800 bp) were appeared, respectively. For the amplified intergenic region I (IGRI), P. igniarius strains showed a different band among 500, 600, 700 and 800 bp according to the strains, whereas P. linteus strains did one specific band of 700 bp. By polymorphism analysis after digesting the amplified products with 6 different restriction enzymes, a band specific to P. linteus was generated when the products for ITS region were digested with HaeIII, suggesting that the enzyme digestion could provide effective method to distinguish between P. igniarius and P. linteus. And also, the analysis of genetic relationship showed that the genetic similarities were 89% and 95% in P. igniarius and P. linteus strains, respectively. Random amplification polymorphic DNA (RAPD) analysis using multiple primer sets and arbitrarily primed PCR (AP-PCR) with ITS3 primer could also result in a reproducible way to identify P. linteus strains.