• Journal of the Korean Chemical Society
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• v.19 no.1
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• pp.34-37
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• 1975

3-Hydroxy-canthaxanthin, reddish purple needle shaped crystals, has been isolated from the abdominal skin of Bombina Orientalis. Its structure has been established by visible and IR spectral characteristics, chromatographic behaviors, and physical and chemical properties.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.216-221
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• 2004

Linepipe steels with a low carbon acicular ferrite microstructure have been recently developed to accommodate the current transportation condition of the gas and oil industry, and they are finally applied to West- East pipeline project in China. By adopting acicular microstructure, both better formability and better toughness could be obtained due to low yield ratio and fine grained microstructure. Mechanical properties of pipe are not greatly different from those of base plates or hot coils with a microstructure of acicular ferrite. Merits of introducing higher strength steels are well known, i.e., reducing the gauge of pipe and the material cost, increasing the welding speed and decreasing construction cost because of reducing the construction period. Threfore, gas and oil industry has required higher strength steel than APIX70 grade steel. Under this background, API-X80 steel has been developed and shall be applied to the several projects. In this paper, developing stage of API-X80 steel is also presented and discussed.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.129-133
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• 2011

In this paper, a surface mounted permanent magnet synchronous motor(SPMSM) drive system for industrial sewing machine was developed. Even through a lowr-esolution encoder is used for a low cost, using a full order observer enables to estimate accurate speed and position. And it also compensates a disturbance torque caused by the belt between a load and a motor. In order to control precisely stop positions of a needle, a speed trajectory is calculated from the acceleration pattern which is obtained from the position reference. The performance of the developed system is verified by experimental results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.451-455
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• 2004

Although DC ground resistance is a good index of performance for a grounding system, it does not reflect the grounding performance during the transient states. Besides, impulse ground impedance, which is defined by a ratio of the peak value of transient ground potential rise to the peak value of impulse current, cannot be an absolute performance index due to its dependence on impulse current shape. In this paper, a grounding performance of needle-typed ground rod has been compared with simple ground rod.

• Applied Biological Chemistry
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• v.5
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• pp.53-57
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• 1964

일(一). naphthyl acetic acid를 합성(合成)하였다. 무색(無色)의 침상결정(針狀結晶)이며 M.P $131^{\circ}C$이다. 이(二). 주당(株當)의 정조량(正租量)과 분벽수(分蘗數)의 증감(增減)은 비례(比例)되지 아니하였다. 삼(三). 저농도처리(低濃度處理)에서는 정조량(正租量)의 증가(增加)를 보이고 NO. 2 집구(集區)에서 20.471%이고 고농농도처리(高濃濃度處理)에서는 무처리구(無處理區)에 비하여 주당(株當)의 정조량(正租量)은 도리어 감소(減少)하고 이집구(二集區)의 1mg/l구(區)에서 10.926%의 감소(減少)가 있었다. 사(四). 분산분석(分散分析)의 F 검정결과(檢定結果) 반복간(反覆間)에는 유의성(有意性)이 없으며 농도(濃度)의 변화(變化)는 주당정조량(株當正租量)의 증감(增減)에 유의성(有意性)이 있었다. 오(五). 삼집구(三集區)의 평균치(平均値)에 대(對)하여는 0.0005mg/l구(區)에서 11.917%의 최대증가(最大增加)를 보이고 이때의 증가회귀직선계수(增加回歸直線係數) Byx=18.275이고 반면(反面) 고농도(高濃度)인 1mg/l구(區)에서 5.572%의 감소(減少)가 있고 감소회귀직선계수(減少回歸直線係數) Byx=-12.6803이었다.

• The Korean Journal of Mycology
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• v.23 no.1 s.72
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• pp.10-13
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• 1995

The hypogeous ascomycete, Tuber aestivum subsp. uncinatum was isolated and identified for the first time in Korea from Quercus forest soil in Kyeryong-san National Park in August, 1992. The fungus is reported here with Korean name and English description. The specimen cited is deposited in herbarium of Department of Microbiology, Taejon University.

• Journal of the Korea Concrete Institute
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• v.20 no.1
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• pp.109-116
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• 2008

This study was performed to get information of self-healing mechanism in cement system and the influence of waterproofing admixtures for concrete on self-healing property. For testing, cement paste specimens cured for 7, 14 and 28 days were prepared and crushed into plate-shape pieces. Screened specimens with thickness not more than 1mm were covered with wet rags and cured in a plastic container for 7 and 28 days. After stopping hydration process of the specimens by treatment with acetone, the surfaces of specimens have been contacted with wet rags were analyzed by XRD, DSC, SEM and EDX. The analysis results showed that cement paste has self-healing property and this property is mainly affected by water. Self-healing in cement system is more effective and faster at an early stage of hydration as there is enough content of unreacted cement to make an additional hydration in this period. The results of this study also showed that waterproofing admixtures for concrete have a considerable effect on self-healing of cement pastes; i.e., they improved self-healing effect of cement and, especially, the specimen using admixture C has shown a lot of needle-like or fibrous hydration products which are estimated as ettringite. It is supposed that these ettringite products are effective to enhance self-healing in cement system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3390-3399
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• 2013

The purpose of this study was to examine the incidence rates of pressure ulcers depending on the types of healthcare organizations and to determine whether the characteristics of patients and facilities influence on the incidence of pressure ulcers in long term facilities. We analyzed data on 796,857 patients of the 2009 National Patient Sample which was extracted from to claims for medical fees to Health Insurance Review & Assesment Service(HIRA). A total of 3.2% of patients(n=25,339) had at least 1 pressure ulcer during their hospitalization. The pressure ulcer rates were highest in long term care facilities(8.2%, n=11,895) following general hospital(2.7%, n=8,052), hospital(1.7%, n= 5,059). According to logistic regression analysis, urinary incontinence (Odds ratio(OR)=2.462, 95% confidence interval(CI)=2.038-2.974), hypertension(OR=1.456, CI=1.400-1.515), peripheral vessel diseases (OR=1.357, CI=1.200-1.534) were significant predictors of pressure ulcers. As the number of diagnoses, age, and the number of doctors per 100 beds increased, the incidence of pressure ulcers increased. In addition, more number of beds was associated with fewer pressure ulcers.

• Journal of the Korean Ceramic Society
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• v.39 no.3
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• pp.245-251
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• 2002

We prepared γ-alumina beads using the amorphous alumina, obtained by fast calcination of gibbsite, and its were immersed in aqueous solution of the mixture of 21.87% nitric acid and 28.57% acetic acid. The beads thus were hydrothermaly treated at 200$^{\circ}$C for 3h, and were investigated changes of crystal, pore characteristics, $N_2$ adsorption and desorption isotherms, mechanical strengths and thermal resistance. Acicular platelet crystals of 0.1∼0.3${\mu}$m were transformed into acicular boehmite crystals of 1∼2${\mu}$m having the same crystal structure. Through this changes, we found that reversible phase transformation due to hydrothermal reaction took placed between boehmite and ${\gamma}$-alumina. In comparison to the ${\gamma}$-alumina bead before hydrothermal treatment, $N_2$ adsorption capacity was increased from 450㎖/g to 670㎖/g, and pore volume between 100${\AA}$ and 1000${\AA}$ was increased form 0.15㎖/g to 0.77㎖g, and mechanical strength was increased form 1.4MPa to 2.2MPa. Also, it showed the remarkable thermal resistance which sustained ${\theta}$-alumina crystal structure and pores between 100${\AA}$ and 1000${\AA}$ at 1000$^{\circ}$C in 40vol% steam.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.139-144
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• 2009

Laron syndrome was first described by Dr. Laron. Administration of exogenous growth hormone failed to stimulate insulin-like growth factor-I(IGF-I) production which was related to postnatal growth, because these patients lacked receptors in the liver for this hormone. The diagnosis of this syndrome is based on the typical features of GH resistance such as normal or elevated serum GH, low serum IGF-I, and impaired IGF-I response to hGH. Laron syndrome patients showed characteristically severe postnatal growth failure and markedly reduced adult height. This report describes the oral and maxillofacial manifestations of children associated with Laron syndrome. Children with Laron syndrome have several dental and skeletal irregularities. Relatively little is known of the direct effect of Laron syndrome on dental development. Further research should be needed.