• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.245-246
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• 2008

• 대한수학회지
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• 제53권1호
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• pp.233-246
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• 2016

In this paper, we introduce the class of analytic extensions of M-hyponormal operators and we study various properties of this class. We also use a special Sobolev space to show that every analytic extension of an M-hyponormal operator T is subscalar of order 2k + 2. Finally we obtain that an analytic extension of an M-hyponormal operator satisfies Weyl's theorem.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.245-246
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• 2006

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 1999년도 가을 학술발표논문집 Vol.26 No.2 (1)
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• pp.246-248
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• 1999

주 메모리 DBMS에서의 회복 시스템은 디스크에의 접근을 요하는 유일한 경우이기 때문에 시스템 전체 성능의 병목(bottleneck)이 된다. 본 논문에서는 회복 시스템에서 발생하는 주 메모리 DBMS의 병목 현상을 해소하기 위하여 복수 개의 로그 디스크를 이용하는 병렬적 로깅 기법을 제안한다. 또한 병렬적 로깅 기법을 사용하는 경우 로그 레코드들이 여로 디스크에 흩어짐으로써 시스템 재시작 시 이들간의 순서를 재규명해야 하는 오버헤드가 생기는데 이를 해결하기 위해서 병렬적 재시작 알고리즘을 제안한다.

• 대한화학회지
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• 제56권2호
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• pp.246-250
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• 2012

An efficient access, single step and environmentally benign synthesis of a new series of pyrazole containing isoxazolines derivatives were prepared by the condensation of chalcones bearing pyrazole moiety with hydroxyl amine hydrochloride in basic condition by using polyethylene glycol-400 (PEG) as a greener reaction solvent. The advantages of the present methodology are mild reaction condition and avoidance of volatile organic solvent. Furthermore, these newly synthesized compounds were screened for their antimicrobial activity against various pathogens like Escherichia coli (MTCC 2939), Salmonella typhi (MTCC 98), Staphylococcus aureus (MTCC 96), Bacillus subtilis (MTCC 441), Aspergillus niger (MTCC 281), Aspergillus flavus (MTCC 2501), Penicillium chrsogenum (MTCC 160) and Fusarium moniliformae (MTCC 156). Especially compound containing the hydroxyl group in C2-position and presence of halo (I, Br and Cl) groups as substituents at $C_3$ and $C_5$ position on the benzene nucleus showed the higher activity. Furthermore, compounds bearing methyl groups in combination with I and Br which enhanced the activity.

• Tribology and Lubricants
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• 제26권4호
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• pp.246-253
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• 2010

Friction characteristics of the brake friction materials without environmentally regulated ingredients were examined to find their role in the brake performance. Five friction materials were produced based on a nearcommercial formulation by changing the relative amount of potentially hazardous ingredients to health and environment, such as $Sb_2S_3$, potassium titanate, and brass fiber. Tribological properties of the friction materials were obtained using a scale dynamometer and Krauss type tribometer. Results showed that the excluded three ingredients played important synergetic effects on tribological properties in terms of fade resistance, wear resistance and friction effectiveness. In particular, brass fibers played important roles in the friction stability by providing excellent thermal diffusivity at the friction interface. Potassium titanate whiskers showed excellent fade resistance and wear resistance compared to the substituted barite. Antimony trisulfide, on the other hand, showed little effect on the high temperature fade resistance and wear resistance, while it increased friction effectiveness at moderate temperatures. The friction materials without the three ingredients showed severe fade, indicating antisynergy effects.

• 한국해양바이오학회지
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• 제14권1호
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• pp.1-8
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• 2022

This study examined the growth, fatty acid (FA) content, and carotenoids of a newly isolated freshwater microalga, Mychonastes sp. 246, in various culture media. The appropriate temperature and light intensity for culturing Mychonastes sp. 246 were determined as 18℃-22℃ and 200-250 µmol/m²/s using a high throughput photobioreactor. The microalgal cells were cultivated in 0.5 L bubble column photobioreactors using BG11, Bold's Basal media, and f/2 media. According to the growth results of the microalgae, BG11, among the tested media, showed the highest biomass concentrations (3.5 ± 0.1 g/L in 10 d). To enhance the biomass growth of the microalgae, the N:P ratio in BG11 was manipulated from 45:1 to 7:1 based on the stoichiometric cell composition. The biomass concentrations of Mychonastes sp. 246 grown on the manipulated BG11 (MBG) increased to 38% (4.6 ± 0.3 g/L in d) compared with the original BG11 (3.3 g/L). The FA content of the microalgae grown on the MBG was lower (8.4%) than that of the original BG11 (10.1%) while the FA compositions did not exhibit any significant differences. Furthermore, three kinds of carotenoids were identified in Mychonastes sp. 246, zeaxanthin, lutein, and β-carotene. These results suggest an effective strategy for increasing biomass concentrations, FA content, and carotenoids of microalgae by performing a simple N:P adjustment in the culture media.

• 복식문화연구
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• 제21권2호
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• pp.246-260
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• 2013

This research was carried out on women in their 20s and 30s who have overweight lower body. The subjects selected for this study were women a Rohrer index of 1.6 or higher, a waist circumference 78.5cm to 83.5cm, and a lower drop of at least 18cm. The aim is to propose a prototype of bi-stretch pants meeting demands for both functionality and aesthetic appeal. Various clothing patterns ease amount of the waist and hip circumferences and crotch depths and were developed. They had different crotch widths, and center back line angles. The results showed that the best pants patterns were ease 1cm to the total hip circumference. The front hip circumference was H/4-0.5cm, and the back hip circumference was H/4+1cm. The front crotch width was H/20+1cm, the back crotch width was H/10+3cm. No additional ease was given to the total waistline. The front waist circumference was W/4+0.5cm. The back waist circumference was W/4-0.5cm. The knee circumference was set at 44cm, the pant hem width was set at 36cm, and the pant length was set at 100cm-5cm. The findings of this research can be used as basic data for stretch pants that fit the abdomen, hips, and thighs for women in their 20s and 30s with overweight lower body.

• Journal of applied mathematics & informatics
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• 제31권1_2호
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• pp.241-246
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• 2013

Choi [1] identified and characterized the limiting diffusion of this diploid model by defining discrete generator for the rescaled Markov chain. In this note, we define the operator of projection $S_t$ on limiting diffusion and new measure $dQ=S_tdP$. We show the martingale property on this operator and measure. Also we conclude that the martingale problem for diffusion operator of projection is well-posed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.245-246
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• 2007