• Journal of the Korea Society of Computer and Information
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• v.18 no.3
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• pp.47-57
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• 2013

Location privacy has been a serious concern for mobile users who use location-based services to acquire geographical location continuously. Spatial cloaking technique is a well-known privacy preserving method, which blurs an exact user location into a cloaked area to meet privacy requirements. However, cloaking for continuous moving object suffers from cloaked area size problem as it is unlikely for all objects travel in the same direction. In this paper, we propose a grid-based privacy preservation method with an improved Earth Mover's Distance(EMD) metric weight update scheme for semantic cloaking. We also define a representative cloaking area which protects continuous location privacy for moving users. Experimental implementation and evaluation exhibit that our proposed method renders good efficiency and scalability in cloaking processing time and area size control. We also show that our proposed method outperforms the existing method by successfully protects location privacy of continuous moving objects against various adversaries.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.304-310
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• 1986

A. calcoaceticus C10 grown on cyclohexanol as sole source of carbon and energy produced cyclohexanol dehydrogenase(CDH) and glucose dehydrogenase (GDH) concomitantly. CDH and GDH were different in coenzyme, induction and electrophoretic patterns. CDH depended for activity on $NAD^+$ only, while GDH required $NAD^+$ or $NADP^+$ alternatively. CDH was produced in the medium added cyclohexanol, but GDH was produced in various media such as LB, LB added 0.2% glucose or cyclohexanol and cyclohexanol medium. Productivity of CDH in A. calcoaceticus C10 was enhanced about 8 times by the addition of 0.2% cyclohexanol to LB medium after 4 hours as much as LB medium only. Production of CDH was induced by cyclohexanol, cyclohexanone, cyclohexan-1,2-diol and cyclohexene oxide, but not induced by ${\varepsilon}-caprolactone$ and adipate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.640-645
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• 2011

The purpose of this article is to investigate ways of making the cloze test more valid as an English proficiency test so that it can provide a better format for the cloze test especially to the non-native teachers in EFL environments. This investigation identifies ways of validity in terms of materials, deletion rates, item characteristics and scoring methods used in cloze tests. An increase in test validity can be accomplished by knowing how the four factors affect the cloze test results and how to manipulate them. Practical suggestions are provided for teachers to design a cloze test. Teachers can develop the reliability and validity of cloze tests by manipulating the four factors. In seeking a more valid and reliable cloze format, this research gives some suggestions based on a literature review. We can conclude that a cloze test can be valid only when teachers are aware of the factors which affect the test result and the ways to handle the factors to make the test appropriate for their test purposes.

• 월간산업보건
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• s.38
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• pp.15-23
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• 1991

• 대한치주과학회:학술대회논문집
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• 1997.11a
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• pp.39-39
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• 1997

• 발명특허
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• v.34 no.5
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• pp.36-40
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• 2009

• Applied Biological Chemistry
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• v.48 no.1
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• pp.60-64
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• 2005

Yogurt base was prepared from skim milk added with $0.2{\sim}1.0%\;(w/v)$ chlorella powder and fermented with lactic acid bacteria (the mixed strain of Lactobacillus acidophilus, Bifidobacterium longum and Streptococcus thermophilus) at $40^{\circ}C$ for $12{\sim}18\;h$. Quality characteristics of the yogurt were evaluated in terms of acid production (pH and titratable acidity), number of viable cells, viscosity and sensory properties. The addition of chlorella powder stimulated the growth of lactic acid bacteria and remarkably enhanced the acid production. After 12 h incubation, titratable acidity of chlorella yogurt was $1.16{\sim}1.33%$ and was higher than that (1.02%) of yogurt made with only skim milk. However, the viscosity of yogurt was decreased by the addition of chlorella powder. The sensory score of yogurt added with 0.2% chlorella powder was similar to ordinary yogurt in taste and overall acceptability. When chlorella yogurt was kept at $4^{\circ}C$ for 15 days, its quality-keeping properties except for number of viable cells were relatively good. According to sensory score and storage ability, the optimum concentration of chlorella powder was around 0.2%.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.83-91
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• 2008

Dental caries which is one of the most common chronic disease complexly developed by the action of oral bacteria, diet, and host factor. Various prevention program enhance resistance of demineralization and reduce the acidogenecity of oral bacteria have been introduced, representative material is fluoride and chlorhexidine. The purpose of the study was to evaluate and compare effectiveness of fluoride varnish and chlorhexidine varnish in vivo. Bovine tooth specimens were implanted in the lower space maintainers and applied with fluoride varnish and chlorhexidine varnish. After seven days in oral environment, metal mesh was covered to make similar condition of plaque accumulation and induce caries. All specimens were analysed by EPMA to evaluate quantitative change of Ca, P and by polarized microscope to identify histological changes. The results were as follows : After initial artificial caries induction in the mouth, there were remarkable enamel caries lesion in the control group under polarized light microscopy. The highest amount of mineral decrease were showed in control group. No statistically significant mineral decrease were showed in fluoride varnish group, while chlorhexidine varnish group showed only significant decrease of P(P<0.05). In conclusion both fluoride varnish and chlorhexidine varnish seemed to be effective for protecting enamel surface from caries activity, although fluoride varnish has more anticariogenic effect than chlorhexidine varnish.

• Journal of Environmental Science International
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• v.4 no.4
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• pp.357-365
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• 1995

The use of chlorinated water in swimming pools produces elevated chloroform levels in the water and air of the pools which can cause chloroform body burden of swimming individuals. Present study confirmed the chloroform body burdens from a 40-min swimming and evaluated the decay of chloroform breath concentration after the cessation of a 60-min swimming. Air and water concentrations were measured in the pools. The water and air chloroform concentrations ranged from 18.1 to 25.3 ${mu}g/l$ and from 30.9 to 60.7 ${\mu}g/m3$ for the confirmation study, respectively. The breath level after 40-min swimming was about 64 to 266 folds higher than the corresponding background breath. The breath concentration after the 40-min swimming ranged from 10.5 to 21.3 ${\mu}g/m3$, while that prior to the corresponding swimming ranged from 0.07 to 0.19 ${\mu}g/m3$. In addition, the post-exposure breath level varied with the subjects who swam in the pool on the same visiting day. Breath concentration increased gradually during 60-min swimming, then decreased rapidly within 5 minutes after the cessation of exposure, after that, decreased slowly, and finally approached to a background breath level at 1-2 hr after exposure.

• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.87-94
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• 1996

한국산 동백나무겨우살이(Pseudixus japonicus) 추출물의 암치료를 위한 생약으로서 활성 유효성을 검증하기 위하여 메탄올, 석유에테르, 클로로포름, 초산 에틸 용매로 순차적으로 추출하여 겨우살이 추출물의 다섯 가지 분획을 얻어, 이에 대하여 in vitro로 1차와 2차 검색 시스템을 사용해 항암활성 성분을 체계적으로 검색하였다. 다섯 가지 분획 중 클로로포름 가용성 분획이 1차 검색 세포인 $P388D_1$에 대해 가장 높은 항암활성을 나타내어 MSB1, NIH/3T3, SNU-1, SNU-C2A 등 2차 검색 시스템에 대해 클로로포름 가용성 분획의 항암활성을 다양한 농도하에서 비교 검색하였다. 혈액암 세포중 특히 $P388D_1$의 생장이 클로로포름 추출물에 의해 강하게 저해되었으며, 형질전환된 생쥐의 태아 섬유아세포와 사람의 대장암, 위암세포들도 어느 정도의 생육저해를 나타내었다. 이 클로로포름 가용성 분획의 주성분은 원소분석, 발색시약과의 반응, IR, GC-MS, $^{13}C$-NMR의 스펙트럼의 결과로 세 종류의 알칼로이드 화합물로 확인되었고, 부성분으로는 지방산 메틸 에스테르와 프탈라이드 화합물이 MS 스펙트럼을 통해 동정되었다.