• 한국물환경학회지
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• 제24권2호
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• pp.214-220
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• 2008

Nitrifying bacteria were detected by fluorescent in situ hybridization (FISH) method at 6 sampling sites with different eutrophication degree in the Nak-Dong River and their tributaries. And conventional physico-chemical parameters including $NH_4-N$, $NO_3-N$, and TN were determined concurrently. In rainy period (July), there was no noticeable difference between the number of ammonia/nitrite-oxidizing bacteria detected at each site except Sang-Ju and the ratio of nitrifying bacteria to total counts stained by DAPI varied in 6~33%. By contrast, in the dry period (October), both of bacterial population was increased differently and the ratio of nitrifying bacteria to total counts ranged more widely from 6% in heavily polluted water zone, Hwa-Won to 60% in upper tributary with high agricultural land use. Byung-Sung-Chun. In January, the numbers of ammonia-oxidizing bacteria was reduced up to one tenth, while those of nitrite-oxidizing bacteria was apparently increased maybe due to high DO and low DOC.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.147-157
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• 1996

Natural gas is gaining more attraction as a future fuel in particular both for environmental protection and energy conservation. In order to bring about more widespread use of gaseous engines, the technology capable of achieving output and efficiency performance equivalent to that of diesel engines needs to be developed. In the present paper, the requirements of the pilot torch from pre-chamber for ensuring ignition and promoting combustion are discussed by means of taking high-speed flame photography and system can run with leaner mixture of various fuels comparing to the electric plug ignition system cause the ignition delay period ignited with the torch and the combustion period are very short in spite of changing A/F of gaseous fuels in the main chamber. However, the suitable piston-cavity design for the use of lower-hydrocarbon fuels such as propane and butane must be discussed increasingly in the mear future.

• 한방안이비인후피부과학회지
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• 제15권1호
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• pp.151-161
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• 2002

For the purpose of treating for urticaria, they orderly use LI, B, GV in acute stage, and use the kyunghyul of Sp, CV, P, Liv, L in chronic stage. we can presume that in the past, they must select these kyunglak and kyunghyul by the phase and the period of the urticaria. To approach to treating urticaria, it is necessary the selecting of kyunghyul by the phase and period of the urticaria.

• 대한가정학회지
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• 제42권9호
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• pp.195-212
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• 2004

The purpose of this study was to analyze consumers' perceived risk and information search behaviors in internet shopping. For this purpose, survey was conducted on 302 consumers in their 20s and 30s who had internet shopping experience. This study found that consumers' perceived risk was significantly related to their gender, educational level, income, credit card use, period of internet un, number of internet shopping experiences, and purchased product. Consumers' search behaviors were also significantly affected by gender, age, educational level, income, period of internet use, and purchased product. In addition, a higher level of consumers' perceived risk was significantly related to the amount of information search on product attributes themselves rather than on general information search such as the number of sites or the number of brands.

• 충청수학회지
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• 제21권2호
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• pp.259-268
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• 2008

To the design of secret key, there are two types of basic approaches called the tame approach and the wild approach. In the tame approach we try to use only simple primitives such as linear feedback shift registers and to prove mathematical theorems about their cryptographic properties. In the wild approach we try to use crazy compositions of operations which mix a variety of domains in a nonlinear and nonalgebraic way. There are several papers which try to bridge this gap by considering semi-wild constructions. A T-function on n-bit words plays an important role in semi-wild constructions. In this paper we study the invertibility and the period of some T-functions. Especially we characterize some polynomials which has a single cycle property.

• 디지털융복합연구
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• 제11권12호
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• pp.569-576
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• 2013

본 연구는 우리나라 여성을 대상으로 경구피임약 복용과 치주질환의 관련성을 분석하여 피임약이 치주질환에 미치는 영향을 파악하고자 하였다. 연구자료는 제4기 국민건강영양조사 자료 중 2008년과 2009년 결과를 이용하였고, 19-50세 폐경 전 가임여성 1,101명을 대상자로 선정하였다. 인구사회경제적 요인과 구강보건행태, 피임약 복용기간 및 치주질환 상태를 파악하여 chi-square 검정과 logistic regression 분석을 통해 경구피임약 복용과 치주질환과의 관련성을 조사하였다. 그 결과, 인구사회경제적 요인 중 연령과 결혼여부, 흡연상태가 경구피임약 복용과 통계적인 유의성을 나타내었다. 현재 경구피임약 복용여부와 치은조직 상태는 연관성이 없는 것으로 확인되었다. 치주질환 유병율은 연령에 따라 증가하였지만, 피임약 복용기간과 흡연, 칫솔질과 치간관리를 포함한 구강보건형태와는 통계적으로 유의한 차이를 보이지 않았다. 마지막으로 logistic regression 분석 결과, 혼란변수 보정여부에 따라 큰 차이 없이 치주질환은 경구피임약 복용여부 및 복용기간과 관련성이 없는 것으로 확인되었다.

• Journal of Acupuncture Research
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• 제33권1호
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• pp.57-68
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• 2016

Objectives : The purpose of this study was to investigate the correlation between patients' characteristics and the beginning period of improvement, as well as contribute to the efficient management of Bell's palsy patients. Methods : The subjects were 94 patients with Bell's palsy. This study was carried out through the use of an administrative database that included patients' characteristics and clinical information. The analysis of the beginning period of improvement by gender, hypertension, diabetes, drinking history, smoking history and facial palsy history was conducted by independent sample t-test. The analysis of the beginning period of improvement by age, House-Brackmann grade, Yanagihara scale and period receiving Korean medical treatment was conducted by Pearson's correlation analysis. Further analysis of the beginning period of improvement by associated symptoms and seasons was conducted by one-way analysis of variance. Results : 1. Significant correlations were not found between the beginning period of improvement and gender, age, season, smoking history, drinking history, facial palsy history, House-Brackmann grade, Yanagihara scale, hypertension, diabetes or associated symptoms. 2. There was significant correlation between the period of receiving Korean medical treatment and the beginning period of improvement. Conclusion : In this study, the earlier that patients received korean medicine treatment after onset, the earlier that the beginning period of improvement could be seen. Therefore, for the efficient management of facial paralysis patients, it is expected to help secure a baseline.

• 한국수자원학회논문집
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• 제30권6호
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• pp.709-720
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• 1997

다목적 댐의 홍수기 저수지 운영에 있어 댐 규정에 명시된 홍수조절용량이 부족하다고 판단되는 경우, 한정된 저수공간의 탄력적인 이용방안을 강구하여 추가적인 홍수조절용량을 확보하여야 한다. 본 연구에서는 홍수기의 기상특성을 반영하여 홍수기를 시기적으로 구분하고, 구분된 홍수기간별로 각각의 이수목적수위와 치수목적수위를 검토하였다. 검토된 결과를 바탕으로 서로 상반되는 이수와 치수를 함께 고려할 수 있는 방안을 강구하였으며, 이로부터 결정된 홍수기 댐 운영수위를 홍수기 가변제한수위라 정의하였다. 홍수기 가변제한수위를 결정하는 일련의 절차에 대해 대청 다목적 댐을 대상으로 적용하고 그 결과를 분석하였다.

• 한국학교수학회논문집
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• 제21권2호
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• pp.161-181
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• 2018

이 논문에서는 1876년에서 1910년에 이르는 개화기에 국가적 차원에서 일어난 초등수학교육의 변화를 정리하였다. 이를 위해 개화기를 갑오개혁이전, 갑오개혁, 통감부시기로 구분하고 각 시기별로 초등수학교육의 주요 변화를 살펴보았다. 갑오개혁이전시기부터 산술교육의 필요성이 인식되었으며, 갑오개혁시기에 산술교육은 본격적으로 국가교육과정이 되었다. 특히 갑오개혁시기에는 국한문혼용의 초등수학교과서가 발간되었다. 일제의 간섭이 본격화된 통감부 시기에는 '간이'와 '이용'의 교육정책에 따라 산술교육도 축소 또는 약화되었다. 이 시기에 발간된 초등교원용 산술서는 특기할 만하다.

• Earthquakes and Structures
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• 제6권2호
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• pp.201-216
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• 2014

Many building codes use the empirical equation to determine fundamental period of vibration where in effect of length, width and the stiffness of the building is not explicitly accounted for. Also the equation, estimates the fundamental period of vibration with large safety margin beyond certain height of the building. An attempt is made to arrive at the simple empirical equations for fundamental period of vibration with adequate safety margin, using soft computing technique of Genetic Programming (GP). In the present study, GP models are developed in four categories, varying the number of input parameters in each category. Input parameters are chosen to represent mass, stiffness and geometry of the buildings directly or indirectly. Total numbers of 206 buildings are analyzed out of which, data set of 142 buildings is used to develop these models. It is observed that GP models developed under B and C category yield the same equation for fundamental period of vibration along X direction as well as along Y direction whereas the equation of fundamental period of vibration along X direction and along Y direction is of the same form for category D. The equations obtained as an output of GP models clearly indicate the influence of mass, geometry and stiffness of the building over fundamental period of vibration. These equations are then compared with the equation recommended by other researcher.