• 한국대기환경학회지
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• 제28권5호
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• pp.527-537
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• 2012

The increasing consumption of pseudo-petroleum products (PPP) has been disturbing the national petroleum market. The use of PPP lead to tax evasion, disturbance of sound trading principles, component corrosion of cars, and explosion accident. Also, PPP have emitted hazardous air pollutants (HAP) including the carcinogenic aromatic hydrocarbons, PAHs and aldehydes more than regular-petroleum products. It thus has potentials to cause many environmental and health care problems. In this study, benzene, toluene and xylene emissions from road transport vehicles due to the use of pseudo-gasoline are estimated for the year 2008. The results of our study provide emission estimates of benzene, toluene and xylene for the year as 405, 1,711, 717 tonne/yr, respectively for regular-gasoline. BTX emissions are calculated as 452~515, 1,882~2,264 and 732~752 tonne/yr when the amount of pseudo-gasoline is estimated to account for 6~13% for regular-gasoline consumption. BTX emissions increased as much as 12~27, 10~32, 2~5% by using pseudo-gasoline. It is found that the pseudo-gasoline should be the key component to produce HAP in urban area.

• 한국염색가공학회지
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• 제16권4호
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• pp.1-9
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• 2004

In recent, development of nano fiber has been one of the most active subjects in the world. Nano fiber is defined as a ultra fine yarn with a diameter unit of $10-100\times10^{-9}meter$, which is possible to be produced by an electro-spinning technology. In this study, physical characteristics and dyeing properties of nylon 66 nano fiber were investigated. Nylon 66 nano fiber was dyed with levelling type acid dyes. X-ray diffraction method and DSC analysis were used for the measurement of the degree of crystallization. Analysis of amino end groups was also performed in order to examine a relationship between number of amino groups and its dyeing property as well as water absorption behavior. The maximum exhaustion % of dyes and dyeing rate under various dyeing conditions, such as dyeing temperature and pH in dye bath, along with build-up properties for 2 acid dyes were evaluated. It was found that the degree of crystallization of nano fiber was smaller than that of regular fiber, and amino end groups of nano fiber were less than regular fiber. Half dyeing time of nano fiber was shorter than regular fiber because of the bigger specific surface area. Effect of pH on exhaustion % was small in case of nano fiber. Exhaustion of nano fiber increased with higher concentration of dye.

• 한국염색가공학회지
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• 제22권4호
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• pp.325-331
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• 2010

The alkaline dissolution behavior of sea-island type ultrafine nylon fiber were dependent on the concentration of NaOH and treatment time, and the most appropriate condition for alkaline dissolution was to treat with 20g/l NaOH for 30 min at $80^{\circ}C$. The dyeing properties of sea-island type ultrafine nylon fiber and regular nylon fiber were examined with 3 different types of acid dyes in this study. The dye uptakes of ultrafine nylon fiber were higher than regular nylon fiber because of large surface area per unit mass, which increased as the dye bath pH decreased. The dyeing rates on ultrafine nylon fiber were faster and dye exhaustions were higher than regular nylon fiber, however color strength and rating of wash fastness were lower. It was also found that levelling type acid dye showed fast dyeing rate on both nylon fibers than metal-complex and milling type acid dyes.

• 대한의용생체공학회:의공학회지
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• 제31권2호
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• pp.151-161
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• 2010

Soft Golf is a newly developed recreational sport in our research team aimed to become a safe and easy-to-learn sport for all ages. The advantage of Soft Golf stems from lighter weight of the club and much larger area of the sweet spot. The purpose of this study is to analyze ground reaction force(GRF) and joint angle during soft Golf club and regular golf club swing. The GRF of golf swing was recorded by 3-D motion analysis system and forceplate. The joint angle of golf swing was obtained from computer simulation model. The GRF and joint angle of golf swing are used to analysis of golf swing pattern. The pattern of GRF and joint angle during soft golf club swing was similar to that during regular golf club swing. This result means that soft golf club reduces the risk of injury and has an effect on similar entertainment of regular golf.

• 한국치위생학회지
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• 제16권6호
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• pp.1105-1114
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• 2016

Objectives: The purpose of this study was to examine the scaling experience and related factors of people diagnosed with rheumatoid arthritis. Methods: The subjects were 30,680 people diagnosed with rheumatoid arthritis from the 2014 community health survey who were $${\geq_-}19$$ years old. Data were analyzed by chi-square test and multiple logistic regression analysis. Results: Those having regular scaling included well educated people, drinkers, more than three times tooth brushing practice, and regular dental checkup. The respondents were in the higher quartile of income And the respondents who were in the higher quartile of income were less likely to have scaling experience (p<0.05). Conclusions: The scaling experience was closely related with the age, educational level, residential area, income, drinking, tooth brushing practice, and regular dental checkup. It is necessary to investigate the influencing factors of rheumatoid arthritis and periodontal diseases in the further studies.

• 한국식생활문화학회지
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• 제30권4호
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• pp.447-456
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• 2015

The purposes of this study were to determine health consciousness and eating habits of dining business owners from Seongnam city. To figure out their health levels, this study focused on quality of sleep, current state of health, health care, smoking, drinking, regular exercise, working hours, dietary behavior pattern, dietary habits, and food intakes patterns. Out of 200 subjects, 104 (52.0%) were males and 96 (48.0%) were females. Their average age was 46.60. For education level, a majority of males graduated from college, whereas a majority of females graduated from high school. Average combined ratios of overweight and obese were 62.5% for males and 25% for females. A majority worked less than 3 years in the dining business area, but 37% of subjects worked more than 10 years. Average health level was favorable, but 38.9% of subjects had hypertension. Males' percentages for smoking and drinking were higher than those of females. Regular physical activity was high, but regular exercise rate was low. Males' average eating speed was faster than that of females and had low scores for desirable eating habits. The study shows that local business owners need to take care of their health.

• 한국조리학회지
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• 제14권3호
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• pp.178-195
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• 2008

This examination was conducted as follows; 189 copies were coated in total, and demonstratively analyzed by SPSS WIN 15.0 program. The methods used in data for this analysis are as follows; Sensitivity, Reliability, Frequency, Internal consistency, One way ANOVA(Scheffe's examination) Analysis, T-test, etc. The findings of this study are as follows; firstly, it was revealed that respondents who were regular customers of Italian restaurants regarded convenient transportation, property of space, property of pastoral, visibility, and accessibility as importance. This means that Italian restaurant marketers should consider some of factors of location for business with a good view, good parking lot, location at main street, smooth flow of traffic, luxury, atmosphere of freedom, clean area around restaurants, elegant interior of the building, comfortable, luxurious, and deluxe atmosphere, and so on. Secondly, it was revealed that respondents who were regular customers of buffet restaurant either considered the same factors as the Italian restaurants above or regarded those factors less important. This suggests that restaurants should be located on main streets, on trunk roads, and in large-scale residential districts of apartment complex. Thirdly, it was revealed that respondents who were regular customers of traditional restaurants did not consider the locational factors above. This shows that traditional restaurants should be located in nearby customers' houses or their working places, and that marketers should consider focusing on their restaurants' homelike atmosphere, cleanliness, food flavors, and so on.

• 한국해양공학회지
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• 제36권5호
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• pp.303-312
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• 2022

A submarine is optimized to operate below the water surface because it spends most of its time in a submerged condition. However, the performance in free surface conditions is also important because it is unavoidable for port departure and arrival. Generally, potential flow theory is used for seakeeping analysis of a surface ship and is known for excellent numerical accuracy. In the case of a submarine, the accuracy of potential theory is high underwater but is low in free surface conditions because of the nonlinearity near the free surface area. In this study, the seakeeping performance of a Canadian Victoria Class submarine in regular waves was investigated to improve the numerical accuracy in free surface conditions by using computational fluid dynamics (CFD). The results were compared to those of model tests. In addition, the potential theory software Hydrostar developed by Bureau Veritas was also used for seakeeping performance to compare with CFD results. From the calculation results, it was found that the seakeeping analysis by using CFD gives good results compared with those of potential theory. In conclusion, seakeeping analysis based on CFD can be a good solution for estimating the seakeeping performance of submarines in free surface conditions.

• 한국음향학회지
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• 제29권7호
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• pp.422-430
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• 2010

Tonpilz 트랜스듀서의 방사 패턴은 구조 변수들에 의해 많은 영향을 받는다. 본 연구에서는 단일 모드 Tonpilz 트랜스듀서에 대해서 동일한 유효 면적을 가지는 다양한 전면추 형상에 따른 방사 패턴을 계산하였다. 트랜스듀서의 전면추 형상은 가장 많이 사용되는 원형과 정삼각형, 정사각형, 정육각형 및 정팔각형에 대해 분석하였으며, 각 형상에 대해 방사 패턴 수식을 유도하였다. 유도한 수식을 바탕으로 전면추 형상과 크기에 따른 방사 패턴의 변화를 해석하고, 서로의 특성을 비교하였다. 계산 결과의 타당성은 유한 요소 해석을 이용하여 확인하였다.

• 한국대기환경학회지
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• 제16권5호
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• pp.539-544
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• 2000

A simple analytic model is proposed here to analyze the concentration deficit field caused by a large area of vegetated area. With non-dimensional deposition velocity chosen as small parameter, the regular perturbation method is exploited to derive the mass balance equation and the dynamic equations for the concentration deficit field, Analytic solutions to those equations are obtained in a closed form for several cases of interest, assuming that the concentration field is stationary and the plume can be nicely approximated as Gaussian for a point source. The results suggest that quite a negligible fraction (less than 1%) of the gaseous air pollutants emitted into the air is removed by the vegetated area of which width is 4 km in wind-wise direction, the typical dimension of the Restricted Development Zones around the metropolitan regions in South Korea.