• 한국폐기물자원순환학회지
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• 제34권5호
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• pp.518-527
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• 2017

The development of renewable energy is currently strongly required to address environmental problems such as global warming. In particular, biomass is highlighted due to its advantages. When using biomass as an energy source, the conversion process is essential. Fast pyrolysis, which is a thermochemical conversion method, is a known method of producing bio-oil. Therefore, various studies were conducted with fast pyrolysis. Most studies were conducted under a lab-scale process. Hence, scaling up is required for commercialization. However, it is difficult to find studies that address the process analysis, even though this is essential for developing a scaled-up plant. Hence, the present study carries out the process analysis of biomass pyrolysis. The fast pyrolysis system includes a biomass feeder, fast pyrolyzer, cyclone, condenser, and electrostatic precipitator (ESP). A two-stage, semi-global reaction mechanism was applied to simulate the fast pyrolysis reaction and a circulating fluidized bed reactor was selected as the fast pyrolyzer. All the equipment in the process was modeled based on heat and mass balance equations. In this study, process analysis was conducted with various reaction temperatures and residence times. The two-stage, semi-global reaction mechanism for circulating fluidized-bed reactor can be applied to simulate a scaled-up plant.

• 패션비즈니스
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• 제19권1호
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• pp.106-121
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• 2015

The purpose of this study is to classify the attitudes toward fast fashion into groups and analyze the differences of the self-consciousness, and make-up behavior by groups. Questionnaires are being administered from 179 high school girls living in Deagu metropolitan City. Frequency, factor analysis, reliability analysis, cluster analysis, ANOVA, Duncant-test, and ${\chi}^2$-test are all used for data analysis. Our findings are as follows. The attitude toward fast fashion shows a significant correlation with the sub-variable self-consciousness and make-up behavior. Attitude toward fast fashion is being categorized into convenience focus, fashion focus, design focus, and season focus. Self-consciousness is social self-consciousness, social anxiety, private self-consciousness, and private anxiety. Make-up behavior is positive effect, fashion leader, and conformity. Attitude toward fast fashion is classified into three groups: disposability, fashionability, and low interest of fashion. The groups show a significant difference in the self-consciousness, and make-up behavior. Groups display no distinctions between the sub-variables in the actual conditions of cosmetics such as a first time for make-up and frequence of visit.

• 대한의용생체공학회:의공학회지
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• 제15권4호
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• pp.395-400
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• 1994

ECG 신호해석을 위해서는 고해상도 스펙트럼 해석이 필수적이다. ECG 신호의 주파수 해석을 위하여 많이 사용된고 있는 FFT(Fast Fourier Transform)는 데이타 수가 적을때는 해상도가 나쁘고 Gibb의 현상을 보인다. ARMA 모델을 이용한 고해상도 스펙트럼 해석을 위하여 ARMA FTF(Fast Transversal Filter)알고리즘을 사용하였으며 ARMA FTF알고리즘의 불안정의 원인을 분석하고 이의 개선책을 제시하였다. 제안된 알고리즘을 사용하여 ECG 신호의 스펙트럼 해석에 적용하여 좋은 결과를 얻었다. 본 연구의 결과는 FFT를 사용한 결과보다 굴곡이 작아 컴퓨터를 이용한 진단에 유용하게 사용될 수 있으리라 생각된다.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2366-2372
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• 2023

Are borate and silicate glasses suitable for working as shieling materials against fast neutrons? To correctly answer the above question, some silicate, and borate-based glasses were fabricated and irradiated with various doses of fast neutrons varied between 1.73 and 12.10 MGy. The color and hardness of the fabricated glasses were affected by the fast neutron fluence where the transparent glasses turned colored as well as the hardness of the fabricated glasses was decreased. The gamma-ray spectrometric analysis shows a high activity concentration produced in the barium borate glasses due to the formation of radioisotopes Ba-131 and Ba-133 reaches to 5.92E+05 Bq and 4.25E+03 Bq, respectively for sample Cd-5 Batch 3. Additionally, the gamma-ray spectrometric analysis for the sodium silicate glasses shows low activity concentrations emitted from isotopes formed due to the activation of Y₂O₃-associated impurities. These activities are low compared to that emitted by barium borate-based glasses.

• 한국항공우주학회지
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• 제35권6호
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• pp.483-488
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• 2007

경계요소법을 이용하여 동체에 탠덤 날개를 결합한 FAST가 비평면 지면을 비행할 때의 공력 특성을 파악하였다. 본 수치해석 기법을 이용하여 계산한 결과를 실험 및 타 전산해석 결과와 비교하여 검증을 수행하였다. 날개-동체를 결합한 운송체의 공력 특성을 분석하여 안정성 확보 및 충분한 공기부상력을 가지도록 운송체 상부의 탠덤 날개를 배치하는 공력설계를 수행하였다. FAST에서 탠덤 날개가 동체의 전두부와 후두부에 위치하고, 하단 익단판을 설치하였을 때 최대 양력 성능을 얻을 수 있었다. FAST의 안정성은 탠덤날개의 플래퍼론을 이용하여 확보 가능하다.

• 한국식품영양학회지
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• 제26권2호
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• pp.301-309
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• 2013

This study was designed to provide fundamental data on the consumption of fast food for a balanced diet of university students. The effects of personal characteristics and preferences such as gender, major, residing region, living expense, school grade, dieting, physical activity, smoking and alcohol consumption on fast food consumption patterns were analyzed by surveying university students. The analysis showed significant differences (p<0.05) in the consumption of different types of fast food depending on different personal characteristics and preferences as follows : hamburger by major, physical activity and alcohol consumption; chicken by school grade, physical activity and alcohol consumption; spaghetti by gender and smoking. Groups of different majors and school grades showed significant differences (p<0.05) in response to a question "Have you ever eaten fast food for regular meals?". The choice of fast food types based on taste and price appeared to be significantly influenced by majors and gender. Different groups with different majors and dieting experience appeared to think significantly differently about fast food. In response to a question "Has the consumption of fast food changed your diet style" different groups of different majors and physical activities showed significant differences. The analysis of factors affecting fast food choices revealed that fast food is chosen significantly differently depending on gender and majors (p<0.05). The purchase of fast food appeared to be significantly affected by gender, diet, physical activity, experience of fast food and consumption of fast food for regular meals (p<0.05).

• 한국식품영양학회지
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• 제28권1호
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• pp.119-125
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• 2015

This study was analyzed to provide fundamental data on the relationship between fast food consumption behaviors and food-related lifestyle types. Data was collected from 268 middle students in the Incheon region through a self-administered questionnaire. A factor analysis extracted five comprising food-related lifestyle, which we named health seeking (factor 1), taste seeking (factor 2), easy seeking (factor 3), popularity seeking (factor 4) and safety seeking (factor 5). According to the results of the factor analysis, the food-related lifestyle showed that the average consumption was more than 2.95 and, 0.792 in Cronbach alpha coefficient. There were significant differences in the influence factor for the selection of fast food according to taste seeking and, popularity seeking types (p<0.05). Also, the easy seeking and safety seeking lifestyle types showed a significant differences for the reason the choosing criteria of fast food (p<0.05). Especially, the nutrition problem was of the highest importance for the health and safety seeking but an advertisement effect trend appealed more to the taste seeking, easy seeking and popularity seeking lifestyles. There were significant differences in fast food of intake frequency according to health seeking, easy seeking, popularity seeking and safety seeking types (p<0.05). A significant positive result of the internal characteristics of fast food consumption (p<0.05) was shown for the health seeking and safety seeking types. A significant positive result of the external characteristics of fast food consumption (p<0.05) was shown for the popularity seeking and safety seeking types.

• 복식문화연구
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• 제28권2호
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• pp.147-165
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• 2020

To identify the antecedents of repurchasing intention toward fast fashion brands, this study was conducted to examine brand authenticity and brand identification as both direct and indirect antecedents of repurchasing intention through fast fashion brand love. Through convenience sampling, 266 university students in Seoul metropolitan area completed a questionnaire survey. Data were analyzed using SPSS for exploratory factor analysis, and AMOS was used for confirmatory factor analysis and path analysis. Factor analysis revealed the following: for brand authenticity, four dimensions('originality,' 'reliability,' 'continuity,' and 'naturalness') were revealed; for both consumer brand identification and repurchase intention one dimension was revealed; and for brand love two dimensions were revealed('passion' and 'affection'). Path analysis confirmed that 'reliability' and 'naturalness'in relation to brand authenticity indirectly influenced repurchase intention through 'passion'(as a factor of brand love) and directly influenced repurchase intention. Further, 'continuity' in relation to brand authenticity indirectly influenced repurchase intention through 'affection'(as a factor of brand love) and directly influenced repurchase intention. Consumer brand identification influenced repurchase intention indirectly through two factors of brand love. These results suggest that fast fashion brand marketers should implement effective strategies that consider consumers'perceptions of brand authenticity, consumer brand identification, and brand love.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1420_1422
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• 2009

Lightning currents are one of major influences on the dynamic performance of counterpoise. High lightning current causes the dynamic grounding performance of counterpoise due to very fast fronted pulses. The previous analysis has often been based on quasi-static approximation that can not be applicable to very fast fronted pulses. To extend the analysis for fast fronted pulses in this paper, the full-wave analysis method based on the rigorous electromagnetic-field theory approach is used and the effects of the ionization of the soil are disregarded. Based on the simulation results, the empirical formulas applicable for slow and fast fronted lightning current pulses are reviewed; therefore, the validity of the theoretical approach is verified through comparison between the calculated and measured results.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.63-66
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• 2009

Lighting currents are one of major influences on the dynamic performance of ground electrodes. High lighting current intensity changes in the dynamic grounding performance due to ionization of the soil and very fast fronted pulses. The previous analysis has often been based on quasi-static approximation that is not applicable to very fast fronted pulses. To extend the analysis to fast fronted pulses in this paper, the full-wave analysis method based in the rigorous electromagnetic-field theory approach is used and the effects of the ionization of the soil me disregarded. Based on the simulation results, the empirical formulas applicable for slow and very fast fronted lightning current pulses me reviewed; therefore the validity of the theoretical approach is verified through comparison between the calculated and measured results.