• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.149-158
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• 2006

A review has been made on what kind of method can be applied to predict the dynamic derivatives of the separated PLF(Payload Fairing) halves of a launch vehicle in consideration of technology and budget. An optimal approach is selected considering the geometric characteristics of the PLF halves, the aerodynamic conditions and the required accuracy. The time history of aerodynamic force/moment coefficients are obtained for the forced harmonic motions by solving the unsteady Euler equations derived with respect to the inertial reference frame. and the dynamic derivatives are deduced by integration of the aerodynamic coefficients for one period. In this research, the dynamic derivatives are presented for 0.6$\leq$ M $\leq$2.0, $-180^{\circ}$ $\leq$$\alpha$ $\leq$$180^{\circ}$ and $-90 ^{\circ}$$\leq$$\beta$$\leq$$90 ^{\circ}$.

• Culinary science and hospitality research
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• v.15 no.1
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• pp.225-239
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• 2009

The purpose of this study is to research the relationships among LOHAS trends, healthy menu and healthful dietary behavior of university students as one of the performance variables. For this research, sample group was composed of the university students in Daegu & Gyeongbuk areas. The study required the analysis derived from a hypothesis, literature reviews and data collected. It used SPSS 14.0 from 626 university students. First, LOHAS trends was found to have positive effects on healthy menu and reusing had only positive effects on nutrition elements and nutritional value. On the other hand, durability was found not to affect nutrition elements and nutritional value significantly. Second, reusing and durability were found to have significant effects on healthful dietary behavior. Third, nutrition elements and nutritional value were found to have positive effects on healthful dietary behavior. Based on the results of this study, it is suggested that food industry managers should pay particular attention on the eating behavior of university students in developing healthy menu.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.125-136
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• 2014

The purpose of this study is to provide the bakery franchise chains with practical suggestions through the analysis of the product quality that leads to customer trust and long-term reliance. For this study, I collected corresponding materials and made an inquiry survey with special emphasis on the covariance analysis to produce trustworthy results along with the analysis of factors. For the empirical analysis, among 350 copies of questionnaire distributed in the Seoul metropolitan area, 322 copies with 96% of usable response rate were used for the analyses using SPSS 18.0 and AMOS 18.0. Then, the covariance analysis was carried out for the verification of the hypotheses of the study. A summary of the results are as follows. First, texture, color and decoration, flavor and feel showed a positive effect on customer trust. Second, customer trust had a positive effect on the long-term orientation. Third, texture, color and decoration, flavor and feel showed a positive effect on the long-term orientation.

• Clean Technology
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• v.21 no.1
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• pp.33-38
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• 2015

In this research, life cycle inventory database (LCI DB) was developed for liquid CO₂ employing life cycle assessment (LCA) methodology. As are result of characterization and normalization process, production of liquid CO₂ puts on environmental impact in the order of resource depletion, global warming, acidification, eutrophication and photochemical oxidation, and among a wide variety of input, electricity contributes in most of the impact categories. Air emission plays a key role in the acidification and eutrophication while ammonia affects most on the ozone depletion. It is anticipated that development of liquid CO₂ LCI DB makes it possible for national environmental strategies to be more activated including environmental labeling scheme.

• Korean Journal of Crystallography
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• v.6 no.2
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• pp.141-157
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• 1995

Single crystals of TeO2 with large diameter were grown by Czochralski technique with auto-diameter control system. The ratio of crystal to crucible was 60-70%. The effect of critical pulling and rotation rate on the crystal quality was studied. Optimum growth parameters for high quality crystal pulling rate was less than 1.2 mm/hr. The solid-liquid interface was convex at the rotation rate of 10-23 rpm and concave at the rotation rate of more than 25 rpm, depending on the size of crystal and crucible. The platinum concentration in the melts is one of the main factors of the constitutional supercooling and thus the bubble entrapment in the growing crystal. Growth axis was confirmed to {110} direction during the whole growth procedure. Infrared spectrometric study and dislocation density measurment by chemical etching method on the grown crystal were performed. Finally, the reasons of cooperation of striations, inclusions, and optical inhomogeneities were discussed.

• Korean Journal of Crystallography
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• v.7 no.1
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• pp.30-35
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• 1996

Calcite(CaCO3) single crystals were grown hydrothermally and transmittance of as grown crystals was measured. Instead of platinium, teflon was lined onto the wall of autoclave to prevent the corrosion of autoclave wall by acidic NH4Cl solution. Spontaneous nucleation and growth of calcite crystal on teflon was reduced considerably by addition of NaCl and /or CH3COOH and applying low temperature gradient. When the temperature gradient exceeded to a few degrees from the critical temperature gradient(6-7℃), spontaneous nucleation and growth was rapidly increased in any hydrothermal solutions. Precise temperature control is thought to be the most important factor for the growth of calcite single crystal by hydrothermal technique. As grown calcite single crytal showed high transmittance compared to natural one by UV-visible analysis.

• Management & Information Systems Review
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• v.31 no.4
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• pp.445-467
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• 2012

Service is delivered to customers through interactions between service personnel and customer that will influence encounter outcomes. During service encounter, physical, psychological, emotional elements will be put into the service delivery. Thus, the purpose of this paper was to understand the rapport in hospitality & service encounter and examine the relationship between service provider's interaction, customer's participation and relationship belief. The research findings indicated that service provider's interaction and customer's participation were positively related to rapport. Furthermore, rapport which a customer feels from employee was found to contribute greatly to successful relationship beliefs with customers.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.2
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• pp.115-121
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• 2015

The objective of this study is to present the design approach of low $CO_2$ concrete structures for reduction of $CO_2$ emissions. The design approach was implemented considering the system boundary for each processing presented in the ISO 13315-2. As for life-cycle inventory(LCI) for $CO_2$ assessment of concrete structures, data provided from domestic LCI DB was used. Based on the process presented in this study, case studies on the life-cycle $CO_2$ assessment of shear wall concrete structure was conducted. As substitution level of GGBS is 25%, the amount of $CO_2$ emissions and $CO_2$ uptake by concrete carbonation was decreased in the material, demolition and crushing, and transport phase. The amount of $CO_2$ emissions of column and total member was decreased by 26% and 22% respectively, compared to that of OPC.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.2
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• pp.195-203
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• 2018

With the explosion of SNS(social network services) users, the social commerce market has emerged as a new consumer market, and will continue to grow in recent years. Despite the market environment, however, studies are lacking as to the causes of frustration that are hurting social commerce activation. This study is based on the 'Hezbollah' 2 Factor Theory and is a study of social commerce users' satisfaction and frustration factors. For this purpose, social commerce site characteristics and user characteristics were first derived from interviews and literature reviews to confirm their relationship to satisfaction and dissatisfied products. The results showed that the price discount rate, diversity, regional infrastructure, and e-commerce familiarity resulted in the impact on the definition of satisfaction, while the price discount rate, interoperability and innovation resulted in the definition of unsatisfactory goods. It also showed that satisfaction affects the definition of intended use. In particular, the price discount rate was found to be the only factor affecting the definition of unsatisfactory as well as affecting the definition of satisfaction.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.8-8
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• 2019

전 세계적으로 ASR, ASTR과 같은 인공함양에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 수자원을 확보하고 생산수의 수질 개선을 꾀할 수 있는 지하 저수지 기술을 개발하고 낙동강 하구의 염 대수층에 설치한 시험시설에서 검증하였다. 국내외 대 하천의 하구에는 상부에는 점토층이 발달해 있고 하부에는 대수층이 대규모로 발달해 있으나 염 지하수로 포화되어 있는 경우가 많다. 점토층은 오염된 지표수나 지표면에서 발생한 오염사고로부터 하부의 피압 대수층을 분리하는 역할을 할 수 있다. 따라서 피압 대수층은 기존의 지표수 수자원 또는 대체 수자원의 한계를 극복할 수 있는 좋은 수자원 확보 공간이 될 수 있다. 지하 저수지 실증 연구를 위하여 낙동강 하구의 피압 대수층에 주입정, 양수정과 관측정 등을 포함한 시험 시설을 설치하였다. 낙동강에서 취수한 지표수의 부유물을 제거하고 대수층에 주입하여 기존의 염 지하수를 밀어내고 렌즈 형태의 담수체 (지하 저수지)를 조성하였다. 양수정과 관측정을 통하여 조사된 지하 저수지는 원 지하수가 배제되었고, 하천수보다 수질이 개선되었음을 보였다. 본 고에서는 실증 연구에서 도출된 수자원 확보 및 수질 개선 성과를 제시하고자 한다. 지하 저수지는 공사 규모가 작고, 수몰지가 발생하지 않으며, 수요지 인근에 위치해 있어 지역 내 수자원 자급이 가능하고, 토지 이용도 자유롭다. 또한 평상 시에 연중 균일한 양질의 수자원 공급이 가능하고 가뭄, 지표수 오염 등 비상 시에도 장기간 안정적으로 청정 수자원 공급이 가능하다. 지하 저수지는 물 안보도 제고를 위한 취수원 다변화 차원에서 기여할 수 있을 것으로 판단된다.