• KCID journal
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• v.18 no.1
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• pp.25-32
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• 2011

In order to effectively manage the reservoir, reservoir water quality management should be based on physicochemical and configurational characteristics. In this research, correlation between factors affecting the reservoir water quality was examined. Chl-a and COD shows the highest positive correlation. Chl-a and T-P also has a high positive correlation, however Chl-a and T-N show lower correlation relatively. Even though T-N is an important factor for phytoplankton growth which increase Chl-a concentration, corelation of Ch1-a and T-N shows that enough nitrogen in the reservoir isn't no longer limiting factor. The age of reservoir can cause of increasing COD and SS. Embankment height and elevation of reservoirs shows strong negative correlation to water quality. That means reservoir which is higher embankment height and locate in higher elevations is less contaminated. Regression expression was derived with Chl-a and water quality parameters, and height of reservoir. Finally Chl-a was simulated using regression expression and it was a good approach to predict the Chl-a concentration.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.63-64
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• 2006

In this paper, multilayer piezoelectric actuator was fabricated in order to develop ultrasonic linear motor. Multilayer actuator showed a high density of 7.78[$g/cm^3$], a large effective electromechanical coupling factor($K_{eff}$) of 0.259, a high mechanical quality factor( Qm ') of 1301, and high capacitance(c) of 19.32[nF]. Curie temperature was $343[^{\circ}C]$.

• Fashion & Textile Research Journal
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• v.18 no.5
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• pp.595-605
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• 2016

Importance of appearance as a means of self-expression and communication is increasing in modern society even for men. And appearance has become an significant factor affecting men's quality of life. The main objectives of this study were to develop an instrument measuring appearance related quality of life(ARQoL), and examine the body factors influencing ARQoL. The ARQoL instrument was developed from in-depth interviews, focus group interviews, and literature review, and were revised through two pre-tests. The final questionnaire was administered through on-line survey with 440 men. Quota sampling was used based on age and body size. The results indicated that high ARQoL group showed significantly higher satisfaction on body factors including face, weight, shape, body proportion, hair, and overall impression than low ARQoL group. There was no significant difference in terms of satisfaction on height between two groups. Factor analysis showed that ARQoL consists of four factors - physical, economic, psychological and social factors. Overall impression was the most important body factor affecting all four factors of ARQoL and has very strong influence especially on economic ARQoL. BMI was also a significant factor affecting physical, economic and social ARQoL except psychological factor of ARQoL. Face had significant influence only on economic and psychological aspects of ARQoL.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.67-70
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• 2003

This paper analyzes the causal relationship between customer satisfaction and customer loyalty in Korean High-speed Internet market, where has achieved a rapid development in these days. According to the previous literatures, profitability results from customer loyalty influenced by customer satisfaction. So, we firstly define and analyze their relationships with the survey data from 737 subscribers, by using Factor Analysis and SEM(Structural Equation Model). Secondly, we find and select major cause variables to affect customer loyalty. Finally, we suggest some useful implications to marketers on the basis of the analysis results. As a result, customer loyalty depends on the degree of customer satisfaction on network quality and service quality in high-speed Internet service. Particularly the satisfaction level on network quality affects customer loyalty relatively stronger than one on service quality. Thus it is suggested that marketers invest in improving network quality rather than service quality to enhance customer loyalty.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.3
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• pp.156-156
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• 2000

The piezoelectric properties and the doping effect for $0.95Pb(Zr_xTi_{l-x})O_3+0.O5Pb(Mn_{1/3}Nb_{2/3})O_3$compositions were studied. Also, the heat generation and the change of electromechanical characteristics, the important problem in practical usage, were investigated under high electric field driving. As a experiment results under low electric field, the value of $k_p$ and ${\varepsilon}_{33}^T$ were maximized, but $Q_m$ was minimized $(k_p=0.57, Q_m=1550)$ in the composition of x=0.51. In order to increase the values of $Q_m$, $Nb_2O_5$ was used as a dopant. As the result of that, the grain size was suppressed and the uniformity of grain was improved. Also, the values of $k_p$ decreased, and the values of $Q_m$ increased with doping concentration of $Nb_2O_5$ . As a experiment results under high electric field driving, when vibration velocity was ower than 0.6[m/s], the temperature increase was 20[℃], and the change ratio of mechanical quality factor was less than 10[%]. So, its electromechanical characteristics was very stable. Conclusively, piezoelectric ceramic composition investigated at this paper is suitable for application to high power piezoelectric devices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.332-339
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• 2020

This study was a prior study to establish the shelf life of bulletproof helmets, considered the aging factor of bulletproof helmets. To estimate the aging factor of bulletproof helmets, we established a hypothesis that the 'temperature' factor would have the greatest impact on the shelf life of the bulletproof helmet, considering the environmental treatment of the American army's bulletproof helmet's materials. To verify the hypothesis, high temperature acceleration environmental treatment of bulletproof helmets was performed, and the Arrhenius formula was applied to calculate the shelf life. The study result confirmed the negative correlation between bulletproof performance and high temperature, and the influence of temperature as an aging factor was not significant by deriving life by using the Arrhenius model. The limitation of this study is that we couldn't obtain enough samples due to the specificity (miliary supplies) of the test subjects. However, given that the life-related research on bulletproof helmets has not been carried out, this research has great implications and could be used as a reference for improving the Korean Army's bulletproof helmet specifications.

• 한국초전도학회:학술대회논문집
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• v.14
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• pp.50-50
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• 2004

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.547-548
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• 2006

In this paper, cost effective parallel-branch inductor has been proposed and developed in order to increase the quality factor of the conventional spiral inductor. This parallel-branch inductor is composed of only two metals. The presented parallel-branch inductor shows 12% improvement in the quality factor with the same area as the conventional inductor. Also, we improve the parallel-branch inductor for high frequency applications.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.490-491
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• 2008

A photovoltaic power generation system is one of the ideal clean energy sources increasingly replacing fossil fuel, which has many environmental problems such as exhausted gas or air pollution. As a photovoltaic generation system should meet the requirement to be connected to utility, power factor is an important factor for the high quality of power. This paper implements a power factor controller to improve the power quality of utility interactive photovoltaic system. To verify the effectiveness of the implemented power factor controller, the results by Electromagnetic Transients Program (EMTP) are presented.

• Journal of the Korean Dietetic Association
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• v.7 no.2
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• pp.144-152
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• 2001

This research reviews the characteristics of consumption oriented culture of post modern society and describes the food consumption culture based on the evaluative criteria pattern in eating in Ulsan Metropolitan City. The subjects consisted in 217 full-time housewives and 129 cooks. The evaluative criteria of eating scale with 4 components - the eating atmosphere factor, the preference factor, the quality factor and the table factor- is described and interpreted in the context of consumption oriented culture. 4 clusters were decided through cluster analysis; preference and quality pursuing type, high involvement type, consumerism culture pursuing type and low involvement type. Among socio-economic variables, the evaluative criteria pattern of eating was significantly associated with occupation. The results of factor analysis and cluster analysis proved that the full-time house wives and cooks in Ulsan Metropolitan city showed the propensity to consumption oriented culture in food consumption culture.