• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.31-39
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• 2015

The synergistic solvent extraction of rare earth elements such as europium and yttrium has been investigated by the extractant with crown ether as an additive. Macrocyclic ligand as host-guest compounds form more stable complexes with metal ions which have the similar size of the cavity of crown ether. In our previous study[14] founded that the extraction used fatty acid of the various alkyl chain length. Based on the results of the previous experiment, the synergistic separation effect of two metals investigated that the hexanoic acid had was the worst extraction effect which added a crown ether such as 18-crown-6 ether, 15-crown-5 ether, and 12-crown-4 ether. In this study, the concentrations of hexanoic acid have showed the separation effect, and then the concentrations and kind of crown ether are performed for synergistic extraction at the hexanoic acid concentration of the highest separation effect. As a results, the separation rate is the highest value of 1.72 at 0.05 M hexanoic acid, and 0.002M 15-crown-5 ether is the best value in other concentrations and kind of crown ether, it is about twice of using only hexanoic acid. Moreover, the extraction species of two metals has been founded $MLR_3{\cdot}3RH$ form when added the crown ether.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.639-648
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• 2015

Some materials of fatty acids in the biodiesel affect the physical/chemical properties like density, kinematic viscosity, total acid number and oxidation stability by forming an organic fatty acid in combination with oxygen in the air. To solve the problem of the oxidative stability of biodiesel, various kinds of antioxidant has added and analyze the characteristics of the physical/chemical property changes by the addition of antioxidant. Oxidation stability increased by the increase of additives content. The TBHQ among the seven kinds of the additives showed the best performance. Also, 4 kinds of additives like propyl gallate, butyl-amine and pyrogallo has showed above 10 hr of oxidation stability at the addition of 500 ppm. In case of pyrogallo, this is not appropriate as an additive to suitable quality standards of total acid number. TBHA, DTBHQ of hydroquinone was satisfied with the quality standard of oxidation stability but the target of this research(above 10 hr) did not satisfied with oxidation stability. Propyl gallate is also a suitable at the quality standards of total acid number but it was shown not to be an appropriate to the additives due to increasing the total acid number by increasing of the content of additives at the addition of 500 ppm.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.136-147
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• 2015

As it carry out RPS(Renewable Portfolio Standards), power producers are using the power bio-fuel oil to meet their RPS quota. In this study, we test the quality characteristics of raw materials for power bio-fuel oil and the property changes of power bio-fuel oil by the kind of feedstocks. The power bio-fuel oil and feedstocks were analyzed for item of quality standard such as acid number, viscosity and metal contents. And it was analyzed for composition distribution by FT-IT and HPLC. Such as low priced palm oil series has high acid number and ash contents due to high free-fatty acid and metal contents. And by-product of biodiesel have a tendency of high viscosity. The fuel properties of power bio-fuel oil, such as viscosity, acid number and metal contents are correlated with the constituent and the mixing ratio of the feedstocks.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.320-328
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• 2014

Biodiesel has very similar physical properties (density, kinematic viscosity) and has even higher cetane number compare with conventional diesel. There are no necessity to change or modify the infra-structure & engine system. It is known that fatty acid methyl ester (FAME) is oxygen-contained components increasing the combustibility, biodegradability and reduced the exhaust harmful gas. These things made the biodiesel more popular as an alternative diesel fuel. But biodiesel's sources are controversial issues about $CO_2$ reduction effect at this time because those mainly come from edible plants such as soy, palm, rapeseed already spent lot of $CO_2$ to cultivate. Whereas micro-algae is focused because they are inedible and has rapid growth rates & high carbon-dioxide adsorption rate per area. In this study, we analyze the each FAME components using $GC{\times}GC$-TOFMS in stead of GC-FID and verify the previous total FAME contents method's applicability through the micro algal biodiesel derived from Dunaliella tertiolecta.

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.280-289
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• 2013

Various vehicles have been studied in order to protect skin ageing and sustain constantly moisturization. Recently, in relation to maintain of moisture, absorption and penetration of active materials, there has been introducing many preparing methods such as liposome, liquid crystal and multilamellar emulsion. We developed multilayer lamellar vesicle using cetearyl alcohol/ceteth-20 phosphate/dicetyl phosphate as analogy of phospholipid according to variation of shear rate and pH. These multilayer lamellar vesicles were confirmed by cross polarizing microscope. As results, morphologies of lamellar vesicle were not uniformed at low shear rate and pH. Also, stabilities for encapsulation of retinol were observed at $42^{\circ}C$ during two months. As a result, quantitative content of retinol decreased at low pH. Multilayer lamellar vesicle decreased 14% of transepidermal water loss compared with O/W emulsion. We compared multilayer lamellar sun cream to O/W sun cream using in vitro SPF test of water resistance and concluded that multilayer lamellar sun cream is similar to O/W sun cream in water resistance.

• Journal of Distribution Science
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• v.13 no.3
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• pp.93-100
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• 2015

Purpose - Since the early 1990s, it has been observed that the number and substance of studies on female leadership have been increasing. One of the reasons for this development may be concerned with the increasing number of female labor market participants as well as the greater opportunities for them to take higher positions in various organizations. In addition to this, the transition from mechanistic organizational structures that emphasize authority, control, and efficiency toward organic ones that focus on environmental adaptability, equality, and trust has also encouraged research on female leadership. The research tendency is based on the assumption that male and female leaders tend to exhibit different leadership styles according to their gender differences. Recent research has cast doubt on this assumption, by showing that the sociological gender roles of men and women are independent such that some female leaders show authoritative and control-oriented leadership, which were once considered to be male leadership styles. Research design, data, and methodology - This research attempts to carry out an empirical study on the gender-related leadership styles of female leaders and to examine their effect on group performance in the K business organization. This study also focuses on leader attributes such as trust, and it aims to discover whether these attributes should be regarded as independent or as moderating variables between leadership styles and performance. For these purposes, this study generated four hypotheses based on a review of the literature and it tested them using a survey. Female workers in the sales departments of the K Company, all of whom are women, were asked to provide answers to the presented questionnaires. This study hypothesizes that the type of gender roles played by women leaders will affect the job satisfaction and organizational commitment among the members of the sales group, and that the level of trust that is garnered by women leaders will also affect the types of gender roles that they play as well as employee job satisfaction and organizational commitment. Results - The results of this study show that both androgynous and masculine leadership styles are superior to the feminine leadership style in terms of employee job satisfaction and organizational commitment. However, contrary to our expectations, this study fails to show the superiority of the androgynous leadership style over the masculine leadership style. Moreover, there are no significant differences between these two leadership styles with regard to group performance. Conclusions - This study shows that it is important that different attributes of leaders, such as how trusted they are, be treated as moderating variables between leadership and performance rather than as independent variables. Finally, as this is the first attempt to view the role of the gender in a new perspective, the managerial implications of this study for leadership research, as well as its limitations, are presented. Suggestions for future related research are also proposed.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.94-106
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• 2016

Purpose: This study was to identify internal marketing, nursing professionalism, emotional exhaustion, personal accomplishment that influence turnover intention among hospital nurses and to predict in turnover intention. Methods: A cross-sectional sample of 270 hospital nurses from 2 university hospitals in Seoul and Chungbuk, South Korea. The data were collected from May to June, 2013 and using analyzed with t-test, ANOVA and stepwise multiple regression by using SPSS 19.0 program. Results: The mean score for nurse turnover was $3.91{\pm}0.53$, internal marketing $2.58{\pm}0.48$, nursing professionalism $3.30{\pm}0.64$, emotional exhaustion $3.23{\pm}0.64$, and personal accomplishment $3.24{\pm}0.41$. The significant factors of turnover intention were emotional exhaustion, internal marketing, nursing professionalism, work unit, nurse position, and education. And these factors explained 25.1% of the variance in turnover intention. Conclusion: The results from this study indicated a need to develop the intervention program to prevent turnover intention. These findings establish a baseline that will lead to further research.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.403-414
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• 2016

This study aims to examine the influence of job stress on the depression conducted with 360 police officers working at police station branch and police box in Chungbuk area, and they were divided into two sub-groups based on the age of 50 in order to analyze the buffering effect of organizational health in the relationship between job stress and depression. The main results of this study are as follows. First, the level of depression in the group older than 50 and younger than 50 were 3.22 and 2.90 respectively showing that in the group older than 50 were significantly higher. Second, the factors that influence the depression were shown to be similar for each group, but significantly different for their influence of each group. The factors that influence the depression in the group older than 50 were shown in the order of organizational structure, job stress, readership. The factors that influence the depression in the group younger than 50 were shown in the order of job stress, police officers ability, readership. Third, in the relationship between job stress and depression, buffering effects of organizational health were identified to be different in each group. Based on these results, several ways were suggested to prevent or ease the job stress and depression of police officers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.308-316
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• 2020

This study attempted to derive an equation for calculating the damage impact distance using CARIS so that local governments can quickly determine evacuation and notification of residents in the event of an ammonia-release accident. Ammonia is an accident-causing substance and one of 16 substances to prepare for resident evacuation. It is the most frequently occurring chemical with 58 chemical accidents from 2014~2019. The study derives an equation for calculating the damage impact distance according to the exposure time of ammonia based on AEGL, an acute exposure standard applicable to the general population, which is includes vulnerable groups such as infants, children and the elderly and designated by the EPA. The calculation formulas for each concentration and exposure time to classify the hazardous area according to AEGL-3 and the semi-dangerous area according to AEGL-2 were derived. A comparison of the relative standard deviation between the damage impact distance values of CARIS revealed that is was in the range of 0~2%. Local governments should consider the actual accident situation and apply the appropriate damage-affected distance calculation formula derived from the study to evacuate residents near the origin of the accident or use for protective measures such as indoor evacuation notification.

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.186-192
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• 1988

This study was carried out to estimate the stand form factor that is necessary to estimate stand volume by STRAND method among plotless sampling methods. The data measured for this study were based on the 380 sample plots from Larix leptolepis and 358 sample plots from Pinus koraiensis which were distributed in the region of Kyeongi, Kangweon, Chungbuk, Chungnam, Chun-buk and Kyeongbuk. 1. Stand form factor was highly correlated with in the following order, stand form height, stand average height, average diameter, stand age, distance of stem, and basal area height. 2. The best fitted equation of stand form factor of above two tree species were presented in table 3. 3. Stand form factor tables using estimated equations on the table 3 were prepared and presented in table 4, 5(Larix leptolepis), 6, 7(Pinus karaiensis). 4. The relatioinships between estimated value and actual value were Y=bx, where b approached nearly 1.0, and there were not any significant differences between them. 5. The percentages of estimated error on stand form factor table were ranged from 2.39% to 4.15% in Larix leptolepis and from 1.73% to 2.50% in Pinus koraiensis. Therefore, the stand form factor could be exactly estimated by use of these tables.