• Resources Recycling
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• v.9 no.6
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• pp.36-44
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• 2000

Fly ash was composed of the unburned carbon and mineral particles. The former was able to attach on the bubbles, while the latter was not. Therefore, it was possible to separate the unburned carbon and the mineral from fly ash using the froth flotation process. This study was carried out to evaluate the separation efficiency as a function of the ny ash particle properties in the column flotation. Separation efficiency was analyzed for various size fraction of -38 fm,38~125 fm and 1125 W, and for various fly ash samples containing 7, 11, and 20 wt% unburned carbon. For the size fractions of -38 fm containing 7 wt% unburned carbon, separation efficiency was 86ft, whereas separation efficiency was found to be 74% for the size fraction of +125$\mu\textrm{m}$ containing 20 wt% unburned carbon. The results indicated that separation efficiency increased with the decrease in the particle size and the unburned carbon content of the fly ash.

• Journal of the Korean Institute of Gas
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• v.8 no.2 s.23
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• pp.15-27
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• 2004

The purpose of this paper is to improve the performance of Polymer electrolyte fuel cell(PEMFC) by studying the channel dimension of bipolar plates using commercial CFD program 'Fluent'. Simulations are done ranging from 0.5 to 3.0mm for different size in order to find the channel size which shoves the highst hydrogen consumption. The results showed that the smaller channel width, land width, channel depth, the higher hydrogen consumption in anode. When channel width is increased, the pressure drop in channel is decreased because total channel length Is decreased, and when land width is increased, the net hydrogen consumption is decreased because hydrogen is diffused under the land width. It is also found that the influence of hydrogen consumption is larger at different channel width than it at different land width. The change of hydrogen consumption with different channel depth isn't as large as it with different channel width, but channel depth has to be small as can as it does because it has influence on the volume of bipolar plates. however the hydrogen utilization among the channel sizes more than 1.0mm which can be machined in reality is the most at channel width 1.0, land width 1.0, channel depth 0.5mm and considered as optimum channel size. The fuel cell combined with 2cm${\times}$2cm diagonal or serpentine type flow field and MEA(Membrane Electrode Assembly) is tested using 100W PEMFC test station to confirm that the channel size studied in simulation. The results showed that diagonal and serpentine flow field have similarly high OCV and current density of diagonal (low field is higher($2-40mA/m^2$) than that of serpentine flow field under 0.6 voltage, but the current density of serpentine type has higher performance($5-10mA/m^2$) than that of diagonal flow field under 0.7-0.8 voltage.

• Journal of Science and Technology Studies
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• v.4 no.2 s.8
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• pp.67-101
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• 2004

Although the study of citation patterns is an important theme within the sociology of science, due to the fact that it is intimately related to the production, reproduction, and evaluation of knowledge, only sustained theoretical research outlining the differences of citation patterns between the hard and soft sciences has been conducted, and empirical studies nevertheless remain few and far between. The perspectives of institutionalism and constructivism have to attempted to explain different citation patterns between the hard and soft sciences as a contrast between 'what one says' and 'who one is'. Therefore, against this background this study examines the 'theoretical' controversy empirically by comparing the contrasting citation patterns of physics, as a representative of hard science, and sociology, as a representative of soft science. The results, in brief, are as follows: the citaton patterns in physics, as in sociology, vary according to the author's status within the hierarchical employment structure, i. e. whether s/he is a full-time lecturer or not, but diversity of citation patterns according to Ph. D. diploma area is unique to sociology. These results would suggest that the explanation of constructivism is more relevant in explaining variance according to the author's status in the employment hierarchy, but the approach of institutionalism is more appropriate to understanding variance due to Ph. D. diploma area. Furthermore, this implies the complex diversity of the citation patterns between the hard and soft sciences, pointing us to the more qualified conclusion that rather than having to choose between institutionalism and constructivism according to a mutually exclusive either/or logic, these two approaches can in fact be mutually complementary, and these approaches should also be applied piecemeal to different levels of phenomena. In conclusion, this comparative research enables us to assert the following two claims: firstly that physics, as a 'science in society', produces knowledge dependent on social context, and secondly that it also possesses a characteristic that transcends locality from the view of a sociology of knowledge.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.257-274
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• 2018

The purpose of this study was to evaluate the effect of acid-treatment conditions on the surface properties of the RBM (Resorbable Blast Media) treated titanium. Disk typed cp-titanium specimens were prepared and RBM treatments was performed with calcium phosphate ceramic powder. Acid solution was mixed using HCl, $H_2SO_4$ and deionized water with 4 different volume fraction. The RBM treated titanium was acid treated with different acid solutions at 3 different temperatures and for 3 different periods. After acid-treatments, samples were cleaned with 1 % Solujet solution for 30 min and deionized water for 30 min using ultrasonic cleanser, then dried in the electrical oven ($37^{\circ}C$). Weight of samples before and after acid-treatment were measured using electric balance. Surface roughness was estimated using a confocal laser scanning microscopy, crystal phase in the surface of sample was analyzed using X-ray diffractometer. Surface morphology and components were evaluated using Scanning Electron Microscope (SEM) with Energy Dispersive X-ray spectroscopy (EDX) and X-ray Photoemission Spectroscopy (XPS). Values of the weight changes and surface roughness were statistically analyzed using Tukey-multiple comparison test (p=0.05). Weight change after acid treatments were significantly increased with increasing the concentration of $H_2SO_4$ and temperature of acid-solution. Acid-treatment conditions (concentration of $H_2SO_4$, temperature and time) did not produce consistent effects on the surface roughness, it showed the scattered results. From XRD analysis, formation of titanium hydrides in the titanium surface were observed in all specimens treated with acid-solutions. From XPS analysis, thin titanium oxide layer in the acid-treated specimens could be evaluated. Acid solution with $90^{\circ}C$ showed the strong effect on the titanium surface, it should be treated with caution to avoid the over-etching process.

• (The)Study of the Eastern Classic
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• no.49
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• pp.325-355
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• 2012

This research aims to generalize the thoughts of military science of the intellectuals through the books on military arts and science, which were published in the early Joseon Dynasty. In the early Joseon dynasty, it was in a position to establish the foundation in the new monarch internally, and, at the same time, to overcome foreign powers on both northern and southern borders externally. Thus, the books on military arts and science should have to be published under a premise of such situations. Accordingly, the books on military arts and science of those days took account of political stability having reflected the activities not only as the founder of Joseon but also as the military officer in the late Goryeo along with the books' own purpose to found military arts and sciences. The books on military arts and science that published in the early Joseon Dynasty were written mostly based on Chinese military books and its annotations, except some descriptions of the history of war. However, the intellectuals at that time endeavored to redefine military arts and science from the perspective of Confucianism having evaluated Chinese military science books that were biased to boost Machiavellian tactics. As a result of this, the geographical distinctions between China and Korea were the start of an argument for the military arts and science. There were also disputes over the relationships between the military science and the Yin-Yang School, and between the military science and Confucian school. Organizing our country's own history of war for the first time in the early Joseon Dynasty is worth for putting a high evaluation. However, it cannot help but to point out the limits of the books that there are noticeable descriptions about the factors related to toadyism, and that there are no descriptions about the wars against Japanese raiders. The books on military arts and science in the early Joseon Dynasty put emphasis on the commander's leadership that should be good at both literary and martial arts, as well as the harmony in military-to-military relations. After all, the intellectuals in the early Joseon Dynasty had linked the military arts and science to the sages of Confucian school under a premise that scholarship is to be used in combination with martial arts. And, as the nexus between the two, they noted the items of virtue, such as humaneness and righteousness (仁義); ritual and music (禮樂); loyalty and filial piety (忠孝); three fundamental principles (三綱); five moral disciplines (五倫). It can be said that this point is the typical features of the military arts and science in the early Joseon Dynasty, which cannot be found in Chinese military classics.

• (The)Study of the Eastern Classic
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• no.48
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• pp.225-252
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• 2012

In this paper, the writer examined the procedural changes of Zhuzi(朱子)'s theory of ZhongHe(中和), and also investigated the evaluations thereof made by the later generations. In the stage of ZhongHeJiuShuo(中和舊說), Zhuzi(朱子) ignored the theory of Lidong(李?), which was traditional theory argued by DaoNam School(道南學派). He met Zhangshi(張?) of HuXiang School(湖湘學派) and followed the school's philosophy, 'XianChaShiHouHanYang(先察識後涵養)', meaning what you should do first prior to making great efforts in self-cultivation is to examine the past, when desiring to know yourself. Even though Zhuzi(朱子) had learned the method of moral cultivation from Lidong(李?), he was fascinated by such method of moral cultivation as 'XianChaShiHouHanYang(先察識後涵養)' advocated by HuXiang School(湖湘學派) through discussion with Zhangshi(張?). This tells that he only recognized the fact that there were no achievements WeiFa(未發), but only the achievements YiFa(已發). In the stage of ZhongHeXinShuo(中和新說), he realized the mistakes committed in the time of ZhongHeJiuShuo(中和舊說), and put emphasis upon the achievements in the time WeiFa(未發). Zhuzi(朱子) had explained the relationships among mind, nature, and emotional bond as by his theory, 'XinTongXingQing(心統性情)', meaning that mind controls humans' original nature. Also he followed self-cultivation of Respect, no longer believing the Huhong(胡宏)'s XianChaShiHouHanYang(先察識後涵養). Such a method of self-cultivation means that his method of moral cultivation centered on the achievements YiFa(已發), which was originated from HuXiang School(湖湘學派), had been changed into the method of moral cultivation with a focus on the achievements WeiFa(未發), which was theory argued by DaoNam School(道南學派). However, Zhuzi(朱子)'s theory of ZhongHe(中和) that had seemed perfect began to be discussed and polished again during Joseon Period through the debates between Ligu(栗谷) and Niuxi(牛溪) in the 16th century, and through the debates between Youan(尤庵) and Yuxuan(寓軒) in the 17th century, also through the HuLuoLunZheng(湖洛論爭) represented by Nantang(南塘) and Weiyan(巍巖). Since Zhuzi(朱子)'s theory of ZhongHe(中和) had some flaws, it had to put through such debates as mentioned above. Those debates were generated because imperfections were found in the theory of ZhongHe(中和) by Zhuzi(朱子).

• Journal of agriculture & life science
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• v.46 no.1
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• pp.123-131
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• 2012

This study was conducted to estimate correlation structure between Hanwoo steer growth traits - body weights at 6 month, 12 month, 18 month and 24 month of age, average daily gain, carcass traits, body size traits at 18 months of age. Hanwoo progeny test data(body weight, body size traits) collected from 2004 to 2008 on a total of 1,838 steers at Hanwoo Improvement Main Center(NACF) were analyzed. Carcass traits were used to score the 24 months of age and slaughter. Correlation analyses were performed with observed scales of the traits and with residuals considering fixed effects in generalized linear models. The correlated coefficient estimated between live weight at slaughter(24 months of age) and cold carcass weight was high at 0.92. Correlation between beef yield index values and backfat thickness was estimated to be high and negative at -0.92. Hip height and wither height was found to be highly correlated(0.89). Chest width and chest depth also was found to be highly correlated at 0.73. Rump width was highly correlated with chest depth(0.75) and chest width(0.74). Correlation between pelvic width and rump width was estimated to be 0.74. Hipbone width was shown to be highly correlated with chest depth(0.73), chest width(0.70), rump width(0.75), or pelvic width(0.75). Correlation between wither height and carcass weight was 0.48 in observed scale. Chest girth was phenotyically (residual correlation) correlated with carcass weight (0.51), the estimates of which were some higher than than with the other carcass traits. This study will be utilized for Hanwoo Steers genetic evaluation.

• Journal of Korean Classical Literature and Education
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• no.32
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• pp.159-191
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• 2016

This paper describes the procedure of recreating the classics which introduced in author's lecture on "Classics and Creation." The work and result of this paper is based on the activities in the Korean language and literature lecture which the author was leading at university A in Seoul in 2014. This paper aims to identify aspects of introspection that college students underwent during the procedure of recreating. The subjects for analysis were the works created by college students participating in the class through three presentations. In section 2, it is discussed three major issues regarding the process of recreating classics. One is "presentation of the background for the selection of the work to recreate and the way of implementation". Second is "analysis of the original works and case studies on recreated works". Third is "recreation of works and meta writing". Those activities were conducted as part of the lecture. In section 3, it is investigated that the pattern of introspection of college students. It focused on analyzing the attitudes of the students toward life based on their selection, analysis, and recreation of classic works. Moreover, their self-assessment of the recreated works was examined as well. It is noted that the attitudes and tendency of students when faced with problems if any. While the students in the class selected diverse works for recreating, this paper compared and analyzed the works and introspective aspects of two students who recreated Simcheongjeon. Therefore, aspects of creativity could be identified based on the pattern of their recreation, which participants subtly describe the relationship with their father in recreated works. In accordance with the analysis, it is required to select more works for an effective class on recreation of classic literature and investigate a more systematic and diverse methodology for doing so. However, since the class for recreation of classic literature uses the narrative of the original work, it would reduce the burden on creation. In addition, it is possible to scrutinize in-depth problems of participant's general issue in life by using classic literature as a medium for introspection. Moreover, it was identified that a public presentation of these works enabled exploring self-narration on more objective aspects and collecting feedback from others.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.5
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• pp.61-78
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• 2019

This study is about the effect of the founder's self-efficacy on the sales of the founding company by focusing on the factors that are currently emphasized in the founding education. In particular, this paper starts from the consciousness of the problem that the education that is being implemented to achieve the purpose of successful start-up among various government-based start-up support projects is failing to produce many start-up failures. Entrepreneurs cannot be assessed by objective financial data, but there is a high degree of uncertainty that should be determined based on their personal and learning abilities. In addition, many previous studies, which are likely to be successful when there is a high self-efficacy in a specific field due to the influence of factors such as personal experience or learning, will answer the direction of support for start-up companies. This study focuses on the impact of the founder's self-efficacy on the sales of the founding firms, especially the sales that are the key to the survival of the founding firms. This study has six major studies. First, to analyze whether the self-efficacy of entrepreneurs with respect to entrepreneurship affects the sales of entrepreneurs. Second, to analyze whether the self-efficacy of entrepreneurs with respect to market orientation affects the sales of entrepreneurs. Analysis of whether the founder's self-efficacy affects the sales of the founding firms. Fourth, analysis of whether the founder's self-efficiency affects the sales of the founding firms' understanding of management environment changes. An analysis of whether efficacy affects the sales of a start-up company, and sixth, an analysis of whether the founder's self-efficacy of business model building ability affects the sales of a start-up company. As a result of the empirical analysis, this study found that the self-efficacy of entrepreneurs on product differentiation capability and business model building capacity had a positive influence on the sales of entrepreneurs. The self-efficacy had a positive effect on self-efficacy, and the customer orientation had a positive effect on self-efficacy on business model building capacity. Also, it was confirmed that a path exists between the components of self-efficacy and that self-efficacy through the path has a positive effect on the sales of the start-up company. Therefore, the results of this study suggest the implications of establishing such a path and strengthening self-efficacy to create the survival and start-up performance of a start-up company if the goal of the start-up company is to survive when implementing various support projects for the start-up company.

• Journal of Korea Port Economic Association
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• v.25 no.3
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• pp.139-164
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• 2009

The purpose of this paper is to investigate the value chain efficiency of Korean port investment by using the newly developed multi-year and multi-stage value chain efficiency model of DEA(Data Envelopment Analysis). Inputs[port investment amount, cargo handling capacity, and berthing capacity], and outputs[cargo handling amount, number of ship calls, revenue, and score of customer service satisfaction] are used during 14 years(1994-2007) for 20 Korean seaports by using two kinds of DEA models. Empirical main results are as follows: First, Model 1 shows that the ranking order of multi-stage value chain efficiency is Stage 2, Stage 3-1, Stage 1, and Stage 3-2. And according to the value chain average efficiency scores, ranking order is stages 2, 1, 3-1, and 3-2. In Model 2, 3(Incheon, Mogpo, and Jeju) out of 9 ports show the ranking order of Stages 2, 3-2, 3-1, and 1. And value chain average efficiency scores rank in order of Stages 2, 3-2, 3-1, and 1. Second, the difference among the value chain efficiency scores of each stage comes from the efficiency deterioration of all ports except Stages 2 and 1 in Model 1. In Model 2, value chain efficiency scores among the Stages 3-1, 3-2 compared to Stage 1 were deteriorated. The main policy implication based on the findings of this study is that the manager of port investment and management of Ministry of Land, Transport and Maritime Affairs in Korea should introduce the multi-year, multi-stage value chain efficiency method for deciding the port investment amount and evaluating the effect of port investment after considering the empirical results of this paper carefully.