• 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 Korean Society of Forest Science
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• v.78 no.2
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• pp.177-188
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• 1989

The habitat typing method of classification based on community has been developed on many forested areas in the ROCKY MOUNTAINS of WESTERN NORTH AMERICA, and is being used in providing an objective principle of guide for classification of forest sites, land classification, vertical distribution and multipurpose management of forest. I actually made a trial of forest habitat type classification - The methodology can be segmented into a number of tasks including reconnaissance, selection of stands to be sampled, location of plots, data gathering, preliminary and computer analysis, preparation of key- and map of habitat type and description for each habitat type in a view of forest management - on UNIVERSITY OF MONTANA FORESTS in order to examine whether its application is fit or not in korean forest circumstances : these are composed mainly of artificial forest and forest in the early stage of succession. The main results obtained from this study were summarized as follows 1. A hierarchical classification-Climax, Habitat type and Phases-of forest sites was developed using the habitat typing method of classification. 2. A diagnostic key is provided for field identification of the types based upon presence and number of indicator species, and forest managers could prepare a map of habitat type and classify forest habirat types by reference to it. 3. The classified habitat types were considered to be effective on providing an objective principle of guide for multipurpose management of forest including potential productivity for timber, feed productivity of forage and wildlife, selection of the right species in the right sites, application of method of treatment and so forth. 4. Forest habitat type classifications based upon extrapolation which used relict species and associated stands is considered to be suitable for korean forest circumstances and objective in studying potential vegetation, vertical and horizontal distribution of forest.

• Journal of dental hygiene science
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• v.9 no.2
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• pp.161-167
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• 2009

The purpose of this Study was to examine the effect of perfectionism on stress and anxiety during scaling practice in an effort to find efficient way of helping students with getting good skills. The subjects in this study were students who practiced a scaling at the oral hygiene practice lab in the Department of dental hygiene in S college from May 1 to May 31, 2008. They were divided into four groups based on their subscales of perfectionism : mixed perfectionist group, achievement striving perfectionist group, failure avoidance perfectionist group and non-perfectionist group. The measurements used were Two-Dimensional Perfectionism Scale, Stress level, Trait anxiety, State anxiety. There were no significant differences in the stress level before practice between 4 groups. There were significant differences in trait anxiety, state anxiety, total anxiety before scaling practice between 4 groups. However, these results were due to differences between mixed perfectionist group and non-perfectionist group. After practice, total anxiety was decreased from 93.71 to 89.66 and state anxiety was decreased from 45.49 to 43.38. These results were statistically significant. In order to investigate the influence of achievement striving factor and failure avoidance factor on the change of state anxiety during the scaling practice Standard Multiple Regression were employed for the statistical analysis. Failure avoidance factor was related with the increase of state anxiety during the scaling practice. So leachers have to give all effort to reduce the anxiety of students during scaling practice and provide students with motivation of achievement.

• The Journal of Korean Philosophical History
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• no.58
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• pp.97-137
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• 2018

This paper analyzes the thesis classification of the "Korean Philosophy Journal" and the subject and characteristics of two representative scholars of the Research Society in commemoration of the 30th anniversary of the establishment of the 'Korean Philosophy History Research Society'. The "Korean Philosophy Journal" was published from the 1st edition in 1991 to the 55th edition until November, 2017, and introduced a total of 582 papers. In the meantime, the 'Korean Philosophy History Research Society' became a registered place after being nominated by the Korea Research Foundation. Among the 582 chapters, 297 papers deal directly with Korean philosophy, and 174 papers on Chinese philosophy. Among the Korean philosophical theses, the most popular one was the 198th issue, and the Chinese philosophical thesis was the most popular with the subject of theology. Among the Korean philosophers, Chung Yak - Yong and Chinese philosophers Chu Shi were the most studied. Among the writers who participated in the "Korean Philosophy Journal", 203 were all of them. Among them, Lee Sang Ik published the most articles with 28, and Choi Young Sung was the second with 23. Based on Lee Sang Ik 's thesis 28, Lee Sang Ik is a well - known neo - Confucianism scholar. His research is based on the theory of neo - Confucianism and the theory of secularism. On the one hand, he establishes his own moral theories and criticizes other moral theories. On the other hand he establishes his own governing theory and criticizes other governing theories. And theoretical proposals on various problems in modern society Based on Choi Young Sung 's thesis, 23, Choi Young Sung is the best researcher in the field of studying in Korea. His research focuses on correcting mistaken perceptions and descriptions in the history of study abroad in Korea, and developing the undeveloped parts. In addition, I am looking for a new perspective on the history of studying in Korea. In addition, he has been studying the philosophical thought of Choi Chih Won in order to establish a philosophical foundation for approaching the history of thought rather than just the study of the history of thought. The "Korean Philosophy Journal" has been advanced in quantity and quality, and has developed quantitatively and qualitatively. Revitalization of the SungKyunKwan university Korean Philosophy Department is indispensable for the continuous development of "Korean Philosophy Journal" and 'Korean Philosophy History Study Society' and to create excellent scholars.

• FLOWER RESEARCH JOURNAL
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• v.17 no.4
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• pp.279-284
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• 2009

In order to recover fertility from sterile interspecific OA-1 $F_1$ hybrid (Oriental hybrid 'Mero Star' ${\times}$ Asiatic hybrid 'Connecticut King'), various concentrations (0.1, 0.3 and 0.5%) of caffeine were injected directly into flower buds and then confirmed the viability of OA-1 $F_1$ hybrid at the flowering time. After the caffeine treatment, fertilized $F_1$ hybrids were crossed as female with Asiatic hybrid 'Lanzarote' as male. Five plantlets were obtained from seven embryos of 16 pollinated flowers at 0.3% treatment of caffeine while 0.5% treatment of caffeine obtained one plant let and 0.1 % treatment of caffeine plantlet did not produce at all. Thus 0.3% of caffeine treatment was considered as optimum concentration to produce subsequent progenies and the OA-l $F_1$ hybrid treated with caffeine produced 51% of putative 2n gametes. Pollen germination of OA-2 ('Romero Star' ${\times}$ 'Lady Rosa') and OA-3 ('Expression' ${\times}$ 'Lady Rosa') was not differ between temperature treatment alone and in combination with caffeine and temperature treatment. In the reciprocal crosses of OA-1 and Asiatic hybrid 'Lanzarote' or Oriental hybrid 'Sorbonne', A ('Lanzarote') ${\times}$ OA-1 or OA-1 ${\times}$ A crosses showed better results than O ('Sorbonne') ${\times}$ OA-1 or OA-1 ${\times}$ a crosses in plant obtaining. All progenies obtained from A ${\times}$ OA-1 or OA-1 ${\times}$ A crosses were confirmed as triploids by GISH analysis.

• Korean Journal of Remote Sensing
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• v.25 no.5
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• pp.423-434
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• 2009

The Arctic environment is sensitive to change of sea-ice distribution. The increase and decrease of sea ice work to an index of globe warming progress. In order to predict the progress of hereafter earth global warming, continuous monitoring regarding a change of the sea ice area in the Arctic should be performed. The remote sensing based on an artificial satellite is most effective on the North Pole. The sea ice observation using a passive microwave sensor has been continued from 1970's. The determination of sea ice extent and ice type is one of the great successes of the passive microwave imagers. In this paper, to investigate the seasonal and inter-annual variation of sea-ice distribution we used here the sea ice data from July 2002 to May 2009 around the Arctic within $60^{\circ}N$ for the AMSR-E 12.5km sea-ice concentration, a passive microwave sensor. From an early analysis of these data, the arctic sea-ice extent has been steadily decreasing at a rate of about 3.1%, accounting for about $2{\times}10^5\;km^2$, which was calculated for the sea-ice cover reaching its minimum extent at the end of each summer. It is also revealed that this trend corresponds to a decline in the multi-year ice that is affected mainly by summer sea surface and air temperature increases. The extent of younger and thinner (first-year) ice decreased to the 2007 minimum, but rapidly recovered in 2008 and 2009 due to the dramatic loss in 2007. Seasonal variations of the sea-ice extent show significant year-to-year variation in the seasons of January-March in the Barents and Labrador seas and August-October in the region from the East Siberian and Chukchi seas to the North Pole. The spatial distribution of multi-year ice (7-year old) indicates that the perennial ice fraction has rapidly shrunk recently out of the East Siberian, Laptev, and Kara seas to the high region of the Arctic within the last seven years and the Northeast Passage could become open year-round in near future.

• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.495-505
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• 2006

In order to classify aerosol type, Aerosol Optical Thickness (AOT) and Fine mode Fraction (FF), which is the optical thickness ratio of small particles$(<1{\mu}m)$ to total particles, data from MODIS (MODerate Imaging Spectraradiometer) aerosol products were analyzed over North-East Asia during one year period of 2005. A study area was in the ocean region of $20^{\circ}N\sim50^{\circ}N$ and $110^{\circ}E\simt50^{\circ}E$. Three main atmospheric aerosols such as dust, sea-salt, and pollution can be classified by using the relationship between AOT and FF. Dust aerosol has frequently observed over the study area with relatively high aerosol loading (AOT>0.3) of large particles (FF<0.65) and its contribution to total AOT in spring was up to 24.0%. Pollution aerosol, which is originated from anthropogenic sources as well as a natural process like biomass burning, has observed in the regime of high FF (>0.65) with wide AOT variation. Average pollution AOT was $0.31{\pm}0.05$ and its contribution to total AOT was 79.8% in summer. Characteristic of sea-salt aerosol was identified with low AOT (<0.3), almost below 0.1, and slightly higher FF than dust and lower FF than pollution. Seasonal analysis results show that maximum AOT $(0.33{\pm}0.11)$ with FF $(0.66{\pm}0.21)$ in spring and minimum AOT $(0.19{\pm}0.05)$, FF $(0.60{\pm}0.14)$ in fall were observed in the study area. Spatial characteristic was that AOT increasing trend is observed as closing to the eastern part of China due to transport of aerosols from China by the prevailing westerlies.

• Korean Journal of Social Welfare Studies
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• v.47 no.1
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• pp.29-56
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• 2016

The purpose of this study is first, to explore the level of codependency among social work related professionals since codependency of professionals in the field has not been explored much in Korea. Second purpose is to examine whether codependency affects the level of burnout. Last purpose is to examine moderating effects of the Sex-role attitude on the relationship between codependency and burnout. Data were collected from the 11th of December in 2014 until the 28th of February in the following year. Self-administered questionnaires were distributed to care professionals practicing in social work institutions in Daejeon City and Choongcheong province, via email and mail. In addition, surveys were administered at several continuing education training venues. Instruments used for this study include CODAT(Codependency Assessment Tool) developed by Hughes-Hammer and colleagues in 1998, MBI(Maslach Burnout Inventory) developed by Maslach and Jackson in 1981, and SRA(Sex Role Attitude) developed by Osmond and Maryin in 1975. In total, 368 surveys were used for final analysis. The results include that gender did not have statistically significant relationship with the overall codependency, however, male showed statistically higher score than female in one of subscales of codependency called hiding oneself. Workers in the residential settings showed higher level of codependency than those in non-residential settings, especially in the subscale of Other focus or Self-neglect. Codependency showed a strong relationship with Burnout. Among the five-factor structure of the CODAT, Medical problem, Low Self-worth and Family of Origin showed strong relationship with the Burnout score. And the moderating effects of Sex-role Attitude showed a statistically significant relationship between codependency and burnout. Conservative sex-role attitude amplified the level of burnout on the relationship between codependency and burnout. Based on the result, educational and policy implications were made in order to prevent burnout among social work related professionals.

• Korea and Global Affairs
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• v.3 no.2
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• pp.5-58
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• 2019

The purpose of this article is to bring about 10.26 accident by providing a fuse for the overthrow of the Park Chung-hee administration in the 10.18 Buma uprising. So, first of all, this article has a main purpose in analyzing the comparison between Masan's 3.15 uprising and 10.18 Buma uprising. The purpose of the study is to compare the 3.15 democratic movement in Masan with the 10.18 Buma uprising, given that the incident laid the foundation for the dictator to be overthrown in the event of an anti-dictatorial movement in Masan. The research method of this article is intended to be used as a research method in the 3.15 and 10.18 protests, given that if a person in power conducts election fraud or suppresses anti-government movements in order to maintain the system, it could lead to the destruction of those in power. In the end, the Masan 3.15 uprising and 10.18 uprising failed to reach a direct attempt to overthrow the regime due to unfinished democratic movements, but with the revolution of 4.19 and the massive political transformation of 10.26 Accident, he achieved the leading role theory that allowed the Rhee Syngman and Park Chung-hee administrations. In eradicating authoritarian regimes, however, the historic significance of the democratization movement was that the authoritarian regime eventually brought about the collapse of the regime by making a hard-line stance on election schemes or popular protests over the trap of power boomerang, which causes the regime to collapse.

• Journal of Environmental Impact Assessment
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• v.28 no.5
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• pp.440-456
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• 2019

The controversy of the risk perception related to particulate matters becomes significant. Therefore, in order to understand the nature of the particulate matters, we gathered articles and comments in on-line community related to bicycling which is affected by exposure of the particulate matters. As a result, firstly, the government - led particulate matter policy was strengthened and segmented every period, butthe risk perception related to particulate matters in the bicycle community has become active and serious. Second, as a result of analyzing the perception change of outdoor activities related to particulate matters, bicycle users in community showed a tendency of outdoor activity depending on the degree of particulate matters ratherthan the weather. In addition, the level of the risk perception related to particulate matters has been moved from fears of serious threat in daily life and health, combined with the disregard of domestic particulate matter levels or mask performance. Ultimately, these risk perception related to particulate matters have led some of the bicycling that were mainly enjoyed outdoors to the indoor space. However, in comparison with outdoor bicycling enjoyed by various factors such as scenery, people, and weather, the monotonous indoor bicycling was converted into another type of indoor exercise such as fitness and yoga. In summary, it was derived from mistrust of excessive information or policy provided by the government or local governments. It is considered that environmental policy should be implemented after discussion of risk communication that can reduce the gap between public anxiety and concern so as to cope with the risk perception related to particulate matters. Therefore,this study should be provided as an academic basis for the effective communication direction when decision makers establish the policy related to particulate matters.