• Nuclear Engineering and Technology
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• v.26 no.1
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• pp.126-139
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• 1994

Best-estimate thermal-hydraulic codes, CATHARE2 V1.2 and RELAP5/MOD3, hate been assessed against the BETHSY 6.2 tc six-inch cold leg break loss-of-coolant accident (LOCA) test. Main objective is to analyze the overall capabilities of the two codes on physical phenomena of concern during the small break LOCA i.e. two-phase critical flow, depressurization, core water level de-pression, loop seal clearing, liquid holdup, etc. The calculation results show that the too codes predict well both in the occurrences and trends of major two-phase flow phenomena observed. Especially, the CATHARE2 calculations show better agreements with the experimental data. However, the two codes, in common, show some deviations in the predictions of loop seal clearing, collapsed core water level after the loop seal clearing, and accumulator injection behaviors. The discrepancies found from the comprision with the experimental data are larger in the RELAP5 results than in the CATHARE2. To analyze the deviations of the two code predictions in detail, several sensitivity calculations have been performed. In addition to the change of two-phase discharge coefficients for the break junction, fine nodalization and some corrections of the interphase drag term are made. For CATHARE2, the change of interphase drag force improves the mass distribution in the primary side. And the prediction of SG pressure is improved by the modification of boundary conditions. For RELAP5, any single input change doesn't improve the whole result and it is found that the interphase drag model has still large uncertainties.

• Journal of the Korean Society of Costume
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• v.18
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• pp.225-245
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• 1992

The button is a part of costume. But it has the symbolism of costume in itself and reflects the sociocultural phenomena. The purpose of this study is to clarify symbolism of button of eighteenth and nineteenth century which had been most popular. This study is based on the library research. Through this paper, I reached conclusions as follows. The symbolism of button is found in various ways. First, Aesthetics is found in material, color, design and type etc. of button. Especially Indian silver button of abstract type shows well distinctive aesthetics of Indians. Second, The material and the number of button vary with one's status and show off one's privilege. I England, there was the rule, in which the symbol of the King was a silver button with a figure of lion. The livery button represents his family to the nble and shows the meaning of obedience to the servant. Third, The button on uniform varies with ranks. This is prominent in a uniform of a soldier or a policeman. Fourth Material and craft of button show one's economic position. The button gives a Very good picture of what one's life was then. Precious button with gold, silver, and other jewels is an index to one's property. Fifth, The button of political event is used for election, which shows the face and the name of runner. Besides that, there were buttons designed for the flag or the slogan for political event. Sixth, The button of social event reflects a social phase of life in war or revolution, for example, it satirizes the burning of the Bastille in the French Revolution, or the taxpayer bearing the burden. Seventh, the buttons that symbolize a historic event are made to commemorante an epochal and critical occurrence or an important person's birth, death, visit to some place, etc., Eighth, there were well-known persons, for example, a president, a king, a queen, a singer, or an artist in the buton of personality. Nineth, The button of one's company shows one's community in figures or pictures, that is, this button is used as a symbol one's community. Tenth, The button varies with the development of science and technology. It gives a very good picture of what it was and what the technological level was. Eleventh, The buttons that symmbolize on occupation most impressively are uniform buttons. Symbolic marks related with a particular occupation are carved on the buttons of compary employees' uniforms. Twelfth, Various natural phenomena are designed to appear on buttons, Some express themselves simply as they are, and others appear as a symbolic form such as environmental relationship between men and nature, four seasons, a constellation and all other natural things occurring during a year. Finally, The button of rebus is a motto expressed by a combination with objects figures, letters, words, or phrases.

• Proceedings of the KSRS Conference
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• v.1
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• pp.174-179
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• 2006

Information on the distribution characteristics of tuna resources in Kiribati EEZ waters in three zones (Zone 1: west Gilbert region, Zone 2: central Phoenix region, and Zone 3: east Line region) as well as their relationship with the ocean environment is critical for sustainable managing the migratory tuna resource and fishing practices in this region. Therefore, this study is designed to investigate the spatial and temporal distribution and concentration of bigeye (BET) and yellowfin tuna (YFT) in Kiribati EEZ waters in relation to sea surface temperature (SST) and thermocline depth so as to better understand the tuna resources management basis in Kiribati waters. The geographic and temporal distribution and concentration were first displayed. Paired t-test was utilized to compare the distribution between the two tuna species based on Catch per Unit Effort (CPUE) derived from the Korean longliners during 1996 to 2004, and also among the three zones of Kiribati EEZ waters. Environmental conditions of the three zones were then compared and correlated with the CPUE of YFT and BET. In addition, the effect of ENSO phenomena on the environmental conditions and the distribution of YFT and BET within the three zones were also examined. The BET was relatively higher in the Zone 3 whereas YFT predominate in the Zone 1 and the Zone 2 due to oceanographic differences among the three zones and the ecological habitats of the two tuna species. It was suggested that El Ni?o/Southern Oscillation (ENSO) phenomena altered the oceanographic conditions of the three zones that in turn change the distribution of the two tuna species. During El Ni?o, the warm phase of ENSO, resulted in having more BET in all the three zones and the opposite observed during La Ni?a (cold phase) replacing by having relatively higher catch rate for YFT, particularly in the Zone 2. Although the results of the study are from short periods (1996 to 2004) in considering oceanographic anomality, these environmental variations should be considered into sustainable fisheries management of tuna fisheries in Kiribati EEZ waters.

• Journal of Korea Port Economic Association
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• v.24 no.3
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• pp.147-165
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• 2008

Since 2000, e-commerce has been increased continuously in its quantity and quality. The growth of e-commerce has resulted in some diversities of distribution channels, and its characteristics of not-spot trading and limited market scale has urged the on-line market to play a role of assistance to off-line market. e-Commerce causes not only the flow of forward logistics, but also that of reverse logistics with every purchasing, which is a very critical factor to hesitate for consumers to purchase the products as well as increase the price of the products. Concern about the reverse logistics by sellers and buyers influences the level of price and purchasing activity of consumers. This study firstly is to lift the awareness of the efficient control of reverse logistics with reviewing the recent change of logistics environment and phenomena of reverse logistics. Secondly we find the factors generating the reverse logistics and look into its questions, and thirdly offer not only the ways to minimize the phenomena of reverse logistics, but also a efficient control system for reverse logistics. We additionally aim to contribute to prevent the price of the products from rising and raise the customers' satisfaction through minimizing the phase of reverse logistics.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.3
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• pp.171-179
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• 2014

Sunroof buffeting is one of the most critical issues in the vehicle wind noise phenomena. The experimental approach to solve this issue typically requires a lot of time and resources. To reduce time and cost, the numerical approach could be taken, which can also privide more insights into physical phenomena involved in sunroof buffeting, only if the accuracy in its predictions are guranteed. The benchmark test of various numerical solvers is carried out for the buffeting behavior of a simplified vehicle body, the Hyundai simplified model(HSM). The results of each solver are compared to the experimental measurements in a Hyundai aeroacoustic wind tunnel(HAWT) at various wind speeds. In particular, acoustic response tests were performed and the results were provided prior to all simulations in order to consider the real world effects that could introduce discrepancies between the numerical and experimental approaches. Through this study, most solvers can demonstrate an acceptable accuracy level for actual commercial development and high precision experimental data and computational prediction priories can be shared in order to promote the numerical accuracy level of each numerical solver.

• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.245-254
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• 1995

The density of ATP-sensitive potassium($K_{APT}$) channels, that open as intracellular ATP concentration falls below a critical level, is very high in skeletal muscle surface membrane and those high density may imply that $K_{ATP}$ channels have very important physiological roles. To elucidate a role of $K_{ATP}$ in relation to fatigue, the modulating effects of potassium channel openers and blockers on the fatigue velocity(FV) of mouse extensor hallucis longus muscle(EHL) were investigated in vitro. Twitch contraction was induced by an electrical field stimulation (EFS: 24-48V, 20ms, 0.2-4Hz) and resulting contraction force was isometrically recorded. The twitch forces were gradually decreased to 25% of initial contraction force(ICF) in $37.52{\pm}1.55sec$($mean{\pm}s.e.m.$, n=135), indicating the fatigue phenomena. The mean velocity for development of the fatigue was measured during the period that twitch force decreased to half($FV_{0/0.5}$) and during the period from half to 25%($FV_{0.5/0.25}$) of ICF. The fatigue was induced once every one hour and the tissue response was stable for up to 4 hours. In control condition, ICF was $5.8{\pm}0.12g$ (n=144) and decreased to 50% of ICF with the mean fatigue velocity of $0.182{\pm}0.006g/sec$($FV_{0/0.5}$, n=135) and from 50% to 25% of ICF with $0.084{\pm}0.004g/sec$($FV_{0.5/0.25}$, n=135). Cromakalim($50{\mu}M$) significantly increased $FV_{0.5/0.25}$(n=4). Glibenclamide($IC_{50}>50{\mu}M$), $Ba^{2+}$($IC_{50}=10{\mu}M$), 4-aminopyridine($FV_{0/0.5}$, $IC_{50}=0.5mM$; $FV_{0.5/0.25}$, $IC_{50}=2mM$) decreased both $FV_{0/0.5}$ and $FV_{0.5/0.25}$ concentration-dependently up to 75%. $TEA^+$(30mM), E-4031($10{\mu}M$), tolbutamide(1mM) decreased $FV_{0.5/0.25}$, but apamin(300nM) and $TEA^+$(10mM) showed no significant effects. Our results suggest that activation of the $K_{ATP}$ channels may be major cause of $K^+$ outflux during development of the fatigue and the isolated EHL muscle could be an useful experimental preparation in studying the fatigue phenomena in skeletal muscle. In addition, the possibility of activation of delayed rectifier during the fatigue development remains to be studied further.

• Journal of The Korean Association For Science Education
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• v.31 no.5
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• pp.694-708
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• 2011

In this study, we developed tasks including cognitive scaffolding for students to explain scientific phenomena using valid evidences in science classroom and sought to investigate how tasks influence the development of small group scientific argumentation. Heterogeneous small groups in gender and achievement were organized in one classroom and the tasks were applied to the class. Students were asked to write down their own ideas, share individual ideas, and then choose the most plausible opinion in a group. One group was chosen for investigating the effect of tasks on the development of small group argumentation through the analysis of discourse transcripts of the group in 10 lessons, students' semi-structured interview, field note, and students' pre- and post argument tests. The discrepant argument examples were included in the tasks for students to refute an argument presenting evidences. Moreover, comparing opinion within the group and persuading others were included in the tasks to prompt small group argumentation. As a result, students' post-argument test grades were increased than pre-test grades, and they argued involving evidences and reasoning. The high level of arguments has appeared with high ratio of advanced utterances and lengthening of reasoning chain as lessons went on. Students had elaborate claims involving valid evidences and reasoning by reflective and critical thinking while discussing about the tasks. In addition, tasks which could have various warrants based on the data led to students' spontaneous participation. Therefore, this study has significance in understanding the context of developing small group argumentation, providing information about teaching and learning context prompting students to construct arguments in science inquiry lessons in middle school.

• The Journal of Internal Korean Medicine
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• v.32 no.1
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• pp.87-99
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• 2011

In the 18th century, Xu Lingtai (徐靈胎) and Yoshimasu Todo (吉益東洞) were medical revolutionaries. They emphasized researches about synthesis of formulae, efficacy of medication and observation and then classification of clinical phenomena, so they assumed a modern scientific character. But, there were clear differences between their academic thoughts. In this paper, we examine the causes of difference in three fields, i.e. traditional culture, viewpoints of talented people and academic personality. The first, difference was due to traditional culture. Chinese medicine has a long history and heavy traditional culture. Yin-Yang (陰陽) theory, Five Phase(五行) theory, Viscera and Bowels (臟腑) theory and Meridian and Collateral (經絡) theory stemmed from everyday practice, and Chinese people learn these theories from experience and observation. From the standpoint of Chinese people, particularly scholarly doctors [儒醫] such as Xu Lingtai, it was easy to debate medical theories. In contrast, Japanese traditional culture didn't have as long a history as China. Thus as a necessity, it was harder to disseminate traditional Chinese medicine theories in Japan. Yoshimasu Todo simplified it by cutting out the superfluous traditional Chinese medicine theory, so at that time it must have been shocking to the Japanese medical world's trends. The second, difference was due to viewpoints of talented experts. From the standpoint of Xu Lingtai, above all, medicine is just a learning, only a kind of technique, even more not a means of living. Xu Lingtai was concerned with the appearance of very talented experts such as 'great man' (偉人), and 'exceptional man' (奇士) who carried out medical research. Instead of cultivating a few talented people, Yoshimasu Todo tried to produce a large number of clinicians quickly who could treat ordinary people. The third was due to personality difference. As Xu Lingtai threw away Confucianism and studied medicine in his youth, although he had a critical attitude, he was always mild-mannered. Yoshimasu Todo always had a clearly critical and rebellious nature. Personality influenced their literary spirit and learning style, so although both advocated reactionism, the academic thought of Xu Lingtai was reformative and mild, while that of Yoshimasu Todo was revolutionary and fierce. Xu Lingtai and Yoshimasu Todo had considerably similar research domains and academic thought, so it is proper for them both to serve as examples for making a comparative study of medical history in China and Japan in 18th century.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2597-2604
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• 2012

Methylenetetrahydrofolate reductase (MTHFR) is an essential enzyme involved in folate metabolism; a single nucleotide polymorphism (SNP) C677T has been reported to be linked with altered incidences of several diseases. We here conducted a meta-analysis of 15 published epidemiological studies with a total of 7306 cases and 8062 controls to evaluate its association with prostate cancer risk with overall and subgroup analyses. No statistical relationship was found overall with any genetic model (TT vs. CC: OR = 0.80, 95%CI = [0.62, 1.04], P = 0.094; CT vs. CC: OR = 0.97, 95%CI = [0.84; 1.12], P = 0.667; Dominant: OR = 0.94, 95%CI = [0.82; 1.07], P = 0.343; Recessive: OR = 0.81, 95%CI = [0.64; 1.04], P = 0.104), but after the exclusion of several studies, we could observe the homozygote TT to confer less susceptibility to prostate cancer in carriers; moreover, different effects of the polymorphism on prostate cancer risk was detected from subgroup analysis stratified by participants' residential region: significant reduced prostate cancer risk was found to be associated with the polymorphism from Asian studies (TT vs. CC: OR = 0.47, 95%CI = [0.33; 0.67], P < 0.001; CT vs. CC: OR = 0.73, 95%CI = [0.60; 0.90], P = 0.002; Dominant: OR = 0.67, 95%CI = [0.56; 0.82], P < 0.001; Recessive: OR = 0.55, 95%CI = [0.40; 0.76], P < 0.001) while studies from Europe indicated a slight increased risk under dominant model with marginal significance (OR = 1.14, 95%CI = [0.99; 1.30], P = 0.064). Moreover, the protective effect of the polymorphism against prostate cancer was also shown by studies performed in yellow Asians (TT vs. CC: OR = 0.48, 95%CI = [0.31; 0.75], P = 0.001; CT vs. CC: OR = 0.68, 95%CI = [0.51; 0.90], P = 0.006; Dominant: OR = 0.63, 95%CI = [0.48; 0.82], P < 0.001; Recessive: OR = 0.57, 95%CI = [0.39; 0.84], P = 0.004). We propose that these phenomena should be viewed with the consideration of folate metabolism profile and different gene background as well as living habits of different populations, and more relevant studies should be conducted to confirm our hypothesis and provide a comprehensive and clear picture concerning this topic.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.11-17
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• 2014

In this study, a hydraulic model experiment under wave conditions was carried out to investigate the gap/distance between two near-unit farm lines that affects the rope kink and shape variation of a seaweed farm during mooring block movement. As a result, rope kink occurred during the low wave height condition as the gap/distance between the two near-unit farm lines decreased. The seaweed farm maintained a stable shape in the higher wave height conditions as the gap/distance between the two near-unit farm lines increased. This result indicates that rope kink is sensitively affected by the gap/distance between the two near-unit farm lines. A tendency to increase the critical wave height was observed when mooring block movement occurred, and as the mooring block weight and wave period increased. From the experimental results in which incident wave conditions and the mooring block weight changed, as the front side mooring block weight increased from 3.0 to 8.0 tons, the seaweed farm was stable, and rear side mooring block movement hardly occurred. The observed tension of the seaside mooring line was a maximum at about 3.0 ton/m.