• Journal of dental hygiene science
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• v.12 no.6
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• pp.607-616
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• 2012

The purpose of this study was to examine the self-rated oral health status and oral health concern of 6,094 adults over the age of 19, which were both related to subjective oral health awareness, based on the second-year (2008) raw data of the 4th National Health and Nutrition Survey. 1. As for subjective oral health awareness, 49.4 percent replied they were in bad oral health when they were asked about self-rated oral health status. Regarding oral health concern, 62.6 percent answered they were sort of concerned about oral health. 2. As to oral health indexes by sociodemographic characteristics, there were statistically significant differences in oral health indexes according to gender, age, academic credential, monthly mean household income, frequency of eating between meals and toothbrushing frequency. Smoking made no statistically significant differences to oral health indexes (p<0.000). 3. Concerning self-rated oral health status by sociodemographic characteristics, no significant differences were found according to gender, age and academic credential, and there were statistically significant differences according to monthly mean household income and smoking (p<0.000), frequency of eating between meals (p<0.018), toothbrushing frequency (p<0.003). 4. In relation to oral health concern by sociodemographic characteristics, gender and smoking made no significant differences, and statistically significant differences were found according to age (p<0.003), academic credential, monthly mean household income, frequency of eating between meals and toothbrushing frequency (p<0.000). 5. In regard to the relationship between subjective oral health awareness and oral health indexes, none of the oral health indexes had a significant relationship to self-rated oral health status, and there were statistically significant differences in oral health concern according to functioning teeth index (p<0.011) and community periodontal index (p<0.017).

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.378-383
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• 2018

This study was carried out to investigate the optimum cultivation distance for high yielding cultivation of the new variety of Gomchwi in highland and lowland. The test material was used 'Sammany' variety and the area was cultivated with a highland of 750 m above sea level and a lowland of 20 m above sea level. The planting distance was 5 treatments of $20{\times}20cm$, $20{\times}30cm$, $30{\times}30cm$, $35{\times}40cm$ and $40{\times}40cm$, and the plant was cultivated at 35% shading net in the open field. The annual growth of 'Sammany' variety was higher in the highland than in the lowland, but the number of leaves was higher in the lowland than that in the highland. The leaf number per plant was the highest in the $40{\times}40cm$ plot and the more the planting distance was, the more tendency was. However, the leaf weight per plant was higher in the highland than in the lowland. The number of leaves per 10a were higher in the lowland than that of highland and the tendency was more as the planting distance was narrower. Yields were slightly higher in the highland than that of lowland and the highest treatment plot was 2,983 kg/10a in $20{\times}20cm$. In the second year, the growth was high in the highland, and the highland was high in the leaf number and leaf weight and the same tendency in the yields. Among the planting distances, Yields in both areas were the highest in the $20{\times}20cm$ treatment, with 3,369 kg/10a in lowland and 7,257 kg/10a in highland. The growth of the third year was slightly better in the highland than that of the lowland but the difference was not significant. However, the number of leaves and leaf weight per plant were higher in the lowland than that of highland. And, in terms of leaf number and yield per 10a, it was also higher in the lowland than that in the highland. The narrower the planting distance was increased yields, and the highest yield was 6,051 kg/10a in $20{\times}20cm$. The lowland was high in yield until the third year, but the highland was the highest in the second year and decreased slightly in the third year. The narrower the planting distance in the both areas, the higher the yield, and the leaf size tended to be small.

• Journal of Technology Innovation
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• v.29 no.3
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• pp.1-31
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• 2021

With the growing importance of technology innovation as a key factor for firms' competitive advantage, 'innovation persistence' became also an important research subject. 'Innovation Persistence' is a concept that indicates whether or not firms' innovation activity or performance continues. However, the data used for innovation studies are carried out as cross-sectional surveys in most countries. For this reason, studies dealing with longitudinal aspect of innovation persistence are rare. In particular, there is almost no research on innovation persistence using Korean innovation survey data. This study reviews the concepts and characteristics of innovation persistence based on extant literature, and perform an empirical analysis on the status and features of Korean firms' technology innovation persistence. Based on the data of the Korean Innovation Survey (KIS) conducted every other year from 2012 to 2018, panel data on 3,379 firms which observed multiple times are constructed. As a result, only part of the firms with persistent innovation were observed (for innovation performance 10~12%, for innovation activity 15~17%), and it was found that the persistence of non-innovation was remarkable(about 52~57%). And it was confirmed that the persistence of innovation activities is stronger than that of innovation performance. Besides, some features by sub-types of innovation appeared. Product innovation showed higher persistence than process innovation, and internal R&D also showed higher persistence than joint/external R&D. As a result of additional logit analysis to identify factors, it was found that radical or gradual product innovation is the most influential factor in persisting innovation in the next period. Since the sample selection bias due to a limitations of raw data might exist in the panel data constructed in this study, it should be noted that faulty generalization of the results are not allowed. Nevertheless, this is the first study to examine the technology innovation persistence targeting Korean firms and is expected to be a starting point for follow-up studies. It is anticipated that advanced research results will be drawn through the establishment of official panel data and improved methodologies.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.40-49
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• 2010

This study was conducted to examine genetic variation on leaf characteristics of Zelkova serrata populations. Leaf samples were obtained from eighteen populations and fourteen leaf characteristics such as leaf blade length, leaf width, leaf area and etc. were measured. In all leaf characteristics, there were significant differences among populations and among individuals within population. Most variance of leaf characteristics was contributed to among individuals within population except for length from leaf base to maximum width (x3) and the ratio of x3 to leaf blade length (x10). The relatively high variations of leaf characteristics were found at Gurye, Jungeup and Gyungju populations while Youngwol, Cheongsong, Youngchun populations showed the lower variation. There was high correlation among leaf characteristics related to leaf size, but not among the variables of ratio between leaf characteristics. Length from leaf base to maximum width(x3) and the ratio of x3 to x10 showed significant positive correlation with latitude and altitude of populations, which reflect the differences of mean annual temperature among populations. Mean annual rainfall of populations showed negative correlation with leaf blade length, leaf width, length from apex to first serration and leaf area. Four principal components (PC) were deduced from principal component analysis, which explain the 88.5% of total variance of leaf characteristics. Leaf area, length from leaf base to maximum width, serration number and petiole length showed the highest contribution to PC1, PC2, PC3, PC4, respectively. According to cluster analysis, the populations of Z. serrata were divided into two groups, which reflect the difference of mean annual temperature between groups. Within group, however, specific tendency of clustering was not observed among populattions.

• The Korean Journal of Archival Studies
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• no.17
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• pp.247-292
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• 2008

Investigations have been started to set the modern history and national spirit to rights after Commissions were established. Those Commissions are established and operated with time limit to finish its own missions. They creates three kinds of records as acquired materials which acquired or are donated for investigation; investigation records as investigation reports; and administrative records that created while supporting organization's operation. The Commissions use more past records to do special tasks asnation's slate clean and uncovering the truth than other agencies. In other words, the commissions take the most advantages of well-managed records, however, their record management environment and operation systems are relatively loose than other permanent machineries. It has three reasons that; first, there is no record management regulations and criteria for machineries that have time limit. This affected each commissions 'systems and 6 Truth Commissions' record management systems are built separately and on the different level; Second, members lack responsibility from frequent sending, reinstatement, change, and restructuring and that makes troubles to produce and manage records; Third, central archives pay less attention to machineries that operated limited period as the truth commissions. The Commissions rather need more systematic control because its records have historical value. To solve these problems, record management regulations have to be prepared first with features of organizations running limited time and commissions' records as acquired materials or investigation records. Furthermore, building up standard record management system for the Commissions, standardizing transfer data, imposing professional record personnel, and setting limits frequent personnel changes would finish practical problems. Besides, those records created to reveal the truth should use for education and research because Truth Commissions are established to set unfortunate history right and not to repeat it again. The records would serve as steppingstone for establishment of the Truth Record Center that does education, information work, publication, and research with the records. The record center would help using the records efficiently and improving knowledge for its people. And, the center should devote people to recognize importance of the records.

• Korean Journal of Child Education & Care
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• v.19 no.2
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• pp.177-196
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• 2019

Objective: This study aims to analyze research trends related to software education for young children, focusing on studies published in Korea from 2016 to 2019 March. Methods: A total of 26 research publications on software education for young children, searched from Korea Citation Index and Research Information Sharing Service were identified for the analysis. The trend in these publications was classified and examined respectively by publication dates, types of publications, and the fields of study. To investigate a means of research, the analysis included key topics, types of research methods, and characteristics of the study variables. Results: The results of the analysis show that the number of publications on the topic of software education for young children has increased over the three years, of which most were published as a scholarly journal article. Among the 26 research studies analyzed, 16 (61.5%) are related to the field of early childhood education or child studies. Key topics and target subjects of the most research include the curriculum development of software education for young children or the effectiveness of software education on 4- and 5-year-old children. Most of the analyzed studies are experimental research designs or in the form of literature reviews. The most frequently studied research variable is young children's cognitive characteristics. For the studies that employ educational programs, the use of a physical computing environment is prevalent, and the most frequently used robot as a programming tool is "Albert". The duration of the program implementation varies, ranging from 5 weeks to 48 weeks. In the analyzed research studies, computational thinking is conceptualized as a problem-solving skill that can be improved by software education, and assessed by individual instruments measuring sub-factors of computational thinking. Conclusion/Implications: The present study reveals that, although the number of research publications in software education for young children has increased, the overall sufficiency of the accumulated research data and a variety of research methods are still lacking. An increased interest in software education for young children and more research activities in this area are needed to develop and implement developmentally appropriate software education programs in early childhood settings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.40-47
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• 2019

This study was conducted to investigate the effect of planting density on plant growth, yield, and quality in the sweet sorghum cultivar 'Chorong' (Sorghum bicolor (L.) Moench). Plants were cultivated at densities of 16.7, 11.1, 8.3, 6.7, and $5.6plants{\cdot}m^{-2}$. Factors related to yield and yield components were analyzed using correlation and multivariate analyses. There was no significant difference among plant densities in stem length from 20 to 110 days after sowing. But the stem diameter was thin, and a decrease in number of tillers occurred more rapidly as planting density increased. At harvest, juice and sugar yield were higher at densities of 16.7 (42.9, $4.16Mg{\cdot}ha^{-1}$, respectively) and 11.1 (37.1, $3.73Mg{\cdot}ha^{-1}$) $plants{\cdot}m^{-2}$ than at 8.3 (30.5, $2.96Mg{\cdot}ha^{-1}$), 6.7 (26.6, $2.41Mg{\cdot}ha^{-1}$), and 5.6 (24.7, $2.22Mg{\cdot}ha^{-1}$) $plants{\cdot}m^{-2}$. The soluble solids and total sugar contents were not different among treatments, but relatively high values were observed at the density of 11.1 and $8.3plants{\cdot}m^{-2}$. As plant density was increased from 5.6 to $11.1plants{\cdot}m^{-2}$, the lodging index (1 = no, 9 = lodging) increased rapidly from 2.00 to 6.33. To determine the optimal planting density, the number of typhoons and topographical characteristics should be considered. Correlation and principal components analyses revealed that plant density exhibited a positive relationship with fresh stem yield ($r=0.62^{**}$), dry stem yield ($r=0.58^{**}$), juice ($r=0.63^{**}$), and sugar yield ($r=0.66^{**}$), but a negative with stem diameter ($r=-0.65^{**}$). The yield factors were not statistically related to stem height, diameter, and number of nodes.

• Korean Journal of Heritage: History & Science
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• v.49 no.4
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• pp.80-95
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• 2016

This study sought to disclose the problems surrounding the erroneous explanation of the title of the musical script 'Jeongdaeeop,' which is Jongmyojeryeak(Jongmyo Shrine ritual music), shown in Daeakhubo, Korea's treasure No.1291. Daehakhubo imitated and adopted expressions like 1 Byeon(change) and 1 Pyeon(edition), shown in the music written in the Annals of King Sejong, the foundation of Jongmyojeryeakbo music. Originally, 'Jeongdaeeop' recorded during the reign of King Sejong consisted of 6-Byeon and 13-Pyeon compositions, except Inlet and Outlet tunes. King Sejo, however, while rearranging this music into Jongmyo Shrine Mumuak music, reduced it to 9 tunes. And, when registering such arrangements in the musical scripts in the Annuals of King Sejo, he did not list the explanation of the titles as in the Annals of King Sejong. He just listed the nine tunes. In contrast to the musical scripts in the Annals of King Sejo, in Daeakhubo the details of Byeon and Pyeon under the nine tune titles are listed as in the Annals of King Sejong. This study revealed that Byeon and Pyeon expressed in Daeakhubo were the results of arbitrarily transcribing the different Byeon and Pyeon of 'Jeongdaeeop' and 'Balsang' in the Annals of King Sejong into the revised 'Jeongdaeeop' during the reign of King Sejo. Thus, under the titles of each score in 'Jeongdaeeop' of Daeakhubo are written the explanations of the muscial scores shown in both 'Jeongdaeeop' of the Annals of King Sejong and 'Balsang' of the Annals of King Sejong. Thus, the story of the son Ikjo is described even ahead of the story of the father Mokjo, and stories totally different from the original movements are described, creating overall errors. Such errors were presumably caused by powers that created the false musical script 'Sokakwonbo' during the Japanese colonial rule of Korea and disguised it as a traditional musical script.

• (The)Study of the Eastern Classic
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• no.72
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• pp.67-95
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• 2018

Gyeong-san(經山) Jeong Won-yong(鄭元容, 1783~1873) passed the state examination in 1802(純祖 2), and he has been in office for about 70 years. Jeong Won-yong with excellent administrative ability, he was an important figure in the Sedo politics, and was recognized by many writers for his outstanding writings. Nevertheless, his research results are small. This paper studyed his literary theories as a preliminary to look at Jeong Won-yong's literature in general After examining the features of Jeong Won-yong, there were three main aspects. First, Jeong Won-yong had a negative view of imitation. In particular, he stressed that he should oppose the attitude of unconditionally following Go-in(古人) without considering his capabilities and express his intention. Second, Jeong Won-yong pursued Jin-ui(眞意) when he wrote a poem. He thought rather than think that it is important to decorate a poem, it is important that emotion is exposed to the poem in a natural way. And he tried to unfold his individuality in the poem without copying others. Because if he imitate someone else when he write a poem, it is hard to express his thinking. His negative view of imitation and he pursued Jin-ui(眞意) are closely related. Lastly, Jeong Won-yong considered records important. Jeong Won-yong's record spirit is deeply related to his government service life. Jeong Won-yong who had been in government service all his life, hoped his experience would help manage the country. That's why he thought records were very important. And through this recording behavior, he wanted to get help later on. So it seems that he left a vast works.

• (The)Study of the Eastern Classic
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• no.70
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• pp.211-255
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• 2018

A classical lyrics novel 'Jeobuin-jeon' is basically old Korean novel in aspect of contents even though it has lyrics for a song formally. In other words, it shows classic poetry but also expends its genre to novel 'Jeobuin-jeon' which belongs to Jae-yeon Park's selection, presents 'Analects' at a book cover and writes its title inside. In addition, it rewrites the story of 'Jeobuin-jeon' at the beginning that means it is novel. It is considered there might be an unclear reason why it could not be marked as an novel outside. 'Jeobuin-jeon' of Jae-yeon Park's selection helps readers grasp the novel by adding Chinese characters for additional explanation based on Korean characters depending on cases. Used words in this novel is estimated being written from the late $19^{th}$ century to the beginning of the $20^{th}$ century. 'Jeobuin-jeon' is assumed being written by woman as it emphasizes that woman should learn letters and take care of the relationship among parents-in-law, husband, sibling, servant and daughter-law. Besides, this novel intends to punish bad characters through 'Jeobuin's good manners by including afterlife-story with 'Bulddong-Aemi'. 'Jeobuin-jeon''s narration is 7 steps and it reaches the peak when 'Bulddong-Aemi' and 'Jeobuin' changes their life each other. Afterward, 'Jeobuin' meets her parents-in-law and passes the crisis. The story ends through 'Bulddong-Aemi' is punished. It is very creative by developing the story with looking back the past would make a change in narration.