• The Journal of Korean Academy of Prosthodontics
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• v.57 no.2
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• pp.127-133
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• 2019

Purpose: The purpose of present study was to investigate fracture strength and mode of failure of endodontically treated teeth restored with metal cast post-core system, prefabricated fiber post system, and newly introduced polyetherketoneketone (PEKK) post-core system. Materials and methods: A total of 21 mandibular premolar were randomly grouped into 3 groups of 7 each according to the post material. Group A was for metal cast post core; Group B for prefabricated glass fiber post and resin core; and Group C for milled PEKK post cores. All specimens were restored with metal crown. The fracture strength of each specimen was measured by applying a static load of 135-degree to the tooth at 2 mm/min crosshead speed using a universal testing machine. After the fracture strength measurement, the mode of failure was observed. The results were analyzed using Kruscal-Wallis test and post hoc Mann-Whitney U test at confidence interval ${\alpha}=.05$. Results: Fracture resistance of PEKK post core was lower than those of cast metal post and fiber reinforced post with composite resin core. In the aspect of fracture mode most of the root fracture occurred in the metal post core, whereas the post detachment occurred mainly in the fiber reinforced post. In the case of PEKK post core, teeth and post were fractured together. Conclusion: It is necessary to select appropriate materials of post for extensively damaged teeth restoration and clinical application of the PEKK post seems to require more research on improvement of strength.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.406-414
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• 2018

This study was conducted to develop environmental risk assessments and biosafety guides for insect-resistant genetically modified rice in an LMO (Living Modified Organism) isolation field. In the LMO quarantine area of Kyungpook National University, the species diversities and population densities of non-target insects found on insect-resistant genetically modified rice (Bt-T), rice resistant to Cnaphalocrocis medinalis, and non-GM rice (Dongjin-byeo and Ilmi-byeo) were investigated. The Bt-T plants were, therefore, evaluated under field conditions to detect possible impacts on above ground insects and spiders. In 2016 and 2017, the study compared transgenic rice and two non-GM reference rice, namely Dongjin-byeo and Ilmi-byeo, at Gunwi. A total of 9,552 individuals from 51 families and 11 orders were collected from the LMO isolation field. From the three types of rice fields, a total of 3,042; 3,212; and 3,297 individuals from the Bt-T, Dongjin-byeo, and Ilmi-byeo were collected, respectively. There was no difference between the population densities of the non-target insect pests, natural enemies, and other insects on the Bt-T compared to non-GM rice. The data on insect species population densities were subjected to principal component analysis (PCA) without distinguishing between the three varieties, namely GM, non-GM, and reference cultivar, in all cultivation years. However, the PCA clearly separated the samples based on the cultivation years. These results suggest that insect species diversities and population densities during plant cultivation are determined by environmental factors (growing condition and seasons) rather than by genetic factors.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.403-410
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• 2021

The aim of this study was to investigate the growth characteristic and ginsenoside contents of 7 and 13 year-old wild-simulated ginseng (Panax ginseng C.A. Meyer) according to rusty root. The root growth characteristics of wild-simulated ginseng were did not shows significant difference according to the rusty root. The results of ginsenoside contents of wild-simulated ginseng according to rusty root, ginsenoside Rb1 and Rg1 of 7 year-old wild-simulated ginseng were had shows a significantly higher in rusty root compare to general root. On the other hand, ginsenodie Rc, Rd, Re and Rg2 were significantly higher in gerneral root. In the case of 13 year-old wild-simulated ginseng, the contents of ginsenoside did not shows to significant difference according to rusty root. The results of correlation analysis between growth characteristics and ginsenoside content of general root, the ginsenoside Rb2, Rc, Rd, Rf, Rg1 were positive correlation with root length, while as the ginsenoside Rd of rusty root was shows significantly negative correlation with root length. The results of this study was might be able to improve awareness of consumer related to rusty root of wild-simulated ginseng. Moreover, might be help to provide useful information on the establish quality standard and distribution system of wild-simulated ginseng.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.2
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• pp.51-78
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• 2021

Followed by 'start-up', the theme of 'scale-up' has been considered as an important agenda in both corporate and policy spheres. In particular, although it is a term commonly used in industry and policy fields, even a conceptual definition has not been achieved from the academic perspective. "Corporate Growth" in the academic aspect and "Business Growth" in the practical management field have different understandings (Achtenhagen et al., 2010). Previous research on corporate growth has not departed from Penrose(1959)'s "Firm as a bundle of resources" and "the role of managers". Based on the theory and background of economics, existing research has mainly examined factors that contribute to firms' growth and their growth patterns. Comparatively, we lack knowledge on the firms' growth with a focus on 'annual revenue growth rate'. In the early stage of the firms, they tend to exhibit a high growth rate as it started with a lower level of annual revenue. However, when the firms reach annual revenue of more than 100 billion KRW, a threshold to be classified as a 'middle-standing enterprise' by Korean standards, they are unlikely to reach a high level of revenue growth rate. In our study, we used our sample of 333 companies (6.7% out of 5,000 'fastest-growing' companies) which reached 15% of the compound annual growth rate in the last three years with more than USD 100 million. It shows that sustaining 'high-growth' above a certain firm size is difficult. The study focuses on firms with annual revenue of more than $100 billion (approximately 120 billion KRW) from the 'Inc. 2020 fast-growing companies 5,000' list. The companies have been categorized into 1) Fast-growing companies (revenue CAGR 15%~40% between 2016 and 2019), 2) Hyper-growing companies (40%~99.9%), and 3) Super-growing (100% or more) with in-depth analysis of each group's characteristics. Also, the relationship between the revenue growth rate, individual company's strategy choice (market orientation, generic strategy, growth strategy, pioneer strategy), industry/market environment, and firm age is investigated with a quantitative approach. Through conducting the study, it aims to provide a reference to the 'Hyper-Growing Model' that combines the paths and factors of growth strategies. For policymakers, our study intends to provide a reference to which factors or environmental variables should be considered for 'optimal effective combinations' to promote firms' growth.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.486-498
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• 2019

This study was conducted to investigate the leaf growth and flowering characteristics of 85 Hosta cultivars. The 85 cultivars were grown in a pot in Useful Plant Resources Center in Yangpyeong, Korea. H. 'Abiqua Blue Crinkles', H. 'Abiqua Drinking Gourd', H. 'Dancing in the Rain', H. 'Elegance', H. 'Inniswood', and H. 'Venus' were classified as a large size group (> 50 cm), while 27 cultivars including H. 'Abby', H. 'Birchwood Parky's Gold', H. 'Blue Cadet', and H. 'Blue Edge' were classified as a small size group (< 20 cm). The others were classified as a medium size groups. 79% of Hosta cultivars had leaf variegation. Leaf variegation type was divided into 5 types (standard, marginata, mediovarigata, albomaculata, striata). Among them 31 cultivars including H. 'Abby', H. 'Abiqua Moonbeam', and H. 'Atlantis' has a variegation type of marginata in the leaf. 36 cultivars including H. 'Abby', H. 'Abiqua Drinking Gourd', and H.'Abiqua Moonbeam' bloomed in late May and 9 cultivars including H. 'Black Hills', H. 'Boeun', and H. 'Fragrant Bouquet' started to flower on late August. Most flowers were below 3.0 cm in length, while H. 'Avocado' was longest on 10.0 cm. Most flowers have a lavender color group (63.5%), and 14 cultivars of Hosta showed white color group (16.5%). 12 cultivars including H. 'Blue Mouse Ears', H. 'Captain Kirk', and H. 'Fragrant Bouquet' had the fragrance in their flowers. H. 'Cherry Berry' and H. 'Revolution' had a colorful stalk, red and yellow, respectively.

• Science of Emotion and Sensibility
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• v.24 no.1
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• pp.105-114
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• 2021

This study determines the differences between Korean female university students and their Chinese counterparts residing in Korea by evaluating the subjective sensation and tactile preference in fabrics for casual shirts. Seven types of white causal shirt fabrics were selected as specimens from those available in spring and autumn shirt collection. The fabrics were made from various fibers (cotton 100%, polyester 100%, flax 100%, polyester 80%/cotton 20%, polyester 65%/cotton 35%, polyester 50%/cotton 45%/spandex 5%, and polyester 50%/modal 50%). Forty Korean and Chinese female university students subjectively assessed the subjective sensation of fabrics used for casual shirts. Participants were asked to observe the seven types of fabrics and complete the questionnaire. The subjective sensation to be assessed for white casual shirt fabrics was classified into the following four factors: smoothness, lightness, softness, and stretchiness. Subjective sensation factors showed partially significant differences by nationality. Korean female students evaluated cotton fabric as being light, whereas their Chinese counterparts evaluated the polyester/cotton/spandex blended fabric as light. Korean female students evaluated polyester/modal blended fabric as being stretchable. The tactile preference for fiber composition of the fabrics showed partially significant differences by nationality. Korean female students preferred cotton 80%/polyester 20% blended fabric, polyester 50%/cotton 45%/spandex 5% blended fabric, and flax 100% fabric. The subjective sensation of the fabrics had different effects on preferences by nationality. Smoothness and softness had positive effects on preferences for the fabrics of Korean students. However, smoothness, softness, and stretchiness had positive effects on the preferences of Chinese students. The subjective sensation and tactile preference for casual shirt fabrics showed a difference between Korean female students and their Chinese counterparts. Therefore, when planning casual shirt fabrics for female university students, it is necessary to reflect on these differences in subjective sensation and tactile preference.

• Journal of Nutrition and Health
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• v.54 no.3
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• pp.292-304
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• 2021

Purpose: This study investigated the association between the mothers' use of home meal replacement (HMR) in their children's meals and the diet quality of their young children. Methods: Three hundred and thirty-seven mothers with five-year-old kindergartners in Sejong city participated in the survey from June to July 2020. The questionnaire consisted of the status of HMR use in children's meals and questions for assessing the nutrition quotient for preschoolers (NQ-P). The subjects were classified into three groups according to the frequency of HMR use in children's meals: using HMR more than three times a week (high-frequency group; [HG], n = 65), one-two times a week (moderate-frequency group; [MG], n = 145), and less than once a week (low-frequency group; [LG], n = 130). Results: The mothers' mean age was 38.3 years. The average monthly cost of purchasing HMRs was highest at 200,000-300,000 won in HG, 50,000-100,000 won in MG, and less than 50,000 won in LG (p < 0.001). The consumption frequency of processed meats, fast foods, processed beverages, and sweet & fatty snacks was significantly higher in the HG group than the other groups. The mean NQ-P score was 60.5 in HG, 63.0 in MG, and 64.5 in LG, showing a significant difference (p < 0.01). In the sub-score according to the three areas, there were no significant differences in balance and environment among the three groups. In the moderation area, however, the score was 44.1 in HG, 51.3 in MG, and 57.5 in LG Group, showing a significant difference (p < 0.001). Conclusion: The increase in HMR use was related to the decreased diet quality in the overall and moderation areas of children's diet. These results support the importance of nutrition education for mothers, which aims to reduce their children's access and exposure to processed foods, such as HMR.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.379-394
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• 2021

Air pollution data in South Korea is provided on a real-time basis by Air Korea stations since 2005. Previous studies have shown the feasibility of gridding air pollution data, but they were confined to a few cities. This paper examines the creation of nationwide gridded maps for PM10 concentration using 333 Air Korea stations with variogram optimization and ordinary kriging. The accuracy of the spatial interpolation was evaluated by various sampling schemes to avoid a too dense or too sparse distribution of the validation points. Using the 114,745 matchups, a four-round blind test was conducted by extracting random validation points for every 365 days in 2019. The overall accuracy was stably high with the MAE of 5.697 ㎍/m³ and the CC of 0.947. Approximately 1,500 cases for high PM10 concentration also showed a result with the MAE of about 12 ㎍/m³ and the CC over 0.87, which means that the proposed method was effective and applicable to various situations. The gridded maps for daily PM10 concentration at the resolution of 0.05° also showed a reasonable spatial distribution, which can be used as an input variable for a gridded prediction of tomorrow's PM10 concentration.

• Journal of Korean Home Economics Education Association
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• v.33 no.1
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• pp.63-79
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• 2021

This study examined yearly trend of sugar-sweetened beverage(SSB) intake and compared nutritional status by SSB intake level in middle school students aged 12~14 years(n=2,543) using the data from 2007~2015 Korea National Health and Nutrition Examination Survey. SSB included carbonated drinks, sports drinks, and caffeinated drinks contained added sugar. Subjects were classified into three groups by SSB intake level obtained from 24-hour recall method: SSB 1(SSB intake 0 g/d), SSB 2(0 g/d < SSB intake < 50th percentile) and SSB 3(SSB intake ≥ 50th percentile). Result of daily intake of SSB was 76.1±6.2 g/d for boys and 59.5±4.7 g/d for girls and it was increased significantly for boys(p-trend 0.0004) and girls(p-trend 0.0038) by year. The most intakes were carbonated drinks followed by fruit juices and sports drinks for boys and girls. Percentage of daily intake compared to the dietary reference was increased for energy and iron while was decreased for calcium and vitamin C toward SSB 3 group. Ratio of excess intake of energy/fat was increased significantly for boys(p=0.0091) and girls(p<0.0001) toward SSB 3 group. Ratio of calcium deficiency was 86.8~94.9% for boys and girls and it was very high. Therefore, it should be emphasized to reduce SSB intake and drink plain water without added sugar, etc. and milk as a source of calcium for improving nutritional status of middle school students through dietary education and social support.

• The Journal of Korean Philosophical History
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• no.42
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• pp.133-164
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• 2014

In "Lu's Spring and Autumn", the ideas of all the schools before Qin Dynasty were compiled and the diagram of the Trinity of heaven, earth and man using the category of Yin-yang and the five elements of the universe since the ancient times was established. This can be assessed to be the blueprint for a unified empire closely connecting time and space, and objects in heaven and on earth centered around human beings. In specific, Yin-yang and the five elements of the universe were combined to categorize and schematize all things in the universe, and connect them to human affairs at the same time. Its contents convert almost all academic fields including politics, economics, society, military, astronomy, geography, medical science, education and history. Particularly, the documents popular during the age of civil wars and the ideas of Jikha scholars were synthesized and specified. Yet, it went beyond simple collection of the thoughts and documents since the ancient times in terms of contents and forms, and the method of 12 months for 1 year was selected and prescript was expanded to the various fields of politics and the society. In the Twelve principle, Yin-yang and the five elements, and the ten celestial stems and the earthly ones were combined, the contradiction from the process was solved, and the Rules of Four Seasons Thought was completed. Therefore, even though some parts of the idea of Yin-yang and the five elements in "Lu's Spring and Autumn" is found here and there from other documents, the unificative systematization of the whole has an important meaning in the history of thought. In summary, it has been proved that the Rules of Four Seasons Thought in "Lu's Spring and Autumn" was not limited to the physical unity of Yin-yang and the five elements of the universe, but qualitatively specified particularly in the aspects of agriculture from the people's side and politics from a leader's position.