• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.119-130
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• 2012

To increasing efficiency of the seed production through GA₃ treatment, treatment of GA₃ 20mg/ℓ at its fourteen leaf stage had an effect on 21% increasing seed yield at leaf lettuce (cv.'Ttugseomjeokchugmyeon') in seed production from 50.9ℓ/10a to 61.7ℓ/10a, and 'GA₃ 50mg/ℓ at its eight leaf and fourteen leaf stage had a effect on 14% increasing the seed yield of head lettuce (cv.'Urake') at seed production from 14.2ℓ/10a to 21.1ℓ/10a reducing rate of dead plant in field. Especially, it will be recommended for planting after June for seed production of head lettuce owing to decreasing rate of dead by soft rot and stem rot.

• Phonetics and Speech Sciences
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• v.15 no.2
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• pp.21-29
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• 2023

This study investigates the transitional aspect of vowel harmony in Korean verbal conjugation. By observing the patterns of harmonic and disharmonic tokens of 42 verbal stems searched for in the National Institute of Korean Language (NIKL) Korean Dialogue Corpus 2020/2021, I found that disharmonic tokens appeared less than 0.1% of time, most of which consisted of an /a/-stem with a monosyllabic sentence-final suffix. It was noted that disharmonic pattern started to spread to other suffixes and possibly to /o/-stems. A simple perception test showed that the disharmonic forms might have originated from vowel reduction or undershoot. These results suggest that the ongoing change is accounted for from both the articulatory and perceptual perspectives.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.109-117
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• 2017

In the production of organic Panax ginseng, the morphological changes were confirmed by providing general water and microbubble water, respectively. Analysis of seedling ginseng treated with general water and bubbles water revealed that many seedlings were formed in the seedling treated with bubble water, and about 15% weight increase occurred in the growing period. The growth rate of stem, leaf, and root was about 15% higher than that of all. Taken together, the growth of seedling cultivation using bubble water was about 15% overall. In order to process ginseng, the dried ginseng was higher in dry weight than the general water seedling seedlings grown in bubble water. This suggests that more processed products will be produced per unit weight at the time of producing the processed products at the farm, which can directly increase the farm income.

• Journal of The Korean Association For Science Education
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• v.32 no.2
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• pp.320-330
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• 2012

Understanding the relation between basic science and applied science is important for students in understanding the importance of learning science, the relationship between scientific knowledge and human life, and for enhancing their science motivation. In this study, we evaluated the statistical validity of this hypothetical model and explored the effect of gender and students' preferred courses (e.g., humanities, science, and art) on four dependent variables. We also evaluated the differences of students' understanding across scientific domains and students' understanding concerning basic and applied scientific knowledge. Three hundred and twenty five 10th grade students participated in this survey research. Statistically, we employed bivariate correlation, partial correlation, path analysis, two-way ANOVA, and repeated measures ANOVA. Our findings illustrated that our hypothetical model was statistically valid. In addition, the significant interaction effects of gender and students' preferred courses on each dependent variable were shown. Students have different levels of understanding of the convergence of basic and applied science, the relation between scientific knowledge and human life, and the importance of learning science across scientific domains (e.g., physics, chemistry, earth science and biology).

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.2
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• pp.185-205
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• 2013

In this study, to begin with, it was discussed to gather vocabularies which are expected to be vocabularies related to four fundamental rules of arithmetic and classify them according to kinds and groups, to demarcate vocabularies related to four fundamental rules of arithmetic for using in elementary school mathematics which are associated with addition, subtraction, multiplication, and division directly. Next, the basic vocabularies related to four fundamental rules of arithmetic were discussed. At this time, regarding vocabularies related addition, subtraction, multiplication, and division as coming from the verb add, subtract, multiply, divide respectively, vocabularies that contains the stem of each verb were considered as the basic vocabularies related to four fundamental rules of arithmetics. Following it, vocabularies which assist the operation and indicate the result of the operation were included, then, vocabularies related to four fundamental rules of arithmetic for using in elementary school mathematics were demarcated and presented according to the following criteria. First, a newly coined verb or derivative using the noun form of a certain verb as a root should not be used. Second, such vocabularies of which examples do not exist or rarely exist in textbooks/workbooks should not be used, even though they are registered in mathematics glossary book published by ministry of education or Korean dictionary published by the national institute of Korean language. Third, vocabularies which are not replaceable and vocabularies which have some didactical reasons for using them should be used.

• Journal of Korean Classical Literature and Education
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• no.37
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• pp.47-73
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• 2018

This thesis aims to find out the purpose of recording . I tried to understand the reason that the compiler of included this song in the record of King Yuri. The result of tracking the intention of the compiler in this thesis is as follows. I think that was chosen as a symbol of King Yuri's character, especially connected with his inner side. By introducing a hobby that contained the inner side of King Yuri, the compiler implied that his failures and mistakes in subsequent governments stem from human limitations that did not adequately refine his qualities. I think that the compiler who showed the character of King Yuri through only one short song also showed the highest level of enjoying poetry. The enjoyment of literature is a pleasure in understanding the life of someone through literature and bring it back into their lives. In this respect, by pursuing the intend of the compiler, we will be close to the value of the song, .

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.212-220
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• 2022

When it comes to single node leafy stem cuttings of rose (Rosa hybrida), environmental management such as air temperature, relative humidity, and light affect productivity. In order to investigate the effect of air temperature and relative humidity on the cutting success rate and rooted cuttings quality, a transparent airtight box was used to implement a closed system. We have also tried to find out the most effective photoperiod and the number of leaflets in closed system using artificial light (white LED, 104.0 µmol·m^-2·s^-1 photosynthetic photon flux density). The first experiment was conducted for a total of 6 weeks under 4 airtight period conditions. The number of roots and longest root length decreased as the airtight period increased. But there were no significant differences in the survival rate, shooting rate, and rooting rate according to airtight periods. In the second experiment the results indicated that survival and shooting rate were significantly affected by the photoperiod (0/24, 2/22, 4/20, 8/16, and 16/8 h), the number of leaflets (0, 2, and 4 leaflets) of the cuttings and their interaction. The survival rate was the highest in the 16-h day length and 4 leaflets. By considering survival rate and shooting rate with energy efficiency, the 8-h day length and 2 or 4 leaflets were judged to be the most effective.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.2
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• pp.285-298
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• 2022

This study is to investigate the effects and characteristics of science and engineering integrated lessons on elementary students' creative engineering problem solving propensity (CEPSP). The science and engineering integrated lessons used in this study was a 10 lesson-hours STEM program, co-developed by University of Minnesota and Purdue University. The program was implemented in the 6th grade science class of H Elementary School located in P Metropolitan city. The main data of this study are the pre-post CEPSP result and interview with 5 students collected before and after the research. The CEPSP result was analyzed by a paired-sample t-test and hierarchical cluster analysis. As a result of the t-test, it was found that overall, the program has a positive effect on the students' CEPSP score. As a result of cluster analysis, it was confirmed that studnets' CEPSP could be classified into two groups (lower and higher score cluster). Five students whose, CEPSP score has significantly improved after the lessons were interviewed to find out what the characteristics of the program that contribute the significant change are. As a result of conducting centroid analysis of the interview transcription and the hybrid analysis method, it was found that the meaningful experiences that the five students commonly shared were 'problem solving through collaboration' and 'through repeated experiments (redesign)', problem solving' and 'utilization of scientific knowledge'. As minor reactions, 'choice of the best experimental method' and 'difference between science and engineering' appeared.

• Journal of The Korean Association For Science Education
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• v.35 no.1
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• pp.53-64
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• 2015

This research was performed of high school science classes. These science classes progressed by using Scratch, and surveyed students' perception after finishing each class. This research was conducted of male students who want to choose department of natural science in the next grade. Those classes are consisted of four classes. This study produced a journal, and contained expressions of their thinking and feeling based on experiences during attending classes and projects. Consequently, that journal was analyzed in view of understanding and perception of Scratch using science classes, and it was also included of utilizing Scratch program. Research shows following three conclusions. First, students preferred Scratch using class to general one. They attend more active with high interest, and they felt senses of accomplishment while they make output by themselves. Second, their studies passed through three stages. These are problem perception, problem solving, and producing. Problem solving stage is especially complicated and difficult stage to students. This stage is consisted of Scratch side and Science side. Scratch side has Design and applying process, and Science side has data gathering and analyzing. Students' comprehension of scientific knowledge is increased and is preserved long time through this stage. Last, students had a hard time using Scratch. Because, it is the first time to them to use that program. Therefore, we deemed that they needed to start this kind of experience at lower grade than they are now, such as middle school stage. It is expected that this type of classes are getting more expanded and more populated as a part of students' core ability.

• Journal of Life Science
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• v.29 no.6
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• pp.724-734
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• 2019

The present study investigated the cytotoxicity of particulate matter (PM) derived from car air filter (outdoor PM) and home cleaner filter (indoor PM) in the various human cell lines. Each outdoor and indoor PM were harvested by ethanol extraction method, subsequently sieved with 10 um filter paper, sterilized with autoclave and added to culture media. The half maximal inhibitory concentration ($IC_{50}$) values was significantly (p<0.05) lower in the outdoor PM, compared with indoor PM, and the significantly (p<0.05) higher $IC_{50}$ values were observed in the cancer cell lines (A-549 lung adenocarcinoma and AGS stomach adenocarcinoma), than those of normal MRC-5 fibroblasts and dental papilla tissue derived-mesenchymal stem cells (DSC). After being exposed to $100{\mu}g/ml$ outdoor PM for 7 days, the population doubling time (PDT) was significantly (p<0.05) increased in especially MRC-5 and DSC cell lines, compared with untreated cell lines. Further, the expression of senescence-associated ${\beta}$-galactosidase activity was up-regulated in all the cells exposed to outdoor PM than those of untreated control. Besides, the expression level of inflammation-associated genes, such as cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) was found to be significantly (p<0.05) increased in the outdoor PM-treated cell lines than those of untreated cell lines. Our results showed that PM induces the cytotoxicity via arrest of cell growth, cell damage and inflammation response.