• Mycobiology
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• v.39 no.2
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• pp.79-84
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• 2011

Nuclear distribution within the extra-radical fungal structures and during spore production in the arbuscular mycorrhizae fungus Glomus intraradices was examined using an in vitro monoxenic culture system. A di-compartmental monoxenic culture system was modified using a nitrocellulose membrane and a coverglass slip for detailed observations. Nuclear distribution was observed using the fluorescent DNA binding probes SYBR Green I and DAPI. Both septate and non-septate mycelial regions were observed, but cytoplasmic contents were only found within non-septate mycelia. Nuclear fluorescent staining revealed that the non-septate hyphal region contained nuclei only with cytoplasm, and that nuclear distribution was limited by septa. Swollen hyphal bodies were often associated with septate and empty-looking hyphae. Cytoplasmic contents filled the swollen hyphal body from the non-septate hyphal region following removal of the septa. As a consequence, the swollen body developed into a new spore. These observations provide understanding about the distribution of AM fungal nuclei within extra-radical mycelia and during spore formation. The results suggest a mechanism by which the development of a cytoplasm-containing mycelium is controlled by the formation or removal of septa to efficiently maintain and proliferate essential contents. This mechanism may provide a survival strategy to the fungus.

• The Mathematical Education
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• v.57 no.4
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• pp.413-431
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• 2018

In this study, I developed an activity oriented lesson to support the understanding of probabilistic and quantitative estimating population ratios according to the standard statistical principles and discussed its implications in didactical respects. The developed activity lesson, as an efficient physical simulation activity by sampling with replacement, simulates unknown populations and real problem situations through completely closed 'Closed Box' in which we can not see nor take out the inside balls, and provides teaching and learning devices which highlight the representativeness of sample ratios and the sampling variability. I applied this activity lesson to the gifted students who did not learn estimating population ratios and collected the research data such as the activity sheets and recording and transcribing data of students' presenting, and analyzed them by Qualitative Content Analysis. As a result of an application, this activity lesson was effective in recognizing and reflecting on the representativeness of sample ratios and recognizing the random sampling variability. On the other hand, in order to show the sampling variability clearer, I discussed appropriately increasing the total number of the inside balls put in 'Closed Box' and the active involvement of the teachers to make students pay attention to controlling possible selection bias in sampling processes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.150-152
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• 2022

In this work, we propose a model that considers the behavior and synaptic plasticity of sensory neurons based on Liquid Time-constant Network (LTC). The neuron connection structure was experimented with four types: the increasing number of neurons, the decreasing number, the decreasing number, and the decreasing number. In this study, we experimented using a time series prediction dataset to see if the performance of the changed model improved compared to LTC. Experimental results show that the application of modeling of sensory neurons does not always bring about performance improvements, but improves performance through proper selection of learning rules depending on the type of dataset. In addition, the connective structure of neurons showed improved performance when it was less than four layers.

• Journal of Science Education
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• v.40 no.1
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• pp.31-51
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• 2016

The purpose of this study was to develop "Movie Production Project" Science-Arts convergence STEAM program for elementary students and investigate the effects of the program on career orientation of science, career awareness and creative personality. Participants were 82 elementary school students. The results of this study were as follows: First, experimental group's total score of career orientation of science was significantly higher than that of comparative group. Among sub-areas, science learning preference, science career preference and perception on science career worth were significantly different between two groups. Experimental group's scores were significantly higher than those of comparative group. Second, experimental group's career awareness total score was significantly higher than that of comparative group including all sub-areas. Third, experimental group's creative personality total score was significantly higher than that of comparative group including 2 sub-areas, independence, openness. Finally, experimental group student's perception on the program showed that it was interesting, a little easy and they hoped to study again.

• Journal of Science Education
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• v.41 no.1
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• pp.111-134
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• 2017

The purpose of this study was to develop 'Silver Care Expert' STEAM Program for the elementary students and investigate the effects of the program on creative thinking activity, scientific attitude and leadership. Participants were 110 elementary school students. Before and after the program, the participants were asked to take the test about future time perspective, career awareness and scientific attitude. The major results of this study were as follows. First, the total score of experimental group's future time perspective and all 2 sub-domains was significantly improved than those of comparative group(p<.05). Second, total score of experimental groups' career awareness and all 4 sub-domains were significantly increased than those of comparative group after the STEAM program(p<.05). Third, the total score of experimental groups' scientific attitude and all 7 sub-domains were significantly improved than those of comparative group(p<.05). Fourth, according to students' post-program opinions, experimental group students showed very positive perception like that science class was very interesting and they became interested in science and technology. In conclusion, 'Silver Care Expert' STEAM Program was very effective to improve elementary students' future time perspective, career awareness, scientific attitudes.

• Journal of The Korean Association For Science Education
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• v.40 no.2
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• pp.227-236
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• 2020

This study examines the change in students' science attitude and the growth of their core competencies through science classes emphasizing digital literacy. To this end, we conducted a study on 116 first graders in C middle school in the C region, and entered a science class that emphasized digital literacy of 35 classes. First, as a result of examining the effect on science attitude, a statistically significant change (p<.05) was observed. The effect size for each subregion ranged from 0.67 to 1.52. Second, there were no differences in the overall frequency of growth perception according to the type of class that emphasized digital literacy. However, in the analysis of core competencies, Web-based classes did not show a large difference in frequency by core competencies, whereas high-tech classes were slightly different by core competencies. This is an implication for science education, and it is necessary to increase the utilization of science classes that emphasize digital literacy.

• Journal of Elementary Mathematics Education in Korea
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• v.23 no.4
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• pp.459-479
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• 2019

The purpose of this study is to explore the research trends and knowledge structures of 『Journal of Elementary Mathematics Education in Korea』 by applying the keyword network analysis. To do this, we analyzed the frequency of the occurrence of keywords in the journal and conducted keyword network analysis using the Krkwic program and NodeXL program. The results of the analysis are as follows. Firstly, 749 keywords were extracted from keyword cleansing process and 48 keywords, including mathematics curriculum, mathematics textbooks, school mathematics, mathematical problem solving, mathematically gifted student, etc. appeared more than five times. Secondly, the keyword network analysis showed that the keywords-mathematics textbooks, school mathematics, mathematical problem solving, mathematical communications-have high connection centrality. Finally, we provided the limitations of this study and suggested future research.

• Journal of The Korean Association For Science Education
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• v.35 no.3
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• pp.419-429
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• 2015

In this study, we explored students' epistemological framing during scientific argumentation and how interactions among group members influenced group argumentation. Twenty-one gifted science students divided into groups of three or four participated in this study. Students' discussions related to data interpretation concerning the rate of photosynthesis were analyzed. Students' activities were videotaped in groups so the discourse could be transcribed and students' behavioral cues analyzed. Students' epistemological framing has been identified through analysis of their speech and behavioral responses to the anomalous data from the inquiry process. Subsequently, their sources of warrant and group argumentation levels were explored. We found out that group members framed the inquiry in two ways: "understanding phenomena" and "classroom game." Group members whose framing was "understanding phenomena" required other members to justify the anomalous data by examining its validity and reliability, which conclusively demonstrated a high level of argumentation. On the other hand, when group members used "classroom game" to frame their argumentation, they did not recognize the necessity of explaining the anomalous data; rather, these students used simple empirical justification to explain the data, reflecting a low level of argumentation. When students using different epistemological framing disagreed over interpretations of anomalous data throughout the discussion, clashes ensued that resulted in emotional conflict and a lack of discussion. Students' framing shifts were observed during the discussion on which group leaders seemed to have a huge influence. This study lays the foundation for future work on establishing productive framing to prompt scientific argumentation in science classrooms.

• Journal of Gifted/Talented Education
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• v.26 no.4
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• pp.699-719
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• 2016

Alternate pictures that are proven to be equivalent are in high demand to assess creative thinking and language skills. This study aimed to investigate the equivalence of three pictures ('Dog owners,' 'Lost Dog,' and 'Overslept') recently developed for use in a creative writing task. Middle school students (N=183) wrote a story in English based on one of the three prompts distributed randomly. Four writing features (fluency, syntactic complexity, lexical diversity, and temporality) were analyzed with Coh-Metrix and MANCOVA. The three prompts were largely equivalent in their capacity to detect differences among writers in all the features of writing. The difficulty levels of the three prompts, however, were not necessarily the same. Two prompts, Dog Owners and Lost Dog, were verified as equivalent prompts, and therefore, they are recommended as alternate forms to assess creative language skills in repeated measurements. The Overslept prompt had greater facility in eliciting diverse words and more temporal connectives in composing stories. The differential difficulty shown among the prompts suggests that the validity of using different picture versions in repeated assessment remains questionable unless those versions undergo equivalence verification.

• 대한공업교육학회지
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• v.33 no.1
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• pp.23-43
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• 2008

The purpose of this study is to provide some necessary baseline data to the information prodigy related research through the study on the brain left/right tendency of information prodigies. Subjects were 298 gifted students(59 information, 79 mathematics, 80 science, 40 invention, 40 social science) and 114 general students summing up 412 in the schools of Daejeon metropolitan area. 'Brain Tendency Test' developed by Torrance and modified by Ko in Korean was used as a tool to measure the prodigies' brain tendencies. Data analysis has been done with the $x^2$ test of frequency with the alpha = .05. The results of this study are as follows. 1) The information gifted students have tendencies of utilizing right brain hemisphere at the most, both left/right brain(whole brain) utilization at the second, and left brain utilization at the last. 2) There was statistically no difference between information prodigies and general students in the left/right brain tendency. 3) There was statistically mild evidence to support the notion that there are some differences in the brain tendency between the group of information prodigies and the group of other area of the prodigies. The degree of inclination to utilize the whole brain hemisphere for the prodigies of the other area was the highest compare to other left/right brain utilization while the information prodigies tend to utilize the right brain hemisphere at the most. 4) The female information prodigies have tendencies of utilizing while brain area at the most, right brain utilization at the second, and left brain utilization at the last contrary to the brain utilization tendencies in the male information prodigies which are the same as the brain utilization tendencies of the information prodigies. However there was no difference in brain tendencies statistically between the two groups since the female subjects were too small.