• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.755-770
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• 2023

Due to recent severe climate change, abnormal weather phenomena, and other factors, the frequency and magnitude of natural disasters are increasing. The need for disaster management using artificial satellites is growing, especially during large-scale disasters due to time and economic constraints. In this study, we have summarized the current status of next-generation medium-sized satellites and microsatellites in operation and under development, as well as trends in satellite imagery analysis techniques using a large volume of satellite imagery driven by the advancement of the space industry. Furthermore, by utilizing satellite imagery, particularly focusing on recent major disasters such as floods, landslides, droughts, and wildfires, we have confirmed how satellite imagery can be employed for damage analysis, thereby establishing its potential for disaster management. Through this study, we have presented satellite development and operational statuses, recent trends in satellite imagery analysis technology, and proposed disaster response strategies that utilize various types of satellite imagery. It was observed that during the stages of disaster progression, the utilization of satellite imagery is more prominent in the response and recovery stages than in the prevention and preparedness stages. In the future, with the availability of diverse imagery, we plan to research the fusion of cutting-edge technologies like artificial intelligence and deep learning, and their applicability for effective disaster management.

• Clinical and Experimental Pediatrics
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• v.52 no.7
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• pp.824-831
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• 2009

Purpose : We aimed to investigate the efficacy of and functional recovery after intracerebral transplantation of different doses of mouse mesenchymal stem cells (mMSCs) in immature rat brain with hypoxic-ischemic encephalopathy (HIE). Methods : Postnatal 7-days-old Sprague-Dawley rats, which had undergone unilateral HI operation, were given stereotaxic intracerebral injections of either vehicle or mMSCs and then tested for locomotory activity in the 2nd, 4th, 6th, and 8th week of the stem cell injection. In the 8th week, Morris water maze test was performed to evaluate the learning and memory dysfunction for a week. Results : In the open field test, no differences were observed in the total distance/the total duration (F=0.412, P=0.745) among the 4 study groups. In the invisible-platform Morris water maze test, significant differences were observed in escape latency (F=380.319, P<0.01) among the 4 groups. The escape latency in the control group significantly differed from that in the high-dose mMSC and/or sham group on training days 2-5 (Scheffe's test, P<0.05) and became prominent with time progression (F=6.034, P<0.01). In spatial probe trial and visible-platform Morris water maze test, no significant improvement was observed in the rats that had undergone transplantation. Conclusion : Although the rats that received a high dose of mMSCs showed significant recovery in the learning-related behavioral test only, our data support that mMSCs may be used as a valuable source to improve outcome in HIE. Further study is necessary to identify the optimal dose that shows maximal efficacy for HIE treatment.

• Journal of The Korean Association For Science Education
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• v.37 no.4
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• pp.565-575
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• 2017

This study analyzes the epistemic considerations and the argumentation level revealed in the discourse of the key concept of natural selection for science-gifted elementary students. The paper analyzes and discusses the results of a three-student focus group, drawn from a cohort of twenty gifted sixth-grade elementary students. Nature, generality, justification, and audience were used to analyze epistemic consideration. Learning progression in scientific argumentation including argument construction and critique was used to analyze students' scientific argumentation level. The findings are as follows: First, Epistemic considerations in discourse varied between key concepts of natural selection discussed. The nature aspect of epistemic considerations is highly expressed in the discourse for all natural selection key concepts. But the level of generality, justification and audience was high or low, and the level was not revealed in the discourse. In the heredity of variation, which is highly expressed in terms of generality of knowledge, the linkage with various phenomena against the acquired character generated a variety of ideas. These ideas were used to facilitate engagement in argumentation, so that all three students showed the level of argumentation of suggestions of counter-critique. Second, students tried to explain the process of speciation by using concepts that were high in practical epistemic considerations level when explaining the concept of speciation, which is the final natural selection key concept. Conversely, the concept of low level of epistemic considerations was not included as an explanation factor. The results of this study suggest that students need to analyze specific factors to understand why epistemological decisions are made by students and how epistemological resources are used according to context through various epistemological resources. Analysis of various factors influencing epistemological decisions can be a mediator of the instructor who can improve the quality and level of the argumentation.