• Journal of Korean Elementary Science Education
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• v.37 no.4
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• pp.402-415
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• 2018

This study aims to inquire into the U. S. elementary school teachers' storylines for science teaching methods, scientific knowledge and interactions with students. As research subjects, two American elementary school teachers, named Christina and Melissa, were selected. As test tools, this study adopted Storyline Test and semi-structured interviews. Firstly, in regard to the science teaching method, Christina evaluated that she gradually improved her science teaching skills up to positive 6 points, starting from 2 points in the first year of teaching career, while Melissa sustained a stable state with 5 points in the 9th year of teaching career, starting from 1 point in the first year of teaching career. It was found that both the teachers had more confidence in their science teaching methods by participating in various training programs. Secondly, Christina evaluated her scientific knowledge in the first year of teaching career as 4 points, but evaluated her present scientific knowledge as stable as 6 points since she started studying teaching materials actively, discussing with other teachers and having more ability of application through science class integrated with other school subjects, in the 7th year of her teaching career. On the other hand, Melissa evaluated her scientific knowledge in the first year of teaching career as 1 point since she did not exactly know what to teach elementary school students, but in the 6th year of teaching career, she sustained a stable state with points through joint-activities with other teachers. It was found that chances to research with other teachers had important effect on both the teachers' confidence in scientific knowledge. Thirdly, in regard to interactions with students in science class, Christina said that she did not have any interaction with students when instructing inquiry activities in the first year of teaching career, but since the 10th year of her teaching career, she had sustained a stable state with 6 points through active interaction with students, by leading learning projects and science competitive exhibitions, etc. On the other hand, Melissa evaluated her interaction with students in the first year of teaching career as 1 point because her class was reading-oriented, but since the 9th year of teaching career, she had sustained a stable state with 6 points so far, by developing inquiry activity strategies to improve interaction with students. Overall, it was found that inquiry activities played a central role in improving both the teachers' interaction with students.

• Biomolecules & Therapeutics
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• v.27 no.6
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• pp.522-529
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• 2019

M1/M2 polarization of immune cells including microglia has been well characterized. It mediates detrimental or beneficial roles in neuroinflammatory disorders including cerebral ischemia. We have previously found that sphingosine 1-phospate receptor subtype 1 ($S1P_1$) in post-ischemic brain following transient middle cerebral artery occlusion (tMCAO) can trigger microglial activation, leading to brain damage. Although the link between $S1P_1$ and microglial activation as a pathogenesis in cerebral ischemia had been clearly demonstrated, whether the pathogenic role of $S1P_1$ is associated with its regulation of M1/M2 polarization remains unclear. Thus, this study aimed to determine whether $S1P_1$ was associated with regulation of M1/M2 polarization in post-ischemic brain. Suppressing $S1P_1$ activity with its functional antagonist, AUY954 (5 mg/kg, p.o.), attenuated mRNA upregulation of M1 polarization markers in post-ischemic brain at 1 day and 3 days after tMCAO challenge. Similarly, suppressing $S1P_1$ activity with AUY954 administration inhibited M1-polarizatioin-relevant $NF-{\kappa}B$ activation in post-ischemic brain. Particularly, $NF-{\kappa}B$ activation was observed in activated microglia of post-ischemic brain and markedly attenuated by AUY954, indicating that M1 polarization through $S1P_1$ in post-ischemic brain mainly occurred in activated microglia. Suppressing $S1P_1$ activity with AUY954 also increased mRNA expression levels of M2 polarization markers in post-ischemic brain, further indicating that $S1P_1$ could also influence M2 polarization in post-ischemic brain. Finally, suppressing $S1P_1$ activity decreased phosphorylation of M1-relevant ERK1/2, p38, and JNK MAPKs, but increased phosphorylation of M2-relevant Akt, all of which were downstream pathways following $S1P_1$ activation. Overall, these results revealed $S1P_1$-regulated M1/M2 polarization toward brain damage as a pathogenesis of cerebral ischemia.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.362-373
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• 2021

This study sought to explore the enhancement of the introduction of teaching and learning methods for Problem Based Learning (PBL) and the evaluation factors to evaluate them effectively through an understanding lecture in Cultural Content Planning. It was intended to incorporate a practical zero-volume education methodology of problem-oriented learning and sufficient leading learning to reflect storytelling in the entire process of completing a cultural content with culture, cultural content, and content planning. To this end, the role of teaching methods should be faithful to ensure that teamwork and cooperation can be done organically according to the educational field, practice and situation. Students who take classes were asked to meet demand, reflect it through surveys, apply real-world problems, and acquire the entire course. Learners had to cooperate with each other until planning cultural content and completing the results through classes, and they evaluated themselves and colleagues in teamwork until the last result was completed from creative ideas. The results were shared together and the students were able to investigate the necessary PBL evaluation factors for themselves, and the prior research and survey on the method of PBL evaluation was conducted to derive the factors of understanding of cultural content planning. The derived assessment elements were able to identify priorities between the assessment elements using basic statistics, word cloud analysis, and AHP analysis. The components of the assessment derived were communication skills, basic knowledge, reasoning process, expertise, and evaluation techniques. Through this article, I was able to lead the understanding of cultural content planning to problem-oriented learning classes and encourage students to be familiar and smooth.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.221-231
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• 2021

In the present study, numerical simulation was performed to investigate aerodynamic characteristics of a ducted fan-upper/lower vanes system in hover. Sensitivity analysis of aerodynamic forces for a system component was conducted with the deflection angle of upper vanes varying but at the constant rotational speed and the collective pitch angle of fan blades. Then, vane control performance and duct airload distributions were analyzed in detail to physically understand operating mechanisms of individual vane and interference effect between duct and vanes. Finally, new control concept of operating upper vanes has been proposed to improve the control performance of the full configuration. It is found that the side force and rolling moment of upper vanes increase linearly with the variation of those deflection angle; however, the total side force is significantly small due to the reaction force acted on the duct. It is also found that upper vanes close to the duct contraction side have a key role in changing vane control forces. It is revealed that the duct suction pressure is induced by the interaction with the suction side of upper vanes, while duct pressure recovery by the interaction with the pressure side, leading to increase in duct asymmetric force. When four upper vanes are kept in situ at 0° deflection angle or removed, the total control performance was improved with duct asymmetric force reduced and the total magnitude of roll remarkably increasing up to 80%.

• Korean Journal of Labor Studies
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• v.23 no.2
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• pp.277-306
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• 2017

This article empirically explores the impact of minijobs in the wake of the Hartz reform in Germany on women's employment relationship. Theoretically it is of great significance to examine whether the minijobs play an active role as a bridge in leading the minijobbers to regular, socially secured jobs or not. Several interviews as well as secondary data I could get during my sabbatical in 2015 were used to test the theory. One of the main findings was the fact that the minijob labor market opened doors wide for women in Germany, particularly for career-interrupted women, students or pensioners. However, the minijob can easily become a trap of lowest income and poverty for women. Most women minjobbers cannot go over to regular, socially secured jobs. Especially in terms of collective industrial relations, it considerably damages the power of industrial unions and the legal binding force of collective agreement. In conclusion, this study makes it clear that the labor market segmentation theory rather than the transitional labor market theory is valid in accounting for the reality of minijob in Germany. In other words, the minijob in Germany has a Toijan Horse Effect. It also suggests, from a practical viewpoint, that German industrial unions or works councils organize the minijobbers and that the coverage of collective agreements be extended to the minijobbers. Consequently, the time-selective part-timer model put into practice in Korea in 2014 is not only invalid but also undesirable.

• Food Science and Industry
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• v.53 no.4
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• pp.390-396
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• 2020

We investigated the anti-obesity effect of Gelidium elegans extract (GE) on 3T3-L1 preadipocytes and a high-fat-diet (HFD)-induced mouse model. The results of the present study demonstrated that GE prevents weight gain induced by a high-fat diet (HFD) by modulating the adenosine monophosphate-activated protein kinase (AMPK)-PR domain-containing 16 (PRDM16)-uncoupling protein-1 (UCP-1) pathway in a mice model. Moreover, in vitro results show that GE suppressed adipocyte differentiation by modulating adipogenic regulators, stimulated lipolysis by activating ATGL, and inhibited adipogenesis by downregulating various enzymes associated with triglyceride synthesis. GE was also found to upregulate AMPK phosphorylation as well as the expression of UCP1 and PRDM16 proteins, leading to measurable changes in the beige-like phenotype differentiation of 3T3-L1 cells. Taken together, these findings suggest the role of GE as a functional food ingredient extracted from Gelidium elegans to increase energy expenditure and anti-obesity efficacy.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.931-941
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• 2020

There is a growing interest this paper for ocean sensing where autonomous vehicles can play an essential role in assisting engineers, researchers, and scientists with environmental monitoring and collecting oceanographic data. This study was conducted to develop a rigid sail for the autonomous sailing drone. Our study aims to numerically analyze the aerodynamic characteristics of curvy twin sail and compare it with wing sail. Because racing regulations limit the sail shape, only the two-dimensional geometry (2D) was open for an optimization. Therefore, the first objective was to identify the aerodynamic performance of such curvy twin sails. The secondary objective was to estimate the effect of the sail's spacing and shapes. A viscous Navier-Stokes flow solver was used for the numerical aerodynamic analysis. The 2D aerodynamic investigation is a preliminary evaluation. The results indicated that the curvy twin sail designs have improved lift, drag, and driving force coefficient compared to the wing sails. The spacing between the port and starboard sails of curvy twin sail was an important parameter. The spacing is 0.035 L, 0.07 L, and 0.14 L shows the lift coefficient reduction because of dramatically stall effect, while flow separation is improved with spacing is 0.21 L, 0.28 L, and 0.35 L. Significantly, the spacing 0.28 L shows the maximum high pressure at the lower area and the small low pressure area at leading edges. Therefore, the highest lift was generated.

• Economic and Environmental Geology
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• v.54 no.4
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• pp.465-473
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• 2021

This numerical study aims at analyzing the effect of flow characteristics, caused by geometrical features such as intersecting angles, on solute mixing at fracture junctions. It showed that not only Pe, the ratio of advection to diffusion, but also the intersecting angles played an important role in solute mixing at the junction. For the intersection angles less than 90°, the fluid flowed to the outlet in the same direction as the injected flow direction, which increased the contact at the junction with the streamlines coming from the different inlets. On the other hand, for the intersecting angles greater than 90°, the fluid flowed out to the outlet opposite to the flow direction in the inlet, leading to minimizing the contact at the junction. Therefore, in the former case, solute mixing occurred even at high Pe, and in the latter case, solutes transport along the streamlines even at low Pe. For Pe < 1, the complete mixing model was known to occur, but for the intersecting angle greater than 150°, no complete solute mixing occurred. Overall, the transition from the complete mixing model to the streamline-routing model occurred for Pe = 0.1 - 100, but it highly depended on the intersecting angles. Specifically, the transition occurred at Pe = 0.1 - 10 for intersecting angles ≧ 150° and at Pe = 10 - 100 for intersecting angles ≦ 30°. For Pe > 100, the streamline-routing model was dominant regardless of intersecting angles. For Pe > 1,000, the complete streamline-routing model appeared only for the intersecting angles greater than 150°. For the intersecting angles less than 150°, the streamline-routing model dominated over the complete solute mixing, but solute mixing still occurred at the fracture junction.

• Journal of the Daesoon Academy of Sciences
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• v.36
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• pp.79-116
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• 2020

This paper examines the nature of the transcendent, absolute, and personal host of ancient philosophical notions of the Higher Power (天觀 cheongwan, literally 'view of heaven'), which flows through Toegye's Principle of Reality (Li), Dasan's Supreme God (Sangje), Suwun's Lord of Heaven (Cheonju), and Jeungsan's Supreme God (Sangje). This confirms the sentiment that despite the conceptual differences relating to appearance, as represented by the Principle of Reality, the Dasanian Supreme God, the Suwunian Lord of Heaven, and the Jeungsanian Supreme God, the contents of these notions do not substantially differ from one another. Moreover, the nature of the ancient philosophical notions of the Higher Power lead to Toegye's Principle of Reality, the Dasanian Supreme God, the Suwunian Lord of Heaven, and the Jeungsanian Supreme God. Toegye emphasized the nature of the Principle of Reality as transcendental and absolute, and also as a personal host. This led to Dasan's Supreme God, and furthermore, it also inspired the Suwunian Lord of Heaven and the Jeungsanian Supreme God. In other words, although Dasan criticizes the Principle of Reality and presupposes a Supreme God, a personal host, this is not especially different from the character or role of Toegye's Principle of Reality. It likewise does not especially differ from the Suwunian Lord of Heaven or the Jeungsanian Supreme God. On the contrary, without the foundation of the religious tradition behind Toegye's Principle of Reality, it would have been difficult to establish a theoretical system leading to the upper system of the Dasanian Supreme God, the Suwunian Lord of Heaven, or the Jeungsanian Supreme God. Of course, the construction of heaven and earth, which in Daesoon Thought is actually performed by the Jeungsanian Supreme God, is, in fact, fundamentally different from Toegye, Dasan, and Suwun's previous notions of the Higher Power. In this sense, it is necessary to present more clearly the religious character of Toegye's Principle of Reality.

• Journal of Korean Elementary Science Education
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• v.40 no.4
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• pp.545-555
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• 2021

This study aims to analyze research trends by the period of elementary science education journal. A total of 1047 papers were analyzed from Volume 1 No. 1 in 1983 to Volume 39 No. 4 in 2020. The results of the study are as follows: First, the period of elementary science education journals was divided into infancy, settlement, development, and retainment period according to the number of papers. Second, the ratio of research by more than three scholars, pure or funded research was decreasing. Third, the study subjects had a high rate of research on elementary school students and elementary school teachers. Fourth, research methods were mainly research studies and experimental studies, and qualitative analysis and mixed analysis studies were increasing as data analysis methods. Fifth, the occupation of the first author was professor (45.6%), teacher (39.8%), graduate student (10.6%), and researcher (1.7%) in that order. Sixth, the regions of the corresponding author were concentrated in Seoul and Gyeongin, the metropolitan areas. Finally, in order for the "Elementary Science Education" journal to continue to play a pivotal role in leading elementary science education in the future, efforts to improve the overall journal and continuous participation and cooperation of domestic and foreign researchers, academic executives, members, and educational institutions are required.