• ALGAE
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• v.33 no.3
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• pp.205-214
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• 2018

Red algae in the genus Portieria produce secondary halogenated monoterpenes, which are effective deterrents against herbivores, as secondary metabolites. Portieria hornemannii samples from various sites contain different concentrations of these metabolites, suggesting the existence of genetic diversity and cryptic species. To evaluate the genetic diversity and species distribution of Portieria in the northwest Pacific, we analyzed rbcL sequences of samples collected from Korea, Japan, and Taiwan. The phylogenetic analysis revealed five distinct lineages at the species level. One was recognized as Portieria japonica and the others were cryptic lineages in P. hornemannii. The rbcL haplotypes of P. japonica were genetically fragmented into two subgroups of geographic origin; Korean and Japanese. The four cryptic lineages within P. hornemannii were also geographically structured at a much finer scale. These results suggest that different genetic lineages in Portieria evolved from variable microhabitats, consequently influencing secondary metabolites. Further study is required to resolve the relationships between genetic and secondary metabolite variations in Portieria.

• Archives of Craniofacial Surgery
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• v.23 no.2
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• pp.83-88
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• 2022

Nevus sebaceous of Jadassohn is a congenital cutaneous hamartoma with epidermal, sebaceous, follicular, and apocrine structures that usually appears at birth or in early childhood. It has the potential to generate a variety of secondary neoplasms of different lineages, and the risk increases with patient age. Although multiple neoplasms may occasionally arise within the same lesion, the coexistence of more than five secondary tumors is extremely rare. Here we report a case of seven secondary tumors including syringocystadenoma papilliferum, desmoplastic trichilemmoma, sebaceoma, trichoblastoma, pigmented trichoblastoma, sebaceous adenoma, and tumor of follicular infundibulum arising within a nevus sebaceous. The complete diagnosis relies on the histopathological analysis of multipoint biopsies and delicate pathological sections.

• Asian Journal of Innovation and Policy
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• v.12 no.3
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• pp.345-362
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• 2023

As the widespread adoption and proliferation of electric vehicles continue, the secondary battery market is experiencing rapid growth. However, lithium-ion batteries, which constitute a majority of secondary batteries, present high risks of fire and explosion. Solid-state batteries are thus garnering attention as the next-generation batteries since they eliminate fire hazards and significantly reduce the risk of explosions. Against this background, the study aimed to analyze research trends and provide insights by examining 2,927 domestic papers related to solid-state batteries over the past decade (2013-2022). Specifically, we used topic modeling to extract major keywords associated with solid-state batteries research and to explore the network characteristics across major topics. The changes in research on solid-state batteries were analyzed in-depth by calculating topic dominance by year. The findings provide an overview of the emerging trends in domestic solid-state battery research, and might serve as a valuable reference in shaping long-term research directions.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5127-5132
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• 2016

Objective: The aim of this study was to identify associations of internal motivation, perceived health competency, and health literacy with primary and secondary cancer prevention. Methods: A telephone survey was conducted with a sample of 2,700, 30-69 year olds, proportionally extracted from Gangwon Province, South Korea. The dependent variables were actions in primary and secondary prevention and the explanatory variables were 13 questions in three areas: internal motivation (4 items), perceived health competency (4 items), and health literacy (5 items). Result: Multiple linear regression analysis showed that internal motivation, perceived health competency, and health literacy positively impacted primary prevention after controlling for gender and age. As internal motivation, perceived health competency, and perceived literacy increased by 1 point, primary prevention scores increased by 0.11, 0.11, and 0.07 points, respectively. In addition, logistic regression results for secondary prevention showed that health literacy had a positive impact on secondary behavior. As health literacy increased by 1 point, the odds ratio of the practice of secondary prevention was 1.4 times higher. Conclusion: This study suggests that primary and secondary prevention of cancer are significantly related to intrinsic motivation factors, perceived health competency, and actual health literacy. Health literacy concepts that cover the capacity of health management in comprehensive areas need to be applied to education and promotion for improvement of primary and secondary prevention of cancer.

• The KSFM Journal of Fluid Machinery
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• v.12 no.2
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• pp.8-16
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• 2009

The objective of this study is to investigate the three-dimensional turbulence flow characteristics of a rotor passage of an one-stage axial flow gas turbine and to investigate the effects of a boundary layer fence installed on the hub endwall of the rotor passage. Secondary flows occurring within the rotor passage (e.g. horseshoe vortex, passage vortex, and cross flow) cause secondary loss and reduce turbine efficiency. To control these secondary flows, a boundary layer fence measuring half the height of the thickness of the inlet boundary layer was installed on the hub endwall of the rotor passage. This study was performed numerically. The results show that the wake and secondary flows generated by the stator reduced the rotor load to constrain the development of cross flow and secondary flow reinforced by the rotor passage. In addition, the secondary vortices occurring within the rotor passage were reduced by the rotation of the rotor. Although, the boundary layer fence induced additional vortices, giving rise to an additional loss of turbine, its presence was shown to reduce the total pressure loss when compared to effects of the case without fence regardless of the relative position of blades by enervating secondary vortices occurred within the rotor passage.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.1
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• pp.58-65
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• 2012

In this study, to reduce the motion of the vessels resulting from resonance and secondary undulation by long-period waves, numerical review on the control performance of resonator was carried out by attaching the resonator to the established harbor of real waters. In the numerical analysis, CGWAVE MODULE of commercial software SMS(Surface water Modeling System), a finite element model based on 2-dimensional elliptical mild slope equation was applied, and through comparative analysis of the existing experiments and analysis results on the rectangular model ports, the validity of the friction coefficients in which validity and effectiveness of SMS on the secondary undulation analysis is applied was verified. Based on this, the control performance of resonator was confirmed through comparative review of the secondary undulation according to whether or not to attach the resonator to rectangular harbor. In addition, to reduce long-period motion of the moored vessels and the secondary undulation which may occur in Pohang new port, the method to move the resonant period which causes abnormal motion of the vessels to long-term one was discussed through application of the resonators with various sizes, thereby identifying the availability.

• Journal of the Korean Society of Earth Science Education
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• v.11 no.2
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• pp.78-89
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• 2018

The purpose of this study is to explore ways to improve developing exam questions for Earth science education by analyzing exam trend of Earth science education in the secondary-school teacher employment test (TET, hereafter). For this purpose, we developed an analysis framework to analyze items of Earth science education in the secondary-school TET, and this analysis framework covers required courses for 'theory of Earth science education' of 'Earth science teaching certificate courses'. The analysis framework consists of big categories, assessment domains, and assessment components. We divided system changes in secondary-school TET into 4 types, and analyzed exams of 2014-2018 school year, which is the existing exam system. According to the results, 22-24 points out of 80 have been allotted to Earth science education. Among assessment domains, Earth science Teaching & Learning domain has taken the highest percentage of scores and item numbers, followed by Earth science inquiry, history & philosophy of science, etc. For each domain, we analyzed exam tendencies in detail. Based the results, we suggested ways to improve developing exam questions for Earth science education in the secondary-school TET, and ways to improve curriculum for Earth science education in the teacher education program.

• Journal of Korean Home Economics Education Association
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• v.33 no.3
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• pp.129-142
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• 2021

The purpose of this study was to provide educational data on teaching clothing culture by examining the effects of clothing lifestyle on attitudes toward teachers' clothing for 270 secondary school pre-service teachers. For data analysis, factor analysis, Cronbach's α reliability coefficients, t-tests, one-way analysis of variance, Duncan's multiple comparison verification, and multiple regression analysis were performed using SPSS 24.0 program. As a result of the study, first, the clothing lifestyle of secondary school pre-service teachers was classified as fashion trend orientation, clothing importance orientation, attractive appearance orientation, and economic orientation factors. In addition, the attitude toward teacher's clothes was classified into activity, fashionability, and modesty factors. Second, there was a statistically significant difference in the attitudes toward clothing lifestyle and teacher clothing of secondary school pre-service teachers according to gender and year in college, which are demographic variables. Third, it was found that the clothing lifestyle of secondary school pre-service teachers, who are Generation Z, had an effect on the attitude toward teacher clothes. In conclusion, this study proposes that school administrators and teachers should depart from the former stereotypes about teacher clothes and to encourage a culture in which teachers can dress and perform their role of teaching according to individual's changing lifestyles.

• Analytical Science and Technology
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• v.10 no.5
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• pp.1087-1104
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• 1997

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1274-1279
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• 2011

The purpose of this paper is to present the manufacturing defect and damage pattern of a 3 phase 22.9/3.3kV oil immersed transformer, as well as to present an objective basis for the prevention of a similar accident and to secure data for the settlement of PL related disputes. It was found that in order to prevent the occurrence of accidents to transformers, insulating oil analysis, thermal image measurement, and corona discharge diagnosis, etc., were performed by establishing relevant regulation. The result of analysis performed on the external appearance of a transformer to which an accident occurred, the internal insulation resistance and protection system, etc., showed that most of the analysis items were judged to be acceptable. However, it was found that the insulation characteristics between the primary winding and the enclosure, those between the ground and the secondary winding, and those between the primary and secondary windings were inappropriate due to an insulating oil leak caused by damage to the pressure relief valve. From the analysis of the acidity values measured over the past 5 years, it is thought that an increase in carbon dioxide (CO2) caused an increase in the temperature inside the transformer and the increase in the ethylene gas increased the possibility of ignition. Even though 17 years have passed since the transformer was installed, it was found that the system's design, manufacture, maintenance and management have been performed well and the insulating paper was in good condition, and that there was no trace of public access or vandalism. However, in the case of transformers to which accidents have occurred, a melted area between the upper and the intermediate bobbins of the W-phase secondary winding as well as between its intermediate and lower bobbins. It can be seen that a V-pattern was formed at the carbonized area of the transformer and that the depth of the carbonization is deeper at the upper side than the lower side. In addition, it was found that physical bending and deformation occurred inside the secondary winding due to non-uniform pressure while performing transformer winding work. Therefore, since it is obvious that the accident occurred due to a manufacturing defect (winding work defect), it is thought that the manufacturer of the transformer is responsible for the accident and that it is lawful for the manufacture to investigate and prove the concrete cause of the accident according to the Product Liability Law (PLL).