• Clean Technology
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• v.28 no.3
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• pp.203-209
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• 2022

An environmental evaluation was conducted by employing LCA methodology for a mechanical seal manufacturing process that uses recycled silicon recovered from end-of-cycle PV modules. The recycled silicon was purified and reacted with carbon to synthesize β-SiC particles. Then the particles underwent compression molding, calcination and heat treatment to produce a product. Field data were collected and the potential environmental impacts of each stage were calculated using the LCI DB of the Ministry of Environment. The assessment was based on 6 categories, which were abiotic resource depletion, acidification, eutrophication, global warming, ozone depletion and photochemical oxidant creation. The environmental impacts by category were 45 kg CO₂ for global warming and 2.23 kg C₂H₄ for photochemical oxide creation, and the overall environmental impact by photochemical oxide creation, resource depletion and global warming had a high contribution of 98.7% based on weighted analysis. The wet process of fine grinding and mixing the raw silicon and carbon, and SiC granulation were major factors that caused the environmental impacts. These impacts need to be reduced by converting to a dry process and using a system to recover and reuse the solvent emitted to the atmosphere. It was analyzed that the environmental impacts of resource depletion and global warming decreased by 53.9% and 60.7%, respectively, by recycling silicon from end-of-cycle PV modules. Weighted analysis showed that the overall environmental impact decreased by 27%, and the LCA analysis confirmed that recycling waste modules could be a major means of resource saving and realizing carbon neutrality.

• Journal of Family Resource Management and Policy Review
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• v.27 no.1
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• pp.25-39
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• 2023

This study aims to analyze the differences in the strength of single-parent families based on family characteristics. Using a sample of 267 female single parents, we explore the factors that impact family strength. We found that several variables impact the strength of families headed by a female single parent: the length of time members had lived together as a single-parent family, co-residents, interactions with ex-spouses, full-time work, and household income. Based on these findings, we suggest that the length of time that single-parent families have lived together is an important criterion for planning and evaluating the family policies and services offered by healthy family support centers. Furthermore, in the context of family resource management, family policies and programs that address time management and family life planning for full-time single parents should be developed and implemented.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.3
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• pp.107-121
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• 2023

The assessment of perceived naturalness aims to elucidate the human perception and explain the interaction between natural environments and humans. The perception of ecological assets that exhibit distinct characteristics within a specific region can manifest in various representations. Based on the users' perceptions and interviews regarding ecological assets, this study assessed the perceived naturalness from a cultural services perspective. Specifically, the discussions on Ansan City's ecological assets and revolved around the inherent value of naturalness in dimensions, such as the necessity for conservation and the sustainable development of ecological assets, the perception of ecosystem benefits, the representativeness as a local asset, and usability. Subsequently, the Q method was employed to present 25 representative ecological assets to 25 users. As a result, user groups with different value systems for each question were identified, and hypothetical personas for cultural service enjoyment were distinguished. The most representative persona among the 25 users was identified as AWP (a type that values the conservation of aquatic ecosystems, prefers waterfront landscapes, and enjoys walking). Since perceived naturalness is conceptually similar to the "benefits perceived by users" in evaluating ecosystem services, it can provide more practical evaluation criteria for cultural services.

• Korean Journal of Culture and Social Issue
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• v.16 no.1
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• pp.43-61
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• 2010

In Korea, Pbichim refers to a psychological state caused by emotional damages that can occur within close relationships. In this state, one might feel reluctant to express one's feelings directly to the other party. It is also possible that Pbichim transforms into anger. This study is aimed to define the term Pbichim as an indigenous psychological concept. In Korea, it is common to express one's feelings indirectly and read the other party's inward thoughts. Pbichim reflects those cultural aspects. In order to examine the representation of Pbichim in Korea, we developed a questionnaire consisting of 15 open-ended questions. The participants were 119 undergraduate and graduate students at Korea University, and the data was analyzed qualitatively. As a result, four different aspects of Pbichim (unsatisfied expectation, being ignored, being alienated, and power struggle) could be differentiated by the situation in which people are likely to present Pbichim. The personality traits of Pbichim, the way of relieving it, as well as positive and negative functions of Pbichim were also elicited. In addition, it was found that Pbichim (the concept that has been negatively perceived) has an important function in maintaining and improving an interpersonal relationship in Korea. Lastly, the importance of mind reading within a certain cultural context is discussed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.83-90
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• 2024

This study investigates the 3D printing characteristics of strain hardening cement composites (SHCC) reinforced by PVA fibers. Three SHCC mixtures with diverse fiber volume fractions (1.0% for F1.0 mixture, 1.5% for F1.5 mixture, and 1.8% for F1.8 mixture) were designed. Except for the F1.0 mixture, all mixtures met the necessary conditions for multiple micro-cracking, with higher fiber volume fractions more readily satisfying these conditions. The flow values of three SHCC mixtures were within the 3D printable range of 120~160 mm, exhibiting decreased flow values with increasing the fiber volume fractions. Observation of the printed SHCC surfaces indicated that the F1.0 mixture had a Level-3 (good) rating, while F1.5 and F1.8 were rated as Level-2 (average). Higher fiber volume fractions resulted in poorer surface quality, thus, further research needs to be performed for modulating SHCC mixture suitable for 3D printing. The uniaxial tension behavior showed that the F1.0 mixture failed at lower strain, whereas F1.5 and F1.8 exhibited higher strain performance with multiple micro-cracks occurring.

• Journal of The Korean Association For Science Education
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• v.27 no.7
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• pp.592-608
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• 2007

This study explored the types of conceptual change of 'force' within middle school students' conceptual ecologies. This qualitative study was implemented with the use of classroom observations and two interviews with the participants. 11 middle school students (7 females and 4 males) joined in this study. The interviews with the participants were conducted individually before and after the 'force' unit. The collected data were all transcribed and analyzed interpretively. The results of this study consisted of two parts. First, the participants' conceptual ecologies of 'force' were categorized into 4: epistemological commitments (fixed or interactional explanatory consistency), analogy (attribute, working), metaphysical beliefs (people-oriented ontology, animism, causationism, mixed), and past experiences. Second, two representative cases including 'stable' and 'transitional' states were explained based on the interactions within their own conceptual ecologies. We can see students' conceptions with the integrated perspective in the sense that this results tried to get contextual and interactional understandings of the status of the conception and the possibilities of conceptual change. In addition, it implied that conceptual change research should have the perspective of conceptual ecology evolution in the future.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.452-455
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• 2006

The in vitro cytoprotective and anti-oxidative effects of ursodeoxycholic acid, a major active compound from bear's gall were investigated in mouse brain microglia. In the present study, we wished to scrutinize the potential role of UDCA as an anti-neurodegenerative agent in neurodegenerative disease such as Alzheimer's disease. This concept was supported by the multiple preliminary studies in which UDCA has an anti-inflammatory effect in microglial cells. In the study, we found that $7.5\;{\mu}g/mL$ UDCA was effective in the protection of cells from $H_2O_2$ damage, a reactive oxygen, and the resuIt was coincided with the anti-apoptotic effect in DAPI staining. Moreover, the metal-catalyzed oxidation study showed that UDCA has antioxidant effect as much as ascorbic acid at $50{\sim}100\;{\mu}g/mL$. In conclusion, these study results suggested that neuro-degenerative diseases such as Alzheimer's disease probably caused by over-expressed beta amyloid peptide in elderly people can be controled by UDCA through an anti-inflammatory, anti-oxidative and anti-apoptotic effect. The evidences showed in the study may be references for more in-depth in vivo and clinical studies for a candidate of anti-neurodegenerative therapy in the near future.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.591-606
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• 2016

The purpose of this study is to develop the argumentation program to build scientific concepts on natural selection for science-gifted elementary students and to know how to implement this program. For this study, nine key concepts about natural selection such as the overproduction of offspring, limited resources, population stability, competition, variation, heredity of variation, differential survival, change of the population and speciation were selected through the literature study. The programs were developed by learning cycle instructional model. Argument writings and discourses have been collected, analyzed and compared before and after the program. Two questionnaires to compare pre and post concept change consist of multiple choice questionnaire and open-ended response question were developed and applied to 19 science-gifted elementary students. Sufficiency of the explanation and conceptual quality of the explanation were used to assess the quality of their arguments before and after the program. Discourse and visual models collected from the highest and lowest group about score improvement were compared. The scores of the gifted statistically improved significantly in multiple choice questionnaire. Students' alternative conceptions about natural selection at the beginning of the program decreased and changed scientifically after the program. Visual models drawn by the students supported the results as well. This study asserts that elementary science-gifted students are able to explain evolutionary perspectives about organism change and use the key concepts of natural selection. The study means that evolutionary perspective is possible to be reflected in elementary science curriculum for the gifted.

• Journal of Korea Water Resources Association
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• v.40 no.11
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• pp.887-898
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• 2007

A physically based semi-distributed model, SWAT was applied to the Chungju Dam upstream watershed in order to investigate the spatial and temporal characteristics of watershed sediment yields. For this, general features of the SWAT and sediment simulation algorithm within the model were described briefly, and watershed sediment modeling system was constructed after calibration and validation of parameters related to the runoff and sediment. With this modeling system, temporal and spatial variation of soil loss and sediment yields according to watershed scales, land uses, and reaches was analyzed. Sediment yield rates with drainage areas resulted in $0.5{\sim}0.6ton/ha/yr$ excluding some upstream sub-watersheds and showed around 0.51 ton/ha/yr above the areas of $1,000km^2$. Annual average soil loss according to land use represented the higher values in upland areas, but relatively lower in paddy and forest areas which were similar to the previous results from other researchers. Among the upstream reaches, Pyeongchanggang and Jucheongang showed higher sediment yields which was thought to be caused by larger area and higher fraction of upland than other upstream sub-areas. Monthly sediment yields at the main outlet showed same trend with seasonal rainfall distribution, that is, approximately 62% of annual yield was generated during July to August and the amount was about 208 ton/yr. From the results, we could obtain the uniform value of sediment yield rate and could roughly evaluate the effect of soil loss with land uses, and also could analyze the temporal and spatial characteristics of sediment yields from each reach and monthly variation for the Chungju Dam upstream watershed.

• Journal of Popular Narrative
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• v.25 no.4
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• pp.191-221
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• 2019

This study aims to analyze the post-humanistic imagination that has emerged as a major academic thesis in Korean literature, especially novels. In particular, this paper focuses on Cho Ha-hyung's two novels Chimera's Morning(2004) and A Prefabricated Bodhi Tree(2008), published in the early 2000s, for intensive analysis. Post-humanism can be seen as an extension of post-modernism that tried to overcome the limitations of modernity and seek to establish a new world view. In particular, this thought pays attention to the comprehensive understanding of how the rapid development of science and technology, which has developed since the 20th century, has changed the view of humanity and human-centered civilization itself. At the concrete level, it is developing in the direction of constructing a new subject idea by reflecting and dismantling Western-, reason-, and male-centered power mechanisms that are the core of modern civilization. Cho attempts to discover and re-illuminate the surrounding figures, non-humans, and objects that were not noticed in the classic works written in the past. This ideological flow reflects the fact that the concept of human beings, which had been dominated by the humanities in recent years, has been completely changed, and the natural science and technology perspective is applied to the discourse field in various ways. From the point of view of post-humanism, objects that have not been classified as humans and objects that were considered inferior to humans should be included in human or comparable levels. These questions generate interdisciplinary research tasks by involving the large categories of philosophy, such as ontology, epistemology and empirical fields, as well as calling for the participation of the entire literature, science and social sciences. Against the backdrop of a disaster-hit world, Chimera's Morning and A Prefabricated Bodhi Tree depict human beings as variants transformed by bio-technology, and creatures made out of the artificial intelligence built by computer simulations. Post-humanistic ideas in Cho's novels provide a reflective opportunity to comprehensively reconsider the world's shape and human identity reproduced in the text, and to re-explore boundary lines and hierarchy order that distinguish between human and non-human.