• Journal of the Korean GEO-environmental Society
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• v.15 no.2
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• pp.37-43
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• 2014

Natural disasters such as earthquakes and tsunamis occur suddenly, so that they cause massive loss of lives and property. Especially earthquakes represent a particularly severe threat because of the extensive damage accompanied by them. In Korea, an earthquake-resistant design has been rarely applied to a design or construction of slope. However, in resent years, the researches for earthquake-resistance have been performed because the importance on the earthquake-resistance is perceived and highlighted. Soil nail method, one of the slope stability methods, is excellent for its constructability and cost effectiveness, as compared with other stability methods. Also, this method has been widely used for reinforced construction for slope stability. The studies of soil nail method have been performed on the interaction behavior between nails and slopes as well as the varied load condition such as static load, dynamic load and so on. Nevertheless, there has been minimal research regarding the constraint condition of nail head. In this study, the numerical analysis was performed for identifying effect on slope stability for the constrain condition of the soil nail. The result shows that the resistance of constrained the nail head on reinforced slope is larger compared to the one of unconstrained nail head.

• Cross-Cultural Studies
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• v.26
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• pp.123-144
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• 2012

In the modern society in which globalization and localization proceed simultaneously, diversified and rapid migration of diaspora makes a new from of boundary off the frame of the state and the nation. This new border accompanies cultural change and racial mixture; retains ethnic conflict, the gap between rich and poor, alienation and discrimination, as well as power conflict; and extends its influence. Nowadays, the countries all over the world including Korea face problem of Diaspora in numerous forms. And each country takes an approach to the problem of the diaspora in the aspects of their society, culture and political technology. This implies that most countries, without understanding the new form of border which is alive and dynamic, define and conceptualize the diaspora in the frame of one state and one nation to carry forward the policies accordingly, resulting in inequal, incomplete and awkward homogenization. This study aimed to explore the identity of the diaspora, the core for the problem solving. Of course, studies about the identity of the diaspora have been continued until today and many great outcomes have been achieved. Nevertheless, this study aimed to explore the identity of the diaspora and the national policies which have a close interrelationship with it. It is because the study ultimately aimed to highlight the interrelationship between the destination countries, Russia and China, and the diaspora, through the definition and the classification of Russian diaspora and Chinese diaspora and the analysis of the national policies about that. However, the intention was not to distinguish superiority through the comparison of the polices about the diaspora between two countries, but to focus on the diversity of the identity of the diaspora through defining each different diaspora and paralleling the policies. Second, the reason for looking into the diaspora policies of these two countries is because it is judged the changes in the diaspora policies of each country is one of the active factors for the changes in the identify of the diaspora of each country and it is the basic research for the study on the identity of the diaspora. New migration of diaspora changes the identity of the state, and the state makes the policies and enforce the policies, resulting in the influence on the diaspora. This interaction acts as the growth factor for the new boundary. The causes of Russian diaspora and Chinese diaspora show apparent 'differences'. In parallel with this, the policies about the diaspora in Russia and China arouse 'differences' to the diaspora. The variation of the identity of the diaspora made by these differences will suggest other viewpoints on the diaspora, and these viewpoints will become the foundation for solving the problem of the diaspora in the present times.

• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.509-515
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• 2021

In this study, poly lactic-co-glycolic acid (PLGA) nanoparticles (PNP) were prepared through double (w/o/w) emlusion and emulsifying solvent-evaporation technique using PLGA, which has biocompatibility and biodegradability. To maximize stability and bioavailability of the particles, chitosan-coated PLGA nanoparticles (CPNP) were prepared by charge interaction between PNP and chitosan. We demonstrated that CPNP can be utilized as a drug carrier of oral administration. The chemical structure of CPNP was analyzed by ¹H-NMR and FT-IR, and all characteristic peaks appeared, confirming that it was successfully prepared. In addition, particle size and zeta potential of CPNP were analyzed using dynamic light scattering (DLS) while morphological images were obtained using transmission electron microscope (TEM). Thermal decomposition behavior of CPNP was observed through thermogravimetric analysis (TGA). In addition, the cytotoxicity of CPNP was confirmed by MTT assay at HEK293 and L929 cell lines, and it was proved that there is no toxicity confirmed by the cell viability of above 70% at all concentrations. These results suggest that the CPNP developed in this study may be used as an oral drug delivery carrier.

• Journal of The Korean Association For Science Education
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• v.41 no.5
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• pp.415-428
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• 2021

The COVID-19 pandemic has changed everything, even education. Last year when distance learning was introduced, science teachers faced many challenges to overcome. However, teachers adapted quickly, and in this year, it became the 'new normal'. In this situation, teachers are likely to habitually repeat past practices, but the context of the second year of distance learning is changing constantly, and teachers are asked to interpret the problem occurring in a situation and to adjust their practice for solving the problem with their teacher agency. In this study, we explore the emergence of science teacher agency and factors shaping teacher agency in the second year of distance learning and we focus on teachers' agentic practice that did not follow their past practice without reflection. For this purpose, we mainly analyze the semi-constructed interview of three science teachers. In the first year of distance learning, two teachers maintained their practice, not much different to face-to-face learning. However, one teacher reflected upon herself and started to recognize and solve her problems. Reflection for her practice can support this process. Another teacher changed her practice due to external suggestions, but it evolved her practice to fit the situation better, and her experience of last year helped her to adapt to the change. The other teacher who modified her practice to persist her professional purpose last year was consistently practicing in the second year and collaboration and autonomy can support her. This study shows the teachers' dynamic change of agency and the emergence for the relational interaction between teacher and context.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.2
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• pp.39-49
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• 2021

This study was conducted to establish practical goals for the viewing environment and interpretation and delivery system of cultural heritage and to create an viewing environment according to the classification of cultural heritage types, and the conclusions reached are as follows. First, five goals were set based on the international basic principles of the cultural heritage viewing environment and interpretation and delivery system. Second, based on the set goals, cultural heritage was classified into the first type 'disappeared and hidden heritage', the second type 'stuffed memory heritage', and the third type 'living memory heritage'. Third, the directions for creating the viewing environment for each type of cultural heritage were suggested. The first type has to be able to properly convey cultural heritage to visitors through excavation and digital technology. The second type needs a plan to deliver tangible and intangible values by combining various digital technologies with actual cultural heritage. The third type should emphasize the role of local residents in effectively enjoying the tangible and intangible values ??that already exist. Fourth, it proposed comprehensive considerations in the establishment of the cultural heritage viewing environment and interpretation and delivery system. Based on dynamic and sustainable heritage management, cultural heritage viewing should be valuable, satisfying and enjoyable. In addition, local communities should be actively involved, and tourism and conservation activities should be able to benefit the community. Establishment of a viewing environment should protect and strengthen the authenticity of cultural heritage.

• Journal of the Korea Convergence Society
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• v.10 no.6
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• pp.299-308
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• 2019

This quasi-experimental study was conducted to develop and implement a team facilitation program as well as to evaluate the effects of the program on Problem Based Learning (PBL) and how these influence on team dynamics. Data were collected in a convenient sample of 126 nursing students (intervention group=69; control group=57). Data were analyzed using ${\chi}^2$ test, T-test, and ANCOVA. SPSS23 was used. The intervention group received the PBL team facilitation program, whereas the control group received a human interaction training. The intervention group than the control group demonstrated significantly higher scores in a team dynamic among team members(F=10.35,p<0.01), trust among team members(F=9.86,p<0.01), communication(F=5.69,p<0.05), learning behavior of a team(F=4.57,p<0.05), and individual capability evaluation(F=5.12,p<0.05). Team performance was not significantly different between groups. This study reveals that the team facilitation program is an effective strategy to maximize the effects of PBL. We propose the need for educational strategy to support team function.

• Journal of Wetlands Research
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• v.21 no.1
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• pp.16-26
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• 2019

Wetlands that provide diverse ecosystem services, such as habitat provision and hydrological control of flora and fauna, constitute ecosystems through interaction between wetlands existing in a wetlandscape. Therefore, to evaluate the wetland functions such as resilience, it is necessary to analyze the ecological connectivity that is formed between wetlands which also show hydrologically dynamic behaviors. In this study, by defining wetlands as ecological nodes, we generated ecological networks through the connection of wetlands according to the dispersal model of wetland species. The characteristics of these networks were then analyzed using various network metrics. In the case of the dispersal based on a threshold distance, while a high local clustering is observed compared to the exponential dispersal kernel and heavy-tailed dispersal model, it showed a low efficiency in the movement between wetlands. On the other hand, in the case of the stochastic dispersion model, a low local clustering with high efficiency in the movement was observed. Our results confirmed that the ecological network characteristics are completely different depending on which dispersal model is chosen, and one should be careful on selecting the appropriate model for identifying network properties which highly affect the interpretation of network structure and function.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.6
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• pp.253-262
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• 2018

Oscillating Water Column (OWC) Wave Energy Converters (WEC) harness electricity through a Power-Take-Off (PTO) system from the induced-airflow by seawater oscillating inside a chamber. In general, an air chamber with a relatively small cross-sectional area is required compared to seawater chamber to obtain high-velocity air in the PTO system, and in order to simulate an accurate air flow rate in the air chamber, a three-dimensional study is required. In this study, the dynamic response of OWC-WEC that is equipped with the channel of seawater exchange for the case of irregular waves has been numerically studied. The open source CFD software, OLAFLOW for the simulation of wave dynamics to the openFOAM and FOAM-extend communities, was used to simulate the interaction between the device and irregular waves. Based on the numerical simulation results, we discussed the fluctuation characteristics of three dimensional air flow in the air-chamber, wave deformation around the structure and the seawater flow inside the channel of seawater exchange. The numerical results the maximum air flow velocity in the air-chamber increases as the Ursell value of the significant wave increases, and the velocity of airflow flowing out from the inside of air chamber to the outside is greater than the speed of flowing into the air chamber from the outside.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.926-931
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• 2011

Among various techniques for hydrogen production from organic wastewater, a dark fermentation is considered to be the most feasible process due to the rapid hydrogen production rate. However, the main drawback of it is the low hydrogen production yield due to intermediate products such as organic acids. To improve the hydrogen production yield, a co-culture system of dark and photo fermentation bacteria was applied to this research. The maximum specific growth rate of R. sphaeroides was determined to be $2.93h^{-1}$ when acetic acid was used as a carbon source. It was quite high compared to that of using a mixture of volatile fatty acids (VFAs). Acetic acid was the most attractive to the cell growth of R. sphaeroides, however, not less efficient in the hydrogen production. In the co-culture system with glucose, hydrogen could be steadily produced without any lag-phase. There were distinguishable inflection points in the accumulation of hydrogen production graph that resulted from the dynamic production of VFAs or consumption of it by the interaction between the dark and photo fermentation bacteria. Lastly, the hydrogen production rate of a repeated fed-batch run was $15.9mL-H_2/L/h$, which was achievable in the sustainable hydrogen production.

• International Area Studies Review
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• v.21 no.4
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• pp.223-245
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• 2017

This study is examined interaction between carbon market with stock market using a multivariate GARCH(DCC) model. Carbon market is EU ETS EUA price, stock market is the iron and cement stock price which has relatively energy intensive and massive carbon emissions sector in the industrial sector. It also analyzed changes in the correlation between the markets through an analysis of correlation coefficients. Moreover, it checked whether there was marketability expansion(or expansion of carbon emissions reduction) through the analysis above. As a result of empirical tests, it showed that the price spillover effect was insignificant. In addition, it represented that there was a weak correlation between the two markets since the volatility spillover effect disappeared in the second phase by an external shock(a financial crisis). Moreover, it was revealed that there were no significant changes although there was a weak upward trend in terms of the correlation between the carbon market and the stock market. This implies that emission rights could not expand marketability to financial market as a commodity(or did not play its natural role of the reduction of carbon emission).