• Korean Journal of Environmental Biology
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• v.41 no.1
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• pp.41-53
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• 2023

E171, a mixture of titanium dioxide, has been widely used as a food additive due to its whitening effect and low toxicity. However, it has been proven that E171 is no longer safe for public health. So far, there are insufficient studies on the toxic effects of E171 on organisms especially using standardized test methods. In this study, toxicity assessments of E171 to two aquatic species, water flea (Daphnia magna) and zebrafish (Danio rerio), were performed using modified standardized test methods based on the physicochemical properties of E171. The hydrodynamic diameter, polydispersity index, and turbiscan stability index (TSI) were measured to ensure the dispersion stability of E171 in exposure media during the test period. The EC₅₀ for immobilization of water flea was 141.7 mg L^-1 while zebrafish was not affected until 100 mg L^-1 of E171. Measurements of reactive oxygen species (ROS) and antioxidant enzyme activities confirmed that E171 induced oxidative stress, leading to the activation of superoxide dismutase and catalase in both water flea and zebrafish, although the expression of antioxidant enzyme genes differed between species. These results suggested the potential risk of E171 to aquatic organisms and provided toxicological insights into the impacts of E171 on the environment.

• Radiation Oncology Journal
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• v.36 no.2
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• pp.171-171
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• 2018

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.171.1-171.1
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• 2003

In some tissues 17b-estradiol (E2) is known to increase endothelial NOS expression. In the present study we examined the effects of E2 on estrogen receptors (ERa and b) and inducible nitric oxide synthase (iNOS) expression and analyzed the mechanisms in rat peritoneal macrophages. (omitted)

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.171.2-171.2
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• 2005

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.171-171
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• 2017

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.171.1-171.1
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• 2000

• Cement Symposium
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• no.31
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• pp.171-179
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• 2004

• Educational Technology International
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• v.11 no.1
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• pp.171-192
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• 2010

This study was to investigate the elaborated project based learning model for scientifically gifted in the context of R & E project learning. It is important for the scientifically gifted to provide the appropriate learning environments instead of general learning model for the gifted. Although R & E project learning model is effective, the model has the limitations of managing the course for the scientifically gifted. To improve R & E learning model, the elaborated project based learning model was suggested with integration of both project based learning model and goal based scenario. The elaborated project-based learning model was comprised with 'basic learning process', 'elaboration through inquiry', and 'presentation and reflection'. To measure the satisfaction, eighty scientifically gifted students participated in the class. The result shows that learners were satisfied with the elaborated project-based learning up to 90%, and teachers were satisfied with this model up to 77%.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.169-171
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• 2023

eLoran 신규송신국 구축 진행현황을 확인하고 eLoran 전국망 지상기반 PNT 서비스의 안정 제공을 위한 울릉도, 제주도 신규송신국 구축 가능한 해수부 부지를 사전 검토하고 부지 특성에 따른 안테나 설계 적합성 및 성능을 검토하여 적정한 안테나 배치안을 제시하였다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.171-180
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• 2008

This paper also suggests the Digital Evidence Transmission System for E-Discovery which is suited to domestic environments in order to solve these problems and promote safe and convenient transmission of the electronic evidences. The suggested Digital Evidence Transmission System for E-Discovery is the system that submit digital evidences to Court's Sever through the Internet using Public Key Infrastructure and Virtual Private Network, and solves the problems - such as privileged and privacy data, trade secret of company, etc.