• Journal of Korea Society of Industrial Information Systems
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• v.17 no.7
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• pp.51-57
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• 2012

This paper proposes a group key design based on ECDH(Elliptic Curve Diffie Hellman) which guarantees secure V2V and V2I communication. The group key based on ECDH generates the VGK(Vehicular Group key) which is a group key between vehicles, the GGK(Global Group Key) which is a group key between vehicle groups, and the VRGK(Vehicular and RSU Group key) which is a group key between vehicle and RSUs with ECDH algorithm without an AAA server being used. As the VRGK encrypted with RGK(RSU Group Key) is transferred from the current RSU to the next RSU through a secure channel, a perfect forward secret security is provided. In addition, a Sybil attack is detected by checking whether the vehicular that transferred a message is a member of the group with a group key. And the transmission time of messages and the overhead of a server can be reduced because an unnecessary network traffic doesn't happen by means of the secure communication between groups.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.4
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• pp.186-194
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• 2018

A ground-source heat pump system (GSHP) is more energy efficient than other heat-source systems because it uses annual constant underground and water temperatures. Especially, two-well geothermal systems using groundwater as the heat source can achieve higher performance than closed-loop geothermal systems. However, performance of two-well geothermal systems is decreased by occurring overflow according to scale during long-term operations. Therefore, this study presents a two-well pairing geothermal system that controls the groundwater level of a diffusion well. In addition, a two-well pairing geothermal system and an SCW geothermal system were installed, and a comparative analysis of cooling performance depending on system operation under the same load conditions was conducted. The result was that the average heat pump coefficient of performance (COP) of the two-well pairing system was 6.5, and the entire system COP was 4.3.

• The Journal of Korean Academic Society of Nursing Education
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• v.29 no.4
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• pp.415-428
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• 2023

Purpose: The purpose of this study is to better understand nursing education in the early years of the Japanese colonial rule. Methods: We compared the 1918 Textbook on Nursing with the first Textbook on Nursing and to the original text, Grade A Textbook on Nursing, by the Japanese Red Cross Society (JRCS) using the historical research method. The background of its publication and its use in nursing education were exploring, too. Results: After Korea's annexation by Japan, the nursing textbook by the JRCS was appointed as the standard textbook in nursing education by the Government-General in Korea (GGK). Missionary nurse got the permission for the nursing textbook by JRCS and the Textbook on Nursing was published in 1918 using Korean and Chinese characters in combination. This book, an adaptation of the original text, explained the responsibilities and roles of nurses to guide them in serving patients as well as assisting in treatment or directly performing emergency medical treatment when necessary, with a focus on the treatment of the war wounded. It would have been partially used in actual nursing education among the missionary community. Conclusion: Textbook on Nursing in 1918 was published not only for the nursing students of missionary nursing schools but also for other nursing trainees of diverse hospitals, nurses and missionary volunteers and to help them to acquire the licenses. It reflects the enforcement on nursing education by GGK and the reality and resistance in terms of the content of education of nursing in Korea during that period.