• Journal of radiological science and technology
• /
• v.43 no.6
• /
• pp.511-518
• /
• 2020

In the pandemic situation due to corona 19, we examined the satisfactory level of students' between non-face-to-face and online classes in the first year of radiology. In the case of online non-face classes related to radiation majors, it is considered better to conduct real-time lectures than recorded lectures, which allows students to understand difficult radiation majors throughout real-time questions and answers, and at the same time allows them to sympathize with difficult subjects such as intimacy and bonds between students. As a result of the analysis of the answers to questionnaires, the coefficient of answer correlation between first and second grade students is P>0.05, and there is no answer correlation between grades, and it can be seen that the higher the grade, the higher the demand for face-to-face classes was.

• Journal of Internet of Things and Convergence
• /
• v.6 no.4
• /
• pp.1-6
• /
• 2020

Recently, epidemic of covid-19 causes rapid increase in demand for untact video conferences. In existing server-client based video conference systems such as Zoom, Google Meet, etc., the server generates the conference key and controls the access rights of meeting members and their contents with it. In this case, the server can fabricate or repudiate the meeting. So, the privacy of the meeting members is not guaranteed. It's necessary to make the conference key distribution scheme where all participants can verify the trustfulness without help of the server. The smart contract is the program stored to the blockchain. Its contents cannot be altered due to the property of the blockchain, and everybody can verify the execution results of it. In this study, we propose the smart contract based conference key distribution scheme. The proposed scheme is consisted of smart contract deployment, conference key generation and verification stages. The smart contract replaces the role of existing trustful server and the meeting members can generate the conference key according to the protocols implemented on it. The proposed scheme can be applied to the video conference systems and only the meeting members can access the conference key.