Blockchain, which is the underlying technology of the first cryptocurrency Bitcoin, has drawn a lot of global attention in recent years. Its notable characteristics of the distributed ledger, trustless system, and immutability not only makes it a disruptive innovation in the electronic payment industry but also potential solutions for other areas that require trust establishment. Electronic voting (E-voting) scheme is a use-case where all attributes of blockchain can offer a mechanism for an open, fair and universally verifiable electoral process. In this paper, we review the requirements and then propose Votereum, an E-voting system that utilizes the blockchain technology. The proposed system is empowered by Ethereum platform, including one server manages the entire system and the other handles all blockchain-related requests. The implementation is also deployed to Rinkeby testing network for evaluation on the feasibility and discussion on some security concerns, which are mentioned in the conclusion of this paper.

The COVID-19 pandemic, since its beginning in December 2019, has altered every aspect of human life. In Vietnam, the pandemic is in its fourth peak and is the most serious so far, putting Vietnam in the list of top 30 countries with the highest daily cases. In this paper, we wish to identify the magnitude of its impact on college students in Vietnam. As far as we’re concerned, college students belong to the most affected groups in the population, especially in big cities that have been hitting hard by the virus. We conducted an online survey from 31 May 2021 to 9 June 2021, asking students from four representative regions in Vietnam to describe how the pandemic has changed their lifestyle and studying environment, as well as their awareness, compliance, and psychological state. The collected answers were processed to eliminate unreliable ones then prepared for sentiment analysis. To analyze the relationship among the variables, we performed a variety of statistical tests, including Shapiro–Wilk, Mc Nemar, Mann–Whitney–Wilcoxon, Kruskal–Wallis, and Pearson’s Chi-square tests. Among 1875 students who participated, many did not embrace online education. A total of 64.53% of them refused to think that online education would be the upcoming trend. During the pandemic, nearly one quarter of students were in a negative mood. About the same number showed signs of depression. We also observed that there were increasing patterns in sleeping time, body weight, and sedentary lifestyle. However, they maintained a positive attitude toward health protection and compliance with government regulations (65.81%). As far as we know, this is the first project to conduct such a large-scale survey analysis on students in Vietnam. The findings of the paper help us take notice of financial and mental needs and perspective issues for indigent students, which contributes to reducing the pandemic’s negative effects and going forwards to a better and more sustainable life.

There is increasing interest in context-aware applications, ranging from traffic routing, location-based services, friend finding, context-aware messaging, virtual tour guides, to physical world search. We make three observations: (i) many context-aw