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The rise in phishing attacks via e-mail and short message service (SMS) has not slowed down at all. The first thing we need to do to combat the ever-increasing number of phishing attacks is to collect and characterize more phishing cases that reach end users. Without understanding these characteristics, anti-phishing countermeasures cannot evolve. In this study, we propose an approach using Twitter as a new observation point to immediately collect and characterize phishing cases via e-mail and SMS that evade countermeasures and reach users. Specifically, we propose CrowdCanary, a system capable of structurally and accurately extracting phishing information (e.g., URLs and domains) from tweets about phishing by users who have actually discovered or encountered it. In our three months of live operation, CrowdCanary identified 35,432 phishing URLs out of 38,935 phishing reports. We confirmed that 31,960 (90.2%) of these phishing URLs were later detected by the anti-virus engine, demonstrating that CrowdCanary is superior to existing systems in both accuracy and volume of threat extraction. We also analyzed users who shared phishing threats by utilizing the extracted phishing URLs and categorized them into two distinct groups -namely, experts and non-experts. As a result, we found that CrowdCanary could collect information that is specifically included in non-expert reports, such as information shared only by the company brand name in the tweet, information about phishing attacks that we find only in the image of the tweet, and information about the landing page before the redirect.

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In the seismic design of the boiling water reactor, we need to estimate the dynamic insertion behavior of control rods into the core region to secure the safety of the reactor under seismic events. In particular, estimation of the insertion time is one of the most important design tasks affecting the scrammability of the reactor. We developed a numerical analysis model to predict the control rod insertion time under seismic events using multibody dynamics. The effect of the interaction force between the control rod and the fuel assemblies is considered in three-dimensional contact analysis. This interaction force causes resistance force acting on the control rod under insertion. The hydraulic control unit and the control rod drive, which provide the control rod with driving force, were modeled in the concentrated parameter system considering dynamic characteristics, such as the inertance of the working fluid in the scram piping and the capacitance of the working gas in the accumulator. The numerical analysis can simulate the realistic insertion behavior of the control rod by coupling these models together and using an interactive process to calculate how they interact. The validity of the numerical analysis model was confirmed by comparing the analytical results with the experimental ones. The results of our analysis showed that the numerical analysis model provides good agreement with the insertion time of the control rod.