A novel infectious respiratory disease was recognized in Wuhan (Hubei Province, China) in December 2019. In February 2020, the disease was named “coronavirus disease 2019” (COVID-19). COVID-19 became a pandemic in March 2020, and, since then, different countries have implemented a broad spectrum of policies. Thailand is considered to be among the top countries in handling its first wave of the outbreak—12 January to 31 July 2020. Here, we illustrate how Thailand tackled the COVID-19 outbreak, particularly the effects of public health interventions on the epidemiological spread. This study shows how the available data from the outbreak can be analyzed and visualized to quantify the severity of the outbreak, the effectiveness of the interventions, and the level of risk of allowed activities during an easing of a “lockdown.” This study shows how a well-organized governmental apparatus can overcome the havoc caused by a pandemic.

We present the first comprehensive characterization of the diffusion of ideas on Twitter, studying more than 5.96 million topics that include both popular and less popular topics. On a data set containing approximately 10 million users and a comprehensive scraping of 196 million tweets, we perform a rigorous temporal and spatial analysis, investigating the time-evolving properties of the subgraphs formed by the users discussing each topic. We focus on two different notions of the spatial: the network topology formed by follower-following links on Twitter, and the geospatial location of the users. We investigate the effect of initiators on the popularity of topics and find that users with a high number of followers have a strong impact on topic popularity. We deduce that topics become popular when disjoint clusters of users discussing them begin to merge and form one giant component that grows to cover a significant fraction of the network. Our geospatial analysis shows that highly popular topics are those that cross regional boundaries aggressively.

Content Delivery Networks (CDNs) are commonly believed to offer their customers protection against application-level denial of service (DoS) attacks. Indeed, a typical CDN with its vast resources can absorb these attacks without noticeable effect. This paper uncovers a vulnerability which not only allows an attacker to penetrate CDN's protection, but to actually use a content delivery network to amplify the attack against a customer Web site. We show that leading commercial CDNs -Akamai and Limelight -and an influential research CDN -Coral -can be recruited for this attack. By mounting an attack against our own Web site, we demonstrate an order of magnitude attack amplification though leveraging the Coral CDN. We present measures that both content providers and CDNs can take to defend against our attack. We believe it is important that CDN operators and their customers be aware of this attack so that they could protect themselves accordingly.

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