Suchergebnisse

In our study, we explore the COVID‐19 dynamics to test whether the virus has reached its equilibrium point and to identify the main factors explaining the current R and case fatality rate (CFR) variability across countries. We present a retrospective study of publicly available country‐level data from 50 countries having the highest number of confirmed COVID–19 cases at the end of September 2021. The mean values of country‐level moving averages of R and CFR went down respectively from 1.118 and 6.3% on June 30, 2020 to 1.083 and 3.6% on September 30, 2020 and to 1.015 and 1.8% by September 30, 2021. In parallel, the 10%–90% inter‐percentile range of R and CFR moving averages decreased, respectively, from 0.288 and 13.3% on June 30, 2020, to 0.151 and 7.7% on September 30, 2020, and to 0.107 and 3.3% by September 30, 2021. The slow decrease in the country‐level moving averages of R, approaching the level of 1.0 and accompanied by repeated outbreaks ("waves") in various countries, may indicate that COVID‐19 has reached its point of stable endemic equilibrium. A regression analysis implies that only a prohibitively high level of herd immunity (about 63%) may stop the endemic by reaching a stable disease‐free equilibrium. It also appears that fully vaccinating about 70% of a country's population should be sufficient for bringing the CFR close to the level of the seasonal flu (about 0.1%). Thus, while the currently available vaccines prove to be effective in reducing the mortality from the existing COVID‐19 variants, they are unlikely to stop the spread of the virus in the foreseeable future. It is noteworthy that government measures restricting people's behavior (such as lockdowns) were not found to have statistically significant effects in the analyzed data.

The first case of COVID-19 was confirmed in Israel on February 21, 2020. Within approximately 30 days, the total number of confirmed cases climbed up to 1, 000, accompanied by a doubling period of less than 3 days. About one week later, after this number exceeded 4, 000 cases, and following some extreme lockdown measures taken by the Israeli government, the daily infection rate started a sharp decrease from the peak value of 1, 131 down to slightly more than 100 new confirmed cases on April 30. Motivated by this encouraging data, similar to the trends observed in many other countries, along with the growing economic pressures, the Israeli government has quickly lifted most of its emergency regulations. Throughout May, the daily number of new cases stayed at a very low level of 20–40 until at the end of May it started a steady increase, exceeding 1, 000 by the end of June and 2, 000 on July 22. As suggested by some experts and popular media, this disturbing trend may be even a part of a "second wave". This article attempts to analyze the data available on Israel at the end of July 2020, compared to three European countries (Greece, Italy, and Sweden), in order to understand the local dynamics of COVID-19, assess the effect of the implemented intervention measures, and discuss some plausible scenarios for the foreseeable future.

Terrorists are continuously learning to utilize the Internet as an accessible and cost-effective information infrastructure. Since a constant manual monitoring of terrorist-generated multilingual web content is not a feasible task, automated Web Intelligence and Web Mining methods are indispensable for efficiently securing the Web against its misuse by terrorists and other dangerous criminals. Web Intelligence and Security contains chapters by the key speakers of the NATO Advanced Research Workshop on Web Intelligence and Security that took place on November 18-20, 2009 in Ein-Bokek, Israel. This Workshop has brought together a multinational group of leading scientists and practitioners interested in exploiting data and text mining techniques for countering terrorist activities on the Web. Most talks were focused on presenting available methods and tools that can alleviate the information overload of intelligence and security experts. The key features of this book include: An up-to-date analysis of the current and future threats of the Internet misuse by terrorists and other malicious elements including cyberterrorism, terror financing and interactive online communication by terrorists and their supporters; Detailed presentation of the state-of-the-art algorithms and tools aimed at detecting and monitoring malicious online activities on the Web; Introduction of novel data mining and text mining methods that can be used to efficiently analyze the massive amounts of multi-lingual Web content; The book's wide audience includes research scientists, graduate students, intelligence analysts, and data / text mining practitioners.

1. Terrorism and the internet : use and abuse / Abraham R. Wagner -- 2. The radical Islam and the cyber Jihad / Shaul Shay -- 3. Using data mining technology for terrorist detection on the web / Mark Last -- 4. A content-based model for web-monitoring / Bracha Shapira -- 5. TDS - an innovative terrorist detection system / Yuval Elovici -- 6. Clustering algorithms for variable-length vectors and their application to detecting terrorist activities / Menahem Friedman, Moti Schneider, Abraham Kandel -- 7. Analysis of financial intelligence and the detection of terror financing / Yehuda Shaffer -- 8. Identification of terrorist web sites with cross-lingual classification tools / Alex Markov and Mark Last.