Universal Web Application Server

The growth of the World Wide Web has in large part been made possible by the technologies that power it. These are the Web servers and Web browsers that many take for granted. Each has evolved to support the changing needs of users of the WWW from simple static text to highly interactive and dynamic multimedia. The Web servers, in particular, have evolved into a spectrum of different technologies to support what are now known as Web applications. These are usually installed and accessed through a Web server. Security is a problem in Web server environments and therefore the Web servers are usually run as an un-privileged user. Performance is another problem as some of these technologies require re-initialization of the execution environment with every subsequent request. These security and performance shortcomings have been dealt with by numerous Web application technologies. Most of these technologies are language-centric and seek solutions to the security and performance shortcomings independently of each other. The universal Web application server is proposed as an alternative solution addressing the security, language dependence and performance shortcomings of existing technologies. It has support for multiple authors in a secure environment with support for multiple implementation technologies (languages) using persistent interpreters to enhance performance. Test results from the performance evaluation show that the introduction of the layers of processing contributes a small percentage to the total request processing time and that the universal Web application server can perform comparably to other Web application servers. Tests with twenty users also showed that packaging and deploying Web applications in the universal Web application server is an easy and viable approach. Moreover, the installation of PhpBB2 in the universal Web application server demonstrates that it can be used with realistic Web applications. A universal Web application server that provides an efficient, secure and language independent environment has been developed and thoroughly evaluated demonstrating that a Web application server that addresses the shortcomings of existing technologies is feasible

X-Switch: A Secure, Multi-User, Language-Independent Web Application Server

The need for user interactivity has led to the creation of many technologies for Web applications. These Web applications are usually installed on and accessed through a Web application server. Security is however a problem in such environments and most of the servers and Web applications are thus run as the restricted user ‘nobody’. Performance also is an issue due to process re-initialisation. Many technologies resolve some security and performance shortcomings in limited contexts. This paper presents the X-Switch system: a secure language independent Web application server that is a generalisation of existing technologies. Experimental results show that the X-Switch system can perform comparably to other Web application servers and that a general solution is possible

X-Switch: An Efficient, Multi-User, Multi-Language Web Application Server

Web applications are usually installed on and accessed through a Web server. For security reasons, these Web servers generally provide very few privileges to Web applications, defaulting to executing them in the realm of a guest account. In addition, performance often is a problem as Web applications may need to be reinitialised with each access. Various solutions have been designed to address these security and performance issues, mostly independently of one another, but most have been language or system-specic. The X-Switch system is proposed as an alternative Web application execution environment, with more secure user-based resource management, persistent application interpreters and support for arbitrary languages/interpreters. Thus it provides a general-purpose environment for developing and deploying Web applications. The X-Switch system's experimental results demonstrated that it can achieve a high level of performance. Furthermore it was shown that X-Switch can provide functionality matching that of existing Web application servers but with the added benefit of multi-user support. Finally the X-Switch system showed that it is feasible to completely separate the deployment platform from the application code, thus ensuring that the developer does not need to modify his/her code to make it compatible with the deployment platform

Estimating the Lineage Dynamics of Human Influenza B Viruses

The prediction of the lineage dynamics of influenza B viruses for the next season is one of the largest obstacles for constructing an appropriate influenza trivalent vaccine. Seasonal fluctuation of transmissibility and epidemiological interference between the two major influenza B lineages make the lineage dynamics complicated. Here we construct a parsimonious model describing the lineage dynamics while taking into account seasonal fluctuation of transmissibility and epidemiological interference. Using this model we estimated the epidemiological and evolutional parameters with the time-series data of the lineage specific isolates in Japan from the 2010-2011 season to the 2014-2015 season. The basic reproduction number is similar between Victoria and Yamagata, with a minimum value during one year as 0.82 (95% highest posterior density (HPD): 0.77-0.87) for the Yamagata and 0.83 (95% HPD: 0.74-0.92) for Victoria, the amplitude of seasonal variation of the basic reproduction number is 0.77 (95% HPD: 0.66-0.87) for Yamagata and 1.05 (95% HPD: 0.89-1.02) for Victoria. The duration for which the acquired immunity is effective against infection by the Yamagata lineage is shorter than the acquired immunity for Victoria, 424.1days (95% HPD: 317.4-561.5days). The reduction rate of susceptibility due to immune cross-reaction is 0.51 (95% HPD: 0.084-0.92) for the immunity obtained from the infection with Yamagata against the infection with Victoria and 0.62 (95% HPD: 0.42-0.80) for the immunity obtained from the infection with Victoria against the infection with Yamagata. Using estimated parameters, we predicted the dominant lineage in 2015-2016 season. The accuracy of this prediction is 68.8% if the emergence timings of the two lineages are known and 61.4% if the emergence timings are unknown. Estimated seasonal variation of the lineage specific reproduction number can narrow down the range of emergence timing, with an accuracy of 64.6% if the emergence times are assumed to be the time at which the estimated reproduction number exceeds one

X-Switch: An Efficient Multi-User Multi-Language Web Application Server.

Web applications are usually installed on and accessed through a Web server. For security reasons, these Web servers generally provide very few privileges to Web applications, defaulting to executing them in the realm of a guest account. In addition, performance often is a problem as Web applications may need to be reinitialised with each access. Various solutions have been designed to address these security and performance issues, mostly independently of one another, but most have been language or system-specific. The X-Switch system is proposed as an alternative Web application execution environment, with more secure user-based resource management, persistent application interpreters and support for arbitrary languages/interpreters. Thus it provides a general-purpose environment for developing and deploying Web applications. The X-Switch system’s experimental results demonstrated that it can achieve a high level of performance. Furthermore it was shown that X-Switch can provide functionality matching that of existing Web application servers but with the added benefit of multi-user support. Finally the X-Switch system showed that it is feasible to completely separate the deployment platform from the application code, thus ensuring that the developer does not need to modify his/her code to make it compatible with the deployment platform

The posterior of parameters estimated using the data in varied seasons.

<p>Each parenthesis shows the 95% highest posterior density.</p