Over time, the world has transformed digitally and there is total dependence on the internet. Many more gadgets are continuously interconnected in the internet ecosystem. This fact has made the Internet a global infor...Over time, the world has transformed digitally and there is total dependence on the internet. Many more gadgets are continuously interconnected in the internet ecosystem. This fact has made the Internet a global information source for every being. Despite all this, attacker knowledge by cybercriminals has advanced and resulted in different attack methodologies on the internet and its data stores. This paper will discuss the origin and significance of Denial of Service (DoS) and Distributed Denial of Service (DDoS). These kinds of attacks remain the most effective methods used by the bad guys to cause substantial damage in terms of operational, reputational, and financial damage to organizations globally. These kinds of attacks have hindered network performance and availability. The victim’s network is flooded with massive illegal traffic hence, denying genuine traffic from passing through for authorized users. The paper will explore detection mechanisms, and mitigation techniques for this network threat.展开更多
The SO4^（2-）concentration distributions in surface region of cement mortar immersed in sulfate solution at early stage were measured by layered sampling method combined with chemical analysis, and the diffusion coef...The SO4^（2-）concentration distributions in surface region of cement mortar immersed in sulfate solution at early stage were measured by layered sampling method combined with chemical analysis, and the diffusion coefficients of SO4^（2-）anions in surface region of mortar into internal area were calculated by means of instantaneous plane diffusion theory. The experimental results showed that the SO4^（2-）concentration gradually reduced when the diffusion depth increased in the surface region of mortar. Diffusion coefficient（D） was relevant with the concentration and kind of environmental sulfate solution, which reduced with immersion time at the beginning, and then rose slowly after a period of time. The calculation of initial diffusion coefficient（D0） and starting time of deterioration（t∞） caused by sulfate attack was further attempted based on the data of diffusion coefficient, and it was found that D0 and t∞ were all relevant with concentrations of sulfate and different kind of sulfate as well.展开更多
文摘Over time, the world has transformed digitally and there is total dependence on the internet. Many more gadgets are continuously interconnected in the internet ecosystem. This fact has made the Internet a global information source for every being. Despite all this, attacker knowledge by cybercriminals has advanced and resulted in different attack methodologies on the internet and its data stores. This paper will discuss the origin and significance of Denial of Service (DoS) and Distributed Denial of Service (DDoS). These kinds of attacks remain the most effective methods used by the bad guys to cause substantial damage in terms of operational, reputational, and financial damage to organizations globally. These kinds of attacks have hindered network performance and availability. The victim’s network is flooded with massive illegal traffic hence, denying genuine traffic from passing through for authorized users. The paper will explore detection mechanisms, and mitigation techniques for this network threat.
基金Funded by the Major State Basic Research Development Program of China(No.2011CB013800)
文摘The SO4^（2-）concentration distributions in surface region of cement mortar immersed in sulfate solution at early stage were measured by layered sampling method combined with chemical analysis, and the diffusion coefficients of SO4^（2-）anions in surface region of mortar into internal area were calculated by means of instantaneous plane diffusion theory. The experimental results showed that the SO4^（2-）concentration gradually reduced when the diffusion depth increased in the surface region of mortar. Diffusion coefficient（D） was relevant with the concentration and kind of environmental sulfate solution, which reduced with immersion time at the beginning, and then rose slowly after a period of time. The calculation of initial diffusion coefficient（D0） and starting time of deterioration（t∞） caused by sulfate attack was further attempted based on the data of diffusion coefficient, and it was found that D0 and t∞ were all relevant with concentrations of sulfate and different kind of sulfate as well.
