无线射频识别(radio frequency identification,RFID)系统中的标签识别速率直接决定了系统性能,设计一个高效的标签防碰撞方法能够有效提升读写器的识别效率,并降低读写器和标签所消耗的能量.在分析已有的两类防碰撞算法性能的基础上,...无线射频识别(radio frequency identification,RFID)系统中的标签识别速率直接决定了系统性能,设计一个高效的标签防碰撞方法能够有效提升读写器的识别效率,并降低读写器和标签所消耗的能量.在分析已有的两类防碰撞算法性能的基础上,提出了一类融合帧时隙ALOHA思想与二进制树思想的新型防碰撞算法.4种新型算法在算法性能上稳步提升,系统能量消耗也呈递减趋势,特别适合手持式电池供能的读写器.仿真结果表明,自适应帧的二进制防碰撞算法(SA-FBS)在减少碰撞时隙上明显优于传统的防碰撞算法.展开更多
The diffusion layers in substitution-permutation network（SPN） block ciphers are almost invertible linear transformations, which is optimal if the branch number reaches the maximum value. The method of constructing i...The diffusion layers in substitution-permutation network（SPN） block ciphers are almost invertible linear transformations, which is optimal if the branch number reaches the maximum value. The method of constructing involutory optimal diffusion layers is proposed based on the Cauchy matrix, which can decrease the cost of implementation. The analysis to experimental results indicates that the diffusion layer ensures the security of the SPN block cipher against differential cryptanalysis（DC） and linear cryptanalysis（LC）, and decreases half the cost of implementation.展开更多
The sensor virus is a serious threat,as an attacker can simply send a single packet to compromise the entire sensor network.Epidemics become drastic with link additions among sensors when the small world phenomena occ...The sensor virus is a serious threat,as an attacker can simply send a single packet to compromise the entire sensor network.Epidemics become drastic with link additions among sensors when the small world phenomena occur.Two immunization strategies,uniform immunization and temporary immunization,are conducted on small worlds of tree-based wireless sensor networks to combat the sensor viruses.With the former strategy,the infection extends exponentially,although the immunization effectively reduces the contagion speed.With the latter strategy,recurrent contagion oscillations occur in the small world when the spatial-temporal dynamics of the epidemic are considered.The oscillations come from the small-world structure and the temporary immunization.Mathematical analyses on the small world of the Cayley tree are presented to reveal the epidemic dynamics with the two immunization strategies.展开更多
文摘无线射频识别(radio frequency identification,RFID)系统中的标签识别速率直接决定了系统性能,设计一个高效的标签防碰撞方法能够有效提升读写器的识别效率,并降低读写器和标签所消耗的能量.在分析已有的两类防碰撞算法性能的基础上,提出了一类融合帧时隙ALOHA思想与二进制树思想的新型防碰撞算法.4种新型算法在算法性能上稳步提升,系统能量消耗也呈递减趋势,特别适合手持式电池供能的读写器.仿真结果表明,自适应帧的二进制防碰撞算法(SA-FBS)在减少碰撞时隙上明显优于传统的防碰撞算法.
文摘The diffusion layers in substitution-permutation network（SPN） block ciphers are almost invertible linear transformations, which is optimal if the branch number reaches the maximum value. The method of constructing involutory optimal diffusion layers is proposed based on the Cauchy matrix, which can decrease the cost of implementation. The analysis to experimental results indicates that the diffusion layer ensures the security of the SPN block cipher against differential cryptanalysis（DC） and linear cryptanalysis（LC）, and decreases half the cost of implementation.
文摘The sensor virus is a serious threat,as an attacker can simply send a single packet to compromise the entire sensor network.Epidemics become drastic with link additions among sensors when the small world phenomena occur.Two immunization strategies,uniform immunization and temporary immunization,are conducted on small worlds of tree-based wireless sensor networks to combat the sensor viruses.With the former strategy,the infection extends exponentially,although the immunization effectively reduces the contagion speed.With the latter strategy,recurrent contagion oscillations occur in the small world when the spatial-temporal dynamics of the epidemic are considered.The oscillations come from the small-world structure and the temporary immunization.Mathematical analyses on the small world of the Cayley tree are presented to reveal the epidemic dynamics with the two immunization strategies.
