随着物联网的成熟发展,无线射频识别技术(Radio Frequency Identification, RFID)在物联网相关技术中扮演着至关重要的角色。在万物互联的时代,对RFID技术的应用日益广泛,针对该技术的研究也逐渐受到学者们的广泛关注。然而RFID技术在...随着物联网的成熟发展,无线射频识别技术(Radio Frequency Identification, RFID)在物联网相关技术中扮演着至关重要的角色。在万物互联的时代,对RFID技术的应用日益广泛,针对该技术的研究也逐渐受到学者们的广泛关注。然而RFID技术在系统应用的过程中,仍面临了种类繁多的安全隐患,因此,本文对RFID技术面临的安全隐患进行了概述与分析,对未来RFID技术的发展有着重要意义。首先,本文总结了应对RFID技术各类隐患的RFID技术安全方案,主要分为物理安全方案和密码学相关方案。其次,分析了现有结合了密码学相关方案的RFID技术的认证协议。最后,对RFID技术的应用前景与发展趋势进行了总结展望。展开更多
Facing the problems lack of considering the non-uniform distribution of the static bias magnetic field and computing the panicle displacements in the simulation model of electromagnetic acoustic transducer （EMAT）, a...Facing the problems lack of considering the non-uniform distribution of the static bias magnetic field and computing the panicle displacements in the simulation model of electromagnetic acoustic transducer （EMAT）, a multi-field coupled model was established and the finite element method （FEM） was presented to calculate the entire transduction process. The multi-field coupled model included the static magnetic field, pulsed eddy current field and mechanical field. The FEM equations of the three fields were derived by Garlerkin FEM method. Thus, the entire transduction process of the EMAT was calculated through sequentially coupling the three fields. The transduction process of a Lamb wave EMAT was calculated according to the present model and method. The results show that, by the present method, it is valid to calculate the particle displacement under the given excitation signal and non-uniformly distributed static magnetic field. Calculation error will be brought about if the non-uniform distribution of the static bias magnetic field is neglected.展开更多
文摘随着物联网的成熟发展,无线射频识别技术(Radio Frequency Identification, RFID)在物联网相关技术中扮演着至关重要的角色。在万物互联的时代,对RFID技术的应用日益广泛,针对该技术的研究也逐渐受到学者们的广泛关注。然而RFID技术在系统应用的过程中,仍面临了种类繁多的安全隐患,因此,本文对RFID技术面临的安全隐患进行了概述与分析,对未来RFID技术的发展有着重要意义。首先,本文总结了应对RFID技术各类隐患的RFID技术安全方案,主要分为物理安全方案和密码学相关方案。其次,分析了现有结合了密码学相关方案的RFID技术的认证协议。最后,对RFID技术的应用前景与发展趋势进行了总结展望。
基金Project(10974115) supported by the National Natural Science Foundation of China
文摘Facing the problems lack of considering the non-uniform distribution of the static bias magnetic field and computing the panicle displacements in the simulation model of electromagnetic acoustic transducer （EMAT）, a multi-field coupled model was established and the finite element method （FEM） was presented to calculate the entire transduction process. The multi-field coupled model included the static magnetic field, pulsed eddy current field and mechanical field. The FEM equations of the three fields were derived by Garlerkin FEM method. Thus, the entire transduction process of the EMAT was calculated through sequentially coupling the three fields. The transduction process of a Lamb wave EMAT was calculated according to the present model and method. The results show that, by the present method, it is valid to calculate the particle displacement under the given excitation signal and non-uniformly distributed static magnetic field. Calculation error will be brought about if the non-uniform distribution of the static bias magnetic field is neglected.
