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Aiming at the problem that KCF tracking algorithm might decrease the tracking performance or even tracks unsuccessfully in the occlusion scene, an anti-occlusion model adaptation image tracking algorithm was pro posed by combining KCF and KF prediction. Firstly, considering the lack of occlusion evaluation in the traditional KCF target tracking algorithm, the peak sidelobe rate of the response map was introduced to judge the occlusion of the image target, and the occlusion types were divided into partial occlusion and severe occlusion. Then different model update strategies were adopted according to the severity of occlusion. When the target was not occluded or occluded partially, instead of using a fixed learning rate to update the model in the traditional KCF tracking algorithm, the target appearance model was updated by adjusting the model learning rate adaptively to avoid tracking drift. When the target was severely occluded, stopped updating the KCF model. Finally, the state space and position output models of Kalman filter were constructed by applying the motion information before severe occlusion. The Kalman filter prediction algorithm was designed to predict the moving target trajectory and estimate the target position in the occlusion scene, so as to solve the problem of target tracking failure in occlusion scenes. The OTB2013 standard dataset was utilized to conduct extensive experiments, the results demonstrated that the distance accuracy of the proposed hybrid tracking algorithm KCF-KF was 0.796, and the overlap success rate was 0.692. Compared with the other traditional tracking algorithms, the tracking accuracy and success rate of the hybrid algorithm were better, and the hybrid algorithm could achieve better tracking performance when encountering the target occlusion challenges and solve the occlusion interference in the tracking process effectively. [ABSTRACT FROM AUTHOR]

To solve the difficult tradeoff between security requirements and resource cost in radio frequency identification (RFID) triple authentication protocol, a PUF-based high-security lightweight RFID triple authentication protocol (PHL-RTAP) was proposed. Physical unclonable function (PUF) was utilized to authenticate the tag identity for protecting the tag from physical cloning attacks and reducing the tag cost, meeting the demand of resource-constrained RFID system. The quadratic residual algorithm was adopted to secure the reader data privacy. Random numbers were introduced to resist replay attacks and ensure the anonymity and untraceability of tags and readers. The PHL-RTAP could realize a complete triple authentication between server, reader and tag, and expand the scale of readers and tags in RFID systems according to different requirements, so that it was suitable for large-scale tag RFID system. Security analysis showed that PHL-RTAP could effectively resist various malicious attacks such as tracking attacks, replay attacks, physical cloning attacks and desynchronization attacks. BAN logic analysis and AVISPA tool were used to verify the security of the protocol. Compared with recent protocols, PHL-RTAP could make up for the security defects of similar RFID protocols, and has low resource costs such as computing cost, tag storage cost, and communication cost. PHL-RTAP could achieve both high security and lightweight, and was suitable for resource-constrained RFID triple authentication scenarios. [ABSTRACT FROM AUTHOR]

Grain boundary diffusion (GBD) of multiple rare earths has proven effective in enhancing the performance of permanent magnets, whereas the diffusion behaviors are still unclear due to their intricate interactions. In this work, the synergistic effects of three rare earths (Tb, Ce, and La) on the grain boundaries diffusion process are investigated, achieving a high‐performance diffused Nd–Fe–B magnet with the high coercivity of 1822 kA m−1 and thermal stability of −0.447% K−1. This promotion originates from the improved diffusion depth of Tb at specific regions, induced by the coordination effects of Ce and La, as evidenced via electron probe microanalysis and the first‐principles calculations. It thus results in the uniform formation of Tb‐diffused magnetic harden grains, associated with the strongly pinned domain walls, which is further observed directly by in situ Lorentz transmission electron microscopy and reconstructed by micromagnetic simulations. The study provides insight into the role of element GBD mechanism and has promising potential to explore other element systems as diffusion sources for permanent magnets. [ABSTRACT FROM AUTHOR]