In recent years, radio frequency identification (RFID) technology has been applied in various fields to efficiently identify objects. Considering that identification is usually performed continuously, the latest RFID approaches use previous identification results for subsequent identifications and can identify two tags per unit time. However, these approaches have not utilized bit-level collision information in ID transmissions, which can facilitate the identification. Moreover, the assumption of reliable communication is not always valid in real-world applications. In this article, we propose a new approach called the multiple resolution bit tracking (MRB) to further improve the identification performance. This approach dynamically computes a tag set that can be unambiguously identified irrespective of any missing subset. These tags are requested to transmit their IDs in the same timeslot. Strategies to handle unreliable communication have also been proposed and optimized for MRB. We performed extensive simulations to validate the performance of our proposed approach. The results show that MRB can achieve 3.7 tags per unit time, which is 1.85 times the number achieved using the existing approaches. Furthermore, MRB handles unreliable communications well and achieves a small given tag missing rate.

Combining the latest biological results of behavior of intensive flight of starlings, this paper presents topological formation structure and an improved particle swarm algorithm based on the flight mechanism of starlings and its application to the formation of UAV cluster. It also proposes an approach of controling formation behavior of UAVs based on the improved artificial potential fields method. Through simulation experiments, the comparative results are given for verifying the efficiency of formation missions of our methods, as well as simulation of cluster behavior of aggregation and dispersion. The results provide technical assistance for simulation of autonomous collaborative formation of large-scale UAV cluster.

It is becoming more and more important to make analysis on activity regularity of population in urban commercial districts, which would be beneficial to commercial infrastructure distribution and construction. The paper presents an approach to mining