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In this article, we discuss mobile source localization using both time of arrival and Doppler frequency shift (TOA-DFS) measurements, where the source moves at a nonuniform velocity. To obtain the position of a mobile source, we first formulate the weighted least-squares (WLS) problem by ignoring the second-order noise terms. Due to the nonconvexity, we apply the convex relaxation technique to transform the problem into a semidefinite programming (SDP) problem. However, ignoring the second-order noise terms is only reasonable in the case of small noise levels. In view of this, we then directly establish the maximum likelihood (ML) estimator based on the measurements model without ignoring the second-order noise terms. Since the ML estimator is a nonconvex problem, we also propose implementable semidefinite relaxation (SDR) technique to tackle it. Finally, the Cramér–Rao lower bound (CRLB) analysis and results verify that the proposed methods based on the TOA-DFS measurements can significantly enhance localization accuracy.

Flexible and foldable Li-ion batteries (LIBs) are presently attracting immense research interest for their potential use in wearable electronics but are still limited to electrodes with very small mass loading, low bending/folding endurance, and poor electrochemical stability during repeated bending and folding movements. Moreover, one-dimensional (1D) structured electrode materials have shown excellent electrochemical performance but are still restricted by the high cost and complicated fabrication process. Here, we present a very simple yet novel approach for fabricating extra-long Li4Ti5O12(LTO) and LiCoO2(LCO) nanofiber precursors by directly stirring the reagents in an atmospheric vessel. In addition, we present multilayer pyramid/inverted pyramid interlocking inside the LTO and LCO nanofiber films as well as between films and current collectors, which can create strengthened interfacial bonding like a zipper and tangentially disperse the strains generated during folding through the pyramidal planes and edges, leading to the realization of thick-film electrodes with outstanding electrochemical stability during folding movements. The foldable LIBs that are assembled with LTO and LCO nanofiber electrodes at a practical level of mass loading (14.9–19.4 mg cm–2) can maintain 102% of the initial capacity after 15 000 times of fully folding (180°) motions.

IEEE802.15.4e is the latest generation of high-reliability, low-power medium access control protocols. As part of IEEE802.15.4e, time synchronised channel hopping (TSCH) provides support for multi-hop and multi-channel communications. IEEE802.15.4e only defines when a schedule is executed; it does not specify a concrete resource schedule strategy. In this study, an IEEE802.15.4e TSCH scheduling algorithm called fair reliability scheduling algorithm (FRESA) is proposed to focus on both less delay and fair reliability. Through leaf node prior and multiple nodes sharing the same resource, there is less delay to transmit messages. Balancing the assignment of different qualities of channel offset guarantees fair reliability in message transmission. We design two strategies to ensure fair reliability, one based on per Link and the other based on per Path, and then accordingly divide our algorithm into FRESA-L and FRESA-P. Simulation results demonstrate our algorithm's performance. We also observe that FRESA-P can achieve higher reliability than FRESA-L.