The accurate state of charge (SoC) online estimation is a significant indicator that relates to driving ranges of electric vehicles (EV). The relationship between open circuit voltage (OCV) and SoC plays an important role in SoC estimation for lithium-ion batteries. To compare with the traditional incremental OCV (IO) test and the low current OCV (LO) test, a novel OCV test which combines IO test with LO test (CIL) is proposed in this paper. Based on the reliable parameters online identification of the dual polarization (DP) battery model, two SoC estimation algorithms are compared on the accuracy, robustness and convergence speed for the entire SoC region. Meanwhile, the comparative study of the three OCV-SoC relationships fits by the corresponding OCV tests is discussed in terms of the SoC online estimation under various temperatures. The results show that the adaptive extended Kalman filter (AEKF) algorithm can better improve the accuracy and robustness of SoC estimation than that of the extended Kalman filter (EKF) algorithm. Most importantly, the OCV-SoC relationship obtains from the CIL OCV test method is applied to the AEKF algorithm, which has higher accuracy and better statistical indices of SoC estimation, especially suitable for the low temperature. INDEX TERMS Lithium-ion batteries, state of charge estimation, open circuit voltage test, online parameters identification, adaptive extended Kalman filter algorithm.
Tympanic membrane (TM) perforation is a frequent cause of conductive hearing loss. The most popular surgical repair is autografting with temporalis fascia, although some disadvantages have been found with this method. Whether xenogeneous grafts produced by a tissue engineering approach could be used is unclear. The purpose of this study was to evaluate the possibility of bioengineering TM using porcine acellular dermis and dura mater with TM fibroblasts and to compare the effects of these two natural scaffolds. Both of the materials were prepared by sequentially using Triton X-100, nuclease solution, and freeze-drying technique. Histologically, both had porous structures without any cellular components. After seeding with TM fibroblasts isolated from guinea pigs, it was found that both of the materials could be used as scaffolds for bioengineering TM in vitro. In the in vivo study, chronic TM perforation models were successfully established in guinea pigs. From gross and histological examinations, most of TM perforations were healed after grafting these two bioengineered TMs using an underlay technique. Furthermore, auditory brainstem response audiometry was applied to determine the auditory threshold in each group. Results showed that hearing in the dura mater group seemed to undergo faster recovery in the early stage but in the end, no differences were found between the two groups. Two kinds of materials without cell seeding were used as controls. Porcine acellular dermis and dura mater are suitable scaffolds for bioengineering TMs.
The problem of transmission scheduling in single hop and multi-hop wireless networks has been extensively studied. The focus has been on optimizing the efficiency of transmission parallelization, through a minimum-length schedule that meets a given set of traffic demands using the smallest possible number of time slots. Each time slot is associated with a set of transmissions that are compatible with each other according to the considered interference model. The minimum-length approach maximizes the resource reuse, but it does not ensure minimum end-to-end packet delay for multiple source-destination pairs, due to its inherent assumption of frame periodicity. In the paper we study the problem of transmission scheduling and routing aiming at minimizing the endto-end delay under the signal-to-interference-and-noise-ratio (SINR) model for multi-hop networks. Two schemes are investigated. The first scheme departs from the conventional scheduling approach, by addressing explicitly end-to-end delay and removing the restriction of frame periodicity. The second scheme extends the first one by featuring cooperative forwarding and forward interference cancellation. We study the properties of the two schemes, and propose novel mixed-integer programming models and solution algorithms. Extensive results are provided to gain insights on how the schemes perform in end-to-end delay.
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