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State of charge (SOC) estimation is a key issue in battery management systems. The challenge lies in balancing the trade-off between accuracy and computation cost. To this end, we propose an alternate method by combining the ampere-hour integral (AHI) method which has low computation cost, and the adaptive extended Kalman filter (AEKF) method, which has high accuracy. The technical viability of this alternate method is verified on a LiMnO2-LiNiO2 battery module with a nominal capacity of 130 Ah under the New European Driving Cycle (NEDC) condition. Drifts in current and voltage measurement are considered. The experimental results show that the absolute SOC error using the AHI method monotonously increases from 0% to 7.2% with the computation time of 10 s while the calculation time is obtained on a ThinkPad E450 PC with an Intel Core i7-5500U CPU @2.40 GHz and 16.0 GB RAM. The absolute SOC error of the AEKF method maintains within 3.5% with the computation time of 49 s. Therefore, the alternate method almost maintains the same SOC accuracy compared to the AEKF method which reduces the maximum absolute SOC error by 50% compared to the AHI method. Therefore, the alternate method almost has the same computation time compared with the AHI method which reduces the computation time by nearly 75% compared to the AEKF method.

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The Coronavirus Disease 2019 appeared in December 2019 in China and has infected more than 100,000 patients in China since then. After MDT (multi-disciplinary team treatment), more than 60,000 patients were cured and discharged from the isolation wards of designated hospitals. All of the discharged patients were negative as assayed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) tests.Based on Chinese government guidelines, these discharge patients needed to remain in isolation in the home for 2 weeks followed by additional follow-up nucleic acid testing and chest CT examination. However, some discharged patients have retested positive using nucleic acid tests. Reports of these scattered cases have drawn huge scrutiny. Unfortunately, there are some relevant issues needing resolution. First, the capacity for transmission between persons with these patients after positive diagnosis still needs to be determined. Second, the features of serial chest CT scans need to be analyzed to improve our awareness of these cases. Finally, the reason causing these positive retest results should be discussed.We report here the serial CT examination features of two cluster transmission cases with positive follow-up nucleic acid test results after discharge.