Abstract:State of health (SOH) prognostics is significant for safe and reliable usage of lithium-ion batteries. To accurately predict regeneration phenomena and improve long-term prediction performance of battery SOH, this paper proposes a rest time-based prognostic framework (RTPF) in which the beginning time interval of two adjacent cycles is adopted to reflect the rest time. In this framework, SOH values of regeneration cycles, the number of cycles in regeneration regions and global degradation trends are extracted from raw SOH time series and predicted respectively, and then the three sets of prediction results are integrated to calculate the final overall SOH prediction values. Regeneration phenomena can be found by support vector machine and hyperplane shift (SVM-HS) model by detecting long beginning time intervals. Gaussian process (GP) model is utilized to predict the global degradation trend, and nonlinear models are utilized to predict the regeneration amplitude and the cycle number of each regeneration region. The proposed framework is validated through experimental data from the degradation tests of lithium-ion batteries. The results demonstrate that both the global degradation trend and the regeneration phenomena of the testing batteries can be well predicted. Moreover, compared with the published methods, more accurate SOH prediction results can be obtained under this framework.

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Airport connectivity can improve the competitiveness of regions by attracting tourism and inward investment. Regions traditionally accessed international destinations via connecting flights to national gateway airports usually operated by full service network carriers (FSNC). However, the entry of low-cost carriers (LCC) in these markets has led to changes in incumbent FSNC service provision. We analyse how intra-European connectivity has changed at small airports between 2002 and 2012 and how LCC entry has affected the quality of day-return schedules in these markets. Results show that offline LCC connectivity is greater than that scheduled by FSNCs. Furthermore, LCC entry had a negative effect on the quality of the connectivity offered by FSNCs. Interestingly, we also found that day-return itineraries become more difficult for passengers in markets where the LCC is the sole operator. Regional policy-makers may need to more carefully consider the connectivity implications in the design of LCC start-up incentive schemes.

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