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Trajectory similarity search (TSS) is a common operation for spatiotemporal data analysis. However, the existing TSS methods are mainly focused on GPS trajectories produced by moving objects such as vehicles. Further, these corresponding optimization strategies cannot be directly applied in the metro scenario because the metro passenger trajectory is totally different from the GPS trajectory. To fill this gap, we systematically analyze the unique spatiotemporal characteristics of metro passenger trajectories and propose a similarity search solution named PMMTss for the metro system. The core idea of this solution has two key points: first, we design a multi-layer index based on the spatiotemporal feature of metro trajectories, and all points of a trajectory are stored in this index. Second, we design a parallel multi-way merging-based trajectory similar search method, in which the candidate trajectory segments are merged and filtered. We evaluate this solution on a large dataset (Shenzhen Metro data for 3 consecutive months, 6.976 million trajectories with 260 million records). When lengths of input trajectories are 16, 32, and 64, respectively, the corresponding search times are 0.004 s, 0.016 s, and 0.036 s, respectively. Compared to the baseline PPJion+, the query times are reduced by 99.7%, 98.8%, and 97.6%, respectively. [ABSTRACT FROM AUTHOR]

The aim of this study was to modify and test the Chinese version of the Revised Illness Perception Questionnaire to measure the illness perception of breast cancer‐related lymphedema among breast cancer survivors. Before the investigation, identity and causal subscales were modified and the wording of the remaining scales was also adjusted. The psychometric properties of this instrument was evaluated using the technique of explore and confirmatory factor analysis. Data from 203 breast cancer survivors was entered into factor analysis. Five causal factors were extracted after removing one item, accounting for 68.02% of the variance in total. An acceptable fit with the data for the proposed seven‐factor model was obtained after eliminating three items and resetting seven error covariances. The Cronbach's α values and composite reliability coefficients were acceptable. This measurement is reliable and valid for measuring illness perceptions of breast cancer‐related lymphedema in Chinese breast cancer survivors. It could be helpful for further studies that examine the effect of illness perceptions on health‐related behaviours, such as lymphedema risk‐reduction behaviours in the Chinese cultural context. [ABSTRACT FROM AUTHOR]