Concentration of frequency and time (ConceFT) is a generalized multitaper algorithm introduced to analyze complicated non-stationary time series. To avoid the randomness in the original ConceFT algorithm, we apply the novel complex spherical design technique to standardize ConceFT, which we coin CQU-ConceFT. The proposed CQU-ConceFT is applied to visualize the spindle structure in the electroencephalogram signal during the N2 sleep stage and other physiological time series.

中文翻译：

---

通过新颖的复杂球形设计提高频率和时间的集中度（ConceFT）

频率和时间集中度（ConceFT）是一种通用的多锥度算法，用于分析复杂的非平稳时间序列。为了避免原始ConceFT算法的随机性，我们将新颖的复杂球形设计技术应用于ConceFT的标准化，我们将其称为CQU-ConceFT。提出的CQU-ConceFT用于在N2睡眠阶段和其他生理时间序列中可视化脑电图信号中的纺锤体结构。