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算法中的随机性，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期间可视化脑电图信号中的纺锤体结构。