理学 文本挖掘评测 释 Topic Detection and Tracking; TDT 话题检测与跟踪会议 由美国国防高级研究计划委员会（DARPA）主办的一个关于信息抽取的会议。又名TDT。
TDT 全称：Terrestrial Dynamical Time。地球力学时
数据库 数据库新技术 释文 topic detection and tracking, TDT 主题检测与跟踪 人工智能 计算语言学 释文 tonic detection and tracking, TDT 话题检测与跟踪
- upper Dirichlet density
- upper end
- upper end of an integral
- upper envelope
- upper estimate
- upper eyelid
- upper finite group
- Upper-flow system
- upper function
- upper gastrointestinal bleeding
- upper gastrointestinal examination
- upper gastrointestinal hemorrhage
- upper girdle muscles
- upper half-disk
- upper half-martingale
- upper half-plane
- upper half-space
- upper harmonic
- upper harmonic wave
- upper heat and lower cold
- upper hemisphere
- upper homology
- upper hybrid frequency
- upper hybrid oscillation
- upper hybrid wave