次优搜索算法中常用的FSS算法，即顺序前进算法，上种自上而下的搜索方法。-suboptimal search algorithm commonly used algorithm of the FSS, the order ahead algorithm, on the kinds of top-down search method.

基于锁相环Top-down的建模方法在MATLAB环境下建立数字锁相环完整的仿真模型，并用SIMULINK对数字锁相环的仿真模型进行仿真。　-Top-down phase-locked loop based on the modeling method in MATLAB environment DPLL set up a complete simulation model, and use of digital phase-locked loop SIMULINK simulation mod

The algorithm ID3 (Quinlan) uses the method top-down induction of decision trees. Given a set of classified examples a decision tree is induced, biased by the information gain measure, which heuristically leads to small trees. The examples are given