代数码书作为一种流行的固定码书结构,其搜索方法直接影响解码语音质量及计算复杂度。本文提出了一种代数码书分级分段优化搜索GSOS(Graded and Subsection Optimization Search)方法。GSOS方法融合了脉冲替代法、分段搜索及分级优化方...代数码书作为一种流行的固定码书结构,其搜索方法直接影响解码语音质量及计算复杂度。本文提出了一种代数码书分级分段优化搜索GSOS(Graded and Subsection Optimization Search)方法。GSOS方法融合了脉冲替代法、分段搜索及分级优化方法的优点,通过创建优质的初始码书,达到提高初始码书质量的目的,并将码书矢量的乘法运算用分段子码书的加法运算替代,同时将脉冲按贡献不同进行分级,由此提高脉冲替代优化的搜索效率;将该方法用于自适应多速率宽带语音编码器AMR-WB固定码书搜索阶段,实验结果表明,所提出的搜索方法可使固定码书搜索计算量降为深度优先树搜索方法的13.75%,但解码语音质量只降低了4.01%,主观听觉感受基本感觉不出差异。展开更多
Delaunay triangulation has been widely used in many fields such as compu- tational fluid dynamics, statistics, meteorology solid state physics, computational geometry and so on. Bowyer-Watson algorithm is a very popul...Delaunay triangulation has been widely used in many fields such as compu- tational fluid dynamics, statistics, meteorology solid state physics, computational geometry and so on. Bowyer-Watson algorithm is a very popular one for generating Delaunay triangulation. In generating the Delaunay triangulation of a preassigned set of n points, the complexity of Bowyer-Watson algorithm can at most be reduced to O(n log n) for the simple reason that the complexity of its tree search process is O(nlog n). In this paper we suggest a tree search technique whose complexity is O(n). Noting that the order of point insertion can affect the efficiency of Bowyer- Watson algorithm, we propose a technique to optimize the point insertion process. Based on these two techniques, we obtain a fast algorithm for generating Delaunay triangulation.展开更多
文摘代数码书作为一种流行的固定码书结构,其搜索方法直接影响解码语音质量及计算复杂度。本文提出了一种代数码书分级分段优化搜索GSOS(Graded and Subsection Optimization Search)方法。GSOS方法融合了脉冲替代法、分段搜索及分级优化方法的优点,通过创建优质的初始码书,达到提高初始码书质量的目的,并将码书矢量的乘法运算用分段子码书的加法运算替代,同时将脉冲按贡献不同进行分级,由此提高脉冲替代优化的搜索效率;将该方法用于自适应多速率宽带语音编码器AMR-WB固定码书搜索阶段,实验结果表明,所提出的搜索方法可使固定码书搜索计算量降为深度优先树搜索方法的13.75%,但解码语音质量只降低了4.01%,主观听觉感受基本感觉不出差异。
文摘Delaunay triangulation has been widely used in many fields such as compu- tational fluid dynamics, statistics, meteorology solid state physics, computational geometry and so on. Bowyer-Watson algorithm is a very popular one for generating Delaunay triangulation. In generating the Delaunay triangulation of a preassigned set of n points, the complexity of Bowyer-Watson algorithm can at most be reduced to O(n log n) for the simple reason that the complexity of its tree search process is O(nlog n). In this paper we suggest a tree search technique whose complexity is O(n). Noting that the order of point insertion can affect the efficiency of Bowyer- Watson algorithm, we propose a technique to optimize the point insertion process. Based on these two techniques, we obtain a fast algorithm for generating Delaunay triangulation.
