least time path 中文意思是什麼
least time path
解釋
最短時程-
Every time a stem cell divides, at least one daughter remains a stem cell, even though the other may set off on a hayflick - limited path of specialisation
幹細胞每分裂一次，至少會有一個子細胞仍然是幹細胞，而其它子細胞則可能啟動「海弗利克極限」的細胞分化途徑。 -
3 a novel recursive least - square ( rls ) blind space - time receiver algorithm based on the constrained condition, which can completely avoid the matrix inversion introduced into by constraints ( comparing with the normal rls ), is proposed for multi - path slow fading cdma channels. the computational complexity of this method is not only lower than that of the normal rls, but also lower than that of both lms and ls blind space - time receiver methods that are realized based on the rosen ' s gradient projection. and the speed of convergence of the presented rls blind space - time receiver algorithm is better than that of both lms and ls blind space - time receiver methods
3 、針對多徑慢衰落通道下ds - cdma盲空時接收機中線性約束二次規劃問題提出一種新的遞歸最小二乘演算法，該演算法完全避免因約束而引進的矩陣求逆運算（相對于常規的遞歸最小二乘演算法） ，不但運算量比常規的要低，而且比基於rosen梯度投影實現的最小均方（ lms ）與最小二乘盲空時接收機演算法還低，且收斂速度比基於rosen梯度投影實現的最小均方（ lms ）與最小二乘盲空時多用戶檢測都好，將提出的新的遞歸最小二乘演算法與提出的數據選擇方案結合起來可以進一步降低其運算量，具有很大的實用價值，最後通過模擬實驗進一步分析了其性能。 -
Main characteristics of dbxi are : 1 ) a new xml numbering scheme is adopted which enables each element in xml documents carries corresponding dtd structural information. 2 ) a path query with n elements ( or attributes ) and a predicate restriction can be implemented with only 0 or 2 structural join operations per xml document while at least n - 1 times of structural join operations are needed in xiss ( xiss is a kin xml indexing system developed by q. li and b. moon ). 3 ) for a path expression that is not complying with any paths in xml documents, dbxi can give a judgment of no answer in much shorter time than that of sphinx, xiss, etc. experimental results demonstrate that dbxi can process path expressions much faster than lore sphinx and xiss do
Dbxi的主要特點是： 1 ）採用了新的xml編碼方法，使xml文檔中每個元素屬性的編碼攜帶了相應的dtd結構信息； 2 ）對一個由n個元素屬性組成的有一個謂詞約束的路徑表達式， dbxi處理每個xml文檔，由同類系統xiss所需的至少n - 1次結構連接運算，降低至0次或2次結構連接運算； 3 ）如果查詢路徑在待查xml文檔中不存在正確的匹配結構， dbxi能夠在比國際上的sphinx和xiss等xml索引方法較短的時間內給出無查詢結果的判斷。
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