Tagging Problems and Hidden Markov Models 一,标注问题 1,基本定义 通常将源序列x1,x2,..,xnx1,x2,..,xn映射为标记序列y1,y2,...,yny1,y2,...,yn的问题,称为序列标注问题或者标注问题。 序列对建模的任务就是从训练语料中学习一个函数可以将源序列映射为标记序列的函数。 2,两个经典的标注问题 (...
1.Therefore,this method,which originated from the tool of biology technology,is believed to have launched a new episode for solving complexity problems,especially for NP-complete problem.开创了以生物技术为工具解决复杂问题的新纪元,为解决NP完全问题开辟了一条新途径。 2.A general-purpose parallel three...
* * * * * * * L, the class of problems decidable in a logarithmic amount of memory space AL: the set of problems solvable in logarithmic memory by alternating Turing machines PSPACE, the class of problems decidable in polynomial space EXPTIME is the class of problems solvable in ...
Analysis,PCA),是一种统计方法。通过正交变换将一组可能存在相关性的变量转换为一组线性不相关的变量,转换后的这组变量叫主成分。 主成分分析能降低所研究的数据空间的维数。即用研究m维的Y空间代替...对应的特征向量的线性组合来表示每一张人脸,形成由k个最大的d维特征向量表示的人脸库。 直接应用的问题如果d...
NP-COMPLETE PROBLEMSChapter
NP完全性问题 NP-Complete Problems Complexity NPC NP-Complete Problems We can solve any problem(!)(?) … but perhaps not with a computer! Some problems are not computable: The Halting Problem: Write a function boolean halts(Program p, Input i); which returns true if p halts on input i,...
・Numerical problems: SUBSET-SUM, KNAPSACK. 2.1 Asymmetry of NP Asymmetry of NP: We need short certificates only for yes instances. np对称性是指一个NP的反面也是NP问题比如下面的两个对等问题。 2.1.1 NP = co-NP ? Fundamental open question. Does NP = co-NP?
NP-complete problem, any of a class of computational problems for which no efficient solution algorithm has been found. Many significant computer-science problems belong to this class—e.g., the traveling salesman problem, satisfiability problems, and graph-covering problems. So-called easy, or ...
为了证明一个问题是NP complete我们有必要去了解更多的NP complete问题以方便证明,不然每次都只用SAT去证也是挺困难的事情。wiki上有一个列表,基本上很全了:List_of_NP-complete_problems 这里拿一些经典问题来介绍一下。 Set Vertex Cover Problem & Independent Set ...
We consider 3-hypergraphs with and without repeated edges. We prove these problems NP-complete. We indicate their relation to some well-known problems. The corresponding problems for 2-hypergraphs have simple polynomial solutions.Previous article in issue Next article in issue ...