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排序方式: 共有1119条查询结果,搜索用时 62 毫秒
61.
Ram C. Tiwari 《统计学通讯:理论与方法》2013,42(2):625-642
In this paper, a nonparametric Bayesian approach to the analysis of binary response data is considered. Using a Dirichlet process prior, and squared error loss, the Bayes estimators of response probabilities are obtained. Finally, the results obtained are employed to analyze the ARC 090 Trial data. 相似文献
62.
赵苗 《山西高等学校社会科学学报》2013,25(1):98-100
杨红樱的作品秉承"教育应该把人性关怀放在首位"的教育理念,充分张扬孩子的天性。其作品侧重树立成人是儿童童年的捍卫者、童心的守护者、儿童的贴心者和成长的引导者,并从这四个方面塑造了成人形象。 相似文献
63.
对于所采集的条码图像,为了适应实时性的要求,以得到不同光照条件下的最佳阈值,该文提出了把直方图双峰法、OTSU法及NLNiblack阈值法结合起来的改进的自适应阈值法。实验证明了该方法具有高效性和稳定性。为了在条码分割图像中获取QR码的4个顶点,首先,根据3个位置探测图形的特性提出了一种新的方法以求取对应的3个顶点,同时利用QR码的特征提出挖空算法获取条码的边缘,再采用过已知点的Hough变换得到第4个顶点。实验证明该算法在各种采集条件下可有效地得到QR码的4个顶点。 相似文献
64.
Gabriel Chandler Leif T. Johnson 《Journal of Statistical Computation and Simulation》2013,83(2):384-401
Tree-based methods similar to CART have recently been utilized for problems in which the main goal is to estimate some set of interest. It is often the case that the boundary of the true set is smooth in some sense, however tree-based estimates will not be smooth, as they will be a union of ‘boxes’. We propose a general methodology for smoothing such sets that allows for varying levels of smoothness on the boundary automatically. The method is similar to the idea underlying support vector machines, which is applying a computationally simple technique to data after a non-linear mapping to produce smooth estimates in the original space. In particular, we consider the problem of level-set estimation for regression functions and the dyadic tree-based method of Willett and Nowak [Minimax optimal level-set estimation, IEEE Trans. Image Process. 16 (2007), pp. 2965–2979]. 相似文献
65.
We investigate the computational complexity of two special cases of the Steiner tree problem where the distance matrix is a Kalmanson matrix or a circulant matrix, respectively. For Kalmanson matrices we develop an efficient polynomial time algorithm that is based on dynamic programming. For circulant matrices we give an
-hardness proof and thus establish computational intractability. 相似文献
66.
Leszek Gasieniec Jesper Jansson Andrzej Lingas Anna Östlin 《Journal of Combinatorial Optimization》1999,3(2-3):183-197
In this paper we study a few important tree optimization problems with applications to computational biology. These problems ask for trees that are consistent with an as large part of the given data as possible. We show that the maximum homeomorphic agreement subtree problem cannot be approximated within a factor of
, where N is the input size, for any 0
in polynomial time unless P = NP, even if all the given trees are of height 2. On the other hand, we present an O(N log N)-time heuristic for the restriction of this problem to instances with O(1) trees of height O(1) yielding solutions within a constant factor of the optimum. We prove that the maximum inferred consensus tree problem is NP-complete, and provide a simple, fast heuristic for it yielding solutions within one third of the optimum. We also present a more specialized polynomial-time heuristic for the maximum inferred local consensus tree problem. 相似文献
67.
彭红卫 《三峡大学学报(人文社会科学版)》2004,26(4):35-38
由于对传统的因袭和对大众口味的迎合,新武侠小说作家在创作中遵从男性视角以及对男权潜意识的向往使作品在女性观上基本没有什么突破,因而在女性形象的塑造上显得底气不足而有先天缺陷,他们的作品塑造的只是男性希望看到的女性,而不是真正的女性.新武侠小说建立的是一个美妙的以"情"义"为出发点的男人的乌托邦,因而在女权主义高涨的今天,这一文学样式的衰落是可预期的. 相似文献
68.
This paper proposes an optimization model and shows that most inverse combinatorial optimization problems so far discussed can be fit into this model as special cases. We propose a Newton-type algorithm for this model under l
norm. This algorithm can solve the model in strongly polynomial time if the subproblem involved is solvable in strongly polynomial time for any fixed value of the parameter appearing in the subproblem, and it is shown that most particular inverse optimization problems encountered are this kind. Therefore, through this paper we show that a large group of inverse optimization problems can be handled in a uniform way and solved in strongly polynomial time. 相似文献
69.
Yoshiyuki Kusakari Daisuke Masubuchi Takao Nishizeki 《Journal of Combinatorial Optimization》2001,5(2):249-266
Let G = (V,E) be a plane graph with nonnegative edge weights, and let
be a family of k vertex sets
, called nets. Then a noncrossing Steiner forest for
in G is a set
of k trees
in G such that each tree
connects all vertices, called terminals, in net N
i, any two trees in
do not cross each other, and the sum of edge weights of all trees is minimum. In this paper we give an algorithm to find a noncrossing Steiner forest in a plane graph G for the case where all terminals in nets lie on any two of the face boundaries of G. The algorithm takes time
if G has n vertices and each net contains a bounded number of terminals. 相似文献
70.
“神”意象生命美的生成 总被引:1,自引:0,他引:1
柳倩月 《湖北民族学院学报(哲学社会科学版)》2003,21(5):23-27
中国古典哲学之"气"范畴是文学"神"意象生命意义生成的本体,从马克思主义人本主义生命观看,生命自由与生命平等是生命的本质特征。 相似文献