基于新的相异度量的模糊K-Modes聚类算法

传统的模糊K-Modes聚类算法采用简单匹配方法度量对象与Mode之间的相异程度,没有充分考虑Mode对类的代表程度,容易造成信息的丢失,弱化了类内的相似性。针对上述问题,通过对象对类的隶属度反映Mode对类的代表程度,提出一种新的相异度量,并将它应用于传统的模糊K—Modes聚类算法。与传统的K—Modes和模糊K-Modes聚类算法相比,该相异度量是有效的。     

基于二维属性的高维数据聚类算法研究

聚类就是按照一定的要求和规律对事物进行区分和分类的过程.在这一过程中没有任何关于类别的先验知识,也没有教师的指导,仅靠事物间的相似性作为类属划分的准则,因此属于元监督分类的范畴.聚类分析则是指用数学的方法研究和处理给定对象的分类.针对目前很多聚类算法只能对低维数据进行聚类的问题,提出了一种改进的相异度度量方法对二维属性的高维数据采用层次分裂算法进行聚类,而且根据用户指定的参数聚类,并对传统相异度度量和改进的相异度度量方法的聚类结果进行比较,发现改进的相异度度量方法更适用于二维属性的高维数据的聚类.     

面向分类属性数据的一种改进相异性度量及其在客户细分中的应用*

具有层次结构的分类属性在客户细分应用中广泛存在。针对传统相异性度量无法准确反映决策者在与细分目标相关的决策指标上的偏好信息,提出一种改进的距离层次并给出使用该度量,基于聚类分析的客户细分基本流程。该度量利用距离层次计算各分类属性值概念间的相异性,同时引入指标距离的概念描述对于特定指标,决策者在不同分类属性值上的偏好,结合模糊相似优先比决策方法和树的广度优先遍历计算不同分类属性值间的指标距离,最后通过将所求得的概念距离和指标距离进行加权求和以更全面地度量不同分类属性值间的相异性。对陕西省电力公司工业客户进行细分实验的结果表明：与传统距离层次相比,采用改进相异性度量能提高聚类质量和细分结果的可解释性。     

基于免参数据挖掘的相异度度量研究

由于参数设置导致数据挖掘结果异常的例子很多，为了解决这一问题，出现了免参数据挖掘思想。对Kolmogorov复杂度理论进行了研究，将其和免参数据挖掘思想相结合，提出了一种基于压缩的相异度度量SCDM。由于压缩算法是空间和时间高效性算法，使得应用该算法的相异度度量也具有较好的性能。实验表明将这种相异度度量应用到层次聚类算法中，其聚类的准确率也较高。     

高维数据相似性度量方法研究

将低维空间中的距离度量方法(如Lk-范数)应用于高维空间时,随着维数的增加,对象之间距离的对比性将不复存在。研究高维数据有效的距离或相似(相异)度度量方法是一个重要且具有挑战性的课题。通过对传统的距离度量或相似性(相异性)度量方法在高维空间中表现出的不适应性的分析,并对现有的应用于高维数据的相似性度量方法进行总结,提出了高维数据相似性度量函数Hsim(X,Y)的改进方法HDsim(X,Y)。函数HDsim(X,Y)整合了各类型数据的相似性度量方法,在处理数值型、二值型以及分类属性数据上充分体现了原Hsim(X,Y)处理数值型数据、Jaccard系数处理二值数据以及匹配率处理分类属性数据的优越性。通过有效性及实例分析,充分论证了HDsim(X,Y)在高维空间中的有效性。     

直觉模糊相似关系的构造方法

传统的模糊相似关系构造方法已不能用于直觉模糊相似关系的构造。基于直觉模糊集的相异度和相似度,研究了直觉模糊相似关系的构造问题。对几种现有直觉模糊集相似度与相异度度量方法进行了分析,在此基础上定义了直觉模糊集的相异度,并给出一种有效的直觉模糊集相异度和相似度度量方法,提出一种实用的直觉模糊相似关系构造方法,以具体算例验证和表明了方法的正确性和有效性。     

优化的粗糙神经网络在故障诊断中的应用

本文在相异度理论的基础上，提出了类间相异度的度量方法，从而以粗糙集理论为属性约简工具，利用相异度理论进行类的泛化和特化．构造出了优化的粗糙神经网络模型。故障诊断实例分析表明，该模型对神经网络分层约简并剔除其中不必要的属性．减少了神经网络的总体训练时间和决策过程中的模式匹配搜索量，大大提高故障诊断系统的反应能力，在大型复杂的故障诊断应用中效果尤为明显。     

基于局部相似性的复杂网络社区发现方法

复杂网络是复杂系统的典型表现形式, 社区结构是复杂网络最重要的结构特征之一. 针对复杂网络的社区结构发现问题, 本文提出一种新的局部相似性度量, 并结合层次聚类算法用于社区结构发现. 相对全局的相似性度量, 本文提出的相似性度量具有较低的计算开销; 同时又能很好地刻画网络的结构特征, 克服了传统局部相似性度量在某些情形下对节点相似性的低估倾向. 为了将局部相似性度量用于社区结构发现, 推广了传统的Ward层次聚类算法, 使之适用于具有相似性度量的任意对象, 并将其用于复杂网络社区结构发现. 在合成和真实世界的网络上进行了实验, 并与典型算法进行了比较, 实验结果表明所提算法的可行性和有效性.     

对模板的测试覆盖度量

分析了传统覆盖度量应用在模板函数和模板类测试时的不足，定义了新的覆盖度量。新的定义考虑了参数类型或对象所处的状态，较传统的定义更能保证测试的充分性。     

基于新相异度量的模糊K-Modes聚类算法

提出了一种基于新相异度量的模糊K-Modes算法。该算法假定不同属性对聚类结果有不同程度的影响,定义了新的属性值函数,以基于划分相似度的聚类精确度作为聚类结果的评价准则。通过真实数据的实验结果表明,新的基于相异度量的模糊K-Modes算法比传统的模糊K-Modes算法有更好的聚类效果。     

On the similarity metric and the distance metric

Similarity and dissimilarity measures are widely used in many research areas and applications. When a dissimilarity measure is used, it is normally required to be a distance metric. However, when a similarity measure is used, there is no formal requirement. In this article, we have three contributions. First, we give a formal definition of similarity metric. Second, we show the relationship between similarity metric and distance metric. Third, we present general solutions to normalize a given similarity metric or distance metric.     

A scalable kernel-based semisupervised metric learning algorithm with out-of-sample generalization ability

In recent years, metric learning in the semisupervised setting has aroused a lot of research interest. One type of semisupervised metric learning utilizes supervisory information in the form of pairwise similarity or dissimilarity constraints. However, most methods proposed so far are either limited to linear metric learning or unable to scale well with the data set size. In this letter, we propose a nonlinear metric learning method based on the kernel approach. By applying low-rank approximation to the kernel matrix, our method can handle significantly larger data sets. Moreover, our low-rank approximation scheme can naturally lead to out-of-sample generalization. Experiments performed on both artificial and real-world data show very promising results.     

Combining supervised and unsupervised learning for data clustering

Clustering aims to partition a data set into homogenous groups which gather similar objects. Object similarity, or more often object dissimilarity, is usually expressed in terms of some distance function. This approach, however, is not viable when dissimilarity is conceptual rather than metric. In this paper, we propose to extract the dissimilarity relation directly from the available data. To this aim, we train a feedforward neural network with some pairs of points with known dissimilarity. Then, we use the dissimilarity measure generated by the network to guide a new unsupervised fuzzy relational clustering algorithm. An artificial data set and a real data set are used to show how the clustering algorithm based on the neural dissimilarity outperforms some widely used (possibly partially supervised) clustering algorithms based on spatial dissimilarity.     

Relaxational metric adaptation and its application to semi-supervised clustering and content-based image retrieval

The performance of many supervised and unsupervised learning algorithms is very sensitive to the choice of an appropriate distance metric. Previous work in metric learning and adaptation has mostly been focused on classification tasks by making use of class label information. In standard clustering tasks, however, class label information is not available. In order to adapt the metric to improve the clustering results, some background knowledge or side information is needed. One useful type of side information is in the form of pairwise similarity or dissimilarity information. Recently, some novel methods (e.g., the parametric method proposed by Xing et al.) for learning global metrics based on pairwise side information have been shown to demonstrate promising results. In this paper, we propose a nonparametric method, called relaxational metric adaptation (RMA), for the same metric adaptation problem. While RMA is local in the sense that it allows locally adaptive metrics, it is also global because even patterns not in the vicinity can have long-range effects on the metric adaptation process. Experimental results for semi-supervised clustering based on both simulated and real-world data sets show that RMA outperforms Xing et al.'s method under most situations. Besides applying RMA to semi-supervised learning, we have also used it to improve the performance of content-based image retrieval systems through metric adaptation. Experimental results based on two real-world image databases show that RMA significantly outperforms other methods in improving the image retrieval performance.     

Fast k-nearest neighbor classification using cluster-based trees

Most fast k-nearest neighbor (k-NN) algorithms exploit metric properties of distance measures for reducing computation cost and a few can work effectively on both metric and nonmetric measures. We propose a cluster-based tree algorithm to accelerate k-NN classification without any presuppositions about the metric form and properties of a dissimilarity measure. A mechanism of early decision making and minimal side-operations for choosing searching paths largely contribute to the efficiency of the algorithm. The algorithm is evaluated through extensive experiments over standard NIST and MNIST databases.     

基于后件直联型分层的广义混合模糊系统及其积分模逼近

首先, 引入后件直联型分层方法及其推理规则, 以对广义混合模糊系统的输入变量实施分层, 获得分层广义混合模糊系统的输入输出表达式和推理规则数的计算公式; 然后, 基于??- 积分模(度量) 和分片线性函数证明分层后广义混合模糊系统对一类可积函数具有逼近性; 最后, 通过模拟实例给出后件直联型分层广义混合模糊系统对可积函数的逼近过程. 模拟结果表明, 所提出的方法不仅能使原系统模糊规则总数大大减少, 而且能使分层后系统仍具有逼近性.

     

Axiom selection over large theory based on new first-order formula metrics

Axiom selection is a task that selects the most likely useful axioms from a large-scale axiom set for proving a given conjecture. Existing axiom selection methods either solely take shallow symbols into account or strongly dependent on previous successful proofs from homologous problems. To address these problems, we introduce a new metric to evaluate the dissimilarity between formulae and utilize it as an evaluator in the selection task. Firstly, we propose a substitution-based metric to compute the dissimilarity between terms. It is a pseudo-metric and can capture the in-depth syntactic difference trigged by both functional and variable subterms. We then extend it to atoms and prove the atom metric also to be a pseudo-metric. Treating formulae as atom sets, we define three kinds of dissimilarity metrics between formulae. Finally, we design and implement conjecture-oriented axiom selection methods based on newly proposed formula metrics. The experimental evaluation is conducted on the MPTP2078 benchmark and demonstrates dissimilarity-based axiom selection improves E prover’s performance. In the best case, it increases the ratio of successful proofs from 30.90% to 42.25%.

     

A Kernel Approach for Semisupervised Metric Learning

While distance function learning for supervised learning tasks has a long history, extending it to learning tasks with weaker supervisory information has only been studied recently. In particular, some methods have been proposed for semisupervised metric learning based on pairwise similarity or dissimilarity information. In this paper, we propose a kernel approach for semisupervised metric learning and present in detail two special cases of this kernel approach. The metric learning problem is thus formulated as an optimization problem for kernel learning. An attractive property of the optimization problem is that it is convex and, hence, has no local optima. While a closed-form solution exists for the first special case, the second case is solved using an iterative majorization procedure to estimate the optimal solution asymptotically. Experimental results based on both synthetic and real-world data show that this new kernel approach is promising for nonlinear metric learning     

基于有效产出会计的商业智能系统

长期以来“稳定”与“成长”的矛盾始终存在于企业的管理中。相比传统的妥协方案,有效产出会计从系统整体的视角提出了可以同时满足两个需求的双赢解。引入有效产出的观念,提出一套从产出视角对供应链进行管理的绩效指标体系,并使用商业智能技术设计并实现相应的决策支持系统并实际应用。该系统的可行性及有效性已得到实际验证。