一种时间序列频繁模式挖掘算法及其在WSAN行为预测中的应用

该文提出FPM(Frequent Pattern Mining)算法充分考虑频繁模式在时间序列中出现次数和分布。基于这些不同分布的频繁模式扩展MAMC(Mixed memory Aggregation Markov Chain)模型提出FMAMC(Frequent pattern based Mixed memory Aggregation Markov Chain)模型。将FPM和FMAMC应用到实际的智能楼宇项目中,证明和现有算法相比FPM算法具有较好的时间性能,FMAMC模型能够比MAMC模型更准确的预测WSAN节点行为。     

Size of random Galois lattices and number of closed frequent itemsets

Given a sample of binary random vectors with i.i.d. Bernoulli(p) components, that is equal to 1 (resp. 0) with probability p (resp. 1−p), we first establish a formula for the mean of the size of the random Galois lattice built from this sample, and a more complex one for its variance. Then, noticing that closed α-frequent itemsets are in bijection with closed α-winning coalitions, we establish similar formulas for the mean and the variance of the number of closed α-frequent itemsets. This can be interesting for the study of the complexity of some data mining problems such as association rule mining, sequential pattern mining and classification.     

Graph-based approach for human action recognition using spatio-temporal features

Due to the exponential growth of the video data stored and uploaded in the Internet websites especially YouTube, an effective analysis of video actions has become very necessary. In this paper, we tackle the challenging problem of human action recognition in realistic video sequences. The proposed system combines the efficiency of the Bag-of-visual-Words strategy and the power of graphs for structural representation of features. It is built upon the commonly used Space–Time Interest Points (STIP) local features followed by a graph-based video representation which models the spatio-temporal relations among these features. The experiments are realized on two challenging datasets: Hollywood2 and UCF YouTube Action. The experimental results show the effectiveness of the proposed method.     

针对垂直数据分布数据库的一种关联规则挖掘算法

频繁模式树算法是一种优秀的关联规则挖掘算法．频繁模式树算法的挖掘对象是水平数据分布的数据库，现实中有大量数据垂直分布的数据库不能直接应用频繁模式树算法进行挖掘．本文针对垂直数据分布的数据库，提出一种有效的频繁模式树生长算法，只需两次数据库扫描，即可生成相应的频繁模式树．     

变电站PT熔断器频繁烧毁的原因分析

本文结合生活中变电站PT熔断器的实际应用,着重对PT熔断器频繁烧毁的原因和解决措施进行分析,为我国电力资源有效运用提供理论参考.     

关联规则挖掘算法

关联规则挖掘是数据挖掘和知识发现中的一个重要问题．自提出以来得到了广泛的研究。目前关联规则挖掘算法可以分为广度优先算法和深度优先算法两大类，每类都有经典高效的算法提出。但是．这些算法大都是从其自身的角度来描述的，缺乏系统的分类和比较。文章从关联规则挖掘的形式化定义出发，给出频集挖掘的解空间，对两大类算法中的几种经典算法进行了概述，并分析了它们的优缺点。     

信任网络中多维信任序列模式挖掘方法研究

现有信任网络研究大多侧重于信任的推理及聚合计算,缺乏对实体重要性及其关联性分析,为此该文提出一种多维信任序列模式(Multi-dimensional Trust Sequential Patterns, MTSP)挖掘算法。该算法包括频繁信任序列挖掘和多维模式筛选两个处理过程,综合考虑信任强度、路径长度和实体可信度等多维度因素,有效地挖掘出信任网络中的频繁多维信任序列所包含的重要实体及其关联结构。仿真实验表明该文所提MTSP算法的挖掘结果全面、准确地反映了信任网络中重要信任实体关联性及其序列结构特征。     

Novel Approach to Minimize the Memory Requirements of Frequent Subgraph Mining Techniques

Frequent subgraph mining (FSM) is a subset of the graph mining domain that is extensively used for graph classification and clustering. Over the past decade, many efficient FSM algorithms have been devel-oped with improvements generally focused on reducing the time complexity by changing the algorithm structure or using parallel programming techniques. FSM algorithms also require high memory consumption, which is another problem that should be solved. In this paper, we propose a new approach called Predictive dynamic sized structure packing (PDSSP) to minimize the memory needs of FSM algorithms. Our approach redesigns the internal data structures of FSM algorithms without making algorithmic modifications. PDSSP offers two contributions. The first is the Dynamic Sized Integer Type, a newly designed unsigned integer data type, and the second is a data structure packing technique to change the behavior of the compiler. We examined the effectiveness and efficiency of the PDSSP approach by experimentally embedding it into two state-of-the-art algorithms, gSpan and Gaston. We compared our implementations to the performance of the originals. Nearly all results show that our proposed implementation consumes less memory at each support level, suggesting that PDSSP extensions could save memory, with peak memory usage decreasing up to 38％depending on the dataset.     

Criteria-based alarm flood pattern recognition using historical data from automated production systems (aPS)

The operation of industrial automated production systems (aPS) usually requires human operators that observe and, if necessary, intervene to keep aPS in steady operation. Inside the distributed control system (DCS) of an aPS, notifications are generated by an alarm management system (AMS) and visualized, informing operators about critical aPS situations, e.g. faults of a device. Since a huge number of notifications are usually configured inside the AMS, operators nowadays often face the problem of receiving more notifications than they can physically address. This paper proposes an approach, which allows automatic identification of alarm floods by using criteria-based search strategies. In order to address the problem statement, four hypotheses are stated. To evaluate the proposed algorithm regarding its ability to identify causally dependent notifications, historical notification logs of real industrial aPS are analyzed. For this purpose, notification logs of eight existing industrial aPS as well as the assessment of industrial experts are taken into account.