An efficient algorithm for mining temporal high utility itemsets from data streams

Utility of an itemset is considered as the value of this itemset, and utility mining aims at identifying the itemsets with high utilities. The temporal high utility itemsets are the itemsets whose support is larger than a pre-specified threshold in current time window of the data stream. Discovery of temporal high utility itemsets is an important process for mining interesting patterns like association rules from data streams. In this paper, we propose a novel method, namely THUI (Temporal High Utility Itemsets)-Mine, for mining temporal high utility itemsets from data streams efficiently and effectively. To the best of our knowledge, this is the first work on mining temporal high utility itemsets from data streams. The novel contribution of THUI-Mine is that it can effectively identify the temporal high utility itemsets by generating fewer candidate itemsets such that the execution time can be reduced substantially in mining all high utility itemsets in data streams. In this way, the process of discovering all temporal high utility itemsets under all time windows of data streams can be achieved effectively with less memory space and execution time. This meets the critical requirements on time and space efficiency for mining data streams. Through experimental evaluation, THUI-Mine is shown to significantly outperform other existing methods like Two-Phase algorithm under various experimental conditions.     

持续时态数据挖掘的研究

基于一阶线性时态逻辑。形式化定义时态数据挖掘中的主要概念。利用线性状态结构对每个时间点上的一阶语言符号进行赋值。并度量公式的真值范围．按照挖掘段概念．开发持续挖掘过程模型,用于归纳局部一阶规则与推导高阶规则．基于信息扩散原理．提出一阶规则的度量值估计方法和规则泛化算法．最后通过算例说明了扩散估计和算法的有效性．     

Mining fuzzy temporal association rules by item lifespans

Data mining is the process of extracting desirable knowledge or interesting patterns from existing databases for specific purposes. In real-world applications, transactions may contain quantitative values and each item may have a lifespan from a temporal database. In this paper, we thus propose a data mining algorithm for deriving fuzzy temporal association rules. It first transforms each quantitative value into a fuzzy set using the given membership functions. Meanwhile, item lifespans are collected and recorded in a temporal information table through a transformation process. The algorithm then calculates the scalar cardinality of each linguistic term of each item. A mining process based on fuzzy counts and item lifespans is then performed to find fuzzy temporal association rules. Experiments are finally performed on two simulation datasets and the foodmart dataset to show the effectiveness and the efficiency of the proposed approach.     

Incremental fuzzy temporal association rule mining using fuzzy grid table

Traditional temporal association rules mining algorithms cannot dynamically update the temporal association rules within the valid time interval with increasing data. In this paper, a new algorithm called incremental fuzzy temporal association rule mining using fuzzy grid table (IFTARMFGT) is proposed by combining the advantages of boolean matrix with incremental mining. First, multivariate time series data are transformed into discrete fuzzy values that contain the time intervals and fuzzy membership. Second, in order to improve the mining efficiency, the concept of boolean matrices was introduced into the fuzzy membership to generate a fuzzy grid table to mine the frequent itemsets. Finally, in view of the Fast UPdate (FUP) algorithm, fuzzy temporal association rules are incrementally mined and updated without repeatedly scanning the original database by considering the lifespan of each item and inheriting the information from previous mining results. The experiments show that our algorithm provides better efficiency and interpretability in mining temporal association rules than other algorithms.

     

Discovery of fuzzy temporal association rules

We propose a data mining system for discovering interesting temporal patterns from large databases. The mined patterns are expressed in fuzzy temporal association rules which satisfy the temporal requirements specified by the user. Temporal requirements specified by human beings tend to be ill-defined or uncertain. To deal with this kind of uncertainty, a fuzzy calendar algebra is developed to allow users to describe desired temporal requirements in fuzzy calendars easily and naturally. Fuzzy operations are provided and users can define complicated fuzzy calendars to discover the knowledge in the time intervals that are of interest to them. A border-based mining algorithm is proposed to find association rules incrementally. By keeping useful information of the database in a border, candidate itemsets can be computed in an efficient way. Updating of the discovered knowledge due to addition and deletion of transactions can also be done efficiently. The kept information can be used to help save the work of counting and unnecessary scans over the updated database can be avoided. Simulation results show the effectiveness of the proposed system. A performance comparison with other systems is also given.     

一种基于FP-树的时态关联规则的分区挖掘方法

随着各种形式的数据的迅速增长，业务数据中的时态信息挖掘问题受到人们普遍关注。该文提出了一种带有效时间区间的时态关联规则，给出了一种基于FP-树的挖掘方法。该方法利用分区挖掘的思想，以分区为单位表示项集的有效时间区间，并为每个分区构建FP-树，大大简化了对某个项集在其有效时间区间中的出现次数的计算，从而更有效地计算时态置信度。最后用一个例子对该方法的执行过程进行了阐述。     

一种加权时态关联规则挖掘算法

许多现实数据库都存在时态语义问题,因此在挖掘关联规则时附加上时态约束会使规则更具有实际意义。但目前提出的大多数时态关联规则挖掘算法,一般都认为每个数据项的重要性相同,而从决策者角度出发,往往会优先考虑利润较高的项目。提出了一种加权时态关联规则挖掘算法,以项目的生命周期作为时间特征,允许用户设定不同的项目权重。实验结果证明,该算法不仅能有效地发现加权时态关联规则,而且挖掘出的规则更有价值。     

Mining temporal explicit and implicit semantic relations between entities using web search engines

In this paper, we study the problem of mining temporal semantic relations between entities. The goal of the studied problem is to mine and annotate a semantic relation with temporal, concise, and structured information, which can release the explicit, implicit, and diversity semantic relations between entities. The temporal semantic annotations can help users to learn and understand the unfamiliar or new emerged semantic relations between entities. The proposed temporal semantic annotation structure integrates the features from IEEE and Renlifang. We propose a general method to generate temporal semantic annotation of a semantic relation between entities by constructing its connection entities, lexical syntactic patterns, context sentences, context graph, and context communities. Empirical experiments on two different datasets including a LinkedIn dataset and movie star dataset show that the proposed method is effective and accurate. Different from the manually generated annotation repository such as Wikipedia and LinkedIn, the proposed method can automatically mine the semantic relation between entities and does not need any prior knowledge such as ontology or the hierarchical knowledge base. The proposed method can be used on some applications, which proves the effectiveness of the proposed temporal semantic relations on many web mining tasks.     

基于频繁项集树的时态关联规则挖掘算法

针对目前时态关联规则研究中存在的挖掘效率不高、规则可解释性低、未考虑项集时间关联关系等问题,在原有相关研究的基础上,提出一种新的基于频繁项集树的时态关联规则挖掘算法.通过对时间序列数据进行降维离散化处理,采用向量运算生成频繁项集,提高频繁项集挖掘效率.考虑到项集之间的时态关系以及树结构的优势,提出一种新的频繁项集树结构挖掘时态关联规则,其挖掘频繁项集与树结构构建同时进行,无需产生候选项集,提高了规则挖掘效率.实验表明,对比于其他算法,所提出算法在挖掘效率和规则解释性方面效果更好,具有较好的应用前景.     

一种改进的Apriori算法

数据挖掘中的关联规则挖掘能够发现大量数据中项集之间有趣的关联或相关联系,特别是随着大量数据不停地收集和存储,从数据库中挖掘关联规则就越来越有其必要性。通过对关联规则挖掘技术及其相关算法Apriori进行分析,发现该技术存在的问题。Apriori算法是关联规则挖掘中的经典算法。对Apriori算法做了改进。借助0—1矩阵给出了计算项集的支持度计数的更快方法,同时还简化了Apriori算法中的连接和剪枝操作,从而在时间和空间上提高了Apriori算法的效率。     

First-order temporal pattern mining with regular expression constraints

Previous studies on mining sequential patterns have focused on temporal patterns specified by some form of propositional temporal logic. However, there are some interesting sequential patterns, such as the multi-sequential patterns, whose specification needs a more expressive formalism, the first-order temporal logic. Multi-sequential patterns appear in different application contexts, for instance in spatial census data mining, which is the target application of the study developed in this paper. We extend a well-known user-controlled tool, based on regular expressions constraints, to the multi-sequential pattern context. This specification tool enables the incorporation of user focus into the mining process. We present MSP-Miner, an Apriori-based algorithm to discover all frequent multi-sequential patterns satisfying a user-specified regular expression constraint.     

时序规则挖掘

提出了新颖的时间序列模式和规则挖掘技术。该技术先把待挖掘的时间序列转换成子时间序列数据,然后利用子时间序列所隐藏的知识,来指导对原时间序列的挖掘,从中提取模式或规则。给出了时间序列模式和规则的挖掘算法,并举例说明该算法是有效和可行的。     

时态粒度约束下的时态元素定性关系探讨

针对时态粒度约束下的时态元素之间的定性关系,引入向量空间思想,将时态粒点间的关系转换为向量空间中的运算。提出时态粒点的向量判别方法以比较两个时态粒点的先后关系,通过粒度缩放操作探讨了时态粒区之间的关系、时态粒点与时态粒区之间的定性关系,对时态数据库、时态知识推理、时态数据挖掘等时态应用研究领域起到了良好的基础支持作用。     

Data mining with Temporal Abstractions: learning rules from time series

A large volume of research in temporal data mining is focusing on discovering temporal rules from time-stamped data. The majority of the methods proposed so far have been mainly devoted to the mining of temporal rules which describe relationships between data sequences or instantaneous events and do not consider the presence of complex temporal patterns into the dataset. Such complex patterns, such as trends or up and down behaviors, are often very interesting for the users. In this paper we propose a new kind of temporal association rule and the related extraction algorithm; the learned rules involve complex temporal patterns in both their antecedent and consequent. Within our proposed approach, the user defines a set of complex patterns of interest that constitute the basis for the construction of the temporal rule; such complex patterns are represented and retrieved in the data through the formalism of knowledge-based Temporal Abstractions. An Apriori-like algorithm looks then for meaningful temporal relationships (in particular, precedence temporal relationships) among the complex patterns of interest. The paper presents the results obtained by the rule extraction algorithm on a simulated dataset and on two different datasets related to biomedical applications: the first one concerns the analysis of time series coming from the monitoring of different clinical variables during hemodialysis sessions, while the other one deals with the biological problem of inferring relationships between genes from DNA microarray data.     

基于RIPPER的旋转机械故障诊断知识获取

数据挖掘技术能够从大量、不完全、有噪声、模糊、随机的实际应用数据中,提取隐含在其中的、人们事先不知道的本质的规律。为了有效地发现旋转机械故障诊断过程中的故障征兆知识,引入数据挖掘技术和方法。针对旋转机械,构建了基于重复增量修枝算法RIPPER（Repeated Incremental Pruning to Produce Error Reduction）的故障诊断知识获取系统。通过收集故障现象并整理成由故障征兆、故障类型等组成的故障信息样本,应用RIPPER算法对故障进行分析得到故障诊断规则集文件,实现故障诊断系统知识的获取和自动更新,并能对旋转机械的常见故障进行诊断,验证了算法的合理性。     

Building spatial temporal relation graph of concepts pair using web repository

Mining semantic relations between concepts underlies many fundamental tasks including natural language processing, web mining, information retrieval, and web search. In order to describe the semantic relation between concepts, in this paper, the problem of automatically generating spatial temporal relation graph (STRG) of semantic relation between concepts is studied. The spatial temporal relation graph of semantic relation between concepts includes relation words, relation sentences, relation factor, relation graph, faceted feature, temporal feature, and spatial feature. The proposed method can automatically generate the spatial temporal relation graph (STRG) of semantic relation between concepts, which is different from the manually generated annotation repository such as WordNet and Wikipedia. Moreover, the proposed method does not need any prior knowledge such as ontology or the hierarchical knowledge base such as WordNet. Empirical experiments on real dataset show that the proposed algorithm is effective and accurate.     

数据挖掘技术在高校课堂教学评价中的应用

数据挖掘技术目前在商业、金融业等方面都得到了广泛的应用,而在教育领域应用较少。数据挖掘中的关联规则挖掘能够发现大量数据中项集之间有趣的关联或相关联系,特别是随着大量数据不停地收集和存储,从数据库中挖掘关联规则就越来越有其必要性。文中从滁州学院教师档案数据库提取相关教师的记录,并结合课堂教学质量评估中的实际数据,利用改进的Apriori算法找出教师本身的素质与学生评价结果之间的内在关系。     

医学数据挖掘系统研究——糖尿病并发症流行病学知识发现

针对流行病学研究的特点,论文提出计算机辅助医学数据挖掘系统构架,以糖尿病并发症为研究实例,探讨医学数据的冗余性消除、规范化储存、知识归纳及可视化表达等问题。以天津总医院3022例普查数据为研究对象,尝试解决用计算机实现糖尿病并发症这类定性数据的定量化数据挖掘和知识发现。通过对于43种并发症的定性数据挖掘,可以发现诸如高血脂、冠心病、高血压、脑血管病等具有明显并发倾向的知识规则18条。同时,采用知识树方式和决策树等方法实现知识规则的可视化表达。基于数据挖掘和知识发现计算机辅助医学数据挖掘系统能够对现有病历数据库中数据进行自动分析并且提供有价值医学知识,特别适合流行病学分析和全民健康评估,因此与社区医疗和医院HIS系统结合是未来一个非常现实的发展方向。     

关联规则挖掘与分类规则挖掘的比较研究

关联规则挖掘与分类规则挖掘都是数据挖掘,领域中很重要的技术。本文首先简要介绍了关联规则挖掘和分类规则挖掘的基本知识,主要从挖掘目的、发现规则算法的方法、算法的设计思想等几个方面对它们进行了比较,最后介绍了它们之间的联系。     

基于半空间和GA的关联规则快速挖掘算法

提出了一种利用半空间模型和遗传算法(GA)对关联规则进行快速挖掘的方法。传统关联规则挖掘算法往往受到数据类型、关联规则的实际意义等约束,大大限制了知识获取的能力。而此方法不再受到上述限制的困扰,并且可以挖掘出用户感兴趣的规则,尤其对于大规模样本集的效果也是相当不错的。