数据流挖掘研究

上世纪末，为适应网络监控、入侵检测、情报分析、商业交易管理和分析等应用的要求，数据流技术应运而生。数据流独特的特点，对传统数据的处理方法带来了很大的挑战。介绍了数据流的有关概念及数据流挖掘的特点，讨论了数据流挖掘的研究现状。最后，举例说明了数据流挖掘的应用，并展望了数据流挖掘未来的研究方向。     

数据流的频繁模式挖掘算法浅析

介绍了数据流的定义和特点及数据流频繁模式的基本概念。针对数据流的特性,讨论分析了目前国内外数据流频繁模式挖掘算法、算法特性及应用情况,最后展望了数据流频繁模式挖掘的进一步研究工作。     

数据流挖掘方法研究

由于数据流不同于传统静态数据的特点,对其进行有效的分析和挖掘遇到了极大的挑战。本文对近年来数据流挖掘方面的进展进行了综述,介绍数据流的基本概念、数据流模型和对数据流的概要描述,总结数据流挖掘中常用的算法,最后结合其在不同领域中的应用对数据流挖掘的意义进行分析。     

数据流挖掘分类技术综述

数据流挖掘作为从连续不断的数据流中挖掘有用信息的技术,近年来正成为数据挖掘领域的研究热点,并有着广泛的应用前景.数据流具有数据持续到达、到达速度快、数据规模巨大等特点,因此需要新颖的算法来解决这些问题.而数据流挖掘的分类技术更是当前的研究热点.综述了当前国际上关于数据流挖掘分类算法的研究现状,并从数据平稳分布和带概念漂移两个方面对这些方法进行了系统的介绍与分析,最后对数据流挖掘分类技术当前所面临的问题和发展趋势进行了总结和展望.     

数据流管理和挖掘技术探析

数据流管理和挖掘技术是数据库领域的新研究方向之一。概述了数据库技术的发展趋势以及数据流的概念、特点、体系结构、应用领域,分析了数据流概要数据结构的构造问题和数据流的连续近似查询技术,最后介绍了数据流挖掘技术。旨在描述数据流管理和挖掘技术的发展概况,为进一步的研究提供有益的借鉴。     

挖掘数据流频繁模式的相关技术和算法研究综述

数据流本身的特点使得静态挖掘方法不再满足要求。国内外学者已提出许多新的挖掘数据流频繁模式的方法和技术。对这些技术和算法进行了综述。首先介绍数据流的概念和特点,分析国内外的研究现状,总结了数据流中挖掘频繁模式的特点,并列出挖掘方法的常用技术和基于这些技术的代表性算法,最后讨论了将来的研究方向。     

数据流挖掘技术研究

在当今的网络监控、电信数据管理、传感器数据监控等应用中,数据采取的是多维的、连续的、快速的、随时间变化的流式数据的形式,对数据的访问也是多次和连续的,并要求即时的响应.数据流独特的特点,对传统数据的处理方法带来很大的挑战.数据流应用的出现,带动了相关技术的研究,其中包括数据流挖掘的研究.文中介绍了数据流的基本概 念,讨论了数据流挖掘的研究现状及相关技术,包括数据流的介绍、流行的数据流处理技术和数据挖掘中的相关算法.     

浅论数据流挖掘

本文主要讨论了数据流挖掘的现状及发展,简要地介绍了数据流挖掘的概念,详细地介绍了数据流挖掘的特点及其数据模型的特点,介绍了几种常用数据流挖掘流挖掘方法。     

数据流挖掘技术及其在仿真中的应用

随着仿真系统复杂程度的增加和规模的增大,仿真时间越来越长,仿真所产生的数据量越来越大,使得仿真数据具有数据流的特性,因此可以采用数据流挖掘技术处理仿真数据.综述了数据流和数据流挖掘技术的主要特点;提出了基于数据流挖掘技术的仿真应用框架;设计了通用数据流挖掘成员,以便能够快速将数据流挖掘算法集成到基于HLA体系结构的仿真系统中,并以导弹突防仿真系统为例介绍了所设计的通用数据流关联规则挖掘成员.     

数据流挖掘技术研究

在当今的网络监控、电信数据管理、传感器数据监控等应用中，数据采取的是多维的、连续的、快速的、随时间变化的流式数据的形式，对数据的访问也是多次和连续的，并要求即时的响应。数据流独特的特点，对传统数据的处理方法带来很大的挑战。数据流应用的出现，带动了相关技术的研究，其中包括数据流挖掘的研究。文中介绍了数据流的基本概念，讨论了数据流挖掘的研究现状及相关技术，包括数据流的介绍、流行的数据流处理技术和数据挖掘中的相关算法。     

基于数据流的移动数据挖掘研究综述*

无线网络和移动设备的应用为我们带来巨大的便利,可以随时随地获得信息,同时它也引发了对高效数据流分析工具的需求。移动数据挖掘是在普适环境下的数据流挖掘,从连续的数据流中发现知识。讨论了数据流、数据流管理系统和移动数据挖掘以及它们的特点,介绍了该领域的一些研究成果,突出了面临的挑战和一些相应的策略,并对这些策略进行了比较,最后展望了这一领域的研究前景。     

Detection and removal of infrequent behavior from event streams of business processes

Process mining aims at gaining insights into business processes by analyzing the event data that is generated and recorded during process execution. The vast majority of existing process mining techniques works offline, i.e. using static, historical data, stored in event logs. Recently, the notion of online process mining has emerged, in which techniques are applied on live event streams, i.e. as the process executions unfold. Analyzing event streams allows us to gain instant insights into business processes. However, most online process mining techniques assume the input stream to be completely free of noise and other anomalous behavior. Hence, applying these techniques to real data leads to results of inferior quality. In this paper, we propose an event processor that enables us to filter out infrequent behavior from live event streams. Our experiments show that we are able to effectively filter out events from the input stream and, as such, improve online process mining results.     

数据流频繁模式挖掘综述

一些先进应用如欺诈检测和趋势学习等带来了数据流频繁模式挖掘的发展。不同于静态数据,数据流挖掘面临着时空约束和项集组合爆炸等问题。对已有数据流频繁模式挖掘算法进行综述并对经典和最新算法进行分析。按照模式集合的完整程度进行分类,数据流中频繁模式分为全集模式和压缩模式。压缩模式主要包括闭合模式、最大模式、top-k模式以及三者的组合模式。不同之处是闭合模式是无损压缩的,而其他模式是有损压缩的。为了得到有趣的频繁模式,可以挖掘基于用户约束的模式。为了处理数据流中的新近事务,将算法分为基于窗口模型和基于衰减模型的方法。数据流中模式挖掘常见的还包含序列模式和高效用模式,对经典和最新算法进行介绍。最后给出了数据流模式挖掘的下一步工作。     

Interactive mining of high utility patterns over data streams

High utility pattern (HUP) mining over data streams has become a challenging research issue in data mining. When a data stream flows through, the old information may not be interesting in the current time period. Therefore, incremental HUP mining is necessary over data streams. Even though some methods have been proposed to discover recent HUPs by using a sliding window, they suffer from the level-wise candidate generation-and-test problem. Hence, they need a large amount of execution time and memory. Moreover, their data structures are not suitable for interactive mining. To solve these problems of the existing algorithms, in this paper, we propose a novel tree structure, called HUS-tree (high utility stream tree) and a new algorithm, called HUPMS (high utility pattern mining over stream data) for incremental and interactive HUP mining over data streams with a sliding window. By capturing the important information of stream data into an HUS-tree, our HUPMS algorithm can mine all the HUPs in the current window with a pattern growth approach. Furthermore, HUS-tree is very efficient for interactive mining. Extensive performance analyses show that our algorithm is very efficient for incremental and interactive HUP mining over data streams and significantly outperforms the existing sliding window-based HUP mining algorithms.     

Mining data streams with concept drifts using genetic algorithm

Recent research shows that rule based models perform well while classifying large data sets such as data streams with concept drifts. A genetic algorithm is a strong rule based classification algorithm which is used only for mining static small data sets. If the genetic algorithm can be made scalable and adaptable by reducing its I/O intensity, it will become an efficient and effective tool for mining large data sets like data streams. In this paper a scalable and adaptable online genetic algorithm is proposed to mine classification rules for the data streams with concept drifts. Since the data streams are generated continuously in a rapid rate, the proposed method does not use a fixed static data set for fitness calculation. Instead, it extracts a small snapshot of the training example from the current part of data stream whenever data is required for the fitness calculation. The proposed method also builds rules for all the classes separately in a parallel independent iterative manner. This makes the proposed method scalable to the data streams and also adaptable to the concept drifts that occur in the data stream in a fast and more natural way without storing the whole stream or a part of the stream in a compressed form as done by the other rule based algorithms. The results of the proposed method are comparable with the other standard methods which are used for mining the data streams.     

Mining frequent itemsets in data streams using the weighted sliding window model

In recent years, data stream mining has become an important research topic. With the emergence of new applications, the data we process are not again static, but the continuous dynamic data stream. Examples include network traffic analysis, Web click stream mining, network intrusion detection, and on-line transaction analysis. In this paper, we propose a new framework for data stream mining, called the weighted sliding window model. The proposed model allows the user to specify the number of windows for mining, the size of a window, and the weight for each window. Thus users can specify a higher weight to a more significant data section, which will make the mining result closer to user’s requirements. Based on the weighted sliding window model, we propose a single pass algorithm, called WSW, to efficiently discover all the frequent itemsets from data streams. By analyzing data characteristics, an improved algorithm, called WSW-Imp, is developed to further reduce the time of deciding whether a candidate itemset is frequent or not. Empirical results show that WSW-Imp outperforms WSW under the weighted sliding window model.     

Ensemble learning for data stream analysis: A survey

In many applications of information systems learning algorithms have to act in dynamic environments where data are collected in the form of transient data streams. Compared to static data mining, processing streams imposes new computational requirements for algorithms to incrementally process incoming examples while using limited memory and time. Furthermore, due to the non-stationary characteristics of streaming data, prediction models are often also required to adapt to concept drifts. Out of several new proposed stream algorithms, ensembles play an important role, in particular for non-stationary environments. This paper surveys research on ensembles for data stream classification as well as regression tasks. Besides presenting a comprehensive spectrum of ensemble approaches for data streams, we also discuss advanced learning concepts such as imbalanced data streams, novelty detection, active and semi-supervised learning, complex data representations and structured outputs. The paper concludes with a discussion of open research problems and lines of future research.