基于遗传算法的时间序列中频繁结构模式发现研究

本文提出了一个基于小生境遗传算法和模式缓存的时间序列中频繁结构模式的发现算法，该算法具有轻便、灵活、可扩放性好的特点，可根据实际情况合理配置计算时间和所占用的内存资源，并可实现挖掘结果的实时动态更新输出，在实际时间序列数据上的实验证明了该算法的有效性。     

一种基于滑动窗口模型的数据流加权频繁模式挖掘方法

相对于传统的频繁模式挖掘,加权频繁模式挖掘能发现更有价值的模式信息.针对数据流中的数据只能一次扫描,本文提出了一种基于滑动窗口模型的数据流加权频繁模式挖掘方法WFP-SW(Sliding Window based Weighted Frequent Pattern minig),算法采用WE-tree(Weighted Enumeration Tree)存储模式和事务信息,利用虚权支持度维持模式的向下闭合特性,同时获取临界频繁模式.对临界频繁模式进一步计算其加权支持度获取加权频繁模式,使得计算更新模式更加便捷.实验结果显示算法具有较高的挖掘效率并且所需的内存更少.     

概率频繁模式挖掘算法研究综述

本文围绕图集中的频繁子图挖掘算法、单图中的频繁子图挖掘算法两个方面展开讨论,对概率频繁模式挖掘算法进行了研究以及综述,并在此基础上提出了一些笔者自己的见解,希望能够对今后的概率频率模式挖掘算法的研究提供一些理论建议。     

频繁子图挖掘研究综述

归纳了频繁子图挖掘方法的处理流程,分析评价了频繁子图挖掘的典型算法:广度优先搜索和深度优先搜索的频繁子图挖掘算法,概述了频繁子图挖掘研究的平台--图模型及其产生器,并对频繁子图挖掘方法未来研究方向进行了展望.     

FSP:一种基于图论的频繁结构模式挖掘算法

研究在图集中挖掘频繁结构模式的方法，并提出了一种发现频繁结构的新算法FSP（Frequent Structure Pattem Mining），通过在图中建立了一种新的字典顺序，并把每个图映射成唯一的最小DFS编码作为图的规范形式，从而把图转换成一个序列。基于这种字典顺序，FSP算法不需要生成候选，采用深度优先搜索策略挖掘频繁连通子图。试验结果显示，FSP算法在性能上优于以前的算法。     

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．     

基于数据挖掘技术的软件缺陷检测方法研究

针对经典频繁子图挖掘算法FFSM(Fast Frequent Subgraph Mining)无法处理有向多重图、无法得到有向频繁子图和大量的虚假警报的缺点,在其基础上提出一种新的频繁子挖掘算法HFFSM(Higher-performance Fast Frequent Subgraph Mining)。通过实验对比分析HFFSM和FFSM表明,HFFSM算法能够很好地处理有向多重图并输出有向频繁子图,并且减少了算法应用时的虚假警报,在算法效率上略有提高,而边的方向上的改进大大提高了算法的整体表现和实用性。     

多模式匹配算法研究和优化

模式匹配在网络安全领域有着重要的应用,随着网络环境的日益复杂,模式集合也随之增加.如何高效处理千万模式集下的字符串匹配成为网络安全的瓶颈之一.本文针对多模式匹配算法AC算法和WM算法进行了研究,采用了新型基于层次扫描和子节点数目搜索的双数组AC算法;从hash函数的选取和模式串的Tree树存储对WM算法进行了优化.能有效减少系统的内存占用,提高匹配效率.     

数据流中的频繁项集挖掘

频繁模式挖掘是数据挖掘的精髓,并且在上个世纪被广泛研究.概述了数据流频繁模式挖掘的技术发展水平和发展背景.然后给出一些概念定义,就目前经典的数据流频繁模式算法作了分析,并在此基础上总结了前人的方法理论,采用混合的方法,扩展了新的算法——FLY.最后,总结分析新的算法,并与前人算法在内存消耗和准确性方面进行了比较.     

移动通信用户时空行为分析算法研究及系统实现

为了挖掘移动用户行为，提出了基于密度聚类的移动用户热点区域识别算法及融合加权频繁模式（Frequent Pattern,FP）树和最长公共子序列（Longest Common Subsequence,LCSS）算法的移动用户出行频繁轨迹模式提取方法。首先说明与思路相关的概念，其次采用密度聚类方法来识别城市的热点区域，最后融合加权FP树和LCSS算法来提取移动用户出行轨迹模式，并对算法在工程中的应用路径及应用效果进行了说明。     

Multimedia Corpus of In-Car Speech Communication

An ongoing project for constructing a multimedia corpus of dialogues under the driving condition is reported. More than 500 subjects have been enrolled in this corpus development and more than 2 gigabytes of signals have been collected during approximately 60 minutes of driving per subject. Twelve microphones and three video cameras are installed in a car to obtain audio and video data. In addition, five signals regarding car control and the location of the car provided by the Global Positioning System (GPS) are recorded. All signals are simultaneously recorded directly onto the hard disk of the PCs onboard the specially designed data collection vehicle (DCV). The in-car dialogues are initiated by a human operator, an automatic speech recognition (ASR) system and a wizard of OZ (WOZ) system so as to collect as many speech disfluencies as possible. In addition to the details of data collection, in this paper, preliminary results on intermedia signal conversion are described as an example of the corpus-based in-car speech signal processing research.     

TV gets personal [personal video recorders]

The personal video recorder (PVR)-a TV recorder that records on a computer hard disc as opposed to tape-has evolved as a direct consequence of the development of the PC as a low-cost, high-performance consumer product. Sharing many features with a PC with tens of gigabytes of hard disc storage, the PVR has the potential to revolutionise the way broadcasters schedule TV programmes and the way viewers watch them. Making a PVR an attractive product needs more than the convergence of TV and computer technology. In particular, an effective programme guide service, downloaded either with the TV signal or via the phone network, is crucial in establishing the PVR's attractiveness to viewers. The stored guide data simplifies programme selection and recording, and offers new features like automatic recording of all episodes of a series, even if they're not all at the same time each week. The authors describe how the introduction of the PVR will transforming viewing habits. The systems available are described and possible developments in PVRs are discussed     

Technical software [Technology 2000 analysis and forecast]

Twenty years ago, only a handful of visionaries could have predicted that powerful software born of supercomputing would butt its way into almost every desktop PC. Few foresaw the scale of data that would be manipulated or the complexity of the tasks that would be performed by software tools costing a few hundred dollars. But now, all developers of technical software take it as given that users may need to process gigabytes of data drawn from a combination of sources: instrument output; archived data; and publicly available materials, such as census data downloaded from the Internet. In this paper, the author argues that, in a sophisticated marketplace, the success of those developers hinges on equipping users to gain ever swifter insight into many reams of data     

车载网络中安全有效分布式的假名生成

提出了一种RSU协助的分布式假名生成方法。首先,车辆用户生成自己的临时公钥,当经过RSU时,由RSU对其临时公钥进行盲签名;然后,车辆得到RSU对自己临时公钥的签名,并将该签名与临时公钥一起构成车辆的一个假名（临时公钥+RSU对临时公钥的签名）,通过该假名与周围节点进行通信。本方法的优势在于：一方面RSU能够分担VANET中认证中心（CA）的负担,有效地提高了系统的效率、增强了系统的可扩展性;另一方面,由于生成车辆假名的私钥在RSU中,而不是在车辆中,因此增加了攻击者提取系统密钥的难度,从而提高了系统的安全性。     

Shape-based normalization of the corpus callosum for DTI connectivity analysis

The continuous medial representation (cm-rep) is an approach that makes it possible to model, normalize, and analyze anatomical structures on the basis of medial geometry. Having recently presented a partial differential equation (PDE)-based approach for 3-D cm-rep modeling [1], here we present an equivalent 2-D approach that involves solving an ordinary differential equation. This paper derives a closed form solution of this equation and shows how Pythagorean hodograph curves can be used to express the solution as a piecewise polynomial function, allowing efficient and robust medial modeling. The utility of the approach in medical image analysis is demonstrated by applying it to the problem of shape-based normalization of the midsagittal section of the corpus callosum. Using diffusion tensor tractography, we show that shape-based normalization aligns subregions of the corpus callosum, defined by connectivity, more accurately than normalization based on volumetric registration. Furthermore, shape-based normalization helps increase the statistical power of group analysis in an experiment where features derived from diffusion tensor tractography are compared between two cohorts. These results suggest that cm-rep is an appropriate tool for normalizing the corpus callosum in white matter studies.     

A System Framework for Map Air Update Navigation Service

The quality of navigation service is determined by the accuracy of the available data. For existing navigation services, a full map update is provided in order to keep the map data of mobile devices current. As content and services of mobile devices have recently been diversifying, the size of map data managed in mobile devices has increased, reaching several gigabytes in size. It generally takes tens of minutes to write several gigabytes of data into mobile device storage. For traditional navigation systems, a complicated storage structure called a physical storage format (PSF) is used to assure maximum processing performance of map data in mobile devices within limited resources. Consequently, even though modified navigation map data actually affects only a portion of a map, the full map data is updated because partial updates are not possible. In this paper, a navigation system is studied to solve this difficult partial map update problem. The map air update navigation system, which is the result of this study, provides real‐time partial map updating using wireless communications.     

一种新词自动提取方法

当前网络语料会不断出现大量新词已经成为一种普遍的趋势,这里面包含大量网友创造的新词,以及一些社会热点形成的新词。同时社交网络产生的社交性语料存在大量口语化、简称和随意的表达。这些都对中文分词的准确性造成了困扰。本文提出了一种新词自动提取方法,旨在能准确快速地在特定的语料里提取新词,生成特定领域词典,更准确地对网络语料进行中文分词。通过从语料中提取候选词,计算候选词的支持度和置信度,通过阈值刷选出新词,从而实现从海量文本中准确且快速的提取新词。     

一种短波通信可靠多播群组管理方法

针对异步短波单层可靠多播网络群组管理中临时节点加入或退出时网络处理时延较 长的问题,提出了一种分层可靠多播网络群组管理方法。通过设置群首节点来减少该临时节 点与网络内部成员的交互次数。理论分析和仿真结果表明,该方法较单层可靠多播网络群组 管理方法,具有网络对该临时节点处理时延小、群组管理复杂度低等优点,其应用前景广阔 。     

Implantable defibrillator with high-output pacing function afterdefibrillation

An experimental implantable defibrillator with a temporary pacing function was developed. The pacing function was activated after defibrillation to work as a high-output ventricular-demand pacemaker. The developed system was tested in animal experiments involving anesthesized and mechanically ventilated mongrel dogs. In the animal experiments, fibrillation was electrically induced, and the automatic defibrillation and pacing function were confirmed. After defibrillation, it was possible to continue the fixed-rate pacing for more than three minutes     

微波裸芯片临时封装夹具微波信号传输的优化

微波传输线是微波系统的重要组成部分。随着微波系统向高频化方向发展,传输线中的不连续带来的信号完整性问题越发凸显并受到广泛的关注。针对微波裸芯片临时封装夹具系统,设计了适合2~6 GHz频段的微波传输线,通过三维电磁仿真软件(HFSS)对传输线的传输性能进行了仿真验证;并由先进设计系统(ADS)软件提取了临时封装夹具中微波传输路径的等效RLC电路参数模型。最终得到的传输结构S11小于-15 dB,S21大于-1 dB,符合良好匹配传输线的要求。