在线旅游业务中Web页面主体块提取方法研究

Web信息提取是在线旅游业务的重要技术。页面的主体语义块集中了最主要的信息量,它的正确提取是Web信息提取的基础。本文在对现有页面分割方案总结的基础上,提出了结合机器学习方法的Web页面主体语义块节点识别算法,并基于启发式规则对正结果集进行后续的校验,以定位最佳的主体语义块节点。通过实验,本文提出的方案达到了比较理想的准确率。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Parallel block tridiagonalization of real symmetric matrices

Two parallel block tridiagonalization algorithms and implementations for dense real symmetric matrices are presented. Block tridiagonalization is a critical pre-processing step for the block tridiagonal divide-and-conquer algorithm for computing eigensystems and is useful for many algorithms desiring the efficiencies of block structure in matrices. For an “effectively” sparse matrix, which frequently results from applications with strong locality properties, a heuristic parallel algorithm is used to transform it into a block tridiagonal matrix such that the eigenvalue errors remain bounded by some prescribed accuracy tolerance. For a dense matrix without any usable structure, orthogonal transformations are used to reduce it to block tridiagonal form using mostly level 3 BLAS operations. Numerical experiments show that block tridiagonal structure obtained from this algorithm directly affects the computational complexity of the parallel block tridiagonal divide-and-conquer eigensolver. Reduction to block tridiagonal form provides significantly lower execution times, as well as memory traffic and communication cost, over the traditional reduction to tridiagonal form for eigensystem computations.     

A multi-agent legal recommender system

Infonorma is a multi-agent system that provides its users with recommendations of legal normative instruments they might be interested in. The Filter agent of Infonorma classifies normative instruments represented as Semantic Web documents into legal branches and performs content-based similarity analysis. This agent, as well as the entire Infonorma system, was modeled under the guidelines of MAAEM, a software development methodology for multi-agent application engineering. This article describes the Infonorma requirements specification, the architectural design solution for those requirements, the detailed design of the Filter agent and the implementation model of Infonorma, according to the guidelines of the MAAEM methodology.     

A flexible semantic inference methodology to reason about user preferences in knowledge-based recommender systems

Recommender systems arose with the goal of helping users search in overloaded information domains (like e-commerce, e-learning or Digital TV). These tools automatically select items (commercial products, educational courses, TV programs, etc.) that may be appealing to each user taking into account his/her personal preferences. The personalization strategies used to compare these preferences with the available items suffer from well-known deficiencies that reduce the quality of the recommendations. Most of the limitations arise from using syntactic matching techniques because they miss a lot of useful knowledge during the recommendation process. In this paper, we propose a personalization strategy that overcomes these drawbacks by applying inference techniques borrowed from the Semantic Web. Our approach reasons about the semantics of items and user preferences to discover complex associations between them. These semantic associations provide additional knowledge about the user preferences, and permit the recommender system to compare them with the available items in a more effective way. The proposed strategy is flexible enough to be applied in many recommender systems, regardless of their application domain. Here, we illustrate its use in AVATAR, a tool that selects appealing audiovisual programs from among the myriad available in Digital TV.     

基于本体的城市遥感影像语义模型

在快速的城市化进程中,遥感技术可以为城市土地利用变化提供直观、准确、同步的信息。本体是对概念化的明确描述和说明,更接近于认知模型,易于理解和共享;同时又能以计算机可操作的形式化语言明确表达目标领域的概念体系及其蕴含的语义。因此,在分析和借鉴现有相关研究的基础上,将本体、语义思想引入到遥感影像表达,建立了基于本体的城市遥感影像解译应用语义模型和解译框架,应用此框架将有助于提高城市遥感影像解译的精度与效率,对推动遥感技术在城市相关领域中的应用有着积极的意义。     

一种基于DOM的Web文档主题划分方法

主题划分是多主题文档自动摘要中的一个重要问题,提出了一种以网页结构为指导,利用页面对应DOM树中节点的自然分割功能以及相邻边界节点语义相似度的比较进行网页主题划分的方法.实验结果表明该方法具有较高的划分准确率,在此基础上抽取的网页摘要可显著增加文摘内容对原文的覆盖率、有效解决Web文档摘要分布不平衡问题.     

机械臂视觉伺服系统中的高精度实时特征提取

以机械臂视觉伺服系统为背景,立体视觉所需要的特征点为目标,提出一种基于颜色块的实时特征提取方法．特征点的定位分为粗定位和精定位两个过程,粗定位用来跟踪目标颜色块,精定位在粗定位的基础上,切出小图像并提取目标轮廓,利用犓犔变换对轮廓点进行分类,并通过最小二乘法对边缘点进行拟合．根据直线方程计算顶点的亚像素精度坐标,为下一步的目标位姿测量提供基础．实验结果验证了该方法的有效性．     

基于DSP的3DES加密系统的设计与实现

针对目前通用计算机实现的加密算法速度有限,而专用加密芯片的开发成本较高、开发周期相对较长的现状,采用数字信号处理器(DSP)设计了一种新型的加密系统;该系统采用TI公司高速浮点型DSP芯片TMS320C6713实现了3DES(Triple Data EncryptionStandard)加密算法;并采用CY7C68001 USB2.0接口芯片完成了DSP与PC的通讯;实验结果表明,该加密系统能高速可靠地运行,在该系统的基础上可以扩展成实时数据加密系统。     

The Use of Context-Aware Policies and Ontologies to Facilitate Business-Aware Network Management

The purpose of autonomic networking is to manage the business and technical complexity of networked components and systems. However, existing network management data has no link to business concepts. This makes it very difficult to ensure that services offered by the network are meeting business objectives. This paper describes a novel context-aware policy model that uses a combination of modeled and ontological data to determine the current context, which policies are applicable to that context, and what services and resources should be offered to which users and applications.