基于用户偏好的垂直搜索算法

提出并研究、实现了基于用户偏好的垂直搜索算法(PVSA)。以领域特征为基本出发点,PVSA借助领域主题偏好向量、领域元数据权重因子、检索名词差异化、行业词典库更新等4项策略,有效地挖掘、表征用户的领域个性化偏好,以此为基础构建基于用户偏好的垂直搜索算法。实验结果表明了PVSA算法的有效性和可行性。     

术语“AIDS(艾滋病)”全称应用考察

本文考察表明,部分汉语辞书未能规范应用AIDS全称。辞书确定术语规范形式应根据国家标准、政府的法规性规定、科技界的应用通例、权威或通行的汉语辞书的模式进行;语文辞书中的术语规范应用在词汇、概念、词条3个层面上分别要求。     

Concurrent analogue fault simulation,the equation formulation aspect

Fault simulation is an essential tool for developing test patterns for circuits. Because the potential number of faults in a circuit is potentially very large, computational efficiency is an important consideration. In the digital domain, concurrent fault simulation is well‐established as an efficient tool. For analogue circuits, fault simulation is often performed by repeated insertion of possible faults and resimulation of the circuit. Consequently, methods for efficient concurrent analogue fault simulation are attracting attention. A review of existing methods of concurrent analogue fault simulation shows that most are based on a similar fundamental perturbation of the original fault‐free circuit equations, although the methods differ in the procedure applied after the circuit equations are formulated. We develop here a comprehensive set of element stamps, describing faulty elements, enabling effective and routine equation formulation for faulty circuits. These may be used no matter what method of fault simulation is later applied. These stamps are used in a new technique for concurrent analogue fault simulation, based on modified nodal analysis. A significant improvement in efficiency, compared with other methods, is demonstrated. Copyright © 2004 John Wiley & Sons, Ltd.     

Practical compressed string dictionaries

The need to store and query a set of strings – a string dictionary – arises in many kinds of applications. While classically these string dictionaries have accounted for a small share of the total space budget (e.g., in Natural Language Processing or when indexing text collections), recent applications in Web engines, Semantic Web (RDF) graphs, Bioinformatics, and many others handle very large string dictionaries, whose size is a significant fraction of the whole data. In these cases, string dictionary management is a scalability issue by itself. This paper focuses on the problem of managing large static string dictionaries in compressed main memory space. We revisit classical solutions for string dictionaries like hashing, tries, and front-coding, and improve them by using compression techniques. We also introduce some novel string dictionary representations built on top of recent advances in succinct data structures and full-text indexes. All these structures are empirically compared on a heterogeneous testbed formed by real-world string dictionaries. We show that the compressed representations may use as little as 5% of the original dictionary size, while supporting lookup operations within a few microseconds. These numbers outperform the state-of-the-art space/time tradeoffs in many cases. Furthermore, we enhance some representations to provide prefix- and substring-based searches, which also perform competitively. The results show that compressed string dictionaries are a useful building block for various data-intensive applications in different domains.     

Integrating MultiWordNet with Italian Sign Language lexical resources

A novel Italian Sign Language MultiWordNet (LMWN), which integrates the MultiWordNet (MWN) lexical database with the Italian Sign Language (LIS), is presented in this paper. The approach relies on LIS lexical resources which support and help to search for Italian lemmas in the database and display corresponding LIS signs. The lexical frequency analysis of the lexicon and some newly created signs approved by expert LIS signers are also discussed. The larger MWN database helps to enrich the variety and comprehensiveness of the lexicon. We also describe the approach which links the Italian lemmas and LIS signs to extract and display bilingual information from the collected lexicon and the semantic relationships of LIS Signs with MWN. The users can view the meanings of almost one fourth of the lemmas of MWN in LIS.     

从词典编译看英文语言学术语汉译的基本原则

文章重点分析了国内现有3本编译类语言学词典的优点和不足。3本词典的优点是编排形式渐趋合理,不断补充新词并增加原有词条的最新用法,及时纠正不当译名;缺点是某些译名不够准确,同时译名缺乏系统性。在此基础上提出了英文语言学术语汉译的5个原则：准确性原则、全面性原则、一致性原则、互参性原则和区别性原则。     

基于两级字典与分频带字典的图像超分辨率算法

常规基于稀疏表示的超分辨率算法使用一级高低分辨字典重构图像, 恢复细节信息不充分. 本文利用两级字典恢复尽可能多的细节信息; 然后构造联合低频字典、中频字典、高频字典的分频带字典, 利用图像低频、中频、高频三者之间的预测关系, 恢复图像中的高频信息. 利用图像的非局部相似性, 将其与迭代反向投影算法相结合, 进行图像的后处理. 实验结果表明, 与其他几种基于学习的算法相比, 本算法无论是在峰值信噪比、结构相似性指标, 还是视觉效果上都有显著的提高.     

基于散列辞典的蛋白质二级结构预测方法

提出一种易于修改的蛋白质二级结构预测算法。以蛋白质数据银行中PDB文本数据作为数据源,提取所有蛋白质氨基酸序列并以此建立样本数据库,然后针对α-螺旋、β-折叠分别利用基于散列辞典的不同改进方法编程实现蛋白质二级结构序列片段预测,在预测过程中,随机抽取68421个蛋白质中部分样本作为测试集,对未知序列根据建立的散列辞典中的片段使用正向最大匹配分词法进行切分对比。从实验结果来看,对未知序列片段预测的准确度达到了83．9％,而且能够较好地体现片段之间的连接顺序。