论文学文本的对话性

文学文本是主体性的存在,具有潜在的对话性,它从多种层次和角度持续地发出自己的声音。文学文本的对话性是由它的载体、结构和内容这三个要素的对话性所决定的。文学文本的意义正是在与读者不断深入的对话中实现的。     

基于Web服务架构的数字图书馆信息检索系统的设计与实现

本文通过分析图书馆信息检索的现状，利用Web服务强大的信息交换能力，设计了一个基于Web服务架构的信息检索系统．使用该系统可以最终解决图书馆长期以来资源共建共享的困难．     

科技资源图像检索技术研究与实现

科技资源具有海量、复杂、异构、地理分布广的特点。为了高效查找和使用科技资源的图像,综合运用TB IR(基于文本的图像检索)和CB IR(基于内容的图像检索)共同检索科技资源图像,设计了科技资源图像检索系统,并对系统中的图像分割、特征提取和相似度度量3种关键技术进行了研究。     

一种基于智能Agent的用户个性化信息检索系统模型

针对当前信息检索工具缺乏对知识的理解和处理能力,提出了一种基于智能Agent的用户个性化信息检索系统模型,通过多个Agent的协调工作为用户提供个性化服务。描述了该模型的系统结构及各功能模块的实现方法,分析了系统模型的工作流程,部分解决了信息检索中的文档相关性计算、搜索引擎的调度算法、数据库的构建等技术问题。     

Determination of the optical thickness and effective particle radius of clouds from transmitted solar radiation measurements

A method is presented for determining the optical thickness (τc) and effective particle radius (re) of stratiform cloud layers from transmitted solar radiation measurements. A detailed study shows that the cloud optical thickness and effective particle radius of water clouds can be determined from transmission function measurements at 0.75 and 2.13 μm, provided that the scaled optical thickness τ′0.75>1 and re>5 μm. The wavelengths adopted by our study are similar to the channels of the moderate resolution imaging spectrometer (MODIS). The proposed method is invalid for optically thin clouds since transmission at 2.13 μm is less sensitive to re. The retrieval errors of τ′0.75 and re monotonically decrease with increasing τc. For clouds having τ′0.75≥2, the retrieval errors of τ′0.75 and re are below 10% and 20%, respectively. Transmissions at 0.75 and 1.65 μm can also be used to retrieve τc and re.     

Blurred Defocused Image Restoration Based on FRFT

A technique for restoring the blurred image resulted from defocusing of the lens is proposed in this paper, which is based on fractional Fourier transform （FRFT）.The FRFT, as a powerful tool for the analysis of time-varying signals, is closely connected with the optical imaging system. FRFT also can describe optical imaging process just like Fresnel diffractions, so a defocused imaging model based on FRFT is established to explain the blur phenomena of defocusing image. The defocused imaging model is greatly different from the traditional point spread function （PSF） model, and enables to uncover the blur nature of non-focus image. Then, an image restoration method using the novel model is proposed to handle the blurred defocused image. The method adopted a new iterative phase retrieval approach which can approximately estimate phase signals from intensity signals of a single defocused image by means of FRFT. Restoring image may acquire sharp image by implementing inverse FRFT on complex image signal made from the estimated phase signals and intensity signals. Experimental results demonstrate that the method is effective in restoring blurred defocused image.     

Automatic Question Answering from Web Documents

A passage retrieval strategy for web-based question answering （QA） systems is proposed in our QA system. It firstly analyzes the question based on semantic patterns to obtain its syntactic and semantic information and then form initial queries. The queries are used to retrieve documents from the World Wide Web （WWW） using the Google search engine. The queries are then rewritten to form queries for passage retrieval in order to improve the precision. The relations between keywords in the question are employed in our query rewrite method. The experimental result on the question set of the TREC-2003 passage task shows that our system performs well for factoid questions.     

Harmonic Retrieval Embedded in Hybrid Colored Noise: a Novel Pisarenko Method Based on Cross-high-order Cumulant

Spectral estimation method is an effective method in the case of parameter estimation of sinusoid signal in noises.It always applies cross-spectral estimation theory and high-order self-spectral estimation methods up to now.Yule-Walker equation based on cross-fourth-order cumulant is developed and Pisarenko method is provided in this paper.Simulation results show that the method is effective to retrieve sinusoid signal frequencies from hybrid colored noises and has good performance.     

大规模互联网图像检索与模式挖掘

在互联网时代，爆炸式增长的数字图像不仅给图像检索带来巨大的技术挑战，同时也带来了很多机遇和研究问题的新思路．本文简单回顾了图像检索的三个阶段的研究历史．以及在此过程中数据量的增多给图像检索带来的影响，并对作为关键问题的特征提取方面的研究进行了深入的分析．本文尤其指出视觉模式挖掘是寻找中层特征表示并缩小语义鸿沟的重要研究方向，并根据视觉模式的表征粒度将其分为五种类别分别进行了介绍，从中可以看到大数据对于视觉模式挖掘的重要作用．     

语篇衔接理论研究综述

由Halliday和Hasan所提出的语篇衔接理论涉及指称、替代、省略、连接和词汇衔接五大范畴。自二人合著的《英语中的衔接》一书出版以来，国内外学者围绕衔接和连贯进行了不同层次的研究，从不同角度、以不同方法对语篇衔接理论进行探讨，促使其得以不断发展和完善。