基于Lucene的全文搜索引擎的设计与实现

一、引言搜索引擎是指根据一定的策略、运用特定的计算机程序从互联网上搜集信息,在对信息进行组织和处理后,为用户提供检索服务,将用户检索相关的信息展示给用户的系统。搜索引擎可分为全文索引、目录索引、元搜索引擎、垂直搜索引擎等。全文搜索引擎是目前广泛应用的主流搜索引擎,国外代表有Google,国内则有百度。     

搜索引擎检索技术与检索效果探析

搜索引擎是网络信息查找的主要检索工具,而搜索引擎利用的关键,主要取决于其检索技术,检索效果的了解和掌握。本文主要对搜索引擎的检索技术、检索效果进行了分析和总结,以便使用户更好地利用搜索引擎来查询和获取所需信息。     

基于用户偏好的智能数据源选择

当前搜索引擎用户个性化的研究是搜索引擎优化的一个研究分支.当前检索模型的主要弊端就是搜索引擎用户提供的信息很少.目前主要借助于用户在和元搜索引擎交互的过程中提供的隐反馈信息对成员搜索引擎的数据源选择算法进行优化,利用语言模型对用户检索行为建模,用户与元搜索引擎交互的过程中动态更新用户行为模型,自适应的满足不同检索动机的用户的信息需求.     

网络环境下的信息检索

搜索引擎是帮助用户在因特网上查询信息的工具。它以一定的策略在因特网中搜集、发现信息,对信息进行提取、组织和处理,并为用户提供检索服务,从而起到信息导航的目的。对于搜索引擎来说最关键的问题是在保证找到最全面信息的同时,还要兼顾信息的关联性,因此,选择合适的搜索引擎十分必要。本文对网络环境下的信息检索最常用到的搜索引擎的特点及使用技巧进行了总结.     

INTERNET搜索引擎探解

web搜索是因特网上非常有用的信息检索工具,但是由于目前搜索引擎检索出的信息庞大,且一个特定的搜索引擎主要包含某一特定领域的信息,这使得用户很难获得准确的导航信息,为此本重点介绍了AltaVista和Yahoo等当今流行的两种搜索引擎,并对它们各自的优点和功能进行了分析。通过时它们的分析揭示了目前网上搜索引擎所面临的问题,由此介绍了一种新的web搜索引擎——元搜索引擎,最后介绍了适合于Web信息获取与处理的WIRPL语言以及搜索引擎使用的一些技巧。     

元搜索引擎小议

搜索引擎是我们从网上获取信息资源的有效工具,但是传统的搜索引擎却有着自身的不足,而元搜索引擎是对多个独立搜索引擎的选择和调用,可以比传统的搜索引擎更快更有效的获得信息。本文简介了元搜索引擎的分类及其特点。     

如何利用搜索引擎对科研文献进行便捷的检索

中文搜索引擎的广泛使用带给人们地是大量的信息资源。但过于浩大的信息资源常常干扰检索者的使用效率,导致信息资源对检索者的时间负担。本文从中文搜索引擎的类型和特点出发,介绍了搜索引擎在科研检索中的便捷使用方法。     

搜索引擎的技术发展趋势

作为互联网信息传播的有效载体之一,随着google、百度在纳斯达克神话的上演,越来越多的人开始关注搜索引擎,越来越多的人也开始借助搜索引擎加快对网络信息的浏览。Web上信息量的快速增长,为信息检索工具带来新的挑战与机遇,越来越多的人喜欢基于关键词的自动搜索引擎来完成对信息的快速查询和综合浏览,搜索引擎经过几年的发展和摸索,也越来越贴近人们的需求,成为互联网信息传播的主要方式之一。     

探讨搜索引擎在网络信息挖掘中的应用

本文首先分析了搜索引擎的工作原理,其次简要设计了搜索引擎在网络信息挖掘中应用,并进一步研究了搜索引擎的应用实现,涉及到挖掘预处理、挖掘训练以及信息文件的操作。本文对搜索引擎的应用研究起到一定的借鉴作用。     

垂直搜索引擎技术进展

随着网络与通信技术的迅速发展,为了满足人满对特定领域信息的个性化需求,更具有针对性的垂直搜索引擎应运而生。本文介绍了垂直搜索引擎,并对垂直搜索引擎的核心技术垂直网络蜘蛛技术和信息抽取技术作了介绍,最后进行了总结和展望。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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