VPGE:一个LALR(1)分析器的可视化生成和断点调试系统

LALR(1)分析程序生成系统在编译器构造领域以外被许多普通软件开发者学习和使用.为帮助用户理解LALR(1)分析器方法,编写出正确、完整、无语法分析冲突的文法规范,严格定义了使用LALR(1)分析器生成器时用户可能遇到的几类文法问题,描述一个为帮助用户解决这些问题而开发的LALR(1)分析器可视化和断点调试系统VPGE.VPGE以多种视图显示LALR(1)分析器的数据结构,包括状态栈、符号栈、输入符号串、分析树和底层的自动机,支持LR分析动作的单步执行和断点调试.性能实验结果表明,VPGE比GNU的Bison有更快的分析器生成速度,从而提供了一个LALR(1)文法及分析器的快速交互式调试环境.     

LALR(1)语法分析器的自动生成

文章简单介绍了语法分析器自动生成的原理和技术,根据语法分析器的生成过程,介绍了实用的语法分析器的自动生成器各个部件及其实现的详细过程。     

基于 YACC的UML模型转换器

从实际应用出发,研究UML模型转换器的设计与实现.本文分析了UML建模工具Rose所产生模型的文档结构,构造出其LALR(1)文法,利用YACC工具将其转换为统一的UML模型文档.     

ATLAS-C语法分析器中冲突消解问题的研究

论文对在设计ATLAS-C语法分析器中YACC工具所无法解决的冲突进行了具体的讨论与研究,并且对出现的冲突提出了相应的解决方案。实验结果证明论文提出的消解冲突的方法在设计语法分析器时具有可行性。     

高性能的XML解析器OnceXMLParser

XML(extensible markup language)解析器是分析、处理XML文档的基础软件.研究高性能验证型XML解析器的实现.开发了支持3种解析模型的XML解析器OnceXMLParser,该解析器通过了严格的XML兼容性测试和API兼容性测试.OnceXMLParser具有轻量级体系结构并进行了多方面的性能优化,包括高效的词法分析、基于统计分析的自动机实现、合理的资源分配策略以及语言层次上的优化.性能测试结果表明,OnceXMLParser具有出色的解析性能.     

一种为二义性文法构造SLR(1)分析器的方法

文法具有二义性是实际中经常遇到的情况。本文以SLR（1）分析器为例介绍了一种为二义性文法构造语法分析器的方法,并通过实例分析了利用该方法进行语法分析的过程。     

基于容器(CUP)算法的斑图生成和分析

斑图生成是一个具有生物学背景的复杂系统问题,相比传统的动力学等方法,采用CUP算法进行斑图的生成和分析。同时CUP算法具有容易并行、解释方式多样(概率,结构化)、具有多尺度求解和解释能力、参数多样化和结构多样化等优点,其斑图应用对复杂系统的研究分析有实际的指导意义。     

基于1-Wire(R)的PnP设备识别

文章讨论了一种\"即插即用\"(PnP)设备的识别方法.该方法采用1-Wire(R)器件作为存储器存储识别信息,并已在Dallas公司的TINI(R)板得到了实际的应用.     

LL(1)预测分析器的构造

着重分析了编译原理课程中的LL(1)预测分析器的设计算法。对于给定的代码,求出FIRST、FOLLOW和SELECT集,构造相应的LL(1)预测分析器,给出预测分析表,并对求解FIRST集和FOLLOW集中存在的环问题提出了解决算法。     

GM(1,1)和新陈代谢模型的比较

灰色模型具有所需数据少、预测精度高和无需先验信息的特点。本文通过建立GM(1,1)模型和新陈代谢模型实例预测某省火灾事故发生量,并将两种方法相比较,为相关部门提供科学的决策依据。结果表明灰色模型简单实用,预测精度高。而在此实例中,GM(1,1)模型比新陈代谢的预测精度更高、预测误差更小。     

Parallel construction of SLR (1) and LALR (1) parsers

The generation of an LR parser consists of constructing a parse table, with one row per state (in a push-down automaton), and one column per terminal symbol. Traditionally, this is carried out row by row, with the computation of one row depending (potentially) on all the others. We present a technique for carrying out the lookahead computation of SLR (1) and LALR (1) parsers in a completely parallel fashion. Our technique performs the computation by column, rather than by row. We show that the computation is totally independent for each column, making it ideal for parallelization. The speedup factor of the technique is min (N, T), whereN is the number of processors andT is the number of terminal symbols in the user's grammar.     

A scheme for LR(k) parsing with error recovery part II: error recovery

The paper is the second in a series of three papers devoted to a detailed study of LR(k) parsing with error recovery and correction. Error recovery in LR(k) parsing of a context-free grammar is formalized by extending an LR(k) parser of the grammar such that it accepts all strings over the terminal vocabulary. The parse produced by this extension for a terminal string is a right parse if the string is in the language. In the case of a string not in the language the parse produced by the extension contains so-called error productions which represent the error recovery actions performed by the extension. The treatment is based on the formalization of LR(k) parsing presented in the first paper in the series and it covers practically all error recovery methods designed for LR(k) parsing.     

A scheme for lr(k) parsing with error recovery part iii: error correction

The paper is the third in a series of three papers devoted to a detailed study of LR(k) parsing with error recovery and correction. A new class of syntax errors is introduced, called (k)-local parser defined errors, which suit better than the conventional minimum distance errors for characterization of error detection and recovery in LR(k) parsing. The question whether a given string has n k-local parser defined errors for some integer n is shown to be decidable. Using the formalization of LR(k) parsing and error recovery presented in the first and the second paper in the series it is shown that the canonical LR(k) parser of an LR(k) grammar always has an error recovering extension which is able to produce a correction for any terminal string containing only (k)-local parser defined errors.     

QoS研究的理论框架以及研究现状(1)

文章从分布式多媒体应用端到端QoS控制的角度,首先介绍了QoS的定义和标准,而后分阶段、分层次地阐述了QoS的控制和管理框架,包括QoS控制机制的设计原则、QoS的描述、QoS控制和管理机制以及QoS的控制层次。     

基于灰色GM(1,N)的模糊多元线性回归分析及应用

建立了基于对称三角模糊数的多元线性回归分析模型(简记为F L R模型),利用线性规划求出中心值和模糊度。以我国1995年到2008年粮食产量(来自《中国统计年鉴2009》)为原始数据,进行了多因素模糊拟合分析。利用GM(1,N)模型对2009年至2013年影响我国粮食产量的5个因素指标值进行了预测,将预测值代入FLR模型求出年度粮食产量,并与2009和2010年的实际产量比较,表明这种GM(1,N)模型和FLR模型有机结合形成的复合模型,预测精度高,可操作性强,且具有很高的可信度。     

Information technology (IT) in Saudi Arabia: Culture and the acceptance and use of IT

The unified theory of acceptance and use of technology (UTAUT), a model of the user acceptance of IT, synthesizes elements from several prevailing user acceptance models. It has been credited with explaining a larger proportion of the variance of ‘intention to use’ and ‘usage behavior’ than do preceding models. However, it has not been validated in non-Western cultures. Using a survey sample collected from 722 knowledge workers using desktop computer applications on a voluntary basis in Saudi Arabia, we examined the relative power of a modified version of UTAUT in determining ‘intention to use’ and ‘usage behavior’. We found that the model explained 39.1% of intention to use variance, and 42.1% of usage variance. In addition, drawing on the theory of cultural dimensions, we hypothesized and tested the similarities and differences between the North American and Saudi validations of UTAUT in terms of cultural differences that affected the organizational acceptance of IT in the two societies.