Renaming Detection

Finding changed identifiers is important for understanding the difference between two versions of a program and for detecting and resolving conflicts while merging variants of a program together. Standard practice for differencing and merging relies on line based techniques that do not recognize renamed identifiers. The design and implementation of a tool to automatically detect renamed identifiers between two versions of a program is presented. The system uses an abstract representation of language constructs to enable language awareness without introducing language dependence. Modules for Java and Scheme have been written. The detector works with multiple file pairs, taking into account renamings that span several files. A case study is presented that demonstrates proof of concept. The detector is part of a suite of intelligent differencing and merging programs that exploit the static semantics of programming languages.     

Signed Systems for Paraconsistent Reasoning

We present a novel approach to paraconsistent reasoning, that is, to reasoning from inconsistent information. The basic idea is the following. We transform an inconsistent theory into a consistent one by renaming all literals occurring in the theory. Then, we restore some of the original contents of the theory by introducing progressively formal equivalences linking the original literals to their renamings. This is done as long as consistency is preserved. The restoration of the original contents of the theory is done by appeal to default logic. The overall approach provides us with a family of paraconsistent consequence relations.Our approach is semantical because it works at the level of the propositions; it deals with the semantical link between a proposition and its negation. The approach is therefore independent of the combination of the connectives that are actually applied to the propositions in order to form entire formulas.     

Reasoning with infinite stable models

This paper illustrates extensively the theoretical properties, the implementation issues, and the programming style underlying finitary programs. They are a class of normal logic programs whose consequences under the stable model semantics can be effectively computed, despite the fact that finitary programs admit function symbols (hence infinite domains) and recursion. From a theoretical point of view, finitary programs are interesting because they enjoy properties that are extremely unusual for a nonmonotonic formalism, such as compactness. From the application point of view, the theory of finitary programs shows how the existing technology for answer set programming can be extended from problem solving below the second level of the polynomial hierarchy to all semidecidable problems. Moreover, finitary programs allow a more natural encoding of recursive data structures and may increase the performance of credulous reasoners.     

可拓语义下汉代铜镜纹样的创新设计研究

目的 挖掘汉代铜镜纹样文化性内涵及中国传统纹样再设计价值,并将之创新应用于现代产品包装设计中。方法 首先,分析汉代铜镜纹样的社会属性和艺术属性,运用可拓语义分析的设计方法,提取纹样意向词汇并建构可拓表征模型,获得铜镜纹样文化语义设计区间;其次,辅助图解思维,将词汇语义转换为图解语义,进行语义表达分析和量值获取;最后,形状文法代入图解获得新纹样,与铜镜单元纹样结合生成有辨识度和设计价值的新纹样因子,并展开新纹样因子在产品包装上的设计实践。结论 可拓学相关理论可以将隐性知识转化为可显性表示和理性评价的文化基元,该方法为汉代铜镜纹样文化性内涵的内挖与外显提供可行路径,为中国传统纹样在现代产品包装设计领域中的再现提供一种延续性方法。     

双积分A/D转换器的量程自动转换

介绍了一种双积分式A/D转换器在宽范围量程测量中的自动量程转换技术.在测量仪表的输入通道中,用计数器对双积分型A/D转换器本身所固有的过量程/欠量程信号计数,计数器的输出作为量程编码去控制量程的选择,同时又是送到CPU的量程指示信号.该技术扩大了A/D转换量程,提高了精度,设计简单,工作可靠.     

基于多层次语义特征的建筑立面点云提取方法

建筑立面信息是指建筑物与外部空间接触面的空间分布及属性信息,如何从点云数据中提取建筑立面信息是点云数据处理中的热点和难点.为解决传统格网密度算法在建筑立面点云提取时评价标准单一、适应性不强的问题,综合分析建筑区各类典型地物点云的高程分布、投影密度、法向量分布等局部及整体空间特征,构建由点云单点语义、格网语义及区域语义组...     

广义AND/OR图的自底向上的启发式搜索算法BFA0

本文首先根据三角模及其扩张运算概念,定义了一类新的更具普遍意义的模糊广义AND/OR图。根据新定义的启发式函数h(n,x)以及模糊广义AND/OR图的最佳解树之所有子树亦是最佳子解树的原理,提出了自底向上的启发式搜索算法BFAO·。文中证明了算法BFAO·的可采纳性。本文还提出了两类新的启发式函数的单调限制概念,并据此研究了算法BFAO·的单调限制性质,研究了两个BFAO·算法间的比较性质。     

一种网络学习资源的检索模型研究

首先介绍了四种网络学习模式,并探讨了这四种模式中的最流行的网络学习模式-个别化的网络学习模式的资源特征.然后对个别化的网络学习模式,构建了一种基于语义的检索模型,并对模型中各组成部分的主要作用和模型的检索过程进行了阐述.最后通过实验的验证,证明了模型的合理性和有效性.     

基于位置语义和查询概率的假位置选择算法

针对传统位置隐私保护方案中未充分考虑攻击者拥有背景知识而导致的隐私泄露问题,基于位置语义和查询概率提出一种假位置选择算法。在假位置集中的位置之间满足语义差异性、查询概率相近且地理位置尽量分散的条件下,避免了攻击者结合背景知识过滤假位置,同时保证了查询结果的精确性。仿真实验验证了所提算法能有效保护用户的位置隐私。     

硬件描述语言VHDL指称语义的研究

VHDL是一种广泛使用的硬件描述语言，但长期以来缺乏严格的形式语义，文章介绍并分析了若干具有代表性的VHDL指称语义的研究工具，在此基础上，简要介绍了作者提出的基于时段逻辑的VHDL语义的框架时对VHDL指称语义的看法。