面向RISC-V的汇编程序语义等价性自动化测试系统

本文设计并实现了一套面向RISC-V的汇编程序语义等价性自动化测试系统.在面向RISC-V开发软件时,尤其是基于扩展指令(例如向量指令)编写高效的程序时,很难避免以手写汇编的方式编写代码.例如,为标准的C函数库编写相应的向量版函数.与编译器自动生成的代码不同,手写的汇编代码虽然可以最大限度地提高程序的效率,但因绕过了编译时对程序的约束(如类型检查、寄存器分配等)而对开发者提出了更高的要求.能否对新版本与标准版本的汇编程序进行快速地、自动化的语义等价性测试,将大大影响代码的正确性和软件开发和调试的效率.已有面向RISC-V的测试框架缺乏对语义等价性测试的支持,也未考虑程序执行带来的副作用.本研究基于模拟器的动态测试环境,设计并实现了一套面向RISC-V的汇编程序语义等价性自动化测试系统.系统通过跟踪机器状态,捕获程序执行的副作用,并结合用户定义的测试目标生成测试报告.实验表明,本系统相比已有的测试系统,能够有效地对RISC-V汇编程序的语义等价性进行测试.     

TMS与一般逻辑程序的语义等价性

1.稳固模型和良构指派 首先假定读者已熟悉有关逻辑程序设计的最基本概念,有关详细论述请参阅[3]。 定义1.设P是一Horn逻辑程序(简称Horn程序),B_P是P的Herbrand域.T_P是一从解释I到另一解释T_P(I)的映射,定义为: T_P(I)={A∈B_P|存在P中某子句的实例代换A←A_1,…,A_n,使得{A_1,…,A_n}I}     

多出口petri网与petri网的等价性

1.引言 为了便于描述程序的控制结构,文[1,2]引入了多出口Petri网的概念,并指出,在一定意义下,多出口Petri网与一般Petri网是等价的。本文旨在从理论上讨论这两个概念的等价性,并给出严格的证明。     

项重写系统等价性的归纳证明

尽管学者们在计算机软件理论及相关数学理论方面做出了不懈的努力,但伴随着计算机硬件的高速发展而来的软件危机却日益严峻,其原因复杂多样。其中,主要原因之一是缺乏程序验证的方法和工具。程序设计的主要步骤有:描述问题、设计程序、实现程序及测试程序。需要注意的是,这里是测试程序的正确性而非证明程序的正确性,这样程序的正确性就不能从根     

基于驱动的进程创建监控的实现

介绍了驱动开发技术背景及应用,讲述SSDTHOOK方法,实现监控NtCreateProcessEx系统服务。RING3应用程序和驱动程序的交互,RING3应用程序和驱动程序的同步实现基于驱动的进程创建监控。     

DOOL程序语义等价转换为Datalog 程序的转换规则

演绎对象数据库(DOOD)是演绎数据库与面向对象数据库两者优点相结合的产物。笔者设计实现了一个演绎对象数据库系统原型SD-DOOD,它是基于演绎数据库系统SD-DDBS的。然而,它使用的是演绎对象库语言DOOL,而演绎数据库语言是基于Datalog的,因此该文提出了应用一些转换规则来将DOOL程序转换为Datalog,通过规则转换,能求出DOOL程序的最小不动点(即程序值),从而使得系统的查询操作全都由SD-DDBS最终得出结果。文中详细介绍了转换规则的具体内容。     

丰富特征提取的句子语义等价识别研究

句子语义等价识别任务(SSEI)在问答任务中扮演着至关重要的角色.目前,基于中文的语义等价任务在没有给定场景的前提下直接判断两个问句的语义,仍存在相同的意思也会被错误理解的问题.因此,本文提出了一种丰富特征信息提取的RFEM(richer feature extraction model)模型.首先,在编码层中,使用C...     

表的等价性的NP完全性的讨论

本文给出了表的等价性判定的一些结果：三元可满足性问题，表达式的ＮＰ完全性，表的ＮＰ完全性，还给出了函数依赖对表的影响，强等价性的复杂性的一些讨论。为对表的进一步研究屯指出了方向。     

基于进程代数的构件语义标注技术研究

针对组合构件的语义标注问题,提出基于进程代数的自动标注方法,以减小构件库开发人员手工标注大粒度组合构件语义的工作量。采用本体描述构件的语义,对于不同结构的组合行为,通过进程演算抽取交互行为的执行序列,给出组合构件语义的抽取、合成方法及相应的语义标注算法。将该技术集成到JTangComponent平台上进行实验,结果标明其提高了语义标注的自动化程度,可以为复用构件提供语义保障。     

An Input/Output Semantics for Distributed Program Equivalence Reasoning

A new notion of input/output equivalence of distributed imperative programs, with synchronous communications, is introduced. It preserves the input/output relation, encompassing both, initial/final state and communication channel values. For its mathematical justification, the semantic framework of Manna and Pnueli, based on finite transition systems and reduced behaviors, is extended with the notion of input/output behavior. A set of laws for the equivalence is overviewed. A deduction rule for the substitution of references to input/output equivalent procedures is defined and justified in the new semantics. The rule is applied to decompose distributed program simplification proofs, introduced in a prior work, which use the laws to establish the equivalence between a sequential and a parallel communicating program. They include communication elimination as one of their steps. An outline of one of such proofs, for a pipelined processor model, is included.     

Strong Negation and Equivalence in the Safe Belief Semantics

The safe belief semantics uses intermediate logics to definean extension of answer sets to all propositional formulas, butonly considering one kind of negation. In this work we extendsafe beliefs adding the strong negation connective. The mainfeature of our extension is that strong negation can occur beforeany formula, and not only at the atomic level. We give resultsconcerning the relation between strong negation extensions ofintermediate logics and safe beliefs and consider the way inwhich strong negation can be eliminated from any formula whilepreserving its semantics. We also propose two new notions ofequivalence: substitution equivalence and contextualized equivalence.We prove that they are both more general than strong equivalenceand, for propositional formulas where strong negation may occurat the non-atomic level, substitution equivalence captures anotion of equivalence that cannot be captured by strong equivalencealone.     

分布式数据库查询优化处理——基于关系代数等价变换的查询优化处理

在进行分布式数据库应用时，快速而准确的得到查询结果一直是分布式数据库得以应用的关键问题。本文阐述了分布式查询优化的一种策略和算法——基于关系代数等价变换的查询优化处理。     

基于层次分析法的停电试验与不停电检测技术等效性分析模型

为了评价停电试验与不停电检测技术的等效性,提出了一种基于层次分析法的停电试验与不停电检测技术等效性分析模型。首先根据两种技术的状态量获取过程确定了准确度、有效性与故障检出能力组成的准则层,以及数据数值准确度等七个指标构成的指标层。采用层次分析法计算各指标权重系数,建立了双层次的等效性评价指标体系。根据各指标层中各指标性质,确定各个指标层指标的量化方法及归一化计算方法。针对不停电检测和停电试验的数据数量不相等、时序不匹配的特点,提出了数据三次样条插值拟合后再取值的数据预处理方法,最终建立等效性分析模型。实例分析表明该模型可以减少人为干预,综合状态量数据获取的主要阶段来评价不停电检测对停电试验的等效性。     

Distributed On-the-Fly Equivalence Checking

On-the-fly equivalence checking consists in comparing two Labeled Transition Systems (Ltss) modulo a given equivalence relation by exploring them in a demand-driven way. Since it avoids the explicit construction of Ltss, this method is able to detect errors even in systems that are too large to fit in the memory of a computer. In this paper, we aim at further improving the performance of on-the-fly equivalence checking using several machines connected by a network. We propose DSolve, a new algorithm for distributed on-the-fly resolution of Boolean Equation Systems (Bess), which enables equivalence checking modulo various relations characterized in terms of Bess. DSolve serves as verification engine for the distributed version of Bisimulator, an on-the-fly equivalence checker developed within the Cadp verification toolbox using the Open/Cæsar environment. Our experimental measures show quasi-linear speedups and a good scalability of the distributed version of Bisimulator w.r.t. its sequential version.     

基于等价关系的关联规则挖掘算法研究

文章在现有关联规则挖掘算法的基础上,基于等价关系和等价类来生成侯选频繁项目集,它可以减少系统的开销;并利用参照数据集代替原始交易数据库进行侯选频繁项目集中支持度计数的测试,以此来减少对原始交易数据库的扫描次数。这种方法对于挖掘关联规则是有效的。     

Bridging Real World Semantics to Model World Semantics for Taxonomy Based Knowledge Representation System

As a mean to map ontology concepts, a similarity technique is employed. Especially a context dependent concept mapping is tackled, which needs contextual information from knowledge taxonomy. Context-based semantic similarity differs from the real world similarity in that it requires contextual information to calculate similarity. The notion of semantic coupling is introduced to derive similarity for a taxonomy-based system. The semantic coupling shows the degree of semantic cohesiveness for a group of concepts toward a given context. In order to calculate the semantic coupling effectively, the edge counting method is revisited for measuring basic semantic similarity by considering the weighting attributes from where they affect an edge's strength. The attributes of scaling depth effect, semantic relation type, and virtual connection for the edge counting are considered. Furthermore, how the proposed edge counting method could be well adapted for calculating context-based similarity is showed. Thorough experimental results are provided for both edge counting and context-based similarity. The results of proposed edge counting were encouraging compared with other combined approaches, and the context-based similarity also showed understandable results. The novel contributions of this paper come from two aspects. First, the similarity is increased to the viable level for edge counting. Second, a mechanism is provided to derive a context-based similarity in taxonomy-based system, which has emerged as a hot issue in the literature such as Semantic Web, MDR, and other ontology-mapping environments.     

基于语义分解的人机任务快速规划及仿真自动生成方法

人机任务仿真规划是人机系统应用的基础性工作,也是任务仿真制作过程中最具专 业性和复杂性的工作之一,研究人机任务仿真快速规划方法对提高人机系统的应用水平具有重要 的意义。针对现有人机系统中人机任务仿真交互量大、仿真进程不能自动生成以及仿真结果重用 性差等问题,提出一种基于语义分解的人机任务快速规划及仿真自动生成方法。首先,采用分层 模式,对人机任务的自然语义进行逐层分解和细化,直至最终可由计算机系统直接实现和执行的 动作来描述为止;然后,引入任务路径、轨迹和进程等概念,对复杂人机任务过程进行结构化定 义和表示,提出相应的图形化人机任务过程图形化规划方法,并在此基础上建立人机任务仿真自 动生成方法。开发支持这种方法的程序原型,并以飞机装配中卡板打开操作为例,对这种方法进 行测试和验证。