基于动态分析的控制流劫持攻击检测

控制流完整性策略能够有效地防御控制流劫持类攻击,但复杂的控制流图构建使该策略的实际部署非常困难.为了有效地针对控制流劫持攻击的检测手段,提出一种基于程序异常行为来检测控制流劫持攻击的方法,并基于该方法实现了控制流劫持攻击检测系统.实验表明,该方法能够有效地检测出由控制流劫持攻击造成的各种程序异常行为,基于该方法的攻击检测系统运行效果良好,能够方便的部署到实际应用环境中.     

基于语义抽象的内存访问错误检测

为了检测内存访问错误,提出了一种基于语义抽象的内存访问错误检测方法,通过对程序具体语义的完备近似抽象,对相关约束变量操作的精确检验,以及控制流图遍历中的函数信息收集,能够在过程间完备地静态检测C程序源代码中的内存访问边界错误.通过将程序分析和程序验证相结合,提高内存检查的自动化和准确性.原型实现表明了方法的有效性.     

一个程序静态分析方法

阐述了程序静态分析方法，指出如何建立程序调用关系结构树、程序控制流和数据流，以及如何找出程序的结构错误、异常控制流和数据流．     

面向并发程序的重构一致性检测方法

针对并发软件重构后可能带来的行为不一致问题,提出了一种重构一致性检测方法,该方法使用控制流分析和数据流分析检测重构前后的变化,使用同步依赖分析检测重构前后同步依赖关系的变化.针对对象重用性、静态共享字段、死锁3种典型的引起并发错误的情况,设计了3种检测算法对重构前后程序的不一致性进行检测.依据该方法,在WALA软件分析框架下实现了一个原型检测工具.在实验中,使用该工具在SPECjbb2005和HSQLDB测试程序上进行了验证,并与Schafer等提出的方法进行比较,实验结果表明,该方法能够有效地发现并发软件重构的不一致行为.     

一种针对可执行代码的内存泄漏静态分析方案

针对应用程序安全分析的实际需求,设计并实现了一个针对可执行代码的内存泄漏分析框架MLAB.MLAB首先从可执行代码中恢复控制流和数据流信息,依据恢复的控制流图建立程序的有限状态自动机,在此基础上运用模型检测算法分析程序可能存在的内存泄漏.利用几个典型的程序实例详细说明了MLAB方法的工作原理,并通过基于测试程序集MiBench的实验对方法进行了验证,结果说明了该方法的有效性.     

一种基于人工神经网络的基本块重排方法

基于程序的控制流动信息和体系结构跳转代价模型,使用人工神经网络预测控制流边的执行概率,利用子结构分析技术开展基本块重排.程序的控制流边信息被选择作为神经网络的训练数据,这些信息包含了该边的静态特征和动态行为之间的联系.基于弹性反馈反向传播(RPROP)神经网络,在UniCore处理器上实现了采用子结构分析的基本块重排算...     

WS-CDL测试路径的生成与排序

为了找出WS-CDL组合流程中存在的错误,减少软件维护产生的开销,提出一种基于控制流图生成测试路径的方法,用于对WS-CDL进行测试.首先解析WS-CDL文档,根据元素特点生成各类节点,并根据流程结构确定节点的源节点和目标节点;然后通过在源节点和目标节点间添加有向边构造成控制流囹;最后通过遍历控制流图生成所有可能的测试路径.测试路径中覆盖的WS-CDL元素越多,则发现的错误数也可能越多.为提高发现错误的效率,提出了2种基于路径中元素数量的排序算法,对路径的执行顺序进行排序.实验结果表明,将测试路径按路径中未被覆盖的元素总数降序排列,可以更快地发现错误.     

一种面向分布式系统的行为分析和检测方法

提出了一种基于进程代数的行为分析与检测方法.通过静态分析二进制码获得系统的控制流程图,并将其转换为进程表达式;通过消除表达式不确定性、添加并发操作以及约简归并等方式对表达式进行重写;根据并发规则消除进程表达式中的并发算子,建立分布式系统的行为检测模型,并给出行为检测的方法.理论分析和实验表明:所提出的方法降低了行为分析和检测的复杂度,在控制流分析方面具有较好的精确性.     

基于改进GN算法的程序控制流图划分方法

针对控制流图规模过大导致的程序分析准确度和效率不够理想的问题,该文提出了一种用于控制流图划分的改进GN(Girvan-Newman)算法,在边介数计算中加入点权值作为参数,使划分所得各子图的规模更加平衡;通过动态控制子图的规模,在合适的时机提前终止算法执行,提高执行效率。利用angr工具对二进制程序进行分析所得到的控制流图,分别采用改进GN算法、K-means算法、谱聚类算法和朴素凝聚算法进行实验,比较不同算法对控制流图划分结果中的模块度以及均衡性等指标,证明改进GN算法具有最佳的划分结果和执行效率。     

采用控制流监控的Cisco IOS指针攻击检测方法

针对当前Cisco IOS(internetwork operating system)漏洞攻击检测方法检测效率低的问题,提出了一种采用控制流监控来判定Cisco IOS指针攻击的方法。该方法通过静态分析和动态跟踪相结合的方式对Cisco IOS中不同类别的控制流分别构造合法转移地址集合(legal transfer address collection,LTAC),并在发生控制流转移时将转移地址在LTAC之外的控制流判定为攻击,同时捕获异常控制流转移的详细信息。实验结果表明:该方法可以准确地捕获针对Cisco IOS的指针攻击,支持对攻击过程的分析,与现有的Cisco IOS漏洞攻击检测方法相比,具有较高的检测效率,能够为网络安全性的提升提供帮助。     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has