基于改进军用安全模型的sJava语言

为了发现、控制软件中的非法信息流,利用改进后的军用安全模型对Java语言的安全性进行扩展,提出了一种基于类型的信息流控制方法.将安全级别编码为程序中的类型,并利用定型规则发现非法的信息流,扩展后的语言称为sJava.给出了sJava类型安全性的证明,实现了对开源的Java编译器Jikes的安全性改造.结果表明,sJava语言源程序能直接编译成字节码,不增加系统的运行负载.     

基于容忍入侵的C代码安全编译技术

提出一种新的基于容忍入侵的C代码安全编译技术.建立信息流的格模型,在保证内存安全的前提下触发信息流安全机制.通过安全类型系统进行信息流的静态分析来检测程序中信息流的安全漏洞,进而保证C代码的信息流安全.     

基于无干扰理论的安全保障方法

近年来,安全保障作为操作系统安全的一个重要方面越来越受到研究者的重视。对于高安全级别操作系统,体系结构层次的结构化是必须要达到的安全保障要求,是其区别于低安全级别系统的本质特征。本文首先分析了传统信息流模型在解决安全保障问题方面的不足,然后以传统无干扰模型为基础,研究了安全保障在其中的描述和体现,提出了能够满足引用监视器假设的结构化规则。其次,提出可信管道的概念,将其应用到无干扰模型的结构化保障中,并对模型的安全性进行了证明。最后,给出了一种基于可信管道的结构化信息流控制的实现方案。     

基于FPGA的模糊温度控制系统设计

介绍了一种二维的热疗温度控制模糊系统,详细介绍了该系统的模糊控制算法及模糊控制规则的建立及其在FPGA上的实现方法.模糊控制比传统控制更能有效地提高恒温控制精度,满足治疗的临床要求.     

一种基于信息流的完整性保护模型

针对可信计算需要保护运行时完整性度量的问题,提出一种基于主体完整性标识动态调整的完整性保护模型.基于Biba模型的严格完整性策略中主体访问的历史过程和客体的完整性标识,通过安全规则对主体的访问范围进行动态调节,以提高模型的可用性.最后,通过无干扰理论对模型的安全性进行了证明,从信息流的发送者和接收者之间的干扰关系上,验证了完整性保护模型的正确性.     

PKI系统中CA服务器的设计与实现

认证机构CA是PK I的核心执行机构,是PK I的主要组成部分,本文简要介绍了PK I的基本组成和CA的架构设计,详细介绍了用Java和O penSSL构建一个小型PK I系统的方法.该PK I系统扩展后可满足一定的安全需求,可用于校园网安全和企业安全应用,能实现CA认证中心的功能,保证网上数据传输的机密性、完整性和不可否认性.     

基于Java规则引擎的Acegi域对象安全扩展

企业应用程序都需要一套完善、灵活、高效的安全措施来保证其完整性和安全性.Acegi安全框架正被越来越广泛地应用于基于Java EE平台的企业应用系统中.本文分析了Acegi在域对象实例访问控制方面支持企业复杂的访问控制之不足,提出应用Java规则引擎来实现控制访问的业务逻辑,给出了使用基于规则引擎的开源产品JBoss Rules来扩展Acegi域对象安全的一种实现方案.实验表明该方案能提高对域对象实例的访问控制,降低业务逻辑与Acegi安全框架的耦合,且易于实施,保证系统运行的性能,有推广应用的前景.     

用于虚拟化环境的进程隔离方法研究与实现

针对虚拟化环境中用户进程运行安全问题,提出一种适用于虚拟化环境的进程隔离方法.该方法引入安全域作为进程隔离保护的基本单元,安全域是进程以及进程运行过程中依赖的环境构成的整体,通过建立安全域之间的依赖关系和安全域之间信息的交换规则,确保进程初始安全和运行过程中的隔离性.给出了安全域的相关概念和形式化描述,以及安全域之间信息流交换和依赖关系的建立方法和相关证明.以Xen虚拟化系统为基础,给出了该保护方法的具体实现以及实验结果,实验结果分析表明:该方法在虚拟化环境中能够抵御多种攻击手段,额外执行开销不超过10%.     

继电保护定值远程安全配置系统的设计与研究

现有继电保护定值管理系统定值单需要经过各级部门校核、审核和审批,再下发到现场进行现场手工整定和配置,大大增加了工作量及系统复杂度,其时效性、可靠性要求也无法得到满足.文中提出一个继电保护定值远程安全配置系统的设计与实现方案.该系统由远程控制中心可信安全模块和定值远程可信控制模块构成,利用嵌入式技术和可信计算技术,实现双方的身份鉴别和密钥交换,完成定值数据传输的机密性和完整性保护.在不改变现有变电站设备的前提下,实现在线校核、审核和审批.调度端在得出保护定值等参数后可直接进行在线远程修改,以此缩短定值管理环节,提高系统的可靠性与稳定性.     

面向虚拟装配的计算机辅助装配工艺规划系统体系结构研究

为了解决虚拟装配工艺规划系统实际应用中的问题,提出了面向虚拟装配的计算机辅助装配工艺规划系统(CAAPPSFVA)体系结构,通过功能模型和信息流模型分析了该体系结构.该系统为虚拟装配系统提供了辅助功能,但与虚拟装配系统之间存在着松散耦合关系,可以独立使用并可与PDM系统实现集成.提出了使用工艺设计树对当前产品结构及其相关工艺文件进行管理的方法.原型系统的实现表明,该体系结构具有开放性、实用性,能够满足虚拟装配系统的需求.     

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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.     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.