基于上下文的Android移动终端可信运行控制系统的设计与实现

Android手机、平板电脑等智能移动终端的快速普及,使得对Android系统安全性能的需求也在不断提高.当前比较普遍的做法是在终端上安装监控软件来检测病毒和恶意软件等,但这种方式并不能保证监控软件不被旁路、欺骗和篡改.针对这个问题,本文设计并实现了基于上下文的Android移动终端可信运行控制系统,通过对Android OS安全启动信任链的构建,保证了系统的安全,同时支持基于地理位置的Android应用程序的完整性远程验证.     

Android应用安全审核认证系统的设计研究

由于APK应用具有开放性,使其很容易在反编译和重新打包过程中植入第三方代码,由此为Android系统带来了严重的安全问题。为解决APK应用内容恶意篡改问题,对APK建立安全可信的发布和运行环境,在服务端和客户端分别建立安全审核和安全认证模块。系统实现了对APK应用的签名和验证功能,为解决APK应用的内容安全问题提供了解决方案。     

HTML5少数民族文献数字化平台Android App 开发研究

HTML5与Android系统第三方应用程序开发技术的兴起推动了跨平台Web应用快速发展, 少数民族文献数字化平台使用三方软件APP应用程序实现系统的跨平台访问成为一项值得深入研究的课题. 概述了HTML5架构下的少数民族文献数字化平台与Android APP的无缝对接技术, 详细阐述少数民族文献数字化平台的服务器端架构和UI界面设计. 最后, 详细介绍了客户端的基于Android的少数民族文献数字化平台第三方应用软件开发.     

HTML5少数民族文献数字化平台Android App开发研究

HTML5与Android系统第三方应用程序开发技术的兴起推动了跨平台Web应用快速发展,少数民族文献数字化平台使用三方软件APP应用程序实现系统的跨平台访问成为一项值得深入研究的课题.概述了HTML5架构下的少数民族文献数字化平台与Android APP的无缝对接技术,详细阐述少数民族文献数字化平台的服务器端架构和UI界面设计.最后,详细介绍了客户端的基于Android的少数民族文献数字化平台第三方应用软件开发.     

Android恶意广告威胁分析与检测技术

Android第三方广告框架应用广泛,但Android系统漏洞和Android第三方广告框架的逻辑缺陷严重威胁着Android市场安全。攻击者可以通过恶意广告获取敏感数据、触发敏感操作,甚至是以应用程序的权限执行任意代码。该文总结了4种Android恶意广告攻击方式,并针对这4种方式设计了一种基于后向切片算法和静态污点分析的Android第三方广告框架静态测量方法,以及一种基于API Hook和靶向API Trace的Android恶意广告敏感行为动态检测方法。基于以上研究,该文设计并实现了Android恶意广告威胁分析与检测系统,通过实例证明该系统能够有效地分析Android第三方广告框架可能存在的安全隐患,并能够动态检测Android恶意广告的敏感行为。     

基于Android应用程序的第三方类库检测系统

随着Android系统的不断升级与其应用领域的扩张,基于Android平台的第三方类库的数量也越来越多,某些类库带有严重的安全漏洞,导致集成该类库的app也有了各种安全隐患.因此,基于Android平台的第三方类库的检测,有着重要意义.本文在前人研究工作的基础上,通过对第三方类库的源码进行合理的特征选取,然后进行哈希运算,将结果作为特征值存储在特征库中,最终通过特征匹配的方法检测出对于给定的Android应用程序都使用了哪些第三方类库.最后通过实验分析得出,该方法能够有效的检测出app中的第三方类库.     

基于可信第三方的防欺骗视觉密码分享方案

传统的视觉密码方案需要参与者相互验证,因此存在着一系列检测过程,不够简洁、应用不够广泛等问题;基于这一点,提出了一种需要引入第三方的防欺骗视觉密码分享方案;该方案采用异或(XOR)运算,利用可信第三方和受怀疑的分享图像能否恢复出验证图像来实现真实性检验,可直接验证分发者和参与者的欺骗行为,具有方便快捷和不受存取结构限制的特点。     

基于系统调用的安卓恶意应用检测方法

针对恶意应用静态检测方法精度低的问题,以安卓(Android)应用运行时产生的系统调用为研究对象,提出1种恶意应用动态检测方法。将Android移动应用在沙盒环境下通过事件仿真获得的系统调用序列进行特征化,设计了基于系统调用次数和基于系统调用依赖图的2种特征表示方法。采用集成学习方法构建分类器,区分恶意应用和正常应用。采用来自于第三方应用市场的3 000个样本进行了实验验证。结果表明,基于系统调用依赖图的特征表示方法优于基于系统调用次数的特征表示方法,采用集成分类器具有较好的检测精度,达95.84%。     

一种改进的无需可信任第三方的时控代理签名方案

应用现实生活中"分权"的思想和(t,n)门限群签名技术,提出一种改进的无需可信任第三方的时控代理签名方案.该方案在对签名时间验证服务上,不再由一个可信的第三方来提供,而是由一个群体(t个人)来对代理签名时间和待签名的消息实行二级签名,能够避免(t,n)门限群签名时消息浏览权被扩大化和防止消息被泄密,除了满足代理签名的所有性质外,还能确定代理人签名的准确时间,当代理权被滥用时,授权人还可以将代理权撤销.     

基于SHA-1模块的可信嵌入式系统安全启动方法

在可信嵌入式系统中,嵌入式设备启动过程的安全是运行状态安全的基础,因此提出了一种可信嵌入式系统安全启动方法。针对可信嵌入式系统中的嵌入式设备原有硬件结构不改变的情况,在嵌入式设备上电后进行交互验证,然后再利用SHA-1模块对启动过程中的程序代码进行完整性度量。实验结果表明,设计的SHA-1模块功能可靠,能够应用在可信嵌入式系统中实现完整性度量,从而结合系统上电交互验证过程实现嵌入式设备的安全启动。该方法能够保持现有嵌入式设备的原有硬件结构不变,具有普遍的适应性。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to