椭圆曲线密码中抗功耗分析攻击的标量乘改进方案

椭圆曲线标量乘法运算是椭圆曲线密码(ECC)体制中最主要的计算过程,标量乘法的效率和安全性一直是研究的热点。针对椭圆曲线标量乘运算计算量大且易受功耗分析攻击的问题,提出了一种抗功耗分析攻击的快速滑动窗口算法,在雅可比和仿射混合坐标系下采用有符号滑动窗口算法实现椭圆曲线标量乘计算,并采用随机化密钥方法抵抗功耗分析攻击。与二进制展开法、密钥分解法相比的结果表明,新设计的有符号滑动窗口标量乘算法计算效率、抗攻击性能有明显提高。     

基于欧氏距离及向量内积的骨架提取算法

对骨架算法进行研究,提出一种骨架提取算法.通过对图像内部像素点进行距离变换得到其最近边界点的位置,将内部像素点到最近边界点的向量定义为边界向量,根据物体内部相邻边界向量的方向,计算每个像素点的内积值和其8邻域的最小内积值,得到的最小内积点,以确定的阈值从最小内积点中选取骨架种子点,再对骨架种子点进行处理,得到连通的骨架.试验证明这种算法能保证骨架具的完整性和连通性,正确反映物体的拓扑结构.     

Requirements model driven adaption and evolution of Internetware

Today’s software systems need to support complex business operations and processes.The development of the web-based software systems has been pushing up the limits of traditional software engineering methodologies and technologies as they are required to be used and updated almost real-time,so that users can interact and share the same applications over the internet as needed.These applications have to adapt quickly to the diversified and dynamic changing requirements in the physical,technological,economical and social environments.As a consequence,we are expecting a major paradigm shift in software engineering to reflect such changes in computing environment in order to better address the fundamental needs of organisations in this new era.Existing software technologies,such as model driven development,business process engineering,online(re-)configuration,composition and adaptation of managerial functionalities are being repurposed to reduce the time taken for software development by reusing software codes.The ability to dynamically combine contents from numerous web sites and local resources,and the ability to instantly publish services worldwide have opened up entirely new possibilities for software development.In retrospect to the ten years applied research on Internetware,we have witnessed such a paradigm shift,which brings about many changes to the developmental experience of conventional web applications.Several related technologies,such as cloud computing,service computing,cyber-physical systems and social computing,have converged to address this emerging issue with emphasis on different aspects.In this paper,we first outline the requirements that the Internetware software paradigm should meet to excel at web application adaptation;we then propose a requirement model driven method for adaptive and evolutionary applications;and we report our experiences and case studies of applying it to an enterprise information system.Our goal is to provide high-level guidelines to researchers and practitioners to meet the challenges of building adaptive industrial-strength applications with the spectrum of processes,techniques and facilities provided within the Internetware paradigm.     

由计算机技术与数字艺术专业的关系引发的思考

近年来,广东省把动漫、会展等专业作为新兴行业,在全省技工院校进行免费招生,即省财政给予这些专业相应的财政补贴,学生则可以免交约两年学费。为此,广东省各级技工院校多数都开设了这类专业并进行招生,其中有一些已经拥有这类专业几十年办学经验的院校,也不乏有依靠政策支持儿新开设这类专业的院校。数字艺术是建立在电脑硬件和数字艺术软件基础之上的,所以数字艺术的发展也依附它们,也有很多软件公司走在了前面,随着各国的经济明显好转,产品开发的脚步正在加快,商业美术设计领域将进一步获得巨大发展,相对应的必然是需求大量专业人才,Graphic Design显然是具有灿烂的就业前景。     

Mullitization of high-alumina refractory raw material

Conclusions The stability of the phase composition of sintered material, essential for production processes, is achieved by firing at 1600° for a brief period.Materials made of Novaya Selitsa kaolin, and particularly Arkalyk rock, of which very intensive mullitization is typical, are exceptionally valuable argillaceous components for charges for making high-alumina refractories by the present system of technology (on the basis of charges composed of refractory clays and commercial alumina).     

Method of Noise-Robust Estimation of Parameters of an Autoregressive Model in the Frequency Domain

The article considers the problem of estimating the parameters of the autoregressive (AR) signal in the presence of background noise. Based on the frequency representation of the AR signal, a technique of calculating the likelihood function of the AR parameters is shown and the implementation of the Expectation-Maximization method for iterative evaluation of the AR parameters is considered. Analysis of different measures of distortion of speech signals shows that the proposed approaches in the frequency domain have the same accuracy as the corresponding approaches in the time domain, but are characterized by significantly lower computing costs.

     

Guaranteeing performance for uncertain nonlinear systems with bounded state constraint and mismatching condition

The control design problem for the uncertain nonlinear system with bounded state constraint and mismatching condition is considered in this paper. The uncertainty in the system, which may be due to unknown system parameters and external disturbance, is nonlinear and time‐varying. The state of the system is constrained to be bounded. The system does not satisfy the (global) matching condition. A creative one‐to‐one state transformation is proposed by converting the bounded states into the unbounded ones. A step‐by‐step state transformation is proposed to convert the mismatched system into a matched system. The robust control is then proposed based on the transformed system. The control is demonstrated to be able to guarantee the uniform boundedness and uniform ultimate boundedness of the system in the presence of uncertainty, while the state constraint can be always guaranteed.     

禁飞区无人机预警算法研究

针对大量在空中无秩序飞行的无人机有可能会闯入飞机场等禁飞区的情况,为了避免发生空中交通安全事故,提出了一种无人机禁飞区预警算法。首先,该算法经过坐标变换将描述无人机位置点的GPS坐标转换成对应的平面坐标;接着,采用改进的最小二乘曲线拟合算法预测出无人机的飞行轨迹;然后,通过计算预测的飞行轨迹曲线在当前点的切线是否会与描述禁飞区的电子围栏相交,来判断无人机是否会进入禁飞区。同时,所有的无人机都会安装上飞行数据记录模块,来实时地为该算法提供无人机的飞行状态信息。最后,通过MATLAB仿真实验验证了该预警算法的可行性和有效性,表明该算法可以对禁飞区周围的无人机进行预警。     

Effects of laser heat treatment on the fracture morphologies of X80 pipeline steel welded joints by stress corrosion

The surfaces of X80 pipeline steel welded joints were processed with a CO2 laser, and the effects of laser heat treatment （LHT） on H2S stress corrosion in the National Association of Corrosion Engineers （NACE） solution were analyzed by a slow strain rate test. The fracture morphologies and chemical components of corrosive products before and after LHT were analyzed by scanning electron microscopy and energy-dispersive spectroscopy, respectively, and the mechanism of LHT on stress corrosion cracking was discussed. Results showed that the fracture for welded joints was brittle in its original state, while it was transformed to a ductile fracture after LHT. The tendencies of hydrogen-induced corrosion were reduced, and the stress corrosion sensitivity index decreased from 35.2% to 25.3%, indicating that the stress corrosion resistance of X80 pipeline steel welded joints has been improved by LHT.     

水平切片解释方法在焦作井田构造复杂区的应用

河南焦作某矿地处焦作煤田东部,该矿东三盘区地质构造复杂,主采的2号煤层底板与L_8灰岩平均间距仅20m,与奥灰顶界面平均间距约100m,因此断层的存在极易导通奥灰水,形成较大的水患事故。故查明区内构造分布情况十分必要。本文重点介绍了用三维地震常规解释方法结合偏移及方差数据体水平切片解释方法在构造复杂区的应用情况,具有一定的推广意义。