A Construction of 1-Resilient Boolean Functions with Good Cryptographic Properties

This paper proposes a general method to construct 1-resilient Boolean functions by modifying the Tu-Deng and Tang-Carlet-Tang functions. Cryptographic properties such as algebraic degree, nonlinearity and algebraic immunity are also considered. A sufficient condition of the modified functions with optimal algebraic degree in terms of the Siegenthaler bound is proposed. The authors obtain a lower bound on the nonlinearity of the Tang-Carlet-Tang functions, which is slightly better than the known result. If the authors do not break the “continuity” of the support and zero sets, the functions constructed in this paper have suboptimal algebraic immunity. Finally, four specific classes of 1-resilient Boolean functions constructed from this construction and with the mentioned good cryptographic properties are proposed. Experimental results show that there are many 1-resilient Boolean functions have higher nonlinearities than known 1-resilient functions modified by Tu-Deng and Tang-Carlet-Tang functions.     

A CRYPTOGRAPHIC STUDY ON S—BOXES OF DES TYPE Ⅱ——AN ENTROPY LEAKAGE ANALYSIS FOR THE KEY

The concept of key-entropy drop in an S-box is introduced.It is established that theoutput functions of the permutations composing an S-box belong to three patterns of key-entropydrop.An analysis of the distribution of the key-entropy drop patterns in the 8 S-boxes in the DEShas been made.     

Energy-efficient and security-optimized AES hardware design for ubiquitous computing

Ubiquitous computing must incorporate a certain level of security. For the severely resource constrained applications, the energy-efficient and small size cryptography algorithm implementation is a critical problem. Hardware implementations of the advanced encryption standard （AES） for authentication and encryption are presented. An energy consumption variable is derived to evaluate low-power design strategies for battery-powered devices. It proves that compact AES architectures fail to optimize the AES hardware energy, whereas reducing invalid switching activities and implementing power-optimized sub-modules are the reasonable methods. Implementations of different substitution box （S-Boxes） structures are presented with 0.25μm 1.8 V CMOS （complementary metal oxide semiconductor） standard cell library. The comparisons and trade-offs among area, security, and power are explored. The experimental results show that Galois field composite S-Boxes have smaller size and highest security but consume considerably more power, whereas decoder-switch-encoder S-Boxes have the best power characteristics with disadvantages in terms of size and security. The combination of these two type S-Boxes instead of homogeneous S-Boxes in AES circuit will lead to optimal schemes. The technique of latch-dividing data path is analyzed, and the quantitative simulation results demonstrate that this approach diminishes the glitches effectively at a very low hardware cost.     

Robust On-Line Fault Diagnosis for Nonlinear Difference-Algebraic Systems Using Least Squares Estimate

A new robust on-line fault diagnosis method based on least squares estimate for nonlinear difference-algebraic systems (DAS) with uncertainties is proposed. Based on the known nominal model of the DAS, this method firstly constructs an auxiliary system consisting of a difference equation and an algebraic equation, then, based on the relationship between the state deviation and the faults in the difference equation and the relationship between the algebraic variable deviation and the faults in algebraic equation, it identifies the faults on-line through least squares estimate. This method can not only detect, isolate and identify faults for DAS, but also give the upper bound of the error of fault identification. The simulation results indicate that it can give satisfactory diagnostic results for both abrupt and incipient faults.     

Energy-efficient and security-optimized AES hardware design for ubiquitous computing

Ubiquitous computing must incorporate a certain level of security.For the severely resource con-strained applications,the energy-efficient and small size cryptography algorithm implementation is a critical problem.Hardware implementations of the advanced encryption standard(AES)for authentication and encryption are presented.An energy consumption variable is derived to evaluate low-power design strategies for battery-powered devices.It proves that compact AES architectures fail to optimize the AES hardware energy,whereas reducing invalid switching activities and implementing power-optimized sub-modules are the reasonable methods.Implemen tations of different substitution box(S-Boxes)structures are presented with 0.25 μm 1.8 V CMOS(complementary metal oxide semiconductor)standard cell library.The comparisons and trade-offs among area,security,and power are explored.The experimental results show that Galois field composite S-Boxes have smaller size and higheat security but consume considerably more power,whereas decoder-switch-encoder S-Boxes have the best power characteristics with disadvantages in terms of size and security.The combination of these two type S-Boxes instead of homogeneous S-Boxes in AES circuit will lead to optimal schemes.The technique of latch-dividing data path is analyzed,and the quantitative simulation results demonstrate that this approach diminishes the glitches effectively at a very low hardware cost.     

一种AES算法的FPGA设计与快速实现

针对AES算法特点,提出一种适于FPGA实现的改进的快速AES算法。本方案采用轮内流水线结构和密钥并行处理,ECB操作模式,并且可在一块芯片上同时支持128、192、256bit三种密钥长度,因而在占用相对较少的逻辑资源下提高了系统吞吐率,并且极大的增强了其安全性和使用周期。通过优化的逻辑层次和时序设计,较好地解决了并行处理中的子密钥与轮函数的时序节拍与控制关系,给出了仿真图。实验结果表明该设计相比其他一些设计具有更高性能。     

改进的结构建模方法在煤矿综合管理中的应用

针对解释结构建模中的强连通子集划分、区域划分和级别划分，提出了相应的改进方法，引入了求骨架矩阵的代数表达式，并应用于煤矿经济、技术综合管理之中。在对问题背景的分析介绍的基础上，给出了系统的概念模型，运用所提出的改进方法建立了矿务局经济、技术系统的结构模型。文中演示了具体的计算过程和实施步骤，证实了改进方法的简捷性和有效性.     

基于Simulink的同步发电机仿真代数环问题研究

代数环在Simulink仿真中普遍存在,代数环的存在会降低仿真速度和精度,甚至导致仿真出错。以同步发电机仿真为例,对Simulink仿真中出现的代数环问题及其消除方法进行研究。从同步发电机基本方程分析入手,探讨仿真中引起代数环的原因,指出代数环对系统仿真的影响,重点讨论利用拆解法和变换法消除代数环,并从仿真时间、仿真精度等方面,对消除代数环后系统仿真结果进行对比分析。结果表明:代数环消除后系统仿真速度明显提高;变换法较拆解法,在系统动态仿真精度上有显著优势。     

Non-fragile decentralized H∞ controller design for uncertain linear systems

Considering the design problem of non-fragile decentralized H∞ controller with gain variations, the dynamic feedback controller by measurement feedback for uncertain linear systems is constructed and studied. The parameter uncertainties are considered to be unknown but norm bounded. The design procedures are investigated in terms of positive definite solutions to modify algebraic Riccati inequalities. Using information exchange among local controllers, the designed non-fragile decentralized H∞ controllers guarantee that the uncertain closed-loop linear systems are stable and with H∞ -norm bound on disturbance attenuation. A sufficient condition that there are such non-fragile H∞ controllers is obtained by algebraic Riccati inequalities. The approaches to solve modified algebraic Riccati inequalities are carried out preliminarily. Finally, a numerical example to show the validity of the proposed approach is given.     

Non-fragile decentralized H∞ controller design for uncertain linear systems

Considering the design problem of non-fragile decentralized H∞ controller with gain variations, the dynamic feedback controller by measurement feedback for uncertain linear systems is constructed and studied. The parameter uncertainties are considered to be unknown but norm bounded. The design procedures are investigated in terms of positive definite solutions to modify algebraic Riccati inequalities. Using information exchange among local controllers, the designed non-fragile decentralized H∞ controllers guarantee that the uncertain closed-loop linear systems are stable and with H∞ -norm bound on disturbance attenuation. A sufficient condition that there are such non-fragile H∞ controllers is obtained by algebraic Riccati inequalities. The approaches to solve modified algebraic Riccati inequalities are carried out preliminarily. Finally, a numerical example to show the validity of the proposed approach is given.     

Characteristic polynomial assignment in F-M model Ⅱ of 2-D systems

The problems of characteristic polynomial assignment in Fornasini-Marchesini (F-M) model Ⅱ of 2-D systems are investigated. The corresponding closed-loop systems described by F-M model Ⅱ are obtained via the state feedback.Using the algebraic geometry method, the characteristic polynomial assignment in the closed-loop systems is discussed. In terms of the theory of algebraic geometry, the problem of characteristic polynomial assignment is transferred to the one whether a rational mapping is onto. Sufficient conditions for almost arbitrary assignment coefficients of characteristic polynomial in F-M model Ⅱ of 2-D systems via state feedback are derived, and they are available for multi-input cases. It also has been shown that this method can be applied to assign the characteristic polynomial with output feedback. The sufficient conditions for almost arbitrary assignment coefficients of characteristic polynomial of multi-input 2-D systems described by F-M model Ⅱ with output feedback are established.     

Determination and (re)parametrization of rational developable surfaces

The developable surface is an important surface in computer aided design, geometric modeling and industrial manufactory. It is often given in the standard parametric form, but it can also be in the implicit form which is commonly used in algebraic geometry. Not all algebraic developable surfaces have rational parametrizations. In this paper, the authors focus on the rational developable surfaces. For a given algebraic surface, the authors ?rst determine whether it is developable by geometric inspection, and then give a rational proper parametrization in the affrmative case. For a rational parametric surface, the authors also determine the developability and give a proper reparametrization for the developable surface.     

钢铁企业交叉销售模型的研究与应用

在成熟的市场经济条件下,企业经营的出发点是市场,即客户的需求.钢铁产品作为生产资料,其交易行为有着与消费品不同的特征,正确认识钢铁产品交易行为特征,加强客户关系管理,有利于钢铁生产企业提高市场竞争力.针对此需要,在分析钢铁产品交易行为特征的基础上,提出了钢铁企业交叉销售模型,并对其构建过程和关键技术进行了深入研究,最后应用在某钢铁企业中,为企业制定交叉销售策略提供了科学的决策依据,并取得了良好的效果.     

Stability radius of non-smooth pritchard-salamon systems and the algebraic Riccati equation

The authors discuss the stability radius of the non-smooth Pritchard-Salamon systems under structured perturbations. A formula for the stability radius in terms of the norm of a certain input-output operator is obtained. Furthermore, the relationship between stability radius and the solvability of some type of algebraic Riccati equations is given. This research is supported by the National Natural Science Foundation of China under Grant Nos. 10626057 and 10571165.     

线性系统同时极点配置的代数几何方法

利用代数几何方法,研究两个线性系统状态反馈和输出反馈同时极点配置问题。通过讨论代数几何中的有理映射是否为到上的,来判别线性系统的特征多项式的系数可否几乎任意配置,从而推导出两个线性系统状态反馈和输出反馈同时极点配置的充分条件。将此结论应用到同时镇定问题上,得到了两个线性系统同时镇定的充分条件,并证明了如果两个线性系统存在复反馈同时配置极点,则一定存在实反馈同时配置极点。     

ON THE CONSTRUCTION OF GROEBNER BASIS OF A POLYNOMIAL IDEAL BASED ON RIQUIER-JANET THEORY

As a consequence of a previons study of algebraic differential geometry(see [WU1]) theremay be associated to certain special kinds of differential ideals some well-behaved basis enjoyingsome well-behaved properties.If the differential ideals are further specialized so that theycorrespond to ordinary polynomial ideals then such a well-behaved basis will become the usualGroebner basis of the polynomial ideals while the latter is not known for differential ideals.     

导弹攻防对抗中追逃对策模型与配点求解法

未来的来袭导弹可能具备较强的机动性,其弹道不可预测,针对拦截弹追击此类目标的追逃问题,基于微分对策(differential-game, DG)理论建立追逃博弈模型并给出求解方法。模型在分析两者相对运动的基础上,考虑地球重力和自转的影响,以推力角为控制变量,离地高度、速度和经度角为状态变量,建立微分方程组。然后将追逃DG模型转化为单边最优对策问题;并给出改进的高精度五阶Gauss-Lobatto多项式配点法来近似状态变量对时间的导数,将微分方程组转换为代数约束,降低非线性规划问题复杂程度。最后给出了本文研究的仿真实例。     

认知系统AES-LDPC纠错加密器的设计与性能分析

在多跳的认知系统中,由于不存在可信实体作为服务器控制密钥分发,安全性将面临更大挑战,需要建立完善的加密体系结构来解决这一问题。将高级加密标准AES和在通信纠错领域性能优异的低密度奇偶校验码（low-density parity-check, LDPC）结合,设计出了分组长度为128 bit的六轮宽轨迹加密策略、密钥由128 bit AES密钥和LDPC生成矩阵组成的LDPC纠错加密器。由于LDPC生成矩阵具有更好的扩散性能,使得这种新设计的LDPC纠错加密器能在更少的轮数下具有较好的安全性。最后,通过实验结果验证了AES-LDPC纠错加密器的性能。     

Robust H∞ filter design for uncertain nonlinear discrete systems with state delay

In this paper, we address the problem of robust H∞ filter design for a class of nonlinear discrete-time systems with norm-bounded parameter uncertainty, unknown state delay, and unknown nonlinear disturbance. Firstly, the sufficient condition of the existence of the robust filter is analyzed by the modified Riccati inequalities, such that the filtering process remains robustly stable and a prescribed H∞ performance lever is achieved. Then the filter is characterized in the terms of positive solutions of two algebraic Riccati-like equations, irrespective of the uncertainties, time delays and nonlinearities. The simulation example further shows the validity and the applicability of the proposed approach.     

轨道分析解的改进方法及其应用

主要介绍一种通过改进各类轨道摄动项的表达形式,以优化计算效率的轨道分析解改进方法。以低地球轨道为例,阐述了轨道分析解改进后的具体算法,并通过数值仿真分析验证了算法的有效性和实用性。算法以第一类无奇点根数作为轨道状态量,采用开普勒轨道根数计算各类摄动力的长期、长周期和短周期项,通过较简单的组合形式计算无奇点根数的对应摄动项,实现在保持分析解精度和消除小偏心率奇点的同时,提高计算效率。仿真结果表明,分析解算法的模型精度在1E-5量级,符合一阶分析解理论精度的预期;同时计算速度达到传统分析解算法的4倍左右,可有效提升空间碎片轨道预报的计算效率,具有较强的工程应用价值。