共查询到20条相似文献，搜索用时 171 毫秒
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利用P-集合的动态特性,给出信息图像换变,提出信息图像变换的概念、构成结构;信息图像变换属性特征和度量特征,提出信息图像变换-还原定理,给出信息图像变换在图像信息系统中的应用。 相似文献
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基于信息安全交换的目的,利用P-集合的动态特性,对传输的真信息进行加密隐藏的方法,把真信息隐藏在假信息内,实现信息的安全传输.提出F2信息隐藏与还原定理,给出辨识方法,利用这些结果,给出F-信息隐藏与还原的应用,通过实验验证了它的合理性.实现了信息的安全传输.P-集合是研究动态信息系统的一个新理论和新方法. 相似文献
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基于可变模糊集的质变与量变定理 总被引：1，自引：0，他引：1
陈守煜 《科技成果管理与研究》2010,(4):53-55
根据可变模糊集理论率先给出唯物辩证法哲学三大规律之一：质量互变规律的严密的数学定理——质变与量变定理。指出可变模糊集相对差异函数与集对分析差异度的区别。 相似文献
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针对三维空间插值各向异性与属性变化难以结合的问题,提出了一种以地统计学为基础,实现对具有各向异性地理现象的三维空间插值方法。首先,利用分层采样的方法收集青海湖周边土壤钾含量值,并进行采样优化;然后,采用主成分分析(Principal Component Analysis,PCA)对采样数据进行属性变化的方向特征分析,提取属性的特征方向;接着,进行结构特征分析,拟合三个轴上的变异函数曲线,构建各向异性变异函数的统一套合模型,获得土壤钾含量的三维空间插值结果;最后,与局部径向基函数(Local radial basis function, LRBF)和三维普通克里金(3D ordinary kriging, 3D-OK)方法比较,这种方法对地理属性进行结构特征分析,拟合变异曲线,能够反映地理现象在三维空间中的各向异性特征,从而规范构建三维变异函数的统一套合模型,且插值精度高,是一种可行的顾及各向异性三维空间插值方法。 相似文献
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大学的复变函数课本中给出了一维复欧式空间留数定理的证明,在黎曼曲面中利用复流形的方法给出了黎曼面上的留数定理的一种证明,该文用层的上同调的方法给出黎曼面上留数定理的另外一种证明. 相似文献
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杨文中 《内蒙古科技与经济》2002,(2):104-106
极限理论是数学分析的基础。一般的分析教材中都给出了斯托尔兹定理 ,利用它可以求一些数列的极限 ,但斯托尔兹定理本身并不完美 ,它仅仅适用于数列。本文对斯托尔兹定理进行了推广 ;推广到函数的情形 ,并给出了推广的斯托尔兹定理的几个应用 ,说明了推广后的斯托尔兹定理比原定理应用范围更广 相似文献
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基于绿色产品的QFD中技术特性相对权重的优化 总被引：1，自引：0，他引：1
质量功能展开(QFD)是将顾客的需求转化为产品的技术特性以满足市场需求的一个系统过程。基于三角模糊数的加权平均法求得技术特性的初始相对权重,考虑到绿色产品应同时考虑成本和环境因素,引入三角模糊的DEA方法对技术特性的初始相对权重进行优化;然后,由技术特性改进目标值对技术特性的相对权重进行进一步优化,并在各α水平截集下采用期望值法对技术特性相对权重进行去模糊处理;最后,通过算例对优化方法进行了验证。 相似文献
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《Journal of The Franklin Institute》2021,358(18):9483-9509
This paper mainly studies the design of iterative learning constrained model predictive fault–tolerant control for batch processes accompanied by multi–delays, interference and actuator failures. Firstly, an equivalent 2D–Roesser model with multi–delays is established. The definition of invariant set is proposed. The sufficient conditions with invariant set characteristics are established. After that the predictive fault-tolerant controller is designed with terminal constraints against external disturbances. In this paper, Lyapunov–Razumikhin Function (LRF) is used to form Lyapunov–Krasovskii Function (LKF) to construct the sufficient condition for the predictive control system that satisfies the terminal constraint condition. Moreover, the system state still remains invariant set characteristics. This method has certain advantages in controller design and calculation. In addition, it has the characteristics of simple design and small computation, and is especially suitable for small delay systems. Finally, a simulation experiment in the nonlinear batch reactor is carried out. Compared with the traditional one-dimensional (1D) method, the presented strategy has better performance through simulation experiment. 相似文献
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阐述了当前Linux防火墙的发展状况及分类,给出了Linux网络防火墙Netfiher在IPV4网络环境下框架挂接的结构及数据包的传输流程,并描述了在挂接点上注册的钩子函数的功能。最后结合Netfilter处理数据包原理,介绍了简单防火墙的实现。 相似文献
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In this work, the problem of sliding mode control is considered for a class of Markovian jumping systems. The packet dropout may happen when the state information is transmitted from the sensor to the controller. By means of an estimator for lost signals, an integral-like sliding function is constructed. And then, a sliding mode controller involving in dropout probability is designed such that the effect of packet losses can be effectively attenuated. Besides, the analysis on both the stability of sliding mode dynamics and the reachability of sliding surface are made. Finally, the numerical simulation results are given. 相似文献
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《Journal of The Franklin Institute》2022,359(8):3492-3516
In this paper, the problem of the predefined-time tracking with time-varying output constraints (TVOC) is investigated for a class of nonlinear strict-feedback systems. First, the sufficient conditions for the studied problem are presented. Then, a recursive design algorithm of the controller is proposed by backstepping technique. A novel stabilizing function is constructed by adding a fractional term, which is capable of decreasing the asymmetric time-varying Barrier Lyapunov Function (BLF) to the origin within any desired settling time. After that, it is shown that under our proposed control, all the closed-loop signals are bounded, and the tracking error converges to zero within any desired settling time and remains zero thereafter without the violation of the output constraint. The settling time in this paper is not only independent of the design parameters, nor does it depend on the initial conditions, and can be set according to per our will. Finally, two examples are given to illustrate the effectiveness of the proposed method. 相似文献
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Xi-Sheng Zhan Zhi-Hong Guan Xian-He Zhang Fu-Shun Yuan 《Journal of The Franklin Institute》2013,350(10):3205-3216
The optimal tracking problem for single-input–single-output (SISO) networked control system over a communication channel with packet dropouts is studied in this paper. The tracking performance is measured by the energy of the error signal between the output of the plant and the reference signal. It is shown that the optimal tracking performance is constrained by nonminimum phase zeros, unstable poles, the characteristics of the reference signal and packet dropout probability, and the optimal controller is obtained. It is also shown that when the communication constraint does not exist, the optimal tracking performance reduces to the existing normal tracking performance of the control system without a communication channel. The result shows how the packet dropouts probability of a communication channel may fundamentally constrain a control system's tracking ability. Some typical examples and simulations are given to illustrate the theoretical results. 相似文献
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在描述BACnet控制器嵌入式系统整个工作流程的基础上,详细介绍了在软件模块设计过程中,服务器TSM的工作原理框架,BACnet控制器的各种服务功能分析,对BACnet-APDU编解码作了介绍。最后给出了基于嵌入式系统开发BACnet控制器的软件框架。 相似文献
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Engang Tian Kunyu Wang Xia Zhao Shibin Shen Jinliang Liu 《Journal of The Franklin Institute》2019,356(13):7210-7223
In this paper, the H∞ control problem is investigated for a class of networked control systems with network-induced delay. A memory event-triggered scheme (METS) is proposed to reduce the redundant packet transmission in the network channel. Different from the normal event-triggered scheme (ETS), some recent released packets are stored at the event generator and controller sides, which are utilized for the first time to generate the triggered events and design the memory-based controller. The proposed METS has the following two merits. (1) The information of certain recent released signals are first utilized, which helps to improve the triggering instants at the crest or trough of the responses. (2) A state-dependent time-varying threshold parameter is designed, which can adjust the packet transmission rate according to the information of the state. Based on the proposed METS, a memory event-triggered controller is designed, the controller feedback gains and triggering parameters can be co-designed by solving a set of linear matrix inequalities. Finally, an example is given to illustrate the effectiveness of the proposed method. 相似文献
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In this brief, a switching fault-tolerant control (FTC) scheme is presented for a moving vehicle-mounted flexible manipulator subject to state constraints. The dynamic characteristics of the system are represented by coupled ordinary differential equations and partial differential equations (ODEs–PDEs). When actuators are healthy, vibration control and position regulations can be realized without violation of the given constraints based on a Barrier Lyapunov Function (BLF). Moreover, a switching strategy is introduced to prevent the transgression of constraints even under actuator failure by detecting actuator faults as-assisted by the proposed monitoring functions. The closed-loop states are kept within the given bounds under FTC laws. By extending LaSalle's Invariance Principle to an infinite dimension, the asymptotic stability of the fault-free closed-loop system is strictly verified. Simulation results demonstrate the effectiveness of the proposed approach. 相似文献
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通过使用功能等价法，实现了传统文献到网络文献的迁移。从表面上看，该方法是一种类似功能的传递，实质上它是传统文献在网络环境中的嫁接。它既适应了网络文献灵活多变的特征，又满足了传统文献引用价值的平衡，是网络文献引用规范化的一个有益的尝试。 相似文献