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1.
基于约束区域的BSB联想记忆模型   总被引:2,自引:0,他引:2  
提出一种根据联想记忆点设计基于约束区域的BSB(Brain-State-inm-a-Box)神经网络模型,它保证了渐近稳定的平衡点集与样本点集相同,不渐近稳定的平衡点恰为实际的拒识状态,并且吸引域分布合理,从而将ESB完善为理想的联想记忆器。  相似文献   

2.
基于线性规划的联想记忆神经网络模型   总被引:2,自引:2,他引:0  
陶卿  孙德敏 《计算机学报》2001,24(4):377-381
提出一种基于优化线性函数的神经网络联想记忆器,打破了将待识别模式作为网络起始点的常规,它能保证渐近稳定的平衡点集与样本点集相同,吸引域分布合理,不渐近稳定的平衡点恰为实际的拒识模式,并且电路实现容易,对拒识模式有清楚的解释。理论分析和计算机模拟都表明本文的模型是理想的联想记忆器,还可降低对硬件的精度要求。  相似文献   

3.
离散Hopfield联想记忆神经网络的渐近行为   总被引:7,自引:0,他引:7  
金聪 《计算机学报》2002,25(2):153-157
该文对一类离散Hopfield联想记忆神经网络的渐近行为进行了讨论,首先提出这类I/O函数取为Sigmoid型函数的离散Hopfield联想记忆神经网络的数学模型,讨论并给出了这种模型的一系列性质,例如运动轨迹的有界性,平衡点的唯一性以及渐近稳定性等,得到了平衡点渐近稳定的充分条件,检验这种神经网络模型的渐近稳定性,只需要测试一个特定矩阵的定性性质或特定不等式即可,这些结果可用于离散Hopfield联想记忆神经网络的综合过程。  相似文献   

4.
离散Hopfield双向联想记忆神经网络的稳定性分析   总被引:12,自引:0,他引:12  
金聪 《自动化学报》1999,25(5):606-612
首先将离散Hopfield双向联想记忆神经网络转化成一个特殊的离散Hopfield网络 模型.在此基础上,对离散Hopfield双向联想记忆神经网络的全局渐近稳定性和全局指数稳 定性进行了新的分析.证明了神经网络连接权矩阵在给定的约束条件下有唯一的而且是渐近 稳定的平衡点.利用Lyapunov方程正对角解的存在性得到了几个判定平衡点为全局渐近稳 定和全局指数稳定的充分条件.这些条件可以用于设计全局渐近稳定和全局指数稳定的神经 网络.所做的分析扩展了以前的稳定性结果.  相似文献   

5.
噪声环境中时滞双向联想记忆神经网络指数稳定   总被引:2,自引:0,他引:2  
任何系统实际上都是在噪声环境中进行工作的.对处在噪声强度已知的噪声环境下双向联想记忆(BAM)神经网络,其平衡点具有指数渐近稳定性是网络进行异联想记忆的基础.构造一个适当的Lyapunov函数,应用It^o公式、M矩阵等工具讨论了在噪声环境下具有时滞的BAM神经网络概率1指数渐近稳定,得到了指数稳定的代数判据和两个推论,此判据只需验证仅由网络参数构成的矩阵是M矩阵即可,给网络设计带来方便.本文所得结果包括相关文献中确定性结果作为特例.  相似文献   

6.
针对一类具有离散时滞和参数范数有界的不确定性中立联想记忆神经网络的全局渐近鲁棒稳定性问题进行了研究.通过应用范数理论和矩阵不等式分析方法,并构造合适的Lyapunov-Krasovskii泛函,推导出了与时滞无关的新稳定性判定准则,用于保证神经网络的平衡点是全局渐近鲁棒稳定的.该准则中包含的未知参数少、计算复杂度低,易于验证.仿真算例验证了新判定准则的有效性.  相似文献   

7.
一类时延反馈神经网络的稳定性及吸引域的估计   总被引:3,自引:0,他引:3  
反馈型神经网络由于具有极为丰富的动力学行为和整体计算能力(如优化、联想、振荡和混饨)而倍受关注,近几年的研究表明,当网络的时延足够小时,具有延时的对称Hopfield型神经网络和无时延情况一样也是全局稳定的.本文通过构造适当Lyapunov泛函的方法,对一类具有时延的反馈型神经网络平衡点的渐近稳定性进行了分析,得到了平衡点渐近稳定的充分条件:要检验一个有时间延迟的反馈型神经网络的稳定性,只要测试一个特定矩阵的定性性质或一个特定不等式即可.最后我们也提供了一种估计网络渐近稳定平衡点吸引域的方法.  相似文献   

8.
陈松灿  朱梧 《软件学报》1998,9(11):814-819
提出了一个新的高阶双向联想记忆模型.它推广了由Tai及Jeng所提出的高阶双向联想记忆模型HOBAM(higher-order bidirectional associative memory)及修正的具有内连接的双向联想记忆模型MIBAM(modified intraconnected bidirectional associative memory),通过定义能量函数,证明了新模型在同步与异步更新方式下的稳定性,从而能够保证所有被训练模式对成为该模型的渐近稳定点.借助统计分析原理,估计了所提模型的存储容量.计算机模拟证实此模型不仅具有较高的存储容量,而且还具有较好的纠错能力.  相似文献   

9.
当神经网络应用于最优化计算时,理想的情形是只有一个全局渐近稳定的平衡点,并且以指数速度趋近于平衡点,从而减少神经网络所需计算时间.研究了带时变时滞的递归神经网络的全局渐近稳定性.首先将要研究的模型转化为描述系统模型,然后利用Lyapunov-Krasovskii稳定性定理、线性矩阵不等式(LMI)技术、S过程和代数不等式方法,得到了确保时变时滞递归神经网络渐近稳定性的新的充分条件,并将它应用于常时滞神经网络和时滞细胞神经网络模型,分别得到了相应的全局渐近稳定性条件.理论分析和数值模拟显示,所得结果为时滞递归神经网络提供了新的稳定性判定准则.  相似文献   

10.
联想记忆神经网络局部指数稳定的充要条件及特征函数   总被引:1,自引:0,他引:1  
讨论非线性连续联想记忆神经网络平衡点局部指数稳定的判定条件及平衡点指数 吸引域的估计,得到了平衡点局部指数稳定的充要条件,并引入一个特征函数,可以判定平衡 点的邻域是否为指数吸引域.文中给出一族范数下(所有单调范数)网络局部或全局指数稳定 的判定条件,推广了已知文献在特定范数下所得到的结论.  相似文献   

11.
A novel neural network is proposed in this paper for realizing associative memory. The main advantage of the neural network is that each prototype pattern is stored if and only if as an asymptotically stable equilibrium point. Furthermore, the basin of attraction of each desired memory pattern is distributed reasonably (in the Hamming distance sense), and an equilibrium point that is not asymptotically stable is really the state that cannot be recognized. The proposed network also has a high storage as well as the capability of learning and forgetting, and all its components can be implemented. The network considered is a very simple linear system with a projection on a closed convex set spanned by the prototype patterns. The advanced performance of the proposed network is demonstrated by means of simulation of a numerical example.  相似文献   

12.
In this article we present techniques for designing associative memories to be implemented by a class of synchronous discrete-time neural networks based on a generalization of the brain-state-in-a-box neural model. First, we address the local qualitative properties and global qualitative aspects of the class of neural networks considered. Our approach to the stability analysis of the equilibrium points of the network gives insight into the extent of the domain of attraction for the patterns to be stored as asymptotically stable equilibrium points and is useful in the analysis of the retrieval performance of the network and also for design purposes. By making use of the analysis results as constraints, the design for associative memory is performed by solving a constraint optimization problem whereby each of the stored patterns is guaranteed a substantial domain of attraction. The performance of the designed network is illustrated by means of three specific examples.  相似文献   

13.
Synthesis of Brain-State-in-a-Box (BSB) based associative memories   总被引:2,自引:0,他引:2  
Presents a novel synthesis procedure to realize an associative memory using the Generalized-Brain-State-in-a-Box (GBSB) neural model. The implementation yields an interconnection structure that guarantees that the desired memory patterns are stored as asymptotically stable equilibrium points and that possesses very few spurious states. Furthermore, the interconnection structure is in general non-symmetric. Simulation examples are given to illustrate the effectiveness of the proposed synthesis method. The results obtained for the GBSB model are successfully applied to other neural network models.  相似文献   

14.
This paper concerns reliable search for the optimally performing GBSB (generalized brain-state-in-a-box) neural associative memory given a set of prototype patterns to be stored as stable equilibrium points. First, we observe some new qualitative properties of the GBSB model. Next, we formulate the synthesis of GBSB neural associative memories as a constrained optimization problem. Finally, we convert the optimization problem into a semidefinite program (SDP), which can be solved efficiently by recently developed interior point methods. The validity of this approach is illustrated by a design example.  相似文献   

15.
Recurrent correlation associative memories   总被引:8,自引:0,他引:8  
A model for a class of high-capacity associative memories is presented. Since they are based on two-layer recurrent neural networks and their operations depend on the correlation measure, these associative memories are called recurrent correlation associative memories (RCAMs). The RCAMs are shown to be asymptotically stable in both synchronous and asynchronous (sequential) update modes as long as their weighting functions are continuous and monotone nondecreasing. In particular, a high-capacity RCAM named the exponential correlation associative memory (ECAM) is proposed. The asymptotic storage capacity of the ECAM scales exponentially with the length of memory patterns, and it meets the ultimate upper bound for the capacity of associative memories. The asymptotic storage capacity of the ECAM with limited dynamic range in its exponentiation nodes is found to be proportional to that dynamic range. Design and fabrication of a 3-mm CMOS ECAM chip is reported. The prototype chip can store 32 24-bit memory patterns, and its speed is higher than one associative recall operation every 3 mus. An application of the ECAM chip to vector quantization is also described.  相似文献   

16.
Conventional associative memory networks perform "noncompetitive recognition" or "competitive recognition in distance". In this paper a "competitive recognition" associative memory model is introduced which simulates the competitive persistence of biological species. Unlike most of the conventional networks, the proposed model takes only the prototype patterns as its equilibrium points, so that the spurious points are effectively excluded. Furthermore, it is shown that, as the competitive parameters vary, the network has a unique stable equilibrium point corresponding to the winner competitive parameter and, in this case, the unique stable equilibrium state can be recalled from any initial key.  相似文献   

17.
The exponential bidirectional associative memory (eBAM) has been proposed and proved to be a stable and high capacity associative neural network. However, the intrinsic structure and the evolution functions of this network restrict the representation of patterns to be either bipolar or binary vectors. We consider the promising development of multi-valued systems and then design a multi-valued discrete eBAM (MV-eBAM). The multi-valued eBAM has been proved to be asymptotically stable under certain constraints. Although MV-eBAM is also verified to possess high capacity by thorough simulations, there are important characteristics to be explored, including the absolute lower bound of the radix, and the approximate capacity. In order to estimate the capacity of the MV-eBAM, a modified evolution equation is also proposed. Hence, an analytic solution is derived. Besides, a radix searching algorithm is presented such that the absolute lower bound of the radix for this MV-eBAM can be found.  相似文献   

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