一种新的形态学联想记忆网络模型研究

针对即使在输入模式无噪声,形态学联想记忆在用于异联想时仍不能保证完全回忆的问题,从扩大记忆矩阵的存储空间的角度入手,提出一种新的形态学联想记忆模型——三维存储矩阵的形态学联想记忆来刻画MAM(Morphological Associative Memories)的记忆性能。该模型能够弥补传统形态学联想记忆的记忆矩阵的不足,解决MAM在异联想时不能保证对模式对集实现完全回忆的问题。详细阐述了构建三维存储矩阵的原理与步骤,并通过实例验证三维存储矩阵的形态学联想记忆的记忆性能远远优于传统的形态学联想记忆。     

基于概率的MAM记忆性能模型

针对即使输入模式无噪声,形态学联想记忆在用于异联想时仍不能保证完全回忆的问题,借助概率学知识,提出一个概率模型来刻画形态学联想记忆网络的记忆性能。该概率模型能从整体上正确地反映网络的输入端维数、输出端维数以及模式对的数目对形态学联想记忆的记忆性能的影响趋势,对进一步研究与改进形态学联想记忆,有一定的指导意义。     

形态学联想记忆网络记忆性能的定性分析

形态学联想记忆网络基于其前向映射式的网络结构特点,不管有多少个模式对,都可以用一个存储矩阵来进行存储。记忆单个模式对时,该模式对的矩阵信息完全存储在存储矩阵中,所以可以从该模式对的输入模式正确联想出输出模式,但当网络记忆了多个模式对时,各个模式对之间的相互影响就不可避免地存在,在此对其记忆性能进行定性分析,以期对MAM的研究有所裨益。     

形态学联想记忆存储性能的研究

形态学联想记忆（Morphological Associative Memories,MAM）的存储性能是衡量形态学联想记忆能力大小的重要指标。然而,迄今为止,对形态学联想记忆的存储性能,主要是对异联想形态学联想记忆（hetero-MAM）的存储性能的定量分析和定性刻画并未完成。这是一个悬而未决的理论问题,也是一个MAM应用的实际问题。针对这一问题开展研究,站在概率论的角度,提出一个MAM存储性能的概率模型,并进行了证明。通过定量分析和定性讨论,取得一致结论。研究和分析表明,hetero-MAM的存储性能受到输入模式向量维数n、输出模式向量维数m、以及输入、输出模式对数目K的影响,且三者的影响程度不同。提出的概率模型,对形态学联想记忆的研究、分析、设计和应用,具有一定的启发和帮助。     

形态学联想记忆的研究综述*

通过提炼出来的一个形态学联想记忆的研究框架,可以很清晰地概括出形态学联想记忆的研究成果,从而可以很合理地归纳出形态学联想记忆仍存在的问题以及今后的发展方向。此形态学联想记忆的研究框架对形态学联想记忆的进一步研究具有一定的指导意义。     

对数-指数形态学联想记忆

利用对数和指数算子构建了一种新的形态学联想记忆方法,简称LEMAM.理论分析表明:自联想LEMAM(简称ALEMAM)具有无限存储能力、一步回忆记忆、一定的抵抗腐蚀噪声或膨胀噪声的能力,在输入完全或在一定的噪声范围内,能够保证完全回忆记忆;异联想LEMAM(简称HLEMAM)在输入完全情况下,不能保证完全回忆记忆,但当满足一定条件时,也能够达到完美联想记忆.对比实验结果表明:在一些情况下,LEMAM能够取得较好的联想记忆效果.总体来说,LEMAM丰富了形态学联想记忆的理论和实践,可以作为一种神经计算模型加以研究和利用.     

形态学联想记忆网络的研究进展

形态学联想记忆网络具有无限存储能力、一步回忆记忆、良好地抵抗腐蚀噪声或者膨胀噪声的噪声容限等许多优点.从形态学联想记忆的概念、基本原理、发展脉络、研究新成果,发展趋势和研究方向等多个方面综述了形态学联想记忆网络的研究进展.对形态学联想记忆方面的研究带来了一定的参考价值.     

形态学联想记忆网络的进展研究

20多年来,形态学联想记忆的研究得到了长足的发展。从形态学联想记忆的基本原理、研究新成果等方面对形态学联想记忆网络的进展进行了研究。期望对形态学联想记忆方面的研究带来裨益。     

基于αβ运算的多层联想记忆模型的研究

介绍了αβ运算符的定义和αβ联想记忆矩阵的四种操作。通过四种矩阵操作来实现模式对的培训和回忆。αβ多层联想记忆模型相比形态学联想记忆模型数值计算相对容易。最后,通过αβ多层联想记忆的数字模拟实例验证了αβ多层联想记忆具有良好的回忆性能。     

一种新型双向联想记忆神经网络

提出了一种新型双向联想记忆神经网络,此网络将两个相互关联的模式以模式对的形式存储在由N个连接构成的模式环中,记忆容量为22N数量级,完全消除了假模式对、能够全部或部分地回忆出与输入模式对具有最小Hamming距的被记忆的模式对,同时具有较高的记忆效率和可靠性。连接由“连接状态”和“禁止路径”组成,前者直接存储二进制模式对向量的分量,后者用于消除假模式;此神经网络具有正向联想、逆向联想和自联想方式,使得网络能更灵活有效地满足不同的回忆要求。     

A Bidirectional Hetero-Associative Memory for True-Color Patterns

Classical bidirectional associative memories (BAM) have poor memory storage capacity, are sensitive to noise, are subject to spurious steady states during recall, and can only recall bipolar patterns. In this paper, we introduce a new bidirectional hetero-associative memory model for true-color patterns that uses the associative model with dynamical synapses recently introduced in Vazquez and Sossa (Neural Process Lett, Submitted, 2008). Synapses of the associative memory could be adjusted even after the training phase as a response to an input stimulus. Propositions that guarantee perfect and robust recall of the fundamental set of associations are provided. In addition, we describe the behavior of the proposed associative model under noisy versions of the patterns. At last, we present some experiments aimed to show the accuracy of the proposed model with a benchmark of true-color patterns.     

Behavioural study of median associative memory under true-colour image patterns

Median associative memories (MED-AMs) are a special type of associative memory that substitutes the maximum and minimum operators of a morphological associative memory with the median operator. This associative model has been applied to restore grey scale images and provided a better performance than morphological associative memories when the patterns are altered with mixed noise. Despite their power, MED-AMs have not been adopted in problems related with true-colour patterns. In this paper, we describe how MED-AMs can be applied to problems involving true-colour patterns. Furthermore, a complete study of the behaviour of this associative model in the restoration of true-colour images is performed using a benchmark of 16,000 images altered by different noise types.     

Alpha–Beta bidirectional associative memories: theory and applications

In this work a new Bidirectional Associative Memory model, surpassing every other past and current model, is presented. This new model is based on Alpha–Beta associative memories, from whom it inherits its name. The main and most important characteristic of Alpha–Beta bidirectional associative memories is that they exhibit perfect recall of all patterns in the fundamental set, without requiring the fulfillment of any condition. The capacity they show is 2^min(n,m), being n and m the input and output patterns dimensions, respectively. Design and functioning of this model are mathematically founded, thus demonstrating that pattern recall is always perfect, with no regard to the trained pattern characteristics, such as linear independency, orthogonality, or Hamming distance. Two applications illustrating the optimal functioning of the model are shown: a translator and a fingerprint identifier.     

Implicative Fuzzy Associative Memories

Associative neural memories are models of biological phenomena that allow for the storage of pattern associations and the retrieval of the desired output pattern upon presentation of a possibly noisy or incomplete version of an input pattern. In this paper, we introduce implicative fuzzy associative memories (IFAMs), a class of associative neural memories based on fuzzy set theory. An IFAM consists of a network of completely interconnected Pedrycz logic neurons with threshold whose connection weights are determined by the minimum of implications of presynaptic and postsynaptic activations. We present a series of results for autoassociative models including one pass convergence, unlimited storage capacity and tolerance with respect to eroded patterns. Finally, we present some results on fixed points and discuss the relationship between implicative fuzzy associative memories and morphological associative memories     

形态学联想记忆框架研究

形态学联想记忆(MAM)是一类极为新颖的人工神经网络.典型的MAM实例对象包括:实域MAM(RMAM)、复域MAM(CMAM)、双向MAM(MBAM)、模糊MAM(FMAM)、增强的FMAM(EFMAM)、模糊MBAM(FMBAM)等.它们虽有许多诱人的优点和特点,但有相同的形态学理论基础,本质上是相通的,将其统一在一个MAM框架中是可能的.同时,联想记忆统一框架的建立也是当前的研究重点和难点之一.为此作者构建了一个形态学联想记忆框架.文中首先分析MAM类的代数结构,奠定可靠的MAM框架计算基础;其次,分析MAM类的基本操作和共同特征,抽取它们的本质属性和方法,引入形态学联想记忆范式和算子;最后,提炼并证明主要的框架定理.该框架的意义在于:(1)从数学的角度将MAM对象统一在一起,从而能以更高的视角揭示它们的特性和本质;(2)有助于发现一些新的形态学联想记忆方法,从而解决更多的联想记忆、模式识别、模糊推理等问题.     

Reconstruction of Patterns from Noisy Inputs Using Morphological Associative Memories

Morphological neural networks are based on a new paradigm for neural computing. Instead of adding the products of neural values and corresponding synaptic weights, the basic neural computation in a morphological neuron takes the maximum or minimum of the sums of neural values and their corresponding synaptic weights. By taking the maximum (or minimum) of sums instead of the sum of products, morphological neuron computation is nonlinear before thresholding. As a consequence, the properties of morphological neural networks are drastically different than those of traditional neural network models. In this paper we restrict our attention to morphological associative memories. After a brief review of morphological neural computing and a short discussion about the properties of morphological associative memories, we present new methodologies and associated theorems for retrieving complete stored patterns from noisy or incomplete patterns using morphological associative memories. These methodologies are derived from the notions of morphological independence, strong independence, minimal representations of patterns vectors, and kernels. Several examples are provided in order to illuminate these novel concepts.     

利用动态核的形态联想记忆网络的研究

在文献[1]的基础上,提出了一个基于动态核的形态联想记忆网络方法,特点是同一幅图像,如果其所含的噪声情况不同,则其核也将不同,从而较好地解决了图像含有随机噪声时的联想记忆问题。实验证明,此方法具有良好的性能,双向联想记忆的准确率优于文献[1]中介绍的方法。     

模糊形态联想记忆网络抗随机噪声研究及应用

利用灰度图像分解的思想,结合模糊形态联想记忆网络的方法,提高了模糊形态联想记忆网络对随机噪声的抗噪能力。成功地解决了灰度图像在含有随机噪声时的模糊联想记忆问题,并把该方法推广到对彩色图像的处理,从而给出了一种较好地恢复含噪灰度图像和彩色图像的途径。通过实验,验证了该方法的良好性能,取得了较理想的结果。     

Noise performance of linear associative memories

The performance of two commonly used linear models of associative memories, generalized inverse (GI) and correlation matrix memory (CMM) is studied analytically in the presence of a new type of noise (training noise due to noisy training patterns). Theoretical expressions are determined for the S/N ratio gain of the GI and CMM memories in the auto-associative and hetero-associative modes of operation. It is found that the GI method performance degrades significantly in the presence of training noise while the CMM method is relatively unaffected by it. The theoretical expressions are plotted and compared with the results obtained from Monte Carlo simulations and the two are found to be in excellent agreement