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图像矢量量化—频率敏感自组织特征映射算法 总被引:17,自引:0,他引:17
用神经网络实现图像矢量量化是一种非常有效的方法,本文在分析自组织特征映射(SOFM)算法的基础上,提出了一种频率敏感自组织特征映射(FSOFM)算法,并对网络学习训练参数的优化进行了探讨。实验表明,FSOFM算法优于SOFM算法。 相似文献
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多媒体通信中智能化媒体内同步机制 总被引:2,自引:0,他引:2
本文提出了一种智能化视频流量的预测和同步机制(IFSM),它由BP神经网络流量预测器(BPNN)、输出缓冲区和基于模糊神经网络(FNN)的输出速率决策器所组成。BPNN采用一种在线训练的BP神经网络预测在将来的一定时间间隔(FI)内的平均分组速率,FNN决策器根据预测的流量特性和缓冲区中的分组数动态地调节下一个分组输出的时间。仿真结果表明:与窗口机制相比,IFSM能够使视频流量取得较高的连续性和较低的时延,并且由于FNN的学习能力,IFSM可以自适应地调节相应参数以满足不同的服务质量的要求。 相似文献
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EEPROM单元结构的变革及发展方向 总被引:5,自引:2,他引:3
扼要阐述了电可擦除可编程只读存储器(EEPROM)发展史上的各种结构如FAMOS、MNOS、SIMOS、DIFMOS、FETMOS(FLOTOX)等,比较了它们的优缺点,着重论述了EEPROM结构今后的变革方向。 相似文献
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复数FIR DF设计的神经网络优化方法 总被引:2,自引:0,他引:2
本文基于人工神经网络(ANN)能量函数优化理论,提出了一种FIR数字滤波器(DF)神经网络优化设计(NNO)方法的理论框架。该理论将实数与复数FIR DF设计工作统一起来。表征设计质量的加权均方误差被当作ANN能量函数,以此导出FIR-NNO的Lyapunov方程,文中说明了算法实现的基本原则,并给出了两个实数线位和一个复数非线性相位FIR DF设计实例。通过与其它几种方法的比较证明了该方法的有效 相似文献
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单体模糊神经网络:在智能控制中的应用及VLSI实现 总被引:2,自引:0,他引:2
本文提出了一种融合人工神经网络与模糊集合理论思想的网络结构一单体模糊神经网络(MFNNs)在对该网络结构性质进行讨论的基础上,设计了该系统在智能控制领域中的应用,同时介绍了采用2μm电流型多值逻辑CMOS集成电路系统进行的设计和实现的情况,研究表明这一新型的模糊神经网络有广阔的应用前景。 相似文献
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图像矢量量化(VQ)是图像压缩算法中的重要环节,而在VQ中起决定性因素的又是能否构造出性能优异的码书,本文在比较LBG,SOFM和改进的SOFM优缺点的基础上,采用具有结构自适应特性的自组织神经网络(SASONN)来构造码书,克服了SOFM算法的网络映射欠准确、神经元过利用等弊端,并将结果应用在图像压缩编码算法(VQ+DPCM+DCT)中,实验结果表明,主客观效果良好。 相似文献
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基于自组织特征映射神经网络的聚类分析 总被引:1,自引:0,他引:1
在深入研究自组织特征映射(Self-organizing Feature Mapping,SOFM)神经网络的结构和聚类算法的基础上,阐述了SOFM网络的建立方法.以随机二维向量的聚类为例,利用所建立的SOFM网络模型对输入的随机二维向量进行聚类,并着重研究了输出层神经元拓扑结构、训练步数对聚类结果的影响以及在相同拓扑结构条件下,SOFM网络模型的权值向量的调整过程.仿真结果表明:在输出层神经元节点形式为六边型条件下,输出层神经元的个数越多,SOFM网络模型的聚类结果就越准确;在相同的拓扑结构条件下,训练步数越大,SOFM网络聚类结果越准确,但过大的训练步数对于聚类结果的影响甚微. 相似文献
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汪烈军 《微电子学与计算机》2007,24(1):106-109,115
针对结构自适应自组织神经网络神经元分布的特点和节点生长-删除算法的局限性.提出了一种改进的结构自适应自组织神经网络。根据神经元的学习速率、领域、兴奋度及相似阈值等状态信息.该算法可适应地调整神经网络的结构,克服了现有结构自适应神经网络的局限性。具有很好的聚类和泛化能力。实验结果表明该算法对样本的聚类有很好的效果并且具有很好的泛化能力。 相似文献
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Halici U. Ongun G. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1996,84(10):1497-1512
In this paper, a neural network structure based on self organizing feature maps (SOFM) is proposed for fingerprint classification. In order to be able to deal with fingerprint images having distorted regions, the SOFM learning and classification algorithms are modified. For this purpose, the concept of “certainty” is introduced and used in the modified algorithms. This fingerprint classifier together with a fingerprint identifier, constitute subsystems of an automated fingerprint identification system, named HALafis. Our results show that a network that is trained with a sufficiently large and representative set of samples can be used as an indexing mechanism for a fingerprint database, so that it does not need to be retrained for each fingerprint added to the database 相似文献
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Chakraborty B. Kaustubha R. Hegde A. Pereira A. 《Geoscience and Remote Sensing, IEEE Transactions on》2001,39(12):2722-2725
A self-organizing feature map (SOFM), a kind of artificial neural network (ANN) architecture, is used in this work for continental shelf seafloor sediment classification. Echo data are acquired using an echosounding system from three types of seafloor sediment areas. Excellent classification (~100%) for an ideal output neuron grid size of 15×1 is obtained for a moving average of 35 input snapshots 相似文献
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容差模拟电路故障模糊诊断方法及其实现 总被引:1,自引:3,他引:1
提出了基于SOFM神经网络的容差模拟电路故障模糊诊断方法及其实现。该方法将网络撕裂法和SOFM神经网络相结合进行故障测试.并运用所设计的模糊逻辑神经网络系统判断测试条件,定位容差模拟电路的子网络级故障。仿真试验表明该方法故障定位精确度高。撕裂迅速,有利于大规模容差模拟电路故障诊断的实现。 相似文献
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神经网络的特征映射聚类算法研究 总被引:1,自引:0,他引:1
自组织特征映射作为一种神经网络方法,在数据挖掘、机器学习和模式分类中得到了广泛应用。他将高维输入空间的数据映射到一个低维、规则的栅格上,从而可以利用可视化技术探测数据的固有特性。说明自组织特征映射神经网络的工作原理和具体实现算法,并在对已有神经网络聚类分析方法概括和总结的基础上,结合一些实验数据、仿真数据对自组织特征映射算法进行研究,得出了一些有意义的结论。 相似文献
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Shih-Chii Liu 《Analog Integrated Circuits and Signal Processing》2002,31(1):47-53
We describe an aVLSI network consisting of a group of excitatory neurons and a global inhibitory neuron. The output of the inhibitory neuron is normalized with respect to the input strengths in a manner that is useful in any system where we wish the output signal to code only the strength of the inputs, and not be dependent on the number of active inputs. The circuitry in each neuron is equivalent to that in Lazzaro's winner-take-all (WTA) circuit [1] with one additional transistor and a voltage reference. As in Lazzaro's circuit, the outputs of the excitatory neurons code for the neuron with the largest input. The novel feature is that multiple winners can be chosen (soft-max). By varying one parameter, the network can operate in a soft-max regime or a WTA regime. We show results from two different fabricated networks. 相似文献
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Kyan MJ Guan L Arnison MR Cogswell CJ 《IEEE transactions on bio-medical engineering》2001,48(11):1306-1318
An investigation of local energy surface detection integrated with neural network techniques for image segmentation is presented, as applied in the feature extraction of chromosomes from image datasets obtained using an experimental confocal microscope. Use of the confocal microscope enables biologists to observe dividing cells (living or preserved) within a three-dimensional (3-D) volume, that can be visualised from multiple aspects, allowing for increased structural insight. The Nomarski differential interference contrast mode used for imaging translucent specimens, such as chromosomes, produces images not suitable for volume rendering. Segmentation of the chromosomes from this data is, thus, necessary. A neural network based on competitive learning, known as Kohonen's self-organizing feature map (SOFM) was used to perform segmentation, using a collection of statistics or features defining the image. Our past investigation showed that standard features such as the localized mean and variance of pixel intensities provided reasonable extraction of objects such as mitotic chromosomes, but surface detail was only moderately resolved. In this current work, a biologically inspired feature known as local energy is investigated as an alternative image statistic based on phase congruency in the image. This, along with different combinations of other image statistics, is applied in a SOFM, producing 3-D images exhibiting vast improvement in the level of detail and clearly isolating the chromosomes from the background. Index Terms-DIC, differential interference contrast, feature extraction, feature space, image segmentation, local energy, Morlet wavelet, phase congruency, self organizing feature map, SOFM. 相似文献