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论文考虑了一种五层结构的正则化模糊神经网络模型,针对网络结构的优化问题给出了该网络模型规则层节点的选取方法和相应的反传播学习规则。同时利用该网络模型对油井压裂的效果进行了预测,起到了辅助决策的作用。实际资料处理结果表明此网络模型对油井压裂效果预测问题具有良好的实用性。 相似文献
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正规化模糊神经网络及在手写体汉字识别中的应用 总被引:1,自引:1,他引:0
为改善手写体汉字识别的性能,提出了一种基于正规化模糊神经网络的识别方法。针对网络结构的优化问题给出了网络模型的规则层节点的选取方法和相应的反传播学习规则。该算法能够充分利用专家制订的“if-then”规则,完善网络的推理结构,提高网络的识别能力,减少噪声因素的影响。实验表明此方法对手写体汉字识别问题具有良好的适应性和实用性。该方法指出了一条进一步提高手写体汉字系统性能的新途径。 相似文献
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考虑了一种五层结构的正规化模糊神经网络模型,针对网络结构的优化问题给出了该网络模型的规则层节点的选取方法和相应的反传播学习规则.对于具有较少数输入节点的情况,该网络有较快的训练速度.油藏测井解释中水淹层的识别是石油开发中特别是开发中后期比较突出的一个问题,复杂的地质条件在测井曲线的表现中具有许多模糊性,在各种模糊条件的组合下油藏水淹表现为强水淹、中水淹、弱水淹和无水淹等情形.将正规模糊神经网络用于油藏测井解释中水淹层的识别以提取测井曲线与水淹级别之间的映射关系,从而实现模糊性油藏测井解释中水淹层的识别.实验表明此方法对解决水淹层识别问题具有良好的适应性和实用性. 相似文献
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基于模糊神经网络的水淹层自动识别 总被引:1,自引:0,他引:1
针对油田水淹层识别存在的模糊性和多解性,提出了一种基于模糊神经网络的水淹层自动识别方法。该方法将神经网络技术所具有的高度自适应性、容错性及固有的并行处理能力与模糊逻辑所具有的模拟人类思维中的模糊综合判别特点有机地结合,实现了多因素模糊综合判断推理来完成水淹层自动识别。采用该方法,对大庆油田135个地层样本进行处理,符合率达87.6%。结果表明该方法对解决水淹层自动识别问题具有良好的适应性,可提高水淹层自动识别的精度。 相似文献
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自动重合闸是提高电力系统供电可靠性、保证电力输电线路安全运行的重要装置,广泛应用于供电输送线中。针对自动重合闸电压判据可能出现误判的情况,文章提出了一种将模糊神经网络应用于单相自动重合闸故障识别的方法,构造了一个具有2个输入、1个输出的模糊神经网络模型,用于识别瞬时性故障与永久性故障,并采用从样本中获取模糊规则的方法和利用Matlab软件对该方法进行仿真实验。仿真结果验证了该方法的可行性和准确性。 相似文献
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交通标志识别技术正在被逐步应用到汽车辅助驾驶领域。但是,遮挡、污损、天气环境变化等因素会严重影响交通标志识别的准确性和稳定性。针对该问题,提出了一种基于孪生神经网络的交通标志编码识别模型。该模型将交通标志的识别问题视为交通标志的卷积特征编码识别问题。通过卷积神经网络对交通标志训练样本和基准样本进行特征提取与编码。再利用孪生神经网络进行编码对比,结合对比损失函数对编码器训练调整。通过全连接层对输入通路的标志卷积编码进行重新组合与分类,从而实现交通标识的识别。实验结果表明,所提的基于改进孪生神经网络的编码器模型对存在运动模糊与遮挡的标志图像能生成有效、鲁棒的特征编码,相较于其他先进算法,具有更高的识别准确率。 相似文献
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针对非线性辨识问题,基于改进的T-S模型,提出一种自适应模糊神经网络模型(AFNN)。首先,基于模糊竞争学习算法确定系统的模糊空间和模糊规则数,并得出每个样本对每条规则的适用程度。其次,利用卡尔曼滤波算法在线辨识AFNN的后件参数。AFNN具有结构简洁,逼近能力强,能够显著提高辨识精度,并且辨识的模糊模型简单有效。最后,将该AFNN用于非线性系统的模糊辨识,仿真结果验证了该方法的有效性。 相似文献
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An algorithm for bounded-error identification of nonlinear systems based on DC functions 总被引:1,自引:0,他引:1
This paper presents a guaranteed method for the parameter estimation of nonlinear models in a bounded-error context. This method is based on functions which consists of the difference of two convex functions, called DC functions. The method considers DC representations of the functional form of the dynamic system to obtain an outer bound of the set of parameters that are consistent with the measurements, the system and the considered bounded error. At each iteration, the proposed algorithm solves several convex optimization problems to discard from the initial search region subregions that are proved not consistent. This operation is repeated while the obtained solution is improved. Four examples are provided to clarify the proposed identification algorithm. 相似文献
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A virtual closed loop method for closed loop identification 总被引:2,自引:0,他引:2
Indirect methods for the identification of linear plant models on the basis of closed loop data are based on the use of (reconstructed) input signals that are uncorrelated with the noise. This generally requires exact (linear) controller knowledge. On the other hand, direct identification requires exact plant and noise modelling (system in the model set) in order to achieve accurate results, although the controller can be non-linear. In this paper, a generalized approach to closed loop identification is presented that includes both methods as special cases and which allows novel combined methods to be generated. Besides providing robustness with respect to inexact controller knowledge, the method does not rely on linearity of the controller nor on exact noise modelling. The generalization is obtained by balancing input-noise decorrelation against noise whitening in a user-chosen flexible fashion. To this end, a user-chosen virtual controller is used to parametrize the plant model, thereby generalizing the dual-Youla method to cases where knowledge of the controller is inexact. Asymptotic bias and variance results are presented for the method. Also, the benefits of the approach are demonstrated via simulation studies. 相似文献
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变风量空调末端(VAVBOX)是变风量系统的关键部位,其运行的状况将直接影响空调系统的整个运行效果。本文主要论述了对压力有关型变风量末端控制回路进行了系统辨识,风阀模型采用开环辨识的方法,房间模型辨识中采用了闭环辨识。为研究变风量空调末端(VAVBOX)在室内温度方面的精确控制与抗扰问题打下了坚实基础。 相似文献
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An algorithm for the exact least-squares identification of an approximate continuous-time time-delay system is derived and its operation verified by simulation. 相似文献
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An on-line parameter identification problem is posed and solved for discrete-time systems with general knowledge on the level of the inherent information noise. The knowledge can be the bound on either the magnitude or the finite-index
p norm, pε[1, ∞), of the noise. Based on the knowledge, a switching type gradient algorithm (or called gradient algorithm with dead zone) is proposed to estimate the parameters of the system from the available input-output data. In spite of the existence of the noise, this on-line algorithm guarantees that the estimation error is monotonically decreasing, and the parameter estimate is convergent to a steady-state value under a mild condition. Furthermore, the algorithm is stable in the sense that the estimation error will converge to zero as the bound on the noise gradually diminishes. 相似文献
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Håkan Hjalmarsson Jonas Mårtensson Cristian R. Rojas Torsten SöderströmAuthor vitae 《Automatica》2011,47(12):2704-2712
Errors-in-variables estimation problems for single-input–single-output systems with Gaussian signals are considered in this contribution. It is shown that the Fisher information matrix is monotonically increasing as a function of the input noise variance when the noise spectrum at the input is known and the corresponding noise variance is estimated. Furthermore, it is shown that Whittle’s formula for the Fisher information matrix can be represented as a Gramian and this is used to provide a geometric representation of the asymptotic covariance matrix for asymptotically efficient estimators. Finally, the asymptotic covariance of the parameter estimates for the system dynamics is compared for the two cases: (i) when the model includes white measurement noise on the input and the variance of the noise is estimated, and (ii) when the model includes only measurement noise on the output. In both cases, asymptotically efficient estimators are assumed. An explicit expression for the difference is derived when the underlying system is subject only to measurement noise on the output. 相似文献
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曾建一 《自动化技术与应用》2007,26(8):74-76
由于人体指纹具有唯一性和不变性,使得指纹识别与传统身份识别的方法相比具有更高的安全性和易用性.本文阐述了生物特征识别的发展历史、应用背景,并着重介绍指纹识别系统的工作流程、分类及研究现状. 相似文献