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采用人工神经网络方法研究了晶体结构,强度,应力集中,晶粒尺寸,加速速度和温度与冷脆断裂关系的方法。 相似文献
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设计了一种可用于步行器精密测力系统标定的3层反向传播人工神经网络模型,以测力系统12导联应变片电桥输出电压作为网络输入向量,6个负载分量力作为网络输出向量,并通过目标误差下的绝对误差和对比确定出模型隐含层的最优神经元数.有关误差校验结果表明,使用该神经网络技术标定后的系统最大单向力精度误差为7.78%,最大交叉干扰为7.49%,与传统的线性标定方法相比,能够有效提高步行器受载力的测量精度并大大降低干扰误差,未来有望为步行器助行康复训练效果的准确监控和评估提供帮助. 相似文献
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Diabetes is associated with many complications that could lead to death. Diabetic retinopathy, a complication of diabetes, is difficult to diagnose and may lead to vision loss. Visual identification of micro features in fundus images for the diagnosis of DR is a complex and challenging task for clinicians. Because clinical testing involves complex procedures and is time-consuming, an automated system would help ophthalmologists to detect DR and administer treatment in a timely manner so that blindness can be avoided. Previous research works have focused on image processing algorithms, or neural networks, or signal processing techniques alone to detect diabetic retinopathy. Therefore, we aimed to develop a novel integrated approach to increase the accuracy of detection. This approach utilized both convolutional neural networks and signal processing techniques. In this proposed method, the biological electro retinogram (ERG) sensor network (BSN) and deep convolution neural network (DCNN) were developed to detect and classify DR. In the BSN system, electrodes were used to record ERG signal, which was pre-processed to be noise-free. Processing was performed in the frequency domain by the application of fast Fourier transform (FFT) and mel frequency cepstral coefficients (MFCCs) were extracted. Artificial neural network (ANN) classifier was used to classify the signals of eyes with DR and normal eye. Additionally, fundus images were captured using a fundus camera, and these were used as the input for DCNN-based analysis. The DCNN consisted of many layers to facilitate the extraction of features and classification of fundus images into normal images, non-proliferative DR (NPDR) or early-stage DR images, and proliferative DR (PDR) or advanced-stage DR images. Furthermore, it classified NPDR according to microaneurysms, hemorrhages, cotton wool spots, and exudates, and the presence of new blood vessels indicated PDR. The accuracy, sensitivity, and specificity of the ANN classifier were found to be 94%, 95%, and 93%, respectively. Both the accuracy rate and sensitivity rate of the DCNN classifier was 96.5% for the images acquired from various hospitals as well as databases. A comparison between the accuracy rates of BSN and DCNN approaches showed that DCNN with fundus images decreased the error rate to 4%. 相似文献
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A. Iranmanesh A. Kaveh 《International journal for numerical methods in engineering》1999,46(2):297-311
In this paper a neurocomputing strategy is presented which combines data processing capabilities of neural networks and numerical structural optimization. In this strategy, an improved counterpropagation neural network is used. Two artificial neural networks are trained, one for the constraints and the other for the gradients of the constraints and structural optimization is accomplished by using these nets. All required parameters such as weight matrices in the neural networks or the gradient computations are automated in this neuro‐optimizer strategy. Numerical examples are included to demonstrate the accuracy of the results. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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基于神经网络趋势分析 总被引:2,自引:2,他引:2
文章在分析研究了国内外现状的基础上 ,利用神经网络的非线性处理特性 ,提出了通过神经网络预测常见机械零件剩余寿命的方法 ,用实例验证了其有效性 相似文献
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本文在对目前学分制高校大学生学习水平测评方法进行分析的基础上,运用人工神经网络(ANN)理论中应用最为广泛的BP网络技术,构建了对大学生学习水平进行评价的非线性评价模型。实际模拟运算结果与现行的测评方法的结果基本近似,且有其独特的特点。与传统的统计分析模型相比具有更好的容错性、鲁棒性和自适应性。避免了人工确定各指标或各层次权重带来的主观性,使得不同科目的成绩具有一定的可比性。可为高校大学生各类学习标兵、奖学金、三好学生等的评比提供客观、可靠的依据。 相似文献
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综述了人工神经网络的发展历史及优缺点,阐述了人工神经网络模型的改进及在暖通空调负荷预测方面的应用,并展望了进一步的研究方向。 相似文献
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半导体封装测试系统等复杂制造系统的性能分析是项非常困难的任务。利用仿真模型构建两设备系统元模型,并以元模型为基石构建面向大规模复杂系统的近似解析方法是分析复杂制造系统的有效手段。为了快速准确地构建两设备系统元模型,提出了一种基于数据驱动仿真技术及人工神经网络的元模型构建方法。该方法以考虑缓存输送时间的两设备制造系统为研究对象,采用AREAN的二次开发技术实现仿真模型的自动配置、运行、统计,以生成人工神经网络所需案例,并通过比较分析BP、RBF和Chebyshev这3类典型的函数逼近神经网络确定最优的人工神经网络模型。实验结果表明径向基函数密度为120的RBF神经网络模型表现最优,其结果误差最小,能够成为大规模复杂制造系统近似解析方法的基石。 相似文献
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采用了一种改进的BP神经网络,针对BP神经网络的不足进行了改进:采用变学习率法减少网络训练时间、采用高斯惩罚函数避免局部最小值,并使整个网络能自主调整其隐层节点的数量.运用改进的BP神经网络对于样本进行训练,训练后的神经网络能够较为精确的预测SMT产品质量问题. 相似文献
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针对单个人工神经网络稳定性差、分类精度不高的缺点,提出了基于样本过滤的人工神经网络集成算法,并用于基因表达数据分类.采用基因表达数据集Leukemia进行实验仿真,并与单个BP神经网络、Bagging神经网络集成和支持向量机进行比较.结果表明,样本过滤算法具有更好的稳定性和更高的分类精度. 相似文献
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基于智能元件和神经网络的复合材料损伤监测 总被引:2,自引:0,他引:2
介绍了基于智能元件和人工神经网络技术对复合材料损伤监测的原理,回顾了人工神经网络在复合材料健康监测中的应用,总结了国内外的主要成果,提出了现在所存在的问题,并对应用神经网络进行复合材料的健康监测技术进行了展望。 相似文献
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为了将不同特质的人员安置到各自合适的工作岗位上去,人工神经网络中的约束满意模型被用来解决这个问题。该模型中的每一个结点都代表一个假设,各结点间的联结权重代表了各个假设之间的约束,同时,对于每一个结点都可以有来自外界的输入,必要时还可以为网络设置一定的偏置值。模拟实验的结果表明该模型经运行后可以找到最大程度地满足各种约束的人员安置方案。 相似文献
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结构拟动力试验中,误差累积是影响试验成功的主要因素之一,本文针对其中的设备误差采用人工神经网络的方法在试验的每一步进行检出修正,取得效果。 相似文献