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基于三维分类网络的前列腺辅助诊断 被引量:2
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作者 苏庆华 张姗姗 +6 位作者 蔡磊 谷焓 李奕飞 俞戈昊 江方舟 白翰林 赵地 《中国数字医学》 2019年第3期18-21,共4页
现代医学对数据可视化、科学化的分析需求增加,也增加了对医学影像的依赖性。但对于计算机而言,生物图像极为抽象,生物图像识别至今仍处于探索阶段,同时,对大、复杂三维医学图像特征提取和图像识别难度大。目前采用卷积神经网络对三维... 现代医学对数据可视化、科学化的分析需求增加,也增加了对医学影像的依赖性。但对于计算机而言,生物图像极为抽象,生物图像识别至今仍处于探索阶段,同时,对大、复杂三维医学图像特征提取和图像识别难度大。目前采用卷积神经网络对三维医学图像进行训练处理,由于训练数据集数量不足,经常出现过拟合现象。针对这些问题,基于TensorFlow深度学习框架,提出了一种新的前列腺辅助诊断模型。模型优化了深度学习网络层次,采用较少的参数加快训练速度,还能降低过拟合的可能性,此外还利用两种数据扩展方式进行数据扩充,并采用了dropout方法以避免过拟合。训练及测试结果表明,模型能够对大部分前列腺三维图像进行分类,判断出图像是否存在异常,正确率超过70%,优于同种条件下训练出的3DAlexNet网络图片分类模型。 展开更多
关键词 卷积神经网络 三维数据集 图片识别 数据扩充 过拟合
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Transparent open-box learning network and artificial neural network predictions of bubble-point pressure compared
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作者 David A.Wood Abouzar Choubineh 《Petroleum》 CSCD 2020年第4期375-384,共10页
The transparent open box(TOB)learning network algorithm offers an alternative approach to the lack of transparency provided by most machine-learning algorithms.It provides the exact calculations and relationships amon... The transparent open box(TOB)learning network algorithm offers an alternative approach to the lack of transparency provided by most machine-learning algorithms.It provides the exact calculations and relationships among the underlying input variables of the datasets to which it is applied.It also has the capability to achieve credible and auditable levels of prediction accuracy to complex,non-linear datasets,typical of those encountered in the oil and gas sector,highlighting the potential for underfitting and overfitting.The algorithm is applied here to predict bubble-point pressure from a published PVT dataset of 166 data records involving four easy-tomeasure variables(reservoir temperature,gas-oil ratio,oil gravity,gas density relative to air)with uneven,and in parts,sparse data coverage.The TOB network demonstrates high-prediction accuracy for this complex system,although it predictions applied to the full dataset are outperformed by an artificial neural network(ANN).However,the performance of the TOB algorithm reveals the risk of overfitting in the sparse areas of the dataset and achieves a prediction performance that matches the ANN algorithm where the underlying data population is adequate.The high levels of transparency and its inhibitions to overfitting enable the TOB learning network to provide complementary information about the underlying dataset to that provided by traditional machine learning algorithms.This makes them suitable for application in parallel with neural-network algorithms,to overcome their black-box tendencies,and for benchmarking the prediction performance of other machine learning algorithms. 展开更多
关键词 Learning network transparency Learning network performance compared Prediction of oil bubble point pressure Over fitting data sets for prediction Auditing machine learning predictions TOB complements ANN
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