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岩石节理力学参数的非线性估计 被引量:20
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作者 冯夏庭 王泳嘉 《岩土工程学报》 EI CAS CSCD 北大核心 1999年第3期268-272,共5页
通过建立一个多层神经网络模型NN(n,h1,h2,1),探讨了描述节理开度与剪切位移之间的非线性关系和尺度效应的新方法,由小尺度试件节理的实测数据建立的非线性模型可以推广地预测出较大一些尺度试件的节理开度值。对37条... 通过建立一个多层神经网络模型NN(n,h1,h2,1),探讨了描述节理开度与剪切位移之间的非线性关系和尺度效应的新方法,由小尺度试件节理的实测数据建立的非线性模型可以推广地预测出较大一些尺度试件的节理开度值。对37条现场实测的节理进行了分形特征研究,建立了分形维数与JRC关系式。 展开更多
关键词 岩石节理 开度 分形维数 剪切位移 非线性
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基于PCA-改进BP算法的软测量技术 被引量:12
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作者 臧春华 郭小萍 王秀丽 《仪表技术与传感器》 CSCD 北大核心 2001年第2期26-29,共4页
文中针对基本BP网络建立软测量模型时所存在的一些问题 ,例如 :输入变量之间可能存在的线性相关等冗余性、基本BP算法收敛速度较慢而且易于限于局部最优等 ,本文尝试将主元分析与变尺度改进BP算法相结合 ,以提高软测量模型的训练速度和... 文中针对基本BP网络建立软测量模型时所存在的一些问题 ,例如 :输入变量之间可能存在的线性相关等冗余性、基本BP算法收敛速度较慢而且易于限于局部最优等 ,本文尝试将主元分析与变尺度改进BP算法相结合 ,以提高软测量模型的训练速度和外推能力 ,为软测量技术的在线应用提供更大的方便。实验结果表明PCA方法与变尺度的改进BP神经元网络相结合的软测量建模方法在训练速度和外推能力方面有较大的改善。 展开更多
关键词 神经元网络 软测量技术 主元分析 变尺度
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基于改进YOLOv3的目标识别方法 被引量:20
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作者 陈正斌 叶东毅 +1 位作者 朱彩霞 廖建坤 《计算机系统应用》 2020年第1期49-58,共10页
在复杂的自然场景中,目标识别存在背景干扰、周围物体遮挡和光照变化等问题,同时识别的目标大多拥有多种不同的尺寸和类型.针对上述目标识别存在的问题,本文提出了一种基于改进YOLOv3的非限制自然场景中中等或较大尺寸的目标识别方法 (... 在复杂的自然场景中,目标识别存在背景干扰、周围物体遮挡和光照变化等问题,同时识别的目标大多拥有多种不同的尺寸和类型.针对上述目标识别存在的问题,本文提出了一种基于改进YOLOv3的非限制自然场景中中等或较大尺寸的目标识别方法 (简称CDSP-YOLO).该方法采用CLAHE图像增强预处理方法来消除自然场景中光照变化对目标识别效果的影响,并使用随机空间采样池化(S3Pool)作为特征提取网络的下采样方法来保留特征图的空间信息解决复杂环境中的背景干扰问题,而且对多尺度识别进行改进来解决YOLOv3对于中等或较大尺寸目标识别效果不佳的问题.实验结果表明:本文提出的方法在移动通信铁塔测试集上的准确率达97%,召回率达80%.与YOLOv3相比,该方法在非限制自然场景中的目标识别应用上具有更好的性能和推广应用前景. 展开更多
关键词 神经网络 深度学习 目标识别 YOLOv3 多尺度
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Melt Index Prediction by Neural Soft-Sensor Based on Multi-Scale Analysis and Principal Component Analysis 被引量:11
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作者 施健 刘兴高 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第6期849-852,共4页
Prediction of melt index (MI), the most important parameter in determining the product's grade and quality control of polypropylene produced in practical industrial processes, is studied. A novel soft-sensor model ... Prediction of melt index (MI), the most important parameter in determining the product's grade and quality control of polypropylene produced in practical industrial processes, is studied. A novel soft-sensor model with principal component analysis (PCA), radial basis function (RBF) networks, and multi-scale analysis (MSA) is proposed to infer the MI of manufactured products from real process variables, where PCA is carried out to select the most relevant process features and to eliminate the correlations of the input variables, MSA is introduced to a^quire much more information and to reduce the uncertainty of the system, and RBF networks are used to characterize the nonlinearity of the process. The research results show that the proposed method provides promising prediction reliability and accuracy, and supposed to have extensive application prospects in propylene polymerization processes. 展开更多
关键词 propylene polymerization neural soft-sensor principal component analysis multi-scale analysis
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一种MEMS陀螺标度因数误差补偿方法 被引量:11
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作者 房建成 张霄 李建利 《航空学报》 EI CAS CSCD 北大核心 2010年第2期350-355,共6页
高动态、恶劣温度环境下,微小型飞行器(MAV)导航、制导与控制系统关键器件微机电系统(MEMS)陀螺受温度和转速耦合影响,其标度因数误差呈强非线性特点,常规方法无法精确补偿。通过分析MEMS陀螺标度因数误差的产生机理,建立了包含温度和... 高动态、恶劣温度环境下,微小型飞行器(MAV)导航、制导与控制系统关键器件微机电系统(MEMS)陀螺受温度和转速耦合影响,其标度因数误差呈强非线性特点,常规方法无法精确补偿。通过分析MEMS陀螺标度因数误差的产生机理,建立了包含温度和转速非线性因素的标度因数误差模型,提出一种基于径向基(RBF)神经网络的标度因数非线性耦合误差补偿方法,解决了常规补偿方法精度差的问题。标定与补偿实验表明:在-10~+55℃温度范围、-150~+150(°)/s输入转速范围内,采用新方法补偿后MEMS陀螺输出平均精度比多项式拟合方法提高7倍;在-20~+20(°)/s低输入转速的误差强非线性区间内,精度提高近20倍,验证了本文方法的有效性和优越性。 展开更多
关键词 仪器仪表 误差补偿 神经网络 标度因数 微机电系统 微小型飞行器
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利用神经网络改进鸡疾病临床诊断专家系统 被引量:7
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作者 陆昌华 胡肄农 +2 位作者 陆庆文 王立方 王启明 《江苏农业学报》 CSCD 北大核心 1999年第1期42-46,共5页
探讨利用人工神经网络改进“鸡常见疾病临床诊断专家系统ESCCD”。BP训练算法可解决专家系统构造中的瓶颈问题——知识获取,但存在收敛性和泛化能力较差的缺陷。作者使用比例训练的BP算法,提出对训练模式进行样本重组的方法... 探讨利用人工神经网络改进“鸡常见疾病临床诊断专家系统ESCCD”。BP训练算法可解决专家系统构造中的瓶颈问题——知识获取,但存在收敛性和泛化能力较差的缺陷。作者使用比例训练的BP算法,提出对训练模式进行样本重组的方法,其特点是训练速度快、特征抽取能力强。结果表明,改进后的系统优于常规BP算法:系统可从病历中学习规则,诊断符合率从80%提高到94.1%,训练次数从7900次(常规BP算法)减少到800次,从而为探讨实现专家系统和神经网络的综合集成奠定基础,对构造类似专家系统具有普遍的适用意义。 展开更多
关键词 神经网络 鸡病 诊断 专家系统 比例训练
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十宣穴放血对急性脑梗死患者神经功能的影响 被引量:9
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作者 于川 申斌 《上海针灸杂志》 2014年第2期111-112,共2页
目的评价十宣放血对于急性脑梗死患者神经功能的影响。方法将92例急性期脑梗死患者随机分为观察组(46例)和对照组(46例)。对照组采用常规抗聚、改善循环治疗,观察组在对照组治疗基础上加十宣放血。以神经功能缺损程度NIHSS评分为指标,... 目的评价十宣放血对于急性脑梗死患者神经功能的影响。方法将92例急性期脑梗死患者随机分为观察组(46例)和对照组(46例)。对照组采用常规抗聚、改善循环治疗,观察组在对照组治疗基础上加十宣放血。以神经功能缺损程度NIHSS评分为指标,观察两种治疗方法的临床疗效差异。结果两组治疗后神经功能缺损评分比较差异有统计学意义(P<0.05)。两组有效率比较差异有统计学意义(P<0.01)。结论十宣放血对急性期脑梗死神经功能的恢复有着较好的疗效,提高了急性脑梗死的治疗有效率。 展开更多
关键词 十宣 刺血疗法 脑梗死 NIHSS评分
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基于改进BP神经元网络的软测量技术 被引量:5
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作者 王秀丽 臧春华 《沈阳化工》 2000年第4期230-232,245,共4页
针对基本BP神经元网络建立软测量模型所存在的几个问题:例如基本BP算法收敛速度较慢而且泛化能力较低等。本文尝试提出了变尺度与变步长相结合的改进BP神经网络软测量建模方法,以提高软测量模型的训练速度和外推能力,为软测量... 针对基本BP神经元网络建立软测量模型所存在的几个问题:例如基本BP算法收敛速度较慢而且泛化能力较低等。本文尝试提出了变尺度与变步长相结合的改进BP神经网络软测量建模方法,以提高软测量模型的训练速度和外推能力,为软测量技术的在线应用提供更大的方便。实验结果表明:该改进BP神经元网络软测量建模方法在训练速度和外推能力方面有较大改善。 展开更多
关键词 神经元网络 软测量技术 变尺度 变步长
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Evolutionary Neural Architecture Search and Its Applications in Healthcare 被引量:1
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作者 Xin Liu Jie Li +3 位作者 Jianwei Zhao Bin Cao Rongge Yan Zhihan Lyu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期143-185,共43页
Most of the neural network architectures are based on human experience,which requires a long and tedious trial-and-error process.Neural architecture search(NAS)attempts to detect effective architectures without human ... Most of the neural network architectures are based on human experience,which requires a long and tedious trial-and-error process.Neural architecture search(NAS)attempts to detect effective architectures without human intervention.Evolutionary algorithms(EAs)for NAS can find better solutions than human-designed architectures by exploring a large search space for possible architectures.Using multiobjective EAs for NAS,optimal neural architectures that meet various performance criteria can be explored and discovered efficiently.Furthermore,hardware-accelerated NAS methods can improve the efficiency of the NAS.While existing reviews have mainly focused on different strategies to complete NAS,a few studies have explored the use of EAs for NAS.In this paper,we summarize and explore the use of EAs for NAS,as well as large-scale multiobjective optimization strategies and hardware-accelerated NAS methods.NAS performs well in healthcare applications,such as medical image analysis,classification of disease diagnosis,and health monitoring.EAs for NAS can automate the search process and optimize multiple objectives simultaneously in a given healthcare task.Deep neural network has been successfully used in healthcare,but it lacks interpretability.Medical data is highly sensitive,and privacy leaks are frequently reported in the healthcare industry.To solve these problems,in healthcare,we propose an interpretable neuroevolution framework based on federated learning to address search efficiency and privacy protection.Moreover,we also point out future research directions for evolutionary NAS.Overall,for researchers who want to use EAs to optimize NNs in healthcare,we analyze the advantages and disadvantages of doing so to provide detailed guidance,and propose an interpretable privacy-preserving framework for healthcare applications. 展开更多
关键词 neural architecture search evolutionary computation large-scale multiobjective optimization distributed parallelism healthcare
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A deep neural network based surrogate model for damage identification in full-scale structures with incomplete noisy measurements
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作者 Tram BUI-NGOC Duy-Khuong LY +2 位作者 Tam T TRUONG Chanachai THONGCHOM T.NGUYEN-THOI 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2024年第3期393-410,共18页
The paper introduces a novel approach for detecting structural damage in full-scale structures using surrogate models generated from incomplete modal data and deep neural networks(DNNs).A significant challenge in this... The paper introduces a novel approach for detecting structural damage in full-scale structures using surrogate models generated from incomplete modal data and deep neural networks(DNNs).A significant challenge in this field is the limited availability of measurement data for full-scale structures,which is addressed in this paper by generating data sets using a reduced finite element(FE)model constructed by SAP2000 software and the MATLAB programming loop.The surrogate models are trained using response data obtained from the monitored structure through a limited number of measurement devices.The proposed approach involves training a single surrogate model that can quickly predict the location and severity of damage for all potential scenarios.To achieve the most generalized surrogate model,the study explores different types of layers and hyperparameters of the training algorithm and employs state-of-the-art techniques to avoid overfitting and to accelerate the training process.The approach’s effectiveness,efficiency,and applicability are demonstrated by two numerical examples.The study also verifies the robustness of the proposed approach on data sets with sparse and noisy measured data.Overall,the proposed approach is a promising alternative to traditional approaches that rely on FE model updating and optimization algorithms,which can be computationally intensive.This approach also shows potential for broader applications in structural damage detection. 展开更多
关键词 vibration-based damage detection deep neural network full-scale structures finite element model updating noisy incomplete modal data
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Multi-scale physics-informed neural networks for solving high Reynolds number boundary layer flows based on matched asymptotic expansions
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作者 Jianlin Huang Rundi Qiu +1 位作者 Jingzhu Wang Yiwei Wang 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2024年第2期76-81,共6页
Multi-scale system remains a classical scientific problem in fluid dynamics,biology,etc.In the present study,a scheme of multi-scale Physics-informed neural networks is proposed to solve the boundary layer flow at hig... Multi-scale system remains a classical scientific problem in fluid dynamics,biology,etc.In the present study,a scheme of multi-scale Physics-informed neural networks is proposed to solve the boundary layer flow at high Reynolds numbers without any data.The flow is divided into several regions with different scales based on Prandtl's boundary theory.Different regions are solved with governing equations in different scales.The method of matched asymptotic expansions is used to make the flow field continuously.A flow on a semi infinite flat plate at a high Reynolds number is considered a multi-scale problem because the boundary layer scale is much smaller than the outer flow scale.The results are compared with the reference numerical solutions,which show that the msPINNs can solve the multi-scale problem of the boundary layer in high Reynolds number flows.This scheme can be developed for more multi-scale problems in the future. 展开更多
关键词 Physics-informed neural networks(PINNs) MULTI-scale Fluid dynamics Boundary layer
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A sub-grid scale model for Burgers turbulence based on the artificial neural network method
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作者 Xin Zhao Kaiyi Yin 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2024年第3期162-165,共4页
The present study proposes a sub-grid scale model for the one-dimensional Burgers turbulence based on the neuralnetwork and deep learning method.The filtered data of the direct numerical simulation is used to establis... The present study proposes a sub-grid scale model for the one-dimensional Burgers turbulence based on the neuralnetwork and deep learning method.The filtered data of the direct numerical simulation is used to establish thetraining data set,the validation data set,and the test data set.The artificial neural network(ANN)methodand Back Propagation method are employed to train parameters in the ANN.The developed ANN is applied toconstruct the sub-grid scale model for the large eddy simulation of the Burgers turbulence in the one-dimensionalspace.The proposed model well predicts the time correlation and the space correlation of the Burgers turbulence. 展开更多
关键词 Artificial neural network Back propagation method Burgers turbulence Large eddy simulation Sub-grid scale model
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Gait and Glasgow Coma Scale scores can predict functional recovery in patients with traumatic brain injury 被引量:3
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作者 Sevil Bilgin Arzu Guclu-Gunduz +2 位作者 Hakan Oruckaptan Nezire Kose Bülent Celik 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第25期1978-1984,共7页
Fifty-one patients with mild (n -- 14), moderate (n = 10) and severe traumatic brain injury (n = 27) received early rehabilitation. Level of consciousness was evaluated using the Glasgow Coma Score Functional le... Fifty-one patients with mild (n -- 14), moderate (n = 10) and severe traumatic brain injury (n = 27) received early rehabilitation. Level of consciousness was evaluated using the Glasgow Coma Score Functional level was determined using the Glasgow Outcome Score, whilst mobility was evaluated using the Mobility Scale for Acute Stroke. Activities of daily living were assessed using the Barthel Index. Following Bobath neurodevelopmental therapy, the level of consciousness was significantly improved in patients with moderate and severe traumatic brain injury, but was not greatly influenced in patients with mild traumatic brain injury. Mobility and functional level were significantly improved in patients with mild, moderate and severe traumatic brain injury. Gait recovery was more obvious in patients with mild traumatic brain injury than in patients with moderate and severe traumatic brain injury. Activities of daily living showed an improvement but this was insignificant except for patients with severe traumatic brain injury. Nevertheless, complete recovery was not acquired at discharge. Multiple regression analysis showed that gait and Glasgow Coma Scale scores can be considered predictors of functional outcomes following traumatic brain injury. 展开更多
关键词 brain injury traumatic brain injury REHABILITATION early rehabilitation function PROGNOSIS GlasgowComa scale Glasgow Outcome scale functional level neural regeneration
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基于Hopfield神经网络求解较大规模TSP的新方法 被引量:5
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作者 石红国 饶煜 郭寒英 《综合运输》 2018年第10期77-82,共6页
利用Hopfield神经网络求解超过100个城市的旅行商问题(TSP)时,由于Hopfield神经网络能量函数局部极小点太多导致求解困难,本文提出一种Hopfield神经网络与归约方法相结合求解较大规模TSP问题的通用方法,通过提取原TSP问题较优解之... 利用Hopfield神经网络求解超过100个城市的旅行商问题(TSP)时,由于Hopfield神经网络能量函数局部极小点太多导致求解困难,本文提出一种Hopfield神经网络与归约方法相结合求解较大规模TSP问题的通用方法,通过提取原TSP问题较优解之间的公共边,降低城市规模并构造一个新的TSP问题,再利用Hopfield神经网络求解新TSP问题并在得到较优解后将之还原,以此获得原TSP问题的较优解。计算机仿真表明该方法可以快速获得较大规模TSP问题较优解,提高了使用Hopfield神经网络求解TSP问题的适用城市规模。 展开更多
关键词 神经网络 旅行商问题 较大规模 公共边 归约
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基于神经网络模型的室内大规模人流密度预测 被引量:5
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作者 宋宇波 彭朝阳 +3 位作者 苏悦 刘蕴箫 赵千锋 朱珍超 《北京理工大学学报》 EI CAS CSCD 北大核心 2019年第7期714-718,770,共6页
提出了一种新型的适用于大规模室内人流密度预测算法.在现有基于无线信号强度的人流密度估算算法基础上,引入加权运算来提升估算质量.进一步,根据连续若干个时间段内估算所得的人流密度,通过BP神经网络模型,对未来某一时刻该区域的人流... 提出了一种新型的适用于大规模室内人流密度预测算法.在现有基于无线信号强度的人流密度估算算法基础上,引入加权运算来提升估算质量.进一步,根据连续若干个时间段内估算所得的人流密度,通过BP神经网络模型,对未来某一时刻该区域的人流密度进行预测.根据仿真模型和3个月的数据采集与分析,所得到预测模型的准确率达到了94.70%. 展开更多
关键词 人流密度 神经网络 大规模 室内
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非痴呆型血管性认知功能障碍合并脑微出血患者磁敏感加权成像检查与神经量表的相关性 被引量:4
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作者 李琳 孙冬萌 《国际老年医学杂志》 2022年第1期26-30,共5页
目的探讨基于磁敏感加权成像(SWAN)检查中老年非痴呆型血管性认知功能障碍(VCIND)合并脑微出血(CMBs)与神经量表的相关性。方法选择2017年2月~2019年8月中国人民解放军北部战区总医院收治的CMBs患者350例,根据是否发生VCIND将患者分为VC... 目的探讨基于磁敏感加权成像(SWAN)检查中老年非痴呆型血管性认知功能障碍(VCIND)合并脑微出血(CMBs)与神经量表的相关性。方法选择2017年2月~2019年8月中国人民解放军北部战区总医院收治的CMBs患者350例,根据是否发生VCIND将患者分为VCIND组(46例)和对照组(304例);根据CMBs数量评估病情严重程度分为轻度组105例、中度组167例、重度组78例;根据CMBs部位分为皮质-皮质下组(126例)、基底节-丘脑组(101例)、脑干组(74例)、小脑组(49例)。所有患者均行SWAN扫描明确CMBs部位和个数,并行蒙特利尔认知评估(MoCA)、简易智能精神状态检查(MMSE)、临床痴呆评定(CDR)、美国国立卫生院神经功能缺损评分(NIHSS)量表评估认知功能和神经功能缺损程度。观察不同CMBs部位、CMBs病情程度,患者MoCA、MMSE、CDR、NIHSS评分差异,采用logistic回归分析CMBs与认知功能障碍的相关性。结果VCIND组MoCA、MMSE评分低于对照组(P<0.05),CDR、NIHSS评分高于对照组(P<0.05),皮质-皮质下组MoCA、MMSE评分低于基底节-丘脑组、脑干组、小脑组(P<0.05),CDR评分高于基底节-丘脑组、脑干组、小脑组(P<0.05)。MoCA、MMSE评分随着CMBs病情加重而降低(P<0.05),CDR、NIHSS评分随着CMBs病情加重而升高(P<0.05)。logistic回归分析结果显示白质疏松、皮质-皮质下CMBs、重度CMBs是CMBs患者发生VCIND的独立危险因素(P<0.01)。结论缺血性脑卒中后继发CMBs患者易发生VCIND,CMBs部位以及多发CMBs病灶患者认知功能受损更明显。 展开更多
关键词 非痴呆型血管性认知功能障碍 脑微出血 磁敏感加权成像 神经量表
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基于2阶段循环神经网络的语音增强算法 被引量:1
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作者 章琳志 刘梦强 +1 位作者 张夜 张燕凯 《网络新媒体技术》 2023年第5期45-50,共6页
基于神经网络的语音增强算法模型直接在时域或时频域操作导致算法具有很高的复杂度,难以在低算力平台下实现应用。针对这一问题,提出一种基于2阶段循环神经网络的语音增强算法,在保证算法性能的前提下,大幅减少了算法复杂度。算法由2阶... 基于神经网络的语音增强算法模型直接在时域或时频域操作导致算法具有很高的复杂度,难以在低算力平台下实现应用。针对这一问题,提出一种基于2阶段循环神经网络的语音增强算法,在保证算法性能的前提下,大幅减少了算法复杂度。算法由2阶段子网络构成,第一阶段对语音的梅尔子带特征利用循环神经网络进行建模预测幅度谱掩码以实现语音幅度的增强。第2阶段通过循环神经网络估计噪声幅值联合相位谱补偿算法实现语音的相位的补偿。通过2阶段网络并行优化,获得了较好的增强性能。实验结果表明:相比基线模型,本文提出的算法在更低的复杂度情况下,在语音的客观指标上依旧具有优良的表现。 展开更多
关键词 语音增强 神经网络 梅尔尺度 相位谱补偿 模型复杂度
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Lightweight Image Super-Resolution via Weighted Multi-Scale Residual Network 被引量:5
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作者 Long Sun Zhenbing Liu +3 位作者 Xiyan Sun Licheng Liu Rushi Lan Xiaonan Luo 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第7期1271-1280,共10页
The tradeoff between efficiency and model size of the convolutional neural network(CNN)is an essential issue for applications of CNN-based algorithms to diverse real-world tasks.Although deep learning-based methods ha... The tradeoff between efficiency and model size of the convolutional neural network(CNN)is an essential issue for applications of CNN-based algorithms to diverse real-world tasks.Although deep learning-based methods have achieved significant improvements in image super-resolution(SR),current CNNbased techniques mainly contain massive parameters and a high computational complexity,limiting their practical applications.In this paper,we present a fast and lightweight framework,named weighted multi-scale residual network(WMRN),for a better tradeoff between SR performance and computational efficiency.With the modified residual structure,depthwise separable convolutions(DS Convs)are employed to improve convolutional operations’efficiency.Furthermore,several weighted multi-scale residual blocks(WMRBs)are stacked to enhance the multi-scale representation capability.In the reconstruction subnetwork,a group of Conv layers are introduced to filter feature maps to reconstruct the final high-quality image.Extensive experiments were conducted to evaluate the proposed model,and the comparative results with several state-of-the-art algorithms demonstrate the effectiveness of WMRN. 展开更多
关键词 Convolutional neural network(CNN) lightweight framework MULTI-scale SUPER-RESOLUTION
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Pulsed arterial spin labeling effectively and dynamically observes changes in cerebral blood flow after mild traumatic brain injury 被引量:3
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作者 Shu-ping Peng Yi-ning Li +5 位作者 Jun Liu Zhi-yuan Wang Zi-shu Zhang Shun-ke Zhou Fang-xu Tao Zhi-xue Zhang 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第2期257-261,共5页
Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury... Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient's condition and judging prognosis after traumatic brain injury. 展开更多
关键词 nerve regeneration MRI pulsed arterial spin labeling technique cerebral blood flow mild traumatic brain injury GlasgowComa scale white matter gray matter CT neural regeneration
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多尺度膨胀卷积在图像分类中的应用 被引量:4
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作者 吴昊昊 王方石 《计算机科学》 CSCD 北大核心 2020年第S01期166-171,186,共7页
在采用深度学习进行图像分类时,为减少下采样导致的空间信息损失,往往采用膨胀卷积代替下采样,但尚未有文献研究膨胀卷积作用于不同网络层的性能差异。文中进行了大量图像分类实验,找到了适宜膨胀卷积作用的最佳网络层。但使用膨胀卷积... 在采用深度学习进行图像分类时,为减少下采样导致的空间信息损失,往往采用膨胀卷积代替下采样,但尚未有文献研究膨胀卷积作用于不同网络层的性能差异。文中进行了大量图像分类实验,找到了适宜膨胀卷积作用的最佳网络层。但使用膨胀卷积会丢失近邻点的相关信息,导致网格现象,造成图像部分局部信息的丢失。为消除网格现象,又提出在前述最佳网络层采用多尺度膨胀卷积构建神经网络的方法。实验结果表明,所提出的构建网络方法在图像分类中取得了较好的效果。 展开更多
关键词 神经网络 图像分类 膨胀卷积 多尺度
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