期刊文献+
共找到1,681篇文章
< 1 2 85 >
每页显示 20 50 100
A Single Image Derain Method Based on Residue Channel Decomposition in Edge Computing
1
作者 Yong Cheng Zexuan Yang +3 位作者 Wenjie Zhang Ling Yang Jun Wang Tingzhao Guan 《Intelligent Automation & Soft Computing》 SCIE 2023年第8期1469-1482,共14页
The numerous photos captured by low-price Internet of Things(IoT)sensors are frequently affected by meteorological factors,especially rainfall.It causes varying sizes of white streaks on the image,destroying the image... The numerous photos captured by low-price Internet of Things(IoT)sensors are frequently affected by meteorological factors,especially rainfall.It causes varying sizes of white streaks on the image,destroying the image texture and ruining the performance of the outdoor computer vision system.Existing methods utilise training with pairs of images,which is difficult to cover all scenes and leads to domain gaps.In addition,the network structures adopt deep learning to map rain images to rain-free images,failing to use prior knowledge effectively.To solve these problems,we introduce a single image derain model in edge computing that combines prior knowledge of rain patterns with the learning capability of the neural network.Specifically,the algorithm first uses Residue Channel Prior to filter out the rainfall textural features then it uses the Feature Fusion Module to fuse the original image with the background feature information.This results in a pre-processed image which is fed into Half Instance Net(HINet)to recover a high-quality rain-free image with a clear and accurate structure,and the model does not rely on any rainfall assumptions.Experimental results on synthetic and real-world datasets show that the average peak signal-to-noise ratio of the model decreases by 0.37 dB on the synthetic dataset and increases by 0.43 dB on the real-world dataset,demonstrating that a combined model reduces the gap between synthetic data and natural rain scenes,improves the generalization ability of the derain network,and alleviates the overfitting problem. 展开更多
关键词 single image derain method edge computing residue channel prior feature fusion module
下载PDF
Single channel signal component separation using Bayesian estimation 被引量:4
2
作者 Cai Quanwei Wei Ping Xiao Xianci 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第1期33-39,共7页
A Bayesian estimation method to separate multicomponent signals with single channel observation is presented in this paper. By using the basis function projection, the component separation becomes a problem of limited... A Bayesian estimation method to separate multicomponent signals with single channel observation is presented in this paper. By using the basis function projection, the component separation becomes a problem of limited parameter estimation. Then, a Bayesian model for estimating parameters is set up. The reversible jump MCMC (Monte Carlo Markov Chain) algorithmis adopted to perform the Bayesian computation. The method can jointly estimate the parameters of each component and the component number. Simulation results demonstrate that the method has low SNR threshold and better performance. 展开更多
关键词 Signal component separation single channel Bayesian estimation Reversible jump MCMC
下载PDF
Single channel source separation of radar fuze mixed signal based on phase difference analysis 被引量:2
3
作者 Hang ZHU Shu-ning ZHANG Hui-chang ZHAO 《Defence Technology(防务技术)》 SCIE EI CAS 2014年第3期308-315,共8页
A new method based on phase difference analysis is proposed for the single-channel mixed signal separation of single-channel radar fuze.This method is used to estimate the mixing coefficients of de-noised signals thro... A new method based on phase difference analysis is proposed for the single-channel mixed signal separation of single-channel radar fuze.This method is used to estimate the mixing coefficients of de-noised signals through the cumulants of mixed signals,solve the candidate data set by the mixing coefficients and signal analytical form,and resolve the problem of vector ambiguity by analyzing the phase differences.The signal separation is realized by exchanging data of the solutions.The waveform similarity coefficients are calculated,and the time鈥攆requency distributions of separated signals are analyzed.The results show that the proposed method is effective. 展开更多
关键词 single channel source SEPARATION RADAR FUZE signal Phase DIFFERENCE analysis VECTOR AMBIGUITY
下载PDF
Single channel blind source separation based on ICA feature extraction 被引量:2
4
作者 孔薇 杨斌 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第4期518-523,共6页
A new technique is proposed to solve the blind source separation (BSS) given only a single channel observation. The basis functions and the density of the coefficients of source signals learned by ICA are used as the ... A new technique is proposed to solve the blind source separation (BSS) given only a single channel observation. The basis functions and the density of the coefficients of source signals learned by ICA are used as the prior knowledge. Based on the learned prior information the learning rules of single channel BSS are presented by maximizing the joint log likelihood of the mixed sources to obtain source signals from single observation, in which the posterior density of the given measurements is maximized. The experimental results exhibit a successful separation performance for mixtures of speech and music signals. 展开更多
关键词 blind source separation (BSS) independent component analysis (ICA) single channel maximum likelihood
下载PDF
Learning a discriminative high-fidelity dictionary for single channel source separation 被引量:1
5
作者 TIAN Yuanrong WANG Xing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第5期1097-1110,共14页
Sparse-representation-based single-channel source separation,which aims to recover each source’s signal using its corresponding sub-dictionary,has attracted many scholars’attention.The basic premise of this model is... Sparse-representation-based single-channel source separation,which aims to recover each source’s signal using its corresponding sub-dictionary,has attracted many scholars’attention.The basic premise of this model is that each sub-dictionary possesses discriminative information about its corresponding source,and this information can be used to recover almost every sample from that source.However,in a more general sense,the samples from a source are composed not only of discriminative information but also common information shared with other sources.This paper proposes learning a discriminative high-fidelity dictionary to improve the separation performance.The innovations are threefold.Firstly,an extra sub-dictionary was combined into a conventional union dictionary to ensure that the source-specific sub-dictionaries can capture only the purely discriminative information for their corresponding sources because the common information is collected in the additional sub-dictionary.Secondly,a task-driven learning algorithm is designed to optimize the new union dictionary and a set of weights that indicate how much of the common information should be allocated to each source.Thirdly,a source separation scheme based on the learned dictionary is presented.Experimental results on a human speech dataset yield evidence that our algorithm can achieve better separation performance than either state-of-the-art or traditional algorithms. 展开更多
关键词 single channel source separation sparse representation dictionary learning DISCRIMINATION high-fidelity
下载PDF
Magnesium permeation through mechanosensitive channels:single-current measurements
6
作者 Alexander V StanIschenko AnastasiyaVSudarikova +1 位作者 YuriANegulyaev ElenaAMorachevskaya 《Cell Research》 SCIE CAS CSCD 2006年第8期723-730,共8页
Compelling evidence shows that intracellular free magnesium [Mg^2+]i may be a critical regulator of cell activity in eukaryotes. However, membrane transport mechanisms mediating Mg^2+ influx in mammalian cells are p... Compelling evidence shows that intracellular free magnesium [Mg^2+]i may be a critical regulator of cell activity in eukaryotes. However, membrane transport mechanisms mediating Mg^2+ influx in mammalian cells are poorly understood. Here, we show that mechanosensitive (MS) cationic channels activated by stretch are permeable for Mg^2+ ions at different extracellular concentrations including physiological ones. Single-channel currents were recorded from cell-attached and inside-out patches on K562 leukaemia cells at various concentrations of MgCl2 when Mg^2+ was the only available carrier of inward currents. At 2 mM Mg^2+, inward mechanogated currents representing Mg^2+ influx through MS channels corresponded to the unitary conductance of about 5 pS. At higher Mg^2+ levels, only slight increase of single-channel currents and conductance occurred, implying that Mg^2+ permeation through MS channels is characterized by strong saturation. At 20 and 90 mM Mg^2+, mean conductance values for inward currents carried by Mg^2+ were rather similar, being equal to 6.8 ± 0.5 and 6.4 ± 0.5 pS, respectively. The estimation of the channel-selective permeability according to constant field equation is obviously limited due to saturation effects. We conclude that the detection of single currents is the main evidence for Mg^2+ permeation through membrane channels activated by stretch. Our single-current measurements document Mg^2+ influx through MS channels in the plasma membrane of leukaemia cells. 展开更多
关键词 MAGNESIUM single currents mechanosensitive channel human leukaemia cell
下载PDF
The Reconstructing of Low Signal-noise Ratio Single Ion Channel Signal from Patch-clamp Recordings Sampled in the Colored Background Noise
7
作者 韩晓东 LiuXiangming 《High Technology Letters》 EI CAS 2002年第3期72-77,共6页
The single ion channel signal is an ionic current that can be recorded by the patch clamp technique. Hidden Markov model (HMM) algorithm has been used to convert the low signal noise ratio (SNR) noisy recording into a... The single ion channel signal is an ionic current that can be recorded by the patch clamp technique. Hidden Markov model (HMM) algorithm has been used to convert the low signal noise ratio (SNR) noisy recording into an idealized quantal one in the case of white background noise. The traditional HMM algorithm is extended and adapted to the colored background noise. A new algorithm called EHMM (Extended HMM) algorithm is proposed, and mainly validated by simulation. Results show that it’s effective. 展开更多
关键词 single ion channel signal patch clamp technique single reconstructing hidden Markov model EM algorithm
下载PDF
The on-line direct fitting of low signal-noise ratio single ion channel recordings based on hidden Markov models
8
作者 HAN Xiao dong,LIU Xiang ming,PAN Hua,TAO min,LIN Jia rui Institute of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074,China 《Chinese Journal of Biomedical Engineering(English Edition)》 2002年第2期51-60,共10页
Many kinds of channel currents are especially weak and the background noise dominates in the patch clamp recordings. This makes the threshold detection fail during estimating of the transition probabilities. So direct... Many kinds of channel currents are especially weak and the background noise dominates in the patch clamp recordings. This makes the threshold detection fail during estimating of the transition probabilities. So direct fitting of the patch clamp recording, not of the histogram coming from the recordings, is a desirable way to estimate the transition probabilities. Iterative batch EM algorithm based on hidden markov model has been used in this field but which has the "curse of dimensionality" and besides cant keep tracking the varying of the parameters. A new on line sequential iterative one is proposed here, which needs fewer computational efforts and can adaptively keep tracking the varying of parameters. Simulations suggest its robust, effective and convenient. 展开更多
关键词 single ion channel RECORDING hidden MARKOV model (HMM) on line algorithm Kullback Leibler (KL) information measure
下载PDF
Single-Channel Speech Enhancement Using Critical-Band Rate Scale Based Improved Multi-Band Spectral Subtraction 被引量:1
9
作者 Navneet Upadhyay Abhijit Karmakar 《Journal of Signal and Information Processing》 2013年第3期314-326,共13页
This paper addresses the problem of single-channel speech enhancement in the adverse environment. The critical-band rate scale based on improved multi-band spectral subtraction is investigated in this study for enhanc... This paper addresses the problem of single-channel speech enhancement in the adverse environment. The critical-band rate scale based on improved multi-band spectral subtraction is investigated in this study for enhancement of single-channel speech. In this work, the whole speech spectrum is divided into different non-uniformly spaced frequency bands in accordance with the critical-band rate scale of the psycho-acoustic model and the spectral over-subtraction is carried-out separately in each band. In addition, for the estimation of the noise from each band, the adaptive noise estimation approach is used and does not require explicit speech silence detection. The noise is estimated and updated by adaptively smoothing the noisy signal power in each band. The smoothing parameter is controlled by a-posteriori signal-to-noise ratio (SNR). For the performance analysis of the proposed algorithm, the objective measures, such as, SNR, segmental SNR, and perceptual evaluations of the speech quality are conducted for the variety of noises at different levels of SNRs. The speech spectrogram and objective evaluations of the proposed algorithm are compared with other standard speech enhancement algorithms and proved that the musical structure of the remnant noise and background noise is better suppressed by the proposed algorithm. 展开更多
关键词 single-channel SPEECH Enhancement Critical-Band RATE SCALE Spectral Over-Subtraction Adaptive Noise Estimation Objective Measure SPEECH Spectrograms
下载PDF
Construction of Low Delay Maximal Rate Single-Symbol Decodable Distributed STBC with Channel Phase Information
10
作者 Chen Junsheng Zhang Xiaofei +1 位作者 Shu Feng Wang Jianxin 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2016年第6期-,共7页
Exploiting the source-to-relay channel phase information at the relays can increase the rate upper-bound of distributed orthogonal space-time block codes(STBC)from 2/K to 1/2,where Kis the number of relays.This techni... Exploiting the source-to-relay channel phase information at the relays can increase the rate upper-bound of distributed orthogonal space-time block codes(STBC)from 2/K to 1/2,where Kis the number of relays.This technique is known as distributed orthogonal space-time block codes with channel phase information(DOSTBC-CPI).However,the decoding delay of existing DOSTBC-CPIs is not optimal.Therefore,based on the rate of 1/2 balanced complex orthogonal design(COD),an algorithm is provided to construct a maximal rate DOSTBC-CPI with only half the decoding delay of existing DOSTBC-CPI.Simulation results show that the proposed method exhibits lower symbol error rate than the existing DOSTBC-CPIs. 展开更多
关键词 distributed STBC channel phase information decoding delay single-symbol decoding
下载PDF
Single-Channel Compressive Sensing for DOA Estimation via Sensing Model Optimization
11
作者 Hongtao Li Zeshi Yuan 《International Journal of Communications, Network and System Sciences》 2017年第5期191-201,共11页
The performance of multi-channel Compressive Sensing (CS)-based Direction-of-Arrival (DOA) estimation algorithm degrades when the gains between Radio Frequency (RF) channels are inconsistent, and when target angle inf... The performance of multi-channel Compressive Sensing (CS)-based Direction-of-Arrival (DOA) estimation algorithm degrades when the gains between Radio Frequency (RF) channels are inconsistent, and when target angle information mismatches with system sensing model. To solve these problems, a novel single-channel CS-based DOA estimation algorithm via sensing model optimization is proposed. Firstly, a DOA sparse sensing model using single-channel array considering the sensing model mismatch is established. Secondly, a new single-channel CS-based DOA estimation algorithm is presented. The basic idea behind the proposed algorithm is to iteratively solve two CS optimizations with respect to target angle information vector and sensing model quantization error vector, respectively. In addition, it avoids the loss of DOA estimation performance caused by the inconsistent gain between RF channels. Finally, simulation results are presented to verify the efficacy of the proposed algorithm. 展开更多
关键词 COMPRESSIVE SENSING DIRECTION-OF-ARRIVAL Estimation single-channel Mismatching ERROR
下载PDF
Fine Single Channel Identification Controlled by Sedimentary Facies—Taking KLA Oilfield as an Example
12
作者 Shaopeng Wang Pengfei Mu +2 位作者 Qiongyuan Wu Meijia Liu Xuefang Zhang 《Open Journal of Geology》 2022年第3期188-198,共11页
The Neogene fluvial reservoir in the Bohai oilfield is one of the leading development horizons for increasing reserves and production in the Bohai oilfield. However, the development of offshore fluvial reservoirs is f... The Neogene fluvial reservoir in the Bohai oilfield is one of the leading development horizons for increasing reserves and production in the Bohai oilfield. However, the development of offshore fluvial reservoirs is faced with the problems of thin reservoir thickness, narrow plane width, rapid lateral change, and thin well pattern. Taking the KLA oilfield as an example, this paper discusses the nuanced characterization and configuration of a single channel controlled by sedimentary facies to guide developing offshore river facies’ narrow channel main control oilfield. Firstly, based on a large number of core data, the acceptable sedimentary facies identification is realized, the sedimentary model of the study area is established, the delicate calibration of logging facies and seismic facies is realized under the constraint of the sedimentary model, and a set of technical methods for nuanced reservoir characterization guided by seismic sedimentology is summarized, to realize the boundary identification of composite channel configuration and further realize the nuanced characterization of the single narrow channel. Based on this set of technology, it guides the smooth implementation of horizontal wells in the oilfield. The drilling encounter rate of the reservoir in the horizontal section of the single well exceeds 90%, ensuring the injection production connectivity and increasing the reserve production rate by more than 10%. 展开更多
关键词 Sedimentary Facies Control single-channel Reservoir Characterization Cost Reduction Efficiency Increase
下载PDF
Deterministic joint remote state preparation of arbitrary single- and two-qubit states 被引量:1
13
作者 陈娜 权东晓 +2 位作者 徐馥芳 杨宏 裴昌幸 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第10期71-77,共7页
In this paper, two novel schemes for deterministic joint remote state preparation(JRSP) of arbitrary single- and twoqubit states are proposed. A set of ingenious four-particle partially entangled states are construc... In this paper, two novel schemes for deterministic joint remote state preparation(JRSP) of arbitrary single- and twoqubit states are proposed. A set of ingenious four-particle partially entangled states are constructed to serve as the quantum channels. In our schemes, two senders and one receiver are involved. Participants collaborate with each other and perform projective measurements on their own particles under an elaborate measurement basis. Based on their measurement results,the receiver can reestablish the target state by means of appropriate local unitary operations deterministically. Unit success probability can be achieved independent of the channel's entanglement degree. 展开更多
关键词 joint remote state preparation four-particle partially entangled quantum channel single-qubitstate two-qubit state
下载PDF
Single carrier frequency domain equalization and diversity combining for cooperative systems
14
作者 熊骇韬 Xu Jing Wang Ping 《High Technology Letters》 EI CAS 2009年第1期75-79,共5页
A low-complexity single carrier frequency-domain equalizer (SC/FDE) and diversity combining method for cooperative systems with demodulate-and-forward relaying over frequency-selective channels is proposed. At the r... A low-complexity single carrier frequency-domain equalizer (SC/FDE) and diversity combining method for cooperative systems with demodulate-and-forward relaying over frequency-selective channels is proposed. At the relay nodes, linear SC/FDE is adopted and normalized correlation coefficlent is mtrodueed to derive an equivalent source-to-relay-destination (S-R-D) channel that is highlighted in this study. At the destination, a joint SC/FDE and diversity combining receiver is proposed by utilizing the equivalent S-R-D channel. Simulation results demonstrate the superiority of the proposed SC/FDE scheme over the straightforward SC/FDE which ignores the decisions errors at the intermediate relay nodes. 展开更多
关键词 demodulate-and-forward single cartier frequency-domain equalization (SC/FDE) relay- channel cooperative diversity
下载PDF
Clinical Analysis of Minimally Invasive Single-segment Reduction and Internal Fixation in Patients with Thoracolumbar Fractures
15
作者 Sun Xiuchen 《Journal of Clinical and Nursing Research》 2018年第1期23-27,共5页
Objective:To study the clinical effect of minimally invasive single-segment reduction and internal fixation in patients with thoracolumbar fractures.Methods:From June 2013 to June 2014,100 patients with thoracolumbar ... Objective:To study the clinical effect of minimally invasive single-segment reduction and internal fixation in patients with thoracolumbar fractures.Methods:From June 2013 to June 2014,100 patients with thoracolumbar fractures were selected as the subjects and they were randomly divided into observation group(50 cases)and control group(50 cases).The patients in the observation group were treated with minimally invasive singlesegment reduction and internal fixation.The patients in the control group were treated with short segmental fixation.The clinical effects of the two groups were compared.Results:There was no significant difference in the compression rate and Cobb angle between the two groups before and after operation(P>0.05).For all patients who were followed up for the last time,the Cobb angle was significantly lower in the observation group than in the control group(P<0.05).The social function,affective function and physical pain score of the observation group were significantly better than the control group(P<0.05).The amount of bleeding in the observation group was(250.4±41.0)ml,which was significantly lower than that in the control group(267.5±32.8)ml.The time required for the operation was(90.2±35.4)min,which was significantly lower than that of the control group(104.5±22.6)min(P<0.05).After treatment,the prognosis was 70.00%and the excellent and good rate was 98.00%,which was significantly higher than that of the control group(46.00%)and 78.00%(P<0.05).Conclusion:Thoracolumbar fractures in patients with dilated channel minimally invasive single-segment reduction and internal fixation treatment can effectively repair the patient's vertebral height and Cobb angle and the degree of correction after surgery was significantly better,safer and worthy of clinical recommended use. 展开更多
关键词 THORACOLUMBAR FRACTURES DILATED channels MINIMALLY invasive single SEGMENT reduction Internal fixation
下载PDF
用于多通道单分子定位的高精度图像配准方法 被引量:1
16
作者 林丹樱 龚振权 +3 位作者 黄黎琳 聂梦娇 于斌 屈军乐 《物理学报》 SCIE EI CAS CSCD 北大核心 2024年第6期374-385,共12页
单分子定位技术可以绕过光学系统的衍射限制,在生物样品的单粒子追踪和超分辨显微成像中得到了广泛应用.多通道单分子定位采用多个成像通道,可以实现对不同目标的同时追踪或多色超分辨成像,也可以提升单粒子追踪的轴向深度或实现更高的... 单分子定位技术可以绕过光学系统的衍射限制,在生物样品的单粒子追踪和超分辨显微成像中得到了广泛应用.多通道单分子定位采用多个成像通道,可以实现对不同目标的同时追踪或多色超分辨成像,也可以提升单粒子追踪的轴向深度或实现更高的定位精度和密度.但各通道图像间的差异会影响协同定位或定量分析,因此图像配准是其图像数据预处理的关键环节;且由于单分子定位精度高,其对多通道图像配准精度的要求也很高.现有技术一般采用基于控制点的配准方法,且多采用复杂而精密的方式来获取基准物网格图像用于定位得到控制点对,以实现高精度图像配准,对样品或实验设备要求高,难以直接推广.为此,本文基于局部非线性变换和误匹配点剔除,发展了一种可以直接采用随机分布荧光珠样品作为基准物的高精度图像配准方法,通过在特征匹配和变换模型参数估计的过程中对控制点进行监测和迭代筛选,以剔除因单分子定位不准确或精度差而导致未精确匹配的控制点对,从而消除以随机分布荧光珠样品作为基准物时对于控制点准确获取和精确匹配所带来的不良影响,同时采用基于局部加权平均的二阶多项式拟合进行变换模型参数估计,以更好地适用于不同通道间存在局部非线性形变的情形.结果表明,采用该方法只需要3次迭代,就可以将未准确定位和精确匹配的控制点对找到并剔除,从而实现更准确的变换模型参数估计,将配准精度提高一个数量级,在图像局部非线性形变情况严重的正交像散双通道单分子定位成像系统中实现了约6 nm的配准精度. 展开更多
关键词 单分子定位 多通道成像 图像配准 误匹配点剔除
下载PDF
基于双分支注意力U-Net的语音增强方法 被引量:1
17
作者 曹洁 王宸章 +2 位作者 梁浩鹏 王乔 李晓旭 《计算机应用研究》 CSCD 北大核心 2024年第4期1112-1116,共5页
针对语音增强网络对全局语音相关特征提取困难、对语音局部上下文信息的捕捉效果不佳的问题,提出了一种基于双分支注意力U-Net的时域语音增强方法,该方法使用U-Net编码器-解码器结构,将单通道带噪语音经过一维卷积后得到的高维时域特征... 针对语音增强网络对全局语音相关特征提取困难、对语音局部上下文信息的捕捉效果不佳的问题,提出了一种基于双分支注意力U-Net的时域语音增强方法,该方法使用U-Net编码器-解码器结构,将单通道带噪语音经过一维卷积后得到的高维时域特征作为输入。首先利用残差连接设计了基于Conformer的残差卷积来增强网络降噪的能力。其次设计了双分支注意力机制结构,利用全局和局部注意力获取带噪语音中更丰富的上下文信息,同时有效表示长序列特征,提取更多样的特征信息。最后结合时域频域损失函数构建了加权损失函数对网络进行训练,提高网络的语音增强性能。使用了多个指标对增强语音的质量和可懂度等进行评价,在公开数据集Voice Bank+DEMAND上的增强后的语音感知质量(PESQ)为3.11,短时可懂度(STOI)为95%,信号失真度(CSIG)为4.44,噪声失真测(CBAK)为3.60,综合质量测度(COVL)为3.81,其中PESQ相较于SE-Conformer提高了7.6%,相较于TSTNN提高了5.1%。实验结果表明,所提方法在语音降噪的各个指标都表现出更优的实验结果,能够完成语音增强任务的相关要求。 展开更多
关键词 语音增强 双分支注意力机制 时域 单通道
下载PDF
深度复数轴向自注意力卷积循环网络的语音增强 被引量:1
18
作者 曹洁 王乔 +3 位作者 梁浩鹏 王宸章 李晓旭 于泓 《计算机系统应用》 2024年第4期60-68,共9页
单通道语音增强任务中相位估计不准确会导致增强语音的质量较差,针对这一问题,提出了一种基于深度复数轴向自注意力卷积循环网络(deep complex axial self-attention convolutional recurrent network,DCACRN)的语音增强方法,在复数域... 单通道语音增强任务中相位估计不准确会导致增强语音的质量较差,针对这一问题,提出了一种基于深度复数轴向自注意力卷积循环网络(deep complex axial self-attention convolutional recurrent network,DCACRN)的语音增强方法,在复数域同时实现了语音幅度信息和相位信息的增强.首先使用基于复数卷积网络的编码器从输入语音信号中提取复数表示的特征,并引入卷积跳连模块用以将特征映射到高维空间进行特征融合,加强信息间的交互和梯度的流动.然后设计了基于轴向自注意力机制的编码器-解码器结构,利用轴向自注意力机制来增强模型的时序建模能力和特征提取能力.最后通过解码器实现对语音信号的重构,同时利用混合损失函数优化网络模型,提升增强语音信号的质量.实验在公开数据集Valentini和DNS Challenge上进行,结果表明所提方法相对于其他模型在客观语音质量评估(perceptual evaluation of speech quality,PESQ)和短时客观可懂度(short-time objective intelligibility,STOI)两项指标上均有提升,在非混响数据集中,PESQ比DCTCRN(deep cosine transform convolutional recurrent network)提高了12.8%,比DCCRN(deep complex convolutional recurrent network)提高了3.9%,验证了该网络模型在语音增强任务中的有效性. 展开更多
关键词 单通道语音增强 复数卷积循环网络 卷积跳连 轴向自注意力机制
下载PDF
GNSS-R外辐射源雷达微弱目标回波盲检测方法
19
作者 温媛媛 白琳 +2 位作者 尚社 宋大伟 王俊 《国防科技大学学报》 EI CAS CSCD 北大核心 2024年第5期121-130,共10页
针对传统全球导航卫星系统反射(global navigation satellite system-reflected, GNSS-R)外辐射源雷达系统所采用的双通道配置结构在信号处理上运算量较大且在工程实现上硬件成本较高的问题,提出一种基于高阶循环累积量的单通道GNSS-R... 针对传统全球导航卫星系统反射(global navigation satellite system-reflected, GNSS-R)外辐射源雷达系统所采用的双通道配置结构在信号处理上运算量较大且在工程实现上硬件成本较高的问题,提出一种基于高阶循环累积量的单通道GNSS-R外辐射源雷达微弱目标回波盲检测方法。利用主成分分析方法将强直达波信号从单通道接收的混合信号中抽取出来;通过直达波信号的高阶循环频率估计出微弱回波信号的高阶循环频率;基于微弱回波信号高阶循环频率与其他信号不同的特性将其从单通道混合信号中提取出来,通过匹配滤波实现目标检测。实验结果表明,所提方法在没有先验信息的情况下能有效提取出微弱目标的回波信号,且与传统二维匹配滤波目标检测方法相比有更好的目标检测性能。 展开更多
关键词 外辐射源雷达 双通道配置 高阶循环累积量 单通道 主成分分析
下载PDF
单通道脊柱内镜与单边双通道脊柱内镜技术治疗腰椎管狭窄症临床疗效分析
20
作者 李想 贺海怿 +5 位作者 李鹏 马琳 郭强 张鹏飞 张凯 聂富祥 《颈腰痛杂志》 2024年第5期834-839,844,共7页
目的探讨单通道脊柱内镜与单边双通道脊柱内镜技术在腰椎管狭窄症的手术减压情况、术后疗效和手术安全性。方法收集该科自2020年7月~2022年7月开展脊柱内镜手术治疗的79例LSS患者资料(包括单通道脊柱内镜手术33例,纳入单通道组;单边双... 目的探讨单通道脊柱内镜与单边双通道脊柱内镜技术在腰椎管狭窄症的手术减压情况、术后疗效和手术安全性。方法收集该科自2020年7月~2022年7月开展脊柱内镜手术治疗的79例LSS患者资料(包括单通道脊柱内镜手术33例,纳入单通道组;单边双通道脊柱内镜手术46例,纳入双通道组)。对两组患者的围手术期指标和疗效指标、减压节段椎间隙硬膜囊横截面积进行分组比较。结果两组患者的手术时间、住院时间和手术并发症情况比较,差异均不显著(P>0.05)。与术前相比较,两组患者术后1个月的腰痛、下肢痛VAS和ODI评分均明显改善(P<0.05),术后12个月这3项指标均进一步改善(P<0.05);上述3项指标的两组间比较,差异均不显著(P>0.05)。术后12个月时,单通道组的优良率90.1%(30/33),双通道组为91.3%(42/46),两组差异不显著(P>0.05)。与术前相比,两组患者术后1个月的硬膜囊横截面积均明显增加(P<0.05),且双通道组的硬膜囊横截面积和术后增加值均显著大于单通道组(P<0.05)。结论单通道与单边双通道脊柱内镜减压术治疗腰椎管狭窄症均可获得满意的减压效果,单通道脊柱内镜手术仅需单一切口,创伤相对更少;而单边双通道脊柱内镜手术则操作更为灵活,减压更为彻底。 展开更多
关键词 腰椎管狭窄症 脊柱微创手术 单通道内镜 单边双通道内镜
下载PDF
上一页 1 2 85 下一页 到第
使用帮助 返回顶部