期刊文献+
共找到23,653篇文章
< 1 2 250 >
每页显示 20 50 100
All-optical controlled-NOT logic gate achieving directional asymmetric transmission based on metasurface doublet 被引量:8
1
作者 Yijia Huang Tianxiao Xiao +9 位作者 Shuai Chen Zhengwei Xie Jie Zheng Jianqi Zhu Yarong Su Weidong Chen Ke Liu Mingjun Tang Peter Müller-Buschbaum Ling Li 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2023年第7期41-49,共9页
Optical logic gates play important roles in all-optical logic circuits,which lie at the heart of the next-generation optical computing technology.However,the intrinsic contradiction between compactness and robustness ... Optical logic gates play important roles in all-optical logic circuits,which lie at the heart of the next-generation optical computing technology.However,the intrinsic contradiction between compactness and robustness hinders the development in this field.Here,we propose a simple design principle that can possess multiple-input-output states according to the incident circular polarization and direction based on the metasurface doublet,which enables controlled-NOT logic gates in infrared region.Therefore,the directional asymmetric electromagnetic transmission can be achieved.As a proof of concept,a spin-dependent Janus metasurface is designed and experimentally verified that four distinct images corresponding to four input states can be captured in the far-field.In addition,since the design method is derived from geometric optics,it can be easily applied to other spectra.We believe that the proposed metasurface doublet may empower many potential applications in chiral imaging,chiroptical spectroscopy and optical computing. 展开更多
关键词 metasurface polarization control asymmetric transmission logic gate
下载PDF
High-efficiency ultra-fast all-optical photonic crystal diode based on the lateral-coupled nonlinear elliptical defect
2
作者 李大星 刘凯柱 +3 位作者 余春龙 张括 刘跃钦 冯帅 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期453-458,共6页
An all-optical Fano-like diode featuring a nonlinear lateral elliptical micro-cavity and a reflecting column in the photonic crystal waveguide is proposed.The asymmetric micro-cavity is constructed by removing one rod... An all-optical Fano-like diode featuring a nonlinear lateral elliptical micro-cavity and a reflecting column in the photonic crystal waveguide is proposed.The asymmetric micro-cavity is constructed by removing one rod and changing the shape of the lateral rod from a circle to an ellipse.A reflecting pillar is also introduced into the waveguide to construct an F-P cavity with the elliptical defect and enhance the asymmetric transmission for the incident light wave transmitting rightwards and leftwards,respectively.By designing the size of the ellipse and optimizing a reflecting rod at a suitable position,a maximum forward light transmittance of-1.14 dB and a minimum backward transmittance of-57.66 dB are achieved at the working wavelength of 1550.47 nm.The corresponding response time is about 10 ps when the intensity of the pump light beam resonant at 637 nm is 3.97 W/μm2. 展开更多
关键词 photonic crystal all-optical diode Fano cavity unidirectional transmission
下载PDF
High-performance chiral all-optical OR logic gate based on topological edge states of valley photonic crystal
3
作者 王晓蓉 费宏明 +6 位作者 林瀚 武敏 康丽娟 张明达 刘欣 杨毅彪 肖连团 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期392-398,共7页
For all-optical communication and information processing,it is necessary to develop all-optical logic gates based on photonic structures that can directly perform logic operations.All-optical logic gates have been dem... For all-optical communication and information processing,it is necessary to develop all-optical logic gates based on photonic structures that can directly perform logic operations.All-optical logic gates have been demonstrated based on conventional waveguides and interferometry,as well as photonic crystal structures.Nonetheless,any defects in those structures will introduce high scattering loss,which compromises the fidelity and contrast ratio of the information process.Based on the spin-valley locking effect that can achieve defect-immune unidirectional transmission of topological edge states in valley photonic crystals(VPCs),we propose a high-performance all-optical logic OR gate based on a VPC structure.By tuning the working bandwidth of the two input channels,we prevent interference between the two channels to achieve a stable and high-fidelity output.The transmittance of both channels is higher than 0.8,and a high contrast ratio of 28.8 dB is achieved.Moreover,the chirality of the logic gate originated from the spin-valley locking effect allows using different circularly polarized light as inputs,representing“1”or“0”,which is highly desired in quantum computing.The device’s footprint is 18μm×12μm,allowing high-density on-chip integration.In addition,this design can be experimentally fabricated using current nanofabrication techniques and will have potential applications in optical communication,information processing,and quantum computing. 展开更多
关键词 topological photonics topological edge state valley photonic crystal all-optical logic gate
下载PDF
引入上下文信息和Attention Gate的GUS-YOLO遥感目标检测算法 被引量:9
4
作者 张华卫 张文飞 +2 位作者 蒋占军 廉敬 吴佰靖 《计算机科学与探索》 CSCD 北大核心 2024年第2期453-464,共12页
目前基于通用YOLO系列的遥感目标检测算法存在并未充分利用图像的全局上下文信息,在特征融合金字塔部分并未充分考虑缩小融合特征之间的语义鸿沟、抑制冗余信息干扰的缺点。在结合YOLO算法优点的基础上提出GUS-YOLO算法,其拥有一个能够... 目前基于通用YOLO系列的遥感目标检测算法存在并未充分利用图像的全局上下文信息,在特征融合金字塔部分并未充分考虑缩小融合特征之间的语义鸿沟、抑制冗余信息干扰的缺点。在结合YOLO算法优点的基础上提出GUS-YOLO算法,其拥有一个能够充分利用全局上下文信息的骨干网络Global Backbone。除此之外,该算法在融合特征金字塔自顶向下的结构中引入Attention Gate模块,可以突出必要的特征信息,抑制冗余信息。另外,为Attention Gate模块设计了最佳的网络结构,提出了网络的特征融合结构U-Net。最后,为克服ReLU函数可能导致模型梯度不再更新的问题,该算法将Attention Gate模块的激活函数升级为可学习的SMU激活函数,提高模型鲁棒性。在NWPU VHR-10遥感数据集上,该算法相较于YOLOV7算法取得宽松指标mAP^(0.50)1.64个百分点和严格指标mAP^(0.75)9.39个百分点的性能提升。相较于目前主流的七种检测算法,该算法取得较好的检测性能。 展开更多
关键词 遥感图像 Global Backbone Attention gate SMU U-neck
下载PDF
Controllable all-optical stochastic logic gates and their delay storages based on the cascaded VCSELs with optical-injection 被引量:5
5
作者 钟东洲 罗伟 许葛亮 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第9期342-354,共13页
Using the dynamical properties of the polarization bistability that depends on the detuning of the injected light,we propose a novel approach to implement reliable all-optical stochastic logic gates in the cascaded ve... Using the dynamical properties of the polarization bistability that depends on the detuning of the injected light,we propose a novel approach to implement reliable all-optical stochastic logic gates in the cascaded vertical cavity surface emitting lasers(VCSELs) with optical-injection.Here,two logic inputs are encoded in the detuning of the injected light from a tunable CW laser.The logic outputs are decoded from the two orthogonal polarization lights emitted from the optically injected VCSELs.For the same logic inputs,under electro-optic modulation,we perform various digital signal processing(NOT,AND,NAND,XOR,XNOR,OR,NOR) in the all-optical domain by controlling the logic operation of the applied electric field.Also we explore their delay storages by using the mechanism of the generalized chaotic synchronization.To quantify the reliabilities of these logic gates,we further demonstrate their success probabilities. 展开更多
关键词 all-optical stochastic logic gates delay storage polarization bistable success probability
下载PDF
All-optical XNOR and AND gates simultaneously realized in a single semiconductor optical amplifier with improved dynamics
6
作者 李培丽 黄德修 +1 位作者 张新亮 朱光喜 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第12期3719-3727,共9页
All-optical XNOR and AND logic gates using four-wave mixing (FWM) and cross-gain modulation (XGM) in a single semiconductor optical amplifier (SOA) with improved dynamics are simultaneously realized. By numerica... All-optical XNOR and AND logic gates using four-wave mixing (FWM) and cross-gain modulation (XGM) in a single semiconductor optical amplifier (SOA) with improved dynamics are simultaneously realized. By numerical simulation, the effects of the input optical wave powers and injection current on the critical factors of the logic gate performances, such as the ON-OFF contrast ratio, the power-output level of the logic '1', and the difference between power outputs of the logic '1', are investigated in detail. In addition, the effect of the counter-propagating CW pump on the gain recovery is analysed. 展开更多
关键词 all-optical logic gate four-wave mixing cross-gain modulation semiconductor optical amplifier
下载PDF
A gated recurrent unit model to predict Poisson’s ratio using deep learning 被引量:1
7
作者 Fahd Saeed Alakbari Mysara Eissa Mohyaldinn +4 位作者 Mohammed Abdalla Ayoub Ibnelwaleed A.Hussein Ali Samer Muhsan Syahrir Ridha Abdullah Abduljabbar Salih 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期123-135,共13页
Static Poisson’s ratio(vs)is crucial for determining geomechanical properties in petroleum applications,namely sand production.Some models have been used to predict vs;however,the published models were limited to spe... Static Poisson’s ratio(vs)is crucial for determining geomechanical properties in petroleum applications,namely sand production.Some models have been used to predict vs;however,the published models were limited to specific data ranges with an average absolute percentage relative error(AAPRE)of more than 10%.The published gated recurrent unit(GRU)models do not consider trend analysis to show physical behaviors.In this study,we aim to develop a GRU model using trend analysis and three inputs for predicting n s based on a broad range of data,n s(value of 0.1627-0.4492),bulk formation density(RHOB)(0.315-2.994 g/mL),compressional time(DTc)(44.43-186.9 μs/ft),and shear time(DTs)(72.9-341.2μ s/ft).The GRU model was evaluated using different approaches,including statistical error an-alyses.The GRU model showed the proper trends,and the model data ranges were wider than previous ones.The GRU model has the largest correlation coefficient(R)of 0.967 and the lowest AAPRE,average percent relative error(APRE),root mean square error(RMSE),and standard deviation(SD)of 3.228%,1.054%,4.389,and 0.013,respectively,compared to other models.The GRU model has a high accuracy for the different datasets:training,validation,testing,and the whole datasets with R and AAPRE values were 0.981 and 2.601%,0.966 and 3.274%,0.967 and 3.228%,and 0.977 and 2.861%,respectively.The group error analyses of all inputs show that the GRU model has less than 5% AAPRE for all input ranges,which is superior to other models that have different AAPRE values of more than 10% at various ranges of inputs. 展开更多
关键词 Static Poisson’s ratio Deep learning gated recurrent unit(GRU) Sand control Trend analysis Geomechanical properties
下载PDF
All-optical logic gate computing for high-speed parallel information processing 被引量:4
8
作者 Shuming Jiao Junwei Liu +6 位作者 Liwen Zhang Feihong Yu Guomeng Zuo Jingming Zhang Fang Zhao Weihao Lin Liyang Shao 《Opto-Electronic Science》 2022年第9期11-32,共22页
Optical computing and optical neural network have gained increasing attention in recent years because of their potential advantages of parallel processing at the speed of light and low power consumption by comparison ... Optical computing and optical neural network have gained increasing attention in recent years because of their potential advantages of parallel processing at the speed of light and low power consumption by comparison with electronic computing.The optical implementation of the fundamental building blocks of a digital computer,i.e.logic gates,has been investigated extensively in the past few decades.Optical logic gate computing is an alternative approach to various analogue optical computing architectures.In this paper,the latest development of optical logic gate computing with different kinds of implementations is reviewed.Firstly,the basic concepts of analogue and digital computing with logic gates in the electronic and optical domains are introduced.And then a comprehensive summary of various optical logic gate schemes including spatial encoding of light field,semiconductor optical amplifiers(SOA),highly nonlinear fiber(HNLF),microscale and nanoscale waveguides,and photonic crystal structures is presented.To conclude,the formidable challenges in developing practical all-optical logic gates are analyzed and the prospects of the future are discussed. 展开更多
关键词 logic gate optical computing artificial intelligence WAVEGUIDE crystal structure
下载PDF
Novel Scheme of All-optical AND Gate Based on Fabry-Perot Semiconductor Optical Amplifier
9
作者 ZHANG Wei QIU Kun LING Yun PANG Ying 《Semiconductor Photonics and Technology》 CAS 2007年第1期63-68,共6页
A novel scheme of all-optical AND gate based on a Fabry-Perot semiconductor optical amplifier(FP-SOA) is proposed and its feasibility is verified by simulation. Using this scheme, all-optical AND gate can be realized ... A novel scheme of all-optical AND gate based on a Fabry-Perot semiconductor optical amplifier(FP-SOA) is proposed and its feasibility is verified by simulation. Using this scheme, all-optical AND gate can be realized with the extinction ratio of 10 dB. The influence of pulse interval and pulse width on the extinction ratio is also investigated. 展开更多
关键词 all-optical packet switching all-optical signal processing all-optical AND gate FP-SOA
下载PDF
Current-collapse suppression and leakage-current decrease in AlGaN/GaN HEMT by sputter-TaN gate-dielectric layer
10
作者 Bosen Liu Guohao Yu +12 位作者 Huimin Jia Jingyuan Zhu Jiaan Zhou Yu Li Bingliang Zhang Zhongkai Du Bohan Guo Lu Wang Qizhi Huang Leifeng Jiang Zhongming Zeng Zhipeng Wei Baoshun Zhang 《Journal of Semiconductors》 EI CAS CSCD 2024年第7期70-75,共6页
In this paper, we explore the electrical characteristics of high-electron-mobility transistors(HEMTs) using a TaN/AlGaN/GaN metal insulating semiconductor(MIS) structure. The high-resistance tantalum nitride(TaN) film... In this paper, we explore the electrical characteristics of high-electron-mobility transistors(HEMTs) using a TaN/AlGaN/GaN metal insulating semiconductor(MIS) structure. The high-resistance tantalum nitride(TaN) film prepared by magnetron sputtering as the gate dielectric layer of the device achieved an effective reduction of electronic states at the TaN/AlGaN interface, and reducing the gate leakage current of the MIS HEMT, its performance was enhanced. The HEMT exhibited a low gate leakage current of 2.15 × 10^(-7) mA/mm and a breakdown voltage of 1180 V. Furthermore, the MIS HEMT displayed exceptional operational stability during dynamic tests, with dynamic resistance remaining only 1.39 times even under 400 V stress. 展开更多
关键词 AlGaN/GaN MIS HEMTs gate dielectric layer DEPLETION-MODE gate reliability I_(on)/I_(off)ratio
下载PDF
Gates joint locally connected network for accurate and robust reconstruction in optical molecular tomography
11
作者 Minghua Zhao Yahui Xiao +2 位作者 Jiaqi Zhang Xin Cao Lin Wang 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第3期11-22,共12页
Optical molecular tomography(OMT)is a potential pre-clinical molecular imaging technique with applications in a variety of biomedical areas,which can provide non-invasive quantitative three-dimensional(3D)information ... Optical molecular tomography(OMT)is a potential pre-clinical molecular imaging technique with applications in a variety of biomedical areas,which can provide non-invasive quantitative three-dimensional(3D)information regarding tumor distribution in living animals.The construction of optical transmission models and the application of reconstruction algorithms in traditional model-based reconstruction processes have affected the reconstruction results,resulting in problems such as low accuracy,poor robustness,and long-time consumption.Here,a gates joint locally connected network(GLCN)method is proposed by establishing the mapping relationship between the inside source distribution and the photon density on surface directly,thus avoiding the extra time consumption caused by iteration and the reconstruction errors caused by model inaccuracy.Moreover,gates module was composed of the concatenation and multiplication operators of three different gates.It was embedded into the network aiming at remembering input surface photon density over a period and allowing the network to capture neurons connected to the true source selectively by controlling three different gates.To evaluate the performance of the proposed method,numerical simulations were conducted,whose results demonstrated good performance in terms of reconstruction positioning accuracy and robustness. 展开更多
关键词 Optical molecular tomography gates module positioning accuracy ROBUSTNESS
下载PDF
Remote entangling gate between a quantum dot spin and a transmon qubit mediated by microwave photons
12
作者 朱行宇 朱乐天 +1 位作者 涂涛 李传锋 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期52-59,共8页
Spin qubits and superconducting qubits are promising candidates for realizing solid-state quantum information processors.Designing a hybrid architecture that combines the advantages of different qubits on the same chi... Spin qubits and superconducting qubits are promising candidates for realizing solid-state quantum information processors.Designing a hybrid architecture that combines the advantages of different qubits on the same chip is a highly desirable but challenging goal.Here we propose a hybrid architecture that utilizes a high-impedance SQUID array resonator as a quantum bus,thereby coherently coupling different solid-state qubits.We employ a resonant exchange spin qubit hosted in a triple quantum dot and a superconducting transmon qubit.Since this hybrid system is highly tunable,it can operate in a dispersive regime,where the interaction between the different qubits is mediated by virtual photons.By utilizing such interactions,entangling gate operations between different qubits can be realized in a short time of 30 ns with a fidelity of up to 96.5%under realistic parameter conditions.Further utilizing this interaction,remote entangled state between different qubits can be prepared and is robust to perturbations of various parameters.These results pave the way for exploring efficient fault-tolerant quantum computation on hybrid quantum architecture platforms. 展开更多
关键词 hybrid quantum architectures circuit quantum electrodynamics entangling gate
下载PDF
Fake News Detection Based on Cross-Modal Message Aggregation and Gated Fusion Network
13
作者 Fangfang Shan Mengyao Liu +1 位作者 Menghan Zhang Zhenyu Wang 《Computers, Materials & Continua》 SCIE EI 2024年第7期1521-1542,共22页
Social media has become increasingly significant in modern society,but it has also turned into a breeding ground for the propagation of misleading information,potentially causing a detrimental impact on public opinion... Social media has become increasingly significant in modern society,but it has also turned into a breeding ground for the propagation of misleading information,potentially causing a detrimental impact on public opinion and daily life.Compared to pure text content,multmodal content significantly increases the visibility and share ability of posts.This has made the search for efficient modality representations and cross-modal information interaction methods a key focus in the field of multimodal fake news detection.To effectively address the critical challenge of accurately detecting fake news on social media,this paper proposes a fake news detection model based on crossmodal message aggregation and a gated fusion network(MAGF).MAGF first uses BERT to extract cumulative textual feature representations and word-level features,applies Faster Region-based ConvolutionalNeuralNetwork(Faster R-CNN)to obtain image objects,and leverages ResNet-50 and Visual Geometry Group-19(VGG-19)to obtain image region features and global features.The image region features and word-level text features are then projected into a low-dimensional space to calculate a text-image affinity matrix for cross-modal message aggregation.The gated fusion network combines text and image region features to obtain adaptively aggregated features.The interaction matrix is derived through an attention mechanism and further integrated with global image features using a co-attention mechanism to producemultimodal representations.Finally,these fused features are fed into a classifier for news categorization.Experiments were conducted on two public datasets,Twitter and Weibo.Results show that the proposed model achieves accuracy rates of 91.8%and 88.7%on the two datasets,respectively,significantly outperforming traditional unimodal and existing multimodal models. 展开更多
关键词 Fake news detection cross-modalmessage aggregation gate fusion network co-attention mechanism multi-modal representation
下载PDF
Study of a Hydraulic Jump in an Asymmetric Trapezoidal Channel with Different Sluice Gates
14
作者 Bouthaina Debabeche Sonia Cherhabil 《Fluid Dynamics & Materials Processing》 EI 2024年第7期1499-1516,共18页
In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and efficiency.In particular,an asym... In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and efficiency.In particular,an asymmetric trapezoidal flume with a length of 7 m and a width of 0.304 m is considered,with the bottom of the flume transversely inclined at an angle of m=0.296 and vertical lateral sides.The corresponding inflow Froude number is allowed to range in the interval(1.40<F1<6.11).The properties of this jump are compared to those of hydraulic jumps in channels with other types of cross-sections.A relationship for calculating hydraulic jump efficiency is proposed for the considered flume.For F1>5,the hydraulic jump is found to be more effective than that occurring in triangular and symmetric trapezoidal channels.Also,when■mes>8 and■>5,the hydraulic jump in the asymmetrical trapezoidal channel downstream of a parallelogram sluice gate is completely formed as opposed to the situation where a triangular sluice is considered. 展开更多
关键词 Asymmetric trapezoidal channel characteristic lengths EFFICIENCY Froude hydraulic jump sequent depths sluice gate
下载PDF
Gated Neural Network-Based Unsteady Aerodynamic Modeling for Large Angles of Attack
15
作者 DENG Yongtao CHENG Shixin MI Baigang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第4期432-443,共12页
Modeling of unsteady aerodynamic loads at high angles of attack using a small amount of experimental or simulation data to construct predictive models for unknown states can greatly improve the efficiency of aircraft ... Modeling of unsteady aerodynamic loads at high angles of attack using a small amount of experimental or simulation data to construct predictive models for unknown states can greatly improve the efficiency of aircraft unsteady aerodynamic design and flight dynamics analysis.In this paper,aiming at the problems of poor generalization of traditional aerodynamic models and intelligent models,an intelligent aerodynamic modeling method based on gated neural units is proposed.The time memory characteristics of the gated neural unit is fully utilized,thus the nonlinear flow field characterization ability of the learning and training process is enhanced,and the generalization ability of the whole prediction model is improved.The prediction and verification of the model are carried out under the maneuvering flight condition of NACA0015 airfoil.The results show that the model has good adaptability.In the interpolation prediction,the maximum prediction error of the lift and drag coefficients and the moment coefficient does not exceed 10%,which can basically represent the variation characteristics of the entire flow field.In the construction of extrapolation models,the training model based on the strong nonlinear data has good accuracy for weak nonlinear prediction.Furthermore,the error is larger,even exceeding 20%,which indicates that the extrapolation and generalization capabilities need to be further optimized by integrating physical models.Compared with the conventional state space equation model,the proposed method can improve the extrapolation accuracy and efficiency by 78%and 60%,respectively,which demonstrates the applied potential of this method in aerodynamic modeling. 展开更多
关键词 large angle of attack unsteady aerodynamic modeling gated neural networks generalization ability
下载PDF
Aerial target threat assessment based on gated recurrent unit and self-attention mechanism
16
作者 CHEN Chen QUAN Wei SHAO Zhuang 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期361-373,共13页
Aerial threat assessment is a crucial link in modern air combat, whose result counts a great deal for commanders to make decisions. With the consideration that the existing threat assessment methods have difficulties ... Aerial threat assessment is a crucial link in modern air combat, whose result counts a great deal for commanders to make decisions. With the consideration that the existing threat assessment methods have difficulties in dealing with high dimensional time series target data, a threat assessment method based on self-attention mechanism and gated recurrent unit(SAGRU) is proposed. Firstly, a threat feature system including air combat situations and capability features is established. Moreover, a data augmentation process based on fractional Fourier transform(FRFT) is applied to extract more valuable information from time series situation features. Furthermore, aiming to capture key characteristics of battlefield evolution, a bidirectional GRU and SA mechanisms are designed for enhanced features.Subsequently, after the concatenation of the processed air combat situation and capability features, the target threat level will be predicted by fully connected neural layers and the softmax classifier. Finally, in order to validate this model, an air combat dataset generated by a combat simulation system is introduced for model training and testing. The comparison experiments show the proposed model has structural rationality and can perform threat assessment faster and more accurately than the other existing models based on deep learning. 展开更多
关键词 target threat assessment gated recurrent unit(GRU) self-attention(SA) fractional Fourier transform(FRFT)
下载PDF
A HybridManufacturing ProcessMonitoringMethod Using Stacked Gated Recurrent Unit and Random Forest
17
作者 Chao-Lung Yang Atinkut Atinafu Yilma +2 位作者 Bereket Haile Woldegiorgis Hendrik Tampubolon Hendri Sutrisno 《Intelligent Automation & Soft Computing》 2024年第2期233-254,共22页
This study proposed a new real-time manufacturing process monitoring method to monitor and detect process shifts in manufacturing operations.Since real-time production process monitoring is critical in today’s smart ... This study proposed a new real-time manufacturing process monitoring method to monitor and detect process shifts in manufacturing operations.Since real-time production process monitoring is critical in today’s smart manufacturing.The more robust the monitoring model,the more reliable a process is to be under control.In the past,many researchers have developed real-time monitoring methods to detect process shifts early.However,thesemethods have limitations in detecting process shifts as quickly as possible and handling various data volumes and varieties.In this paper,a robust monitoring model combining Gated Recurrent Unit(GRU)and Random Forest(RF)with Real-Time Contrast(RTC)called GRU-RF-RTC was proposed to detect process shifts rapidly.The effectiveness of the proposed GRU-RF-RTC model is first evaluated using multivariate normal and nonnormal distribution datasets.Then,to prove the applicability of the proposed model in a realmanufacturing setting,the model was evaluated using real-world normal and non-normal problems.The results demonstrate that the proposed GRU-RF-RTC outperforms other methods in detecting process shifts quickly with the lowest average out-of-control run length(ARL1)in all synthesis and real-world problems under normal and non-normal cases.The experiment results on real-world problems highlight the significance of the proposed GRU-RF-RTC model in modern manufacturing process monitoring applications.The result reveals that the proposed method improves the shift detection capability by 42.14%in normal and 43.64%in gamma distribution problems. 展开更多
关键词 Smart manufacturing process monitoring quality control gated recurrent unit neural network random forest
下载PDF
预测轴承寿命的gate递归单元特征融合域自适应模型
18
作者 曾玉海 程峰 +1 位作者 魏春虎 杨世飞 《机电工程》 CAS 北大核心 2024年第4期613-621,共9页
采用现有的数据驱动模型对不同工况下的轴承剩余使用寿命(RUL)进行预测时,精度会大幅下降。针对这一问题,提出了一种基于门控递归单元特征融合领域自适应(GFFDA)模型的轴承RUL预测方法。首先,采用信号分析方法对轴承振动信号进行了特征... 采用现有的数据驱动模型对不同工况下的轴承剩余使用寿命(RUL)进行预测时,精度会大幅下降。针对这一问题,提出了一种基于门控递归单元特征融合领域自适应(GFFDA)模型的轴承RUL预测方法。首先,采用信号分析方法对轴承振动信号进行了特征提取,并采用特征评价的方法选择出了5个最优特征,在最优特征的基础上,采用粒子群算法优化后的支持向量机的方法对轴承的健康阶段进行了划分;然后,选择目标域和源域退化阶段的最优特征子集作为GFFDA模型的输入,采用源域数据对特征提取器和寿命预测模块进行了预训练;最后,更新了目标特征提取器和寿命预测模块,对目标域的RUL进行了预测;并使用西安交通大学的轴承数据集对该GFFDA模型的有效性进行了验证。研究结果表明:相比于现有的数据驱动模型,GFFDA模型具有更好的跨工况分析能力和更出色的信息提取能力;同时,在对变工况的轴承寿命进行预测时,采用GFFDA模型具有更好的性能。 展开更多
关键词 滚动轴承 剩余使用寿命(RUL) 特征评价 对抗自适应 门控递归单元特征融合领域自适应(GFFDA)模型 数据驱动模型
下载PDF
Dual Gate液晶显示屏栅极制程断路缺陷的分析与改善
19
作者 杨迪一 孔繁林 +6 位作者 胡兴兴 夏莹莹 黄小平 吴成业 郝静 文鑫 莫艳 《数字通信世界》 2024年第2期47-50,共4页
文章探究了光刻工序的水汽和ITO刻蚀工序的药液结晶对DualGate产品栅极制程的断路影响,通过DOE试验得到影响因子的最佳改善条件,使55寸DualGate产品栅极制程的断路缺陷发生率整体降低36%,为公司带来80.2万元的月度收益,能够对其他高端... 文章探究了光刻工序的水汽和ITO刻蚀工序的药液结晶对DualGate产品栅极制程的断路影响,通过DOE试验得到影响因子的最佳改善条件,使55寸DualGate产品栅极制程的断路缺陷发生率整体降低36%,为公司带来80.2万元的月度收益,能够对其他高端产品断路缺陷的改善思路、新工艺设备的设计改进,提供参考。 展开更多
关键词 双栅 断路 试验设计
下载PDF
All-Optical Sampling Using Nonlinear Polarization Rotation in a Single Semiconductor Optical Amplifier 被引量:2
20
作者 张尚剑 张谦述 +2 位作者 李和平 刘永智 刘永 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第6期1031-1035,共5页
We propose a novel all-optical sampling method using nonlinear polarization rotation in a semiconductor optical amplifier. A rate-equation model capable of describing the all-optical sampling mechanism is presented in... We propose a novel all-optical sampling method using nonlinear polarization rotation in a semiconductor optical amplifier. A rate-equation model capable of describing the all-optical sampling mechanism is presented in this paper. Based on this model, we investigate the optimized operating parameters of the proposed system by simulating the output intensity of the probe light as functions of the input polarization angle, the phase induced by the polarization controller, and the ori- entation of the polarization beam splitter. The simulated results show that we can obtain a good linear slope and a large linear dynamic range,which is suitable for all-optical sampling. The operating power of the pump light can be less than lmW. The presented all-optical sampling method can potentially operate at a sampling rate up to hundreds GS/s and needs low optical power. 展开更多
关键词 optical signal processing all-optical sampling semiconductor optical amplifier nonlinear polarization rotation
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部