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引入上下文信息和Attention Gate的GUS-YOLO遥感目标检测算法 被引量:8
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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
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A gated recurrent unit model to predict Poisson’s ratio using deep learning 被引量:1
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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
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Current-collapse suppression and leakage-current decrease in AlGaN/GaN HEMT by sputter-TaN gate-dielectric layer
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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
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Gates joint locally connected network for accurate and robust reconstruction in optical molecular tomography
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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
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Remote entangling gate between a quantum dot spin and a transmon qubit mediated by microwave photons
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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
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Fake News Detection Based on Cross-Modal Message Aggregation and Gated Fusion Network
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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
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Study of a Hydraulic Jump in an Asymmetric Trapezoidal Channel with Different Sluice Gates
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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
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Aerial target threat assessment based on gated recurrent unit and self-attention mechanism
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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)
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A HybridManufacturing ProcessMonitoringMethod Using Stacked Gated Recurrent Unit and Random Forest
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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
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预测轴承寿命的gate递归单元特征融合域自适应模型
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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
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Dual Gate液晶显示屏栅极制程断路缺陷的分析与改善
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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
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Molecular Mechanisms of Cyclic Nucleotide-Gated Ion Channel Gating 被引量:1
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作者 王正朝 蒋永清 +3 位作者 卢立志 黄瑞华 侯清超 石放雄 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第6期477-485,共9页
Cyclic nucleotide-gated ion channels (CNGs) are distributed most widely in the neuronal cell. Great progress has been made in molecular mechanisms of CNG channel gating in the recent years. Results of many experimen... Cyclic nucleotide-gated ion channels (CNGs) are distributed most widely in the neuronal cell. Great progress has been made in molecular mechanisms of CNG channel gating in the recent years. Results of many experiments have indicated that the stoichiometry and assembly of CNG channels affect their property and gating. Experiments of CNG mutants and analyses of cys- teine accessibilities show that cyclic nucleotide-binding domains (CNBD) bind cyclic nucleotides and subsequently conformational changes occurred followed by the concerted or cooperative conformational change of all four subunits during CNG gating. In order to provide theoretical assistances for further investigation on CNG channels, especially regarding the disease pathogenesis of ion channels, this paper reviews the latest progress on mechanisms of CNG channels, functions of subunits, processes of subunit assembly, and conformational changes of subunit regions during gating. 展开更多
关键词 cyclic nucleotide-gated ion channel (CNG) conformational change gating
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基于Leaky Noisy-or Gate和贝叶斯网络的光伏发电项目施工风险评估方法 被引量:2
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作者 董华珊 侯学良 《科技和产业》 2023年第2期218-223,共6页
针对复杂多变的光伏发电项目施工风险评估问题,利用Leaky Noisy-or Gate模型整合历史经验和专家知识来确定贝叶斯网络参数并建立光伏施工风险的贝叶斯网络模型,同时采用Netica仿真分析,对施工风险进行有效预测并诊断识别出关键性风险和... 针对复杂多变的光伏发电项目施工风险评估问题,利用Leaky Noisy-or Gate模型整合历史经验和专家知识来确定贝叶斯网络参数并建立光伏施工风险的贝叶斯网络模型,同时采用Netica仿真分析,对施工风险进行有效预测并诊断识别出关键性风险和敏感性风险,以便管理者精准施策、管控风险。为验证该方法的有效性,以Z项目为例进行建模仿真。结果表明,其施工风险等级为中等,与实际相符。 展开更多
关键词 光伏项目 贝叶斯网络 Leaky Noisy-or Gate模型 敏感性分析 关键性风险
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All-optical controlled-NOT logic gate achieving directional asymmetric transmission based on metasurface doublet 被引量:6
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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
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Radar Quantitative Precipitation Estimation Based on the Gated Recurrent Unit Neural Network and Echo-Top Data 被引量:2
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作者 Haibo ZOU Shanshan WU Miaoxia TIAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第6期1043-1057,共15页
The Gated Recurrent Unit(GRU) neural network has great potential in estimating and predicting a variable. In addition to radar reflectivity(Z), radar echo-top height(ET) is also a good indicator of rainfall rate(R). I... The Gated Recurrent Unit(GRU) neural network has great potential in estimating and predicting a variable. In addition to radar reflectivity(Z), radar echo-top height(ET) is also a good indicator of rainfall rate(R). In this study, we propose a new method, GRU_Z-ET, by introducing Z and ET as two independent variables into the GRU neural network to conduct the quantitative single-polarization radar precipitation estimation. The performance of GRU_Z-ET is compared with that of the other three methods in three heavy rainfall cases in China during 2018, namely, the traditional Z-R relationship(Z=300R1.4), the optimal Z-R relationship(Z=79R1.68) and the GRU neural network with only Z as the independent input variable(GRU_Z). The results indicate that the GRU_Z-ET performs the best, while the traditional Z-R relationship performs the worst. The performances of the rest two methods are similar.To further evaluate the performance of the GRU_Z-ET, 200 rainfall events with 21882 total samples during May–July of 2018 are used for statistical analysis. Results demonstrate that the spatial correlation coefficients, threat scores and probability of detection between the observed and estimated precipitation are the largest for the GRU_Z-ET and the smallest for the traditional Z-R relationship, and the root mean square error is just the opposite. In addition, these statistics of GRU_Z are similar to those of optimal Z-R relationship. Thus, it can be concluded that the performance of the GRU_ZET is the best in the four methods for the quantitative precipitation estimation. 展开更多
关键词 quantitative precipitation estimation Gated Recurrent Unit neural network Z-R relationship echo-top height
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基于Golden Gate高效构建psiCHECK双荧光素酶报告基因的方法及应用
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作者 杜雅婷 于文君 +2 位作者 李燕 付元磊 孙考祥 《山东第一医科大学(山东省医学科学院)学报》 CAS 2023年第3期180-185,共6页
目的 基于Golden Gate技术构建psiCHECK-CcdB重组双荧光素酶报告载体,并探讨其能否用于RNA干扰(RNA interference, RNAi)药物筛选。方法 通过聚合酶链反应(polymerase chain reaction,PCR)扩增CcdB致死基因、氯霉素基因与Golden Gate组... 目的 基于Golden Gate技术构建psiCHECK-CcdB重组双荧光素酶报告载体,并探讨其能否用于RNA干扰(RNA interference, RNAi)药物筛选。方法 通过聚合酶链反应(polymerase chain reaction,PCR)扩增CcdB致死基因、氯霉素基因与Golden Gate组装所需的BsmBI酶切位点,将其克隆至psiCHECK-2载体,构建出重组载体psiCHECK-CcdB。利用2种大肠杆菌DB3.1与DH5α对该载体的致死效率进行检测,选用1 387 bp大小的外源片段克隆至psiCHECK-CcdB载体,检测其连接效率,并验证重组载体能否发挥双荧光素酶报告系统功能,监测目的基因的表达变化。结果 菌落PCR以及测序鉴定psiCHECK-CcdB重组质粒构建成功,该质粒可有效致死无法耐受CcdB毒素的大肠杆菌DH5α菌株,在DB3.1菌株中正常生长。采用Golden Gate的方法可将外源片段简单快速克隆至psiCHECKCcdB载体中,连接效率显著提高且低背景克隆。通过测定双荧光素酶表达强度,证实了小干扰RNA(small interfering RNA,siRNA)靶向性结合目的基因可显著下调荧光素酶的表达,成功发挥双荧光素酶报告基因功能。结论 本研究成功构建了psiCHECK-CcdB重组双荧光素酶报告载体,应用Golden Gate组装技术,简化了实验操作流程,降低了实验成本,具备较高的阳性克隆率与多片段一次性组装的潜力,在RNAi药物筛选领域应用前景广阔。 展开更多
关键词 Golden Gate CcdB基因 双荧光素酶报告基因 分子克隆 RNAi药物筛选
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An integrated split and dummy gates MOSFET with fast turn-off and reverse recovery characteristics
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作者 陈伟中 牟柳亭 +2 位作者 秦海峰 张红升 韩郑生 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期545-550,共6页
A power MOSFET with integrated split gate and dummy gate(SD-MOS) is proposed and demonstrated by the TCAD SENTAURUS.The split gate is surrounded by the source and shielded by the dummy gate.Consequently,the coupling a... A power MOSFET with integrated split gate and dummy gate(SD-MOS) is proposed and demonstrated by the TCAD SENTAURUS.The split gate is surrounded by the source and shielded by the dummy gate.Consequently,the coupling area between the split gate and the drain electrode is reduced,thus the gate-to-drain charge(Q_(GD)),reverse transfer capacitance(C_(RSS)) and turn-off loss(E_(off)) are significantly decreased.Moreover,the MOS-channel diode is controlled by the dummy gate with ultra-thin gate oxide t_(ox),which can be turned on before the parasitic P-base/N-drift diode at the reverse conduction,then the majority carriers are injected to the N-drift to attenuate the minority injection.Therefore,the reverse recovery charge(Q_(RR)),time(T_(RR)) and peak current(I_(RRM)) are effectively reduced at the reverse freewheeling state.Additionally,the specific on-resistance(R_(on,sp)) and breakdown voltage(BV) are also studied to evaluate the static properties of the proposed SD-MOS.The simulation results show that the Q_(GD) of 6 nC/cm^(2),the C_(RSS) of 1.1 pF/cm^(2) at the V_(DS) of 150 V,the QRR of 1.2 μC/cm^(2) and the R_(on,sp) of 8.4 mΩ·cm^(2) are obtained,thus the figures of merit(FOM) including Q_(GD) ×R_(on,sp) of50 nC·mΩ,E_(off) × R_(on,sp) of 0.59 mJ·mΩ and the Q_(RR) × R_(on,sp) of 10.1 μC·mΩ are achieved for the proposed SD-MOS. 展开更多
关键词 MOSFET split gate dummy gate TURN-OFF and reverse recovery
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Low switching loss and increased short-circuit capability split-gate SiC trench MOSFET with p-type pillar
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作者 沈培 王颖 +2 位作者 李兴冀 杨剑群 曹菲 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期682-689,共8页
A split-gate SiC trench gate MOSFET with stepped thick oxide, source-connected split-gate(SG), and p-type pillar(ppillar) surrounded thick oxide shielding region(GSDP-TMOS) is investigated by Silvaco TCAD simulations.... A split-gate SiC trench gate MOSFET with stepped thick oxide, source-connected split-gate(SG), and p-type pillar(ppillar) surrounded thick oxide shielding region(GSDP-TMOS) is investigated by Silvaco TCAD simulations. The sourceconnected SG region and p-pillar shielding region are introduced to form an effective two-level shielding, which reduces the specific gate–drain charge(Q_(gd,sp)) and the saturation current, thus reducing the switching loss and increasing the short-circuit capability. The thick oxide that surrounds a p-pillar shielding region efficiently protects gate oxide from being damaged by peaked electric field, thereby increasing the breakdown voltage(BV). Additionally, because of the high concentration in the n-type drift region, the electrons diffuse rapidly and the specific on-resistance(Ron,sp) becomes smaller.In the end, comparing with the bottom p~+ shielded trench MOSFET(GP-TMOS), the Baliga figure of merit(BFOM,BV~2/R_(on,sp)) is increased by 169.6%, and the high-frequency figure of merit(HF-FOM, R_(on,sp) × Q_(gd,sp)) is improved by310%, respectively. 展开更多
关键词 SiC gate trench MOSFET gate oxide reliability switching loss gate–drain charge(Q_(gd sp)) short circuit
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Reverse gate leakage mechanism of AlGaN/GaN HEMTs with Au-free gate
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作者 蒋鑫 李晨浩 +6 位作者 羊硕雄 梁家豪 来龙坤 董青杨 黄威 刘新宇 罗卫军 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期441-448,共8页
The reverse gate leakage mechanism of W-gate and Ti N-gate AlGaN/GaN high-electron-mobility transistors(HEMTs)with N2plasma surface treatment is investigated using current–voltage(I–V)and capacitance–voltage(C–V)c... The reverse gate leakage mechanism of W-gate and Ti N-gate AlGaN/GaN high-electron-mobility transistors(HEMTs)with N2plasma surface treatment is investigated using current–voltage(I–V)and capacitance–voltage(C–V)characteristics and theoretical calculation analysis.It is found that the main reverse gate leakage mechanism of both devices is the trapassisted tunneling(TAT)mechanism in the entire reverse bias region(-30 V to 0 V).It is also found that the reverse gate leakage current of the W-gate Al GaN/GaN HEMTs is smaller than that of the TiN gate at high reverse gate bias voltage.Moreover,the activation energies of the extracted W-gate and Ti N-gate AlGaN/GaN HEMTs are 0.0551 e V–0.127 eV and0.112 eV–0.201 eV,respectively. 展开更多
关键词 ALGAN/GAN trap-assisted tunneling(TAT) W gate TiN gate
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Ambipolar performance improvement of the C-shaped pocket TFET with dual metal gate and gate–drain underlap
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作者 赵梓淼 陈子馨 +9 位作者 刘伟景 汤乃云 刘江南 刘先婷 李宣霖 潘信甫 唐敏 李清华 白伟 唐晓东 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期700-707,共8页
Dual-metal gate and gate–drain underlap designs are introduced to reduce the ambipolar current of the device based on the C-shaped pocket TFET(CSP-TFET).The effects of gate work function and gate–drain underlap leng... Dual-metal gate and gate–drain underlap designs are introduced to reduce the ambipolar current of the device based on the C-shaped pocket TFET(CSP-TFET).The effects of gate work function and gate–drain underlap length on the DC characteristics and analog/RF performance of CSP-TFET devices,such as the on-state current(I_(on)),ambipolar current(I_(amb)),transconductance(g_(m)),cut-off frequency(f_(T))and gain–bandwidth product(GBP),are analyzed and compared in this work.Also,a combination of both the dual-metal gate and gate–drain underlap designs has been proposed for the C-shaped pocket dual metal underlap TFET(CSP-DMUN-TFET),which contains a C-shaped pocket area that significantly increases the on-state current of the device;this combination design substantially reduces the ambipolar current.The results show that the CSP-DMUN-TFET demonstrates an excellent performance,including high I_(on)(9.03×10^(-4)A/μm),high I_(on)/I_(off)(~10^(11)),low SS_(avg)(~13 mV/dec),and low I_(amb)(2.15×10^(-17)A/μm).The CSP-DMUN-TFET has the capability to fully suppress ambipolar currents while maintaining high on-state currents,making it a potential replacement in the next generation of semiconductor devices. 展开更多
关键词 tunnel field effect transistor ambipolar current dual metal gate gate–drain underlap
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