期刊文献+
共找到10,095篇文章
< 1 2 250 >
每页显示 20 50 100
Vibration attenuation performance of wind turbine tower using a prestressed tuned mass damper under seismic excitation
1
作者 Lei Zhenbo Liu Gang +1 位作者 Wang Hui Hui Yi 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第2期511-524,共14页
With the rapid development of large megawatt wind turbines,the operation environment of wind turbine towers(WTTs)has become increasingly complex.In particular,seismic excitation can create a resonance response and cau... With the rapid development of large megawatt wind turbines,the operation environment of wind turbine towers(WTTs)has become increasingly complex.In particular,seismic excitation can create a resonance response and cause excessive vibration of the WTT.To investigate the vibration attenuation performance of the WTT under seismic excitations,a novel passive vibration control device,called a prestressed tuned mass damper(PS-TMD),is presented in this study.First,a mathematical model is established based on structural dynamics under seismic excitation.Then,the mathematical analytical expression of the dynamic coefficient is deduced,and the parameter design method is obtained by system tuning optimization.Next,based on a theoretical analysis and parameter design,the numerical results showed that the PS-TMD was able to effectively mitigate the resonance under the harmonic basal acceleration.Finally,the time-history analysis method is used to verify the effectiveness of the traditional pendulum tuned mass damper(PTMD)and the novel PS-TMD device,and the results indicate that the vibration attenuation performance of the PS-TMD is better than the PTMD.In addition,the PS-TMD avoids the nonlinear effect due to the large oscillation angle,and has the potential to dissipate hysteretic energy under seismic excitation. 展开更多
关键词 wind turbine tower prestressed tuned mass damper vibration control seismic excitation numerical simulation
下载PDF
Multiscale and Auto-Tuned Semi-Supervised Deep Subspace Clustering and Its Application in Brain Tumor Clustering
2
作者 Zhenyu Qian Yizhang Jiang +4 位作者 Zhou Hong Lijun Huang Fengda Li Khin Wee Lai Kaijian Xia 《Computers, Materials & Continua》 SCIE EI 2024年第6期4741-4762,共22页
In this paper,we introduce a novel Multi-scale and Auto-tuned Semi-supervised Deep Subspace Clustering(MAS-DSC)algorithm,aimed at addressing the challenges of deep subspace clustering in high-dimensional real-world da... In this paper,we introduce a novel Multi-scale and Auto-tuned Semi-supervised Deep Subspace Clustering(MAS-DSC)algorithm,aimed at addressing the challenges of deep subspace clustering in high-dimensional real-world data,particularly in the field of medical imaging.Traditional deep subspace clustering algorithms,which are mostly unsupervised,are limited in their ability to effectively utilize the inherent prior knowledge in medical images.Our MAS-DSC algorithm incorporates a semi-supervised learning framework that uses a small amount of labeled data to guide the clustering process,thereby enhancing the discriminative power of the feature representations.Additionally,the multi-scale feature extraction mechanism is designed to adapt to the complexity of medical imaging data,resulting in more accurate clustering performance.To address the difficulty of hyperparameter selection in deep subspace clustering,this paper employs a Bayesian optimization algorithm for adaptive tuning of hyperparameters related to subspace clustering,prior knowledge constraints,and model loss weights.Extensive experiments on standard clustering datasets,including ORL,Coil20,and Coil100,validate the effectiveness of the MAS-DSC algorithm.The results show that with its multi-scale network structure and Bayesian hyperparameter optimization,MAS-DSC achieves excellent clustering results on these datasets.Furthermore,tests on a brain tumor dataset demonstrate the robustness of the algorithm and its ability to leverage prior knowledge for efficient feature extraction and enhanced clustering performance within a semi-supervised learning framework. 展开更多
关键词 Deep subspace clustering multiscale network structure automatic hyperparameter tuning SEMI-SUPERVISED medical image clustering
下载PDF
Parameters Optimization and Performance Evaluation of the Tuned Inerter Damper for the Seismic Protection of Adjacent Building Structures
3
作者 Xiaofang Kang Jian Wu +1 位作者 Xinqi Wang Shancheng Lei 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期551-593,共43页
In order to improve the seismic performance of adjacent buildings,two types of tuned inerter damper(TID)damping systems for adjacent buildings are proposed,which are composed of springs,inerter devices and dampers in ... In order to improve the seismic performance of adjacent buildings,two types of tuned inerter damper(TID)damping systems for adjacent buildings are proposed,which are composed of springs,inerter devices and dampers in serial or in parallel.The dynamic equations of TID adjacent building damping systems were derived,and the H2 norm criterion was used to optimize and adjust them,so that the system had the optimum damping performance under white noise random excitation.Taking TID frequency ratio and damping ratio as optimization parameters,the optimum analytical solutions of the displacement frequency response of the undamped structure under white noise excitation were obtained.The results showed that compared with the classic TMD,TID could obtain a better damping effect in the adjacent buildings.Comparing the TIDs composed of serial or parallel,it was found that the parallel TIDs had more significant advantages in controlling the peak displacement frequency response,while the H2 norm of the displacement frequency response of the damping system under the coupling of serial TID was smaller.Taking the adjacent building composed of two ten-story frame structures as an example,the displacement and energy collection time history analysis of the adjacent building coupled with the optimum design parameter TIDs were carried out.It was found that TID had a better damping effect in the full-time range compared with the classic TMD.This paper also studied the potential power of TID in adjacent buildings,which can be converted into available power resources during earthquakes. 展开更多
关键词 Adjacent buildings tuned inerter damper(TID) H2 norm optimization vibration control energy harvesting
下载PDF
Classification of Conversational Sentences Using an Ensemble Pre-Trained Language Model with the Fine-Tuned Parameter
4
作者 R.Sujatha K.Nimala 《Computers, Materials & Continua》 SCIE EI 2024年第2期1669-1686,共18页
Sentence classification is the process of categorizing a sentence based on the context of the sentence.Sentence categorization requires more semantic highlights than other tasks,such as dependence parsing,which requir... Sentence classification is the process of categorizing a sentence based on the context of the sentence.Sentence categorization requires more semantic highlights than other tasks,such as dependence parsing,which requires more syntactic elements.Most existing strategies focus on the general semantics of a conversation without involving the context of the sentence,recognizing the progress and comparing impacts.An ensemble pre-trained language model was taken up here to classify the conversation sentences from the conversation corpus.The conversational sentences are classified into four categories:information,question,directive,and commission.These classification label sequences are for analyzing the conversation progress and predicting the pecking order of the conversation.Ensemble of Bidirectional Encoder for Representation of Transformer(BERT),Robustly Optimized BERT pretraining Approach(RoBERTa),Generative Pre-Trained Transformer(GPT),DistilBERT and Generalized Autoregressive Pretraining for Language Understanding(XLNet)models are trained on conversation corpus with hyperparameters.Hyperparameter tuning approach is carried out for better performance on sentence classification.This Ensemble of Pre-trained Language Models with a Hyperparameter Tuning(EPLM-HT)system is trained on an annotated conversation dataset.The proposed approach outperformed compared to the base BERT,GPT,DistilBERT and XLNet transformer models.The proposed ensemble model with the fine-tuned parameters achieved an F1_score of 0.88. 展开更多
关键词 Bidirectional encoder for representation of transformer conversation ensemble model fine-tuning generalized autoregressive pretraining for language understanding generative pre-trained transformer hyperparameter tuning natural language processing robustly optimized BERT pretraining approach sentence classification transformer models
下载PDF
超高层Tuned Mass Damper防震支撑系统技术研究应用 被引量:1
5
作者 付正权 张田庆 +3 位作者 陈俊 闵旭 王海江 张茅 《建筑技术开发》 2023年第S01期105-107,共3页
超高层建筑是现代城市建设的重要标志之一,其高度已经超过了传统建筑的极限。然而,随着建筑高度不断增加,地震的破坏力也越来越强,超高层建筑面临着更加严峻的安全挑战。因此,研究超高层建筑防震支撑系统技术非常重要,Tuned Mass Damper... 超高层建筑是现代城市建设的重要标志之一,其高度已经超过了传统建筑的极限。然而,随着建筑高度不断增加,地震的破坏力也越来越强,超高层建筑面临着更加严峻的安全挑战。因此,研究超高层建筑防震支撑系统技术非常重要,Tuned Mass Damper(TMD)是一种被广泛研究和应用的超高层建筑防震支撑系统技术,TMD最初是在20世纪60年代提出的,最早应用于桥梁上,后来,TMD被引入到建筑领域,并得到广泛的应用。通过精确调节质量、阻尼和弹性等参数来削弱地震引起的建筑物减震效应,从而减少了建筑物因地震造成的损害和崩塌的风险. 展开更多
关键词 超高层建筑 破坏力 防震支撑系统 tuned Mass Damper
下载PDF
Precious Deposits in Sea Salt Culture --Hai Zhou Five Main Tunes
6
作者 JunRong Ban 《Journal of Literature and Art Studies》 2018年第8期1193-1199,共7页
In traditional folk music research, when many questions can not be answered from the literature.Please go to the fields and go to the places where these folk music used to be or is being spread. In the fields, we can ... In traditional folk music research, when many questions can not be answered from the literature.Please go to the fields and go to the places where these folk music used to be or is being spread. In the fields, we can objectively record the traces of the artists 'activities with words, images, or videos. After careful analysis and consideration of the folk tunes while they performed in musician's mouth and hands, we will get unexpected results."Hai Zhou Five Main Tunes (HZFMT)"is a typical case. If you only look at the literature, it is only a local folk narrative tunes. It is not uncommon throughout the country. However, if we go deep into the field investigation, after comparison and analysis, we can see that some of the singles music is the art of Sanqu singing that did not disappear from the Ming and Qing dynasties. These tunes are not lost, but they are handed down from generation to generation in the art population. It is also an art treasure created by the salt merchant culture 展开更多
关键词 Salt merchant culture Hai Zhou Five Main tunes(HZFMT) QUPAI Quyi music
下载PDF
苹果豪赌Tunes
7
《个人电脑》 2004年第3期78-78,共1页
关键词 GarageBand软件 tunes 音效合成 应用软件
下载PDF
Variable stiffness tuned particle dampers for vibration control of cantilever boring bars
8
作者 Xiangying GUO Yunan ZHU +2 位作者 Zhong LUO Dongxing CAO Jihou YANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第12期2163-2186,共24页
This research proposes a novel type of variable stiffness tuned particle damper(TPD)for reducing vibrations in boring bars.The TPD integrates the developments of particle damping and dynamical vibration absorber,whose... This research proposes a novel type of variable stiffness tuned particle damper(TPD)for reducing vibrations in boring bars.The TPD integrates the developments of particle damping and dynamical vibration absorber,whose frequency tuning principle is established through an equivalent theoretical model.Based on the multiphase flow theory of gas-solid,it is effective to obtain the equivalent damping and stiffness of the particle damping.The dynamic equations of the coupled system,consisting of a boring bar with the TPD,are built by Hamilton’s principle.The vibration suppression of the TPD is assessed by calculating the amplitude responses of the boring bar both with and without the TPD by the Newmark-beta algorithm.Moreover,an improvement is proposed to the existing gas-solid flow theory,and a comparative analysis of introducing the stiffness term on the damping effect is presented.The parameters of the TPD are optimized by the genetic algorithm,and the results indicate that the optimized TPD effectively reduces the peak response of the boring bar system. 展开更多
关键词 PARTICLE tuned particle damper(TPD) variable stiffness vibration control
下载PDF
Energy Efficient Hyperparameter Tuned Deep Neural Network to Improve Accuracy of Near-Threshold Processor
9
作者 K.Chanthirasekaran Raghu Gundaala 《Intelligent Automation & Soft Computing》 SCIE 2023年第7期471-489,共19页
When it comes to decreasing margins and increasing energy effi-ciency in near-threshold and sub-threshold processors,timing error resilience may be viewed as a potentially lucrative alternative to examine.On the other... When it comes to decreasing margins and increasing energy effi-ciency in near-threshold and sub-threshold processors,timing error resilience may be viewed as a potentially lucrative alternative to examine.On the other hand,the currently employed approaches have certain restrictions,including high levels of design complexity,severe time constraints on error consolidation and propagation,and uncontaminated architectural registers(ARs).The design of near-threshold circuits,often known as NT circuits,is becoming the approach of choice for the construction of energy-efficient digital circuits.As a result of the exponentially decreased driving current,there was a reduction in performance,which was one of the downsides.Numerous studies have advised the use of NT techniques to chip multiprocessors as a means to preserve outstanding energy efficiency while minimising performance loss.Over the past several years,there has been a clear growth in interest in the development of artificial intelligence hardware with low energy consumption(AI).This has resulted in both large corporations and start-ups producing items that compete on the basis of varying degrees of performance and energy use.This technology’s ultimate goal was to provide levels of efficiency and performance that could not be achieved with graphics processing units or general-purpose CPUs.To achieve this objective,the technology was created to integrate several processing units into a single chip.To accomplish this purpose,the hardware was designed with a number of unique properties.In this study,an Energy Effi-cient Hyperparameter Tuned Deep Neural Network(EEHPT-DNN)model for Variation-Tolerant Near-Threshold Processor was developed.In order to improve the energy efficiency of artificial intelligence(AI),the EEHPT-DNN model employs several AI techniques.The notion focuses mostly on the repercussions of embedded technologies positioned at the network’s edge.The presented model employs a deep stacked sparse autoencoder(DSSAE)model with the objective of creating a variation-tolerant NT processor.The time-consuming method of modifying hyperparameters through trial and error is substituted with the marine predators optimization algorithm(MPO).This method is utilised to modify the hyperparameters associated with the DSSAE model.To validate that the proposed EEHPT-DNN model has a higher degree of functionality,a full simulation study is conducted,and the results are analysed from a variety of perspectives.This was completed so that the enhanced performance could be evaluated and analysed.According to the results of the study that compared numerous DL models,the EEHPT-DNN model performed significantly better than the other models. 展开更多
关键词 Deep learning hyperparameter tuning artificial intelligence near-threshold processor embedded system
下载PDF
A Robust Tuned Random Forest Classifier Using Randomized Grid Search to Predict Coronary Artery Diseases
10
作者 Sameh Abd El-Ghany A.A.Abd El-Aziz 《Computers, Materials & Continua》 SCIE EI 2023年第5期4633-4648,共16页
Coronary artery disease(CAD)is one of themost authentic cardiovascular afflictions because it is an uncommonly overwhelming heart issue.The breakdown of coronary cardiovascular disease is one of the principal sources ... Coronary artery disease(CAD)is one of themost authentic cardiovascular afflictions because it is an uncommonly overwhelming heart issue.The breakdown of coronary cardiovascular disease is one of the principal sources of death all over theworld.Cardiovascular deterioration is a challenge,especially in youthful and rural countries where there is an absence of humantrained professionals.Since heart diseases happen without apparent signs,high-level detection is desirable.This paper proposed a robust and tuned random forest model using the randomized grid search technique to predictCAD.The proposed framework increases the ability of CADpredictions by tracking down risk pointers and learning the confusing joint efforts between them.Nowadays,the healthcare industry has a lot of data but needs to gain more knowledge.Our proposed framework is used for extracting knowledge from data stores and using that knowledge to help doctors accurately and effectively diagnose heart disease(HD).We evaluated the proposed framework over two public databases,Cleveland and Framingham datasets.The datasets were preprocessed by using a cleaning technique,a normalization technique,and an outlier detection technique.Secondly,the principal component analysis(PCA)algorithm was utilized to lessen the feature dimensionality of the two datasets.Finally,we used a hyperparameter tuning technique,randomized grid search,to tune a random forest(RF)machine learning(ML)model.The randomized grid search selected the best parameters and got the ideal CAD analysis.The proposed framework was evaluated and compared with traditional classifiers.Our proposed framework’s accuracy,sensitivity,precision,specificity,and f1-score were 100%.The evaluation of the proposed framework showed that it is an unrivaled perceptive outcome with tuning as opposed to other ongoing existing frameworks. 展开更多
关键词 Coronary artery disease tuned random forest randomized grid search CLASSIFIER
下载PDF
Automated Arabic Text Classification Using Hyperparameter Tuned Hybrid Deep Learning Model
11
作者 Badriyya B.Al-onazi Saud S.Alotaib +4 位作者 Saeed Masoud Alshahrani Najm Alotaibi Mrim M.Alnfiai Ahmed S.Salama Manar Ahmed Hamza 《Computers, Materials & Continua》 SCIE EI 2023年第3期5447-5465,共19页
The text classification process has been extensively investigated in various languages,especially English.Text classification models are vital in several Natural Language Processing(NLP)applications.The Arabic languag... The text classification process has been extensively investigated in various languages,especially English.Text classification models are vital in several Natural Language Processing(NLP)applications.The Arabic language has a lot of significance.For instance,it is the fourth mostly-used language on the internet and the sixth official language of theUnitedNations.However,there are few studies on the text classification process in Arabic.A few text classification studies have been published earlier in the Arabic language.In general,researchers face two challenges in the Arabic text classification process:low accuracy and high dimensionality of the features.In this study,an Automated Arabic Text Classification using Hyperparameter Tuned Hybrid Deep Learning(AATC-HTHDL)model is proposed.The major goal of the proposed AATC-HTHDL method is to identify different class labels for the Arabic text.The first step in the proposed model is to pre-process the input data to transform it into a useful format.The Term Frequency-Inverse Document Frequency(TF-IDF)model is applied to extract the feature vectors.Next,the Convolutional Neural Network with Recurrent Neural Network(CRNN)model is utilized to classify the Arabic text.In the final stage,the Crow Search Algorithm(CSA)is applied to fine-tune the CRNN model’s hyperparameters,showing the work’s novelty.The proposed AATCHTHDL model was experimentally validated under different parameters and the outcomes established the supremacy of the proposed AATC-HTHDL model over other approaches. 展开更多
关键词 Hybrid deep learning natural language processing arabic language text classification parameter tuning
下载PDF
苹果苹果在英国申请"Air Tunes"商标
12
《消费电子》 2017年第1期91-91,共1页
近日外媒发现了一个有趣的事情,在英国商标办公室的数据库中,苹果又提交了“Air Tunes”商标申请。但是在美国专利商标局的数据库搜索“Air Tunes”会得到“该商标已经被注销”的结果。Air Tunes是Air Pay技术的前身,早在2010年秋天,苹... 近日外媒发现了一个有趣的事情,在英国商标办公室的数据库中,苹果又提交了“Air Tunes”商标申请。但是在美国专利商标局的数据库搜索“Air Tunes”会得到“该商标已经被注销”的结果。Air Tunes是Air Pay技术的前身,早在2010年秋天,苹果就将Air Tl unes更名为Air Pay,并且l苹果在2016年11月11日正式注销了Air Tunes这个商标。 展开更多
关键词 美国专利商标局 tunes 苹果 英国 数据库搜索 办公室
下载PDF
创新技术 创新产品——普天TD-SCDMA网络规划工具OpenTunes
13
作者 张艳茹 《电信网技术》 2006年第6期11-11,共1页
随着3G尤其是中国自主创新的TD-SCDMA标准的不断成熟与发展,中国建设3G网络的时间表日益临近。因此,网络规划与优化等问题日益成为各运营商和设备厂商关注的焦点。
关键词 TD-SCDMA标准 网络规划工具 创新技术 OPEN tunes 3G网络 自主创新
下载PDF
Novel Double-Damped Tuned AC Filters in HVDC Systems
14
作者 Rana Shaheer Mehmood Asif Hussain +1 位作者 Usman Ali Muhammad Tariq Mahmood 《Computers, Materials & Continua》 SCIE EI 2023年第4期1467-1482,共16页
This paper presents a performance analysis of novel doubledampedtuned alternating current (AC) filters in high voltage direct current(HVDC) systems. The proposed double-damped tuned AC filters offer theadvantages of i... This paper presents a performance analysis of novel doubledampedtuned alternating current (AC) filters in high voltage direct current(HVDC) systems. The proposed double-damped tuned AC filters offer theadvantages of improved performance of HVDC systems in terms of betterpower quality, high power factor, and lower total harmonic distortion (THD).The system under analysis consists of an 878 km long HVDC transmissionline connecting converter stations at Matiari and Lahore, two major cities inPakistan. The main focus of this research is to design a novel AC filter usingthe equivalent impedance method of two single-tuned and double-dampedtuned AC filters. Additionally, the impact of the damping resistor on the ACchannel is examined. TheTHDof theHVDCsystem with and without currentAC filters was also compared in this research and a double-damped tuned ACfilter was proposed. The results of the simulation represent that the proposeddouble-damped tuned AC filter is far smaller in size, offers better powerquality, and has a much lower THD compared to the AC filters currently inplace in the converter station. The simulation analysis was carried out utilizingpower systems computer-aided design (PSCAD) software. 展开更多
关键词 Double-damped tuned AC filters HARMONICS high voltage DC systems long distance transmission power quality total harmonic distortion
下载PDF
iTunes
15
作者 胡纲 《个人电脑》 2005年第9期255-255,共1页
今年6月底,苹果公司推出了最新的Tunes 4.9版本,该版本最大的特色是支持播客(Podcasting)音频服务。
关键词 苹果公司 tunes 4.9 播客音频服务 计算机软件 网络电台
下载PDF
基于机器学习的数据库系统参数优化方法综述 被引量:2
16
作者 石磊 李天 +3 位作者 高宇飞 卫琳 李翠霞 陶永才 《郑州大学学报(工学版)》 北大核心 2024年第1期1-11,28,共12页
参数优化是影响数据库性能和适应性的关键技术,合理的参数配置对于保障数据库系统的高效运行至关重要,但由于参数较多且参数间具有强关联性,传统参数优化方法难以在高维连续的参数空间中寻找最优配置,机器学习的发展为解决这一难题带来... 参数优化是影响数据库性能和适应性的关键技术,合理的参数配置对于保障数据库系统的高效运行至关重要,但由于参数较多且参数间具有强关联性,传统参数优化方法难以在高维连续的参数空间中寻找最优配置,机器学习的发展为解决这一难题带来新的机遇。通过总结和分析相关工作,将已有工作按照发展时间和特性分为专家决策、静态规则、启发式算法、传统机器学习方法和深度强化学习方法。对数据库参数优化问题进行定义,并说明启发式算法在参数优化问题上的局限性。介绍基于传统机器学习的参数优化方法,包括随机森林、支持向量机、决策树等,描述机器学习方法解决参数优化问题的一般流程并给出一般实现。由于需要大量带标注的数据,传统机器学习模型在适应性和调优能力等方面存在不足。侧重介绍深度强化学习模型的工作原理,定义参数优化问题与深度强化学习模型的映射关系,比较基于深度强化学习的相关工作对数据库性能提升、模型训练时间和涉及的技术,描述基于深度神经网络构建和训练智能体的具体流程。最后,总结已有工作的特点,对当前机器学习在数据库参数优化方面的研究热点和发展方向进行展望,指出多粒度调优、自适应算法和自运维是未来的研究趋势。 展开更多
关键词 数据库系统 参数优化 性能优化 机器学习 强化学习 数据库运维
下载PDF
Abstractive Arabic Text Summarization Using Hyperparameter Tuned Denoising Deep Neural Network
17
作者 Ibrahim M.Alwayle Hala J.Alshahrani +5 位作者 Saud S.Alotaibi Khaled M.Alalayah Amira Sayed A.Aziz Khadija M.Alaidarous Ibrahim Abdulrab Ahmed Manar Ahmed Hamza 《Intelligent Automation & Soft Computing》 2023年第11期153-168,共16页
ive Arabic Text Summarization using Hyperparameter Tuned Denoising Deep Neural Network(AATS-HTDDNN)technique.The presented AATS-HTDDNN technique aims to generate summaries of Arabic text.In the presented AATS-HTDDNN t... ive Arabic Text Summarization using Hyperparameter Tuned Denoising Deep Neural Network(AATS-HTDDNN)technique.The presented AATS-HTDDNN technique aims to generate summaries of Arabic text.In the presented AATS-HTDDNN technique,the DDNN model is utilized to generate the summary.This study exploits the Chameleon Swarm Optimization(CSO)algorithm to fine-tune the hyperparameters relevant to the DDNN model since it considerably affects the summarization efficiency.This phase shows the novelty of the current study.To validate the enhanced summarization performance of the proposed AATS-HTDDNN model,a comprehensive experimental analysis was conducted.The comparison study outcomes confirmed the better performance of the AATS-HTDDNN model over other approaches. 展开更多
关键词 Text summarization deep learning denoising deep neural networks hyperparameter tuning Arabic language
下载PDF
基于RoBERTa和T5的两阶段医学术语标准化
18
作者 周景 崔灿灿 +1 位作者 王梦迪 王泽敏 《计算机系统应用》 2024年第1期280-288,共9页
医学术语标准化作为消除实体歧义性的重要手段,被广泛应用于知识图谱的构建过程之中.针对医学领域涉及大量的专业术语和复杂的表述方式,传统匹配模型往往难以达到较高的准确率的问题,提出语义召回加精准排序的两阶段模型来提升医学术语... 医学术语标准化作为消除实体歧义性的重要手段,被广泛应用于知识图谱的构建过程之中.针对医学领域涉及大量的专业术语和复杂的表述方式,传统匹配模型往往难以达到较高的准确率的问题,提出语义召回加精准排序的两阶段模型来提升医学术语标准化效果.首先在语义召回阶段基于改进的有监督对比学习和RoBERTa-wwm提出语义表征模型CL-BERT,通过CL-BERT生成实体的语义表征向量,根据向量之间的余弦相似度进行召回并得到标准词候选集,其次在精准排序阶段使用T5结合prompt tuning构建语义精准匹配模型,并将FGM对抗训练应用到模型训练中,然后使用精准匹配模型对原词和标准词候选集分别进行精准排序得到最终标准词.采用ccks2019公开数据集进行实验,F1值达到了0.9206,实验结果表明所提出的两阶段模型具有较高的性能,为实现医学术语标准化提供了新思路. 展开更多
关键词 医学术语标准化 RoBERTa-wwm 对比学习 T5 prompt tuning 知识图谱
下载PDF
LCC-MMC混合三端直流输电系统送端交流故障下的不间断运行协调控制策略 被引量:1
19
作者 唐岚 濮永现 +4 位作者 邢超 耿樾 王成磊 束洪春 卜祥帅 《电力自动化设备》 EI CSCD 北大核心 2024年第1期174-180,共7页
为实现基于电网换相换流器与模块化多电平换流器(LCC-MMC)的混合三端直流输电系统送端交流故障下的直流低电压穿越,提出兼顾传输容量与响应速度的自适应电压协调控制策略及有功功率分配策略。在维持故障期间功率续传的前提下,定量分析... 为实现基于电网换相换流器与模块化多电平换流器(LCC-MMC)的混合三端直流输电系统送端交流故障下的直流低电压穿越,提出兼顾传输容量与响应速度的自适应电压协调控制策略及有功功率分配策略。在维持故障期间功率续传的前提下,定量分析了模块化多电平换流器(MMC)的降压值以减少传输功率的绝对值损失量,并设计MMC根据本地直流电流偏差快速减投子模块总数的降压方式;考虑到半桥型MMC的调制比约束,设计正极MMC定量吸收无功功率与负极MMC动态调整交流电压参考值的换流站极间协同控制策略;同时,为抑制从站的过电流及避免送端严重交流故障时主站的潮流反转,提出各受端换流站有功功率自适应调整的控制方式。最后通过对输电系统送端交流电压跌落不同幅度时的故障穿越效果进行仿真分析,验证了所提控制策略的有效性。 展开更多
关键词 LCC-MMC 直流低电压穿越 自适应电压协调控制 自适应功率分配 定量整定
下载PDF
基于微调原型网络的小样本敏感信息识别方法 被引量:1
20
作者 余正涛 关昕 +2 位作者 黄于欣 张思琦 赵庆珏 《中文信息学报》 CSCD 北大核心 2024年第1期115-123,共9页
敏感信息识别主要是指识别互联网上涉及色情、毒品、邪教、暴力等类型的敏感信息,现有的敏感信息识别通常将其看作文本分类任务,但由于缺乏大规模的敏感信息标注数据,分类效果不佳。该文提出一种基于微调原型网络的小样本敏感信息识别方... 敏感信息识别主要是指识别互联网上涉及色情、毒品、邪教、暴力等类型的敏感信息,现有的敏感信息识别通常将其看作文本分类任务,但由于缺乏大规模的敏感信息标注数据,分类效果不佳。该文提出一种基于微调原型网络的小样本敏感信息识别方法,在小样本学习框架下,利用快速适应的微调原型网络来缓解元训练阶段通用新闻领域和元测试阶段敏感信息数据差异大的问题。首先,在元训练阶段,基于通用新闻领域的分类数据训练模型来学习通用知识,同时在训练过程中经过两阶段梯度更新,得到一组对新任务敏感的快速适应初始参数,然后在元测试阶段敏感文本数据集的新任务上,冻结模型部分参数并使用支持集进一步微调,使模型更好地泛化到敏感识别领域上。实验结果证明,相比当前最优的小样本分类模型,该文提出的快速适应微调策略的原型网络显著提升了敏感信息识别效果。 展开更多
关键词 敏感信息识别 小样本学习 微调策略 原型网络
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部