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An application of matching pursuit time-frequency decomposition method using multi-wavelet dictionaries 被引量:1
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作者 Zhao Tianzi Song Wei 《Petroleum Science》 SCIE CAS CSCD 2012年第3期310-316,共7页
In the time-frequency analysis of seismic signals, the matching pursuit algorithm is an effective tool for non-stationary signals, and has high time-frequency resolution and a transient structure with local self-adapt... In the time-frequency analysis of seismic signals, the matching pursuit algorithm is an effective tool for non-stationary signals, and has high time-frequency resolution and a transient structure with local self-adaption. We expand the time-frequency dictionary library with Ricker, Morlet, and mixed phase seismic wavelets, to make the method more suitable for seismic signal time-frequency decomposition. In this paper, we demonstrated the algorithm theory using synthetic seismic data, and tested the method using synthetic data with 25% noise. We compared the matching pursuit results of the time-frequency dictionaries. The results indicated that the dictionary which matched the signal characteristics better would obtain better results, and can reflect the information of seismic data effectively. 展开更多
关键词 Matching pursuit seismic attenuation wavelet transform Wigner Ville distribution time- frequency dictionary
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Distribution and exploration direction of medium-and large-sized marine carbonate gas fields in Sichuan Basin, SW China 被引量:5
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作者 MA Xinhua YANG Yu +1 位作者 WEN Long LUO Bing 《Petroleum Exploration and Development》 2019年第1期1-15,共15页
Based on the analysis of the basic characteristics of medium-and large-sized marine gas fields in Sichuan Basin, combined with the division of major reservoir forming geological units in the marine craton stage and th... Based on the analysis of the basic characteristics of medium-and large-sized marine gas fields in Sichuan Basin, combined with the division of major reservoir forming geological units in the marine craton stage and their control on key hydrocarbon accumulation factors, the distribution law of medium-and large-sized marine carbonate gas fields in the basin was examined and the exploration direction was pointed out. Through the analysis of the periodic stretching-uplifting background, it is concluded that five large scale paleo-rifts, three large scale paleo-uplifts, five large scale paleo erosion surfaces were formed in the marine craton stage of Sichuan Basin, and these geological units control the key reservoir forming factors of medium and large sized gas fields:(1) Large-scale paleo-rifts control the distribution of high-quality hydrocarbon generation centers.(2) The margin of large-scale paleo-rifts, high position of paleo-uplifts and paleo erosion surfaces control the distribution of high-quality reservoirs.(3) Large-scale paleo-rifts, paleo-uplifts, paleo erosion surfaces and present tectonic setting jointly control the formation of many types of large and medium-sized traps.(4) Natural gas accumulation is controlled by the inheritance evolution of traps in large geological units. Based on the comparative analysis of the distribution characteristics of medium-and large-sized gas fields and large geological units, it is proposed that the superimposition relationship between single or multiple geological units and the present structure controls the distribution of medium-and large-sized gas fields, and the "three paleo" superimposed area is the most advantageous. According to the above rules, the main exploration fields and directions of medium-and large-sized marine carbonate gas fields in Sichuan Basin include periphery of Deyang-Anyue paleo-rift, eastern margin of Longmenshan paleo-rift, margins of Kaijiang-Liangping oceanic trough and Chengkou-western Hubei oceanic trough, the high part of the subaqueous paleo-uplifts around Central Sichuan, paleo erosion surfaces of the top boundary of Maokou Formation in eastern and southern Sichuan Basin, paleo erosion surfaces of the top boundary of the Leikoupo Formation in central and western Sichuan Basin. 展开更多
关键词 Sichuan Basin marine CARBONATES medium-and large-sized gas fields GEOLOGIC unit reservoir forming factors paleo-rifts paleo-uplifts paleo erosion surfaces
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Modeling and simulation of 3D thermal stresses of large-sized castings in solidification processes 被引量:2
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作者 J.Q.Wang D.W.Yu +2 位作者 X.Sun S.F.Su B.Z.Li 《China Foundry》 SCIE CAS 2004年第S1期20-24,共5页
When heavy machines and large scaled receiver system of communication equipment are manufactured, it always needs to produce large-sized steel castings, aluminum castings and etc. Some defects of hot cracking by therm... When heavy machines and large scaled receiver system of communication equipment are manufactured, it always needs to produce large-sized steel castings, aluminum castings and etc. Some defects of hot cracking by thermal stress often appear during solidification process as these castings are produced, which results in failure of castings. Therefore predicting the effects of technological parameters for production of castings on the thermal stress during solidification process becomes an important means. In this paper, the mathematical models have been established and numerical calculation of temperature fields by using finite difference method (FDM) and then thermal stress fields by using finite element method (FEM) during solidification process of castings have been carried out. The technological parameters of production have been optimized by the results of calculation and the defects of hot cracking have been eliminated. Modeling and simulation of 3D thermal stress during solidification processes of large-sized castings provided a scientific basis, which promoted further development of advanced manufacturing technique. 展开更多
关键词 large-sized castings simulation of 3D temperature fields simulation of 3D thermal stress fields defect of hot cracking solidification process
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Rolling Fatigue Test of Large-Sized UHPC Member for Cable Stayed Bridge 被引量:2
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作者 Jeong-Rae Cho Young Jin Kim +2 位作者 Jong Sup Park Eun Suk Choi Won Jong Chin 《Engineering(科研)》 2012年第10期646-654,共9页
Recently, research strives to apply Ultra High Performance Concrete (UHPC) to large-sized structures owing to its remarkable mechanical performance and durability compared to normal concrete. The Korea Institute of Co... Recently, research strives to apply Ultra High Performance Concrete (UHPC) to large-sized structures owing to its remarkable mechanical performance and durability compared to normal concrete. The Korea Institute of Construction Technology proposed SuperBridge800, an edge girder type UHPC cable stayed bridge with central span of 800 m, through its detailed design. The bridge is designed to be erected through the connection of precast UHPC segments. The precast UHPC segment is monolithically composed of one ribbed deck slab and edge girders at each side. The connection between the precast segments is achieved by steel bars at the edge girders and by UHPC cast-in-place wet joint at the slab. Despite of the outstanding mechanical performance of UHPC, the fabrication of large-sized members is a difficult task since UHPC hardens faster than normal concrete and requires a special curing process. Therefore, the constructability of large-sized UHPC segment should be secured to achieve SuperBridge800. Besides, the performance of the connection between segments should also be guaranteed, especially in terms of the fatigue performance of the UHPC cast-in-place joint, which constitutes a weak point. To that goal, two half-scaled UHPC segments are manufactured and the constructability is examined by fabricating a large-sized UHPC member connected with respect to the design conditions. This study conducts rolling fatigue test on the so-fabricated large-sized UHPC member. Rolling fatigue test is carried out up to 2 million cycles considering actual vehicle load at each center and quarter points of the member. The test results confirm that the service limit state is satisfied. 展开更多
关键词 UHPC CABLE Stayed BRIDGE ROLLING FATIGUE Test large-sized UHPC MEMBER
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Comparison and Contrast of Paper-based and On-line Dictionaries
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作者 王雪 《海外英语》 2014年第6X期244-245,共2页
This paper explores the advantages and disadvantages of paper printed and on-line dictionaries in terms of macrostructure and microstructure,availability,portability and practicality etc.Different kinds of dictionarie... This paper explores the advantages and disadvantages of paper printed and on-line dictionaries in terms of macrostructure and microstructure,availability,portability and practicality etc.Different kinds of dictionaries have unique features that cannot be fully replaced by other kinds. 展开更多
关键词 dictionaries MACROSTRUCTURE MICROSTRUCTURE advanta
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Experimental investigation and numerical simulation of large-sized aluminum tube extrusion forming
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作者 吕亚臣 骆俊廷 +1 位作者 马春荣 徐岩 《Journal of Central South University》 SCIE EI CAS 2008年第S2期293-295,共3页
Large-sized aluminum tube has big section effect, aspect ratio and thin thickness, so that the extrusion technology is complex and the large specific pressure is generated in extrusion cavity. The temperature variatio... Large-sized aluminum tube has big section effect, aspect ratio and thin thickness, so that the extrusion technology is complex and the large specific pressure is generated in extrusion cavity. The temperature variation and velocity effect is difficult to control. The extrusion forming of large-sized aluminum tube was researched and simulated. Three-dimensional thermo-mechanical coupled finite element model was constructed and appropriate boundary conditions were given out. The results show that large-sized aluminum tube can be formed by isothermal extrusion through controlling the extrusion velocity and founding the relationship between extrusion velocity and extrusion temperature. 展开更多
关键词 large-sized ALUMINUM TUBE EXTRUSION NUMERICAL simulation
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Low-Rank Sparse Representation with Pre-Learned Dictionaries and Side Information for Singing Voice Separation
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作者 Chenghong Yang Hongjuan Zhang 《Advances in Pure Mathematics》 2018年第4期419-427,共9页
At present, although the human speech separation has achieved fruitful results, it is not ideal for the separation of singing and accompaniment. Based on low-rank and sparse optimization theory, in this paper, we prop... At present, although the human speech separation has achieved fruitful results, it is not ideal for the separation of singing and accompaniment. Based on low-rank and sparse optimization theory, in this paper, we propose a new singing voice separation algorithm called Low-rank, Sparse Representation with pre-learned dictionaries and side Information (LSRi). The algorithm incorporates both the vocal and instrumental spectrograms as sparse matrix and low-rank matrix, meanwhile combines pre-learning dictionary and the reconstructed voice spectrogram form the annotation. Evaluations on the iKala dataset show that the proposed methods are effective and efficient for singing voice separation. 展开更多
关键词 SINGING VOICE SEPARATION Low-Rank and Sparse DICTIONARY Learning
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Analyzing verbs' definitions in learner's dictionaries based on the schema theory 被引量:1
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作者 YU Ping-fang XU Jing DU Jia-li 《Sino-US English Teaching》 2009年第5期6-10,共5页
关键词 动词 行动模式 英语 学习方法
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On Lexicographical Translation in Bilingual Dictionaries and its Multi-disciplinary Theoretical Basis
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作者 Wei Xiangqing 《宏观语言学》 2007年第1期171-179,共9页
Traditionally, in the field of bilingual lexicography, the main task for lexicographers is to provide lexical equivalents in bilingual dictionaries by all possible means. And accordingly, how to provide appropriate or... Traditionally, in the field of bilingual lexicography, the main task for lexicographers is to provide lexical equivalents in bilingual dictionaries by all possible means. And accordingly, how to provide appropriate or satisfying translation equivalents in bilingual dictionaries is always the centre of attention in bilingual metalexicography. However, the history of bilingual lexicography shows that it has never been an easy task, because of linguistic and cultural anisomorphism. The usual compromise made by most lexicographers is to introduce partial or explanatory equivalents. This recourse means that most bilingual lexicographers, unfortunately, more than often, fail to meet the needs of foreign language learners. Certain misconceptions about the translation equivalents emerge among the language learners, which explains the awkward situation that besets bilingual exicographers. The present contribution aims at perceiving lexicographical translation as a dynamic process by which an adequate semantic system in the target language would be set up to serve as a functionally equivalent defining system. By doing this, bilingual lexicographers should establish a powerful target language semantic network, in which lexicographical sections like verbal illustrations, usage notes and etymologies, etc. would be considered together with the translation equivalents as an integrated whole. This is an attempt to describe the essential features of lexicographical translation and its multi-disciplinary theoretical basis, in the hope that future practice in bilingual lexicography might be improved. 展开更多
关键词 BILINGUAL dictionaries lexicographical TRANSLATION MULTI-DISCIPLINARY THEORETICAL BASIS
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Major Companies Producing Large-Sized Castings and Their Capacity in Consecutive Three Years
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《China Foundry》 SCIE CAS 2008年第4期308-308,共1页
关键词 Co Major Companies Producing large-sized Castings and Their Capacity in Consecutive Three Years
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Application of a Web Search Engine in Translating Business Terms in English-Chinese Dictionaries
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作者 HE Jianing ZHOU Zhiyi +2 位作者 XU Rong WU Minghui XIE Zijun 《Sino-US English Teaching》 2018年第9期454-458,共5页
Web search engines are important tools for lexicography.This paper takes translation of business terms("e-commerce"and"e-business")as an example to illustrate the application of web search engines ... Web search engines are important tools for lexicography.This paper takes translation of business terms("e-commerce"and"e-business")as an example to illustrate the application of web search engines in English-Chinese dictionary translation,including the methods of(1)finding the potential Chinese equivalents of the English business terms,and(2)selecting typical and proper Chinese equivalents in accordance with the frequencies and the meanings of the English business terms respectively. 展开更多
关键词 web search engine BUSINESS TERM ENGLISH-CHINESE DICTIONARY translation
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Scaffolding Information of Learner’s Dictionaries for L2 Writing: A User Perspective
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作者 YANG Na LI Yan ZHENG Jie 《Sino-US English Teaching》 2021年第3期51-59,共9页
As a major resource and tool of language learning, learner’s dictionaries have provided sufficient information forL2 writing, which serves as a good guide of peer feedback. Hence, learner’s dictionaries are an indis... As a major resource and tool of language learning, learner’s dictionaries have provided sufficient information forL2 writing, which serves as a good guide of peer feedback. Hence, learner’s dictionaries are an indispensable partof scaffolding in the L2 writing feedback system. However, the effects of dictionary use in L2 writing have longbeen ignored either in L2 writing pedagogy or in learner lexicography. By applying the concept of “scaffolding” topeer feedback as the theoretical framework, this study first clarifies three distinct types of scaffolding informationpresented in current English learner’s dictionaries, and then makes an investigation into EFL learners’ perceptionand practical use of scaffolding information in their English writing. Results show that most EFL learners havepositive attitudes towards scaffolding information and its role in motivating effective feedback in English writing.But their practical use of such information is not satisfactory owing to their inadequate skills and knowledge ofdictionary use. This reflects a high demand of a dictionary use course in universities, which will help to raise EFLlearners’ dictionary use efficiency as well as improve English teachers’ lexicographical expertise in English writingpedagogy. 展开更多
关键词 scaffolding information learner’s dictionaries peer feedback
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A Study on the Compilation of Dictionaries for Teaching Chinese as a Foreign Language Based on the Second Language Acquisition Theory
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作者 黄毓芸 《海外英语》 2016年第5期178-180,共3页
This article intends to demonstrate the principles for dictionary compilation.To summarize,general rules are to be followed.At the same time,this article probes into the differences of Chinese to Chinese dictionary,Ch... This article intends to demonstrate the principles for dictionary compilation.To summarize,general rules are to be followed.At the same time,this article probes into the differences of Chinese to Chinese dictionary,Chinese to foreign language dictionary,dictionaries for the preparation of certain exams,learner’s dictionaries for reviewing errors,dictionaries with multimedia and dictionaries built via the Internet..In all,one of the key factors for dictionary compilation is the professionalism of editors and writers.The training of the people involved is vital,which would contribute to setting up a better order of the market.Acknowledgements should also be given to achievements in dictionary compilation.Revisions and polishing are required to improve the dictionaries on the market that have already won the acclaim so as to put their influence to the best display. 展开更多
关键词 SECOND LANGUAGE ACQUISITION COMPILATION of dictionaries TEACHING Chinese as a FOREIGN LANGUAGE
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The first domesticated large-sized nuclear power plant was built up
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《Electricity》 2001年第4期52-52,共1页
关键词 The first domesticated large-sized nuclear power plant was built up
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A Polish College Students' Use of Dictionaries in Text Production
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作者 Dorota Osuchowska 《Sino-US English Teaching》 2014年第10期726-732,共7页
关键词 大学生 字典 制作 文本 波兰 语言学习 能力水平 表现能力
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Presenting Knowledge System of International Trade Terms in Business English Learners' Dictionaries
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作者 HE Jia-ning KHOU Zhi-yi +2 位作者 XIE Zi-jun WU Ming-hui XU Rong 《Journal of Literature and Art Studies》 2018年第8期1275-1281,共7页
关键词 商务英语 国际贸易 学习方法 语言学习
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Understanding media and electronic dictionaries
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作者 王新朋 《海外英语》 2012年第13期277-279,共3页
As the first father and leading prophet of the electronic age,Marshall McLuhan's media theory can present us a completely new approach towards the understanding of electronic dictionaries.In this paper,the author ... As the first father and leading prophet of the electronic age,Marshall McLuhan's media theory can present us a completely new approach towards the understanding of electronic dictionaries.In this paper,the author attempts to explore the interrelationship between major concepts of Marshall McLuhan's media theory and electronic dictionaries. 展开更多
关键词 Marshall MCLUHAN MEDIA THEORY ELECTRONIC dictionar
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基于数据挖掘的痛经用药规律研究 被引量:1
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作者 徐小港 王钰 +3 位作者 徐义峰 董辛 周聪慧 章德林 《西部中医药》 2024年第2期99-103,共5页
目的:基于数据挖掘技术分析《中医方剂大辞典》中治疗痛经方剂的用药规律。方法:根据纳入与排除标准筛选出《中医方剂大辞典》中治疗痛经的方剂,对其进行方药名称规范,运用Excel、IBM SPSS Modeler 18.0、IBM SPSS Statistics 26.0等进... 目的:基于数据挖掘技术分析《中医方剂大辞典》中治疗痛经方剂的用药规律。方法:根据纳入与排除标准筛选出《中医方剂大辞典》中治疗痛经的方剂,对其进行方药名称规范,运用Excel、IBM SPSS Modeler 18.0、IBM SPSS Statistics 26.0等进行频数统计、关联规则分析、聚类分析及因子分析。结果:共纳入151首治疗痛经的方剂,涉及中药191味;其中出现频次≥10的中药为当归、川芎、延胡索、白芍、香附、甘草等共36味,药效以补虚药、活血化瘀药、理气药为主,药性偏温、寒、平,药味则偏辛、苦、甘,多入肝、脾、心经。选取出现频次≥25的13味高频药物进行关联规则分析,得到“当归-川芎“”当归-香附-川芎“”当归-熟地黄-白芍-川芎”等常用药对21组,并通过提升关联规则的支持度得到“当归-川芎-白芍”核心组合。进行高频药物聚类分析得出4类药物组合,C1:白芍、熟地黄、川芎、当归;C2:牡丹皮、茯苓;C3:香附、甘草;C4:桃仁、红花,因子分析得到5个公因子。结论《:中医方剂大辞典》中治疗痛经以补血活血、化瘀散结、疏肝理气为主。 展开更多
关键词 痛经 数据挖掘 用药规律 中医方剂大辞典
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基于知识图谱的多特征融合谣言检测方法 被引量:1
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作者 刘小洋 李慧 +2 位作者 张康旗 段迪 文癸凌 《计算机应用研究》 CSCD 北大核心 2024年第5期1362-1367,共6页
为了解决谣言检测中由于缺乏外部知识而导致模型难以感知内隐信息,进而限制了模型挖掘深层信息的能力这个问题,提出了基于知识图谱的多特征融合谣言检测方法(KGMRD)。首先,对于每个事件,将帖子和评论共同构建为一个文本序列,并利用分类... 为了解决谣言检测中由于缺乏外部知识而导致模型难以感知内隐信息,进而限制了模型挖掘深层信息的能力这个问题,提出了基于知识图谱的多特征融合谣言检测方法(KGMRD)。首先,对于每个事件,将帖子和评论共同构建为一个文本序列,并利用分类器从中提取情感特征,利用ConceptNet基于文本构造其知识图谱,将知识图谱中的实体表示利用注意力机制与文本的语义特征进行聚合,进而得到增强的语义特征表示;其次,在传播结构方面,对于每个事件,基于帖子的传播转发关系构建传播结构图,使用DropEdge对传播结构图进行剪枝,从而得到更有效的传播结构特征;最后,将得到的特征进行融合处理得到一个新的表示。在Weibo、Twitter15和Twitter16三个真实数据集上,使用SVM-RBF等七个模型作为基线进行了对比实验。结果表明:对比当前效果最好的基线,KGMRD方法在Weibo数据集的ACC指标提升了1.1%;在Twitter15和Twitter16数据集的ACC指标上提升了2.2%,证明了KGMRD方法是合理的、有效的。 展开更多
关键词 知识图谱 注意力机制 情感词典 谣言检测
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压缩感知字典迁移重构的小样本轴承故障诊断
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作者 孙洁娣 赵彬集 +1 位作者 温江涛 时培明 《振动与冲击》 EI CSCD 北大核心 2024年第5期62-71,120,共11页
针对实际应用中智能轴承故障诊断面临标签样本严重不足的问题,提出一种结合压缩感知、字典学习和迁移的数据增强算法,用于小样本故障诊断研究。首先,利用源域标签数据通过小波包字典学习和优化方法生成特定源域字典,并得到共享表示系数... 针对实际应用中智能轴承故障诊断面临标签样本严重不足的问题,提出一种结合压缩感知、字典学习和迁移的数据增强算法,用于小样本故障诊断研究。首先,利用源域标签数据通过小波包字典学习和优化方法生成特定源域字典,并得到共享表示系数,获取故障内在信息;之后采用少量目标域信号微调共享表示系数,并更新源域字典生成迁移字典;最后通过共享表示系数和迁移字典生成大量具有目标域特征的新样本,实现数据增强。采用常用的深度故障诊断网络对该数据增强算法进行了诊断性能验证,结果表明该方法产生的信号具有故障的有效信息,用于模型训练和识别能够取得较好的诊断性能。该方法为小样本故障诊断问题提出了新的思路。 展开更多
关键词 轴承故障诊断 数据增强 压缩感知重构 字典迁移
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