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Roller Screw and Threaded Chain Speed Reducer: An Experimental Evaluation
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作者 Filiberto Gutiérrez 《Modern Mechanical Engineering》 2024年第1期1-11,共11页
We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuratio... We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuration lessens wear, increases load capacity, and improves efficiency. The threaded chain consists of nut-shaped links. This paper presents the results of tests carried out on a prototype with a reduction ratio of 46. 展开更多
关键词 Speed Reducer Inverted roller Screw Chain Drive Threaded Chain Drive
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Translation of Culture-loaded Words in The Golden Cangue under the Perspective of Reception Aesthetics
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作者 YU Xuan 《Journal of Literature and Art Studies》 2024年第6期468-473,共6页
Good translations play a very important role in cultural exchange.The idea of reception aesthetics think the reader as the center in translation process.This paper will study the translation of culture-loaded words fr... Good translations play a very important role in cultural exchange.The idea of reception aesthetics think the reader as the center in translation process.This paper will study the translation of culture-loaded words from the perspective of reception aesthetics.It is divided into five parts.The first part mainly introduces the background and theoretical foundation of this paper,the second part introduces the writer’s works,the third part gives examples to analyze the culture-loaded words appearing in The Golden Cangue,the fourth part gives examples of the translation methods,and the fifth part is the conclusion.It aims to provide a reference for the English translation of culture-loaded words. 展开更多
关键词 Culture-loaded words Reception Aesthetic The Golden Cangue Eileen Chang
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Research on new beneficiation process of low-grade magnesite using vertical roller mill 被引量:4
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作者 Chuang Li Chuan-yao Sun +3 位作者 Yu-lian Wang Ya-feng Fu Peng-yun Xu Wan-zhong Yin 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第4期432-442,共11页
We investigated whether the vertical roller mill can be efficiently used in the beneficiation of low-grade magnesite and whether it can improve upon the separation indices achieved by the ball mill.We conducted experi... We investigated whether the vertical roller mill can be efficiently used in the beneficiation of low-grade magnesite and whether it can improve upon the separation indices achieved by the ball mill.We conducted experiments involving the reverse flotation and positive flotation of low-grade magnesite to determine the optimum process parameters,and then performed closed-circuit beneficiation experiments using the vertical roller mill and ball mill.The results show that the optimum process parameters for the vertical roller mill are as follows:a grinding fineness of 81.6wt%of particles less than 0.074 mm,a dodecyl amine(DDA)dosage in magnesite reverse flotation of 100 g·t?1,and dosages of Na2CO3,(NaPO3)6,and NaOL in the positive flotation section of 1000,100,and 1000 g·t?1,respectively.Compared with the ball mill,the use of the vertical roller mill in the beneficiation of low-grade magnesite resulted in a 1.28%increase in the concentrate grade of MgO and a 5.88%increase in the recovery of MgO.The results of our causation mechanism analysis show that a higher specific surface area and greater surface roughness are the main reasons for the better flotation performance of particles ground by the vertical roller mill in the beneficiation of lowgrade magnesite. 展开更多
关键词 LOW-GRADE MAGNESITE vertical roller mill reverse FLOTATION positive FLOTATION NEW BENEFICIATION process
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Model Building of Backup Roller Diameter Effect Rate in 4-High Mill 被引量:1
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作者 JianzhongXU DianyaoGONG +2 位作者 XianghuaLIU GuodongWANG XiaolinZHAO 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第4期454-456,共3页
Software for calculating the strip profile in 4-high hot rolling mill was developed using influence coefficient method. Regularity of backup roller diameter effect rate was studied systematically using the software. T... Software for calculating the strip profile in 4-high hot rolling mill was developed using influence coefficient method. Regularity of backup roller diameter effect rate was studied systematically using the software. The results show that backup roller diameter effect rates decrease versus the increase of strip width, increase significantly versus the increase of backup roller diameter and obscurely increase versus the increase of reduction. The difference between backup roller diameter effect rate and it is reference value increases versus strip width increasing. When backup rollers diameter is set to be 1.64 m and strip width is 1.85 m, the error of strip profile calculated using the model of backup roller diameter effect rate reference value will be 3.55μm. Based on the results, reference values of roller diameter effect rate and six power polynomial fitting coefficients of modification coefficients were determined considering coherent parameters. The high precision model of backup roller diameter effect rate was established. When the model is used to predict strip profile, the accuracy is less than 5.0 μm. 展开更多
关键词 4-high mill Influence coefficient method Strip profile Hot rolling Backup roller diameter Effect rate
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Remaining Useful Life Prediction for a Roller in a Hot Strip Mill Based on Deep Recurrent Neural Networks 被引量:9
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作者 Ruihua Jiao Kaixiang Peng Jie Dong 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第7期1345-1354,共10页
Accurate estimation of the remaining useful life(RUL)and health state for rollers is of great significance to hot rolling production.It can provide decision support for roller management so as to improve the productiv... Accurate estimation of the remaining useful life(RUL)and health state for rollers is of great significance to hot rolling production.It can provide decision support for roller management so as to improve the productivity of the hot rolling process.In addition,the RUL prediction for rollers is helpful in transitioning from the current regular maintenance strategy to conditional-based maintenance.Therefore,a new method that can extract coarse-grained and fine-grained features from batch data to predict the RUL of the rollers is proposed in this paper.Firstly,a new deep learning network architecture based on recurrent neural networks that can make full use of the extracted coarsegrained fine-grained features to estimate the heath indicator(HI)is developed,where the HI is able to indicate the health state of the roller.Following that,a state-space model is constructed to describe the HI,and the probabilistic distribution of RUL can be estimated by extrapolating the HI degradation model to a predefined failure threshold.Finally,application to a hot strip mill is given to verify the effectiveness of the proposed methods using data collected from an industrial site,and the relatively low RMSE and MAE values demonstrate its advantages compared with some other popular deep learning methods. 展开更多
关键词 Hot strip mill prognostics and health management(PHM) recurrent neural network(RNN) remaining useful life(RUL) roller management.
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Grinding process within vertical roller mills: experiment and simulation 被引量:11
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作者 WANG Jian-huai CHEN Qing-ru +2 位作者 KUANG Ya-li LYNCH A j ZHUO Jin-wu 《Mining Science and Technology》 EI CAS 2009年第1期97-101,共5页
Based on screening analysis, laser size analysis, grindability and rigidity tests of samples collected on line from a cement and a power plant, a simulation of the grinding process in vertical roller mills was carried... Based on screening analysis, laser size analysis, grindability and rigidity tests of samples collected on line from a cement and a power plant, a simulation of the grinding process in vertical roller mills was carried out. The simulation calculation used a breakage function, B. The results indicate that the breakage function, B, and the selection function, S, in the form of a matrix, can be used to express the probability of the material breaking during the grinding process. This allows the size distribution of the product to be numerically estimated. The simulation results also show that the simulated size distribution curves fit the actual experimental product curves quite well. The model provides a good starting point for simulation of the grinding process. Further research is needed to determine the proper breakage function and the matrix value of the selection function. 展开更多
关键词 磨矿工程 直轴旋辊 磨矿机 磨矿技术
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Analysis of Dynamic Characteristics of Forced and Free Vibrations of Mill Roll System Based on Fractional Order Theory
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作者 Li Jiang Tao Wang Qingxue Huang 《Journal of Beijing Institute of Technology》 EI CAS 2023年第5期640-652,共13页
In this paper,the main researches are focused on the horizontal nonlinear vibration characteristics of roll systems for rolling mill,mainly including the study of forced vibration and free vibration of the roller.Firs... In this paper,the main researches are focused on the horizontal nonlinear vibration characteristics of roll systems for rolling mill,mainly including the study of forced vibration and free vibration of the roller.Firstly,the nonlinear damping parameters and nonlinear stiffness parameters within interface of the rolling mill are both considered,and a fractional-order differential term is also introduced to model the horizontal nonlinear vibration.Secondly,the averaging method is introduced to solve the forced vibration system of the mill roll system,and the amplitude-frequency characteristic curves of the system are obtained for different orders,external excitation amplitudes,stiffness and fractional order coefficients.Thirdly,the amplitude-frequency and phasefrequency characteristics of the free vibration of the mill roll system are investigated at different fractional orders.Then,the accuracy of the averaging method for solving the dynamic characteristics of the system is verified by numerical analysis,and the effect of the fractional differential term coefficients and order on the dynamic characteristics of the roll system are investigated.Finally,the time-frequency characteristics and phase-frequency characteristics of free vibration systems at different fractional orders are studied.The validity of the theoretical study is also verified through experiments. 展开更多
关键词 roller system FRACTIONAL-ORDER average method forced vibration free vibration
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Optimal Design of Tapered Roller Bearings Based on Multi⁃Physics Objectives Using Evolutionary Algorithms
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作者 Rajiv Tiwari Rahul M.P.Chandran 《Journal of Harbin Institute of Technology(New Series)》 CAS 2023年第1期73-84,共12页
Rolling element bearing is the most common machine element in rotating machinery.An extended life is among the foremost imperative standards in the optimal design of rolling element bearings,which confide on the fatig... Rolling element bearing is the most common machine element in rotating machinery.An extended life is among the foremost imperative standards in the optimal design of rolling element bearings,which confide on the fatigue failure,wear,and thermal conditions of bearings.To fill the gap,in the current work,all three objectives of a tapered roller bearing have been innovatively considered respectively,which are the dynamic capacity,elasto-hydrodynamic lubrication(EHL)minimum film⁃thickness,and maximum bearing temperature.These objective function formulations are presented,associated design variables are identified,and constraints are discussed.To solve complex non⁃linear constrained optimization formulations,a best⁃practice design procedure was investigated using the Artificial Bee Colony(ABC)algorithms.A sensitivity analysis of several geometric design variables was conducted to observe the difference in all three objectives.An excellent enhancement was found in the bearing designs that have been optimized as compared with bearing standards and previously published works.The present study will definitely add to the present experience based design followed in bearing industries to save time and obtain assessment of bearing performance before manufacturing.To verify the improvement,an experimental investigation is worthwhile conducting. 展开更多
关键词 dynamic capacity evolutionary algorithm optimum design tapered roller bearings TEMPERATURE tolerance analysis
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Discussion on Lightning Protection Design of "Feilongzaitian" Roller Coaster of Fangte in Zigong
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作者 Zhengdong ZHOU Wei LIN +3 位作者 Xi ZHAO Xiangping ZHOU Aisong SONG Bin WU 《Meteorological and Environmental Research》 CAS 2023年第4期56-58,62,共4页
The lightning protection design of "Feilongzaitian" roller coaster of Fangte in Zigong was discussed, and the lightning protection measures of "Feilongzaitian" roller coaster were analyzed from the... The lightning protection design of "Feilongzaitian" roller coaster of Fangte in Zigong was discussed, and the lightning protection measures of "Feilongzaitian" roller coaster were analyzed from the aspects of direct lightning protection, grounding and lightning electromagnetic impulse protection. 展开更多
关键词 roller coaster Lightning protection DESIGN
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自然语言处理领域中的词嵌入方法综述 被引量:2
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作者 曾骏 王子威 +2 位作者 于扬 文俊浩 高旻 《计算机科学与探索》 CSCD 北大核心 2024年第1期24-43,共20页
词嵌入作为自然语言处理任务的第一步,其目的是将输入的自然语言文本转换为模型可以处理的数值向量,即词向量,也称词的分布式表示。词向量作为自然语言处理任务的根基,是完成一切自然语言处理任务的前提。然而,国内外针对词嵌入方法的... 词嵌入作为自然语言处理任务的第一步,其目的是将输入的自然语言文本转换为模型可以处理的数值向量,即词向量,也称词的分布式表示。词向量作为自然语言处理任务的根基,是完成一切自然语言处理任务的前提。然而,国内外针对词嵌入方法的综述文献大多只关注于不同词嵌入方法本身的技术路线,而未能将词嵌入的前置分词方法以及词嵌入方法完整的演变趋势进行分析与概述。以word2vec模型和Transformer模型作为划分点,从生成的词向量是否能够动态地改变其内隐的语义信息来适配输入句子的整体语义这一角度,将词嵌入方法划分为静态词嵌入方法和动态词嵌入方法,并对此展开讨论。同时,针对词嵌入中的分词方法,包括整词切分和子词切分,进行了对比和分析;针对训练词向量所使用的语言模型,从概率语言模型到神经概率语言模型再到如今的深度上下文语言模型的演化,进行了详细列举和阐述;针对预训练语言模型时使用的训练策略进行了总结和探讨。最后,总结词向量质量的评估方法,分析词嵌入方法的当前现状并对其未来发展方向进行展望。 展开更多
关键词 词向量 词嵌入方法 自然语言处理 语言模型 分词 词向量评估
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Next Words Prediction and Sentence Completion in Bangla Language Using GRU-Based RNN on N-Gram Language Model
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作者 Afranul Hoque Busrat Jahan +3 位作者 Shaikat Chandra Paul Zinat Ara Zabu Rakhi Mondal Papeya Akter 《Journal of Data Analysis and Information Processing》 2023年第4期388-399,共12页
We use a lot of devices in our daily life to communicate with others. In this modern world, people use email, Facebook, Twitter, and many other social network sites for exchanging information. People lose their valuab... We use a lot of devices in our daily life to communicate with others. In this modern world, people use email, Facebook, Twitter, and many other social network sites for exchanging information. People lose their valuable time misspelling and retyping, and some people are not happy to type large sentences because they face unnecessary words or grammatical issues. So, for this reason, word predictive systems help to exchange textual information more quickly, easier, and comfortably for all people. These systems predict the next most probable words and give users to choose of the needed word from these suggested words. Word prediction can help the writer by predicting the next word and helping complete the sentence correctly. This research aims to forecast the most suitable next word to complete a sentence for any given context. In this research, we have worked on the Bangla language. We have presented a process that can expect the next maximum probable and proper words and suggest a complete sentence using predicted words. In this research, GRU-based RNN has been used on the N-gram dataset to develop the proposed model. We collected a large dataset using multiple sources in the Bangla language and also compared it to the other approaches that have been used such as LSTM, and Naive Bayes. But this suggested approach provides excellent exactness than others. Here, the Unigram model provides 88.22%, Bi-gram model is 99.24%, Tri-gram model is 97.69%, and 4-gram and 5-gram models provide 99.43% and 99.78% on average accurateness. We think that our proposed method profound impression on Bangla search engines. 展开更多
关键词 Bangla Language words Prediction Sentence Completion GRU RNN Corpus N-Gram
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Analysis of Vibrations of Roller of the Polymer Composite Coating Equipment on Stitches of Tarpaulin Materials
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作者 Shavkat Behbudov Anvar Djurayev +2 位作者 Juramirza Kayumov Urinboy Kuryozov Mehrinur Samadova 《Engineering(科研)》 2023年第10期709-719,共11页
The article presents a structural diagram and the principle of operation of the installation of a sewing machine for applying a polymer composition to the stitch lines of tarpaulin materials. The calculation schemes a... The article presents a structural diagram and the principle of operation of the installation of a sewing machine for applying a polymer composition to the stitch lines of tarpaulin materials. The calculation schemes and the mathematical model of oscillations of the axis of the composite roller during the application of the polymer composition along the lines of tarpaulin materials are presented. Based on the numerical solution of the problem, the regularities of roller oscillations are presented. The main parameters of the system are substantiated. 展开更多
关键词 Sewing Machine Device roller Polymer Composition Vibration RIGIDITY
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A Study on the English Translation of Culture-Loaded Words From the Perspective of Relevance-Theoretic Translation Theory-A Case Study of Yang Xianyi’s The True Story of Ah Q
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作者 ZHANG Jia-ni GAO Wencheng 《Sino-US English Teaching》 2023年第7期276-282,共7页
Culture-loaded words reveal the basic features of a country’s social life,customs and habits,religious beliefs,and so on.The meanings of culture-loaded words contain the profound cultural connotation of a country or ... Culture-loaded words reveal the basic features of a country’s social life,customs and habits,religious beliefs,and so on.The meanings of culture-loaded words contain the profound cultural connotation of a country or a nation.However,due to the influence of different cultures,the original author and the target readers lack a common cognitive context,which means they cannot successfully conduct a cultural communication.Therefore,correctly understanding and translating these culture-loaded words have become a major problem for translators in the translation process of literary works.Under the guidance of the dual ostensive-inferential model in relevance-theoretical translation theory,this paper,by emphasizing the importance of common cognitive context to a successful translation,analyzes the translation process of five categories of culture-loaded words and summarizes the translation strategies that can accurately convey the writing intention of the original author,which provides a new perspective for the translation of culture-loaded words. 展开更多
关键词 culture-loaded words ostensive-inferential view cognitive context
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The Translation Strategies of Chinese Reduplicated Words From a Skopos Theory Perspective
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作者 HUA Yicheng 《Sino-US English Teaching》 2023年第4期151-157,共7页
This paper explores the translation strategies for Chinese reduplication to English from the perspective of Skopos theory. Drawing on previous research on the semantic functions of reduplication, the paper analyzes th... This paper explores the translation strategies for Chinese reduplication to English from the perspective of Skopos theory. Drawing on previous research on the semantic functions of reduplication, the paper analyzes the three main types of semantic changes in Chinese reduplicated words: intensification of meaning, moderation of meaning, and addition of meaning. The paper then proposes different translation strategies for Chinese reduplication, including same-word repetition, near-synonym repetition, “have a try” form, “noun(pl.) + of” form, and “all”, “each”, and “every” pattern. Finally, the paper emphasizes the importance of understanding the intended communicative function of the reduplicated words and the need for flexible handling in order to achieve a natural translation with better readability. 展开更多
关键词 reduplicated words Skopos theory C-E translation
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Sora:从技术哲学到文艺学的思考(笔谈) 被引量:4
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作者 吴冠军 赵宪章 《文化艺术研究》 2024年第1期10-15,111,共7页
哲学学者吴冠军从技术哲学的视角提出:从ChatGPT、DALL·E到Sora,基于转化器的AIGC大模型并不只改变了内容创作,还改变了“世界”在最字面上的意义。世界化成的过程,越来越多被以有损压缩-重新生成为发生学机制的AIGC之创造性活动... 哲学学者吴冠军从技术哲学的视角提出:从ChatGPT、DALL·E到Sora,基于转化器的AIGC大模型并不只改变了内容创作,还改变了“世界”在最字面上的意义。世界化成的过程,越来越多被以有损压缩-重新生成为发生学机制的AIGC之创造性活动所介入,这就导致“宇宙”(我们眼里的“物理宇宙”)与“元宇宙”不断深层次地叠加,“自然进程”与“人工创造”不断深层次地交织以至进入无可区分之域。这就意味着,我们所熟悉的那个“世界”,将一去不复返:当AIGC已“深”到参与世界化成本身之中时,讨论“深伪”将越来越没有意义。文艺学学者赵宪章则从“语图关系学”的视角提出:Sora的横空出世及其未来演进,不仅不是图像时代符号危机的解除,更不是语图关系研究的终结。恰恰相反,Sora加深了这一危机,语图关系研究也延宕出新的面向。 展开更多
关键词 SORA 世界化成 元宇宙 语图关系
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A Study on German Translation Strategies of Culture-Loaded Words in Documentary Hexi Corridor(Expert)by Adaptation Theory
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作者 ZHU Yalin NI Xiaoshan 《Sino-US English Teaching》 2023年第2期74-79,共6页
This paper deals with the translation strategies of Chinese Culture-Loaded Words from the perspective of adaptation theory.It is based on the translation text of the sixth episode“Silk Road”and the seventh episode“... This paper deals with the translation strategies of Chinese Culture-Loaded Words from the perspective of adaptation theory.It is based on the translation text of the sixth episode“Silk Road”and the seventh episode“Dunhuang”of the documentary Hexi Corridor.Many words with Chinese cultural connotations appear in the subtitles of this documentary.This paper will be divided into four parts.The first part and the second part deal with the basic theories,i.e.,definition of Chinese Culture-Loaded Words and of adaptation theory.The original text is analysed in the third part.This part deals with the background and specifics of the language of the documentary film Hexi Corridor.The fourth part deals with the difficulties encountered by the author in translation practice and the corresponding solutions adopted by the author.The translation difficulties are solved by five translation methods,namely transliteration,loan translation,substitution,interpretation,and adaptation. 展开更多
关键词 Chinese Culture-Loaded words adaptation theory documentary film Hexi Corridor translation strategies and methods
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基于多头注意力机制字词联合的中文命名实体识别
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作者 王进 王猛旗 +2 位作者 张昕跃 孙开伟 朴昌浩 《江苏大学学报(自然科学版)》 CAS 北大核心 2024年第1期77-84,共8页
针对现有基于字词联合的中文命名实体识别方法会引入冗余词汇干扰、模型网络结构复杂、难以迁移的问题,提出一种基于多头注意力机制字词联合的中文命名实体识别算法.算法采用多头注意力机制融合词汇边界信息,并通过分类融合BIE词集降低... 针对现有基于字词联合的中文命名实体识别方法会引入冗余词汇干扰、模型网络结构复杂、难以迁移的问题,提出一种基于多头注意力机制字词联合的中文命名实体识别算法.算法采用多头注意力机制融合词汇边界信息,并通过分类融合BIE词集降低冗余词汇干扰.建立了多头注意力字词联合模型,包含字词匹配、多头注意力、融合等模块.与现有中文命名实体识别方法相比,本算法避免了设计复杂的序列模型,方便与现有基于字的中文命名实体识别模型结合.采用召回率、精确率以及F 1值作为评价指标,通过消融试验验证模型各个部分的效果.结果表明,本算法在MSRA和Weibo数据集上F 1值分别提升0.28、0.69,在Resume数据集上精确率提升0.07. 展开更多
关键词 中文命名实体识别 词汇冗余 词汇边界信息 字词联合 多头注意力机制 BIE词集
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阅读伴随词汇学习的词切分:首、尾词素位置概率的不同作用
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作者 梁菲菲 冯琳琳 +2 位作者 刘瑛 李馨 白学军 《心理学报》 CSCD 北大核心 2024年第3期281-294,共14页
本研究通过两个平行实验,探讨重复学习新词时首、尾词素位置概率信息作用于词切分的变化模式。采用阅读伴随词汇学习范式,将双字假词作为新词,实验1操纵首词素位置概率高低,保证尾词素相同;实验2操纵尾词素位置概率高低,保证首词素相同... 本研究通过两个平行实验,探讨重复学习新词时首、尾词素位置概率信息作用于词切分的变化模式。采用阅读伴随词汇学习范式,将双字假词作为新词,实验1操纵首词素位置概率高低,保证尾词素相同;实验2操纵尾词素位置概率高低,保证首词素相同。采用眼动仪记录大学生阅读时的眼动轨迹。结果显示:(1)首、尾词素位置概率信息的词切分作用随新词在阅读中学习次数的增加而逐步变小,表现出“熟悉性效应”。(2)首词素位置概率信息的“熟悉性效应”表现在回视路径时间、总注视次数两个相对晚期的眼动指标,而尾词素位置概率信息的“熟悉性效应”则从凝视时间开始,到回视路径时间,再持续到总注视时间。结果表明首、尾词素的位置概率信息均作用于阅读伴随词汇学习的词切分,但首词素的作用时程更长,更稳定,支持了首词素在双字词加工中具有优势的观点。 展开更多
关键词 词素位置概率 词切分 阅读伴随词汇学习 中文阅读
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对辊制粒机压辊的有限元分析及优化
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作者 李延民 蔡志源 +1 位作者 霍征征 刘国宁 《机械设计与制造》 北大核心 2024年第1期90-94,共5页
对辊制粒机的压辊在工作过程中由于受交变载荷作用寿命往往较短,为改善压辊受力状况,根据对对辊制粒机制粒成型过程的分析以及对压辊受力状况的研究,建立了压辊的力学模型;在此基础上,以某型对辊制粒机为初始模型,通过有限元软件Abaqus... 对辊制粒机的压辊在工作过程中由于受交变载荷作用寿命往往较短,为改善压辊受力状况,根据对对辊制粒机制粒成型过程的分析以及对压辊受力状况的研究,建立了压辊的力学模型;在此基础上,以某型对辊制粒机为初始模型,通过有限元软件Abaqus探究了压辊表面应力分布情况,并进一步对其长径比及支撑方式进行了优化,结果表明:压辊长径比为1.034时,最大应力比初始模型减小了8.92%,单侧支撑改为双侧支撑可使最大应力减小65.31%,因此这两种优化方式对提高压辊的使用寿命具有重要参考价值。 展开更多
关键词 对辊制粒机 压辊 模孔 长径比 有限元
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基于上下文词预测和窗口压缩编码的数字水印方法
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作者 向凌云 黄明豪 +1 位作者 张晨凌 杨春芳 《通信学报》 EI CSCD 北大核心 2024年第2期213-224,共12页
针对已有自然语言数字水印方法可替换词数量有限以及水印提取效率低的问题,提出了一种基于上下文词预测和窗口压缩编码的数字水印方法。该方法通过神经网络语言模型自动学习原始文本中每个词的上下文语义特征,预测每个词的候选词列表,... 针对已有自然语言数字水印方法可替换词数量有限以及水印提取效率低的问题,提出了一种基于上下文词预测和窗口压缩编码的数字水印方法。该方法通过神经网络语言模型自动学习原始文本中每个词的上下文语义特征,预测每个词的候选词列表,从而扩充可用于嵌入水印信息的可替换词数量。同时,考虑到不同位置的候选词的替换对句子语义的影响存在差异,该方法以由多个词组成的窗口为单位来嵌入水印信息,并通过词替换前后句子间的相似度来优化水印嵌入时候选词的选择。在此基础上,提出了一种语义无关的窗口压缩编码方法,其根据窗口中词的字符信息对窗口进行水印编码,解决了提取水印信息时对词替换位置的原始上下文的依赖。实验结果表明,所提方法在具有较高嵌入容量和文本质量的前提下,大大提高了水印的提取效率。 展开更多
关键词 数字水印 词替换 词预测 水印编码
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