Encoderless Five-phase PMa-SynRM Drive System Based on Robust Torque-speed Estimator with Super-twisting Sliding Mode Control

In this paper,a robust torque speed estimator(RTSE)for linear parameter changing(LPC)system is proposed and designed for an encoderless five-phase permanent magnet assisted synchronous reluctance motor(5-phase PMa-SynRM).This estimator is utilized for estimating the rotor speed and the load torque as well as can solve the speed sensor fault problem,as the feedback speed information is obtained directly from the virtual sensor.In addition,this technique is able to enhance the 5-phase PMa-SynRM performance by estimating the load torque for the real time compensation.The stability analysis of the proposed estimator is performed via Schur complement along with Lyapunov analysis.Furthermore,for improving the 5-phase PMa-SynRM performance,five super-twisting sliding mode controllers(ST-SMCs)are employed with providing a robust response without the impacts of high chattering problem.A super-twisting sliding mode speed controller(ST-SMSC)is employed for controlling the PMa-SynRM rotor speed,and four super-twisting sliding mode current controllers(ST-SMCCs)are employed for controlling the 5-phase PMa-SynRM currents.The stability analysis and the experimental results indicate the effectiveness along with feasibility of the proposed RTSE and the ST-SMSC with ST-SMCCs approach for a 750-W 5-phase PMa-SynRM under load disturbance,parameters variations,single open-phase fault,and adjacent two-phase open circuit fault conditions.

Exploring Nominalization in English Abstracts of Applied Linguistics Research Articles:A Comparative Study Between Chinese and International Journals

Researchers around the world strive to communicate new knowledge,primarily via publication,with the abstract being crucial in conveying core insights.Previous research has generally analyzed the discourse features of abstracts from a macro perspective and often employed either outdated texts,such as those over a decade old,or papers written by authors with lower English academic writing proficiency as research material.In this study,we analyzed forty abstracts from leading journals in applied linguistics,evenly split between Chinese and international journals.It revealed that the use of nominalization in abstracts by Chinese and international scholars showed similarities due to the universal academic requirement for conciseness.However,due to cultural and educational differences,each group differed in their respective language choices and nominalization usage.By analyzing the application of nominalization in different cultural contexts,the results of our study offered practical suggestions for crafting abstracts that effectively convey information,thereby,contributing to the broader academic community.

Embodied Meaning in Comprehending Abstract Chinese Counterfactuals

Embodied cognition theories propose that language comprehension triggers a sensorimotor system in the brain.However,most previous research has paid much attention to concrete and factual sentences,and little emphasis has been put on the research of abstract and counterfactual sentences.The primary challenges for embodied theories lie in elucidating the meanings of abstract and counterfactual sentences.The most prevalent explanation is that abstract and counterfactual sentences are grounded in the activation of a sensorimotor system,in exactly the same way as concrete and factual ones.The present research employed a dual-task experimental paradigm to investigate whether the embodied meaning is activated in comprehending action-related abstract Chinese counterfactual sentences through the presence or absence of action-sentence compatibility effect(ACE).Participants were instructed to read and listen to the action-related abstract Chinese factual or counterfactual sentences describing an abstract transfer word towards or away from them,and then move their fingers towards or away from them to press the buttons in the same direction as the motion cue of the transfer verb.The action-sentence compatibility effect was observed in both abstract factual and counterfactual sentences,in line with the embodied cognition theories,which indicated that the embodied meanings were activated in both action-related abstract factuals and counterfactuals.

A Comparative Analysis of Syntactic Complexity in Applied Linguistics Abstracts Written by Chinese Novice Writers and Native English Advanced Writers

The rhetorical structure of abstracts has been a widely discussed topic, as it can greatly enhance the abstract writing skills of second-language writers. This study aims to provide guidance on the syntactic features that L2 learners can employ, as well as suggest which features they should focus on in English academic writing. To achieve this, all samples were analyzed for rhetorical moves using Hyland’s five-rhetorical move model. Additionally, all sentences were evaluated for syntactic complexity, considering measures such as global, clausal and phrasal complexity. The findings reveal that expert writers exhibit a more balanced use of syntactic complexity across moves, effectively fulfilling the rhetorical objectives of abstracts. On the other hand, MA students tend to rely excessively on embedded structures and dependent clauses in an attempt to increase complexity. The implications of these findings for academic writing research, pedagogy, and assessment are thoroughly discussed.

Performance Analysis and Comparison of Two Fault-Tolerant Model Predictive Control Methods for Five-Phase PMSM Drives

Model predictive current control(MPCC)and model predictive torque control(MPTC)are two derivatives of model predictive control.These two control methods have demonstrated their strengths in the fault-tolerant control of multiphase motor drives.To explore the inherent link,the pros and cons of two strategies,the performance analysis and comparative investigation of MPCC and MPTC are conducted through a five-phase permanent magnet synchronous motor with open-phase fault.In MPCC,the currents of fundamental and harmonic subspaces are simultaneously employed and constrained for a combined regulation of the open-circuit fault drive.In MPTC,apart from the torque and the stator flux related to fundamental subspace,the x-y currents are also considered and predicted to achieve the control of harmonic subspace.The principles of two methods are demonstrated in detail and the link is explored in terms of the cost function.Besides,the performance by two methods is experimentally assessed in terms of steady-state,transition,and dynamic tests.Finally,the advantages and disadvantages of each method are concluded.

Fault-Tolerant Operation of Five-Phase Permanent Magnet Synchronous Motor with Independent Phase Driving Control

The multi-phase motor drive system with multiple H-bridge power supply has high fault tolerance,which is widely used in aerospace,electric vehicle,ship integrated power system and other fields.In this paper,a fault-tolerant control strategy based on decoupling control and stator current compensation is proposed for the propulsion system of five-phase PMSM with independent neutrals.Firstly,the mathematical model of PMSM is established by using vector space decoupling method;Secondly,a stator current compensation method is adopted to carry out fault-tolerant control after the motor has single-phase and two-phase open-circuit faults and the fault-tolerant control system based on decoupling control is established;Finally,the decoupling control model and the fault-tolerant control of stator current compensation are verified by the simulation and experiment.The simulation and experiment results show that the method can reduce the torque ripple caused by the stator winding open-circuit fault,and the operation performance of the motor under fault condition is significantly improved.

Comparative Study on Torque Performance of Five-phase Single-Stator and Double-Stator Permanent Magnet Synchronous Motors

This paper compares the torque characteristics of single stator permanent magnet synchronous motor(PMSM)and double-stator PMSM under different split-ratios,air-gap lengths and shaft diameters by finite element method.Firstly,the effects of split-ratio towards the torque characteristics of the two motor structures under different air-gap lengths are researched,the results show that the optimal split-ratios of the two motor structures do not change under different air-gap lengths,and the optimal split-ratio of the double-stator motor is greater than that of single-stator,and the torque of the double-stator motor is greater than that of single-stator motor with arbitrary split-ratio under the same air-gap length;Finally,the effects of the shaft diameter to the torque of the two motor structures are investigated,obtaining that with the increasing of shaft diameter,the electromagnetic torque of the single-stator motor is almost unchanged,however,the torque of the double-stator is gradually reduced,when the shaft diameter reached a certain extent,the electromagnetic torque of the double-stator motor is smaller than that of single-stator motor with the split ratio within a certain range,and the torque/quality ratio of the double-stator motor is smaller than that of single-stator motor with their optimal split ratio separately.

Analysis of Direct Torque Control for Marine Five-Phase Induction Motor

Based on the principle of direct torque control,a DTC(Direct Torque Control)system with five-phase induction motor has been studied.Providing direct control of stator flux and electromagnetic torque by optimized voltage vector,five-phase induction motor enhances flexibility of the invert states selection by increasing the number of voltage vectors,resulting in more precise control of stator flux and electromagnetic torque.The model of DTC for five-phase induction motor is constructed on equations and the method of approximate circle of torque track is used to conduct the simulation analysis of the system.The simulation results demonstrate that the DTC for five-phase induction motor control has merits of little calculation compared with vector control,simple structure,fast response and greater dynamic performance.

Weakly Supervised Abstractive Summarization with Enhancing Factual Consistency for Chinese Complaint Reports

A large variety of complaint reports reflect subjective information expressed by citizens.A key challenge of text summarization for complaint reports is to ensure the factual consistency of generated summary.Therefore,in this paper,a simple and weakly supervised framework considering factual consistency is proposed to generate a summary of city-based complaint reports without pre-labeled sentences/words.Furthermore,it considers the importance of entity in complaint reports to ensure factual consistency of summary.Experimental results on the customer review datasets(Yelp and Amazon)and complaint report dataset(complaint reports of Shenyang in China)show that the proposed framework outperforms state-of-the-art approaches in ROUGE scores and human evaluation.It unveils the effectiveness of our approach to helping in dealing with complaint reports.

Novel multi‐domain attention for abstractive summarisation

The existing abstractive text summarisation models only consider the word sequence correlations between the source document and the reference summary,and the summary generated by models lacks the cover of the subject of source document due to models'small perspective.In order to make up these disadvantages,a multi‐domain attention pointer(MDA‐Pointer)abstractive summarisation model is proposed in this work.First,the model uses bidirectional long short‐term memory to encode,respectively,the word and sentence sequence of source document for obtaining the semantic representations at word and sentence level.Furthermore,the multi‐domain attention mechanism between the semantic representations and the summary word is established,and the proposed model can generate summary words under the proposed attention mechanism based on the words and sen-tences.Then,the words are extracted from the vocabulary or the original word sequences through the pointer network to form the summary,and the coverage mechanism is introduced,respectively,into word and sentence level to reduce the redundancy of sum-mary content.Finally,experiment validation is conducted on CNN/Daily Mail dataset.ROUGE evaluation indexes of the model without and with the coverage mechanism are improved respectively,and the results verify the validation of model proposed by this paper.

Abstraction and Representation:Form and Meaning in the Philosophy of Images

This article examines the complex interplay between abstraction and representation in the ontology of images.Images inhabit an in-between space as tangible artifacts that also convey intangible ideas and meanings.The analysis synthesizes perspectives from across the history of philosophy to elucidate how images bridge abstraction and representation through their form and function.It engages with ongoing epistemological and aesthetic debates concerning the dual nature of images.Plato’s theory of ideal forms is outlined as an early attempt to define abstraction.Modern semiotic theories are discussed for their insights into how images create meaning through codes and signs.Phenomenology offers an alternative approach by prioritizing the sensorial,affective impact of images.Poststructuralism problematizes representation in the context of mechanical reproduction and simulacra.While diverse,these philosophical frameworks all grapple with the issues images pose between abstract essence and concrete appearance,conceptual ideas and sensory manifestations.The article reveals the richness of images as liminal constructs that collapse dualisms in their creative interfacing of material forms and immaterial meanings.It concludes that this ontological ambiguity empowers images as mediators between imagination and perception,subjectivity and reality.

A Method of Integrating Length Constraints into Encoder-Decoder Transformer for Abstractive Text Summarization

Text summarization aims to generate a concise version of the original text.The longer the summary text is,themore detailed it will be fromthe original text,and this depends on the intended use.Therefore,the problem of generating summary texts with desired lengths is a vital task to put the research into practice.To solve this problem,in this paper,we propose a new method to integrate the desired length of the summarized text into the encoder-decoder model for the abstractive text summarization problem.This length parameter is integrated into the encoding phase at each self-attention step and the decoding process by preserving the remaining length for calculating headattention in the generation process and using it as length embeddings added to theword embeddings.We conducted experiments for the proposed model on the two data sets,Cable News Network(CNN)Daily and NEWSROOM,with different desired output lengths.The obtained results show the proposed model’s effectiveness compared with related studies.

Analysis of Common Mistakes in English Abstract Writing of Scientific and Technological Papers:A Case Study of Automotive Practical Technology

Abstract is the epitome of the core idea of a journal paper.Excellent English abstract plays an important role in ensuring the quality of the paper and promoting its academic value in international exchanges.However,there are still many problems in the English abstracts of many papers published in academic journals.This paper analyzes and summarizes the grammatical errors of articles,singular and plural nouns,predicate verbs,conjunctions,Chinglish from other English abstracts of some papers in a vehicle engineering academic journal retrieved from CNCN.cn,and then corrects them.It is expected to provide some guidance for editors,academic workers,and engineering students in writing papers.

竞技运动专家的认知优势及其形成机制——基于自动性特点和抽象化表征

目前对于竞技运动专家如何从长期训练中获得和迁移、提炼和更新专业知识与技能的机制尚未有清晰的阐释。基于专家-新手范式的研究表明,从表征学习的角度看竞技运动专家的认知优势主要体现在注意优势和记忆优势两方面,而竞技运动专家知识与技能的自动性特点和抽象化表征是其认知优势效应形成的两个关键原因。从生成模型的角度探讨竞技运动专家知识系统的抽象化表征机制,为能更好地理解竞技运动专家的认知优势效应,助其突破认知局限性提供了新的理论依据。

数学教学视域下理解与应用皮亚杰建构主义理论

建构主义是皮亚杰发生认识论的核心,同时也是现代建构主义教学的主要理论基础,对建构主义教学思想的发展和国际教育改革均产生了重要影响.其理论从心理学的角度阐述了有变化的“重复”能够促进认知的发展,能够有效地促进学生的数学学习.在阐述平衡机制、反省抽象等相关内容的基础上,研究得出反省抽象范畴之间的关系框架图、在数学教学中的应用路径,以及皮亚杰建构主义理论对当下数学教学的启示:数学教学应关注过程教育、数学教学过程中应把经验抽象与反省抽象有机结合、数学抽象思维教学应遵循思维发展的阶段性、数学教学应重视学生批判性思维能力的培养.

抽象空间的矛盾与差异——列斐伏尔《空间的生产》解读

在资本主义抽象空间的发展中,越来越多的内在冲突和矛盾暴露出来,这需要一种面对抽象空间生产中的矛盾分析。重新颠倒被资本主义颠倒了的抽象空间,关键在于要深刻把握这一空间生产中社会基本矛盾中的新动向。要真正战胜资本主义空间生产方式,空间理论就必须重新关注在抽象空间的生产中被遮蔽起来的差异性,它将是原有空间生产体系本身自我爆炸的裂口,这也意味着,在社会空间生产中,探寻社会矛盾中发生的最大差异化则是走向新空间生产的开端。

师范院校本科抽象代数课程的创新与实践

抽象代数是综合性大学和师范院校数学专业最重要的专业基础课程,对于培养学生的抽象思维、代数结构化思维和创新能力有重要意义.论文介绍了综合院校和师范院校数学系抽象代数课程的历史以及与中学数学的联系,阐述了目前的教学现状及面临的挑战,深入分析了抽象代数课程的特点以及师范院校针对课程的材料的选取.最后介绍了近年来作者在华中师范大学对于该课程教学所作的若干创新与实践.

数学基本思想在集合教学中的运用

为帮助学生全面深入地理解集合概念,对数学基本思想在集合教学中的运用进行了研究。数学基本思想一般包括抽象、推理与模型,教师从集合概念的抽象性、集合关系的抽象性出发,引导学生理解数学抽象思想;从集合推理运算的基础、集合恒等式的推理与证明出发,引导学生理解数学推理思想;从计数与概率论、数理逻辑中的集合模型出发,引导学生理解数学模型思想。

《资本论》的时间辩证法:资本逻辑的时间叙事及其解放

《资本论》的时间概念与资本批判紧密相连。马克思在该书中分析指出,时间在资本的作用下呈现出具体和抽象的二重性质。具体时间与个体的社会劳动结合在一起,抽象时间则表现为价值的独立运动。资本周转与时间转化交织浸润,资本逻辑的建构体现为从具体转化为抽象的时间规范。作为一种将时间抽象化的强制力量,资本将个体的生命时间统摄于它的结构之内,这导致劳动者无可规避地处于被奴役和支配的异化状态。除了建构时间的抽象统治结构,资本主义还造就了一种瓦解资本逻辑的历史动力——从抽象还原到具体的自由时间。资本增殖的空间来源于劳动者被压缩的可支配的自由时间,只有对资本的批判“代表一个阶级”,劳动者才能真正推翻时间的抽象统治。要完全超越资本,必须要在整个社会范围内解放自由时间。只有在社会主义社会中,时间才能从异化劳动的空间转化为自由发展的空间。马克思在《资本论》中的上述分析,不仅解开了“资本之谜”,也解开了“时间之谜”和“自由之谜”,在揭示资本逻辑限度的同时,为当代社会主义世界中人的自由解放指明了方向。

体型参数对梯形旋流排沙渠道水力特性的影响

为明确起旋室和排沙洞体型参数对梯形旋流排沙渠道水力特性的影响,采用试验研究与数值模拟相结合的方法,研究了各参数下旋流排沙渠道的分流比、空腔形态、压强、流速,对比分析了不同断面型式的水力特性。结果表明,增大起旋室进口宽度,或减小起旋室出口宽度、起旋室高度、排沙洞直径,均能减小梯形旋流排沙渠道的分流比;起旋室出口宽度是影响分流比的主要因素,排沙洞直径偏小会限制排沙洞内空腔的发展;增加渠道水面与排沙洞出口间的落差后可在排沙洞内形成更有利于泥沙运动的旋转水流;梯形旋流排沙渠道的水资源利用效率更高,当渠道来流量为89.6 m^(3)/h时,梯形旋流排沙渠道的分流比较矩形渠道的降低了6.6个百分点,且同一位置处的旋转水流流速更大。研究成果可为旋流排沙渠道在引水工程中的设计与应用提供参考。