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Fault diagnosis of bearings based on deep separable convolutional neural network and spatial dropout

Chinese Journal of Aeronautics 2022年第10期35卷 301-312页

作者： Jiqiang ZHANG xiangwei kong Xueyi LI Zhiyong HU Liu CHENG Mingzhu YU School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of EducationNortheastern UniversityShenyang 110819China Liaoning Province Key Laboratory of Multidisciplinary Design Optimization of Complex Equipment Northeastern UniversityShenyang 110819China Angang Steel Company Limited Anshan 114021China

Bearing pitting,one of the common faults in mechanical systems,is a research hotspot in both academia and industry.Traditional fault diagnosis methods for bearings are based on manual experience with low diagnostic efficiency.This study proposes a novel bearing fault diagnosis method based on deep separable convolution and spatial dropout regularization.Deep separable convolution extracts features from the raw bearing vibration signals,during which a 3×1 convolutional kernel with a one-step size selects effective features by adjusting its weights.The similarity pruning process of the channel convolution and point convolution can reduce the number of parameters and calculation quantities by evaluating the size of the weights and removing the feature maps of smaller weights.The spatial dropout regularization method focuses on bearing signal fault features,improving the independence between the bearing signal features and enhancing the robustness of the model.A batch normalization algorithm is added to the convolutional layer for gradient explosion control and network stability improvement.To validate the effectiveness of the proposed method,we collect raw vibration signals from bearings in eight different health states.The experimental results show that the proposed method can effectively distinguish different pitting faults in the bearings with a better accuracy than that of other typical deep learning methods.

关键词： Batch normalization Convolutional neural network Fault diagnosis Similarity pruning Spatial dropout

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Continuous Cooling Bainite Transformation Characteristics of a Low Carbon Microalloyed Steel under the Simulated Welding Thermal Cycle Process

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Journal of Materials Science & Technology 2013年第5期29卷 446-450页

作者： xiangwei kong Chunlin Qiu School of Mechanical Engineering and Automation Northeastern University State Key Laboratory of Rolling Technology and Automation Northeastern University

Continuous cooling transformation of a low carbon microalloyed steel was investigated after it was subjected to the simulation welding thermal cycle process and the interrupted cooling test. Microstructure observation was performed by optical microscopy and transmission electron microscopy. On the basis of the dilatometric data and microstructure observation, the continuous cooling transformation （CCT） diagram was determined, which showed that the main microstructure changes from a mixture of lath martensite and bainitic ferrite to full granular bainite with the increase in the cooling time t8/5 from 10 to 600 s, accompanied with a decrease in the microhardness. The interrupted cooling test confirmed that the bainitic ferrite can form attached to grain boundaries at the beginning of transformation even if the final microstructure contains a mixture of granular bainite and bainitic ferrite.

关键词： Low carbon microanoyed steel Bainitic ferrite Continuous cooling transformation Welding

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Contextual modeling on auxiliary points for robust image reranking

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Frontiers of Computer Science 2019年第5期13卷 1010-1022页

作者： Ying LI xiangwei kong Haiyan FU Qi TIAN School of Information and Communication Engineering Dalian University of Technology Dalian 116024 China Department of Computer Science University of Texas at San Antonio Texas 78249 USA

Image reranking is an effective post-processing step to adjust the similarity order in image retrieval. As key components of initialized ranking lists, top-ranked neighborhoods of a given query usually play important roles in constructing dissimilarity measure. However, the number of pertinent candidates varies with respect to different queries. Thus the images with short lists of ground truth suffer from insufficient contextual information. It consequently introduces noises when using k-nearest neighbor rule to define the context. In order to alleviate this problem, this paper proposes auxiliary points which are added as assistant neighbors in an unsupervised manner. These extra points act on revealing implicit similarity in the metric space and clustering matched image pairs. By isometrically embedding each constructed metric space into the Euclidean space, the image relationships on underlying topological manifolds are locally represented by distance descriptions. Furthermore, by combining Jaccard index with our auxiliary points, we present a contextual modeling on auxiliary points ( CMAP ) method for image reranking. With richer contextual activations, the Jaccard similarity coefficient defined by local distribution achieves more reliable outputs as well as more stable parameters. Extensive experiments demonstrate the robustness and effectiveness of the proposed method.

关键词： image retrieval unsupervised reranking context construction Jaccard distance query expansion

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INS-GNSS Integrated Navigation Algorithm Based on TransGAN

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Intelligent Automation & Soft Computing 2023年第7期37卷 91-110页

作者： Wang Linxuan Kong Xiangwei Xu Hongzhe Li Hong Chinese Flight Test Establishment Xi’an710089China Xi’an Jiaotong University Xi’an710049China

With the rapid development of autopilot technology,a variety of engi-neering applications require higher and higher requirements for navigation and positioning accuracy,as well as the error range should reach centimeter level.Single navigation systems such as the inertial navigation system(INS)and the global navigation satellite system(GNSS)cannot meet the navigation require-ments in many cases of high mobility and complex environments.For the purpose of improving the accuracy of INS-GNSS integrated navigation system,an INS-GNSS integrated navigation algorithm based on TransGAN is proposed.First of all,the GNSS data in the actual test process is applied to establish the data set.Secondly,the generator and discriminator are constructed.Borrowing the model structure of generator transformer,the generator is constructed by multi-layer transformer encoder,which can obtain a wider data perception ability.The generator and discriminator are trained and optimized by the production countermeasure network,so as to realize the speed and position error compensa-tion of INS.Consequently,when GNSS works normally,TransGAN is trained into a high-precision prediction model using INS-GNSS data.The trained Trans-GAN model is emoloyed to compensate the speed and position errors for INS.Through the test analysis ofﬂight test data,the test results are compared with the performance of traditional multi-layer perceptron(MLP)and fuzzy wavelet neural network(WNN),demonstrating that TransGAN can effectively correct the speed and position information when GNSS is interrupted,with the high accuracy.

关键词： GNSS INS TransGAN integrated navigation

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Evaluation of the Air Leakage Flowrate in Sintering Processes

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Fluid Dynamics & Materials Processing 2023年第11期19卷 2791-2812页

作者： Jin Cai xiangwei kong Mingzhu Yu School of Mechanical Engineering and Automation Northeastern UniversityShenyang110819China Anshan Iron&Steel Corp. Anshan114051China

Iron ore sintering is a pre-treatment technology by which orefines are converted into porous and permeable sin-ters,which are the used in blast furnaces.This process can be adversely affected by air leakage phenomena of various types.As experimental measurements are relatively difficult and often scarcely reliable,here a theoretical model based on typicalfluid-dynamic concepts and relationships is elaborated.Through the analysis of two extreme cases,namely,those in which leakage is due to a small hole or a full rupture,a generalized hole-bed mod-el is introduced,which for thefirst time also includes a complete bed permeability equation and can deal with different leakage position conditions.The results show that the model can evaluate the influence of leakage on the system at one time and be used to calculate theflowrate and pressure drop.Notably,the obtained results are within a 15%deviation with respect to available experiment values,used for comparison.

关键词： Sintering air leakage flowrate bed permeability different leakage positions

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Broaching Performance of Superalloy GH4169 Based on FEM

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Journal of Materials Science & Technology 2011年第12期27卷 1178-1184页

作者： xiangwei kong Bin Li Zhibo Jin Wenran Geng. School-of Mechanical Engineering ＆ Automation Northeastern University Shenyang 110004 China

The nickel-based superalloy GH4169 is an important material for high temperature applications in the aerospace industry. However, due to its poor machinability, GH416g is hard to be cut and generates saw-tooth chips during high speed machining, which could significantly affect the dynamic cutting force, cutting temperature fluctuation, tool life, and the surface integrity of the parts. In this paper, the saw-tooth chip formation mechanism of superalloy GH4169 was investigated by the elasto-viscoplastic finite element method （FEM）. Using the finite element software of ABAQUS/Explicit, the deformation of the part during high speed machining was simulated. The effective plastic strain, the temperature field, the stress distribution, and the cutting force were analyzed to determine the influence of the cutting parameters on the saw-tooth chip formation. The study on broaching performance has great effect on selecting suitable machining parameters and improving tool life.

关键词： Machining Superalloy Saw-tooth chip Finite element method （FEM）

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导向创新思维能力培养的命题研究

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物理通报 2024年第6期 129-132页

作者：孔祥伟广州市白云区教育研究院广东广州510440

创新思维能力有别于逻辑思维能力.表现在学生在陌生情境下善于发现问题,思维过程的独特性、灵活性和批判性是其明显特征;或在旧情境表现出思维的发散性,通过联想与顿悟,而使问题得以解决.

关键词：创新思维能力命题研究评价

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刑事涉案财物保管问题刍议

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保定学院学报 2022年第4期35卷 43-47页

作者：孔祥伟汕头大学法学院广东汕头515063

公安司法机关基于刑事诉讼的需要对涉案财物实施审前查控,由此,在国家与刑事诉讼当事人之间产生了公法上的保管关系,办案机关必须善尽保管之责任。由于我国《刑事诉讼法》并未对涉案财物保管问题作出详细规定,迄今为止,有关刑事涉案财... 详细信息

公安司法机关基于刑事诉讼的需要对涉案财物实施审前查控,由此,在国家与刑事诉讼当事人之间产生了公法上的保管关系,办案机关必须善尽保管之责任。由于我国《刑事诉讼法》并未对涉案财物保管问题作出详细规定,迄今为止,有关刑事涉案财物保管的具体规则主要集中在公安、检察机关制定的规范性文件中。目前,刑事涉案财物保管活动主要存在着三方面问题:一是现有规定侧重取证合法,忽视妥当保管;二是保管人员、保管机构专业化、专职化水平有待提高;三是涉案财物移送机制尚需进一步健全。未来,在制度设计层面上,刑事涉案财物保管制度改革应当从保管机构的统一化与专门化、探索信息化的涉案财物管理方式和适时引入涉案财物经营增值机制等角度着手。

关键词：刑事涉案财物涉案财物管理中心犯罪资产接管

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刑事司法中的未成年被害人保护:现状、特征与探索

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河北青年管理干部学院学报 2022年第2期34卷 78-84页

作者：孔祥伟汕头大学法学院广东汕头515063

即使是在公民权利保障较为充分的现代社会,未成年人依旧属于纯粹意义上的弱势群体。虽然近年来党和政府高度重视未成年人保护工作,预防、治理未成年人犯罪、救助未成年被害人的力度不断加大,一系列法律法规、专门性司法解释、指导案例... 详细信息

即使是在公民权利保障较为充分的现代社会,未成年人依旧属于纯粹意义上的弱势群体。虽然近年来党和政府高度重视未成年人保护工作,预防、治理未成年人犯罪、救助未成年被害人的力度不断加大,一系列法律法规、专门性司法解释、指导案例和典型案例相继颁布,但数据显示,侵害未成年人犯罪案件在全国多数地区仍呈上升趋势,个别地方涨幅较大。与普通刑事案件相比,侵害未成年人犯罪案件具有鲜明的特点。在全面总结侵害未成年人犯罪案件特征、规律的基础上,各地公安司法机关积极探索、勇于尝试、多措并举,为综合治理侵害未成年人犯罪积累了有益的经验。

关键词：未成年被害人司法保护强制报告一站式取证

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Application of Instantaneous Rotational Speed to Detect Gearbox Faults Based on Double Encoders

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Chinese Journal of Mechanical Engineering 2019年第1期32卷 54-64页

作者： Lin Liang Fei Liu xiangwei kong Maolin Li Guanghua Xu School of Mechanical Engineering Xi’an Jiaotong University Key Laboratory of Education Ministry for Modern Design and Rotor-bearing System Xi’an Jiaotong University Engineering Workshop Xi’an Jiaotong University State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong University

Considerable studies have been carried out on fault diagnosis of gears, with most of them concentrated on conventional vibration analysis. However, besides the complexity of gear dynamics, the diagnosis results in terms of vibration signal are easily misjudged owing to the interference of sensor position or other components. In this paper, an alternative gearbox fault detection method based on the instantaneous rotational speed is proposed because of its advantages over vibration analysis. Depending on the timer/counter-based method for the pulse signal of the optical encoder, the varying rotational speed can be obtained e ectively. Owing to the coupling and meshing of gears in transmission, the excitations are the same for the instantaneous rotational speed of the input and output shafts. Thus, the di erential signal of instantaneous rotational speeds can be adopted to eliminate the e ect of the interference excitations and extract the associated feature of the localized fault e ectively. With the experiments on multistage gearbox test system, the di erential signal of instantaneous speeds is compared with other signals. It is proved that localized faults in the gearbox generate small angular speed fluctuations, which are measurable with an optical encoder. Using the di erential signal of instantaneous speeds, the fault characteristics are extracted in the spectrum where the deterministic frequency component and its harmonics corresponding to crack fault characteristics are displayed clearly.

关键词： Instantaneous rotational speed Optical encoder Localized fault Multistage gearbox

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