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Chinese Journal of Aeronautics 2024年第9期37卷 506-520页

作者： jianyu wang Heng ZHANG Qiang MIAO College of Electrical Engineering Sichuan UniversityChengdu 610065China

Health monitoring of electro-mechanical actuator(EMA)is critical to ensure the security of *** is difficult or even impossible to collect enough labeled failure or degradation data from actual *** autoencoder based on reconstruction loss is a popular model that can carry out anomaly detection with only consideration of normal training data,while it fails to capture spatio-temporal information from multivariate time series signals of multiple monitoring *** mine the spatio-temporal information from multivariate time series signals,this paper proposes an attention graph stacked autoencoder for EMA anomaly ***,attention graph con-volution is introduced into autoencoder to convolve temporal information from neighbor features to current features based on different weight ***,stacked autoencoder is applied to mine spatial information from those new aggregated temporal ***,based on the bench-mark reconstruction loss of normal training data,different health thresholds calculated by several statistic indicators can carry out anomaly detection for new testing *** comparison with tra-ditional stacked autoencoder,the proposed model could obtain higher fault detection rate and lower false alarm rate in EMA anomaly detection experiment.

关键词： Anomaly detection Spatio-temporal informa-tion Multivariate time series signals Attention graph convolution Stacked autoencoder

Source free unsupervised domain adaptation for electro-mechanical actuator fault diagnosis

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Chinese Journal of Aeronautics 2023年第4期36卷 252-267页

作者： jianyu wang Heng ZHANG Qiang MIAO College of Electrical Engineering Sichuan UniversityChengdu 610065China

A common necessity for prior unsupervised domain adaptation methods that can improve the domain adaptation in unlabeled target domain dataset is access to source domain data-set and target domain dataset ***,data privacy makes it not always possible to access source domain dataset and target domain dataset in actual industrial equipment simulta-neously,especially for aviation component like Electro-Mechanical Actuator(EMA)whose dataset are often not shareable due to the data copyright and *** address this problem,this paper proposes a source free unsupervised domain adaptation framework for EMA fault *** proposed framework is a combination of feature network and ***,source domain datasets are only applied to train a source ***,the well-trained source model is trans-ferred to target domain and classifier is frozen based on source domain ***,nearest centroid filtering is introduced to filter the reliable pseudo labels for unlabeled target domain data-set,and finally,supervised learning and pseudo label clustering are applied to fine-tune the trans-ferred *** comparison with several traditional unsupervised domain adaptation methods,case studies based on low-and high-frequency monitoring signals on EMA indicate the effectiveness of the proposed method.

关键词： Data privacy Electro-mechanical actuator Pseudo-label clustering Nearest centroid filtering Unsupervised domain adaptation

Heterogeneous Quality of Experience Guarantees Over Wireless Networks

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China Communications 2018年第10期15卷 51-59页

作者： jianyu wang Wenchi Cheng State Key Laboratory of Integrated Services Networks Xidian University

Quality of experience(Qo E), which is very critical for the experience of users in wireless networks, has been extensively studied. However, due to different human perceptions, quantifying the effective capacity of wireless network subject to diverse Qo E is very difficult, which leads to many new challenges regarding Qo E guarantees in wireless networks. In this paper, we formulate the Qo E guarantees model for cellular wireless networks. Based on the model, we convert the effective capacity maximization problem into the equivalent convex optimization problem. Then, we develop the optimal Qo E-driven power allocation scheme, which can maximize the effective capacity. The obtained simulation results verified our proposed power allocation scheme, showing that the effective capacity can be significantly increased compared with that of traditional Qo E guarantees based schemes.

关键词： wireless network effective capacity power allocation heterogeneous qualityof experience quality of service

Caching and D2D Assisted Wireless Emergency Communications Networks with Statistical QoS Provisioning

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Journal of Communications and Information Networks 2020年第3期5卷 282-293页

作者： jianyu wang Wenchi Cheng Hailin Zhang State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China

Along with natural disasters,the destruction of communication infrastructures leads to the congestion or failure of communication *** aerial vehicles(UAVs),which are with a high flexibility,can be employed as temporary base stations to establish emergency *** relieve the backhaul burden of UAVs,some imperative contents can be cached by terrestrial cache-enabled rescuers(CERs)and provide for victims with device-to-device(D2D)*** support the effectiveness and timeliness of emergency communication,the delay-bounded quality-of-service(QoS)requirement and network throughput are desired to be comprehensively considered,which imposes a new challenge for caching placement and CER *** this paper,we focus on joint caching placement and CER deployment to maximize the effective capacity subject to delay-bounded QoS *** overall non-convex problem is transformed into the caching placement and the CER deployment ***,we develop the QoS-aware caching placement scheme with fixed CER deployment density and obtain the QoS-aware CER deployment density with fixed caching *** on the block-coordinate descent method,we also propose the joint caching placement and CER deployment scheme,which can not only effectively enhance average effective capacity but also guarantee the delay-bounded QoS ***,numerical simulations are conducted to show the performances of the proposed schemes.

关键词： unmanned aerial vehicles(UAVs) device-todevice(D2D) emergency wireless networks quality-ofservice(QoS) caching placement effective capacity

An algorithm for solving new trust region subproblem with conic model

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Science China Mathematics 2008年第3期51卷 461-473页

作者： wang jianyu NI Qin Department of Mathematics Nanjing Xiaozhuang UniversityNanjing 211171China Department of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The new trust region subproblem with the conic model was proposed in 2005, and was divided into three different cases. The first two cases can be converted into a quadratic model or a convex problem with quadratic constraints, while the third one is a nonconvex problem. In this paper, first we analyze the nonconvex problem, and reduce it to two convex problems. Then we discuss some dual properties of these problems and give an algorithm for solving them. At last, we present an algorithm for solving the new trust region subproblem with the conic model and report some numerical examples to illustrate the efficiency of the algorithm.

关键词： conic model trust-region subproblem nonconvex problem dual method 49K10 90C30

Mensuration of microstructure multi-fractal spectra of calcined limestone particle surfaces

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Particuology 2010年第5期8卷 486-489页

作者： jianyu Shang Songling wang Chunbo wang Chunchang Song Department of Power Engineering North China Electric Power University Yonghua North Street Baoding 071002 Hebei China

The microstructure of the surface of a calcined limestone particle is multi-fractal. We develop an analytic method that surveys the boundary curve multi-fractal dimensions with SEM, gets a three-dimensional surface structure α α） curve via zero-sets, and finally calculates the multi-fractal spectrum values of the particle surface＇s microstructural topography. After analyzing two spectra from limestone particles calcined at 850℃ and 900℃, it was shown that the microstructural topographies of the surfaces of calcined limestone multi-particle system have some degree of self-similarity. This mensuration method is proposed to describe the multi-fractal characteristics of a micro-scale particle＇s surface topography.

关键词： LimestoneCalcined particleMicrostructure topographyMulti-fractalMeasureZero-sets

Non-line-of-sight reconstruction with signal–object collaborative regularization

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Light(Science & Applications) 2021年第10期10卷 1967-1986页

作者： Xintong Liu jianyu wang Zhupeng Li Zuoqiang Shi Xing Fu Lingyun Qiu Yau Mathematical Sciences Center Tsinghua University100084 BeijingChina State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua University100084 BeijingChina Key Laboratory of Photonic Control Technology(Tsinghua University) Ministry of Education100084 BeijingChina Department of Mathematical Sciences Tsinghua University100084 BeijingChina Yanqi Lake Beijing Institute of Mathematical Sciences and Applications 101408 BeijingChina

Non-line-of-sight imaging aims at recovering obscured objects from multiple scattered *** has recently received widespread attention due to its potential applications,such as autonomous driving,rescue operations,and remote ***,in cases with high measurement noise,obtaining high-quality reconstructions remains a challenging *** this work,we establish a unified regularization framework,which can be tailored for different scenarios,including indoor and outdoor scenes with substantial background noise under both confocal and non-confocal *** proposed regularization framework incorporates sparseness and non-local self-similarity of the hidden objects as well as the smoothness of the *** show that the estimated signals,albedo,and surface normal of the hidden objects can be reconstructed robustly even with high measurement noise under the proposed *** results on synthetic and experimental data show that our approach recovers the hidden objects faithfully and outperforms state-of-the-art reconstruction algorithms in terms of both quantitative criteria and visual quality.

关键词： regularization smoothness operations

Progress of Taiji-2 Project

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空间科学学报 2024年第4期44卷 674-676页

作者： LUO Ziren ZHANG Min wang jianyu WU Yueliang Taiji Laboratory for Gravitational Universe University of Chinese Academy of SciencesBeijing 100049 Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024 Institute of Mechanics Chinese Academy of SciencesBeijing 100190 International Center for Theoretical Physics Asia-Pacific University of Chinese Academy of SciencesBeijing 100190 Shanghai Institute of Technical Physics Chinese Academy of SciencesShanghai 200083

Taiji-2 project is the second step of Taiji program,which is to verify the required technology for Taiji-3 *** feasibility study of Taiji-2 is successfully finished,and some of the main progress is introduced here.

关键词： Gravitational wave Taiji program Taiji-2 project

From fluvial dynamics to eco-fluvial dynamics

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International Journal of Sediment Research 2019年第6期34卷 531-536页

作者： Guojian He Hongwei Fang jianyu wang Tao Zhang State Key Laboratory of Hydro-science and Engineering Department of Hydraulic EngineeringTsinghua University

Sediment plays a very important role in the functioning of river *** is the basic substance for the survival of benthic animals and aquatic *** the other hand,the growth of biofilms and biodisturbance of benthos affect the sediment transport *** the increasing attention to protect aquatic ecosystems,the importance of habitats has become increasingly *** need to study the interactions among sediment,flow,riverbed deformation,and aquatic ecosystems naturally leads to the proposed discipline of eco-fluvial *** this paper,the basic concept and main research content of eco-fluvial dynamics is introduced with the Yarlung Tsangpo River as the research *** case study is an example of an aquatic ecosystem in an ever-changing environment because of the effects of climate *** results of analysis of eco-fluvial dynamics will provide a scientific basis for decision support for the government.

关键词： Fluvial dynamics Eco-fluvial dynamics Water and sediment transport Aquatic ecosystems Interactive response

A modified universal pedestrian motion model: Revisiting pedestrian simulation with bottlenecks

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Building Simulation 2022年第4期15卷 631-644页

作者： jianyu wang Majid Sarvi Jian Ma Milad Haghani Abdullah Alhawsawi Juan Chen Peng Lin School of Transportation and Logistics Notional Engineering Laboratory of Integrated Transportation Big Data Application TechnologySouthwest Jiaotong UniversityChengdu 610031China Transport Engineering Group Melbourne School of Engineering&ITThe University of MelbourneVictoria 3070Australia Institute of Transport and Logistics Studies Business SchoolThe University of SydneyNSWAustralia Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 610031China

Pedestrian flow through narrow exits is one the most important features of crowd dynamics and *** is a particularly important aspect of pedestrian simulation models in that the accuracy is highly dependent on their ability to produce realistic exit flow *** firstly identified the four parameters that are most critical for physical interactions of the social force model and then calibrated them against two well-controlled pedestrian *** these calibrated parameters,we discussed the reasonable settings of sensitive parameters for different levels of pedestrian ***,we revisited the basic questions about the effect of the exit location,the bottleneck length,and the effect of obstacles on pedestrian *** simulation results indicated that:(1)The effect of the exit location on the pedestrian egress efficiency is uncertain,and the evacuation efficiency is also related to the exit width and the level of urgency.(2)The"pass-way"after the exit also named as the bottleneck length has a negative impact on the evacuation performance only in the scenarios that the bottleneck length is not more than 2.0 *** the bottleneck length exceeds 2.0 meters,pedestrian outflow efficiency reaches an asymptotic.(3)Setting an obstacle near an exit is not leading to a longer pedestrian evacuation time,instead,it is effectively improving pedestrian evacuation.

关键词： bottleneck pedestrian crowd simulation exit location bottleneck length obstacles location