检索结果-南通市图书馆

Reinforcement Learning Based Data Fusion Method for Multi-Sensors

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2020年第6期7卷 1489-1497页

作者： Tongle zhou Mou Chen Jie Zou College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China IEEE Science and Technology on Electron-Optic Control Laboratory Luoyang Institute of Electro-Optical Equipment of AvicLuoyang 471023China

In order to improve detection system robustness and reliability, multi-sensors fusion is used in modern air combat. In this paper, a data fusion method based on reinforcement learning is developed for multi-sensors. Initially, the cubic B-spline interpolation is used to solve time alignment problems of multisource data. Then, the reinforcement learning based data fusion(RLBDF) method is proposed to obtain the fusion results. With the case that the priori knowledge of target is obtained, the fusion accuracy reinforcement is realized by the error between fused value and actual value. Furthermore, the Fisher information is instead used as the reward if the priori knowledge is unable to be obtained. Simulations results verify that the developed method is feasible and effective for the multi-sensors data fusion in air combat.

关键词： Air combat cubic B-spline interpolation data fusion reinforcement learning

DQNN: Pore-scale variables-based digital permeability assessment of carbonates using quantum mechanism-based machine-learning

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2022年第2期65卷 458-469页

作者： ZHAO Zhi zhou XiaoPing QIAN QiHu School of Civil Engineering Wuhan UniversityWuhan 430072China School of Civil Engineering Chongqing UniversityChongqing 400045China State Key Laboratory of Disaster Prevention and Mitigation of Explosion and Impact PLA University of Science and TechnologyNanjing 210014China

Permeability is a key parameter of rock reservoirs, suggesting the flow characteristics of rock reservoirs. Permeability prediction of carbonate reservoirs is still a great challenge due to its complex pore network and wide range permeability. This work is to establish a digital quantum mechanism-based neural network(DQNN) to study the permeability using the digital porosity,coordination number and pore network size. Experiments and artificial neural network methods(ANN) are applied to validate the accuracy of the proposed DQNN method. In these methods, the pore-scale variables extracted from the micro-CT images of200 carbonate samples are applied. Results show that the permeabilities obtained from experimental, artificial neural network and DQNN methods agree well with each other. Digital pore size, pore throat size and length are better parameters, while coordination number and porosity are relatively secondary parameters for permeability descriptions of carbonate *** with the ANN method, the proposed DQNN method is superior in low computation time and high ability for complicated problems.

关键词： permeability estimation quantum mechanism machine-learning model micro-pore network carbonates

State estimation in range coordinate using range-only measurements

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2022年第3期33卷 497-510页

作者： LI Keyi GUO Zhengkun zhou Gongjian School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China

In some tracking applications,due to the sensor characteristic,only range measurements are *** this is the case,due to the lack of full position measurements,the observability of Cartesian states(e.g.,position and velocity)are limited to particular *** general cases,the range measurements can be utilized by developing a state estimation algorithm in range-Doppler(R-D)plane to obtain accurate range and Doppler *** this paper,a state estimation method based on the proper dynamic model in the R-D plane is *** unscented Kalman filter is employed to handle the strong nonlinearity in the dynamic *** filtering initialization methods are derived to extract the initial state estimate and the initial covariance in the R-D plane from the first several range *** is derived based on the well-known two-point differencing *** other incorporates the correct dynamic model information and uses the unscented transformation method to obtain the initial state estimates and covariance,resulting in a model-based method,which capitalizes the model information to yield better *** Carlo simulation results are provided to illustrate the effectiveness and superior performance of the proposed state estimation and filter initialization methods.

关键词： range-only measurement state estimation filter initialization target tracking unscented Kalman filter(UKF)

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2020年第1期14卷 191-207页

作者： Huiping LIU Cheqing JIN Aoying zhou School of Data Science and Engineering School of Computer Science and Software EngineeringEast China Normal UniversityShanghai 200062China

With the increasing number of GPS-equipped vehicles,more and more trajectories are generated continuously,based on which some urban applications become feasible,such as route *** general,popular route that has been travelled frequently is a good choice,especially for people who are not familiar with the road ***,accurate estimation of the travel cost(such as travel time,travel fee and fuel consumption)will benefit a wellscheduled trip *** this paper,we address this issue by finding the popular route with travel cost *** this end,we design a system consists of three main ***,we propose a novel structure,called popular traverse graph where each node is a popular location and each edge is a popular route between locations,to summarize historical trajectories without road network ***,we propose a self-adaptive method to model the travel cost on each popular route at different time interval,so that each time interval has a stable travel ***,based on the graph,given a query consists of source,destination and leaving time,we devise an efficient route planning algorithmwhich considers optimal route concatenation to search the popular route from source to destination at the leaving time with accurate travel cost ***,we conduct comprehensive experiments and implement our system by a mobile App,the results show that our method is both effective and efficient.

关键词： location-based services route planning travel cost estimation minimum description length optimal road concatenation

Natural Feature-based Visual Servoing for Grasping Target with an Aerial Manipulator

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2020年第2期17卷 215-228页

作者： bin Luo Haoyao Chen Fengyu Quan Shiwu Zhang Yunhui Liu School of Mechanical Engineering and Automation Harbin Institute of Technology ShenzhenShenzhen 518055China Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China Department of Mechanical and Automation Engineering Chinese University of Hong KongHong Kong 999077China

Aerial transportation and manipulation have attracted increasing attention in the unmanned aerial vehicle field,and visual servoing methodology is widely used to achieve the autonomous aerial grasping of a target ***,the existing marker-based solutions pose a challenge to the practical application of target grasping owing to the difficulty in attaching markers on *** address this problem,this study proposes a novel image-based visual servoing controller based on natural features instead of artificial *** natural features are extracted from the target images and further processed to provide servoing feature points.A six degree-of-freedom(6-DoF)aerial manipulator system is proposed with differential kinematics deduced to achieve aerial ***,a controller is designed when the target object is outside a manipulator's workspace by utilizing both the degrees-of-freedom of nnmanned aerial vehicle and manipulator ***,a weight matrix is used as basis to develop a multi-tasking visual servoing framework to integrate the controllers inside and outside the manipulator's ***,experimental results are provided to verify the effectiveness of the proposed approach.

关键词： unmanned aerial manipulator visual servoing aerial grasping multi-tasking strategy

Service Migration Algorithm Based on Markov Decision Process with Multiple Service Types and Multiple System Factors

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第6期33卷 1515-1525页

作者： Anhua MA Su PAN Weiwei zhou Broadband Wireless Communication College Nanjing University of Posts and Telecommunications School of Computer Science and Technology Nanjing Tech University

This paper proposes a Markov decision process based service migration algorithm to satisfy quality of service(QoS) requirements when the terminals leave the original server. Services were divided into real-time services and non-real-time services, each type of them has different requirements on transmission bandwidth and latency,which were considered in the revenue function. Different values were assigned to the weight coefficients of QoS parameters for different service types in the revenue and cost functions so as to distinguish the differences between the two service types. The overall revenue was used for migration decisions, rather than fixed threshold or instant *** Markov decision process was used to maximize the overall revenue of the system. Simulation results show that the proposed algorithm obtained more revenue compared with the existing works.

关键词： Energy consumption Costs Markov decision processes Simulation Quality of service Market research Cost function Real-time systems Energy efficiency Servers

Effect of anionic group[SiO_(4)]^(4-)/[PO_(4)]^(3-) on the luminescence properties of Dy^(3+)-doped tungstate structural compounds

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2021年第4期10卷 843-851页

作者： Ning LIU Lefu MEI Jianxiong bin Ze ZHANG Zhijian PENG School of Science China University of Geosciences(Beijing)Beijing 100083China Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral MaterialsSchool of Materials Sciences and TechnologyChina University of Geosciences(Beijing)Beijing 100083China

Novel scheelite structures of Li_(2)Ca(WO_(4))_(2),Li_(2)Ca_(2)(WO_(4))(SiO_(4)),and LiCa_(2)(WO_(4))(PO_(4))fluorescent materials were successfully prepared using a high-temperature solid-phase *** compounds were characterized by X-ray diffraction and energy dispersive *** tests revealed that the substitution of[WO_(4)]^(2-)by[SiO_(4)]^(4-) or [PO_(4)]^(3-) tetrahedron in tungstate had no significant influence on the crystal structure of the Li_(2)Ca(WO_(4))_(2).When Dy^(3+) ions were introduced as an activator at an optimum doping concentration of 0.08 mol%,all of the as-prepared phosphors generated yellow light emissions,and the emission peak was located close to 576 ***[WO_(4)]^(2-) with [SiO_(4)]^(4-) or [PO_(4)]^(3-) tetrahedron significantly increased the luminescence of the Li_(2)Ca(WO_(4))_(2) *** them,the LiCa_(2)(WO_(4))(PO_(4)):0.08Dy^(3+) phosphor had the best luminescence properties,decay life(r=0.049 ms),and thermal stability(87.8%).In addition,the as-prepared yellow Li_(2)Ca(WO_(4))_(2):0.08Dy^(3+),Li_(2)Ca_(2)(WO_(4))(SiO_(4)):0.08Dy^(3+),and LiCa_(2)(WO_(4))(PO_(4)):0.08Dy^(3+) phosphor can be used to fabricate white light emitting diode(LED)devices.

关键词： phosphors scheelite structure luminescence property anion substitution

Fault Detection Method for Permanent Magnet Synchronous Generator Wind Energy Converters Using Correlation Features Among Three-phase Currents

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2020年第1期8卷 168-178页

作者： Yanghong Tan Haixia Zhang Ye zhou College of Electrical and Information Engineering Hunan UniversityChangshaChina NARI Group Corporation(State Grid Electric Power Research Institute) NanjingChina

In a permanent magnet synchronous generator(PMSG)system,conversion systems are major points of failure that create expensive and time-consuming *** detection is usually used to achieve a steady *** paper presents a full analysis of a PMSG system for wind turbines(WT)and proposes a fault detection method using correlation *** proposed method is motivated by the balance among the three-phase currents both before and after an opencircuit fault occurs in a converter of the PMSG *** is unnecessary to analyze the output waveforms of a converter during fault *** this study,two correlation features of stator currents,the mean and covariation,are extracted to train an artificial neural network(ANN),thereby enhancing the performance of the proposed method under different wind speed ***,additional sensors and the collection of a massive amount of data are not *** simulations of an ideal inverter and a PMSG system are conducted using PSCAD *** simulation results show that the proposed method can detect the locations of faulty switches with a diagnostic rate greater than 99.4%for the ideal inverter,and the PMSG drives settings at different wind speeds.

关键词： Permanent magnet synchronous generator(PMSG) artificial neural network(ANN) mixed logical dynamical(MLD)theory conversion system

Low-temperature processing of LiZn-based ferrite ceramics by co-doping of V_(2)O_(5)and Sb_(2)O_(3):Composition,microstructure and magnetic properties

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第4期99卷 1-8页

作者： Renquan Wang Tingchuan zhou Zhiyong Zhong College of Materials Science and Engineering Sichuan UniversityChengdu 610065China Key Laboratory of Advanced Special Materials&Technology Ministry of EducationChengdu 610065China State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China

Low-temperature fired ferrites or ceramics are usually processed by using low-melting materials(e.g.,glasses,oxides,and eutectics)as sintering aids to obtain compact and uniform ***,a dual-strategy of co-doping with V_(2)O_(5)and Sb_(2)O_(3)oxides and forming a eutectic liquid phase has been employed to reduce the melting point of LiZn ferrite ceramics in an effective *** results indicate that miniscule amounts of V_(2)O_(5)and Sb_(2)O_(3)co-doping contribute in producing dense and uniform microstructures with enhanced magnetic performance by low-temperature *** phase structural and microstructural evolutions have been studied in *** their correlations with magnetic properties have been *** magnetic performance(B_(s)=475.4 mT,M_(s)=82.51 emu/g,B_(r)/B_(s)=0.85,H_(c)=2.2 Oe,ΔH=153.8 Oe)of the LiZn-based ferrite ceramics is achieved by optimized composition and microstructure,which shows great potential for microwave applications including phase shifters and *** importantly,such a co-doping strategy can be also extended to other material systems,like dielectric ceramics,hexagonal ferrites or piezoelectric ceramics.

关键词： Low-temperature firing Eutectic liquid phase Magnetic properties Uniform microstructure FMR line width