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A DQN-Based Cache Strategy for Mobile Edge Networks

Computers, Materials & Continua 2022年第5期71卷 3277-3291页

作者： Siyuan Sun Junhua Zhou Jiuxing Wen Yifei Wei Xiaojun Wang School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing100876China State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System EngineeringBeijing100854China Ningbo Sunny Intelligent Technology Co. LTDYuyao315400China Dublin City University Dublin 9Ireland

The emerging mobile edge networks with content caching capability allows end users to receive information from adjacent edge servers directly instead of a centralized data warehouse,thus the network transmission delay and system throughput can be improved *** the duplicate content transmissions between edge network and remote cloud can be reduced,the appropriate caching strategy can also improve the system energy efficiency of mobile edge networks to a great *** paper focuses on how to improve the network energy efficiency and proposes an intelligent caching strategy according to the cached content distribution model for mobile edge networks based on promising deep reinforcement learning *** deep neural network(DNN)and Q-learning algorithm are combined to design a deep reinforcement learning framework named as the deep-Q neural network(DQN),in which the DNN is adopted to represent the approximation of action-state value function in the Q-learning *** parameters iteration strategies in the proposed DQN algorithm were improved through stochastic gradient descent method,so the DQN algorithm could converge to the optimal solution quickly,and the network performance of the content caching policy can be *** simulation results show that the proposed intelligent DQN-based content cache strategy with enough training steps could improve the energy efficiency of the mobile edge networks significantly.

关键词： Mobile edge network edge caching energy efficiency

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MTL-JER: Meta-Transfer Learning for Low-Resource Joint Entity and Relation Extraction 3

MTL-JER: Meta-Transfer Learning for Low-Resource Joint Entit...

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3rd International Conference on Neural Networks, Information and Communication engineering, NNICE 2023

作者： Peng, Da Pei, Zhongmin Mo, Delin Space Engineering University Science and Technology on Complex Electronic System Simulation Laboratory Beijing China Institute of War Studies Academy of Military Sciences

ISBN: (纸本)9798350335972

Joint entity and relation extraction has achieved impressive advances in NLP, such as document understanding and knowledge graph construction. The typical methods for entity and relation extraction typically break down the joint task into several smaller components or stages for ease of implementation, but this leads to a loss of the interconnected knowledge in the triple. Hence, we propose to model the triple in one module jointly. Furthermore, the labeling of a joint entity and relation extraction tasks is costly and domain-specific;therefore, it is important to improve its performance on low-resource data and domain adaption. To address this issue, we suggest using two sources that are rich in information, namely pre-trained models on large data and multi-domain text corpora. Pretraining allows us to provide the model with the fundamental ability to perform joint entity and relationship extraction. Second, through meta-learning on multi-domain text, we can improve the model's generalization capabilities, enabling it to perform well even with limited data. We present MTL-JER, a Meta-Transfer Learning method for Joint Entity and Relation Extraction in low-resource settings in this paper. Using exhaustive experiments on five datasets, we prove that our model obtains optimal results. © 2023 IEEE.

关键词： Extraction

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key technologies of GNSS/INS/VO deep integration for UGV navigation in urban canyon 11

Key technologies of GNSS/INS/VO deep integration for UGV nav...

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2017 11th Asian Control Conference, ASCC 2017

作者： Meiling, Wang Yafeng, Li Guoqiang, Feng Yi, Yang Tong, Liu Xiao, Xuan School of Automation State Key Laboratory of Complex System Intelligent Control and Decision Beijing Institute of Technology Beijing100081 China

ISBN: (纸本)9781509015733

As a new emerging integrated navigation technology, the GNSS/INS/VO deep integration system can fully leverage the synergistic and complementary characteristics of the three involved subsystems to achieve cost reduction while improving navigation accuracy, availability, and robustness, by mutual aiding between subsystems. In this paper, firstly, based on a brief review of the technical background and research status of the GNSS/INS/VO deep integration technology, the processing flows of this deep integration mode in both signal and information domains are analyzed, and its performance advantages are summarized. Then, the top-level technology roadmap of the GNSS/INS/VO deep integration for UGV navigation in the urban canyon is presented, and several key technical issues from scheme demonstration to engineering implementation are explored. At last, the short and medium term development prospects of the GNSS/INS/VO deep integration are envisaged. The proposed research ideas and system design concept for GNSS/INS/VO deep integration could be used as a reference for relevant technicians in navigation field. © 2017 IEEE.

关键词： Navigation

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YOLO-based multi-class target detection for SAR images 7

YOLO-based multi-class target detection for SAR images

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7th IEEE Information Technology and Mechatronics engineering Conference, ITOEC 2023

作者： Qiu, Linlin Zhu, Weigang Li, Yonggang Qiu, Lei Ma, Fanyin Space Engineering University Graduate School Beijing China Key Laboratory of Complex Electronic System Simulation China Space Engineering University Department of Electronics and Optical Engineering Beijing China

ISBN: (纸本)9798350334197

The current SAR image target detection mainly focuses on single category target detection problem in single task scenario, and no research has been conducted on multi-category target detection in different scenarios. YOLO is widely used in target detection tasks because of its speed and accuracy. In this paper, the YOLOv3, YOLOv5 and YOLOv8 algorithms, which have better detection performance and are more widely used, are used to perform target detection on the SAR image multi-category target detection dataset MSAR-1.0, and the detection results are analyzed from both the SAR image multi-category target detection dataset and the YOLO algorithm. © 2023 IEEE.

关键词： Synthetic aperture radar

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A parallel based real-time electromagnetic transient simulator for IPS

A parallel based real-time electromagnetic transient simulat...

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Electric Ship Technologies Symposium

作者： Gong, Yuan Chen, Laijun Chen, Ying Xu, Yin State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781424492725

IPS has many special characteristics, such as using multi-phase, multi-frequency and hybrid AC/DC devices. As a result, existing electromagnetic transient simulators developed for power systems on land do not apply to IPS. This paper aims to build up a parallel based real-time electromagnetic transient simulator for IPS. A fast multi-switching process method for parallel electromagnetic transient simulations is coined to handle the tremendous switch events in IPS. To solve the difficulties brought by multi-phase machines in IPS, a multilevel hybrid parallel algorithm is forged through the combination of component level and network level parallelization. Based on the key techniques mentioned above, a parallel simulator is built up. Through sufficient testing to typical examples of IPS, the accuracy and high-efficiency of the simulator are proved. © 2011 IEEE.

关键词： Simulators

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A Dual-Motor Joint Model for Humanoid Robots

A Dual-Motor Joint Model for Humanoid Robots

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第25届中国控制与决策会议

作者： Jingtao Xue Xiaopeng Chen Ye Tian Zhangguo Yu Fei Meng Qiang Huang IRI School of Mechatronic Engineering Beijing Institute of Technology Key Laboratory of Biomimetic Robots and Systems Ministry of Education Key Laboratory of Intelligent Control and Decision of Complex System

ISBN: (纸本)9781467355339

To make humanoid robots walking fast, it's important to improve driving force of their leg joints. Usually, each joint of humanoid robots is driven by a single motor. Dual-motor joint, on the other hand, is one of the candidate solutions to meet the power requirement needed for fast walking. This paper proposed a new dual-motor control model. In the model, two motors are treated as a single control plant instead of two parallel control plants. With the usage of current distributor, the control model can pump different current to each motor freely so as to eliminate the unbalance of the load imposed on each motor. simulation and experiment show that the proposed model works well under high joint load and it can be used on a fast walking humanoid robot.

关键词： Humanoid robot, dual motor, control model

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A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO_4-H_2O and NaF-H_2O binary solutions and NaClO_4-NaF-H_2O ternary solution

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 546-557页

作者： Xue-min Yang Wei-jie Zhao Han-jie Guo Qiang Zhang Jian Zhang State Key Lab of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Metallurgical Equipment Research ＆ Design Corporation Ltd. China Metallurgical Group Corporation Beijing 100029 China

A thermodynamic model of calculating mass action concentrations for structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions and NaClO4-NaF-H2O ternary strong electrolyte aqueous solutions was developed based on the ion and molecule coexistence theory （IMCT）. A transformation coefficient was needed to compare the calculated mass action concentration and the reported activity, because they were usually obtained at different standard states and concentration units. The results show that transformation coefficients between the calculated mass action concentrations and the reported activities of the same components change in a very narrow range. The transformed mass action concentrations of structural units or ion couples in NaClO4-H2O and NaF-H2O binary solutions agree well with the reported activities. The transformed mass action concentrations of structural units or ion couples in NaClO4-NaF-H2O ternary solution are also in good agreement with the reported activities in a total ionic strength range from 0.1 to 0.9 mol/kg H2O by the 0.1 mol/kg step with different ionic strength fractions of 0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1, respectively. The results indicate that the developed thermodynamic model can reveal the structural characteristics of binary and ternary strong electrolyte aqueous solutions, and the calculated mass action concentrations of structural units or ion couples also strictly follow the mass action law.

关键词： binary systems ternary systems thermodynamic model activity coefficient structural unit

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NUMERICAL simulation OF SURFACE DISCHARGE IN OIL PAPER INSULATION BASED ON FINITE ELEMENT METHOD AND CELLULAR AUTOMATA 22

NUMERICAL SIMULATION OF SURFACE DISCHARGE IN OIL PAPER INSUL...

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22nd International Symposium on High Voltage engineering, ISH 2021

作者： Chen, Jianning Zhou, Yuanxiang Zhang, Yunxiao Huang, Xin Zhang, Ling State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781839536052

Surface discharge of oil paper insulation is one of the insulation defects in converter transformers. However, the mechanism of surface discharge in oil paper insulation remains unclear. A novel method of surface discharge in oil paper insulation based on finite element method (FEM) and cellular automata (CA) was proposed to study the mechanism and fractal characteristics. Firstly, the needle-plate electrode without normal component of electric field density was adopted as the geometric model, on which the unstructured triangular mesh generation was performed. Then, the FEM is applied to compute the distribution of potential, electric field and charge in the simulated field, which performed better than finite difference method (FDM) in accuracy and complexity of computation. Finally, the CA model was adopted to simulate the development of surface discharge with the electric field threshold. The results indicated that the numerical simulation model based on FEM-CA can simulate the dynamic process and fractal characteristics of surface discharge in oil paper insulation. According to the fractal dimension curve, the surface discharge can be obviously divided into three stages: inception, propagation and flashover. With the increase of applied voltage, the fractal dimension of surface discharge increases in inception stage, then decreases in propagation stage, and finally increases in flashover stage. © 2021 The Institution of engineering and Technology.

关键词： Cellular automata

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IGBT modeling for analysis of complicated multi-IGBT circuits

IGBT modeling for analysis of complicated multi-IGBT circuit...

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2009 2nd Conference on Power Electronics and Intelligent Transportation system, PEITS 2009

作者： Deng, Yi Zhao, Zhengming Yuan, Liqiang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781424442461

A new IGBT (Insulated Gate Bipolar Transistor) model for simulation of eomplicated multi-IGBT cireuits is presented. Based on the gate chargc and discharge behaviors of IGBT, it piecewise models the turn-on and -off transient oflGBT, and simulates the static characteristics with curve fitting method . With the kcy features of high simulation spccd, easy parameters extraction and clear physical meaning, the model is available for various IGBTs and system level circuits. This paper describes the structure and equivalent circuit of the model in detail, implements it with the simulation tool of PSIM package, and determines the parameters of the model for an IGBT of FF300R12ME3 as an example. The accuracy of the model is verified by the comparison between the simulated and experimental results. ©2009 IEEE.

关键词： Equivalent circuits

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Nonlinear dynamic characteristic analysis of a vertical mass unbalanced rotor

Nonlinear dynamic characteristic analysis of a vertical mass...

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23rd International Congress on Condition Monitoring and Diagnostic engineering Management, COMADEM 2010

作者： An, Xueli Jiang, Dongxiang Liu, Chao Zhao, Minghao State Key Laboratory of Control and Simulation of Power System Generation Equipment Department of Thermal Engineering Tsinghua University Beijing China

ISBN: (纸本)9784883254194

The dynamic properties between torsional and bending vibrations of a vertical mass unbalanced rotor are described. The equation of rotor system motion is obtained by Lagrangian dynamics without considering the external actuating forces and torque, shows coupling effect and nonlinear interaction between the rotor system bending and torsional vibrations. An attempt of theoretical analysis and numerical simulation is made to reveal dynamic characteristics of a rotor system. Theoretical analysis of the rotor dynamic equations based on perturbation theory indicates that at stable state of vibration the coupled effect on the rotor system is nonexistent and the bending vibration becomes equal amplitude with shafting speed at stable vibration state. While the torsional vibration keeps on attenuating until it stops. In addition, the numerical simulation results to the dynamic equations, show that coupled torsional and bending vibrations are induced by mass eccentricity, and coupled effect can only be found in vibration initial state of the rotor system. Other numerical simulation results are consistent with the theoretical analysis.

关键词： Perturbation techniques

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