检索结果-内蒙古大学图书馆

International Conference on Wavelet Active Media technology and Information Processing (ICWAMTIP)

作者： Xiang Tao Liu Jie Qiao Wenshen Xiao Siying Ye Mao National Key Laboratory of Complex Aviation System Simulation Southwest China Institute of Electronic Technology Chengdu China University of Electronic Science and Technology of China Chengdu China

ISBN: (数字)9798331519254

ISBN: (纸本)9798331519261

At present, most of the existing methods combine the data from different views mechanically to obtain the latent subspace with complementary information, which not only fails to make full use of the data information from specific perspectives but also brings redundancy. Therefore, we propose a novel multi-view subspace clustering method. It utilizes cycle projection to obtain a subspace construction model. At the same time, by learning the global structure and local manifold structure of this subspace while assigning learnable weights to different views, the consensus information among views and specific information from different views are captured according to the importance of different views. In this way, our method effectively reduces the original noise and redundancy, and further carries out the improvement of complementarity and consistency among views. The proposed method is optimized by using the Augmented Lagrangian Multiplier with Alternating Direction Minimization (ALM- ADM) algorithm. Experiment results on benchmark datasets confirm the effectiveness of our method.

关键词： Manifolds Technological innovation Clustering methods Redundancy Noise Clustering algorithms Information processing Media Minimization Similarity learning

来源：评论

学校读者我要写书评

暂无评论

Machine Learning-Based Channel Power Analysis inside Aircraft Cabin

Machine Learning-Based Channel Power Analysis inside Aircraf...

引用

2023 International Conference on Intelligent Computing and Control, IC and C 2023

作者： Ye, Xijuan Mao, Kai Ma, Jian Song, Lixin Liu, Yuxin Zhu, Qiuming Ministry of Industry and Information Technology Nanjing University of Aeronautics and Astronautics Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space Nanjing China Aeronautical Key Laboratory of Aeronautical Science and Technology Nanjing Mechanical and Electrical Hydraulic Engineering Research Center of Aviation Industry Nanjing China

ISBN: (纸本)9781665457095

Communication inside aircraft cabin has gained more and more attentions to provide in-flight connectivity for high-quality user experience and enable the wireless communication of electromechanical equipment. In this paper, a power prediction method considering the coordinates of transceiver, propagation distance and carrier frequency based on the parameterized channel model and machine learning (ML) framework is proposed for wireless communication inside the aircraft cabin. In the proposed channel model, a random forest (RF) network is trained for channel characteristics based on ray tracing (RT) simulation data and applied to estimate the power parameters. The proposed method is verified inside a typical aircraft cabin at 1GHz and compared with traditional model and background propagation neural network (BPNN). The simulation results show that RF can accurately predict the power parameter and reproduce the channel environment. The prediction results of power distribution can provide valuable reference for the layout and optimization of communication nodes inside the aircraft cabin. © 2023 IEEE.

关键词： Forecasting

来源：评论

学校读者我要写书评

暂无评论

Ascent Trajectory Planning for Combined-Power Reusable Launch Vehicles Based on the DDPG Algorithm

Ascent Trajectory Planning for Combined-Power Reusable Launc...

引用

Chinese Automation Congress (CAC)

作者： Xinhua Zhao Kelong Han Meng Wang Jintao Li Fei Zong Harbin Engineering University College of Intelligent System Science and Engineering Harbin China China Academy of Space Technology Qian Xuesen Laboratory of Space Technology Beijing China

ISBN: (数字)9798350368604

ISBN: (纸本)9798350368611

This paper proposes an ascent phase trajectory planning method for combined-cycle reusable launch vehicles (CRLV) based on the DDPG algorithm. First, the motion model and flight constraint model for the vehicle's ascent phase were established. Based on these constraints and flight characteristics, a Markov Decision Process (MDP) was designed using the DDPG algorithm to meet flight requirements, addressing the online trajectory planning problem for the CRLV. The vehicle can calculate the optimal control values in real time based on its current motion state. Finally, by comparing the optimization results of the DDPG algorithm and the Particle Swarm Optimization (PSO) algorithm, the superiority and effectiveness of the proposed method were fully demonstrated.

关键词： Training Uncertainty Trajectory planning Heuristic algorithms Markov decision processes Optimal control Real-time systems Vehicle dynamics Particle swarm optimization Optimization

来源：评论

学校读者我要写书评

暂无评论

Recent Advances in space-Deployable Structures in China

引用

Engineering 2022年第10期17卷 207-219页

作者： Xiaofei Ma Tuanjie Li Jingya Ma Zhiyi Wang Chuang Shi Shikun Zheng Qifeng Cui Xiao Li Fan Liu Hongwei Guo Liwu Liu Zuowei Wang Yang Li Xi’an Institute of Space Radio Technology Xi’an 710100China School of Electromechanical Engineering Xidian UniversityXi’an 710071China Beijing Institute of Spacecraft System Engineering Beijing 100094China Aerospace System Engineering Shanghai Shanghai 201109China State Key Laboratory of Robotics Harbin Institute of TechnologyHarbin 150001China Department of Astronautical Science and Mechanics Harbin Institute of TechnologyHarbin 150001China

Deployable space structure technology is an approach used in building spacecraft,especially when realizing deployment and folding *** in orbit,the structures are released from the fairing,deployed,and *** the development of communication,remote-sensing,and navigation satellites,space-deployable structures have become cutting-edge research topics in space science and *** paper summarizes the current research status and development trend of spacedeployable structures in China,including large space mesh antennas,space solar arrays,and deployable structures and mechanisms for deep-space *** technologies of space-deployable structures are addressed from the perspectives of deployable mechanisms,cable-membrane form-finding,dynamic analysis,reliable environmental adaptability analysis,and ***,future technology developments and trends are elucidated in the fields of mesh antennas,solar arrays,deployable mechanisms,and on-orbit adjustment,assembly,and construction.

关键词： Deployable space structures Mesh antennas Solar arrays Deep-space exploration

来源：评论

学校读者我要写书评

暂无评论

Health benefits from the rapid reduction in ambient exposure to air pollutants after China's clean air actions:progress in efficacy and geographic equality

引用

National science Review 2024年第2期11卷 103-113页

作者： Tao Xue Ruohan Wang Meng Wang Yanying Wang Dan Tong Xia Meng Conghong Huang Siqi Ai Fangzhou Li Jingyuan Cao Mingkun Tong Xueqiu Ni Hengyi Liu Jianyu Deng Hong Lu Wei Wan Jicheng Gong Shiqiu Zhang Tong Zhu Institute of Reproductive and Child Health National Health Commission Key Laboratory of Reproductive Health/Department of Epidemiology and Biostatistics Ministry of Education Key Laboratory of Epidemiology of Major Diseases(PKU) School of Public Health Peking University Health Science Centre State Environmental Protection Key Laboratory of Atmospheric Exposure and Health Risk Management and Center for Environment and Health Peking University Advanced Institute of Information Technology Peking University Department of Epidemiology and Environmental Health School of Public Health and Health ProfessionsUniversity at Buffalo State Key Joint Laboratory of Environment Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University Department of Earth System Science Tsinghua University School of Public Health Key Laboratory of Public Health Safety of the Ministry of Education and Key Laboratory of Health Technology Assessment of the Ministry of HealthFudan University College of Land Management Nanjing Agricultural University National&Local Joint Engineering Research Center for Rural Land Resources Use and Consolidation Clean Air Asia

Clean air actions （CAAs） in China have been linked to considerable benefits in public ***,whether the beneficial effects of CAAs are equally distributed geographically is *** high-resolution maps of the distributions of major air pollutants (fine particulate matter[PM2.5]and ozone[O3]) and population,we aimed to track spatiotemporal changes in health impacts from,and geographic inequality embedded in,the reduced exposures to PM2.5and O3from 2013 to *** used a method established by the Global Burden of Diseases *** analyzing the changes in loss of life expectancy（LLE） attributable to PM2.5and O3,we calculated the gain of life expectancy （GLE） to quantify the health benefits of the air-quality ***,we assessed the geographic inequality embedded in the GLE using the Gini index （GI）.Based on risk assessments of PM2.5and O3,during the first stage of CAAs（2013 to 2017）,the mean GLE was 1.87 *** of the sum of the GLE was disproportionally distributed in about one quarter of the population exposed （GI 0.44）.During the second stage of CAAs（2017 to 2020）,the mean GLE increased to 3.94 months and geographic inequality decreased （GI 0.18）.According to our assessments,CAAs were enhanced,from the first to second stages,in terms of not only preventing premature mortality but also ameliorating health *** enhancements were related to increased sensitivity to the health effects of air pollution and synergic control of PM2.5and *** findings will contribute to optimizing future CAAs.

关键词： clean air action public health inequality fine particulate matter ozone

来源：评论

学校读者我要写书评

暂无评论

Heuristic Task Allocation Method for Heterogeneous Lunar Robots under Dynamic Resource Cost

Heuristic Task Allocation Method for Heterogeneous Lunar Rob...

引用

2024 IAF space Operations Symposium at the 75th International Astronautical Congress, IAC 2024

作者： Xu, Rui Zhou, Junhui Li, Zhaoyu Zhu, Shengying Pan, Bo Zhao, Zhijun Yu, Dengyun School of Aerospace Engineering Beijing Institute of Technology Beijing100081 China Key Laboratory of Autonomous Navigation and Control for Deep Space Exploration Ministry of Industry and Information Technology Beijing100081 China Beijing Institute of Spacecraft System Engineering Beijing100094 China China Aerospace Science and Technology Corporation Beijing100048 China

ISBN: (纸本)9798331312183

China, in collaboration with multiple countries, is preparing to construct a long-term, independently operated international lunar research station on the surface of the moon in the coming years. The construction of an unmanned lunar research station requires the collaboration of diverse and heterogeneous lunar robots to successfully carry out missions. Task allocation for heterogeneous lunar robots is a crucial technical requirement, focusing on constructing evaluation matrix, designing optimization objective functions, and developing algorithms for optimization matching. The state changes during the execution of tasks by robots result in different resource costs for completing other task goals compared to the initial resource costs. Therefore, one of the major challenges in task allocation for multi-robot systems is effectively managing dynamic resource costs during the construction of evaluation matrix (and subsequent optimization based on the matrix). However, the current approach tends to calculate static cost without considering cost changes during task execution, which deviates from standard engineering practices. Instead, the primary contribution of this paper lies in designing a heuristic algorithm capable of optimizing task allocation outcomes while accounting for the dynamic changes in resource costs incurred during goal achievement. In this paper, we propose a heuristic task allocation method for heterogeneous lunar robots under dynamic resource cost. Given a multi-robot cooperative task, our method firstly constructs a task allocation model based on robotic capability and task resource consumption. Next, based on relaxation planning graph, the resource cost for each lunar rover to complete all task goals is calculated, and the cost of transitioning between different goal states is estimated (to efficiently update the resource cost of completing each goal as the lunar rover's state changes). Subsequently, the evaluation matrix is constructed. Then, a heu

关键词： Multipurpose robots

来源：评论

学校读者我要写书评

暂无评论

A Programming Language Learning Service by Linking Stack Overflow with Textbooks

A Programming Language Learning Service by Linking Stack Ove...

引用

2023 IEEE International Conference on Web Services, ICWS 2023

作者： Wu, Jiawei Sun, Yanchun Zhang, Jiaqi Zhou, Yuqi Huang, Gang Ministry of Education Key Laboratory of High Confidence Software Technologies China Peking University School of Computer Science Beijing China Peking University School of Software and Microelectronics Beijing China National Key Laboratory of Data Space Technology and System China

ISBN: (纸本)9798350304855

Before software developers actually start coding, an essential requirement is to be proficient in a programming language. However, as an important learning resource, programming language textbooks usually contain much about syntax and semantics of a programming language, but little about pragmatics, which is highly relevant with practical skills in solving real-world problems using programming languages. This makes it difficult for learners to transfer knowledge from textbooks to *** solve this problem, this paper proposes a programming language learning service, utilizing abundant development knowledge in Stack Overflow (SO) Q&A posts as the pragmatics knowledge of programming languages to make up for the shortage of pragmatics knowledge in textbooks. To link SO Q&A posts with textbooks, this paper first proposes a deep learning classification model to recognize SO posts containing development knowledge. Second, to align filtered SO posts with programming language learning processes, this paper proposes a weakly supervised link approach to matching SO posts with chapters and sections of textbooks. The feature of weak supervision ensures that the approach can be easily extended to other textbooks. Based on these modules above, this paper implements the programming language learning service in the form of a Chrome plugin. We conduct experiments and user study. Their results demonstrate the effectiveness, scalability and stability of the service. © 2023 IEEE.

关键词： Textbooks

来源：评论

学校读者我要写书评

暂无评论

Pattern Analysis and Placement Optimization of the Four-horn Monopulse for Terahertz Communication

Pattern Analysis and Placement Optimization of the Four-horn...

引用

Cross Strait Quad-Regional Radio science and Wireless technology Conference (CSRWTC)

作者： Yong-Han Lu Zhong-bo Zhu Jing Ma Bin Shi Yu-ting Zhang Lin Peng Key Laboratory of Microwave and Optical Wave Application Technology Guilin University of Electronic Technology Guilin Guangxi China National Key Laboratory of Science and Technology on Space Microwave Xi'an China Science and Technology on Special System Simulation Laboratory Beijing Simulation Center Beijing China Guangxi Key Laboratory of Optoelectronic Information Processing School of Optoelectronic Engineering Guilin University of Electronic Technology Guilin China

The mobile node communication in terahertz monopulse system requires narrow beam to align with the mobile target precisely. In this paper, the radiation pattern of four-horn monopulse antenna is analyzed by use of the geometric optics (GO) and aperture field integration method (AFIM), and an efficient placement optimization to reduce the beamwidth of four-horn monopulse is presented. The optimization combines the genetic algorithm (GA) with GO-AFIM. The GA is employed to seek the optimal positions of the four horns, and the GO and AFIM are introduced into the fitness function of GA to evaluate the individual fitness. The optimization result has narrowed the beamwidth and enhanced gain of radiation pattern. Compared with the simulation in full wave software, the proposed method costs less time in pattern analysis and performs more efficiently in placement optimization.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Design of an Ultra-Wideband Low-Profile Directional Bowtie Antenna for Ground-Penetrating Radars

Design of an Ultra-Wideband Low-Profile Directional Bowtie A...

引用

International Conference on Microwave and Millimeter Wave technology Proceedings

作者： Jin Wu Jing Ma Bin Shi Kun-Shan Mo Lin Peng The Key Laboratory of Microwave and Optical Wave Application Technology Guilin University of Electronic Technology Guilin Guangxi China The Science and Technology on Special System Simulation Laboratory Beijing Simulation Center Beijing China School of Electronic Information and Automation Guilin University of Aerospace Technology Guilin Guangxi China

ISBN: (数字)9798350389968

ISBN: (纸本)9798350389975

In this paper, An elliptical patch dipole antenna with resistive loading and parasitic structure is proposed. By loading the parasitic structure, the height of the antenna is reduced. The overall dimensions of the antenna are $0.16\lambda_{0}\times 0.08\lambda_{0}\times 0.03\lambda_{0}$ , and $\lambda_{0}$ is the free-space wavelength at the lowest frequency. By loading large reflective floors, the proposed antenna achieves a good unidirectional radiation performance in the whole frequency band from 0.18 GHz to 2 GHz with a $\text{VSWR} < 2$ , and an in-band peak gain of up to 7.41 dBi is obtained. It is a good candidate antenna for ground-penetrating radar.

关键词： Microwave antennas Ground penetrating radar Dipole antennas Loading Bandwidth Millimeter wave radar Radar antennas

来源：评论

学校读者我要写书评

暂无评论

Study on Numerical simulation Method of Unsteady Deposition Characteristics of Particles in Surface Filtration 29

Study on Numerical Simulation Method of Unsteady Deposition ...

引用

2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Ma, Song Sun, Zhongning Zhou, Yanmin Gu, Haifeng Lintai Heilongjiang Provincial Key Laboratory of Nuclear Power System & Equipment Harbin Engineering University Harbin150001 China Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineering University Harbin150001 China

ISBN: (纸本)9780791886502

As an important part of the ventilation system of nuclear facilities, the performance of filter is of great significance to the environment and personnel safety. With the operation of the filter, the filtration mode will change from depth filtration to surface filtration. In this paper, a numerical simulation method is developed for the unsteady deposition characteristics of particles in the surface filtration. The parcel injection model is applied to accelerate the formation and growth process of dust cake on the surface of fiber filter. A series of subroutines running in FLUENT environment are developed to enhance the capabilities of computational fluid dynamics code in ANSYS. The Brownian force is added to the DPM model to calculate the particle trajectory more accurately. The function that aerosol particles are intercepted and deposited on the surface of fiber filter to form dust cake is added. The porous media model is used to simulate the fiber filter and dust cake. The porosity and resistance coefficient change with the unsteady deposition of particles. Combined with the subroutine with FLUENT software, a numerical simulation method which can be used to predict the unsteady deposition characteristics of particles in the surface filtration is formed. The numerical simulation results are compared with the experimental results, and they are basically consistent. So the developed numerical simulation method can be used to predict the unsteady deposition characteristics of particles in the surface filtration, and can also provide a theoretical basis for the structural design of pleated filter. © 2022 by ASME.

关键词： Deposition

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：