检索结果-内蒙古大学图书馆

Informatics, Networking and Computing (ICINC), International Conference on

作者： Miao Tian Peixuan Li Wenbo Song Jieping Xu Science and Technology on Complex Electronic System Simulation laboratory Space Engineering University Beijing China

Photometry is an important optical characteristic of space targets. Due to the huge computational volume of the photometry of the full-angle of a space target, the computation time is long and is difficult to meet the realistic demand. In this study, a Gearman based distributed parallel computation framework is constructed to automatically decompose and distribute the photometry computation tasks, automatically balance the computational load, and compose the computational results. This method divides the target photometry calculation into four independent variables, conducts distributed parallel calculation respectively, and finally integrates the calculation results into single target photometry information. The distributed parallel photometry computation method based on Gearman framework is important for fast computation of full-angle photometry data of space targets and assisting space target situational awareness tasks.

关键词： Integrated optics Distributed databases Optical variables control Task analysis Informatics Photometry

来源：评论

学校读者我要写书评

暂无评论

Research on Multi-Satellite Mission Planning Based on Improved Genetic Algorithm

Research on Multi-Satellite Mission Planning Based on Improv...

引用

Computer science and Management technology (ICCSMT), International Conference on

作者： Yang Yang Desheng Liu Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing China

For the multi-satellite mission planning problem, a multi-satellite mission planning model is constructed by considering the constraints of satellite’s visibility window to the target, attitude transition, storage and energy consumption, and an improved genetic algorithm is proposed to solve the model. The algorithm adopts the real number coding method to improve the solution efficiency, introduces the adaptive mechanism and the elite retention strategy, which improves the problems that the genetic algorithm is easy to fall into local optimum and converge early. The effectiveness of the improved genetic algorithm for solving multi-star mission planning is verified through simulation case analysis, and it is compared and analyzed with the standard genetic algorithm. The results show that the well genetic algorithm can achieve faster convergence and better planning results, and has better adaptability to large-scale mission planning problems.

关键词：

来源：评论

学校读者我要写书评

暂无评论

NWD-YOLOv5: A YOLOv5 Model for Small Target Detection Based on NWD Loss

NWD-YOLOv5: A YOLOv5 Model for Small Target Detection Based ...

引用

Robotics, Intelligent Control and Artificial Intelligence (RICAI), International Conference on

作者： Liliang Zhou Huaming Ran Rongling Xiong Ruijie Tan National Key Laboratory of Complex Aviation System Simulation Chengdu China The 10th Research Institute of China Electronics Technology Group Corporation Chengdu China School of Mathematics Southwest Jiaotong University Chengdu China

ISBN: (数字)9798331541699

ISBN: (纸本)9798331541705

Target detection technology is vital in modern social management and urban security, with small target detection— accurately identifying tiny objects in large scenes—posing a key challenge for improving surveillance system accuracy and real-time performance. The YOLO series is still the mainstream target detection model, for the YOLOv5 model, as the IoU metric it adopts still uses the geometrical overlap of the detection frame as the basis of the loss calculation, while the experiments have proved that this metric is unable to effectively utilize the small-scale characteristics of small targets. Therefore, improving the loss metric in the existing framework can help the model to pay more attention to the spatial semantic features of small targets in the image in the training phase of the network, respectively, and thus improve the detection effect. In this paper, we propose the NWD-YOLOv5 model, i.e., we introduce the NWD loss that measures the difference in the distribution of the detection frames for the existing target detection framework YOLOv5, which ensures that the loss of the small targets is not neglected in the calculation of the forward propagation loss of the model, and we purposefully modify the structure of the feature extraction network in the original framework by adding a feature extraction layer for the detection of the small targets, which enhances the ability of the model to capture the subtle features thus improving the accuracy of small target detection. Through comparative experiments, we evaluated the detection performance of the original YOLOv5 model, the YOLOv5 model using only the NWD loss, the YOLOv5 model with only the additional small-target detection layer, and the full NWD-YOLOv5 model for small-targeted human bodies on the screened COCO2017 public dataset, respectively. The experimental results show that compared to the original YOLOv5 model, the model with only the NWD loss improves the mAP@.5 metrics on small-target detection by 16

关键词： YOLO Training Analytical models Accuracy Surveillance Semantics Feature extraction Propagation losses Loss measurement Security

来源：评论

学校读者我要写书评

暂无评论

Exploration of the application of optimisation algorithm using stochastic gradient descent method in satellite resource allocation

引用

Applied Mathematics and Nonlinear sciences 2024年第1期9卷

作者： Zhao, Demin Xiong, Wei Shi, Jinjing Science and Technology on Complex Electronic System Simulation Laboratory University of Aerospace Engineering Beijing101400 China Dfh Satellite CO. Ltd Beijing100080 China North Automatic Control Technology Institute Shanxi Taiyuan030006 China

With the popularization and development of communication technology, the resource allocation problem of satellites has become a hot research topic. This study proposes a model for satellite resource allocation through the development of a beam mobilization system model and problem modeling. Then, on the basis of the linear stochastic gradient descent method, the classification accuracy of the algorithm is improved by adjusting the algorithm-solving method. Then its weight assignment method is improved to get the improved weighted linear stochastic gradient descent method. Using the optimized weighted linear stochastic gradient descent method to solve the satellite resource allocation problem from the perspective of the original problem, a model based on IWLSGD is designed and tested for performance. Through simulation experiments, the beam allocation service value of the satellite resource allocation model in this paper is 193, which is 4.32% and 3.21% higher than that of LSGD and WLSGD, respectively, and iterative convergence is faster, and its operation time and service value performs the best under different numbers of communication time slots. The system revenue, system access success rate, and system satisfaction under the interference environment between LEO and GEO are maintained at 15208, 0.8~1.0, and 85%, and keep around 7500, 1, and 75% under 5G base station interference. The satellite resource allocation model in this paper can effectively improve the utilization efficiency of communication resources and better adapt to dynamically changing interference scenarios. © 2024 Demin Zhao et al., published by Sciendo.

关键词： Resource allocation

来源：评论

学校读者我要写书评

暂无评论

基于晶体塑性的辐照金属材料局部化颈缩和吕德斯带的模拟研究

引用

Acta Mechanica Sinica 2023年第4期39卷 132-146页

作者：付家琪刘文斌隋昊男程杨洋段慧玲 State Key Laboratory for Turbulence and Complex System Department of Mechanics and Engineering ScienceThe Beijing Innovation Center for Engineering Science and Advanced TechnologyCollege of EngineeringPeking UniversityBeijing100871China Key Laboratory of High Energy Density Physics Simulation Center for Applied Physics and Technologyand Inertial Fusion Sciences and ApplicationsCollaborative Innovation Center of Ministry of EducationPeking UniversityBeijing100871China

金属材料中,颈缩失稳通常由表面缺陷或材料不均匀性等潜在扰动引起并随着微结构的演化进一步发展.本文将构型扰动法与考虑辐照效应的晶体塑性本构关系相结合,模拟了辐照前后局部化颈缩和吕德斯带等现象.通过考虑模拟局部化变形中扰动的... 详细信息

金属材料中,颈缩失稳通常由表面缺陷或材料不均匀性等潜在扰动引起并随着微结构的演化进一步发展.本文将构型扰动法与考虑辐照效应的晶体塑性本构关系相结合,模拟了辐照前后局部化颈缩和吕德斯带等现象.通过考虑模拟局部化变形中扰动的必要性,发现了外在的几何缺陷和内禀的微结构演化在颈缩过程中的竞争关系.此外,以纯金属铜和奥氏体不锈钢为例研究了辐照硬化效应对颈缩失稳的影响.结果表明,流动应力的增加和功硬化能力的降低是均匀延伸率下降的原因,辐照效应导致的织构软化作用可以忽略.为了解释辐照后低碳钢下屈服点和吕德斯应变同时增加的现象,一种位错脱钉扎和位错与辐照缺陷的交互作用相耦合的塑性变形机制被提出并结合修正的流动方程,很好地模拟出包含屈服下降、应力平台、应变扩展和应变硬化等特征的吕德斯带现象.其中,位错与辐照缺陷的相互作用也可以解释辐照后纯金属材料中发现的扩散颈缩现象.我们的模拟结果既阐明了几何缺陷在颈缩失稳中的重要作用,也为辐照金属中常见的宏观塑性失稳现象提供了清晰的物理图像.

关键词：吕德斯带金属材料奥氏体不锈钢晶体塑性下屈服点流动应力几何缺陷均匀延伸率

来源：评论

学校读者我要写书评

暂无评论

GPIO Based Iterative Learning Control for Manipulators with Time-Varying Disturbances 42

GPIO Based Iterative Learning Control for Manipulators with ...

引用

42nd Chinese Control Conference, CCC 2023

作者： Lu, Huangyuwei Wang, Zuo Sun, Jiankun Xiao, Xi Li, Shihua School of Automation Southeast University Nanjing210096 China Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of Education Nanjing210096 China Shenzhen Research Institute Southeast University Shenzhen518063 China School of Artificial Intelligence and Automation Huazhong University of Science and Technology Wuhan430074 China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing211106 China

ISBN: (纸本)9789887581543

To improve the disturbance rejection ability and repetitive tracking accuracy of manipulators, a composite iterative learning control (ILC) scheme via generalized proportional integral observer (GPIO) is proposed. A high-order polynomial is first employed to model the time-varying disturbances that include unmodeled dynamics, parameter uncertainties and load fluctuations. A GPIO is then designed to estimate the disturbances and high-order time derivatives. By introducing estimations into a PD-type ILC at each iteration, a composite control scheme is obtained, such that the undesirable influence of time-varying disturbances can be effectively attenuated in the repetitive tracking process of manipulators. In this paper, the rigorous stability analysis of the closed-loop system is presented to guarantee that the tracking error exponentially converges to zero as the iteration number tends to infinity. The effectiveness of the proposed control scheme is finally verified by simulation results. © 2023 Technical Committee on Control Theory, Chinese Association of Automation.

关键词： Disturbance rejection

来源：评论

学校读者我要写书评

暂无评论

Differentiable Neural Architecture Search for Domain Adaptation in Fault Diagnosis

SSRN

引用

SSRN 2023年

作者： Liu, Yumeng Li, Xudong Hu, Yang Institute of Software Chinese Academy of Sciences Beijing China University of Chinese Academy of Sciences Beijing China Jingdong Industry Beijing China Science and Technology on Complex Aviation System Simulation Laboratory 9236 mailbox Beijing China

In recent years, deep transfer learning has been widely applied in fault diagnosis. In particular, domain adaptation method to solve unsupervised transfer learning problem has become a research hotspot. However, these researches mainly focus on the construction of loss function, and the design of network structure still depends on manual work. A differentiable neural architecture search method is proposed to automatically search for network structures suitable for domain adaptation in fault diagnosis to solve this problem. The proposed method search for two components in the Inception search space: structures of Inception blocks and feature mask. Inception blocks are stacked to form a complete network, and the feature mask selects the features for domain adaptation. Besides, to improve the search efficiency, we search and adapt multiple target domains at the same time, expanding the application scenarios of domain adaptation. The proposed method is evaluated on two datasets, and experiments show that this method can generate networks with excellent performance. © 2023, The Authors. All rights reserved.

关键词： Failure analysis

来源：评论

学校读者我要写书评

暂无评论

A coevolutionary framework of business-IT alignment via the lens of enterprise architecture

引用

Journal of systems Engineering and Electronics 2020年第5期31卷 983-995页

作者： LIN Menglong YI Shuanghui ZHANG Mengmeng CHEN Tao CHEN Honghui ZHANG Xiaoxue Science and Technology on Information Systems Engineering Laboratory National University of Defense TechnologyChangsha 410072China National Key Laboratory for Complex System Simulation Academy of Military SciencesBeijing 100000China

Due to the turbulent external business environment, the complexity of internal relations of the organization and the emergence of subversive IT roles, the business-IT alignment(BITA)has become increasingly difficult. The unsuccessful realization of BITA will lead to the waste of organizational resources, the reduction of return on investment and eventually the loss of competitive advantage. In recent years, coevolution has received widespread attention due to its ability to describe the dynamic relationship between IT and business. Multiple principles such as quickening learning action loops and adopt suitable organizing principles for achieving business and IT coevolution(BITC) are obtained. However, the continuous BITC is still hard to be achieved because of the lack of complete BITC management. This paper focuses on the management process of the BITC and how to perform it gradually. A coevolution framework combines the enterprise architecture(EA) approach with the coevolution analysis is proposed, which contains the design of EA, the sensing and governance of the misalignment and the procedure of the EA misalignment *** steps for the governance and prevention of misalignment are discussed in particular. Through comparison with the principles,characteristics and methods of coevolution in the literature, the proposed framework is evaluated. The results show that the proposed framework is effective for BITC implementation.

关键词： business-IT alignment(BITA) coevolution misalignment governance misalignment prevention enterprise architecture

来源：评论

学校读者我要写书评

暂无评论

A LSTM-based method for simulation execution validity evaluation 33

A LSTM-based method for simulation execution validity evalua...

引用

33rd European Modeling and simulation Symposium, EMSS 2021

作者： Wang, YuLun Li, Wei Li, Jing Control and Simulation Center Harbin Institute of Technology Harbin150080 China Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing100074 China

This paper improves the concept of simulation execution validity and a methodology to assess the complex simulation system. As the complexity of the simulation system gradually rises, the magnitude of the simulation data obtained continues to increase, which makes it extremely difficult for experts to provide expert knowledge to evaluate the execution validity of the simulation system. More precisely, the essence of execution validity is to dig out the hidden relationships in the simulation time series data and complete the classification task whether it is valid. Considering that machine learning can better complete the two tasks of mining data features and classification, this paper adopts long short-term memory, a neural network used to process time series data, to evaluate the execution validity. Finally, an experiment is conducted on a simulation system, and the results show that the evaluation method based on LSTM can accurately evaluate the validity of the simulation system, and can greatly improve the efficiency of evaluation. © 2021 The Authors.

关键词： Long short-term memory

来源：评论

学校读者我要写书评

暂无评论

Multi-step Temporal Modeling for UAV Tracking

arXiv

引用

arXiv 2024年

作者： Yuan, Xiaoying Xu, Tingfa Liu, Xincong Wang, Ying Qin, Haolin Fang, Yuqiang Li, Jianan Beijing Institute of Technology Beijing100081 China The Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing101416 China The Key Laboratory of Photoelectronic Imaging Technology and System Ministry of Education of China Beijing100081 China Chongqing Innovation Center Beijing Institute of Technology Chongqing401135 China

In the realm of unmanned aerial vehicle (UAV) tracking, Siamese-based approaches have gained traction due to their optimal balance between efficiency and precision. However, UAV scenarios often present challenges such as insufficient sampling resolution, fast motion and small objects with limited feature information. As a result, temporal context in UAV tracking tasks plays a pivotal role in target location, overshadowing the target’s precise features. In this paper, we introduce MT-Track, a streamlined and efficient multi-step temporal modeling framework designed to harness the temporal context from historical frames for enhanced UAV tracking. This temporal integration occurs in two steps: correlation map generation and correlation map refinement. Specifically, we unveil a unique temporal correlation module that dynamically assesses the interplay between the template and search region features. This module leverages temporal information to refresh the template feature, yielding a more precise correlation map. Subsequently, we propose a mutual transformer module to refine the correlation maps of historical and current frames by modeling the temporal knowledge in the tracking sequence. This method significantly trims computational demands compared to the raw transformer. The compact yet potent nature of our tracking framework ensures commendable tracking outcomes, particularly in extended tracking scenarios. Comprehensive tests across four renowned UAV benchmarks substantiate the superior efficacy of our approach, delivering real-time performance at 84.7 FPS on a single GPU. Real-world test on the NVIDIA AGX hardware platform achieves a speed exceeding 30 FPS, validating the practicality of our method. Copyright © 2024, The Authors. All rights reserved.

关键词： Unmanned aerial vehicles (UAV)

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：