检索结果-内蒙古大学图书馆

Information and Communication Technology (ICTech), International Conference of

作者： Cong Wu Li Peng Zhang Dong Yu Shenyang Institute of Computing Technology Chinese Academy of Sciences University of Chinese Academy of Sciences Shenyang China Shenyang Institute of Computing Technology Chinese Academy of Sciences Shenyang CASNC Technology Co. Ltd. Shenyang China

ISBN: (数字)9798350376258

ISBN: (纸本)9798350376265

In order to solve the problem that sudden changes in velocity and acceleration at the corners of adjacent segments during high-speed machining of tiny line segments can lead to motor vibration and tool over-cutting, a machine trajectory monitoring and optimization method based on digital twin simulation and adaptive local polynomial interpolation algorithm is proposed. The digital twin simulation system is set up to monitor the trajectory and speed of the machine tool during machining, and the adaptive fifth degree polynomial is used to fit the corner trajectory when there is a sudden change of speed or acceleration at the corner of the machining trajectory, and then the curve interpolation is carried out by using the fitted curves, so as to improve the stability and accuracy of machining. In the experiment, a digital twin simulation system is established based on four elements of the Agent, and then the runtime data of the physical machine tool is collected through the protocol. Finally, the trajectory is optimized using the polynomial interpolation algorithm. A digital twin simulation system for Turn-milling machines is established to validate the functionality

关键词： Interpolation Optimization methods Machining approximation error approximation algorithms Polynomials Trajectory Digital twins Machine tools Monitoring

来源：评论

学校读者我要写书评

暂无评论

Parameterized Maximum Node-Disjoint Paths

arXiv

引用

arXiv 2024年

作者： Lampis, Michael Vasilakis, Manolis Université Paris-Dauphine PSL University CNRS UMR7243 LAMSADE Paris France

We revisit the Maximum Node-Disjoint Paths problem, the natural optimization version of the famous Node-Disjoint Paths problem, where we are given a graph G, k (demand) pairs of vertices (si, ti), and an integer , and are asked whether there exist at least vertex-disjoint paths in G whose endpoints are given pairs. This problem has been intensely studied from both the approximation and parameterized complexity point of view and is notably known to be intractable by standard structural parameters, such as tree-depth, as well as the combined parameter plus pathwidth. We present several results improving and clarifying this state of the art, with an emphasis towards FPT approximation. Our main positive contribution is to show that the problem's intractability can be overcome using approximation: We show that for several of the structural parameters for which the problem is hard, most notably tree-depth, the problem admits an efficient FPT approximation scheme, returning a (1 − Ε)-approximate solution in time f(td, Ε)nO(1). We manage to obtain these results by comprehensively mapping out the structural parameters for which the problem is FPT if is also a parameter, hence showing that understanding as a parameter is key to the problem's approximability. This, in turn, is a problem we are able to solve via a surprisingly simple color-coding algorithm, which relies on identifying an insightful problem-specific variant of the natural parameter, namely the number of vertices used in the solution. The results above are quite encouraging, as they indicate that in some situations where the problem does not admit an FPT algorithm, it is still solvable almost to optimality in FPT time. A natural question is whether the FPT approximation algorithm we devised for tree-depth can be extended to pathwidth. We resolve this negatively, showing that under the Parameterized Inapproximability Hypothesis no FPT approximation scheme for this parameter is possible, even in time f(pw, Ε)ng(Ε).

关键词： approximation algorithms

来源：评论

学校读者我要写书评

暂无评论

Cooperative Multicast for Multi-Connected XR Devices with Joint HARQ Processing

Cooperative Multicast for Multi-Connected XR Devices with Jo...

引用

IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Muhammad Ahsen Boyan Yanakiev Claudio Rosa Carles Navarro Manchon Ramoni Adeogun Department of Electronic Systems Aalborg University Aalborg Denmark Nokia Aalborg Denmark

ISBN: (数字)9798350362244

ISBN: (纸本)9798350362251

In this paper, we investigate the multi-connectivity for Extended Reality (XR) devices, having both a direct link and an indirect link to the same Next-Generation Node B (gNodeB). The indirect link is established through a cooperating 5th generation (5G) tethering device positioned in proximity to the XR device. Our study focuses on point-to-multipoint (PTM) multicast transmission to the XR device and the nearby 5G tethering device, emphasizing their cooperative interaction. We conduct this investigation under a spatially consistent channel model, quantifying the performance in terms of block error rate (BLER). Furthermore, we propose algorithms for processing joint hybrid automatic repeat request (HARQ) feedback (FB) in 5G multicast sessions. These algorithms are designed for multicast sessions, where User Equipment (UE)s actively cooperate, aiming to enhance the spectral efficiency of multiconnected XR devices by minimizing HARQ retransmissions. The resulting increase in spectral efficiency contributes to the overall capacity improvement of the network. Our link-level simulations demonstrate that multi-connectivity for XR yields a 0.8 dB gain for a 10% BLER target. Additionally, the proposed joint HARQ FB processing algorithm provides approximately a 7% gain in spectral efficiency.

关键词： Performance evaluation Multicast algorithms Spectral efficiency 5G mobile communication Unicast approximation algorithms User experience Gain Standards Signal to noise ratio

来源：评论

学校读者我要写书评

暂无评论

Study on the Iterative Estimation and Compensation Algorithm for IQ Imbalance in Coherent Optical Communication Systems

Study on the Iterative Estimation and Compensation Algorithm...

引用

International Conference on Fuzzy Systems and Knowledge Discovery (FSKD)

作者： Changjun Huang Fengtao He Xi'an University of Posts and Telecommunications Xi'an China

ISBN: (数字)9798350356328

ISBN: (纸本)9798350356335

Coherent optical communication technology is a key technology for building high-speed optical fibre communication networks, while the amplitude and phase imbalance between the in-phase and quadrature (IQ) signals at the receiving end will lead to the degradation of the received signal quality and affect the performance of the communication system. In this thesis, a narrowband zero-intermediate frequency (ZIF) receiver IQ imbalance estimation and compensation algorithm is proposed with the research objective of designing IQ imbalance estimation and compensation algorithms for the 16 quadrature amplitude modulation (16QAM) signal in coherent optical communication systems that can be implemented in hardware circuits. The algorithm is based on the Gram-Schmidt orthogonalization procedure (GSOP) for approximate estimation of the IQ imbalance parameters and improves the estimation accuracy of the IQ imbalance parameters by means of iterative optimization. The IQ imbalance signal is effectively compensated by the inverse matrix of the IQ mismatch parameter matrix. Based on the estimation error of the IQ imbalance parameters, the bit error rate (BER) of the signal transmission at different signal to noise ratio (SNR), and the simulation results of the 16QAM constellation diagram before and after compensation, it is concluded that the iterative optimized algorithm based on GSOP reduces the complexity of hardware implementation and improves the efficiency and accuracy of the IQ imbalance parameters estimation effectively. The findings of this study hold practical engineering significance for estimating and calibrating IQ imbalance in coherent optical communication systems using high-order modulated signals through digital signal processing techniques.

关键词： Accuracy Circuits Bit error rate Estimation Signal processing algorithms approximation algorithms Optical fiber communication Iterative algorithms Hardware Signal to noise ratio

来源：评论

学校读者我要写书评

暂无评论

Centroid-Guided YOLO for Plant Stem Detection in Digital Agriculture

Centroid-Guided YOLO for Plant Stem Detection in Digital Agr...

引用

International Symposium on Instrumentation Systems, Circuits and Transducers (INSCIT)

作者： Rogério Ballestrin Alexandre Balbinot Vitor Camargo Nardelli Ivan Müller Graduate Program in Electrical Engineering Universidade Federal do Rio Grande do Sul (UFRGS) Instituto SENAI de Inovação em Sistemas de Sensoriamento Competence Center For Digital Agriculture

ISBN: (数字)9798350350869

ISBN: (纸本)9798350350876

This study focuses on the utilization of a YOLO (You Only Look Once)-based object detection approach, along with the development of a customized algorithm, to address the identification and localization of invasive plant stems within agricultural crops. The initial phase involved the creation of a dataset comprising 485 manually annotated images, sourced from three distinct data repositories. Subsequent to this, the YOLO model underwent training to accurately recognize the plants depicted in the images. Following the model training, an algorithm was devised that leverages the centroid of the G vector in the RGB image as the designated point of interest for precise stem localization. The algorithm's effectiveness was assessed utilizing key metrics such as mean absolute error (MAE) and root mean square error (RMSE). For images sized at 600×600 pixels, the resulting MAE and RMSE values were calculated at 34.4 pixels and 46.8 pixels respectively. Notably, these outcomes underscored the necessity for refining the detection process, particularly in instances involving plants with delicate branches, where differentiation between the branch and the image back drop proved challenging. In terms of practical application within agrochemical dispersion systems, it was discerned that dispersion takes place across an application area rather than a singular point. By incorporating the proposed algorithm in conjunction with a dispersion cone aperture measuring $100\times 100$ pixels, it was projected that the dispersion system could effectively cover approximately 92.4% of the existing plants. This algorithmic approach exhibits the potential to curtail agrochemical dispersion by a substantial factor of up to 36 times, yielding economic and sustainability advantages through the reduction of waste and environmental contamination.

关键词： YOLO Training Location awareness Transducers Plants (biology) Agrochemicals approximation algorithms Vectors Sustainable development Dispersion

来源：评论

学校读者我要写书评

暂无评论

Discovering Denial Constraints in Dynamic Datasets

Discovering Denial Constraints in Dynamic Datasets

引用

International Conference on Data Engineering

作者： Eduardo H. M. Pena Fabio Porto Felix Naumann Federal University of Technology - Parana Brazil LNCC-DEXL Brazil Hasso Plattner Institute University of Potsdam Potsdam Germany

ISBN: (数字)9798350317152

ISBN: (纸本)9798350317169

Denial constraints (DCs) are data dependencies with high expressive power, offering great flexibility for modeling data quality rules. Specifying DCs manually is problematic, as the required domain expertise is expensive and scarce. Moreover, database updates can invalidate DCs thought to hold and simultaneously uncover new DCs. This fact leads to burdensome scenarios where experts must often revisit DC specifications. Several algorithms have been devised to discover DCs from data, among which only one considers DC discovery on data updates. However, that solution underperforms in many scenarios due to long runtime and excessive memory use. Also, it targets database inserts only, so no previous solution covers deletions. This paper proposes an efficient and flexible algorithm that covers the earlier limitations regarding performance and scope. The algorithm maintains small-footprint intermediate structures during database updates and a method that exploits the changes in this intermediate to update the DCs incrementally. The results of our extensive experimental evaluation show that our algorithm is orders of magnitude faster than the existing one, with much better scalability in the size of the data updates.

关键词： Runtime Databases Heuristic algorithms Scalability Data integrity Data engineering approximation algorithms

来源：评论

学校读者我要写书评

暂无评论

Chanced-Constrained Rolling-Horizon Optimization for the Green Hydrogen Microgrid System Operation

Chanced-Constrained Rolling-Horizon Optimization for the Gre...

引用

IEEE Region 10 International Conference TENCON

作者： Ha-yeong Cho Ho-jun Lee Jae-Hyung Lee Min-han Yoon dept. of Electric Engineering Kwangwoon University Seoul Korea Energy technology team Samsumg C&T City Korea

ISBN: (数字)9798350350821

ISBN: (纸本)9798350350838

In this paper, we introduce the problems with long-term period optimization of green hydrogen microgrid system operation and variability inherent in renewable energy. To solve the problems, we proposed a Rolling-Horizon Optimization(RHO) with Chanced-Constrained Optimization(CCO). The validity of our approach is confirmed by comparative analysis with conventional Mixed-Integer Linear Programming(MILP) scheduling by using real PV generation data.

关键词： Systems operation Green products Microgrids Green hydrogen Prediction algorithms approximation algorithms Scheduling Optimization IEEE Regions

来源：评论

学校读者我要写书评

暂无评论

Decentralized Cooperative Control for Multi-Reconfigurable Manipulator Based on Adaptive Dynamic Programing

Decentralized Cooperative Control for Multi-Reconfigurable M...

引用

Complex Systems and Intelligent Science (CSIS-IAC), International Annual Conference on

作者： Bo Dong Yu Cao Tianjiao An Xinyi He Hongbo Dong Bing Ma Department of Control Science and Engineering Changchun University of Technology Changchun China

ISBN: (数字)9798331504755

ISBN: (纸本)9798331504762

This paper proposes a decentralized cooperative control for multi-reconfigurable manipulator (MRM) based on Adaptive Dynamic Programing (ADP). The control method can achieve both motion path tracking and control the force between the manipulator and the controlled object. The dynamic model of reconfigurable manipulator and controlled object is established using the Newton-Euler algorithm and load distribution. When facing unknown terms in the model, radial basis function neural network (RBFNN) is used for approximation. By taking advantage of the ADP algorithm to obtain the optimal control strategy. The closed-loop MRM system is proved to be stable by using the Lyapunov theory. Finally, the effectiveness of the control method is verified through numerical simulation.

关键词： Adaptation models Tracking Heuristic algorithms Dynamics Optimal control Radial basis function networks approximation algorithms Numerical models Manipulator dynamics Load modeling

来源：评论

学校读者我要写书评

暂无评论

Real-Time UWB and IMU Fusion Positioning System for Urban Rail Transit with High Mobility

Real-Time UWB and IMU Fusion Positioning System for Urban Ra...

引用

IEEE Conference on Vehicular Technology (VTC)

作者： Rongjing Wang Hanli Jiang Qianqian Zhang Gang Liu Fei Richard Yu Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu China Depart. of Systems and Computer Eng. Carleton University Ottawa ON Canada

ISBN: (数字)9798350387414

ISBN: (纸本)9798350387421

Urban rail transit is currently moving toward automated driving and mobile occlusion, which raises higher expectations for the train positioning system. Operating in diverse environments like open spaces and tunnels, a single positioning system falls short in meeting the accuracy and consistency requirements for train positioning along the entire rail line. In response to these stringent requirements, this research proposes an Error-State Kalman Filter (ESKF) based real-time fusion train positioning system for urban rail transit, incorporating Ultra-Wideband (UWB) and Inertial Measurement Unit (IMU) technologies. Through practical measurements, an UWB ranging error model is established. Based on this model, a simulation study is conducted on the proposed real-time fusion positioning algorithm under different UWB anchor deployment methods in the context of urban rail transit scenarios. The real-time performance and accuracy of the proposed algorithm were validated through in-tunnel testing.

关键词： Rails Vehicular and wireless technologies Accuracy Simulation Position measurement approximation algorithms Real-time systems

来源：评论

学校读者我要写书评

暂无评论

Does Machine Bring in Extra Bias in Learning? Approximating Fairness in Models Promptly

arXiv

引用

arXiv 2024年

作者： Bian, Yijun Luo, Yujie College of Design and Engineering National University of Singapore Singapore Department of Mathematics National University of Singapore Singapore

Providing various machine learning (ML) applications in the real world, concerns about discrimination hidden in ML models are growing, particularly in high-stakes domains. Existing techniques for assessing the discrimination level of ML models include commonly used group and individual fairness measures. However, these two types of fairness measures are usually hard to be compatible with each other, and even two different group fairness measures might be incompatible as well. To address this issue, we investigate to evaluate the discrimination level of classifiers from a manifold perspective and propose a "harmonic fairness measure via manifolds (HFM)" based on distances between sets. Yet the direct calculation of distances might be too expensive to afford, reducing its practical applicability. Therefore, we devise an approximation algorithm named "approximation of distance between sets (ApproxDist)" to facilitate accurate estimation of distances, and we further demonstrate its algorithmic effectiveness under certain reasonable assumptions. Empirical results indicate that the proposed fairness measure HFM is valid and that the proposed ApproxDist is effective and *** Codes 68T01, 68T09, 68T20 Copyright © 2024, The Authors. All rights reserved.

关键词： approximation algorithms

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：