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arXiv 2021年

作者： Jia, Xiang-Yu Liu, Er-Jian Chen, Chun-Yan Yan, Xiao-Yong Key Laboratory of Transport Industry of Big Data Application Technologies for Comprehensive Transport Ministry of Transport Beijing Jiaotong University Beijing100044 China Institute of Transportation System Science and Engineering Beijing Jiaotong University Beijing100044 China Traffic Control Technology Co. Ltd Beijing100875 China

Measuring the interaction between cities is an important research topic in many disciplines, such as sociology, geography, economics and transportation science. The traditional and most widely used spatial interaction model is the gravity model, but it requires the parameters to be artificially set. In this paper, we propose a parameter-free interactive city choice (ICC) model that measures intercity interaction from the perspective of individual choice behavior. The ICC model assumes that the probability of an individual choosing to interact with a city is proportional to the number of opportunities in the destination city and inversely proportional to the number of intervening opportunities between the origin city and the destination city, calculated using the travel time in the transportation network. The intercity interaction intensity can be obtained by calculating the product of this probability and the origin city's population. We apply the ICC model to measure the interaction intensity among 339 cities in China and analyze the impact of changes in the Chinese land transportation network from 2005 to 2018 on the intercity and city interaction intensity. Compared with the previously widely used spatial interaction models, the measurement results of the ICC model are more consistent with the actual situation. © 2021, CC BY.

关键词： Travel time

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Multiple Anti-windup Loops under Multiple Activations:Dynamic Case to Enlarge Domain of Attraction

Multiple Anti-windup Loops under Multiple Activations:Dynami...

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第三十二届中国控制会议

作者： Xiongjun Wu Ziyang Meng The 802 Institute of Shanghai Academy of Space Flight Technology The Eighth Academy of China Aerospace Science and Technology Corporation Department of Automation Shanghai Jiao Tong Universityand Key Laboratory of System Control and Information ProcessingMinistry of Education of China ACCESS Linnaeus Centre School of Electrical EngineeringRoyal Institute of Technology

ISBN: (纸本)9781479900305

A multiple anti-windup loops under multiple dynamic activations strategy is proposed to enlarge the domain of attraction. This work is parallel to the multiple activation case with static *** traditional anti-windup compensator is activated immediately as the saturation *** was shown recently that,by delaying the activation of the anti-windup mechanism to a certain level,the performance can be improved for the closed-loop *** was further shown that better performance can be obtained by activating an anti-windup mechanism in anticipation of actuator saturation,in comparison with the delayed activation *** paper considers the anti-windup design problem of enlarging domain of attraction under a dynamic multiple activation *** this multiple activation scheme,the anticipatory,delayed and immediate activation mechanism is incorporated in the same framework simultaneously.A furthermore significant performance improvements over both the immediate and delayed activation schemes can be *** proposed dynamic multiple activation scheme established a unified anti-windup framework and can be readily extended to the traditional immediate,delayed and anticipatory activation anti-windup mechanisms.

关键词： Anti-windup dynamic compensator domain of attraction multiple activations

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Comparative Molecular Transformations of Dissolved Organic Matter Induced by Chlorination and Ammonia/Chlorine Oxidation Process

SSRN

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SSRN 2023年

作者： Ye, Bei Song, Zhi-Min Wu, De-Xiu Liang, Jun-Kun Wang, Wen-Long Hu, Wei Yu, Yang Shenzhen Key Laboratory of Ecological Remediation and Carbon Sequestration Environmental Protection Key Laboratory of Microorganism Application and Risk Control Institute of Environment and Ecology Shenzhen International Graduate School Tsinghua University Shenzhen518055 China Key Laboratory of Microorganism Application and Risk Control of Shenzhen Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety Shenzhen International Graduate School Tsinghua University Shenzhen518055 China Department of Environmental Engineering Graduate School of Engineering Kyoto University Kyoto6158540 Japan Pingshan District Urban Management and Law Enforcement Bureau Shenzhen518118 China Department of Earth System Science Tsinghua University Beijing100084 China

The ammonia/chlorine oxidation process can greatly degrade PPCPs in water. However, its effect on molecular transformations of natural organic matter (NOM) and effluent organic matter (EfOM) are still poorly understood. In this study, molecular transformations of NOM and EfOM occurring during ammonia/chlorine were explored and compared with those occurred during chlorination, using spectroscopy and mass spectrometry. Phenolic and highly unsaturated aliphatic compounds together with aliphatic compounds were found to be predominant in both NOM and EfOM samples, all of which were significantly degraded after two processes. The ammonia/chlorine process led to greater decreases in the molecular weights of such components but lower reductions in aromaticity. Compared with chlorination, ammonia/chlorine was found to be more likely to degrade compounds while remaining fluorophores or chromophores. The CH(N)O(S) precursors were found to be similar for both processes but their products were quite different. The CH(N)O(S) precursors that only found in ammonia/chlorine had higher molecular weights and greater degrees of oxidation but lower degrees of saturation. In contrast, the unique CH(N)O(S) products that only found in ammonia/chlorine exhibited lower molecular weights and lower degrees of oxidation degrees together with higher degrees of saturation. Lower total abundance of chlorinated byproducts was found by ammonia/chlorine compared with chlorination, although the former process provided a richer diversity. In all water samples, chlorinated byproducts were mainly generated by substitution reactions during ammonia/chlorine and chlorination. Overall, the findings of this study could provide new insights into the transformations of NOM and EfOM induced by ammonia/chlorine and chlorination. © 2023, The Authors. All rights reserved.

关键词： Ammonia

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Uplink Performance of Cell-Free Extremely Large-Scale MIMO systems

arXiv

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arXiv 2023年

作者： Lei, Hao Wang, Zhe Xiao, Huahua Zhang, Jiayi Ai, Bo School of Electronic and Information Engineering Beijing Jiaotong University Beijing100044 China Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University Beijing100044 China ZTE Corporation State Key Laboratory of Mobile Network and Mobile Multimedia Technology State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing100044 China

In this paper, we investigate the uplink performance of cell-free (CF) extremely large-scale multiple-input-multiple-output (XL-MIMO) systems, which is a promising technique for future wireless communications. More specifically, we consider the practical scenario with multiple base stations (BSs) and multiple user equipments (UEs). To this end, we derive exact achievable spectral efficiency (SE) expressions for any combining scheme. It is worth noting that we derive the closed-form SE expressions for the CF XL-MIMO with maximum ratio (MR) combining. Numerical results show that the SE performance of the CF XL-MIMO can be hugely improved compared with the small-cell XL-MIMO. It is interesting that a smaller antenna spacing leads to a higher correlation level among patch antennas. Finally, we prove that increasing the number of UE antennas may decrease the SE performance with MR combining. Copyright © 2023, The Authors. All rights reserved.

关键词： MIMO systems

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Aircraft Autonomous Positioning Based on a Coarse to Fine Multi-modal Image Registration Scheme

Aircraft Autonomous Positioning Based on a Coarse to Fine Mu...

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Power Electronics, Computer Applications (ICPECA), IEEE International Conference on

作者： Fangde Sun Wenxing Fu Xiaohui Lu Jing Dong Songlai Han School of Aeronautics and Astronautics Central South University Changsha China Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing China People’s Liberation Army 91039th Unit Beijing China Aerospace Science and Engineering National University of Defense Technology Changsha China

ISBN: (数字)9781728190044

ISBN: (纸本)9781728190051

In this paper, an autonomous positioning method based on coarse-to-fine multi-modal image matching is proposed for UAV navigation in GPS denied environment. Coarse image matching refers to roughly determining the approximate position of the real-time image in the reference image. Fine image matching refers to iterative matching around the position obtained by coarse image matching to achieve more accurate matching results. Besides, RANSAC is adopted to eliminate the outliers of image matching. After getting the result of image matching, we use PNP to estimate the position of the aircraft. The proposed position method has the advantages of high accuracy and reliability. The experimental results show that the average error of the position of the proposed method is 59%.

关键词： Image registration Image matching Aerospace electronics Real-time systems Power electronics Reliability Aircraft

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The Design and Research of Resistance Instrument in Ship Towing Test

The Design and Research of Resistance Instrument in Ship Tow...

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IEEE International Conference on Mechatronics and Automation

作者： Nan Li Nan Liu Xueqi Zhang Chao Cui National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin University of Technology Tianjin China Tianjin Baolai Precision Machinery Industry Group Co. Ltd Tianjin China

ISBN: (数字)9798350388077

ISBN: (纸本)9798350388084

Based on the requirements of ship resistance towing test, a strain gauge type of resistance instrument has been designed, which consisting of the frame, towing component, course component, measuring component, etc. The towing component is responsible for the towing movement of the ship model, and the course component is responsible for constructing different course angles in the test requirements. An automatic brake mechanism has been equipped in measuring component, which can ensure the stability and accuracy of the tension sensor in towing test. The strength limit on the key components of the resistance instrument has been calculated by finite element analysis software, the optimization has been used in vulnerable components, and the instrument strength and reliability has been insured in the test.

关键词： Resistance Instruments Force Strain measurement Stability analysis Finite element analysis Electrical resistance measurement

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control of General Linear Time-Delay systems: Applications of the Kronecker-Seuret Decomposition

arXiv

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arXiv 2022年

作者： Feng, Qian Zheng, Wei Xing Xiao, Feng Wang, Xiaoyu School of Control and Computer Engineering North China Electric Power University Beijing China School of Computer Data and Mathematical Sciences Western Sydney University Sydney Australia State Key Laboratory of Alternative Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing China

We consider the design of stabilizing feedback controllers for autonomous linear time-delay system ẋ(t) = Xi=0ν Aix(t − ri) + Z−0r Ae(τ)x(t + τ)dτ + Xi=0ν Biu(t − ri) + Z−0r Be(τ)u(t + τ)dτ + D1w(t), z(t) = Xi=0ν Cix(t − ri) + Z−0r Ce(τ)x(t + τ)dτ + Xi=0ν Biu(t − ri) + Z−0r Be (τ)u(t + τ)dτ + D2w(t), x(t0 + θ) = ψ(θ), ∀θ ∈ [−r, 0], r = rν > · · · > r2 > r1 > r0 = 0, ν ∈ N under dissipative constraints expressed by quadratic forms, where matrix-valued functions Ae(·), Ce(·), Be(·), Be (·) can contain finite but unbounded number of square integrable functions. Our result is derived from an application of the Kronecker-Seuret decomposition in conjunction with the construction of Krasovskiı̆ functionals, where the final solution is expressed as a set of convex semidefinite programming problems. All functions in Ae(·), Ce(·), Be(·), Be (·) are explicitly addressed without requiring the use of operator or C0-semigroup theory. Moreover, the resulting optimization sufficient conditions can be efficiently computed by numerical solvers that are accessible to the general public, without requiring that the stabilizability and detectability of the open-loop system are known. We present the test results of two challenging examples, which could not be efficiently tackled by existing methods, to demonstrate the effectiveness of our methodology. The main objective of this study is to develop a non-conservative and numerically efficient framework for the mathematical control problem under investigation, designed to be accessible to engineers without expertise in operator theory and functional analysis. Additionally, this article briefly reviews recent research advancements in the mathematical control of linear time-delay systems, which could be useful to both emerging and experienced researchers in this field. Copyright © 2022, The Authors. All rights reserved.

关键词： State feedback

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Voxel based treatment prediction using diffusion anisotropy indices and spatial information in Glioblastoma Multiform tumor

Voxel based treatment prediction using diffusion anisotropy ...

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Iranian Conference of Biomedical engineering (ICBME)

作者： Hadi Sabahi Hamid Soltanian-Zadeh Lisa Scarpace Tom Mikkelsen Control and Intelligent Processing Center of Excellence School of Electrical and Computer Engineering University of Tehran Tehran Iran Image Analysis Laboratory Radiology Department Henry Ford Hospital Detroit MI USA Hermelin Brain Tumor Research Center Neurosurgery Department Henry Ford Health System Detroit MI USA

In this paper, we propose a method to predict the outcome of Bevacizumab therapy on Glioblastoma Multiform (GBM) tumors. The method uses diffusion anisotropy indices (DAI) and spatial information to predict the treatment response of each tumor voxel. These DAIs are Fractional Anisotropy, Mean Diffusivity, Relative Anisotropy, and Volume Ratio, extracted from Diffusion Tensor Imaging (DTI) data before treatment. The spatial information is considered as the distance of each tumor voxel from the tumor center, extracted from pre-treatment post-contrast T1-weighted Magnetic Resonance Images (pc-T1-MRI). DAIs and spatial information of each tumor voxel are considered as feature vector. DTI and pc-T1-MRI are gathered before and after the treatment of seven GBM patients. First, DAIs of all brain voxels and the distance of each tumor voxel from the tumor center are calculated. Second, the method registers pre-treatment DAI maps and post-treatment pc-T1-MRI to pre-treatment pc-T1-MRI. Next, the tumor is segmented using thresholding technique from pc-T1-MRI. Then, Gd-enhanced voxels of the pre- and post-treatment pc-T1-MRI are compared to label the feature vectors. Three classifiers were evaluated, including Support Vector Machine, K-Nearest Neighbor, and Artificial Neural Network. Classification results show a preference for K-Nearest Neighbor based on well-established performance measures.

关键词： Tumors Anisotropic magnetoresistance Diffusion tensor imaging Support vector machines Feature extraction Artificial neural networks

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On-chip ultra-compact hexagonal boron nitride topological ring-resonator in visible region

arXiv

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arXiv 2022年

作者： Wu, Min Yang, Yibiao Fei, Hongming Lin, Han Zhao, Xiaodan Kang, Lijuan College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Taiyuan030024 China Centre for Translational Atomaterials Faculty of Science Engineering and Technology Swinburne University of Technology HawthornVIC3122 Australia

Ultra-compact topological ring-resonators with chirality are important devices for quantum optics. However, there are limited demonstrations of chiral resonators, especially in the visible region. We proposed a topological photonic ring-resonator based on hexagonal boron nitride (hBN) valley photonic crystal (VPC). The spin-valley locking effect in VPC allows achieving robust unidirectional transmission of edge states in the visible region (600 nm-650 nm). As a result, a high quality factor (679.3) with a free spectral range of 15.2 nm in the visible region can be achieved in a hBN all-pass filter with a compact size (2.1 μm∗1.8 μm). In addition, we investigated the transmission properties of hBN ring-resonators with different shapes and combinations, confirming the flexibility of designing topological ring-resonators based on this principle. This design can be readily integrated with quantum photonic chips for broad applications. Copyright © 2022, The Authors. All rights reserved.

关键词： Photonic crystals

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Cloud identification model for sky images based on Otsu

Cloud identification model for sky images based on Otsu

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International Conference on Renewable Power Generation (RPG 2015)

作者： Hongping Li Fei Wang Hui Ren Hongbin Sun Chun Liu Bo Wang Jing Lu Zhao Zhen Xiaoli Liu State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources (North China Electric Power University) Baoding 071003 Hebei Province China State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment (Department of Electrical Engineering Tsinghua University) Haidian District Beijing 100084 China China ElectricPowerResearch Institute HaidianDistrict Beijing 100192 China

Irradiance changes caused by clouds movement are the main factors, which lead to mutation of photovoltaic power. In order to increase the accuracy of the ultra-short-term photovoltaic power prediction, based on of clouds images, the cloud identification for sky images is one of the primary aspects for improving photovoltaic power accuracy. A cloud identification model for sky images is established based on Otsu. Firstly, a series of sky images are collected by Total Sky Imager (TSI) with the regions of clouds and sky are distinguished. Secondly, the color features (based on RGB values) of pixels in sample images and the spectral and texture features of the whole image are extracted; Finally, we established a cloud identification model for sky images based on Otsu according to the clouds' and sky areas' division and the general characteristics featured by pixels and images. The simulated results show that the model in this paper can identify the clouds in a sky images effectively.

关键词： Otsu cloud identification texture threshold Clouds sky images texture textures pixel

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