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CBSC: A Crowdsensing System for Automatic Calibrating of Barometers

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Journal of Computer science & Technology 2019年第5期34卷 1007-1019页

作者： Hai-Bo Ye Xuan-Song Li Li Sheng Kai Dong College of Computer science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100China School of Computer science and Engineering Nanjing University of Science and TechnologyNanjing 210094China School of Computer science and Engineering Southeast UniversityNanjing 211189China

The mobile crowdsensing software systems can complete large-scale and complex sensing tasks with the help of the collective intelligence from large numbers of ordinary users. In this paper, we build a typical crowdsensing system, which can efficiently calibrate large numbers of smartphone barometer sensors. The barometer sensor now becomes a very common sensor on smartphones. It is very useful in many applications, such as positioning, environment sensing and activity detection. Unfortunately, most smartphone barometers today are not accurate enough, and it is rather challenging to efficiently calibrate a large number of smartphone barometers. Here, we try to achieve this goal by designing a crowdsensingbased smartphone calibration system, which is called CBSC. It makes use of low-power barometers on smartphones and needs few reference points and little human assistant. We propose a hidden markov model for peer-to-peer calibration, and calibrate all the barometers by solving a minimum dominating set problem. The field studies show that CBSC can get an accuracy of within 0.1 hPa in 84% cases. Compared with the traditional solutions, CBSC is more practical and the accuracy is satisfying. The experience gained when building this system can also help the development of other crowdsensing-based systems.

关键词： crowdsensing system smartphone sensing barometer calibration

Optimal Output Tracking Control and Stabilization of Networked Control Systems with Packet Losses

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Journal of Systems science & Complexity 2021年第2期34卷 602-617页

作者： LIU Yue HAN Chunyan School of Electrical Engineering University of JinanJinan 250022China

This paper studies the optimal output tracking control and stabilization for networked control systems with packet losses via output feedback *** finite-horizon and infinite-horizon cases are *** the finite-horizon case,the authors introduce an augmented system according to the state variable and the reference trajectory for the first *** on a set of difference Riccati equations,an optimal output feedback tracking controller is proposed by applying the stochastic maximum *** an optimal estimator is *** the infinite-horizon case,a necessary and sufficient condition for the stabilization of the system is *** an optimal output feedback stabilizing tracking controller is obtained by establishing a set of algebraic Riccati ***,numerical examples are given to verify the proposed results.

关键词： Networked control system output feedback control packet losses stabilization tracking control

Algebraic Verification of Finite Group-Based Potential Games with Vector Payoffs

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Journal of Systems science & Complexity 2022年第6期35卷 2131-2144页

作者： WANG Yuanhua LI Haitao Business School Shandong Normal UniversityJi'nan 250014China School of mathematics and Statistics Shandong Normal UniversityJi'nan 250014China

This paper studies a class of strategic games,where players often collaborate with other players to form a group when making decisions,and the payoff functions of players in such games are presented as vector ***,using the semi-tensor product(STP)method,it is proved that a finite game with vector payoffs is potential if and only if its potential equation has *** adding a suitable weight vector to the vector payoffs of each player,a finite game with vector payoffs that is not potential can be converted into a potential ***,as a natural generalization,the authors consider the verification problem of the group-based potential games with vector *** solving a linear potential equation,a simple formula is obtained to calculate the corresponding potential ***,some examples are presented and discussed in detail to illustrate the theoretical results.

关键词： Group-based potential games potential equation semi-tensor product of matrices vector payoffs

Fast-armored target detection based on multi-scale representation and guided anchor

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Defence Technology（防务技术） 2020年第4期16卷 922-932页

作者： Fan-jie meng Xin-qing Wang Fa-ming Shao Dong Wang Xiao-dong Hu Department of mechanical Engineering College of Field EngineeringArmy Engineering University of PLANanjing210007China

Focused on the task of fast and accurate armored target detection in ground battlefield,a detection method based on multi-scale representation network(mS-RN) and shape-fixed Guided Anchor(SF-GA)scheme is ***,considering the large-scale variation and camouflage of armored target,a new mS-RN integrating contextual information in battlefield environment is *** mS-RN extracts deep features from templates with different scales and strengthens the detection ability of small *** targets of different sizes are detected on different representation ***,aiming at the accuracy and real-time detection requirements,improved shape-fixed Guided Anchor is used on feature maps of different scales to recommend regions of interests(ROIs).Different from sliding or random anchor,the SF-GA can filter out 80% of the regions while still improving the recall.A special detection dataset for armored target,named Armored Target Dataset(ARTD),is constructed,based on which the comparable experiments with state-of-art detection methods are *** results show that the proposed method achieves outstanding performance in detection accuracy and efficiency,especially when small armored targets are involved.

关键词： red image RPN Fast-armored target detection based on multi-scale representation and guided anchor

Settlement mechanism of piled-raft foundation due to cyclic train loads and its countermeasure

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Earthquake Engineering and Engineering Vibration 2017年第3期16卷 499-511页

作者： Gu Linlin Ye Guanlin Wang Zhen Ling Xianzhang Zhang Feng Department of Civil Engineering Qingdao University of Technology Department of Civil Engineering and State key Laboratory of Ocean Engineering Shanghai Jiaotong University Department of Geotechnical Engineering Tongji University Department of Civil Engineering Nagoya Institute of Technology

In this paper, numerical simulation with soil-water coupling finite element-finite difference（FE-FD） analysis is conducted to investigate the settlement and the excess pore water pressure（EPWP） of a piled-raft foundation due to cyclic high-speed（speed： 300km/h） train loading. To demonstrate the performance of this numerical simulation, the settlement and EPWP in the ground under the train loading within one month was calculated and confirmed by monitoring data, which shows that the change of the settlement and EPWP can be simulated well on the whole. In order to ensure the safety of train operation, countermeasure by the fracturing grouting is proposed. Two cases are analyzed, namely, grouting in No-4 softest layer and No-9 pile bearing layer respectively. It is found that fracturing grouting in the pile bearing layer（No-9 layer） has better effect on reducing the settlement.

关键词： high-speed train piled-raft foundation FEm settlement soil-pile interaction fracturing grouting.

Shape memory effect of dual-phase NimnGaTb ferromagnetic shape memory alloys

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Journal of Iron and Steel Research International 2019年第3期26卷 321-328页

作者： Jiang Zhang Yong-hong ma Ruo-lin Wu Jing-min Wang Institute of Higher Education Beihang UniversityBeijing 100191China School of materials science and Engineering Beihang UniversityBeijing 100191China Central Iron&Steel Research Institute Beijing 100081China

The evolution of microstructure,reverse martensitic transformation and the conelated influence on shape memory effect was investigated in as-cast and directionally solidified dual-phase NimnGaTb *** directionally solidified alloys exhibit single-crystal microstructure,preferred dendrite microstructure,and mussy dendrite microstructure in the specimens grown at a withdrawal rate(v)of 10,50 and 200,and 1000μm/s,*** precipitates dispersively distribute in the martensite matrix for the directionally solidified *** the refined grains and particle precipitates,the reverse martensitic transformation gradually shifts to lower temperatures and the temperature span is significantly *** directional solidification technology can effectively enhance the strains recovered due to shape memory effect C;sme)and decrease the compressive stress required to trigger the reorientation of twins(δ)via the realization of preferred orientation,while the maximalεsme and minimumδcan reach 4.96%and 14 mPa in v=10μm/s specimens,*** formation of dendrite morphology degrades the shape memory strain,andεsme decreases with the growth of secondary dendritic arms.

关键词： NimnGaTb alloy Directional solidification Dual-phase microstructure Shape memory effect

Scalable and Adaptive Joins for Tra jectory Data in Distributed Stream System

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Journal of Computer science & Technology 2019年第4期34卷 747-761页

作者： Jun-Hua Fang Peng-Peng Zhao An Liu Zhi-Xu Li Lei Zhao Institute of Artificial Intelligence School of Computer Science and TechnologySoochow UniversitySuzhou 215006ChinaNeusoft CorporationShenyang 110179China Institute of Artificial Intelligence School of Computer Science and TechnologySoochow UniversitySuzhou 215006China

As a fundamental operation in LBS(location-based services),the trajectory similarity of moving objects has been extensively studied in recent ***,due to the increasing volume of moving object trajectories and the demand of interactive query performance,the trajectory similarity queries are now required to be processed on massive datasets in a real-time *** work has proposed distributed or parallel solutions to enable large-scale trajectory similarity ***,those techniques cannot be directly adapted to the real-time scenario as it is likely to generate poor balancing performance when workload variance occurs on the incoming trajectory *** this paper,we propose a new workload partitioning framework,ART(Adaptive Framework for Real-Time Trajectory Similarity),which introduces practical algorithms to support dynamic workload assignment for RTTS(real-time trajectory similarity).Our proposal includes a processing model tailored for the RTTS scenario,a load balancing framework to maximize throughput,and an adaptive data partition manner designed to cut off unnecessary network *** on this,our model can handle the large-scale trajectory similarity in an on-line scenario,which achieves scalability,effectiveness,and efficiency by a single *** studies on synthetic data and real-world stream applications validate the usefulness of our proposal and prove the huge advantage of our approach over state-of-the-art solutions in the literature.

关键词： real-time data processing distributed computing trajectory similarity load balancing

A Coastal Zone Segmentation Variational model and Its Accelerated ADmm method

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Journal of Ocean University of china 2017年第6期16卷 1081-1089页

作者： HUANG Baoxiang CHEN Ge ZHANG Xiaolei YANG Huan College of Computer science and Technology Postdoctoral stations of system scienceQingdao University College of Information science and Engineering Ocean University of China

Effective and efficient SAR image segmentation has a significant role in coastal zone interpretation. In this paper, a coastal zone segmentation model is proposed based on Potts model. By introducing edge self-adaption parameter and modifying noisy data term, the proposed variational model provides a good solution for the coastal zone SAR image with common characteristics of inherent speckle noise and complicated geometrical details. However, the proposed model is difficult to solve due to to its nonlinear, non-convex and non-smooth characteristics. Followed by curve evolution theory and operator splitting method, the minimization problem is reformulated as a constrained minimization problem. A fast alternating minimization iterative scheme is designed to implement coastal zone segmentation. Finally, various two-stage and multiphase experimental results illustrate the advantage of the proposed segmentation model, and indicate the high computation efficiency of designed numerical approximation algorithm.

关键词： coastal zone segmentation variational Potts model alternating direction method with multipliers edge self-adaption

Cooperative interception with fast multiple model adaptive estimation

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Defence Technology（防务技术） 2021年第6期17卷 1905-1917页

作者： Shao-bo Wang Yang Guo Shi-cheng Wang Zhi-guo Liu Shuai Zhang Xi’an Research Institution of Hi-Technology China Xi’an Research Institution of Hi-Technology Northwestern Polytechnical UniversityChina

For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang-bang evasive maneuver with a random switching *** Fast multiple model adaptive estimation(Fast mmAE)algorithm,the cooperative guidance law takes detection configuration affecting the accuracy of interception into *** the detection error model related to the line-of-sight(LOS)separation angle of two interceptors,an optimal cooperative guidance law solving the optimization problem is designed to modulate the LOS separation angle to reduce the estimation error and improve the interception *** to the uncertainty of the target bang-bang maneuver switching time and the effective fitting of its multi-modal motion,Fast mmAE is introduced to identify its maneuver switching time and estimate the acceleration of the target to track and intercept the target *** designed cooperative optimal guidance law with Fast mmAE has better estimation ability and interception performance than the traditional guidance law and estimation method via monte Carlo simulation.

关键词： Cooperative guidance Optimal control Fast multiple model adaptive estimation (fast mmAE) Bang-bang maneuver Switch time Detection configuration Estimation error