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An Efficient Multilevel Threshold Image Segmentation Method for COVID-19 Imaging Using Q-Learning Based Golden Jackal Optimization

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Journal of Bionic Engineering 2023年第5期20卷 2276-2316页

作者： zihao wang Yuanbin Mo Mingyue Cui School of Artificial Intelligence Guangxi Minzu UniversityNanningChina Guangxi Key Laboratory of Hybrid Computation and IC Design Analysis Guangxi Minzu UniversityNanning530006China

From the end of 2019 until now,the Coronavirus Disease 2019(COVID-19)has been rampaging around the world,posing a great threat to people's lives and health,as well as a serious impact on economic *** the severely infectious nature of COVID-19,the diagnosis of COVID-19 has become *** through the use of Computed Tomography(CT)images is an efficient and quick ***,scientific researchers have proposed numerous segmentation methods to improve the diagnosis of CT *** this paper,we propose a reinforcement learning-based golden jackal optimization algorithm,which is named QLGJO,to segment CT images in furtherance of the diagnosis of *** learning is combined for the first time with meta-heuristics in segmentation *** strategy can effectively overcome the disadvantage that the original algorithm tends to fall into local *** addition,one hybrid model and three different mutation strategies were applied to the update part of the algorithm in order to enrich the diversity of the *** experiments were carried out to test the performance of the proposed ***,compare QLGJO with other advanced meta-heuristics using the IEEE CEC2022 benchmark ***,QLGJO was experimentally evaluated on CT images of COVID-19 using the Otsu method and compared with several well-known *** is shown that QLGJO is very competitive in benchmark function and image segmentation experiments compared with other advanced ***,the source code of the QLGJO is publicly available at https://***/Vang-z/QLGJO.

关键词： COVID-19 Bionic algorithm Golden jackal optimization Image segmentation Otsu and Kapur method

Multi-Robot Collaborative Hunting in Cluttered Environments With Obstacle-Avoiding Voronoi Cells

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1643-1655页

作者： Meng Zhou zihao wang Jing wang Zhengcai Cao the School of Electrical and Control Engineering North China University of TechnologyBeijing 100144China IEEE the College of Information Science and Technology Beijing University of Chemical TechnologyBeijing 100029China

This work proposes an online collaborative hunting strategy for multi-robot systems based on obstacle-avoiding Voronoi cells in a complex dynamic environment. This involves firstly designing the construction method using a support vector machine(SVM) based on the definition of buffered Voronoi cells(BVCs). Based on the safe collision-free region of the robots, the boundary weights between the robots and the obstacles are dynamically updated such that the robots are tangent to the buffered Voronoi safety areas without intersecting with the obstacles. Then, the robots are controlled to move within their own buffered Voronoi safety area to achieve collision-avoidance with other robots and obstacles. The next step involves proposing a hunting method that optimizes collaboration between the pursuers and evaders. Some hunting points are generated and distributed evenly around a circle. Next, the pursuers are assigned to match the optimal points based on the Hungarian ***, a hunting controller is designed to improve the containment capability and minimize containment time based on collision risk. Finally, simulation results have demonstrated that the proposed cooperative hunting method is more competitive in terms of time and travel distance.

关键词： Dynamic obstacle avoidance multi-robot collaborative hunting obstacle-avoiding Voronoi cells task allocation

Third-order polynomial model for analyzing stickup state laminated structure in flexible electronics

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Acta Mechanica Sinica 2018年第1期34卷 48-61页

作者： Xianhong Meng zihao wang Boya Liu Shuodao wang School of Aeronautic Science and Engineering Beihang University Beijing 100191 China School of Mechanical and Aerospace Engineering Oklahoma State University Stillwater OK 74078 USA

Laminated hard-soft integrated structures play a significant role in the fabrication and development of flexible electronics devices. Flexible electronics have advantageous characteristics such as soft and light-weight, can be folded,twisted, flipped inside-out, or be pasted onto other surfaces of arbitrary shapes. In this paper, an analytical model is presented to study the mechanics of laminated hard-soft structures in flexible electronics under a stickup state. Thirdorder polynomials are used to describe the displacement field,and the principle of virtual work is adopted to derive the governing equations and boundary conditions. The normal strain and the shear stress along the thickness direction in the bimaterial region are obtained analytically, which agree well with the results from finite element analysis. The analytical model can be used to analyze stickup state laminated structures, and can serve as a valuable reference for the failure prediction and optimal design of flexible electronics in the future.

关键词： Flexible electronics Stickup state Third-order polynomials Virtual work principle

Analytical study of wrinkling in thin-film-on-elastomer system with finite substrate thickness

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Applied Mathematics and Mechanics(English Edition) 2017年第4期38卷 469-478页

作者： Xianhong MENG Guanyu LIU zihao wang Shuodao wang School of Aeronautic Science and Engineering Beihang University School of Mechanical and Aerospace Engineering Oklahoma State University

Surface wrinkling, a film bonded on a pre-strained elastomeric substrate can form periodic wrinkling patterns, is a common phenomenon in daily life. In existing theoretical models, the film is much thinner than the substrate so that the substrate can be considered to be elastomeric with infinite thickness. In this paper, the effect of finite substrate thickness is analyzed theoretically for free boundary condition cases. Based on the minimum potential energy principle, a theoretical model is established, and the wave length and amplitude of the wrinkling pattern are obtained. When the thickness of the substrate is more than 200 times larger than the thickness of the film, the results of this study agree well with the results obtained from the previous models for infinite substrate thickness. However, for thin substrates, the effect of finite substrate thickness becomes significant. The model given in this paper accurately describes the effect of finite substrate thickness, providing important design guidelines for future thin-film-on-substrate systems such as stretchable electronic devices.

关键词： wrinkling finite substrate thickness theoretical mechanics model

Exact distributions for stochastic models of gene expression with arbitrary regulation

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Science China Mathematics 2020年第3期63卷 485-500页

作者： zihao wang Zhenquan Zhang Tianshou Zhou School of Mathematics Sun Yat-sen University

Stochasticity in gene expression can result in fluctuations in gene product levels. Recent experiments indicated that feedback regulation plays an important role in controlling the noise in gene expression.A quantitative understanding of the feedback effect on gene expression requires analysis of the corresponding stochastic model. However, for stochastic models of gene expression with general regulation functions, exact analytical results for gene product distributions have not been given so far. Here, we propose a technique to solve a generalized ON-OFF model of stochastic gene expression with arbitrary(positive or negative, linear or nonlinear) feedbacks including posttranscriptional or posttranslational regulation. The obtained results, which generalize results obtained previously, provide new insights into the role of feedback in regulating gene expression. The proposed analytical framework can easily be extended to analysis of more complex models of stochastic gene expression.

关键词： gene expression ON-OFF model feedback regulation chemical master equation stationary distribution

3D shape retrieval based on Laplace operator and joint Bayesian model

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Visual Informatics 2020年第3期4卷 69-76页

作者： wang zihao Lin Hongwei School of Mathematics Zhejiang UniversityHangzhou 310027China State Key Laboratory of CAD&CG Zhejiang UniversityHangzhou 310058China

Feature analysis plays a significant role in computer vision and computer *** the task of shape retrieval,shape descriptor is *** recent years,feature extraction based on deep learning becomes very popular,but the design of geometric shape descriptor is still meaningful due to the contained intrinsic information and *** paper proposes an effective and robust descriptor of 3D *** descriptor is constructed based on the probability distribution of the normalized eigenfunctions of the Laplace–Beltrami operator on the surface,and a spectrum method for dimensionality *** distance metric of the descriptor space is learned by utilizing the joint Bayesian model,and we introduce a matrix regularization in the training stage to re-estimate the covariance ***,we apply the descriptor to 3D shape retrieval on a public *** show that our method is robust and has good retrieval performance.

关键词： Laplace-Beltrami operator Joint Bayesian Shape retrieval

A multi agent-based optimal control method for combined cooling and power systems with thermal energy storage

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Building Simulation 2021年第6期14卷 1709-1723页

作者： zihao wang Chaobo Zhang Hongbo Li Yang Zhao State Key Laboratory of Air-Conditioning Equipment and System Energy Conservation ZhuhaiChina Guangdong Key Laboratory of Refrigeration Equipment and Energy Conservation Technology ZhuhaiChina Institute of Refrigeration and Cryogenics Zhejiang UniversityHangzhouChina

Combined cooling,heating and power(CCHP)systems have been considered as a potential energy saving technology for buildings due to their high energy efficiency and low carbon *** energy storage(TES)can improve the energy efficiency of CCHP systems,since they reduce the mismatch between the energy supply and ***,it also increases the complexity of operation optimization of CCHP *** this study,a multi-agent system(MAS)-based optimal control method is proposed to minimize the operation cost of CCHP systems combined with *** types of agents,i.e.,coordinator agents,building agents,energy management agents and optimization agents,are implemented in the MAS to cooperate with each *** operation optimization problem is solved by the genetic algorithm.A simulated system is utilized to validate the performance of the proposed *** show that the operation cost reductions of 10.0%on a typical summer day and 7.7%on a typical spring day are achieved compared with a rule-based control method.A sensitivity analysis is further performed and results show that the optimal operation cost does not change obviously when the rated capacity of TES exceeds a threshold.

关键词： multi-agent systems distributed control-operation optimization demand response combined cooling,heating and power system thermal energy storage

Modeling and Analyzing for a Novel Continuum Model Considering Self-Stabilizing Control on Curved Road with Slope

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Computer Modeling in Engineering & Sciences 2022年第6期131卷 1815-1830页

作者： Li Lei zihao wang Yong Wu School of Energy and Power Engineering Shandong UniversityJinan250061China School of Control Science and Engineering Shandong UniversityJinan250061China Department of Logistics Management Ningbo University of Finance and EconomicsNingbo315175China

It is essential to fully understand master the traffic characteristics of the self-stabilizing control effect and roadcharacteristics to ensure the regular operation of transportation. Traffic flow on curved roads and slopes is irregularand more complicated than that on the straight road. However, most of the research only considers the effect ofself-stabilizing in the straight road. This study attempts to bridge this deficiency from the following three ***, we review the potential influencing factors of traffic flow stability, which are related to the vehicle’s steadyvelocity, history velocity, and the turn radius of the road and the slope of the road. Based on the above review,an extended continuum model accounting for the self-stabilizing effect on a curved road with slope is ***, the linear stability criterion of the new model is derived by applying linear stability theory, and the neutralstability curve is obtained in detail. The modified KdV equation describing the evolution characteristics of trafficcongestion is derived by using the nonlinear analysis method. Upon the theoretical analysis, the third aspectfocuses on simulating the self-stabilizing effect under different slopes and radius, which demonstrates that theself-stabilizing effect is conducive to reducing congestion of the curved road with slope.

关键词： Traffic flow KdV equation self-stabilizing effect gradient highway curved road

A Path Planning Algorithm Based on Improved RRT Sampling Region

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Computers, Materials & Continua 2024年第9期80卷 4303-4323页

作者： Xiangkui Jiang zihao wang Chao Dong College of Automation Xi’an University of Posts and TelecommunicationsXi’an710121China

For the problem of slow search and tortuous paths in the Rapidly Exploring Random Tree(RRT)algorithm,a feedback-biased sampling RRT,called FS-RRT,is proposedbasedon ***,toimprove the samplingefficiency of RRT to shorten the search time,the search area of the randomtree is restricted to improve the sampling ***,to obtain better information about obstacles to shorten the path length,a feedback-biased sampling strategy is used instead of the traditional random sampling,the collision of the expanding node with an obstacle generates feedback information so that the next expanding node avoids expanding within a specific angle ***,this paper proposes using the inverse optimization strategy to remove redundancy points from the initial path,making the path shorter and more ***,to satisfy the smooth operation of the robot in practice,auxiliary points are used to optimize the cubic Bezier curve to avoid path-crossing obstacles when using the Bezier curve *** experimental results demonstrate that,compared to the traditional RRT algorithm,the proposed FS-RRT algorithm performs favorably against mainstream algorithms regarding running time,number of search iterations,and path ***,the improved algorithm also performs well in a narrow obstacle environment,and its effectiveness is further confirmed by experimental verification.

关键词： RRT inversive optimization path planning feedback bias sampling mobile robots