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CVTD: A Robust Car-Mounted Video Text Detector

Computers, Materials & Continua 2024年第2期78卷 1821-1842页

作者： di zhou Jianxun Zhang Chao Li Yifan Guo Bowen Li Department of Computer Science and Engineering Chongqing University of TechnologyChongqingChina College of Information and Engineering Jingdezhen Ceramic UniversityJingdezhenChina

Text perception is crucial for understanding the semantics of outdoor scenes,making it a key requirement for building intelligent systems for driver assistance or autonomous driving.Text information in car-mounted videos can assist drivers in making decisions.However,Car-mounted video text images pose challenges such as complex backgrounds,small fonts,and the need for real-time detection.We proposed a robust Car-mounted Video Text Detector(CVTD).It is a lightweight text detection model based on ResNet18 for feature extraction,capable of detecting text in arbitrary shapes.Our model efficiently extracted global text positions through the Coordinate Attention Threshold Activation(CATA)and enhanced the representation capability through stacking two Feature Pyramid Enhancement Fusion Modules(FPEFM),strengthening feature representation,and integrating text local features and global position information,reinforcing the representation capability of the CVTD model.The enhanced feature maps,when acted upon by Text Activation Maps(TAM),effectively distinguished text foreground from non-text regions.Additionally,we collected and annotated a dataset containing 2200 images of Car-mounted Video Text(CVT)under various road conditions for training and evaluating our model’s performance.We further tested our model on four other challenging public natural scene text detection benchmark datasets,demonstrating its strong generalization ability and real-time detection speed.This model holds potential for practical applications in real-world scenarios.

关键词： Deep learning text detection Car-mounted video text detector intelligent driving assistance arbitrary shape text detector

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Tiered clustering-based management architecture in mega-satellite networks

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Science China(Information Sciences) 2024年第5期67卷 215-227页

作者： Qi HAO di zhou Min SHENG Yan SHI Jiandong LI State Key Laboratory of Integrated Service Networks Xidian University

Hybrid orbital networking and the proliferation of satellites raise explosive management complexity in mega-satellite networks(MSNs) and prompt the management architecture to the hierarchy. In this regard, we propose a tiered clustering-based management architecture(TCMA) to realize the high-efficient and low-cost management performance. Specifically, based on the constrained satellite coverage, we derive an expression of the mapping relationship between the required control overhead of the controller interaction,the average path length of the proposed TCMA, and the corresponding number of management tiers and cluster size. The expression can determine the optimal number of tiers of the TCMA by minimizing the required flow table size between controllers, while ensuring high transmission efficiency. We then exhibit the elasticity of the hierarchical TCMA by adding the peer connections at the second-highest management tier to reduce maximum redundant paths. Simulation results verify the effectiveness of the proposed TCMA and illustrate that a 3-tier TCMA is sufficient for thousands of satellites.

关键词： mega-satellite networks hierarchical architecture average hop tiered structure clustering

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Time-Domain Analysis of Body Freedom Flutter Based on 6DOF Equation

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工程与科学中的计算机建模(英文) 2024年第1期138卷 489-508页

作者： Zhehan Ji Tongqing Guo di zhou Zhiliang Lu Binbin Lyu Key Laboratory of Unsteady Aerodynamics and Flow Control Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing210016China High Speed Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang621000China

The reduced weight and improved efficiency of modern aeronautical structures result in a decreasing separation of frequency ranges of rigid and elastic modes.Particularly,a high-aspect-ratio flexible flying wing is prone to body freedomflutter(BFF),which is a result of coupling of the rigid body short-periodmodewith 1st wing bendingmode.Accurate prediction of the BFF characteristics is helpful to reflect the attitude changes of the vehicle intuitively and design the active flutter suppression control law.Instead of using the rigid body mode,this work simulates the rigid bodymotion of the model by using the six-degree-of-freedom(6DOF)equation.A dynamicmesh generation strategy particularly suitable for BFF simulation of free flying aircraft is developed.An accurate Computational Fluid Dynamics/Computational Structural Dynamics/six-degree-of-freedom equation(CFD/CSD/6DOF)-based BFF prediction method is proposed.Firstly,the time-domain CFD/CSD method is used to calculate the static equilibrium state of the model.Based on this state,the CFD/CSD/6DOF equation is solved in time domain to evaluate the structural response of themodel.Then combinedwith the variable stiffnessmethod,the critical flutter point of the model is obtained.This method is applied to the BFF calculation of a flyingwing model.The calculation results of the BFF characteristics of the model agree well with those fromthe modalmethod andNastran software.Finally,the method is used to analyze the influence factors of BFF.The analysis results show that the flutter speed can be improved by either releasing plunge constraint or moving the center ofmass forward or increasing the pitch inertia.

关键词： Body freedom flutter time-domain CFD/CSD/6DOF method dynamic mesh generation strategy aeroelasticity

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An Optimization Method for Seismic Reliability of Regional Road Networks

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Journal of Traffic and Transportation Engineering(English Edition) 2024年

作者： Fei Wang Minqing Zhu Hongjun Cui Qihang zhou Xinyu Sun di zhou Xinwei Ma School of Architecture and Art Design Hebei University of Technology School of Civil and Transportation Engineering Hebei University of Technology Tianjin Sino-German University of Applied Sciences Hebei Expressway Group Limited Shi Huang Branch

To enhance the efficacy of seismic reliability assessments within regional road networks， this study introduces the constructs of Forbidden Edge Sets and Iterable Edge Sets within the framework of the Quick Fixed-node Unconnected Subgraph Algorithm (QFUS). Through optimization of the subgraph iteration process， the Quick Subgraph Algorithm (QSA) has been developed， exhibiting a diminished temporal complexity. Examining the topological architecture of road network systems， this research proposes the notion of road unit criticality. The corresponding equations have been formulated and empirically validated. Addressing the seismic optimization challenge of road networks， an optimization model has been constructed， and the Additive Edge Method has been introduced， aiming to minimize the requisite investment for enhancements. The algorithms QSA and the Additive Edge Method were applied to the road network in the vicinity of Zhangjiakou for empirical analysis. The results indicate that the QSA algorithm enhances the computational efficiency of network reliability by 33.04% in comparison to the QFUS algorithm. The metric of road unit criticality effectively quantifies the influence of various road unit reinforcement strategies on the seismic reliability enhancement of road network systems. The Additive Edge Method proposed herein is shown to minimize the analytical scope required for road units within the network and achieves cost minimization for seismic optimization of the road network. The scientific validity and logical soundness of the Additive Edge Method have been corroborated through the application of the control variable technique.

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Long-term complete response to anti-programmed-death-1 monotherapy in a patient with relapsed and refractory ovarian adenocarcinoma: A case report

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World Journal of Clinical Cases 2024年第11期12卷 1967-1973页

作者： Guang-di zhou Qin Li Affiliated to Shanghai Jiao Tong University School of Medicine Xinhua HospitalShanghai 200092China Department of Obstetrics and Gynecology Shanghai Changhai HospitalShanghai 200433China

BACKGROUND Ovarian cancer is the most common malignant tumor of the female reproductive system,and the survival rate of patients with relapsed and refractory ovarian cancer is very low.CASE SUMMARY Here,we report a case of high-grade serous papillary adenocarcinoma of the ovary that was successfully treated with immunotherapy.Radical surgery and adjuvant chemotherapy for the 56-year-old patient were successful;however,her tumor relapsed.Subsequent second-line chemotherapy,targeted agents,and other treatments were ineffective,as the tumor continued to recur and metastasize.Anti-programmed cell death-1(PD-1)monotherapy(tislelizumab)completely alleviated the tumor,and the multiple metastatic tumors disappeared.To date,the patient has used anti-PD-1 for 32 months,experiencing no disease progression and maintaining good health without additional treatment.CONCLUSION This case suggests that anti-PD-1 immunotherapy may have long-term positive effects on outcomes in some refractory recurrent solid tumors.Further research is needed to identify patients most likely to respond to anti-PD-1 therapy.

关键词： Anti-programmed cell death-1 Tislelizumab Ovarian cancer Relapsed cancer treatment Immunotherapy Case report

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Time-varying parameters estimation with adaptive neural network EKF for missile-dual control system

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Journal of Systems Engineering and Electronics 2024年第2期35卷 451-462页

作者： YUAN Yuqi zhou di LI Junlong LOU Chaofei School of Astronautics Harbin Institute of TechnologyHarbin 150001China Beijing Institute of Electronic System Engineering Beijing 100854China

In this paper, a filtering method is presented to estimate time-varying parameters of a missile dual control system with tail fins and reaction jets as control variables. In this method, the long-short-term memory(LSTM) neural network is nested into the extended Kalman filter(EKF) to modify the Kalman gain such that the filtering performance is improved in the presence of large model uncertainties. To avoid the unstable network output caused by the abrupt changes of system states,an adaptive correction factor is introduced to correct the network output online. In the process of training the network, a multi-gradient descent learning mode is proposed to better fit the internal state of the system, and a rolling training is used to implement an online prediction logic. Based on the Lyapunov second method, we discuss the stability of the system, the result shows that when the training error of neural network is sufficiently small, the system is asymptotically stable. With its application to the estimation of time-varying parameters of a missile dual control system, the LSTM-EKF shows better filtering performance than the EKF and adaptive EKF(AEKF) when there exist large uncertainties in the system model.

关键词： long-short-term memory(LSTM)neural network extended Kalman filter(EKF) rolling training time-varying parameters estimation missile dual control system

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Effect of the Particle Packing Configuration on Fixed Bed Performance

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 152-160页

作者： Li Ziqi Bao di zhou Han Tang Xiaojin SINOPEC Research Institute of Petroleum Processing Co. Ltd.Beijing 100083China

Fixed-bed reactors are generally considered the optimal choice for numerous multi-phase catalytic reactions due to their excellent performance and stability.However,conventional fixed beds often encounter challenges related to inadequate mass transfer and a high pressure drop caused by the non-uniform void fraction distribution.To enhance the overall performance of fixed beds,the impact of different packing configurations on performance was investigated.Experimental and simulation methods were used to investigate the fluid flow and mass transfer performances of various packed beds under different flow rates.It was found that structured beds exhibited a significantly lower pressure drop per unit length than conventional packed beds.Furthermore,the packing configurations had a critical role in improving the overall performance of fixed beds.Specifically,structured packed beds,particularly the H-2 packing configuration,effectively reduced the pressure drop per unit length and improved the mass transfer efficiency.The H-2 packing configuration consisted of two parallel strips of particles in each layer,with strips arranged perpendicularly between adjacent layers,and the spacing between the strips varied from layer to layer.

关键词： packing configurations fixed bed Computational Fluid Dynamics simulation pressure drop mass transfer

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Optimal predictive sliding-mode guidance law for intercepting near-space hypersonic maneuvering target

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Chinese Journal of Aeronautics 2022年第4期35卷 320-331页

作者： Bolun ZHANG di zhou School of Astronautics Harbin Institute of TechnologyHarbin 150001China

The design of optimal guidance law for intercepting a near-space hypersonic maneuvering target with bounded inputs is considered. Firstly, a maneuvering model for near-space hypersonic aircraft is given. Then, the aircraft acceleration prediction can be obtained using this model with two neural networks. By using the target acceleration prediction, which is taken into account when calculating the Zero Effort Miss(ZEM), an optimal sliding-mode guidance law is proposed to fulfill the guidance task. An adaptive sliding-mode switch term is designed to deal with actuator saturation and prediction errors. Finally, numerical simulations show that the proposed guidance law can reduce the energy consumption and the terminal acceleration command of the interceptor effectively.

关键词： Adaptive sliding-mode control Near-space hypersonic aircraft Neural networks Optimal control Predictive guidance law

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Autophagy and circadian rhythms:interactions and clinical implications

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BIOCELL 2024年第1期48卷 33-45页

作者： TIANKAI di ZHIFEI zhou FEN LIU YUJIANG CHEN LULU WANG State Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration National Clinical Research Center for Oral DiseasesShaanxi Clinical Research Center for Oral DiseasesDepartment of Pediatric DentistrySchool of StomatologyThe Fourth Military Medical UniversityXi’an710032China Department of Stomatology The 969th HospitalJoint Logistics Support Force of the Chinese People’s Liberation ArmyHohhot010000China Department of Stomatology General Hospital of Tibetan Military CommandLhasa850000China Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research Clinical Research Center of Shaanxi Province for Dental and Maxillofacial DiseasesDepartment of Pediatric DentistryCollege of StomatologyXi’an Jiaotong UniversityXi’an710000China Department of Neurobiology and Institute of Neurosciences School of Basic MedicineFourth Military Medical UniversityXi’an710032China

Autophagy is a widespread biological process that controls cellular growth,survival,development,and death.Circadian rhythm is a recurring reaction of living organisms and behaviors to variations in surrounding brightness and obscurity.Most of the fundamental physiological processes in mammals,such as the sleep-wake pattern and the rhythm of nutrition and energy metabolism,are governed by circadian rhythms.Research has indicated that autophagy exhibits a specific circadian pattern in both normal and abnormal conditions.Autophagy can modulate circadian rhythms by breaking down proteins that regulate the circadian clock.The potential regulatory connection between the two has been a popular subject of clinical and fundamental research.Understanding the interaction between circadian rhythm and autophagy could potentially lead to the development of novel approaches for disease treatment in the future.The present analysis presented a summary of the molecular processes implicated in the interplay between autophagy and circadian rhythm,as well as the pathological importance of the disrupted regulatory association between these two phenomena.

关键词： Autophagy Circadian rhythms Mechanism Application

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Polymorphic cerium-based Prussian blue derivatives with in situ growing CNT/Co heterojunctions for enhanced microwave absorption via polarization and magnetization

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Nano Research 2024年第3期17卷 2050-2060页

作者： Jixi zhou Xinmeng Huang di Lan Yuhang Cheng Fengyi Xue Chenyu Jia Guanglei Wu Zirui Jia Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China School of Materials Science and Engineering Hubei University of Automotive TechnologyShiyan 442002China College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071China

In this paper,the structure evolution of cerium cobaltohexanoate(Ce[Co(CN)6],Ce-Co Prussian blue analog(PBA))has been realized by solvent catalysis at room temperature.The hexagonal bipyramidal microcrystals of Ce-Co PBA can be gradually transformed into dendrites by different proportions of ethanol(EtOH)and water.At the same time,the porous dendrites CeO_(2)/Co@carbon nanotub(CNT)with oxygen-rich vacancies(OVs)can be obtained by annealing Ce-Co PBA at 700℃.The microstructure study shows that carbon nanotubes will be catalyzed after annealing at high temperature,and the cobalt metal particles encapsulated in carbon nanotubes will be anchored in the matrix,regulating the impedance matching and multi-polarization suppression of the material,and its unique structure,vacancies,and strong interface effect make the material exhibit excellent electromagnetic wave(EMW)absorption performance.When the matching thickness is 2.5 mm,the minimum reflection loss(RLmin)of the composite is-51.68 dB,and the effective absorption bandwidth(RLdidate material for EMW absorption.

关键词： Ce-Co Prussian blue analog(PBA) carbon nanotubes(CNTs) CeO_(2)/Co@CNT solvent catalysis electromagnetic wave absorption

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