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计算机工程与应用 2025年第1期61卷 153-164页

作者：白锋马庆禄赵敏重庆交通大学土木工程学院重庆400074 重庆交通大学交通运输学院重庆400074 重庆大学自动化学院重庆400044

针对当前道路巡检智能化程度不足以及效率低等现状,为提高利用无人机道路巡检检测效率与检测精度,在YOLOv8s的基础上针对无人机航拍场景提出改进模型AC-YOLO,在主干网络引入动态大卷积核注意机制LSK-attention来扩展模型的感受野,提高... 详细信息

针对当前道路巡检智能化程度不足以及效率低等现状,为提高利用无人机道路巡检检测效率与检测精度,在YOLOv8s的基础上针对无人机航拍场景提出改进模型AC-YOLO,在主干网络引入动态大卷积核注意机制LSK-attention来扩展模型的感受野,提高对路面裂缝范围检测的准确性。在颈部结构设计多尺度特征融合策略,融入BiFPN网络,改善对细小裂缝的检测。替换损失函数为WIoUv3,优化梯度分配策略,使模型更加关注裂缝主体。在数据集UAV-PDD2023上进行实验验证,改进后AC-YOLO精准度达到0.895,较原模型提高0.128,mAP50达到0.791,提高0.071,F1得分提高0.051,模型大小减小8.5%,FPS达到了129,提高4%。同时采用不同任务验证了模型泛化性能,实验结果证明AC-YOLO具有更强的检测性能,能有效应用于无人机视角下的路面裂缝检测。

关键词：道路巡检裂缝检测航拍裂缝增强感知特征融合

Integrating lipidomics and gut microbiota to study the anti-hyperlipidemia effect of Sargentodoxae Caulis extract

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Traditional Medicine Research 2025年第1期10卷 1-11页

作者： Xiao-Xiao Zhang Li Jia Xiu-Jun Zhan Charity Ngina Qing-Rui Zhang Xiao-Ge Li Qi-Bao Jiang Shi bai Miao-Miao Jiang National Key Laboratory of Chinese Medicine Modernization Tianjin University of Traditional Chinese MedicineTianjin 301617China Haihe Laboratory of Modern Chinese Medicine Tianjin 301617China School of Medicine Taizhou UniversityTaizhou 318000China.

Background:Sargentodoxae Caulis(SC)is the vine stem of Sargentodoxa Cuneata(Oliv.)Rehd.&*** in ***,and it in traditional Chinese medicine has been known for promoting blood circulation and removing blood stasis as recorded in the ancient book“Illustrated Classics of Materia Medica”.It has been used effectively to treat blood stasis too in modern clinical ***,the anti-hyperlipidemia effect of SC is not fully *** paper aims at exploring the use of SC stems to improve the balance of blood lipids in the body,and its new role in treating ***:The effects of SC extract on hyperlipidemia were explored by combining lipidomics and gut ***,we explored the potential mechanism of SC in treating hyperlipidemia by pathway ***:The results showed that the stem extract of SC could restore the physiological and biochemical indices of hyperlipidemia in mice,as well as repair the morphological and structural damage to *** to the Model group,the SC extract significantly reduced the liver index,epididymal fat index,and Lee’s *** also significantly decreased serum levels of total cholesterol,triglycerides,low-density lipoprotein cholesterol,peroxisome proliferator-activated receptor gamma(PPAR-γ),D-lactate,and free fatty acids,while significantly increasing the relative content of peroxisome proliferator-activated receptor alpha(PPAR-α).These changes were statistically ***-targeted lipidomics,based on LC-MS,were utilized to investigate the lipid metabolism characteristics in serum,liver,and epididymal fat of the *** was observed that,compared to the blank group,the Model group exhibited significant changes primarily in glycerol lipids and *** treatment group also displayed alterations in these lipids.A total of 38,81,and 27 differential lipids were identified in serum,liver,and epididymal fat samples,*** these,14 common differenti

关键词： hyperlipidemia Sargentodoxae Caulis lipidomics intestinal flora

Application of Improved Hybrid Interface Substructural Component Modal Synthesis Method in Vibration Characteristics of Mistuned Blisk

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Chinese Journal of Mechanical Engineering 2014年第6期27卷 1219-1231页

作者： bai Bin bai Guangchen LI Chao School of Energy and Power Engineering Beihang University

The large and complex structures are divided into hundreds of thousands or millions degrees of freedom（DOF） when they are calculated which will spend a lot of time and the efficiency will be extremely low. The classical component modal synthesis method （CMSM） are used extensively, but for many structures in the engineering of high-rise buildings, aerospace systemic engineerings, marine oil platforms etc, a large amount of calculation is still needed. An improved hybrid interface substructural component modal synthesis method（HISCMSM） is proposed. The parametric model of the mistuned blisk is built by the improved HISCMSM. The double coordinating conditions of the displacement and the force are introduced to ensure the computational accuracy. Compared with the overall structure finite element model method（FEMM）, the computational time is shortened by23.86%–31.56%and the modal deviation is 0.002%–0.157% which meets the requirement of the computational accuracy. It is faster 4.46%–10.57% than the classical HISCMSM. So the improved HISCMSM is better than the classical HISCMSM and the overall structure FEMM. Meanwhile, the frequency and the modal shape are researched, considering the factors including rotational speed, gas temperature and geometry size. The strong localization phenomenon of the modal shape’s the maximum displacement and the maximum stress is observed in the second frequency band and it is the most sensitive in the frequency veering. But the localization phenomenon is relatively weak in 1st and the 3d frequency band. The localization of the modal shape is more serious under the condition of the geometric dimensioning mistuned. An improved HISCMSM is proposed, the computational efficiency of the mistuned blisk can be increased observably by this method.

关键词： modal shape mistuned blisk vibration characteristics computational efficiency computational accuracy

Adaptive Sliding-Mode Control of an Automotive Electronic Throttle in the Presence of Input Saturation Constraint

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IEEE/CAA Journal of Automatica Sinica 2018年第4期5卷 878-884页

作者： Rui bai School of Electrical Engineering Liaoning University of TechnologyJinzhou 121001China

In modern vehicles, electronic throttle(ET) has been widely utilized to control the airflow into gasoline engine. To solve the control difficulties with an ET, such as strong nonlinearity,unknown model parameters and input saturation constraints,an adaptive sliding-mode tracking control strategy for an ET is presented. Compared with the existing control strategies for an ET, input saturation constraints and parameter uncertainties are adequately considered in the proposed control strategy. At first, the nonlinear dynamic model for control of an ET is described. According to the dynamical model, the nonlinear adaptive sliding-mode tracking control method is presented,where parameter adaptive laws and auxiliary design system are employed. Parameter adaptive law is given to estimate the unknown parameter with an ET. An auxiliary system is designed,and its state is utilized in the tracking control method to handle the input saturation. Stability proof and analysis of the adaptive sliding-mode control method is performed by using Lyapunov stability theory. Finally, the reliability and feasibility of the proposed control strategy are evaluated by computer *** research shows that the proposed sliding-mode control strategy can provide good control performance for an ET.

关键词： Auxiliary design system electronic throttle(ET) input saturation parameter adaptive law sliding-mode control tracking control

Response of saturated porous media subjected to local thermal loading on the surface of semi-infinite space

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Acta Mechanica Sinica 2006年第1期22卷 54-61页

作者： Bing bai School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044 China

Heat source function method is adopted in the present paper to derive elementary solutions of coupled thermo-hydro-mechanical consolidation for saturated porous media under conjunct actions of instantaneous point heat source, instantaneous point fluid source and constant volume force. By using the so-called fictitious heat source method and images method, the solutions of a semi-infinite saturated porous medium subjected to a local heat source with time-varied intensity on its free surface are developed from elementary solutions. The numerical integral methods for calculating the unsteady temperature, pore pressure and displacement fields are given. The thermomechanical response are analyzed for the case of a circular planar heat source. Besides, the thermal consolidation characteristics of a saturated porous medium subjected to a harmonic thermal loading are also given, and the fluctuation processes of the field variables located below the center of heat source are analyzed.

关键词： Saturated porous media Thermal consolidation Elementary solution Heat source Method of images

Numerical simulation of turbulent flow around a forced moving circular cylinder on cut cells

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Journal of Hydrodynamics 2013年第6期25卷 829-838页

作者： bai Wei Department of Civil and Environmental Engineering National University of Singapore

Fixed and forced moving circular cylinders in turbulent flows are studied by using the Large Eddy Simulation （LES） and two-equation based Detached Eddy Simulation （DES） turbulence models. The Cartesian cut cell approach is adopted to track the body surface across a stationary background grid covering the whole computational domain. A cell-centered finite volume method of second-order accuracy in both time and space is developed to solve the flow field in fluid cells, which is also modified accordingly in cut cells and merged cells. In order to compare different turbulence models, the current flow past a fixed circular cylinder at a moderate Reynolds number, Re = 3 900, is tested first. The model is also applied to the simulation of a forced oscillating circular cylinder in the turbulent flow, and the influences of different oscillation amplitudes, frequencies and free stream velocities are discussed. The numerical results indicate that the present numerical model based on the Cartesian cut cell approach is capable of solving the turbulent flow around a body undergoing motions, which is a foundation for the possible future study on wake induced oscillation and vortex induced vibration.

关键词： Cartesian cut cell turbulent flow Large Eddy Simulation (LES) Detached Eddy Simulation (DES) forced oscillatingcylinder

基于耦合特征和改进随机森林的非侵入式农业负荷辨识

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供用电 2025年第1期42卷 106-115页

作者：刘俊雨白牧可张立梅河北农业大学信息科学与技术学院河北保定071000 中国电力科学研究院有限公司北京100192

随着高比例新能源和多元负荷的不断接入,配电网呈现出动态变化和交直流混合运行的特性,农业负荷类型的增加和负荷辨识问题对配电网智慧农业的实施提出了新挑战。提出了一种结合耦合特征和改进随机森林算法的非侵入式农业负荷辨识方法。... 详细信息

随着高比例新能源和多元负荷的不断接入,配电网呈现出动态变化和交直流混合运行的特性,农业负荷类型的增加和负荷辨识问题对配电网智慧农业的实施提出了新挑战。提出了一种结合耦合特征和改进随机森林算法的非侵入式农业负荷辨识方法。针对智慧农业当中负荷类型的多样性,分析了卷帘机、抽水泵、水平循环风扇等典型农业负荷的暂态特征与稳态特征,并结合农村分布式光伏发电数据,通过形态相似性分析提取了具有时间序列相关性的农业负荷耦合特征。基于历史负荷数据和特征,构造了样本矩阵作为随机森林算法的输入,并通过改进Bootstrap抽样、引入最优特征子集构造分类回归树(classification and regression tree,CART)决策树,以及基于负荷种类进行重复投票机制,构建了改进随机森林算法的农业负荷辨识架构。建立了准确率评价指标,通过仿真分析验证所提方法的有效性,并分析了关键参数对算法性能的影响。仿真结果表明,所提方法的准确率达到了98.96%,在辨识效率上相较其他算法有明显提升。

关键词：非侵入式农业负荷耦合特征形态相似随机森林

Simulation on the dynamic stability derivatives of battle-structure-damaged aircrafts

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Defence Technology（防务技术） 2021年第3期17卷 987-1001页

作者： bai-gang Mi School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China

Accurately evaluating the aerodynamic performance of a battle-structure-damaged aircraft is essential to enable the pilot to optimize the flight control strategy. Based on CFD and rigid dynamic mesh techniques,a numerical method is developed to calculate the longitudinal and longitudinal-lateral coupling forces and moments with small amplitude sinusoidal pitch oscillation, and the corresponding dynamic derivatives of two fragment-structure-damaged and two continuous-rod-damaged models modified from the SACCON UAV. The results indicate that, at the reference point set in this paper, additional positive damping is generated in fragment-damaged configurations;thus, the absolute values of the negative pitch dynamic derivative increase. The missing wingtip induces negative pitch damping on the aircraft and decreases the value of the pitch dynamic derivative. The missing middle wing causes a noticeable increase in the absolute value of the pitch dynamic derivative;the missing parts on the right wing cause the aircraft to roll to the right side in the dynamic process, and the pitch-roll coupling cross dynamic derivatives are positive. Moreover, the values of these derivatives increase as the damaged area on the right wing increases, and an optimal case with the smallest cross dynamic derivative can be found to help improve the survivability of damaged aircraft.

关键词： Flying wing Fragment damage Continuous rod damage Combined dynamic derivative Computational fluid dynamics(CFD)

Fast FOCUSS method based on bi-conjugate gradient and its application to space-time clutter spectrum estimation

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Science China(Information Sciences) 2017年第8期60卷 163-175页

作者： Gatai bai Ran TAO Juan ZHAO Xia bai Yue WANG School of Mathematics and Statistics Beijing Institute of Technology Beijing Key Laboratory of Fractional Signals and Systems School of Information and Electronics Beijing Institute of Technology

The focal underdetermined system solver(FOCUSS) is a powerful tool for sparse representation in complex underdetermined systems. This paper presents the fast FOCUSS method based on the bi-conjugate gradient(BICG), termed BICG-FOCUSS, to speed up the convergence rate of the original FOCUSS. BICGFOCUSS was specifically designed to reduce the computational complexity of FOCUSS by solving a complex linear equation using the BICG method according to the rank of the weight matrix in FOCUSS. Experimental results show that BICG-FOCUSS is more efficient in terms of computational time than FOCUSS without losing accuracy. Since FOCUSS is an efficient tool for estimating the space-time clutter spectrum in sparse recoverybased space-time adaptive processing(SR-STAP), we propose BICG-FOCUSS to achieve a fast estimation of the space-time clutter spectrum in mono-static array radar and in the mountaintop system. The high performance of the proposed BICG-FOCUSS in the application is demonstrated with both simulated and real data.

关键词： focal underdetermined system solver(FOCUSS) sparse recovery(SR) bi-conjugate gradient(BICG) space-time adaptive processing(STAP) space-time clutter spectrum