导航系统依赖传感器感知周围环境。当前,基于单一传感器的导航系统已难以满足各类复杂场景下的导航需求,导航系统正朝传感器多源化方向发展。在多源传感器数据融合过程中,图像数据的处理最消耗时间和资源,对系统性能影响最大。为解决这...导航系统依赖传感器感知周围环境。当前,基于单一传感器的导航系统已难以满足各类复杂场景下的导航需求,导航系统正朝传感器多源化方向发展。在多源传感器数据融合过程中,图像数据的处理最消耗时间和资源,对系统性能影响最大。为解决这些问题,设计智能导航平台的硬件控制终端,利用基于全球卫星导航系统(Global Navigation Satellite System,GNSS)秒脉冲(Pulse Per Second,PPS)的时间同步,实现多源传感器数据融合;设计用于同步定位与地图构建(Simultaneous Localization And Mapping,SLAM)前端ORB(Oriented FAST and Rotated BRIEF)特征提取加速器,加速图像处理过程,提高SLAM系统的实时性。实验结果表明,硬件平台不仅支持GNSS、惯性测量单元(Inertial Measurement Unit,IMU)、视觉和激光雷达的数据采集和融合,还能加速图像ORB特征点提取。在执行图像ORB特征提取任务时,与CPU和GPU平台上的实现相比,该加速器的帧率分别达到了它们的2.7倍和1.8倍,而功耗仅为它们的5.1%和2.9%。展开更多
In the context of the global energy low-carbon transition,phase change energy storage technology becomes a key technology to solve the problem of intermittent renewable energy.Oriented phase change composites(OCPCMs)r...In the context of the global energy low-carbon transition,phase change energy storage technology becomes a key technology to solve the problem of intermittent renewable energy.Oriented phase change composites(OCPCMs)receive widespread attention in practical energy storage applications due to their unique oriented thermally conductive structure,which achieves significant thermal conductivity enhancement in specific directions while retaining the high energy storage capacity of the phase change components.This review systematically summarizes the overall analysis of OCPCMs from synthesis and preparation to application scenarios in recent years.Herein,we introduce the analysis of the heat transfer mechanism of the materials and explore the advantages of the oriented structure in OCPCMs in the heat transfer behavior from a bionic perspective.We then focus on summarizing and generalizing the methods for preparing OCPCMs,giving suggestions for suitable methods according to different scenarios.Besides,we discuss the application of finite element simulation methods to the monitoring of the thermal management behavior of OCPCMs,and look into the potential future application areas of such materials.Finally,it is hoped that this review will provide guidance for the academic community in developing high-performance OCPCMs.展开更多
Systematically analyzing the impact mechanisms of policy on Land Use Conflict(LUC)is crucial for constructing effective conflict mitigation strategies.However,previous research on how policy influences LUC remains rel...Systematically analyzing the impact mechanisms of policy on Land Use Conflict(LUC)is crucial for constructing effective conflict mitigation strategies.However,previous research on how policy influences LUC remains relatively limited.Focusing on the indirect driving role of policy on LUC,this study proposed County Development Level(CDL)under Major Function Oriented Zone Planning(MFOZP)guidance as an intermediary variable,bridging the implicit influence of MFOZP and the explicit changes in LUC.Using the Beijing-Tianjin-Hebei(BTH)region in China as a case study,we analyzed the spatio-temporal evolution characteristics of LUC and CDL for the periods 2000-2010 and 2010-2020,before and after MFOZP implementation.Panel models and Geographically Weighted Regression(GWR)were employed to explore the mechanism by which CDL influences LUC under MFOZP guidance.The results show that:1)MFOZP implementation effectively alleviates land use pressure from regional development,with LUC continuously declining at a rate of 2.41%,while CDL exhibits slight growth(3.84%),during 2010-2020.2)Under MFOZP guidance,CDL reduces pressure on Land Use Structure Conflict(LUSC)and Land Use Process Conflict(LUPC),enhances its inhibitory effect on Land Use Function Conflict(LUFC),and significantly contributes to LUC coordination,with notable spatial heterogeneity.3)The coupling relationship between CDL and LUC has improved post-implementation.Based on this,tailored LUC coordination strategies are proposed for different functional zones.This study confirms the effectiveness of MFOZP in coordinating LUC and provides a scientific reference for LUC research under policy frameworks and the governance of LUC in the BTH region.展开更多
为了提高图像拼接速度并满足高分辨率图像的实时拼接需求,提出了一种基于ORB(Oriented Fast and Rotated Brief)算法和MSAC(M-estimator Sample Consensus)算法的快速图像拼接方法。ORB算法特征匹配速度快,能够满足实时性要求。首先采用...为了提高图像拼接速度并满足高分辨率图像的实时拼接需求,提出了一种基于ORB(Oriented Fast and Rotated Brief)算法和MSAC(M-estimator Sample Consensus)算法的快速图像拼接方法。ORB算法特征匹配速度快,能够满足实时性要求。首先采用ORB算法进行图像特征点提取;然后,采用MSAC算法对匹配点对进行优化,剔除图像拼接中的伪匹配点对,通过正确的匹配点对求解图像变换矩阵;最后,采用双线性插值融合算法消除可见接缝并去除拼接痕迹。实验结果表明,本文方法在保证图像拼接质量的同时具有更快的拼接速度。展开更多
利用计算机视觉对桥梁结构进行位移测量,常见的方法有特征点算法和光流法。为解决光照变化对光流法的精度影响,以及特征点法难以对目标进行实时跟踪等问题,以定向FAST与旋转BRIEF(oriented FAST and rotated BRIEF,ORB)特征点算法提取...利用计算机视觉对桥梁结构进行位移测量,常见的方法有特征点算法和光流法。为解决光照变化对光流法的精度影响,以及特征点法难以对目标进行实时跟踪等问题,以定向FAST与旋转BRIEF(oriented FAST and rotated BRIEF,ORB)特征点算法提取目标特征点,并结合LK(Lucas-Kanade)光流法进行跟踪。通过两种算法的互补融合,并设定周期性更新策略,有效减少误差积累。在室内进行了钢板梁模型激振试验,探讨光照变化对算法性能的影响。将算法得到的位移数据与激光位移计测量结果进行对比,以验证其准确性。此外,还将该算法与FAST-LK、SIFT-LK、Shi-Tomasi-LK、siamRPN++等算法进行比对分析。结果表明:该算法得到的位移曲线拟合程度在95%以上,误差控制在5%之内,验证了其可行性,同时,试验表明该方法对光照变化具有一定的鲁棒性,并能达到实时性的要求。展开更多
文摘导航系统依赖传感器感知周围环境。当前,基于单一传感器的导航系统已难以满足各类复杂场景下的导航需求,导航系统正朝传感器多源化方向发展。在多源传感器数据融合过程中,图像数据的处理最消耗时间和资源,对系统性能影响最大。为解决这些问题,设计智能导航平台的硬件控制终端,利用基于全球卫星导航系统(Global Navigation Satellite System,GNSS)秒脉冲(Pulse Per Second,PPS)的时间同步,实现多源传感器数据融合;设计用于同步定位与地图构建(Simultaneous Localization And Mapping,SLAM)前端ORB(Oriented FAST and Rotated BRIEF)特征提取加速器,加速图像处理过程,提高SLAM系统的实时性。实验结果表明,硬件平台不仅支持GNSS、惯性测量单元(Inertial Measurement Unit,IMU)、视觉和激光雷达的数据采集和融合,还能加速图像ORB特征点提取。在执行图像ORB特征提取任务时,与CPU和GPU平台上的实现相比,该加速器的帧率分别达到了它们的2.7倍和1.8倍,而功耗仅为它们的5.1%和2.9%。
基金financially supported by the Fundamental Research Funds for the Central Universities(No.FRF-KST-25-001)the Beijing Natural Science Foundation(No.L253029)。
文摘In the context of the global energy low-carbon transition,phase change energy storage technology becomes a key technology to solve the problem of intermittent renewable energy.Oriented phase change composites(OCPCMs)receive widespread attention in practical energy storage applications due to their unique oriented thermally conductive structure,which achieves significant thermal conductivity enhancement in specific directions while retaining the high energy storage capacity of the phase change components.This review systematically summarizes the overall analysis of OCPCMs from synthesis and preparation to application scenarios in recent years.Herein,we introduce the analysis of the heat transfer mechanism of the materials and explore the advantages of the oriented structure in OCPCMs in the heat transfer behavior from a bionic perspective.We then focus on summarizing and generalizing the methods for preparing OCPCMs,giving suggestions for suitable methods according to different scenarios.Besides,we discuss the application of finite element simulation methods to the monitoring of the thermal management behavior of OCPCMs,and look into the potential future application areas of such materials.Finally,it is hoped that this review will provide guidance for the academic community in developing high-performance OCPCMs.
基金Under the auspices of the National Key Research and Development Program of China(No.2018YFD1100803)the Fundamental Research Fund for the Central Universities(Ph.D.Top Innovative Talents Fund of CUMTB)(No.BBJ2024029)。
文摘Systematically analyzing the impact mechanisms of policy on Land Use Conflict(LUC)is crucial for constructing effective conflict mitigation strategies.However,previous research on how policy influences LUC remains relatively limited.Focusing on the indirect driving role of policy on LUC,this study proposed County Development Level(CDL)under Major Function Oriented Zone Planning(MFOZP)guidance as an intermediary variable,bridging the implicit influence of MFOZP and the explicit changes in LUC.Using the Beijing-Tianjin-Hebei(BTH)region in China as a case study,we analyzed the spatio-temporal evolution characteristics of LUC and CDL for the periods 2000-2010 and 2010-2020,before and after MFOZP implementation.Panel models and Geographically Weighted Regression(GWR)were employed to explore the mechanism by which CDL influences LUC under MFOZP guidance.The results show that:1)MFOZP implementation effectively alleviates land use pressure from regional development,with LUC continuously declining at a rate of 2.41%,while CDL exhibits slight growth(3.84%),during 2010-2020.2)Under MFOZP guidance,CDL reduces pressure on Land Use Structure Conflict(LUSC)and Land Use Process Conflict(LUPC),enhances its inhibitory effect on Land Use Function Conflict(LUFC),and significantly contributes to LUC coordination,with notable spatial heterogeneity.3)The coupling relationship between CDL and LUC has improved post-implementation.Based on this,tailored LUC coordination strategies are proposed for different functional zones.This study confirms the effectiveness of MFOZP in coordinating LUC and provides a scientific reference for LUC research under policy frameworks and the governance of LUC in the BTH region.
文摘为了提高图像拼接速度并满足高分辨率图像的实时拼接需求,提出了一种基于ORB(Oriented Fast and Rotated Brief)算法和MSAC(M-estimator Sample Consensus)算法的快速图像拼接方法。ORB算法特征匹配速度快,能够满足实时性要求。首先采用ORB算法进行图像特征点提取;然后,采用MSAC算法对匹配点对进行优化,剔除图像拼接中的伪匹配点对,通过正确的匹配点对求解图像变换矩阵;最后,采用双线性插值融合算法消除可见接缝并去除拼接痕迹。实验结果表明,本文方法在保证图像拼接质量的同时具有更快的拼接速度。
文摘利用计算机视觉对桥梁结构进行位移测量,常见的方法有特征点算法和光流法。为解决光照变化对光流法的精度影响,以及特征点法难以对目标进行实时跟踪等问题,以定向FAST与旋转BRIEF(oriented FAST and rotated BRIEF,ORB)特征点算法提取目标特征点,并结合LK(Lucas-Kanade)光流法进行跟踪。通过两种算法的互补融合,并设定周期性更新策略,有效减少误差积累。在室内进行了钢板梁模型激振试验,探讨光照变化对算法性能的影响。将算法得到的位移数据与激光位移计测量结果进行对比,以验证其准确性。此外,还将该算法与FAST-LK、SIFT-LK、Shi-Tomasi-LK、siamRPN++等算法进行比对分析。结果表明:该算法得到的位移曲线拟合程度在95%以上,误差控制在5%之内,验证了其可行性,同时,试验表明该方法对光照变化具有一定的鲁棒性,并能达到实时性的要求。
