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A 1D time-domain method for in-plane wave motions in a layered half-space 被引量:10
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作者 Jingbo Liu Yan Wang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2007年第6期673-680,共8页
A 1D finite element method in time domain is developed in this paper and applied to calculate in-plane wave motions of free field exited by SV or P wave oblique incidence in an elastic layered half-space. First, the l... A 1D finite element method in time domain is developed in this paper and applied to calculate in-plane wave motions of free field exited by SV or P wave oblique incidence in an elastic layered half-space. First, the layered half-space is discretized on the basis of the propagation characteristic of elastic wave according to the Snell law. Then, the finite element method with lumped mass and the central difference method are incorporated to establish 2D wave motion equations, which can be transformed into 1D equations by discretization principle and explicit finite element method. By solving the 1D equations, the displacements of nodes in any vertical line can be obtained, and the wave motions in layered half-space are finally determined based on the characteristic of traveling wave. Both the theoretical analysis and the numerical results demonstrate that the proposed method has high accuracy and good stability. 展开更多
关键词 In-plane wave Oblique incidence time-domain method Snell law
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Perfect plane-wave source for a high-order symplectic finite-difference time-domain scheme
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作者 王辉 黄志祥 +1 位作者 吴先良 任信钢 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第11期365-370,共6页
The method of splitting a plane-wave finite-difference time-domain (SP-FDTD) algorithm is presented for the initiation of plane-wave source in the total-field / scattered-field (TF/SF) formulation of high-order sy... The method of splitting a plane-wave finite-difference time-domain (SP-FDTD) algorithm is presented for the initiation of plane-wave source in the total-field / scattered-field (TF/SF) formulation of high-order symplectic finite- difference time-domain (SFDTD) scheme for the first time. By splitting the fields on one-dimensional grid and using the nature of numerical plane-wave in finite-difference time-domain (FDTD), the identical dispersion relation can be obtained and proved between the one-dimensional and three-dimensional grids. An efficient plane-wave source is simulated on one-dimensional grid and a perfect match can be achieved for a plane-wave propagating at any angle forming an integer grid cell ratio. Numerical simulations show that the method is valid for SFDTD and the residual field in SF region is shrinked down to -300 dB. 展开更多
关键词 splitting plane-wave finite-difference time-domain high-order symplectic finite-differencetime-domain scheme plane-wave source
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Optical simulation of in-plane-switching blue phase liquid crystal display using the finite-difference time-domain method 被引量:1
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作者 窦虎 马红梅 孙玉宝 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第9期117-121,共5页
The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display.Compared with the matrix optic methods and the refractive method,the ... The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display.Compared with the matrix optic methods and the refractive method,the finite-difference timedomain method,which is used to directly solve Maxwell's equations,can consider the lateral variation of the refractive index and obtain an accurate convergence effect.The simulation results show that e-rays and o-rays bend in different directions when the in-plane switching blue phase liquid crystal display is driven by the operating voltage.The finitedifference time-domain method should be used when the distribution of the liquid crystal in the liquid crystal display has a large lateral change. 展开更多
关键词 finite-difference time-domain method blue phase liquid crystal display in-plane switching convergence effect
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考虑车辆稳定的避障路径自适应模型预测跟踪 被引量:1
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作者 陈社会 汤沛 《机械设计与制造》 北大核心 2024年第6期42-47,52,共7页
为了提高车辆在稳定行驶前提下的避障路径跟踪控制精度,设计了自适应模型预测路径跟踪控制器和稳定控制器。根据车辆运动特性,建立了车辆在横向和横摆向共三个自由度的车辆动力学方程;基于路径跟踪控制需要,建立了预瞄跟踪控制模型。在... 为了提高车辆在稳定行驶前提下的避障路径跟踪控制精度,设计了自适应模型预测路径跟踪控制器和稳定控制器。根据车辆运动特性,建立了车辆在横向和横摆向共三个自由度的车辆动力学方程;基于路径跟踪控制需要,建立了预瞄跟踪控制模型。在避障路径跟踪方面,提出了预测时域随车速和路径曲率自适应变化方法;以提高避障路径跟踪精度和控制量增量最小为优化目标,将路径跟踪控制问题转化为二次型问题,实现了自适应优化求解和时域滚动控制。在车辆行驶稳定方面,从车辆状态的稳定性预判、稳定力矩的计算和分配等方面设计了稳定控制器。经仿真验证,这里的方法能够将车辆状态控制在相平面的双线法稳定区域内,实现了车辆行驶的稳定性和安全性;在避障路径跟踪方面,这里的方法的最大跟踪误差和绝对误差均值远小于传统模型预测控制、文献[14]模糊滑模控制,充分证明了这里的方法在避障路径跟踪控制中的高精度和有效性。 展开更多
关键词 避障路径 模型预测控制 自适应预测时域 稳定控制器 相平面
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可扩展的网络验证技术:研究现状与发展趋势
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作者 黄翰林 徐恪 +3 位作者 李琦 李彤 付松涛 高翔宇 《电子学报》 EI CAS CSCD 北大核心 2024年第4期1083-1102,共20页
互联网作为国家信息基础设施的重要组成部分,已经在各个领域发挥着巨大的作用.随着其规模不断扩大和应用持续深入,我们也面临着意图不一致的网络行为可能导致的灾难性危害.为了确保互联网的正常运行和网络行为的一致性,我们迫切需要可... 互联网作为国家信息基础设施的重要组成部分,已经在各个领域发挥着巨大的作用.随着其规模不断扩大和应用持续深入,我们也面临着意图不一致的网络行为可能导致的灾难性危害.为了确保互联网的正常运行和网络行为的一致性,我们迫切需要可部署的网络验证技术,以确保网络运行时的行为与网络运维人员的意图一致.当前已经有许多关于网络验证技术的研究,这些研究帮助用户实现自动检测网络错误,并进一步分析错误产生的原因.然而,为了满足互联网规模不断扩大的需求,可扩展性问题成为在互联网部署网络验证技术的一项重要挑战.即如何在满足时间和空间复杂度约束的前提下,快速发现并排查网络策略的错误,真正将网络验证技术应用于实际,成为一个研究热点.本文从数据面验证和控制面验证两个方面出发,深入研究和总结了现有的网络验证研究工作,并探索了基于时空优化的可扩展性技术,对这些方案的特点进行了系统性分析.最后,本文总结和展望了网络验证可扩展技术的未来研究趋势,为该领域的研究人员提供一定的参考. 展开更多
关键词 网络验证 可扩展性 网络配置 时空优化 数据面验证 控制面验证
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交通公平性导向的平面过街横道信号配时设计
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作者 张倍 杨震 +1 位作者 邬岚 丁玥青青 《物流工程与管理》 2024年第5期64-70,共7页
为了从交通公平性的角度解决平面过街横道的信号配时问题,避免配时结果偏向于机动车,文中首先通过采集平面过街横道几何参数以及交通流量数据,统计获得第15%位行人过街步速;然后基于双环相位结构,考虑相位绿灯时长、行人过街、信号周期... 为了从交通公平性的角度解决平面过街横道的信号配时问题,避免配时结果偏向于机动车,文中首先通过采集平面过街横道几何参数以及交通流量数据,统计获得第15%位行人过街步速;然后基于双环相位结构,考虑相位绿灯时长、行人过街、信号周期等约束条件,以机动车和行人的平均延误之差和机动车平均延误最小为目标,建立平面过街横道的信号配时多目标优化模型,并设计遗传算法求解该模型;最后将求解得到的各种信号配时方案进行对比分析。结果表明:以机动车延误或总平均延误最小为目标,不能得到合理的信号配时结果;当机动车与行人平均延误之差的权重在0.3~0.9时,可以得到两种合理的信号配时结果。因此,以交通公平性为导向的平面过街横道信号配时方法,兼顾了公平性和高效性,在公平地对待每一个交通参与者的同时,也有效地提高了平面过街横道处的通行效率和质量,有利于更公平地分配交通资源,引导交通资源布局向合理化方向发展。 展开更多
关键词 交通工程 信号配时设计 遗传算法 平面过街横道 交通公平 平均延误
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激光3维成像线性焦平面探测器读出电路研究进展
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作者 李雨欣 李潇 +2 位作者 杨赟秀 郑博仁 刘永 《激光技术》 CAS CSCD 北大核心 2024年第5期726-733,共8页
激光焦平面探测器是一种新型的光电成像器件,它利用半导体内部载流子的雪崩倍增效应实现高速、高灵敏度、纳秒级时间分辨探测,用于凝视型激光3维成像系统。探测器主要分为线性和盖革两大类,其中线性模式探测器具有响应速度快、无死时间... 激光焦平面探测器是一种新型的光电成像器件,它利用半导体内部载流子的雪崩倍增效应实现高速、高灵敏度、纳秒级时间分辨探测,用于凝视型激光3维成像系统。探测器主要分为线性和盖革两大类,其中线性模式探测器具有响应速度快、无死时间和后脉冲、可实现单脉冲瞬时成像等优点。首先介绍了在不同应用场景下,线性模式焦平面读出电路的两种架构并简述其原理,然后阐述像素单元的关键电路模块,比较了其优缺点,最后分析了两种减小行走误差的双阈值时刻鉴别方法。为相关领域的研究者提供了一些有益的参考和借鉴。 展开更多
关键词 探测器 线性模式焦平面读出电路 3维成像 光子飞行时间
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考虑割理面时煤层造斜段坍塌压力变化规律研究
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作者 陈颖超 《承德石油高等专科学校学报》 CAS 2024年第1期18-23,共6页
在武威盆地太原组水平井钻进作业时,依据井史数据调研发现,煤层段卡钻、井径扩大、钻具掉落等井壁坍塌导致的井下复杂事故发生,严重制约了煤层气勘探开发的进程。由于煤岩交错割理性(面割理、端割理)弱结构面发育,使煤岩在造斜钻进时井... 在武威盆地太原组水平井钻进作业时,依据井史数据调研发现,煤层段卡钻、井径扩大、钻具掉落等井壁坍塌导致的井下复杂事故发生,严重制约了煤层气勘探开发的进程。由于煤岩交错割理性(面割理、端割理)弱结构面发育,使煤岩在造斜钻进时井壁破坏在力学上呈现为非连续性和非均质性。建立了考虑弱面的井壁坍塌数学模型。通过分析煤岩矿物成分、微宏观结构,确定煤岩井壁坍塌为力学机制占主导因素,得出割理导致的煤岩碎裂成块是井壁失稳的根本原因,建议在后续煤层钻井中优化井眼轨迹、优化钻井液性能进行井壁防塌,并引入煤岩井壁坍塌实时监测系统。 展开更多
关键词 煤岩地层 割理 弱面结构 井壁坍塌 实时监测系统
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Regular nonlinear response of the driven Duffng oscillator to chaotic time series 被引量:3
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作者 袁野 李月 +1 位作者 Danilo P.Mandic 杨宝俊 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第3期958-968,共11页
Nonlinear response of the driven Duffing oscillator to periodic or quasi-periodic signals has been well studied. In this paper, we investigate the nonlinear response of the driven Duffing oscillator to non-periodic, m... Nonlinear response of the driven Duffing oscillator to periodic or quasi-periodic signals has been well studied. In this paper, we investigate the nonlinear response of the driven Duffing oscillator to non-periodic, more specifically, chaotic time series. Through numerical simulations, we find that the driven Duffing oscillator can also show regular nonlinear response to the chaotic time series with different degree of chaos as generated by the same chaotic series generating model, and there exists a relationship between the state of the driven Duffing oscillator and the chaoticity of the input signal of the driven Duffing oscillator. One real-world and two artificial chaotic time series are used to verify the new feature of Duffing oscillator. A potential application of the new feature of Duffing oscillator is also indicated. 展开更多
关键词 Duffing oscillator chaotic time series phase plane diagram largest Lyapunov exponent
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FAST SOLUTION OF TRANSIENT SCATTERING FROM ELECTRICALLY LARGE COMPLEX OBJECTS BASED ON TIME DOMAIN INTEGRAL EQUATION SOLVERS
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作者 Li Ying Ren Meng Zhou Dongming He Jianguo 《Journal of Electronics(China)》 2010年第1期99-104,共6页
A fast Time Domain Integral Equation(TDIE) solver is presented for analysis of transient scattering from electrically large conducting complex objects.The numerical process of Marching-On-in-Time(MOT) method based TDI... A fast Time Domain Integral Equation(TDIE) solver is presented for analysis of transient scattering from electrically large conducting complex objects.The numerical process of Marching-On-in-Time(MOT) method based TDIE encounters high computational cost and exorbitant memory requirements.A group-style accelerated method-Plane Wave Time Domain(PWTD) algorithm,which permits rapid evaluation of transient wave field generated by temporally bandlimited sources,is employed to reduce the computational cost of MOT-based TDIE solvers.An efficient compressed storage technique for sparse matrix is adopted to decrease the enormous memory requirements of MOT.The scheme of the Multi-Level PWTD(MLPWTD)-enhanced MOT with compressed storage for sparse matrix is presented for analysis of transient scattering from electrically large complex objects in this paper.The numerical simulation results demonstrate the validity and efficiency of the presented scheme. 展开更多
关键词 time Domain Integral Equation(TDIE) Marching-On-in-time(MOT) plane Wave time Domain(PWTD) Compressed storage
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Time-history responses on the surface by regularly distributed enormous embedded cavities:Incident SH-waves 被引量:2
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作者 Mehdi Panji Saeed Mojtabazadeh Hasanlouyi 《Earthquake Science》 CSCD 2018年第3期137-153,共17页
The time-history responses of the surface were obtained for a linear elastic half-plane including regularly distributed enormous embedded circular cavities subjected to propagating obliquely incident plane SH-waves. A... The time-history responses of the surface were obtained for a linear elastic half-plane including regularly distributed enormous embedded circular cavities subjected to propagating obliquely incident plane SH-waves. An advanced numerical approach named half-plane time-domain boundary element method(BEM), which only located the meshes around the cavities, was used to create the model. By establishing the modified boundary integral equation(BIE)independently for each cavity and forming the matrices, the final coupled equation was solved step-by-step in the timedomain to obtain the boundary values. The responses were developed for a half-plane with 512 cavities. The amplification patterns were also obtained to illustrate the frequencydomain responses for some cases. According to the results,the presence of enormous cavities affects the scattering and diffraction of the waves arrived to the surface. The introduced method can be recommended for geotechnical/mechanical engineers to model structures in the fields of earthquake engineering and composite materials. 展开更多
关键词 circular cavities half-plane BEM time-history res- ponse SH-wave time-domain wave propagation
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梁系平面刚度偏心分布高桩平台结构地震响应
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作者 李亚 吴兵 《水运工程》 2024年第4期22-27,共6页
基于工程实例,采用反应谱方法、时程分析法对梁系平面刚度偏心分布高桩平台结构地震响应规律进行分析研究。结果发现:横向地震作用下,反应谱法和人工波时程分析法计算结果较为接近,天然波时程分析法结果则因选波呈现差异;桩基二维、三... 基于工程实例,采用反应谱方法、时程分析法对梁系平面刚度偏心分布高桩平台结构地震响应规律进行分析研究。结果发现:横向地震作用下,反应谱法和人工波时程分析法计算结果较为接近,天然波时程分析法结果则因选波呈现差异;桩基二维、三维模型计算结果较为接近,横梁二维、三维模型剪力峰值计算结果接近,弯矩峰值结果差异大。纵向地震作用下,三维反应谱法和人工波时程分析法计算结果接近。不同计算模式对比表明三维反应谱法适应性较好。抗震设防烈度大于7度时,该类型平台结构桩基不宜选用PHC桩。对梁-板连接刚性系数λ进行参数分析表明:λ变化对横梁、纵梁内力的影响大于对桩基的影响,对纵横梁弯矩的影响大于对剪力的影响,且纵向地震作用下影响程度大于横向地震。说明板、梁之间的约束状态改变了结构的刚度分配情况,进而对结构的地震效应产生规律性影响。 展开更多
关键词 高桩平台 平面刚度偏心 地震响应 反应谱法 时程分析法 连接刚性系数
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Amplification of in-plane seismic ground motion by group cavities in layered half-space (Ⅰ) 被引量:2
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作者 Jianwen Liang Ji Zhang Zhenning Ba 《Earthquake Science》 CSCD 2012年第4期275-285,共11页
Amplification of in-plane seismic ground motion by underground group cavities in layered half-space is studied both in frequency domain and time domain by using indirect boundary element method (IBEM), and the effec... Amplification of in-plane seismic ground motion by underground group cavities in layered half-space is studied both in frequency domain and time domain by using indirect boundary element method (IBEM), and the effect of cavity interval and spectrum of incident waves on the amplification are studied by numerical examples. It is shown that there may be large interaction between cavities, and group cavities with certain intervals may have significant amplification to seismic ground motion. The amplification of PGA (peak ground acceleration) and its PRS (peak response spectrum) can be increased up to 45.2% and 84.4%, for an example site in Tianjin, under the excitation of Taft wave and E1 Centro wave; and group cavities may also affect the spectra of the seismic ground motion. It is suggested that the effect of underground group cavities on design seismic ground motion should be considered. 展开更多
关键词 underground group cavity AMPLIFICATION IN-plane seismic ground motion time domain frequency domain indirect boundary element method (IBEM)
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The Transient Solution of Plane Progressive Waves
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作者 Dai Yishan He Wuzhou Professor, Harbin Shipbuilding Engineering Institute, Harbin 150001 Associate Professor, Harbin Shipbuilding Engineering Institute, Harbin 150001 《China Ocean Engineering》 SCIE EI 1993年第3期305-312,共8页
Generated by an ideal sinusoidal motion of the vertical plate, the simplest linear solution in time domain for two-dimensional regular waves is derived. The solution describes the propagation process of the plane prog... Generated by an ideal sinusoidal motion of the vertical plate, the simplest linear solution in time domain for two-dimensional regular waves is derived. The solution describes the propagation process of the plane progressive wave with a front, and will approach the linear steady- state solution as the oscillation time of the plate approaches infinity. The solution presented in this paper can be used to provide an incident wave model with analytical expression for solving the problems of diffraction and response of floating bodies in time domain. 展开更多
关键词 plane progressive wave linear solution time domain analytical expression
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Evaluation of Right Ventricular Volume and Systolic Function by Real-time Three-dimensional Echocardiography 被引量:4
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作者 王静 王新房 +4 位作者 谢明星 杨娅 吕清 杨颖 王良玉 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2005年第1期94-96,99,共4页
The optimal plane for measurement of the right ventricular (RV) volumes by real-time three-dimensional echocardiography (RT3DE) was determined and the feasibility and accuracy of RT3DE in studying RV systolic function... The optimal plane for measurement of the right ventricular (RV) volumes by real-time three-dimensional echocardiography (RT3DE) was determined and the feasibility and accuracy of RT3DE in studying RV systolic function was assessed. RV “Full volume” images were acquired by RT3DE in 22 healthy subjects. RV end-diastolic volumes (RVEDV) and end-systolic volumes (RVESV) were outlined using apical biplane, 4-plane, 8-plane, 16-plane offline separately. RVSV and RVEF were calculated. Meanwhile tricuspid annual systolic excursion (TASE) was measured by M-mode echo. LVSV was outlined by 2-D echo according to the biplane Simpson's rule. The results showed: (1) There was a good correlation between RVSV measured from series planes and LVSV from 2-D echo (r=0.73; r=0.69; r=0.63; r=0.66, P<0.25—0.0025); (2) There were significant differences between RVEDV in biplane and those in 4-, 8-, 16-plane (P<0.001). There was also difference between RV volume in 4-plane and that in 8-plane (P<0.05), but there was no significant difference between RV volume in 8-plane and that in 16-plane (P>0.05); (3) Inter-observers and intro-observers variability analysis showed that there were close agreements and relations for RV volumes (r=0.986, P<0.001; r=0.93, P<0.001); (4) There was a significantly positive correlation of TASE to RVSV and RVEF from RT3DE (r=0.83; r=0.90). So RV volume measures with RT3DE are rapid, accurate and reproducible. In view of RV's complex shape, apical 8-plane method is better in clinical use. It may allow early detection of RV systolic function. 展开更多
关键词 real-time three-dimensional echocardiography right ventricular volume apical 8-plane right ventricular systolic function
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随机通信时延下传感器连通覆盖保持算法研究 被引量:1
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作者 郭彩萍 《传感技术学报》 CAS CSCD 北大核心 2023年第1期147-152,共6页
随机通信环境下传感网络节点信息传输随机性较强,导致传感器网络的连通覆盖难以保持。为此,提出基于模拟二维分析的传感器连通覆盖保持算法。标记传感器感知范围内任意一个节点形成的感知圆,以该圆作为传感器对该节点的初步覆盖范围,分... 随机通信环境下传感网络节点信息传输随机性较强,导致传感器网络的连通覆盖难以保持。为此,提出基于模拟二维分析的传感器连通覆盖保持算法。标记传感器感知范围内任意一个节点形成的感知圆,以该圆作为传感器对该节点的初步覆盖范围,分别计算该节点、相邻节点端与传感器端间接收到能量的起始时间,构建不同时延量对节点实际覆盖度、覆盖面积以及覆盖概率的影响模型。获取单节点与整个区域的覆盖范围重叠部分,根据串联覆盖路径连通覆盖法约束传感器节点,实现连通及覆盖的保持。设置通信时延为5 m/s和20 m/s,设计仿真实验。实验结果验证了所提方法受到时延环境的影响较小,且耗时更短,适应能力强,连通覆盖保持的范围更广。该方法具有实际应用价值。 展开更多
关键词 传感器连通覆盖 串联覆盖路径 二维平面分析法 随机通信时延环境 二维平面分析 时延量 感知范围
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Design and Imaging Application of Room-Temperature Terahertz Detector with Micro-Bolometer Focal Plane Array
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作者 Jun Wang Jun Gou +1 位作者 Zhi-Ming Wu Ya-Dong Jiang 《Journal of Electronic Science and Technology》 CAS CSCD 2016年第2期98-102,共5页
Room-temperature terahertz (THz) detectors indicate a great potential in the imaging application because of their real-time, compact bulk, and wide spectral band responding characteristics. THz detectors with differ... Room-temperature terahertz (THz) detectors indicate a great potential in the imaging application because of their real-time, compact bulk, and wide spectral band responding characteristics. THz detectors with different dimensions based on a micro-bridge structure have been designed and fabricated to get optimized micro-bolometer parameters from the test results of membrane deformation. A nanostructured titanium (Ti) thin film absorber is integrated in the micro-bridge structure of the VOx micro-bolometer by a combined process of magnetron sputtering and reactive ion etching (RIE), and its improvement of THz absorption is verified by an optical characteristics mesurement. Continuous-wave THz detection and imaging are demonstrated by using a 2.52 THz far infrared CO2 laser and a 320x240 vanadium oxide micro-bolometer focal plane array with an optimized cell structure. With this detecting system, THz imaging of metal concealed in a wiping cloth and an envelope is demonstrated, respectively. 展开更多
关键词 Index Terms---Focal plane array micro-bolometer structure real-time imaging room temperatureterahertz detector
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基于LSTM和改进TTR算法的车辆辅助驾驶侧翻预警
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作者 周兵 梁帅 +3 位作者 吴晓建 许艳 潘倩兮 柴天 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2023年第12期155-167,共13页
以提高侧翻预警中对侧翻风险的预测和判断为目标,为了给驾驶员或其他驾驶辅助系统确定对车辆进行控制的介入时机提供重要依据,提出了一种更高效准确的侧翻预警算法.首先建立三自由度车辆预警参考模型;选取相平面法划分侧倾稳定域为侧翻... 以提高侧翻预警中对侧翻风险的预测和判断为目标,为了给驾驶员或其他驾驶辅助系统确定对车辆进行控制的介入时机提供重要依据,提出了一种更高效准确的侧翻预警算法.首先建立三自由度车辆预警参考模型;选取相平面法划分侧倾稳定域为侧翻指标,根据三自由度模型响应,设计改进侧翻预测时间(TTR)算法并计算TTR.分析结果表明,相平面侧翻指标接近实际横向载荷转移率(LTR),比LTR常用的表达形式更准确地表述了车辆状态,且改进的TTR也更加接近实际TTR.然后建立长短期记忆网络(LSTM)模型来取代改进TTR算法,提高预警计算效率,模型输出的TTR值作为车辆预警控制的依据.最后通过驾驶员在环(DIL)试验采集数据,对LSTM模型进行训练,并在两种工况下,仿真验证了此侧翻预警方法具有对侧翻风险预测的准确性和更高的实时性. 展开更多
关键词 高级驾驶辅助系统 侧翻预警 改进侧翻预测时间算法 相平面法 长短期记忆网络
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一类平面弹性问题的有限元分析
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作者 熊敏 权晓曦 +2 位作者 王娟 李昊天 曹一骄 《成都航空职业技术学院学报》 2023年第1期70-71,75,共3页
针对一类平面弹性振动问题提出了一种新的时空有限元方法。针对此弹性问题,对位移在时间上采用连续元,空间上采用非协调不完全二次矩形有限元进行离散,提出了变分有限元格式。证明了此格式解的存在唯一性,给出了误差估计,并用数值算例... 针对一类平面弹性振动问题提出了一种新的时空有限元方法。针对此弹性问题,对位移在时间上采用连续元,空间上采用非协调不完全二次矩形有限元进行离散,提出了变分有限元格式。证明了此格式解的存在唯一性,给出了误差估计,并用数值算例验证了理论结果。此方法能改进时空有限元方法在数值实验中计算量大的问题。 展开更多
关键词 平面弹性问题 时空有限元 存在唯一性 误差估计
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迭代重加权时域平面波叠加法的非稳态声场重建
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作者 耿林 周玲枝 +1 位作者 陈兴国 谢峰 《声学学报》 EI CAS CSCD 北大核心 2023年第2期347-355,共9页
提出了迭代重加权时域平面波叠加法,并应用于非稳态声场重建。该方法首先通过时域离散卷积得到全息面时域声压与虚源面时域波数谱离散状态公式;然后根据稀疏表示和迭代重加权,得到残差范数与加权解范数最小化问题表达式;最后将每一对波... 提出了迭代重加权时域平面波叠加法,并应用于非稳态声场重建。该方法首先通过时域离散卷积得到全息面时域声压与虚源面时域波数谱离散状态公式;然后根据稀疏表示和迭代重加权,得到残差范数与加权解范数最小化问题表达式;最后将每一对波数下虚源面时域波数谱与时域传播核卷积叠加得到重建面上的时域声压。为了验证该方法的有效性,给出了激励板声源的仿真验证,并在半消声室内进行了实验验证。讨论了一些参数对该方法的影响,并通过与基于Tikhonov正则化的时域平面波叠加法比较,突出该方法的重建优势。仿真和实验结果表明,该方法对非稳态声场重建具有很好的效果,并且重建精度高。 展开更多
关键词 时域平面波叠加 稀疏表示 非稳态声场 声场重建
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