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采用飞行时间相机的瞬态成像及其应用

Jing-yu Lin, Ri-hui Wu, Hong-man Wang, Ye-bin Liu,jylin@gxu.edu.cn,liuyebin@tsinghua.edu.cn

《信息与电子工程前沿(英文)》 2017年 第18卷 第9期   页码 1268-1276 doi: 10.1631/FITEE.1700556

摘要: 介绍了采用飞行时间(time-of-flight, ToF)相机进行瞬态成像的三种数学模型,即相关函数模型、频域模型和压缩感知模型。瞬态图像应用主要基于光传输解析和不同光路光线分离。

关键词: 瞬态成像;飞行时间(time-of-flight     ToF);散射介质;拐角遮挡    

Transient imaging with a time-of-flight cameraand its applications

Jing-yu LIN, Ri-hui WU, Hong-man WANG, Ye-bin LIU

《信息与电子工程前沿(英文)》 2017年 第18卷 第9期   页码 1268-1276 doi: .org/10.1631/FITEE.1700556

摘要: Transient imaging is a technique in photography that recordsthe process of light propagation before it reaches a stationary statesuch that events at the light speed level can be observed. In thisreview we introduce three main models for transient imaging with atime-of-flight (ToF) camera: correlation model, frequency-domain model,and compressive sensing model. Transient imaging applications usuallyinvolve resolving the problem of light transport and separating thelight rays arriving along different paths. We discuss two of the applications:imaging objects inside scattering media and recovering both the shapeand texture of an object around a corner.

关键词: Transient imaging     Time-of-flight(ToF) camera     Scattering media     Around corners    

Determination of persistent organic pollutants by gas chromatography/laser multiphoton ionization/time-of-flight

Osamu SHITAMICHI, Taiki MATSUI, Yamei HUI, Weiwei CHEN, Totaro IMASAKA

《环境科学与工程前沿(英文)》 2012年 第6卷 第1期   页码 26-31 doi: 10.1007/s11783-011-0374-7

摘要: An authentic mixture of polychlorinated biphenyls was measured using a short wide-bore capillary column for the group separation of major components present in an actual sample of Kanechlor. The limits of detection were improved by ca. 2 fold in comparison with those obtained using a conventional capillary column, since the retention time was reduced and the amount of analytes introduced into the mass spectrometer per unit time could be increased. On the other hand, surface-water and sediment samples containing polycyclic aromatic hydrocarbons (PAHs) were collected from the river located in the vicinity of a waste water treatment plant. Even acenaphthylene, a minor component of the mixture could be measured for the sediment sample, and the concentrations were determined for several heavy PAHs. As demonstrated, a technique involving laser multiphoton ionization/time-of-flight mass spectrometry was useful as a sensitive and selective analytical tool for the trace analysis of persistent organic pollutants in an environmental sample.

关键词: polychlorinated biphenyls (PCBs)     polycyclic aromatic hydrocarbons (PAHs)     laser multiphoton ionization/time-of-flight mass spectrometry (MPI/TOF-MS)    

Characterization of submicron aerosols in the urban outflow of the central Pearl River Delta region of China

Zhaoheng GONG, Zijuan LAN, Lian XUE, Liwu ZENG, Lingyan HE, Xiaofeng HUANG

《环境科学与工程前沿(英文)》 2012年 第6卷 第5期   页码 725-733 doi: 10.1007/s11783-012-0441-8

摘要: Submicron aerosol particles (with aerodynamic diameters less than 1 μm, PM ) were sampled and measured in Heshan, an urban outflow site of Guangzhou megacity in Pearl River Delta in South China, using an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) in November 2010 during 2010 Guangzhou Asian Games. The mean PM mass concentration measured was 47.9±17.0 μg·m during the campaign, with organic aerosol (OA) and sulfate being the two dominant species, accounting for 36.3% and 20.9% of the total mass, respectively, followed by black carbon (17.1%, measured by an aethalometer), nitrate (12.9%), ammonium (9.6%) and chloride (3.1%). The average size distributions of the species (except black carbon) were dominated by an accumulation mode peaking at ~550 nm. Calculations based on high-resolution organic mass spectrum showed that, C, H, O and N on average contributed 58.1%, 7.3%, 30.7%, and 3.9% to the total organic mass, respectively. The average ratio of organic mass over organic carbon mass (OM/OC) was 1.73±0.08. Four components of OA were identified by the Positive Matrix Factorization (PMF) analysis, including a hydrocarbon-like (HOA), a biomass burning (BBOA) and two oxygenated (SV-OOA and LV-OOA) organic aerosol components, which on average accounted for 18.0%, 14.3%, 28.8% and 38.9% of the total organic mass, respectively.

关键词: organic aerosol     high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS)     positive matrix factorization    

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0705-3

摘要: As a nondestructive testing technique, terahertz time-domain spectroscopy technology is commonly used to measure the thickness of ceramic coat in thermal barrier coatings (TBCs). However, the invisibility of ceramic/thermally grown oxide (TGO) reflective wave leads to the measurement failure of natural growth TGO whose thickness is below 10 μm in TBCs. To detect and monitor TGO in the emergence stage, a time of flight (TOF) improved TGO thickness measurement method is proposed. A simulative investigation on propagation characteristics of terahertz shows the linear relationship between TGO thickness and phase shift of feature wave. The accurate TOF increment could be acquired from wavelet soft threshold and cross-correlation function with negative effect reduction of environmental noise and system oscillation. Thus, the TGO thickness could be obtained efficiently from the TOF increment of the monitor area with different heating times. The averaged error of 1.61 μm in experimental results demonstrates the highly accurate and robust measurement of the proposed method, making it attractive for condition monitoring and life prediction of TBCs.

关键词: thermal barrier coatings     thermally grown oxide     terahertz spectroscopy     time of flight    

Single particle analysis of ambient aerosols in Shanghai during the World Exposition, 2010: two case studies

Shikang TAO, Xinning WANG, Hong CHEN, Xin YANG, Mei LI, Lei LI, Zhen ZHOU

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 391-401 doi: 10.1007/s11783-011-0355-x

摘要: A TSI Model 3800 aerosol time-of-flight mass spectrometer (ATOFMS) was deployed for single-particle analysis in Shanghai during the World Exposition (EXPO), 2010. Measurements on two extreme cases: polluted day (1st May) and clean day (25th September) were compared to show how meteorological conditions affected the concentration and composition of ambient aerosols. Mass spectra of 90496 and 50407 particles were analyzed respectively during the two sampling periods. The ART-2a neural network algorithm was applied to sort the collected particles. Seven major classes of particles were obtained: dust, sea salt, industrial, biomass burning, organic carbon (OC), elementary carbon (EC), and NH -rich particles. Number concentration of ambient aerosols showed a strong anti-correlation with the boundary layer height variation. The external mixing states of aerosols were quite different during two sampling periods because of different air parcel trajectories. Number fraction of biomass burning particles (43.3%) during polluted episode was much higher than that (21.6%) of clean time. Air parcels from the East China Sea on clean day diluted local pollutant concentration and increased the portion of sea salt particle dramatically (13.3%). The large contribution of biomass burning particles in both cases might be an indication of a constant regional background of biomass burning emission. Mass spectrum analysis showed that chemical compositions and internal mixing states of almost all the particle types were more complicate during polluted episode compared with those observed in clean time. Strong nitrate signals in the mass spectra suggested that most of the particles collected on polluted day had gone through some aging processes before reaching the sampling site.

关键词: ambient aerosol     aerosol time-of-flight mass spectrometer     Shanghai     world exposition    

基于普通器件实现快1000倍的相机与机器视觉 Article

Tiejun Huang, Yajing Zheng, Zhaofei Yu, Rui Chen, Yuan Li, Ruiqin Xiong, Lei Ma, Junwei Zhao, Siwei Dong, Lin Zhu, Jianing Li, Shanshan Jia, Yihua Fu, Boxin Shi, Si Wu, Yonghong Tian

《工程(英文)》 2023年 第25卷 第6期   页码 110-119 doi: 10.1016/j.eng.2022.01.012

摘要:

在数码相机中,我们发现了一个重大缺陷,即从胶片相机继承的图像和视频模型阻碍了相机捕捉快速变化的光子世界。我们提出了一种新的视觉形式,称为视象(vform),这是一个比特序列阵列,其中每个比特表示光子的累积是否达到了一个阈值,从而可以记录和重建任何时刻场景的光强。仅使用消费级CMOS传感器和集成电路,开发了一种比传统相机快1000倍的脉冲相机。将视象看作生物视觉中的脉冲序列,进一步开发了基于脉冲神经网络的机器视觉系统,它可以将机器的速度和生物视觉的机理结合起来,从而实现了比人类视觉快1000倍的高速目标检测和跟踪,并通过辅助裁判和目标瞄准系统证明了脉冲相机和超级视觉系统的效用。视象模型和芯片有望从根本上改变图像和视频的概念以及摄影、电影和视觉媒体等相关行业,并开启一个全新的基于脉冲神经网络的速度自由的机器视觉时代。

关键词: Vidar相机     脉冲神经网络     超级视觉系统     全时成像    

适用于大视场红外地球敏感器的相机标定方法 Research Article

邓华健1,2,王昊1,2,韩晓亚3,刘洋1,2,金仲和1,2

《信息与电子工程前沿(英文)》 2023年 第24卷 第1期   页码 141-153 doi: 10.1631/FITEE.2200079

摘要: 相机的几何精度不足是制约大视场红外地球敏感器精度提升的主要因素。红外地球敏感器相机超大的视场与中心的盲区极大地限制了传统几何标定方法的准确性与可行性。本文提出并验证了一种新型的适用于红外地球敏感器的相机标定方法。三个红外靶标被用作控制点,而相机被安装于双轴转台上。随着转台的旋转,这些控制点将均匀地分布在整个相机视场中。与传统的平行光管与转台配合方法相比,传统方法无法有效覆盖大视场且需要苛刻的实验设备,而该方法更易于实施且成本较低。本文还提出了相应的三步参数估计算法,从而不需要精确测量相机和控制点的位置。本文用10台红外地球敏感器进行了实验,以验证标定方法的有效性。结果表明,所提出的方法是高度稳定可靠的,标定精度与现有其他方法相比提升至少30%。

关键词: 红外地球敏感器;全景红外相机;相机标定    

航空航天技术与力学

陈士橹

《中国工程科学》 2003年 第5卷 第3期   页码 25-26

摘要:

文章论述了航空航天技术发展与力学学科发展的依存关系,讨论了力学学科间的交叉及交叉学科的产生,重点介绍了飞行力学与空气动力学、结构力学、一般力学、自动控制等学科间的关系,进而讨论了飞行力学的分支——弹性飞行器动力学。

关键词: 空气动力学     结构力学     一般力学     自动控制     飞行力学     弹性飞行器动力学    

Response surface regression analysis on FeCrBSi particle in-flight properties by plasma spray

Runbo MA,Lihong DONG,Haidou WANG,Shuying CHEN,Zhiguo XING

《机械工程前沿(英文)》 2016年 第11卷 第3期   页码 250-257 doi: 10.1007/s11465-016-0401-2

摘要:

This work discusses the interactive effects between every two of argon flow rate, voltage, and spray distance on in-flight particles by plasma spray and constructs models that can be used in predicting and analyzing average velocity and temperature. Results of the response surface methodology show that the interactive effects between voltage and spray distance on particle in-flight properties are significant. For a given argon flow rate, particle velocity and temperature response surface are obviously bending, and a saddle point exists. With an increase in spray distance, the interactive effects between voltage and argon flow rate on particle in-flight properties appear gradually and then weaken. With an increase in voltage, the interactive effects between spray distance and argon flow rate on particle in-flight properties change from appearing to strengthening and then to weakening.

关键词: particle velocity     particle temperature     interactive effects     response surface    

β-粒子在穿越铜狭缝中的横向台阶分布

朱永强,郝建宇

《中国工程科学》 2008年 第10卷 第8期   页码 81-86

摘要:

文章研究了电子高速运动时所产生的横向振动。实验方法是利用半圆聚焦β-谱仪上90Sr源β-粒子在不同磁场下对于相同弯曲半径下β-粒子具有不同的能量和动量的特性,研究这些β-粒子在通过不同宽度的铜狭缝(厚8 mm)时的粒子数n和铜狭缝宽度δ的函数关系,发现不管β-粒子具有什么能量和动量,都具有横向运动的趋势和在铜狭缝中出现了台阶分布。其原因可能是β-粒子本身具有横向振幅A和周围真空起伏能量的相互作用。

关键词: β-粒子的横向振动     铜狭缝宽度     横向台阶分布    

Comparative proteomic analysis of cold responsive proteins in two wheat cultivars with different tolerance to spring radiation frost

Shujuan ZHANG,Guoqi SONG,Yulian LI,Jie GAO,Jiao WANG,Guiju CHEN,Haosheng LI,Genying LI,Zhendong ZHAO

《农业科学与工程前沿(英文)》 2014年 第1卷 第1期   页码 37-45 doi: 10.15302/J-FASE-2014008

摘要: Spring radiation frost (SRF) is a severe environmental stress which impairs wheat yield and productivity worldwide. To better understand the mechanism of wheat ( ) responding to SRF, a comparative proteomic analysis was performed to analyze the changes of the key proteins in two wheat cultivars Jimai22 and Luyuan301 with high and low tolerance to SRF respectively. A total of 43 differentially expressed proteins (DEPs) which mainly involved in carbohydrate metabolism, amino acid metabolism, resistance proteins and antioxidant enzymes, photosynthesis and cellular respiration proteins, cell-wall related proteins, protein translation/processing/degradation and signal transduction were isolated and identified by two-dimensional electrophoresis and MALDI-TOF-TOF MS. The results revealed that of the 21 DEPs in Jimai22 responding to the SRF, 13 DEPs were upregulated and 8 DEPs were downregulated, and that of the 22 DEPs in Luyuan301, 9 DEPs were upregulated and 13 DEPs were downregulated. These DEPs might be responsible for the stronger cold resistance of Jimai22 compared to Luyuan301. The expression pattern and function analysis of these DEPs were very significant to understanding the mechanism of the SRF responses in wheat.

关键词: common wheat     spring radiation frost     proteomic analysis     2-DE     MALDI-TOF-TOF MS    

多孔径光学成像系统及其光场采集数学模型 Review Article

祁启明,傅瑞罡,邵铮铮,王平,范红旗

《信息与电子工程前沿(英文)》 2022年 第23卷 第6期   页码 823-844 doi: 10.1631/FITEE.2100058

摘要:

受昆虫复眼启发,为提高光学成像质量,如获得高分辨率图像或大视场图像,研究者提出了许多多孔径光学成像系统。光场采集数学模型是联系多孔径光学成像系统结构设计与应用的纽带,但光场采集数学模型较少被关注。本文系统梳理了典型多孔径光学成像系统(仿生复眼、光场相机、相机阵列),总结了不同结构下多孔径光学成像系统的一般性光场采集数学模型。列出的数学模型既可用于计算特定多孔径光学成像系统的关键指标,如视场大小和子图像重叠比等,也可作为数学工具,便于研究者完成对成像系统的定量设计与评估。

关键词: 多孔径光学成像系统;仿生复眼;光场相机;相机阵列;光场采集模型    

HY-2A卫星雷达高度计设计及其在轨工作结果

许可,刘和光,姜景山

《中国工程科学》 2013年 第15卷 第7期   页码 25-32

摘要:

海洋二号(HY-2A)卫星是我国第一颗海洋动力环境卫星,雷达高度计是HY-2A卫星的主载荷之一,发射入轨后仪器工作正常,并获得了大量有效的观测数据。该仪器在20 m有效波高条件下测高精度达到了4 cm,在4 m有效波高条件下测高精度达到了2 cm,其产品精度接近Jason-2卫星高度计。本文就HY-2A卫星雷达高度计系统设计和在轨初步结果进行论述。

关键词: 雷达高度计     HY-2A卫星     在轨工作    

基于张量因子分解框架的航班延误模式分析 Article

张明远, 陈莘文, 孙立君, 杜文博, 曹先彬

《工程(英文)》 2021年 第7卷 第4期   页码 465-472 doi: 10.1016/j.eng.2020.08.024

摘要:

在空中交通管理和民航机场运营过程中,从过去的运营中获得的经验对于设计合理的策略至关重要。因此,本文使用大量时空飞行数据来识别相似的航空交通和延误模式,这对于更好地了解航空系统和制订管理决策至关重要。但是,由于数据集隐含了复杂的依赖关系以及高维时空之间的交互作用,因此挖掘数据中的重要特征和模式非常具有挑战性。本文提出了高维历史飞行数据的张量因子分解框架。我们通过潜在类别分析模型,并使用2014—2017年中国224个机场的空中交通运行数据证明了该框架的有效性。研究发现每个维度可以清晰地代表不同的运行模式。为了证明这些模式的有效性,我们创建了一个估计模型,该模型可实现对航班延误程度的初步判断。上述结果可以根据历史情景获得的经验,帮助机场运营商和空中交通管理人员更好地了解空中交通和延误模式。

关键词: 空中交通管理     航班延误     潜在类别模型     张量分解    

标题 作者 时间 类型 操作

采用飞行时间相机的瞬态成像及其应用

Jing-yu Lin, Ri-hui Wu, Hong-man Wang, Ye-bin Liu,jylin@gxu.edu.cn,liuyebin@tsinghua.edu.cn

期刊论文

Transient imaging with a time-of-flight cameraand its applications

Jing-yu LIN, Ri-hui WU, Hong-man WANG, Ye-bin LIU

期刊论文

Determination of persistent organic pollutants by gas chromatography/laser multiphoton ionization/time-of-flight

Osamu SHITAMICHI, Taiki MATSUI, Yamei HUI, Weiwei CHEN, Totaro IMASAKA

期刊论文

Characterization of submicron aerosols in the urban outflow of the central Pearl River Delta region of China

Zhaoheng GONG, Zijuan LAN, Lian XUE, Liwu ZENG, Lingyan HE, Xiaofeng HUANG

期刊论文

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

期刊论文

Single particle analysis of ambient aerosols in Shanghai during the World Exposition, 2010: two case studies

Shikang TAO, Xinning WANG, Hong CHEN, Xin YANG, Mei LI, Lei LI, Zhen ZHOU

期刊论文

基于普通器件实现快1000倍的相机与机器视觉

Tiejun Huang, Yajing Zheng, Zhaofei Yu, Rui Chen, Yuan Li, Ruiqin Xiong, Lei Ma, Junwei Zhao, Siwei Dong, Lin Zhu, Jianing Li, Shanshan Jia, Yihua Fu, Boxin Shi, Si Wu, Yonghong Tian

期刊论文

适用于大视场红外地球敏感器的相机标定方法

邓华健1,2,王昊1,2,韩晓亚3,刘洋1,2,金仲和1,2

期刊论文

航空航天技术与力学

陈士橹

期刊论文

Response surface regression analysis on FeCrBSi particle in-flight properties by plasma spray

Runbo MA,Lihong DONG,Haidou WANG,Shuying CHEN,Zhiguo XING

期刊论文

β-粒子在穿越铜狭缝中的横向台阶分布

朱永强,郝建宇

期刊论文

Comparative proteomic analysis of cold responsive proteins in two wheat cultivars with different tolerance to spring radiation frost

Shujuan ZHANG,Guoqi SONG,Yulian LI,Jie GAO,Jiao WANG,Guiju CHEN,Haosheng LI,Genying LI,Zhendong ZHAO

期刊论文

多孔径光学成像系统及其光场采集数学模型

祁启明,傅瑞罡,邵铮铮,王平,范红旗

期刊论文

HY-2A卫星雷达高度计设计及其在轨工作结果

许可,刘和光,姜景山

期刊论文

基于张量因子分解框架的航班延误模式分析

张明远, 陈莘文, 孙立君, 杜文博, 曹先彬

期刊论文