High-speed Image Data Research Articles

Dynamic in situ measurement of axial segregation of E-CAT particles in a bubbling fluidized bed

The present paper summarizes comprehensive in situ measurements of the temporal segregation/mixing behavior of the non-spherical Geldart B and D E-CAT particles mixture in a bubbling fluidized bed. The experiments are performed for both unsieved and sieved E-CAT particles with varying particle size distribution width and at the fluidization velocity ranging from 1.3 to 5Umf. The high-speed pressure and image data were used to provide time-resolved quantification of dynamic expanded bed height and pressure drop during the experiment. In parallel, a hybrid machine learning-aided image processing algorithm has been developed for quantifying the instantaneous particle size distribution at varying axial locations. Results reveal that the segregation exists only at low fluidization velocities (1.3 and 1.6Umf) for unsieved cases with a wider size distribution. In contrast, particles with a narrower distribution exhibited well-mixed behavior for the full range of tested gas velocities. The segregation intensity and spatial extent were found to correlate with particle size distribution width and fluidization velocity, respectively. In addition, by analyzing pressure, expanded bed height, particle size and motion, and bubble characteristics, we provided a comprehensive multi-scale dynamic view of the segregation process. This in-depth understanding of the process, coupled with the time-resolved datasets obtained, can be instrumental for benchmarking numerical models in solid–gas multiphase flows and for optimizing the design of fluidized beds.

Characterizing the cracking process of various rock types under Brazilian loading based on coupled Acoustic Emission and high-speed imaging techniques

Tensile strength is one of the important mechanical properties of rock and rock-like materials and its accurate estimation and understanding of its failure mechanism are crucial for efficient design of structures on or within the rock masses. Amongst various approaches developed for estimating this property, Brazilian testing has received considerable attention analytically, numerically and experimentally. The test has been deployed for a wide range of materials such as rock, concrete, and ceramic, however its fracturing process at micro and macro scales has not yet been properly characterized. Thus, in this study, for a full understanding of the fracturing process of different rock types under indirect tensile loading, the coupled Acoustic Emission (AE) and high-speed imaging techniques were used to characterize the generated micro and macrocracks under Brazilian loading. The characteristics of AE parameters and the evolution of micro-macro cracks were investigated for three different rocks including sandstone, coal and granite at different sizes and loading configurations. A systematic framework was developed to exhibit the link between micro and macro fracturing processes under Brazilian loading. It was noted that the tensile microcracks are the first to initiate during the Brazilian failure with high intensity compared to shear microcracks. Transition in microcracking mechanism from tension to shear was evident in the samples with high brittleness. The tensile microcracks showed ascending trends with a decrease in geometrical or volumetric sample size for granite and sandstone, while its trend for coal was inconclusive due to its unique intrinsic fracture network or so-called “cleat network”. At macro scale level, single and multiple cracking mechanisms were observed in the tested samples where those with high shear microcracks mostly revealed failure under multiple cracking. Finally, some insights were provided into the transition from single tensile cracking to multiple tensile/shear cracking based on high-speed image data with high resolution.

A Novel Scheme of an Optimal Data Rate Transmission for Airborne Telemetry of Long Range Aerospace Vehicle

Airborne telemetry data is inevitable during the development phase of an aerospace vehicle. With the availability of telemetry data the vehicle characteristics are evaluated and the vehicle objectives are achieved subsequently. During the trajectory path, the airborne telemetry system transmits vehicle data continuously and ground receiving station receives it. The availability of data at ground station is solely dependent on various parameters; primarily data rate, modulation, RF power, etc. In this paper, typical data rate of telemetry for long range aerospace vehicle is analyzed and an innovative scheme is proposed for optimal data rate transmission with multi-resolution of high speed image data for distributed telemetry system. The scheme is implemented on 25 nm ZYNQ CSOC of telemetry hardware and synthesized netlist is simulated, performance is evaluated and results verified on telemetry hardware.

A Multiscale Aligned Video Super-Resolution Network for Improving Vibration Signal Measurement Accuracy

The quality of sequence frames is the premise of obtaining accurate vibration curves by visual vibration measurement method. Existing methods for video super-resolution reconstruction (VSR) have large models and slow inference speeds, which are not suitable for practical industrial applications. This paper proposes a video super-resolution network framework based on the pyramid and deformable convolution to measure the three key indicators of algorithm accuracy, speed, and model size. Specifically, we designed a pyramid alignment module (PAM) that includes a deformable self-attention module (DSA) to focus on the motion estimation of the region of interest while suppressing unrealistic motion estimation. In addition, the two-way propagation method combined with the PAM can be used to ensure that all frames in the input sequence can be balanced to enjoy the information of the full sequence of frames when aligned. The experimental results show that the proposed method improves the PSNR by 0.58dB compared with the existing reconstruction algorithm on the high-speed rotor image data set produced in this paper, and reduces the reasoning time by 41.5% and the model size by 9.1%. Finally, the rotor vibration displacement analysis experiment shows that the vibration signal obtained from the rotor data enhanced by this algorithm has better periodicity and stability. Our code will be available at https://github.com/candygogogogo/Rotor-Sequence-Image-Enhancement.

The development and evaluation of a fully automated markerless motion capture workflow

This study presented a fully automated deep learning based markerless motion capture workflow and evaluated its performance against marker-based motion capture during overground running, walking and counter movement jumping. Multi-view high speed (200 Hz) image data were collected concurrently with marker-based motion capture (criterion data), permitting a direct comparison between methods. Lower limb kinematic data for 15 participants were computed using 2D pose estimation, our 3D fusion process and OpenSim based inverse kinematics modelling. Results demonstrated high levels of agreement for lower limb joint angles, with mean differences ranging “0.1° − 10.5° for hip (3 DoF) joint rotations, and 0.7° − 3.9° for knee (1 DoF) and ankle (2 DoF) rotations. These differences generally fall within the documented uncertainties of marker-based motion capture, suggesting that our markerless approach could be used for appropriate biomechanics applications. We used an open-source, modular and customisable workflow, allowing for integration with other popular biomechanics tools such as OpenSim. By developing open-source tools, we hope to facilitate the democratisation of markerless motion capture technology and encourage the transparent development of markerless methods. This presents exciting opportunities for biomechanics researchers and practitioners to capture large amounts of high quality, ecologically valid data both in the laboratory and in the wild.

Nonlinear characteristics and corrections of near-field underwater explosion shock waves

The shock wave characteristics within the near-field are one of the most challenging aspects of understanding an underwater explosion. The latest numerical and experimental techniques were utilized to investigate the near-field pressure distribution and decay features after a shock disturbance. The governing equations in the numerical simulation were discretized with a fifth-order weighted essentially non-oscillatory scheme in space and a third-order Runge–Kutta scheme in time, and multi-medium interactions were defined and resolved via the modified ghost fluid method. The test system consisted of a synchronized high-speed framing camera and polyvinylidene fluoride (PVDF) sensors. Three identical spherical composition B charges were examined under the same test conditions, and the raw data from the high-speed camera were processed with edge detection and circle fitting techniques. The comparison showed that the high-speed camera image data, the PVDF signals, and the numerical computation results were highly consistent with each other. Higher-order correction terms were added to the pressure peak distribution model and the pressure decay model as nonlinear corrections based on further comprehensive and insightful analysis of the verified results. The corrected models not only fit with the near-field data but had better accuracy under the far-field condition as well.

Vortex formation in a strongly coupled dusty plasma flow past an obstacle

A pair of counter-rotating symmetric vortices has been observed in the wake behind a stationary obstacle (dust void) in a flowing dusty plasma. A strongly coupled dusty plasma flow with controllable velocity is generated and directed toward the void in a novel experiment. In the unsteady laminar flow regime, the curl of the fluid flow velocity along the boundary layer of the void generates the vortex pair behind the void. Particle image velocimetry analysis of high speed image data clearly depicts the flow pattern and the vorticities. The shear viscosity of the dusty plasma fluid along with the experimental parameters is considered to obtain the Reynolds number range for the evolution of the vortices. Molecular dynamics simulation is also performed to support the experimental observation.

Characterization of luminescent mini-tufts in quantitative flow visualization experiments: Surface flow analysis and modelization

As a widely used surface flow visualization method, luminescent mini-tuft has become one challenging topic with its practical advantages in quantitative flow measurement. The luminescent mini-tufts method is preferred with its reduced size and increased luminescence, which is suitable for surface visualization measurement. To provide a standard method/procedure in quantitative analysis for luminescent mini-tuft measurement, the current study established an experimental characterization platform of luminescent mini-tufts method and conducted flat-pate model for flow analysis. The experimental system is consisted of wind tunnel and model section, high-speed image data recording system, digital image processing as well as the control system. The digital imaging processing method for result analysis is also explained, which includes the dark current image extraction, averaging, mini-tufts recognition, and tuft inclination angle/tuft angle estimation process. In this study, the steady flow characterization and quantitative flow analysis is conducted on a flat plate model (Re = 1.6 × 105–6.6 × 105), which is combined with hot-wire anemometry to investigate the basic surface flow topology and boundary layer behaviors. The method is shown capable of capturing both the steady and transient behaviors of a surface flow. Luminescent mini-tufts physical model is also established and found good agreement with the experimental results in this study, which in turn support the mini-tufts characterization and selection in practical applications.

(Invited) Proximity Gettering Design of Hydrocarbon Molecular Ion Implanted Silicon Wafers Using Direct Bonding Technique for Advanced CMOS Image Sensors: A Review

Complementary metal oxide semiconductor (CMOS) image sensors have become widely used ubiquitous devices such as smart phone and personal computer type tablets. Consumer markets strongly demands more high sensitivity imaging and more high speed image data processing for achieving advanced CMOS image sensor fabrication. However, there are some serious improvement technical issues in CMOS image sensor fabrication process. Extremely important technical issue is metallic impurity contaminated device active region during device fabrication process such as high temperature rapid thermal annealing, dry etching and plasma heat treatment. Metallic impurities formed deep energy level defects in the silicon band-gap. Thus, these deep energy level defects strongly affects electrical device characteristic such as pn-junction leakage current, recombination lifetime and gate oxide breakdown voltage. Another technical issue is oxygen impurity out-diffused to the device active region from a Czochralski (CZ) grown silicon substrate during device heat process. Oxygen impurity formed oxygen related deep energy level defects in the device active region of photo-diode space charge region and transfer transistor gate channel region. These oxygen related defects strongly influenced on electrical device performance such as image lag. Therefore, in recent years, CMOS image sensor manufacturers have strongly demanded silicon wafers with the highest metal and oxygen impurities gettering capability during CMOS device processes. In response, we have developed a novel gettering wafer production concept using a hydrocarbon molecular ion implantation technique for advanced CMOS image sensors [1][2][3]. This technique can implant a silicon wafer surface simultaneously with carbon and hydrogen elements that form the projection range using a hydrocarbon compound molecular gas source. In our previous study, it was found that a hydrocarbon molecular ion implanted silicon wafer had three unique characteristics for high performance of advanced CMOS image sensors. First, a hydrocarbon molecular ion projection range has high gettering capability of metallic impurities [1][2][4]. Second, this projection range also has a diffusion barrier effect for oxygen impurities out-diffusing to the device active region from a CZ grown silicon wafer substrate [5]. Third, it is expected that diffusing hydrogen to the device active region from the hydrogen of hydrocarbon molecular ions gettered in the projection range during the device fabrication process will have a passivation effect on unreconstructed surface dangling bonds and Si/SiO2 interface state densities such as local oxidation of silicon or shallow trench isolation [6][7]. Moreover, we achieved more improvement for gettering capability of hydrocarbon molecular ion implanted silicon wafer which formed epitaxial layer without epitaxial growth process using room temperature direct bonding technique. In this presentation, we demonstrate that a hydrocarbon molecular ion implanted silicon wafers using room temperature direct bonding technique has high gettering capability characteristics for transition metal and light element impurities such as oxygen, and hydrogen during the CMOS image sensor fabrication process.

High-speed, high-frequency ultrasound, in utero vector-flow imaging of mouse embryos

Real-time imaging of the embryonic murine cardiovascular system is challenging due to the small size of the mouse embryo and rapid heart rate. High-frequency, linear-array ultrasound systems designed for small-animal imaging provide high-frame-rate and Doppler modes but are limited in regards to the field of view that can be imaged at fine-temporal and -spatial resolution. Here, a plane-wave imaging method was used to obtain high-speed image data from in utero mouse embryos and multi-angle, vector-flow algorithms were applied to the data to provide information on blood flow patterns in major organs. An 18-MHz linear array was used to acquire plane-wave data at absolute frame rates ≥10 kHz using a set of fixed transmission angles. After beamforming, vector-flow processing and image compounding, effective frame rates were on the order of 2 kHz. Data were acquired from the embryonic liver, heart and umbilical cord. Vector-flow results clearly revealed the complex nature of blood-flow patterns in the embryo with fine-temporal and -spatial resolution.

多路基于TLK2711高速串行图像数据的传输系统

多路基于TLK2711高速串行图像数据的传输系统

Development of an inspection system using an UV wavelength for defects on the thin electrode in a multilayer pattern

Generally, the Organic Light-Emitting Diode (OLED), Light-Emitting Diode (LCD), Touch Screen Panel (TSP) glass and Thin Film Transistor (TFT) pattern consists of multiple layers of electrodes separated by thin insulating films. In multilayered devices, when using visible light to inspect the electrode pattern and the defect, the critical shapes of a specific layer are difficult to define. To increase the image contrast between the materials and the layers, this study uses a UV wavelength, which has larger selective differences in reflectance than a visible wavelength. The newly-developed optical system and image analysis units are made to focus on a specific UV range to precisely define a top electrode layer. Two types of magnification systems are developed. Direct side illumination is available in a magnification 1.2 (1.2x) system with a large back focal length (BFL). However, in a magnification 3 (3x) system, on-axis line beam illumination is needed. A multi-point LED source (custom-made) and an anamorphic optical system is used to increase the light efficiency and decrease the noise. Electric units and an algorithm for high-speed image processing and data transfer are also developed. The final images have good selective contrast between the layers despite the high-depth condition decided by the required NA for the target resolution. This system can be used for the inspection of general display panels, Printed Circuit Board (PCB) patterns, and mobile glasses that are composed of multilayered films.

Piezoelectric Energy Harvesting from Wind Using Coupled Bending-Torsional Vibrations

Energy harvesting using Polyvinylidene-fluoride (PVDF) piezoelectric beams from fluid-induced flutter was studied. Vibration tests were performed to compare the power output of a piezoelectric beam subject to bending, and coupled bending-torsion loading conditions. A piezoelectric, harmonic computational analysis was done to further investigate the effect of the bending-torsion loading condition. It was evident that by inciting bending and torsion in the beam simultaneously, higher power outputs were achieved. However, when the tests were conducted in a wind tunnel with fluid forcing as opposed to steady-state vibration, the power output of the combined bending and torsion case was much lower than the bending-only case. High-speed image data indicated that the configurations subjected to bending-torsion flutter had lower bending deformations and were more prone to chaotic flapping, which inherently resulted in reduced power outputs. Finally, a vertical stalk configuration was examined, which produced five times more power compared to the horizontal stalk configuration at 8m/s wind speed due to excessive non-linear bending.

Design of a High-Speed Image Data Real-Time Storage and Display Circuit

The needs of large-capacity storage in high-speed image acquisition systems require the design of reliable and efficient storage instruments. The paper presents a FPGA-based high-speed storage instrument for high speed Camera Link image acquisition system. The FPGA processes the input data and stores the results into the storage array. Multi-chip large-capacity SLC NAND Flash chips constitute a storage array, with up to 100MByte/s storage rate, is used for the digitization image signals. A multilevel high-speed buffer structure based on abundant internal block RAM resources in FPGA is used for speeding up data access. At the same time, it can take advantage of FPGA constructing the corresponding VGA timing signals to control the video conversion chip ADV7123 to realize the function of real-time display. After a description of the proposed hardware and solutions, an experimental was built to test the performance. The results have shown that the FPGA-based acquisition system is a compact and flexible solution for high-speed image acquisition applications.

The Research and Design of Image Processing System Based on FPGA and DSP

In order to improve high performance and low power of image processing embedded system, A high-efficient image processing embedded system which is based on the field programmable gate array and high-speed digital signal processor in this paper. In the whole system, A novel data transmission structure with a dual-port RAM which is divided into two halves, is applied to buff the high-speed real-time image data by Ping-pong technique. Because all work in the system is divided between the FPGA and DSP in the form of the pipelined, it is 25% higher than the processing system based on the single DSP in performance.

Design and Implementation of High Speed Image Data Protocol Conversion System

This paper presented a high-speed image acquisition system based on PXI bus and Low Voltage Differential Signaling (LVDS) technology, with the characteristics of mass data, high-speed of data acquisition in the field of modem technology and scientific research. It expatiated the whole frame, and emphasized the design and implement of the system. It simulated the Ping-Pong operation of image data transmission, and tested the performance of the system. The results of test indicate that the high-speed image acquisition system has good ability of acquisition and transmission, and it can satisfy the engineering applied demand.

多路高速短消隐期线阵CCD图像数据存储设计

In order to solve the problem that the image data for the remote sensing aerospace camera is hard to store parallelly,which frequency is over 100 MHz,a multi-channel high-speed short blanking period CCD image data storage method is put forward.Firstly multi-channel image data are parallelly stored to SDRAM array,and then read out image data from SDRAM array and finally stored to computer's hard disk channel by channel via the frame grabber;for the problem of SDRAM fixed time refresh,the input image data's width is changed in order to reduce the SDRAM clock frequency;serial-parallel conversion and parallel-serial conversion operation combined with asynchronous FIFO are used as interface of diffe-rent clock domains,in order to solve the high speed image data non-integer times of the data width conversion,the formulas which are minimum depth of asynchronous FIFO and lowest operating frequency of the SDRAM are given.Research and application results show that the design based on FPGA as the data processing and controlling center meets the application requirements,the total parallelly writing data rate is up to 4.13 Gbit/s.

Design of High-Speed Remote Image Data Storage Memory Based on LVDS

Due to the characteristics of the large amount of data and the high rate of transmission in the system of remote image acquisition, introduces a remote image storage memory based on the LVDS. The FPGA design as the core, and adopting the LVDS interface solution string and the drive chip combined, ensure the effective of receiving remote data. Meanwhile the system adopted the flash programming technology of alternative two-plane to storage the image data. It realized the speed of 28.95 MB/s high-speed real-time image data storage requirements in system. The application shows that the data memory stable and reliable, meets the practical requirements

Fast attribute-based table clustering using Predicate-Trees: A vertical data mining approach

With technological advancements, massive amount of data is being collected in various domains. For instance, since the advent of digital image technology and remote sensing imagery RSI, NASA and U.S. Geological Survey through the Landsat Data Continuity Mission, has been capturing images of Earth down to 15 meters resolution. Likewise, consider the Internet, where, growth of social media, blog Web sites, etc. generates exponential amount of textual data on a daily basis. Since clustering of data is time-consuming, much of these data is archived even before proper analysis. In this paper, we propose two novel and extremely fast algorithms called imgFAUST or Fast Attribute-based Unsupervised and Supervised Table Clustering for images and a variation called docFAUST for textual data. Both these algorithms are based on Predicate-Trees which are compressed, lossless and data-mining-ready data structures. Without compromising much on the accuracy, our algorithms are fast and can be effectively used in high-speed image data and document analysis.

Design of Data Acquisition System Based on FPGA

A new kind of data acquisition system is introduced in this paper, in which the multi-channel synchronized real-time data acquisition under the coordinate control of field-programmable gate array(FPGA) is realized. The design uses field programmable gate arrays(FPGA) for the data processing and logic control. For high speed CCD image data processing, the paper adopts regional parallel processing based on FPGA. The FPGA inner block RAM is used to build high speed image data buffer is put into operation to achieve high speed image data integration and real-time processing. The proposed data acquisition system has characteristics of stable performance, flexible expansion, high real-timeness and integration