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Edge detection of steel plates at high temperature using image measurement

Qiong Zhou, Qi An

《机械工程前沿(英文)》 2009年 第4卷 第1期   页码 77-82 doi: 10.1007/s11465-009-0013-1

摘要: An edge detection method for the measurement of steel plate’s thermal expansion is proposed in this paper, where the shrinkage of a steel plate is measured when temperature drops. First, images are picked up by an imaging system; a method of regional edge detection based on grayscales’ sudden change is then applied to detect the edges of the steel plate; finally, pixel coordinates of the edge position are transformed to physical coordinates through calibration parameters. The experiment shows that the real-time, high precision, and non-contact measurement of the steel plate’s edge position under high temperature can be realized using the imaging measurement method established in this paper.

关键词: thermal expansion     image measurement     edge detection     image calibration    

Development of a fan-stirred constant volume combustion chamber and turbulence measurement with PIV

《能源前沿(英文)》 2022年 第16卷 第6期   页码 973-987 doi: 10.1007/s11708-021-0762-z

摘要: A fan-stirred combustion chamber is deve-loped for spherically expanding flames, with P and T up to 10 bar and 473 K, respectively. Turbulence characteristics are estimated using particle image velocimetry (PIV) at different initial pressures (P = 0.5–5 bar), fan frequencies (ω = 0–2000 r/min), and impeller diameters (D = 100 and 114 mm). The flame propagation of methanol/air is investigated at different turbulence intensities (u′=0–1.77 m/s) and equivalence ratios (φ = 0.7–1.5). The results show that u′ is independent of P and proportional to ω, which can be up to 3.5 m/s at 2000 r/min. LT is independent of P and performs a power regression with ω approximately. The turbulent field is homogeneous and isotropic in the central region of the chamber while the inertial subrange of spatial energy spectrum is more collapsed to –5/3 law at a high ReT. Compared to laminar expanding flames, the morpho-logy of turbulent expanding flames is wrinkled and the wrinkles will be finer with the growth of turbulence intensity, consistent with the decline of the Taylor scale and the Kolmogorov scale. The determined SL in the present study is in good agreement with that of previous literature. The SL and ST of methanol/air have a non-monotonic trend with φ while peak ST is shifted to the richer side compared to SL. This indicates that the newly built turbulent combustion chamber is reliable for further experimental study.

关键词: fan-stirred combustion chamber     turbulence characteristics     particle image velocimetry (PIV)     methanol     turbulent expanding flames    

可视交互式图像聚类:一种机器视觉测量中目标无关的配置优化方法 Research Article

潘律翰,孙国道,常宝峰,夏旺,江棨,汤井威,梁荣华

《信息与电子工程前沿(英文)》 2023年 第24卷 第3期   页码 355-372 doi: 10.1631/FITEE.2200547

摘要: 机器视觉测量(machine vision measurement, MVM)是一种用于产品质量控制的重要方法,可有效、无损地测量目标面积或长度。

关键词: 机器视觉测量;打光方案设计;参数优化;可视交互式图像聚类    

density measurement for plastic injection molding via ultrasonic technology

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0714-2

摘要: Density variation during the injection molding process directly reflects the state of plastic melt and contains valuable information for process monitoring and optimization. Therefore, in-situ density measurement is of great interest and has significant application value. The existing methods, such as pressure−volume−temperature (PVT) method, have the shortages of time-delay and high cost of sensors. This study is the first to propose an in-situ density measurement method using ultrasonic technology. The analyses of the time-domain and frequency-domain signals are combined in the proposed method. The ultrasonic velocity is obtained from the time-domain signals, and the acoustic impedance is computed through a full-spectral analysis of the frequency-domain signals. Experiments with different process conditions are conducted, including different melt temperature, injection speed, material, and mold structure. Results show that the proposed method has good agreement with the PVT method. The proposed method has the advantages of in-situ measurement, non-destructive, high accuracy, low cost, and is of great application value for the injection molding industry.

关键词: ultrasonic measurement     melt density     in-situ measurement     injection molding    

Measurement of dynamic fracture toughness and failure behavior for explosive mock materials

Pengwan CHEN, Zhongbin ZHOU, Shaopeng MA, Qinwei MA, Fenglei HUANG

《机械工程前沿(英文)》 2011年 第6卷 第3期   页码 292-295 doi: 10.1007/s11465-011-0237-8

摘要:

In this work, a pre-cracked semi-circular shaped explosive simulant was loaded using a split Hopkinson pressure bar (SHPB). A high-speed camera was used to capture the deformation and fracture process of the specimen in situ. The digital images were processed using the digital image correlation (DIC) method. Next, full displacement and strain fields were obtained. The displacement vector field shows that the specimen fractured under tensile stress action. The strain field can be used to predict the crack propagation. Results show that the method of combined DIC and SHPB is effective to study the dynamic deformation and fracture behavior of explosive simulants. In addition, the specimen was loaded using a drop weight. The fracture toughness of the specimen was preliminary measured.

关键词: digital image correlation     polymer bonded explosive simulant     split Hopkinson pressure bar (SHPB)     semicircular bending test     deformation     fracture toughness    

Turbidity-adaptive underwater image enhancement method using image fusion

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-021-0669-8

摘要: Clear, correct imaging is a prerequisite for underwater operations. In real freshwater environment including rivers and lakes, the water bodies are usually turbid and dynamic, which brings extra troubles to quality of imaging due to color deviation and suspended particulate. Most of the existing underwater imaging methods focus on relatively clear underwater environment, it is uncertain that if those methods can work well in turbid and dynamic underwater environments. In this paper, we propose a turbidity-adaptive underwater image enhancement method. To deal with attenuation and scattering of varying degree, the turbidity is detected by the histogram of images. Based on the detection result, different image enhancement strategies are designed to deal with the problem of color deviation and blurring. The proposed method is verified by an underwater image dataset captured in real underwater environment. The result is evaluated by image metrics including structure similarity index measure, underwater color image quality evaluation metric, and speeded-up robust features. Test results exhibit that the method can correct the color deviation and improve the quality of underwater images.

关键词: turbidity     underwater image enhancement     image fusion     underwater robots     visibility    

Gradient-based compressive image fusion

Yang CHEN,Zheng QIN

《信息与电子工程前沿(英文)》 2015年 第16卷 第3期   页码 227-237 doi: 10.1631/FITEE.1400217

摘要: We present a novel image fusion scheme based on gradient and scrambled block Hadamard ensemble (SBHE) sampling for compressive sensing imaging. First, source images are compressed by compressive sensing, to facilitate the transmission of the sensor. In the fusion phase, the image gradient is calculated to reflect the abundance of its contour information. By compositing the gradient of each image, gradient-based weights are obtained, with which compressive sensing coefficients are achieved. Finally, inverse transformation is applied to the coefficients derived from fusion, and the fused image is obtained. Information entropy (IE), Xydeas’s and Piella’s metrics are applied as non-reference objective metrics to evaluate the fusion quality in line with different fusion schemes. In addition, different image fusion application scenarios are applied to explore the scenario adaptability of the proposed scheme. Simulation results demonstrate that the gradient-based scheme has the best performance, in terms of both subjective judgment and objective metrics. Furthermore, the gradient-based fusion scheme proposed in this paper can be applied in different fusion scenarios.

关键词: Compressive sensing (CS)     Image fusion     Gradient-based image fusion     CS-based image fusion    

新型400 km·h−1 级架空接触网监测技术

Chul Jin Cho, Young Park

《工程(英文)》 2016年 第2卷 第3期   页码 360-365 doi: 10.1016/J.ENG.2016.03.016

摘要:

近年来,高速铁路各项技术不断发展,列车运行速度从300 km•h–1 提高到400 km•h−1。本文介绍了由韩国研究者开发和论证的技术,即400 km•h−1 级集电性能评估方法。此外,本文还详细解释了基于视频图像的监测技术,其不需要直接接触供电系统的任何部件,这项技术被应用于检测以时速400 km 运行的高铁上架空接触网组件的稳定性。与常规使用激光传感器或者线相机(line camera)来监控架空接触网的系统不同,开发的新型系统通过视频数据来测量其处于活动状态的参数。根据在商业线路上实地测量的结果,这种系统能有效地测量架空接触网的各项参数。

关键词: 高速铁路     架空接触网     状态监测     基于图像处理的测量方式    

Deformable image registration with geometric changes

Yu LIU,Bo ZHU

《信息与电子工程前沿(英文)》 2015年 第16卷 第10期   页码 829-837 doi: 10.1631/FITEE.1500045

摘要: Geometric changes present a number of difficulties in deformable image registration. In this paper, we propose aglobal deformation framework to model geometric changes whilst promoting a smooth transformation between source and target images. To achieve this, we have developed an innovative model which significantly reduces the side effects of geometric changes in image registration, and thus improves the registration accuracy. Our key contribution is the introduction of a sparsity-inducing norm, which is typically L1 norm regularization targeting regions where geometric changes occur. This preserves the smoothness of global transformation by eliminating local transformation under different conditions. Numerical solutions are discussed and analyzed to guarantee the stability and fast convergence of our algorithm. To demonstrate the effectiveness and utility of this method, we evaluate it on both synthetic data and real data from traumatic brain injury (TBI). We show that the transformation estimated from our model is able to reconstruct the target image with lower instances of error than a standard elastic registration model.

关键词: Geometric changes     Image registration     Sparsity     Traumatic brain injury (TBI)    

A building unit decomposition model for energy leakage by infrared thermography image analysis

Yan SU, Fangjun HONG, Lianjie SHU

《能源前沿(英文)》 2020年 第14卷 第4期   页码 901-921 doi: 10.1007/s11708-020-0679-y

摘要: A quantitative energy leakage model was developed based on the thermography image data measured for both external and internal building surfaces. The infrared thermography images of both surfaces of doors, windows, and walls of an office building in the Hengqin Campus of University of Macao were taken at various times in a day for four seasons. The transient heat flux for sample units were obtained based on measurements of the seasonal transient local temperature differences and calculations of the effective thermal conductivity from the multiple-layer porous medium conduction model. Effects of construction unit types, orientations, and seasons were quantitatively investigated with unit transient orientation index factors. The corresponding electric energy consumption was calculated based on the air conditioning system coefficient of performance of heat pump and refrigerator cycles for different seasons. The model was validated by comparing to the electric meter records of energy consumption of the air conditioning system. The uncertainties of the predicted total building energy leakage are about 14.7%, 12.8%, 12.4%, and 15.8% for the four seasons, respectively. The differences between the predicted electric consumption and meter values are less than 13.4% and 5.4% for summer and winter, respectively. The typical daily thermal energy leakage value in winter is the highest among the four seasons. However, the daily electric energy consumption by the air conditioning system in summer and autumn is higher than that in winter. The present decomposition model for energy leakage is expected to provide a practical tool for quantitative analysis of energy leakage of buildings.

关键词: heat conductivity     heat coefficient     heat &fllig     ux     infrared thermography     thermal image    

Digital image correlation-based structural state detection through deep learning

《结构与土木工程前沿(英文)》 2022年 第16卷 第1期   页码 45-56 doi: 10.1007/s11709-021-0777-x

摘要: This paper presents a new approach for automatical classification of structural state through deep learning. In this work, a Convolutional Neural Network (CNN) was designed to fuse both the feature extraction and classification blocks into an intelligent and compact learning system and detect the structural state of a steel frame; the input was a series of vibration signals, and the output was a structural state. The digital image correlation (DIC) technology was utilized to collect vibration information of an actual steel frame, and subsequently, the raw signals, without further pre-processing, were directly utilized as the CNN samples. The results show that CNN can achieve 99% classification accuracy for the research model. Besides, compared with the backpropagation neural network (BPNN), the CNN had an accuracy similar to that of the BPNN, but it only consumes 19% of the training time. The outputs of the convolution and pooling layers were visually displayed and discussed as well. It is demonstrated that: 1) the CNN can extract the structural state information from the vibration signals and classify them; 2) the detection and computational performance of the CNN for the incomplete data are better than that of the BPNN; 3) the CNN has better anti-noise ability.

关键词: structural state detection     deep learning     digital image correlation     vibration signal     steel frame    

Three-dimensional reconstruction of light microscopy image sections: present and future

null

《医学前沿(英文)》 2015年 第9卷 第1期   页码 30-45 doi: 10.1007/s11684-014-0337-z

摘要:

Three-dimensional (3D) image reconstruction technologies can reveal previously hidden microstructures in human tissue. However, the lack of ideal, non-destructive cross-sectional imaging techniques is still a problem. Despite some drawbacks, histological sectioning remains one of the most powerful methods for accurate high-resolution representation of tissue structures. Computer technologies can produce 3D representations of interesting human tissue and organs that have been serial-sectioned, dyed or stained, imaged, and segmented for 3D visualization. 3D reconstruction also has great potential in the fields of tissue engineering and 3D printing. This article outlines the most common methods for 3D tissue section reconstruction. We describe the most important academic concepts in this field, and provide critical explanations and comparisons. We also note key steps in the reconstruction procedures, and highlight recent progress in the development of new reconstruction methods.

关键词: microtomy     3D imaging     computer-assisted image processing     3D printing     tissue scaffold    

A measurement system for thin elastohydrodynamic lubrication films

WANG Xuefeng, GUO Feng, YANG Peiran

《机械工程前沿(英文)》 2007年 第2卷 第2期   页码 193-196 doi: 10.1007/s11465-007-0032-8

摘要: An elastohydrodynamic lubrication (EHL) film measurement system using multi-beam interferometry is introduced in this paper. The measurement principle and the instrumentation are discussed. A simple and efficient method is suggested to obtain the fringe order of measured points. It is demonstrated that the presented measurement system can provide continuous measurement of lubricating films from nano to micro scales at a nano-level resolution, and can be used to investigate ultra-thin EHL films and tiny variations in EHL films.

关键词: instrumentation     continuous measurement     elastohydrodynamic lubrication     ultra-thin     measurement    

基于公钥具有双向影子图像验证功能且无像素扩张的图像秘密分享 Research Article

Xuehu Yan, Longlong Li, Jia Chen, Lei Sun

《信息与电子工程前沿(英文)》 2023年 第24卷 第1期   页码 88-103 doi: 10.1631/FITEE.2200118

摘要: 图像秘密分享(ISS)的研究越来越多,主要因为数字图像的重要性以及ISS可以广泛应用于云分布式存储和多方安全计算。影子图像认证日渐重要,通常包括影子图像真实性检测和识别。然而,传统处理者参与的方法主要是单向验证,即在解码阶段验证影子图像,存在像素扩张或额外辅助信息等不足。因此,分发(编码)阶段的影子图像认证对参与者来说也很重要。本文引入一种基于公钥的双向影子图像认证方法,实现(k, n)门限且无像素扩张。当处理者将每个影子图像分发给相应参与者时,参与者可以用其私钥验证接收到的影子图像。在解码阶段,处理者可以用其秘钥验证每个接收到的影子图像;此外,当获得任何k个或更多影子图像时,处理者可以无损解码秘密图像。理论分析、实验和比较验证了所提方法有效性。

关键词: 图像秘密分享;影子图像验证;公钥;像素扩张;无损恢复    

Experimental measurement of double-K fracture parameters of concrete with small-size aggregates

ZHANG Xiufang, XU Shilang, ZHENG Shuang

《结构与土木工程前沿(英文)》 2007年 第1卷 第4期   页码 448-457 doi: 10.1007/s11709-007-0061-8

摘要: The double- fracture model can well describe the development of cracks undergoing during the entire fracture process in concrete. Therefore, it has been selected as the theoretical basis of the Norm for fracture test of

关键词: development     concrete     theoretical     double- fracture    

标题 作者 时间 类型 操作

Edge detection of steel plates at high temperature using image measurement

Qiong Zhou, Qi An

期刊论文

Development of a fan-stirred constant volume combustion chamber and turbulence measurement with PIV

期刊论文

可视交互式图像聚类:一种机器视觉测量中目标无关的配置优化方法

潘律翰,孙国道,常宝峰,夏旺,江棨,汤井威,梁荣华

期刊论文

density measurement for plastic injection molding via ultrasonic technology

期刊论文

Measurement of dynamic fracture toughness and failure behavior for explosive mock materials

Pengwan CHEN, Zhongbin ZHOU, Shaopeng MA, Qinwei MA, Fenglei HUANG

期刊论文

Turbidity-adaptive underwater image enhancement method using image fusion

期刊论文

Gradient-based compressive image fusion

Yang CHEN,Zheng QIN

期刊论文

新型400 km·h−1 级架空接触网监测技术

Chul Jin Cho, Young Park

期刊论文

Deformable image registration with geometric changes

Yu LIU,Bo ZHU

期刊论文

A building unit decomposition model for energy leakage by infrared thermography image analysis

Yan SU, Fangjun HONG, Lianjie SHU

期刊论文

Digital image correlation-based structural state detection through deep learning

期刊论文

Three-dimensional reconstruction of light microscopy image sections: present and future

null

期刊论文

A measurement system for thin elastohydrodynamic lubrication films

WANG Xuefeng, GUO Feng, YANG Peiran

期刊论文

基于公钥具有双向影子图像验证功能且无像素扩张的图像秘密分享

Xuehu Yan, Longlong Li, Jia Chen, Lei Sun

期刊论文

Experimental measurement of double-K fracture parameters of concrete with small-size aggregates

ZHANG Xiufang, XU Shilang, ZHENG Shuang

期刊论文