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Crack identification in concrete, using digital image correlation and neural network

《结构与土木工程前沿(英文)》 2024年 第18卷 第4期   页码 536-550 doi: 10.1007/s11709-024-1013-2

摘要: In engineering applications, concrete crack monitoring is very important. Traditional methods are of low efficiency, low accuracy, have poor timeliness, and are applicable in only a limited number of scenarios. Therefore, more comprehensive detection of concrete damage under different scenarios is of high value for practical engineering applications. Digital image correlation (DIC) technology can provide a large amount of experimental data, and neural network (NN) can process very rich data. Therefore, NN, including convolutional neural networks (CNN) and back propagation neural networks (BP), can be combined with DIC technology to analyze experimental data of three-point bending of plain concrete and four-point bending of reinforced concrete. In addition, strain parameters can be used for training, and displacement parameters can be added for comprehensive consideration. The data obtained by DIC technology are grouped for training, and the recognition results of NN show that the combination of strain and displacement parameters, i.e., the response of specimen surface and whole body, can make results more objective and comprehensive. The identification results obtained by CNN and BP show that these technologies can accurately identify cracks. The identification results for reinforced concrete specimens are less affected by noise than those of plain concrete specimens. CNN is more convenient because it can identify some features directly from images, recognizing the cracks formed by macro development. BP can issue early warning of the microscopic cracks, but it requires a large amount of data and computation. It can be seen that CNN is more intuitive and efficient in image processing, and is suitable when low accuracy is adequate, while BP is suitable for occasions with greater accuracy requirements. The two tools have advantages in different situations, and together they can play an important role in engineering monitoring.

关键词: digital image correlation     convolutional neural network     back propagation neural neural network     damage detection     concrete    

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    

Diagnosis method based on wavelet coefficient scale relativity correlation dimension for fault

GU Junjie, TIAN Jin, PENG Xuezhi

《能源前沿(英文)》 2008年 第2卷 第2期   页码 164-168 doi: 10.1007/s11708-008-0031-4

摘要: Correlation dimension as a tool to describe machinery condition is introduced. Vibration signals of the fan under different working conditions are analyzed using a threshold filtering algorithm based on the region relativity of the wavelet coefficients for reducing noise. The result shows that the characteristics of the signal could be preserved completely. The correlation dimension is able to identify conditions of the fan with faults compared with the normal condition, thereby providing an effective technology for condition monitoring and fault diagnosis of mechanical equipment.

关键词: effective technology     monitoring     mechanical equipment     relativity     Correlation    

Measurement and correlation of the solid-liquid equilibrium of 2-(

Yanhong SUN, Zhiyong LI, Chuang XIE, Wei CHEN, Cui ZHANG

《化学科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 110-115 doi: 10.1007/s11705-013-1316-7

摘要: In this work, the enthalpy of fusion and melting points of 2-( -butyl)-5-methylphenol (2B5MP) and 2-( -butyl)-4-methylphenol (2B4MP) were measured by differential scanning calorimetry (DSC). The binary solid-liquid equilibrium (SLE) of both compounds were predicted by integrated computer aided system (ICAS) and measured by DSC. The corresponding eutectic molar composition is 0.6998 and the eutectic temperature is 281.96 K. The quasi-static heat capacities of 2B5MP and 2B4MP were evaluated by stochastic temperature modulation DSC technique (TOPEM). The SLE experimental data were correlated using the Margules, Wilson, and non-random two liquid (NRTL) equations and a good agreement between measurement and calculation could be obtained.

关键词: solid-liquid equilibrium (SLE)     eutectic     integrated computer aided system (ICAS)     TOPEM     correlation    

Reliability analysis of urban gas transmission and distribution system based on FMEA and correlation

Su LI,Weiguo ZHOU

《能源前沿(英文)》 2014年 第8卷 第4期   页码 443-448 doi: 10.1007/s11708-014-0336-4

摘要: In order to improve the safety management of urban gas transmission and distribution system, failure mode and effects analysis (FMEA) was used to construct the reliability analysis system of the pipeline network. To solve the problem of subjectivity and uncertainty of the multi-expert decision making, the correlation operator was introduced into the calculation of the risk priority number (RPN). Using FMEA along with weight analysis and expert investigation approach, the FMEA evaluation table was given, including five failure modes, risk priority numbers, failure causes and effects, as well as corrective actions. The results show that correlation operator can directly process the linguistic terms and quantify the priority of the risks.

关键词: gas transmission and distribution system     risk evaluation     reliability analysis     failure mode and effects analysis (FMEA)     correlation operator    

Deformation field and crack analyses of concrete using digital image correlation method

Yijie HUANG, Xujia HE, Qing WANG, Jianzhuang XIAO

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1183-1199 doi: 10.1007/s11709-019-0545-3

摘要: The study on the deformation distribution and crack propagation of concrete under axial compression was conducted by the digital image correlation (DIC) method. The main parameter in this test is the water-cement ( / ) ratio. The novel analysis process and numerical program for DIC method were established. The displacements and strains of coarse aggregate, and cement mortar and interface transition zone (ITZ) were obtained and verified by experimental results. It was found that the axial displacement distributed non-uniformly during the loading stage, and the axial displacements of ITZs and cement mortar were larger than that of coarse aggregates before the occurrence of macro-cracks. The effect of / on the horizontal displacement was not obvious. Test results also showed that the transverse and shear deformation concentration areas (DCAs) were formed when stress reached 30%–40% of the peak stress. The transverse and shear DCAs crossed the cement mortar, and ITZs and coarse aggregates. However, the axial DCA mainly surrounded the coarse aggregate. Generally, the higher / was, the more size and number of DCAs were. The crack propagations of specimens varied with the variation of / . The micro-crack of concrete mainly initiated in the ITZs, irrespective of the / . The number and distribution range of cracks in concrete with high / were larger than those of cracks in specimen adopting low / . However, the value and width of cracks in high / specimen were relatively small. The / had an obvious effect on the characteristics of concrete deterioration. Finally, the characteristics of crack was also evaluated by comparing the calculated results.

关键词: deformation filed distribution     crack development     digital image correlation method     mechanical properties     water-cement ratio     characteristics of deformation and crack    

Free radical scavenging window of infertile patients with polycystic ovary syndrome: correlation with

null

《医学前沿(英文)》 2017年 第11卷 第2期   页码 247-252 doi: 10.1007/s11684-017-0519-6

摘要:

The activity of free radicals in follicular fluid was related to ovarian responsiveness, in vitro fertilization (IVF), and embryo transfer success rate. However, studies analyzing the relationship between the free radical scavenging capacity and embryo quality of infertile women with polycystic ovarian syndrome (PCOS) were lacking. The aim of this study was to evaluate the relationship between the free radical scavenging window of women with PCOS and their embryo quality. The free radical scavenging capacity of follicular fluid from women with PCOS was determined by a,a-diphenyl-b-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) assay, superoxide radical, and reactive oxygen species (ROS) assay. In the DPPH and ROS assays, the follicular fluid from grades I and II embryos was significantly higher than the follicular fluid from grades III and IV embryos. The lower control limit of DPPH radical scavenging capacity and upper control limit of ROS level were 13.2% and 109.0 cps, respectively. The calculated lower control limit and upper control limit were further confirmed in the follicular fluid of embryos of all grades. These cut-off values of free radical scavenging activity of follicular fluid could assist embryologists in choosing the development of embryos in PCOS patients undergoing IVF.

关键词: in vitro fertilization     PCOS     free radical     embryo quality    

Correlation analysis of couple optical paths for micro stereovision with stereo light microscope

WANG Yuezong, LI Desheng, YU Yaping

《机械工程前沿(英文)》 2007年 第2卷 第3期   页码 288-292 doi: 10.1007/s11465-007-0050-6

摘要: A micro stereovision system with a stereo light microscope (SLM) has been applied in micromanipulation systems. There is a coupling connection between two optical paths of a stereo light microscope. The coupling intension corresponds with two factors: the structure of an SLM and the position of an object point in the view of an SLM. In this paper, a correlation function is proposed to describe the coupling intension between the couple optical paths of an SLM. The quantified results are applied to the error analysis of the imaging model. Experiments show that the correlation of the optical paths of a common main objective of stereo light microscope (CMO-SLM) is little more than that of a G-SLM, and the error must be considered when a pinhole imaging model is used to analyze its correlation.

关键词: intension     micromanipulation     correlation function     objective     quantified    

Characteristic and correlation analysis of influent and energy consumption of wastewater treatment plants

Luxi Zou, Huaibo Li, Shuo Wang, Kaikai Zheng, Yan Wang, Guocheng Du, Ji Li

《环境科学与工程前沿(英文)》 2019年 第13卷 第6期 doi: 10.1007/s11783-019-1167-7

摘要: Poor biodegradability and insufficient carbon source are discovered from influent. Influent indices presented positively normal distribution or skewed distribution. Average energy consumption of WWTPs in Taihu Basin was as high as 0.458 kWh/m3. Energy consumption increases with the increase in influent volume and COD reduction. The total energy consumption decreases with the NH3-N reduction. The water quality and energy consumption of wastewater treatment plants (WWTPs) in Taihu Basin were evaluated on the basis of the operation data from 204 municipal WWTPs in the basin by using various statistical methods. The influent ammonia nitrogen (NH3-N) and total nitrogen (TN) of WWTPs in Taihu Basin showed normal distribution, whereas chemical oxygen demand (COD), biochemical oxygen demand (BOD5), suspended solid (SS), and total phosphorus (TP) showed positively skewed distribution. The influent BOD5/COD was 0.4%–0.6%, only 39.2% SS/BOD5 exceeded the standard by 36.3%, the average BOD5/TN was 3.82, and the probability of influent BOD5/TP>20 was 82.8%. The average energy consumption of WWTPs in Taihu Basin in 2017 was 0.458 kWh/m3. The specific energy consumption of WWTPs with a daily treatment capacity of more than 5 × 104 m3 in Taihu Basin was stable at 0.33 kWh/m3. A power function relationship was observed between the reduction in COD and NH3-N and the specific energy consumption of pollutant reduction, and the higher the pollutant reduction is, the lower the specific energy consumption of pollutant reduction presents. In addition, a linear relationship existed between the energy consumption of WWTPs and the specific energy consumption of influent volume and pollutant reduction. Therefore, upgrading and operation with less energy consumption of WWTPs is imperative and the suggestions for Taihu WWTPs based on stringent discharge standard are proposed in detail.

关键词: Taihu Basin     Wastewater treatment plant     Influent characteristics     Energy consumption evaluation     Specific energy consumption     SPSS correlation analysis    

与特定密码函数线性等价的布尔函数谱和自相关特征

杨锐,曾本胜,李世取

《中国工程科学》 2005年 第7卷 第11期   页码 60-65

摘要:

对线性等价意义下2个布尔函数的密码学性质的异同做了进一步的分析,得到了一个布尔函数线性等价于某个具有m阶相关免疫性的布尔函数的充分必要条件和线性等价于某个满足k次扩散准则的布尔函数的充分必要条件,在线性等价意义上,给出了由不具有相关免疫性且不满足扩散准则的布尔函数,构造既具有相关免疫性、也满足扩散准则的布尔函数的实例。

关键词: 线性等价     Walsh循环谱     自相关函数     相关免疫性     扩散准则     SAC    

A new heat transfer correlation for supercritical fluids

Yanhua YANG, Xu CHENG, Shanfang HUANG

《能源前沿(英文)》 2009年 第3卷 第2期   页码 226-232 doi: 10.1007/s11708-009-0022-0

摘要: A new method of heat transfer prediction in supercritical fluids is presented. Emphasis is put on the simplicity of the correlation structure and its explicit coupling with physical phenomena. Assessment of qualitative behaviour of heat transfer is conducted based on existing test data and experience gathered from open literature. Based on phenomenological analysis and test data evaluation, a single dimensionless number, the acceleration number, is introduced to correct the deviation of heat transfer from its conventional behaviour, which is predicted by the Dittus-Boelter equation. The new correlation structure excludes direct dependence of heat transfer coefficient on wall surface temperature and eliminates possible numerical convergence. The uncertainty analysis of test data provides information about the sources and the levels of uncertainties of various parameters and is highly required for the selection of both the dimensionless parameters implemented into the heat transfer correlation and the test data for the development and validation of new correlations. Comparison of various heat transfer correlations with the selected test data shows that the new correlation agrees better with the test data than other correlations selected from the open literature.

关键词: super critical fluids     heat transfer     circular tubes     prediction method    

Seismic ground motion analysis of Shanghai Pudong Airport site considering the effects of spatial correlation

JIANG Tong, CHEN Laiyun, XING Hailing, L? Xilin

《结构与土木工程前沿(英文)》 2007年 第1卷 第4期   页码 430-435 doi: 10.1007/s11709-007-0058-3

摘要: The terminal No. II of Shanghai Pudong International Airport is located at Pudong District of Shanghai City near shore of East China Sea, and the area of the long-span terminal is 400 m × 200 m. The construction site of the terminal locates on the irregular topography, and its alluvium achieves about 300 m in thickness. The spatial correlation of seismic ground motion, as well as the amplification of soft alluvium and the effect of irregular topography, should be considered. This paper uses a simplified method to obtain the response spectrum of the engineering bedrock under the irregular topography. The spectrum is used to generate the sets of spatially correlative horizontal and vertical seismic motions. The surface ground motion was calculated under incidence of the spatially correlative seismic motion by 2D finite element method (FEM) model considering nonlinear properties of the soil by means of the equivalent linear method. In order to compare the effect of 2D irregular topography, the seismic response analysis of 1D model is carried out by using the equivalent linear method. For indicating the effect of the spatial correlation of input motions, the horizontal uniform inputs, as well as the horizontal and vertical uniform input are carried out for the seismic response analysis of the site. Finally, some characteristics of seismic ground motion calculated for previously mentioned cases are compared.

关键词: surface ground     horizontal uniform     Finally     seismic ground     correlative seismic    

Correlation between carbon emissions and energy structure –Reliability analysis of low carbon target

Ben HUA

《能源前沿(英文)》 2011年 第5卷 第2期   页码 214-220 doi: 10.1007/s11708-010-0133-7

摘要: The influence of energy intensity on carbon intensity depends upon the fraction of energy mixes with high carbon emissions in the total energy mixes . The correlation of with a variety of primary energy mix fractions and technology advances such as CCS and CCHP is analyzed and deduced. Taking the long-term carbon reduction target in 2050 settled upon by the Copenhagen Agreement and the mid-term target suggested by the “450 Scenes Program” of the International Energy Agency (IEA) as constraints, the new pattern of the energy transition of the world in 2020, 2030, and 2050 are estimated and figured out. The peak value of energy consumption will lag behind the peak value of carbon emissions; the world energy structure shifting point will be in 2020–2025. Estimates show that China’s mid-2020 and long-term targets of energy-saving and emission reduction announced by the Chinese government might be achieved.

关键词: correlation     carbon emissions     energy consumption     high carbon emissions energy mix     target of emission reduction     reliability    

一种直观的一般秩相关系数 Research Articles

Divya PANDOVE, Shivani GOEL, Rinkle RANI

《信息与电子工程前沿(英文)》 2018年 第19卷 第6期   页码 699-711 doi: 10.1631/FITEE.1601549

摘要: 相关分析是研究数据模式和预测的有效机制。在看似无关的数据中建立相关性可得到许多有趣发现。提出一种算法,用于量化相关性理论并得出一个直观且更精确的相关系数。为计算配对值之间相关性,提出一项预测指标,称为一般秩相关系数。其满足预测指标的5个基本标准:样本规模的独立性、数值介于−1与1之间、测量单调性程度、对异常值不敏感性、直观演示。此外,使用实时数据集和随机数模拟实验对该指标进行验证。同时,展示了所提方程的数学推导过程,并与斯皮尔曼等级相关系数比较。结果表明,该指标在所有预测度量标准上均优于现存指标。

关键词: 一般秩相关系数;多变量分析;预测指标;斯皮尔曼等级相关系数    

Measurement and correlation of supercritical CO

Hiroshi MACHIDA, Ryosuke TAGUCHI, Yoshiyuki SATO, Louw J. FLOURUSSE, Cor J. PETERS, Richard L. SMITH

《化学科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 12-19 doi: 10.1007/s11705-009-0151-3

摘要: Ionicliquids combined with supercritical fluid technology hold great promise as working solvents for developing compact processes. Ionic liquids, which are organic molten salts, typically have extremely low volatility and high functionality, but possess high viscosities, surface tensions and low diffusion coefficients, which can limit their applicability. CO , on the other hand, especially in its supercritical state, is a green solvent that can be used advantageously when combined with the ionic liquid to provide viscosity and surface tension reduction and to promote mass transfer. The solubility of CO in the ionic liquid is key to estimating the important physical properties that include partition coefficients, viscosities, densities, interfacial tensions, thermal conductivities and heat capacities needed in contactor design. In this work, we examine a subset of available high pressure pure component ionic liquid PVT data and high pressure CO - ionic liquid solubility data and report new correlations for CO -ionic liquid systems with equations of state that have some industrial applications including: (1) general, (2) fuel desulfurization, (3) CO capture, and (4) chiral separation. New measurements of solubility data for the CO and 1-butyl-3-methylimidazolium octyl sulfate, [bmim][OcSO ] system are reported and correlated. In the correlation of the CO ionic liquid phase behavior, the Peng-Robinson and the Sanchez-Lacombe equations of state were considered and are compared. It is shown that excellent correlation of CO solubility can be obtained with either equation and they share some common characteristics regarding interaction parameters. In the Sanchez-Lacombe equation, parameters that are derived from the supercritical region were found to be important for obtaining good correlation of the CO -ionic liquid solubility data.

关键词: compact processes     chiral ionic liquids     separations     thermodynamic properties     equations of state    

标题 作者 时间 类型 操作

Crack identification in concrete, using digital image correlation and neural network

期刊论文

Digital image correlation-based structural state detection through deep learning

期刊论文

Diagnosis method based on wavelet coefficient scale relativity correlation dimension for fault

GU Junjie, TIAN Jin, PENG Xuezhi

期刊论文

Measurement and correlation of the solid-liquid equilibrium of 2-(

Yanhong SUN, Zhiyong LI, Chuang XIE, Wei CHEN, Cui ZHANG

期刊论文

Reliability analysis of urban gas transmission and distribution system based on FMEA and correlation

Su LI,Weiguo ZHOU

期刊论文

Deformation field and crack analyses of concrete using digital image correlation method

Yijie HUANG, Xujia HE, Qing WANG, Jianzhuang XIAO

期刊论文

Free radical scavenging window of infertile patients with polycystic ovary syndrome: correlation with

null

期刊论文

Correlation analysis of couple optical paths for micro stereovision with stereo light microscope

WANG Yuezong, LI Desheng, YU Yaping

期刊论文

Characteristic and correlation analysis of influent and energy consumption of wastewater treatment plants

Luxi Zou, Huaibo Li, Shuo Wang, Kaikai Zheng, Yan Wang, Guocheng Du, Ji Li

期刊论文

与特定密码函数线性等价的布尔函数谱和自相关特征

杨锐,曾本胜,李世取

期刊论文

A new heat transfer correlation for supercritical fluids

Yanhua YANG, Xu CHENG, Shanfang HUANG

期刊论文

Seismic ground motion analysis of Shanghai Pudong Airport site considering the effects of spatial correlation

JIANG Tong, CHEN Laiyun, XING Hailing, L? Xilin

期刊论文

Correlation between carbon emissions and energy structure –Reliability analysis of low carbon target

Ben HUA

期刊论文

一种直观的一般秩相关系数

Divya PANDOVE, Shivani GOEL, Rinkle RANI

期刊论文

Measurement and correlation of supercritical CO

Hiroshi MACHIDA, Ryosuke TAGUCHI, Yoshiyuki SATO, Louw J. FLOURUSSE, Cor J. PETERS, Richard L. SMITH

期刊论文