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彩色测温方法中物体辐射色域的界定和划分

王安全,程晓舫,陆少松

《中国工程科学》 2002年第4卷第8期页码 54-57

摘要：

介绍了彩色测温方法的基本原理，并基于可见光波段内光谱发射率的线性模型给出物体辐射颜色色品的表述；明确了一个色品最多只能求解出两个温度；解决了彩色测温方法中物体辐射色域的界定问题，并将辐射色域划分为温度单解域和双解域。

关键词：辐射测温彩色测温色域发射率

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我国海洋水色遥感应用工程技术的新进展

潘德炉,白雁

《中国工程科学》 2008年第10卷第9期页码 14-24

摘要：

介绍了近年来我国在海洋水色遥感应用工程技术方面的新进展，包括以应用为导向的关键技术研究和各类应用示范系统的开发等。针对当前海洋水色遥感业务化应用服务所面临的问题和一些急需解决的关键工程技术进行了分析和展望。

关键词：海洋水色遥感业务化应用中国海洋一号卫星

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Investigations on color variations of Morpho rhetenor butterfly wing scales

Guanglan LIAO, Haibo ZUO, Xuan JIANG, Xuefeng YANG, Tielin SHI

《机械工程前沿（英文）》 2012年第7卷第4期页码 394-400 doi: 10.1007/s11465-012-0347-y

摘要：

Experiments and simulations are carried out to investigate the optical properties of butterfly wing scales. The upper surface of a male butterfly wing presents a single-layer of scales, the microstructures of which are responsible for the brilliant blue color. The color varies from cyan blue to yellow green and soon afterwards returns back to cyan blue when some ethanol is dropped on the upper surface. At the start of the ethanol volatilization process, the reflection spectrum remains stable. As the ethanol further volatilizes, the peak reflectance decreases slightly, then increases dramatically. Meanwhile, the peak wavelength keeps approximately constant, then decreases, and keeps almost stable at the end of the process. Therefore, the optical properties depend strongly on the varying ambient conditions, including the refractive index and the thickness of the packing medium. Moreover, the possible causes for the scales in dark green region after several dropping ethanol experiments are clarified. This research benefits our understanding of the color variation mechanisms of the wing scales, and provides inspiration for further studies and applications.

关键词： Morpho rhetenor microstructures color variations ambient medium

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Multi-color space threshold segmentation and self-learning k-NN algorithm for surge test EUT status

Jian HUANG,Gui-xiong LIU

《机械工程前沿（英文）》 2016年第11卷第3期页码 311-315 doi: 10.1007/s11465-016-0376-z

摘要：

The identification of targets varies in different surge tests. A multi-color space threshold segmentation and self-learning k-nearest neighbor algorithm (k-NN) for equipment under test status identification was proposed after using feature matching to identify equipment status had to train new patterns every time before testing. First, color space (L*a*b*, hue saturation lightness (HSL), hue saturation value (HSV)) to segment was selected according to the high luminance points ratio and white luminance points ratio of the image. Second, the unknown class sample S_r was classified by the k-NN algorithm with training set T_z according to the feature vector, which was formed from number of pixels, eccentricity ratio, compactness ratio, and Euler’s numbers. Last, while the classification confidence coefficient equaled k, made S_r as one sample of pre-training set T_z′. The training set T_z increased to T_z₊₁ by T_z′ if T_z′ was saturated. In nine series of illuminant, indicator light, screen, and disturbances samples (a total of 21600 frames), the algorithm had a 98.65% identification accuracy, also selected five groups of samples to enlarge the training set from T₀ to T₅ by itself.

关键词： multi-color space k-nearest neighbor algorithm (k-NN) self-learning surge test

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高等植物叶片色域的理论研究

程晓舫,董金一,范学良,丁金磊

《中国工程科学》 2006年第8卷第12期页码 66-69

摘要：

利用叶绿素和类胡萝卜素的经典吸收光谱以及植物叶片中不含色素的其他物质成分的光谱，分别求得其在CIE1931色品图中的理论坐标，并根据色度学中的加法混色原理确定出高等植物叶色的理论域范围。实验数据与理论相吻合。

关键词：高等植物色素吸收光谱色度坐标色域

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固态照明系统中颜色维持率的研究进展 Review

Maryam Yazdan Mehr, Willem Dirk van Driel, 张国旗

《工程（英文）》 2015年第1卷第2期页码 170-178 doi: 10.15302/J-ENG-2015035

摘要：

本文全面回顾了固态照明 (SSL) 系统中颜色维持率 (也称颜色漂移) 的研究进展。首先介绍了颜色漂移及实际生产工艺中的颜色漂移实例，然后阐释了固态照明系统中不同部分的老化机制。通过对LED 产品中透镜/密封件所用的各种材料的介绍，探讨了这些材料对颜色漂移的促进作用。本文还就行业对光通维持率的定义标准化、表征描述与预测所做的工作进行了简单的回顾。

关键词： LED，颜色漂移，光通量衰减，流明衰减

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Anefficient quadrature demodulator for medical ultrasound imaging

Hao ZHOU,Yin-fei ZHENG

《信息与电子工程前沿（英文）》 2015年第16卷第4期页码 301-310 doi: 10.1631/FITEE.1400205

摘要： Quadrature demodulation is used in medical ultrasound imaging to derive the envelope and instantaneous phase of the received radio-frequency (RF) signal. In quadrature demodulation, RF signal is multiplied with the sine and cosine wave reference signal and then low-pass filtered to produce the base-band complex signal, which has high computational complexity. In this paper, we propose an efficient quadrature demodulation method for B-mode and color flow imaging, in which the RF signal is demodulated by a pair of finite impulse response filters without mixing with the reference signal, to reduce the computational complexity. The proposed method was evaluated with simulation and in vivo experiments. From the simulation results, the proposed quadrature demodulation method produced similar normalized residual sum of squares (NRSS) and velocity profile compared with the conventional quadrature demodulation method. In the in vivo color flow imaging experiments, the time of the demodulation process was 5.66 ms and 3.36 ms, for the conventional method and the proposed method, respectively. These results indicated that the proposed method can maintain the performance of quadrature demodulation while reducing computational complexity.

关键词： B-mode ultrasound imaging Color flow imaging Quadrature demodulation Finite impulse response filter

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Approximation of structural damping and input excitation force

Mohammad SALAVATI

《结构与土木工程前沿（英文）》 2017年第11卷第2期页码 244-254 doi: 10.1007/s11709-016-0371-9

摘要： Structural dynamic characteristics are the most significant parameters that play a decisive role in structural damage assessment. The more sensitive parameter to the damage is the damping behavior of the structure. The complexity of structural damping mechanisms has made this parameter to be one of the ongoing research topics. Despite all the difficulties in the modeling of damping, there are some approaches like as linear and nonlinear models which are described as the energy dissipation throughout viscous, material or structural hysteretic and frictional damping mechanisms. In the presence of a mathematical model of the damping mechanisms, it is possible to estimate the damping ratio from the theoretical comparison of the damped and un-damped systems. On the other hand, solving the inverse problem of the input force estimation and its distribution to each SDOFs, from the measured structural responses plays an important role in structural identification process. In this paper model-based damping approximation method and a model-less structural input estimation are considered. The effectiveness of proposed methods has been carried out through analytical and numerical simulation of the lumped mass system and the results are compared with reference data. Consequently, high convergence of the comparison results illustrates the satisfactory of proposed approximation methods.

关键词： structural modal parameters damping identification method input excitation force identification Inverse problem

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Effects of green roof damping and configuration on structural seismic response

《结构与土木工程前沿（英文）》页码 1133-1144 doi: 10.1007/s11709-023-0959-9

摘要： Sustainable structures are critical for addressing global climate change. Hence, their structural resilience or ability to recover from natural events must be considered comprehensively. Green roofs are a widely used sustainable feature that improve the environment while providing excellent occupant amenity. To expand their usage, their inherent damping and layout sensitivity to seismic performance are investigated in this study. The soil of a green roof can serve as a damper to dissipate the energy generated by earthquakes or other dynamic events. Results of preliminary analysis show that a green roof soil can increase localized damping by 2.5% under both dry and saturated conditions. Based on these findings, nonlinear time-history analyses are conducted on a three-story building in SAP2000 to monitor the structural behavior with and without a green roof. The increased damping in the green roof soil is beneficial to the structural performance, i.e., it reduces the building displacement and acceleration by 10% and 12%, respectively. Additionally, certain configurations are more effective and beneficial to the structural response than others, which suggests the possibility of design optimization. Based on the findings of this study, new methods of modeling and considering green roofs in structural design are established.

关键词： green infrastructure green roof structural resilience seismic design

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Development of an integrated structural health monitoring system for bridge structures in operational

Xinqun ZHU, Hong HAO

《结构与土木工程前沿（英文）》 2012年第6卷第3期页码 321-333 doi: 10.1007/s11709-012-0161-y

摘要： This paper presents an overview of development of an integrated structural health monitoring system. The integrated system includes vibration and guided-wave based structural health monitoring. It integrates the real-time heterogeneous sensor data acquiring system, data analysis and interpretation, physical-based numerical simulation of complex structural system under operational conditions and structural evaluation. The study is mainly focused on developing: integrated sensor technology, integrated structural damage identification with operational loads monitoring, and integrated structural evaluation with results from system identification. Numerical simulation and its implementation in laboratory show that the system is effective and reliable to detect local damage and global conditions of bridge structures.

关键词： integrated structural health monitoring operational conditions vibration and guided wave

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Combination of ARTP mutagenesis and color-mediated high-throughput screening to enhance 1-naphthol yield

Chenggang Qiu, Alei Zhang, Sha Tao, Kang Li, Kequan Chen, Pingkai Ouyang

《化学科学与工程前沿（英文）》 2020年第14卷第5期页码 793-801 doi: 10.1007/s11705-019-1876-2

摘要： Strain QCG of the aerobic bacteria is capable of producing 1-naphthol from naphthalene, this strain was first isolated and characterized in this study. Strain QCG was mutagenized to enhance 1-naphthol production, using atmospheric and room temperature plasma (ARTP) technology. Then, a microbial clone screening system was used to accelerate the operation. Meanwhile, a novel color-mediated high-throughput screening using 4-aminoantipyrine was performed to screen mutants. The optimal mutant strain QCG4 produced 19.58±0.34 mg∙L 1-naphthol from naphthalene that was 47.32% higher than that of the original strain (13.29±0.28 mg∙L ). In addition, the optimal conditions for 1-naphthol production via whole-cell catalysis of strain QCG4 were determined to be an OD of 40, 150 mg∙L naphthalene, and 7.5% dimethyl formamide as a co-solvent at pH 7.5 and 26°C for 3 h, resulting in 41.18±0.12 mg∙L 1-naphthol, i.e., the mutant strain produces a 2.1-fold higher yield compared to the original strain.

关键词： Bacillus cereus QCG naphthalene 1-naphthol ARTP mutagenesis high-throughput screening 4-aminoantipyrine

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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

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Identification of structural parameters and boundary conditions using a minimum number of measurement

Ali KARIMPOUR, Salam RAHMATALLA

《结构与土木工程前沿（英文）》 2020年第14卷第6期页码 1331-1348 doi: 10.1007/s11709-020-0686-4

摘要： This article proposes a novel methodology that uses mathematical and numerical models of a structure to build a data set and determine crucial nodes that possess the highest sensitivity. Regression surfaces between the structural parameters and structural output features, represented by the natural frequencies of the structure and local transmissibility, are built using the numerical data set. A description of a possible experimental application is provided, where sensors are mounted at crucial nodes, and the natural frequencies and local transmissibility at each natural frequency are determined from the power spectral density and the power spectral density ratios of the sensor responses, respectively. An inverse iterative process is then applied to identify the structural parameters by matching the experimental features with the available parameters in the myriad numerical data set. Three examples are presented to demonstrate the feasibility and efficacy of the proposed methodology. The results reveal that the method was able to accurately identify the boundary coefficients and physical parameters of the Euler-Bernoulli beam as well as a highway bridge model with elastic foundations using only two measurement points. It is expected that the proposed method will have practical applications in the identification and analysis of restored structural systems with unknown parameters and boundary coefficients.

关键词： structural model validation eigenvalue problem response surface inverse problems

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Advanced analysis for structural steel building design

CHEN Wai Fah

《结构与土木工程前沿（英文）》 2008年第2卷第3期页码 189-196 doi: 10.1007/s11709-008-0024-8

摘要： The 2005 AISC LRFD Specifications for Structural Steel Buildings are making it possible for designers to recognize explicitly the structural resistance provided within the elastic and inelastic ranges of behavior and up to the maximum load limit state. There is an increasing awareness of the need for practical second-order analysis approaches for a direct determination of overall structural system response. This paper attempts to present a simple, concise and reasonably comprehensive introduction to some of the theoretical and practical approaches which have been used in the traditional and modern processes of design of steel building structures.

关键词： building Specifications comprehensive introduction structural resistance traditional

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Estimation of optimum design of structural systems via machine learning

《结构与土木工程前沿（英文）》 2021年第15卷第6期页码 1441-1452 doi: 10.1007/s11709-021-0774-0

摘要： Three different structural engineering designs were investigated to determine optimum design variables, and then to estimate design parameters and the main objective function of designs directly, speedily, and effectively. Two different optimization operations were carried out: One used the harmony search (HS) algorithm, combining different ranges of both HS parameters and iteration with population numbers. The other used an estimation application that was done via artificial neural networks (ANN) to find out the estimated values of parameters. To explore the estimation success of ANN models, different test cases were proposed for the three structural designs. Outcomes of the study suggest that ANN estimation for structures is an effective, successful, and speedy tool to forecast and determine the real optimum results for any design model.

关键词： optimization metaheuristic algorithms harmony search structural designs machine learning artificial neural networks