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关键词

小波变换 2

物元变换 2

CP）；符号间干扰（inter symbol interference， ISI）；载波间干扰（inter carrier interference 1

HHT 1

Hilbert变换 1

ICI）；最大似然估计（maximum likelihood estimation 1

MLE） 1

Mallat算法 1

Meyer小波变换 1

OFDM）；快速傅立叶变换（Fast Fourier transform， FFT）；循环前缀（cyclic prefix 1

Walsh循环谱 1

一氧化碳氧化 1

严格雪崩准则 1

中轴变换；包络；插值；蒙皮；圆 1

信号处理 1

傅立叶红外光谱 1

傅里叶变换 1

傅里叶变换红外成像 1

内积变换原理 1

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Transfer function solving, simulating and testing of thermal dynamics characteristics of a ballscrew

Junyong XIA, Bo WU, Youmin HU, Tielin SHI,

《机械工程前沿（英文）》 2010年第5卷第2期页码 233-241 doi: 10.1007/s11465-010-0014-0

摘要： Based on the theory of heat transfer, the transfer function between the thermal deformation of any point on the lead screw and the temperature of heat sources of a ballscrew under the influence of multi-changeable heat sources is solved by using the Laplace transform method. By solving the amplitude-frequency characteristics and phase-frequency characteristics of the transfer function, the steady-state response of thermal deformation of the ballscrew is obtained, and the thermal dynamics characteristics of the lead screw under the influence of multi-heat sources are further studied. Comparing with the result of finite-element simulation, the theoretical analyzing result accords with the steady-state part of the finite-element simulating result. Through tests of the steady-state response of thermal deformation, the thermal dynamics characteristics are further studied. The curves of tests by and large accord with the theoretical analyzing result, which shows that the method of transfer function is correct and valid in solving the steady-state response of thermal deformation.

关键词： ballscrew Laplace transform transfer function thermal dynamic characteristics

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Identification of faults through wavelet transform vis-à-vis fast Fourier transform of noisy vibration

null

《机械工程前沿（英文）》 2014年第9卷第2期页码 130-141 doi: 10.1007/s11465-014-0298-6

摘要：

Fault diagnosis of rolling element bearings requires efficient signal processing techniques. For this purpose, the performances of envelope detection with fast Fourier transform (FFT) and continuous wavelet transform (CWT) of vibration signals produced from a bearing with defects on inner race and rolling element, have been examined at low signal to noise ratio. Both simulated and experimental signals from identical bearings have been considered for the purpose of analysis. The bearings have been modeled as spring-mass-dashpot systems and the simulated signals have been obtained considering transfer functions for the bearing systems subjected to impulsive loads due to the defects. Frequency B spline wavelets have been applied for CWT and a discussion on wavelet selection has been presented for better effectiveness. Results show that use of CWT with the proposed wavelets overcomes the short coming of FFT while processing a noisy vibration signals for defect detection of bearings.

关键词： Fault detection spline wavelet continuous wavelet transform fast Fourier transform

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A reversibility-gain model for integer Karhunen-Loève transform design in video coding

Xing-guo ZHU,Lu YU

《信息与电子工程前沿（英文）》 2015年第16卷第10期页码 883-891 doi: 10.1631/FITEE.1500071

摘要： Karhunen-Loève transform (KLT) is the optimal transform that minimizes distortion at a given bit allocation for Gaussian source. As a KLT matrix usually contains non-integers, integer-KLT design is a classical problem. In this paper, a joint reversibility-gain (R-G) model is proposed for integer-KLT design in video coding. Specifically, the ‘reversibility’ is modeled according to distortion analysis in using forward and inverse integer transform without quantization. It not only measures how invertible a transform is, but also bounds the distortion introduced by the non-orthonormal integer transform process. The ‘gain’ means transform coding gain (TCG), which is a widely used criterion for transform design in video coding. Since KLT maximizes the TCG under some assumptions, here we define the TCG loss ratio (LR) to measure how much coding gain an integer-KLT loses when compared with the original KLT. Thus, the R-G model can be explained as follows: subject to a certain TCG LR, an integer-KLT with the best reversibility is the optimal integer transform for a given non-integer-KLT. Experimental results show that the R-G model can guide the design of integer-KLTs with good performance.

关键词： Integer transform Karhunen-Loè ve transform (KLT) Integer-KLT Transform coding Video coding

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基于位置旋转变换和非均匀快速傅立叶变换的机动目标高效相参检测 Research Articles

靳科1,赖涛2,齐艳丽3,黄洁1,赵拥军1

《信息与电子工程前沿（英文）》 2020年第21卷第8期页码 1251-1266 doi: 10.1631/FITEE.1900272

摘要：长时间相参积累能够显著提升雷达对机动目标的检测和运动参数估计性能。然而，相参积累期间目标的线性距离徙动、二次距离徙动和多普勒频率徙动将导致检测性能急剧下降。提出基于位置旋转变换和非均匀快速傅里叶变换的高效稳健相参积累方法。首先，利用二阶Keystone变换消除二次距离徙动。然后，利用旋转角度和多普勒频率之间的对应关系，构建相位补偿函数，从而利用位置旋转和非均匀快速傅里叶变换实现高效的参数估计。与现有代表性算法相比，所提算法能以较低运算复杂度实现近乎理想的检测性能。最后，基于雷达实测数据的实验证明所提算法有效。

关键词：相参积累；机动目标；参数估计；位置旋转变换；非均匀快速傅立叶变换

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Thermogravimetric coupled with Fourier transform infrared analysis study on thermal treatment of monopotassium

Yuheng FENG, Xuguang JIANG, Yong CHI, Xiaodong LI, Hongmei ZHU

《环境科学与工程前沿（英文）》 2011年第5卷第2期页码 186-192 doi: 10.1007/s11783-011-0322-6

摘要： In China, safe disposal of hazardous waste is more and more a necessity, urged by rapid economic development. The pyrolysis and combustion characteristics of a residue from producing monopotassium phosphate (monopotassium phosphate residue), considered as a hazardous waste, were studied using a thermogravimetric, coupled with Fourier transform infrared analyzer (TG-FTIR). Both pyrolysis and combustion runs can be subdivided into three stages: drying, thermal decomposition, and final devolatilization. The average weight loss rate during fast thermal decomposition stage in pyrolysis is higher than combustion. Acetic acid, methane, pentane, (acetyl) cyclopropane, 2,4,6-trichlorophenol, CO, and CO were distinguished in the pyrolysis process, while CO was the dominant combustion product.

关键词： hazardous waste combustion pyrolysis thermogravimetric coupled with Fourier transform infrared analysis (TG-FTIR) monopotassium phosphate residue

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稀疏快速Clifford傅里叶变换 Article

Rui WANG, Yi-xuan ZHOU, Yan-liang JIN, Wen-ming CAO

《信息与电子工程前沿（英文）》 2017年第18卷第8期页码 1131-1141 doi: 10.1631/FITEE.1500452

摘要： Clifford傅里叶变换（Clifford Fourier transform, CFT）可以应用于矢量场和标量场，但无法有效解决大数据问题，因为该算法是基于每个信号量计算的。稀疏快速傅里叶变换（sparse fast Fourier transform, sFFT）理论通过选择性地使用输入数据来处理大数据问题。

关键词：稀疏快速傅里叶变换（sFFT）；Clifford傅里叶变换（CFT）；稀疏快速Clifford傅里叶变换（SFCFT）；Clifford代数

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A new acoustic emission source location technique based on wavelet transform and mode analysis

JIAO Jing-pin, HE Cun-fu, WU Bin, FEI Ren-yuan, WANG Xiu-yan

《机械工程前沿（英文）》 2006年第1卷第3期页码 341-345 doi: 10.1007/s11465-006-0006-4

摘要： For wave propagation in dispersive media, the arrival time of the acoustic emission signal to the sensor is dependent on the setting of the threshold voltage, which results in the inaccuracy of the acoustic emission location. Based on the wavelet transform and the theory of modal acoustic emission, a new method is proposed to improve the accuracy of acoustic emission source location. It is believed that the acoustic emission signal propagation in the structure has the characteristics of multi-mode and dispersion, and the acoustic emission source location should use the arrival time to sensors obtained from the output signals not only at the same mode but also at the same frequency. The wavelet transform is used to resolve the problem. By utilizing the time-frequency data of the wavelet, the frequency-dependent arrival time traveling is easily obtained; by numerical computation of the wave s propagation in structure, the group velocity of the guided mode is also obtained, therefore the accuracy source location is realized. The acoustic emission source location experiments were conducted in a thin steel plate and results show that the technique is an effective tool for acoustic emission source location.

关键词： s propagation frequency emission signal signal propagation dispersive

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Non-stationary signal analysis based on general parameterized time--frequency transform and its application

Peng ZHOU, Zhike PENG, Shiqian CHEN, Yang YANG, Wenming ZHANG

《机械工程前沿（英文）》 2018年第13卷第2期页码 292-300 doi: 10.1007/s11465-017-0443-0

摘要：

With the development of large rotary machines for faster and more integrated performance, the condition monitoring and fault diagnosis for them are becoming more challenging. Since the time-frequency (TF) pattern of the vibration signal from the rotary machine often contains condition information and fault feature, the methods based on TF analysis have been widely-used to solve these two problems in the industrial community. This article introduces an effective non-stationary signal analysis method based on the general parameterized time–frequency transform (GPTFT). The GPTFT is achieved by inserting a rotation operator and a shift operator in the short-time Fourier transform. This method can produce a high-concentrated TF pattern with a general kernel. A multi-component instantaneous frequency (IF) extraction method is proposed based on it. The estimation for the IF of every component is accomplished by defining a spectrum concentration index (SCI). Moreover, such an IF estimation process is iteratively operated until all the components are extracted. The tests on three simulation examples and a real vibration signal demonstrate the effectiveness and superiority of our method.

关键词： rotary machines condition monitoring fault diagnosis GPTFT SCI

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Real time monitoring of bioreactor mAb IgG3 cell culture process dynamics via Fourier transform infrared

Huiquan Wu, Erik Read, Maury White, Brittany Chavez, Kurt Brorson, Cyrus Agarabi, Mansoor Khan

《化学科学与工程前沿（英文）》 2015年第9卷第3期页码 386-406 doi: 10.1007/s11705-015-1533-3

摘要： Compared to small molecule process analytical technology (PAT) applications, biotechnology product PAT applications have certain unique challenges and opportunities. Understanding process dynamics of bioreactor cell culture process is essential to establish an appropriate process control strategy for biotechnology product PAT applications. Inline spectroscopic techniques for real time monitoring of bioreactor cell culture process have the distinct potential to develop PAT approaches in manufacturing biotechnology drug products. However, the use of inline Fourier transform infrared (FTIR) spectroscopic techniques for bioreactor cell culture process monitoring has not been reported. In this work, real time inline FTIR Spectroscopy was applied to a lab scale bioreactor mAb IgG3 cell culture fluid biomolecular dynamic model. The technical feasibility of using FTIR Spectroscopy for real time tracking and monitoring four key cell culture metabolites (including glucose, glutamine, lactate, and ammonia) and protein yield at increasing levels of complexity (simple binary system, fully formulated media, actual bioreactor cell culture process) was evaluated via a stepwise approach. The FTIR fingerprints of the key metabolites were identified. The multivariate partial least squares (PLS) calibration models were established to correlate the process FTIR spectra with the concentrations of key metabolites and protein yield of in-process samples, either individually for each metabolite and protein or globally for all four metabolites simultaneously. Applying the 2 derivative pre-processing algorithm to the FTIR spectra helps to reduce the number of PLS latent variables needed significantly and thus simplify the interpretation of the PLS models. The validated PLS models show promise in predicting the concentration profiles of glucose, glutamine, lactate, and ammonia and protein yield over the course of the bioreactor cell culture process. Therefore, this work demonstrated the technical feasibility of real time monitoring of the bioreactor cell culture process via FTIR spectroscopy. Its implications for enabling cell culture PAT were discussed.

关键词： process analytical technology (PAT) Fourier-transform infrared (FTIR) spectroscopy partial least squares (PLS) regression mouse IgG3 bioreactor cell culture process real time process monitoring

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基于HHT的泄流结构损伤在线监测方法研究

练继建,李成业,刘昉,马斌

《中国工程科学》 2011年第13卷第12期页码 38-44

摘要：

结合HHT方法在描述信号瞬时特性和信号处理方面的独特优势，提出了一种基于HHT的泄流结构损伤实时监测诊断方法。首先，利用信号能量谱构造能量分布向量ηi，进而定义结构异常指标和预警指数，最后通过计算相邻时间段内的异常指标，实现结构损伤的在线监测。应用文中方法对一导墙结构进行数值仿真试验，结果表明，文章中定义的异常指标能够较准确地判断结构的损伤，同时具有一定的抗噪能力。

关键词：泄流结构 HHT 能量分布向量异常指标预警指数数值仿真

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Subspace transform induced robust similarity measure for facial images

Jian Zhang, Heng Zhang, Li-ling Bo, Hong-ran Li, Shuai Xu, Dong-qing Yuan,zhangjian@jou.edu.cn,zhangheng@jou.edu.cn

《信息与电子工程前沿（英文）》 2020年第21卷第9期页码 1267-1412 doi: 10.1631/FITEE.1900552

摘要： Similarity measure has long played a critical role and attracted great interest in various areas such as and machine perception. Nevertheless, there remains the issue of developing an efficient two-dimensional (2D) robust similarity measure method for images. Inspired by the properties of subspace, we develop an effective 2D technique, named transformation similarity measure (TSM), for robust . Specifically, the TSM method robustly determines the similarity between two well-aligned frontal facial images while weakening interference in the by linear transformation and singular value decomposition. We present the mathematical features and some odds to reveal the feasible and robust measure mechanism of TSM. The performance of the TSM method, combined with the nearest neighbor rule, is evaluated in under different challenges. Experimental results clearly show the advantages of the TSM method in terms of accuracy and robustness.

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可拓检测技术

余永权

《中国工程科学》 2001年第3卷第4期页码 88-94

摘要：

检测技术是目前多种学科的关键技术，检测中有两个难题：一个是无法检测的问题，另一个是检测精度提高的问题。基于可拓学矛盾转化的思想方法，提出了一种与传统检测技术不同的新技术--可拓检测，这种检测技术利用可拓学的物元概念及相关方法，从矛盾转化去研究检测技术，以解决无法检测的物理量检测问题。文章给出了可拓检测的有关概念，基本原理及结构，并且提出了有关的实施方法和应用实例。

关键词：可拓检测可拓学物元变换

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一种快速均匀的采用尺度不变特征变换描述符进行基于内容的卫星图像配准方法 Article

Hamed BOZORGI, Ali JAFARI

《信息与电子工程前沿（英文）》 2017年第18卷第8期页码 1108-1116 doi: 10.1631/FITEE.1500295

摘要：尺度不变特征变换（scale-invariant feature transform, SIFT）算法是一种成功应用于卫星图像配准的算法。本地SIFT描述符被许多研究者应用于改进图像检索流程。

关键词：基于内容的卫星图像配准；特征点分布；图像配准；线性判别准则；遥感；尺度不变特征变换

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Surface modification of cellulose nanocrystals

WANG Neng, DING Enyong, CHENG Rongshi

《化学科学与工程前沿（英文）》 2007年第1卷第3期页码 228-232 doi: 10.1007/s11705-007-0041-5

摘要： In order to improve the dispersibility of cellulose nanocrystal (CNC) particles, three different grafted reactions of acetylation, hydroxyethylation and hydroxypropylation were introduced to modify the CNC surface. The main advantages of these methods were the simple and easily controlled reaction conditions, and the dispersibility of the resulting products was distinctly improved. The properties of the modified CNC were characterized by means of Fourier transform infrared spectroscopy (FT-IR), C nuclear magnetic resonance (NMR), transmission electron microscopy (TEM) and thermogravimetric analyses (TGA). The results indicated that after desiccation, the modification products could be dispersed again in the proper solvents by ultrasonic treatments, and the diameter of their particles had no obvious changes. However, their thermal degradation behaviors were quite different. The initial decomposition temperature of the modified products via hydroxyethylation or hydroxypropylation was lower than that of modified products via acetylation.

关键词： acetylation degradation transform microscopy desiccation

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HHT-based crack identification method for start-up rotor

Bing LI, Chunlin ZHANG, Zhengjia HE

《机械工程前沿（英文）》 2012年第7卷第3期页码 300-304 doi: 10.1007/s11465-012-0328-1

摘要：

This paper presents a crack identification method for start-up rotor based on the Hilbert-Huang transform (HHT). With this method, the instantaneous frequency (IF) of each intrinsic mode function is obtained through the Hilbert transform, and the spectrum of IF is calculated accordingly. The influence of acceleration and crack depth on the rotor is analyzed through experiments. HHT is employed to detect the shallower crack, and is then tested during the start-up process of the rotor. The results of the experiment show that HHT is a better tool for crack detection than fast Fourier transform.

关键词： cracked rotor start-up Hilbert-Huang transform (HHT)