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The quantum Kirchhoff equation and quantum current and energy spectrum of a homogeneous mesoscopic dissipation transmission line 被引量:2
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作者 崔元顺 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第10期3093-3096,共4页
On the basis of quantization of charge, the loop equations of quantum circuits are investigated by using the Helsenberg motion equation for a mesoscopic dissipation transmission line. On the supposition that the syste... On the basis of quantization of charge, the loop equations of quantum circuits are investigated by using the Helsenberg motion equation for a mesoscopic dissipation transmission line. On the supposition that the system has a symmetry under translation in charge space, the quantum current and the quantum energy spectrum in the mesoscopic transmission llne are given by solving their eigenvalue equations. Results show that the quantum current and the quantum energy spectrum are not only related to the parameters of the transmission llne, but also dependent on the quantized character of the charge obviously. 展开更多
关键词 mesoscopic dissipation transmission line quantum Kirchhoff's equation quantum current quantum energy spectrum
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Line spectrum detection algorithm based on the phase feature of target radiated noise 被引量:4
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作者 Enming Zheng Huabing Yu +1 位作者 Xinhua Chen Changyu Sun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第1期72-80,共9页
In order to improve the performance of line spectrum detection,according to the feature that the underwater target radiated noise containing stable line spectrum,the differences of the phase difference between line sp... In order to improve the performance of line spectrum detection,according to the feature that the underwater target radiated noise containing stable line spectrum,the differences of the phase difference between line spectrum and background noise,a weighted line spectrum detection algorithm based on the phase variance is proposed in frequency domain.After phase difference alignment,the phase variance of line spectrum and the phase of background noise,respectively,are small and big in frequency domain,this method utilizes the weighted statistical algorithm to cumulate the frequency spectrum based on the phase variance,which can restrain the background noise disturbance,and enhance the signal to noise ratio(SNR).The theory analysis and experimental results both verify that the proposed method can well enhance the energy of line spectrum,restrain the energy of background noise,and have better detection performance under lower SNR. 展开更多
关键词 information processing underwater target detection line spectrum detection phase variance.
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Line Spectrum Enhancement of Underwater Acoustic Signals Using Kalman Filter 被引量:1
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作者 Jiao Zhang Yaan Li +1 位作者 Wasiq Ali Lian Liu 《Journal of Marine Science and Application》 CSCD 2020年第1期148-154,共7页
To detect weak underwater acoustic signals radiated by submarines and other underwater equipment,an effective line spectrum enhancement algorithm based on Kalman filter and FFT processing is proposed.The proposed algo... To detect weak underwater acoustic signals radiated by submarines and other underwater equipment,an effective line spectrum enhancement algorithm based on Kalman filter and FFT processing is proposed.The proposed algorithm first determines the frequency components of the weak underwater signal and then filters the signal to enhance the line spectrum,thereby improving the signal-to-noise ratio(SNR).This paper discussed two cases:one is a simulated signal consisting of a dual-frequency sinusoidal periodic signal and Gaussian white noise,and the signal is received after passing through a Rayleigh fading channel;the other is a ship signal recorded from the South China Sea.The results show that the line spectrum of the underwater acoustic signal could be effectively enhanced in both cases,and the filtered waveform is smoother.The analysis of simulated signals and ship signal reflects the effectiveness of the proposed algorithm. 展开更多
关键词 line spectrum enhancement Kalman filter Signal detection Underwater acoustic signal Frequency estimation
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Research on Narrowband Line Spectrum Noise Control Method Based on Nearest Neighbor Filter and BP Neural Network Feedback Mechanism 被引量:1
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作者 Shuiping Zhang Xi Liang +2 位作者 Lin Shi Lei Yan Jun Tang 《Sound & Vibration》 EI 2023年第1期29-44,共16页
Thefilter-x least mean square(FxLMS)algorithm is widely used in active noise control(ANC)systems.However,because the algorithm is a feedback control algorithm based on the minimization of the error signal variance to ... Thefilter-x least mean square(FxLMS)algorithm is widely used in active noise control(ANC)systems.However,because the algorithm is a feedback control algorithm based on the minimization of the error signal variance to update thefilter coefficients,it has a certain delay,usually has a slow convergence speed,and the system response time is long and easily affected by the learning rate leading to the lack of system stability,which often fails to achieve the desired control effect in practice.In this paper,we propose an active control algorithm with near-est-neighbor trap structure and neural network feedback mechanism to reduce the coefficient update time of the FxLMS algorithm and use the neural network feedback mechanism to realize the parameter update,which is called NNR-BPFxLMS algorithm.In the paper,the schematic diagram of the feedback control is given,and the performance of the algorithm is analyzed.Under various noise conditions,it is shown by simulation and experiment that the NNR-BPFxLMS algorithm has the following three advantages:in terms of performance,it has higher noise reduction under the same number of sampling points,i.e.,it has faster convergence speed,and by computer simulation and sound pipe experiment,for simple ideal line spectrum noise,compared with the convergence speed of NNR-BPFxLMS is improved by more than 95%compared with FxLMS algorithm,and the convergence speed of real noise is also improved by more than 70%.In terms of stability,NNR-BPFxLMS is insensitive to step size changes.In terms of tracking performance,its algorithm responds quickly to sudden changes in the noise spectrum and can cope with the complex control requirements of sudden changes in the noise spectrum. 展开更多
关键词 FxLMS NNR-BPFxLMS line spectrum noise BP neural network feedback convergence speed
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A method of line spectrum extraction based on target radiated spectrum feature and its post-processing 被引量:1
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作者 DAI Wenshu ZHENG Enming BAO Kaikai 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第6期1381-1393,共13页
To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum... To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous spectrum.This method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval simultaneously.Statistical efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line spectrum.The change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical LSR.As the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically analyzed.The simulation detection gain demonstrates a good match with the theoretical model.The application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao Lake.In fact,combining the two methods for target detection reduces the missed detection rate.The proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect. 展开更多
关键词 towed linear array sonar target radiated noise spectrum line spectra level ratio(LSR) receiver operating characteristic(ROC)curve POST-PROCESSING
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Dynamic Promotional Resource Allocation for Segment Specific and Spectrum Effect of Promotion for a Product Line Incorporating Repeat Purchase Behavior 被引量:1
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作者 Prakash Chandra Jha Prerna Manik Anshu Gupta 《American Journal of Operations Research》 2013年第3期350-362,共13页
Promotion is an essential element in the marketing mix. It is used by businesses to inform, influence and persuade customers to adopt the products and services they offer. Without promotion, business would be stagnant... Promotion is an essential element in the marketing mix. It is used by businesses to inform, influence and persuade customers to adopt the products and services they offer. Without promotion, business would be stagnant and lack substantial growth because the brands would have low visibility in the market. Moreover, today’s vast and assorted markets comprise of customers with different needs and varied behavior. So it is rarely possible for companies to satisfy all customers by treating them alike. Thus there arises a need to divide the market into segments having customers with similar traits/characteristics. After identifying appropriate market segments, firms can design differentiated promotional campaigns for each segment. At the same time there can be a mass market promotional campaign that reaches different segments with a fixed spectrum. Also since promotional effort resources are limited, one must use them judiciously. In this paper, we formulate mathematical programming problem under repeat purchase scenario, which optimally allocates mass promotional effort resources and differentiated promotional effort resources across the segments dynamically in order to maximize the overall sales obtained from multiple products of a product line under budgetary and minimum sales aspiration level constraint on each product under consideration in each segment. The planning horizon is divided into multi periods, the adoption pattern of each product in each segment is observed in every subinterval and accordingly promotional effort allocations are determined for the next period till we reach the end of planning period. The optimization model has been further extended to incorporate minimum aspiration level constraints on total sales for each product under consideration from all the segments taken together. The non linear programming problem so formulated is solved using differential evolution approach. A numerical example has been discussed to illustrate applicability of the model. 展开更多
关键词 MARKET Segmentation DIFFERENTIATED MARKET PROMOTION Mass MARKET PROMOTION spectrum EFFECT Promotional Effort Allocation REPEAT Purchase Product line Non linear Programming Problem Differential Evolution
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Statistics Modeling of Shallow Sea Ambient Noise and Its Applications in Low-frequency Line Spectrum Detection
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作者 杨秀庭 赵晓哲 李刚 《Defence Technology(防务技术)》 SCIE EI CAS 2011年第2期78-81,共4页
The noise's statistical characteristics are very important for signal detection.In this paper,the ambient noise statistical characteristics are investigated by using the recorded noise data in sea trials first,and... The noise's statistical characteristics are very important for signal detection.In this paper,the ambient noise statistical characteristics are investigated by using the recorded noise data in sea trials first,and the results show that the generalized Gaussian distribution is a suitable model for the ambient noise modeling.Thereafter,the optimal detector based on maximum likelihood ratio can be deduced,and the asymptotic detector is also derived under weak signal assumption.The detector's performance is verified by using numerical simulation,and the results showthat the optimal and asymptotic detectors outperform the conventional correlation-integration system due to accuracy modeling of ambient noise. 展开更多
关键词 information processing technique generalized Gaussian distribution line spectrum detection ambient noise
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Special algorithm of enhancing underwater targetradiated dynamic line spectrum
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作者 Guo Yecai Zhao Junwei Chen Huawei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第4期797-801,共5页
Performance of traditional adaptive line enhancer (ALE) in suppressing Gaussian noise is low and can get worse at low input signal-to-noise ratio(SNR). For greatly overcoming these disadvantages, feature of fourth... Performance of traditional adaptive line enhancer (ALE) in suppressing Gaussian noise is low and can get worse at low input signal-to-noise ratio(SNR). For greatly overcoming these disadvantages, feature of fourth-order cumulant (FOC) different slices for quasi-stationary random process is analyzed, fourth order cumulant(FOC) different slice-based adaptive dynamic line enhancer is presented, and output SNR of the proposed enhancer is derived and bigger than that of the ALE via theoretical analysis. Simulation tests with the underwater moving target-radiated data have shown that the proposed enhancer outperforms the ALE in suppressing Gaussian noise and enhancing dynamic line spectrum feature. 展开更多
关键词 higher-order cumulant different slice dynamic line spectrum underwater moving target Gaussian noise.
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Saturated absorption spectrum of cesium micrometric-thin cell with suppressed crossover spectral lines
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作者 韩俊龙 王博闻 +5 位作者 郑俊鹤 陈书源 肖伟 吴腾 郭弘 彭翔 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期353-360,共8页
Micrometric-thin cells(MCs)with alkali vapor atoms have been valuable for research and applications of hyperfine Zeeman splitting and atomic magnetometers under strong magnetic fields.We theoretically and experimental... Micrometric-thin cells(MCs)with alkali vapor atoms have been valuable for research and applications of hyperfine Zeeman splitting and atomic magnetometers under strong magnetic fields.We theoretically and experimentally study the saturated absorption spectra using a 100-μm cesium MC,where the pump and probe beams are linearly polarized with mutually perpendicular polarizations,and the magnetic field is along the pump beam.Because of the distinctive thin chamber of the MC,crossover spectral lines in saturated absorption spectra are largely suppressed leading to clear splittings of hyperfine Zeeman transitions in experiments,and the effect of spatial magnetic field gradient is expected to be reduced.A calculation method is proposed to achieve good agreements between theoretical calculations and experimental results.This method successfully explains the suppression of crossover lines in MCs,as well as the effects of magnetic field direction,propagation and polarization directions of the pump/probe beam on saturated absorption spectrum.The saturated absorption spectrum with suppressed crossover lines is used for laser frequency stabilization,which may provide the potential value of MCs for high spatial resolution strong-field magnetometry with high sensitivity. 展开更多
关键词 micrometric-thin cells saturated absorption spectrum hyperfine Zeeman splitting crossover spectral lines laser frequency stabilization
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FFT Nuttall 窗四谱线插值修正谐波检测算法
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作者 邓慧慧 杨松霖 +2 位作者 杨学良 洪应平 徐贺杨 《测试技术学报》 2025年第1期96-103,共8页
利用传统傅里叶变换进行谐波信号分析时,由于很难严格做到同步采样,整周期截断,从而不可避免地产生频谱泄露与栏栅效应,降低了检测结果的精确性。为了提高检测结果精确度,在FFT(Fast Fourier Transformation)的基础上,对Hann窗、Blackma... 利用传统傅里叶变换进行谐波信号分析时,由于很难严格做到同步采样,整周期截断,从而不可避免地产生频谱泄露与栏栅效应,降低了检测结果的精确性。为了提高检测结果精确度,在FFT(Fast Fourier Transformation)的基础上,对Hann窗、Blackman窗、Blackmanharris窗、Nuttall窗的四谱线插值算法进行了研究,通过多项式拟合推导出不同余旋窗四线插值对应的幅值、频率、相位的修正公式。并在Matlab上对不同余旋窗四线插值算法进行仿真实验,与对应余旋窗的三谱线插值算法进行对比分析,结果表明四项三阶Nuttall窗的四谱线插值算法幅值精确度可达到10^(-5)~10^(-9)数量级,频率精确度可达到10^(-8)~10^(-9)数量级,相位精确度可达到10^(-3)~10^(-7)数量级,与其它算法相比精确度更高,旁瓣性能更好,能更好地抑制频谱泄露与栏栅效应。 展开更多
关键词 频谱泄露 栏栅效应 窗函数 三线谱插值 四线谱插值
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Time-frequency response spectrum of rotational ground motion and its application 被引量:16
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作者 Wei Che Qifeng Luo 《Earthquake Science》 CSCD 2010年第1期71-77,共7页
The rotational seismic motions are estimated from one station records of the 1999 Jiji (Chi-Chi), Taiwan, earthquake based on the theory of elastic plane wave propagation. The time-frequency response spectrum (TFRS... The rotational seismic motions are estimated from one station records of the 1999 Jiji (Chi-Chi), Taiwan, earthquake based on the theory of elastic plane wave propagation. The time-frequency response spectrum (TFRS) of the rotational motions is calculated and its characteristics are analyzed, then the TFRS is applied to analyze the damage mechanism of one twelve-storey frame concrete structure. The results show that one of the ground motion components can not reflect the characteristics of the seismic motions completely; the characteristics of each component, especially rotational motions, need to be studied. The damage line of the structure and TFRS of ground motion are important for seismic design, only the TFRS of input seismic wave is suitable, the structure design is reliable. 展开更多
关键词 Jiji (Chi-Chi) earthquake ground motion rotational component time-frequency response spectrum damage line
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Design and validation of real-time dynamic spectrum management in OFDM-based HNPLC systems 被引量:2
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作者 刘雯静 Guo Jingbo +1 位作者 Yan Yanxin Zhang Tongfei 《High Technology Letters》 EI CAS 2015年第4期379-387,共9页
Time-varying frequency selective attenuation and colored noises are unfavorable characteristics of power line communication(PLC) channels of the low voltage networks.To overcome these disadvantages,a novel real-time d... Time-varying frequency selective attenuation and colored noises are unfavorable characteristics of power line communication(PLC) channels of the low voltage networks.To overcome these disadvantages,a novel real-time dynamic spectrum management(DSM) algorithm in orthogonal frequency division multiplexing(OFDM)-based high-speed narrow-band power line communication(HNPLC) systems is proposed,and the corresponding FPGA circuit is designed and realized.Performance of the proposed DSM is validated with a large amount of network experiments under practical PLC circumstance.As the noise in each narrow subcarrier is approximately Gaussian,the proposed DSM adopts the BER/SER expression formulized via the AWGN channel to provide a handy and universal strategy for power allocation.The real-time requirement is guaranteed by choosing subcarriers in group and employing the same modulation scheme within each transmission.These measures are suitable for any modulation scheme no matter the system criterion is to maximize data rate or minimize power/BER.Algorithm design and hardware implementation of the proposed DSM are given with some flexible and efficient conversions.The DSM circuit is carried out with Xilinx KC705.Simulation and practical experiments validate that the proposed real-time DSM significantly improves system performance. 展开更多
关键词 real-time dynamic spectrum management high-speed narrowband power line com-munication (HNPLC) subcarrier grouping rate adaptive MULTI-CARRIER
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Deltaic Sandstone Pinch-out Lines Recongnition Based on Seismic Matching Pursuit Instantaneous Spectral Characteristics 被引量:2
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作者 Zhang Fanchang Li Chuanhui Yin Xingyao 《石油地球物理勘探》 EI CSCD 北大核心 2012年第A02期74-81,共8页
关键词 石油 地球物理勘探 地质调查 油气资源
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Methods for the Determination of Stable Isotopes of Carbon and Nitrogen Directly in Valine, Proline, Glutamine, and Glutamic Acid
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作者 Lamzira Farulava Levani Eliashvili +1 位作者 Vakhtang Betlemidze Bachana Sulava 《American Journal of Analytical Chemistry》 2023年第10期467-480,共14页
Amino acids are very important compounds for the body and are involved in important functions that keep us healthy. Amino acids are essential components such as valine, proline, glutamine and glutamic acid. They can b... Amino acids are very important compounds for the body and are involved in important functions that keep us healthy. Amino acids are essential components such as valine, proline, glutamine and glutamic acid. They can be synthesized either naturally or artificially. To examine the metabolism and regulate the synthesis process, compounds labeled with nitrogen or carbon isotopes need to be used. These isotopic compounds allow for more extensive research and enable studies that would otherwise be impossible. However, their use is dependent on the availability of simple, efficient methods for isotopic analysis. Currently, the determination of the atomic fraction of carbon and nitrogen isotopes is only possible through their conversion into molecular nitrogen or carbon monoxide or carbon dioxide. This leads to the loss of information about isotopic enrichment in specific centers of the molecule. This article explores a new direct approach to determining the atomic fraction of carbon and nitrogen isotopes in the isotope-modified or identical centers of these compounds. This method eliminates the transfer process and dilution due to nitrogen and carbon impurities. It is now possible to simultaneously determine the atomic fraction of nitrogen and carbon isotopes in the research substance. This method can be applied to amino acids, making it an effective tool for proposing new research methods. Several articles [1] [2] [3] have proposed similar methods for organic compounds and amino acids. 展开更多
关键词 VAline PROline GLUTAMINE Glutamic Acid Mass Spectrometer Mass spectrum Ion Current INTENSITY Mass lines Molecular and Fragment Ions
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The intensity calculation of the gas absorption line by multi-line Voigt fitting
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作者 周孟然 李振璧 +1 位作者 钟鸣宇 何刚 《Journal of Coal Science & Engineering(China)》 2008年第4期534-537,共4页
Adopted the distribution feedback type (DFB) laser to measure the coal mine gas methane, according to the methane located 1.6 μm nearby 2v3 with a R9 direct absorption spectrum, attraction wire intensity of each li... Adopted the distribution feedback type (DFB) laser to measure the coal mine gas methane, according to the methane located 1.6 μm nearby 2v3 with a R9 direct absorption spectrum, attraction wire intensity of each line was calculated through the multi-line Voigt fitting. The experimental result indicates that in the obtained four attraction recover of wire, the maximum deviation is 2.7%, and the minimum deviation is 0.02%, other results are all in experimental error scope. This research method may apply in the spectrum survey methane gas density, it has characteristics including high precision, strong selectivity, fast response and so on. 展开更多
关键词 coal mine gas absorption line intensity multi-line Voigt fitting spectrum survey
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基于窄带频谱分析的电力线载波通信干扰过滤技术 被引量:1
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作者 李俊 唐智灵 《电子器件》 CAS 2024年第2期442-447,共6页
电力线路载波通信受到背景噪声、脉冲噪声等方面干扰因素影响,导致通信信号质量下降,为此提出一种基于窄带频谱分析的通信干扰过滤技术。首先构建近似模型分析通信信号特征,利用马尔可夫链模拟信道上脉冲噪声状态。然后基于窄带频谱分... 电力线路载波通信受到背景噪声、脉冲噪声等方面干扰因素影响,导致通信信号质量下降,为此提出一种基于窄带频谱分析的通信干扰过滤技术。首先构建近似模型分析通信信号特征,利用马尔可夫链模拟信道上脉冲噪声状态。然后基于窄带频谱分析算法,在信号频谱周期图下,利用正交数据窗分离直接频谱,筛选估计方差以避免频谱泄漏事件的发生。利用傅里叶变换计算特征频谱,估计信号能量的集中特性,分析通信信号,平衡信号振幅和干扰抑制。最后通过时频峰值实施干扰滤波,有效保证电力线载波通信信号质量。经过实验数据分析证明,所提技术的载波干扰幅值最小值为1.1 dB,载波通信信号误码率平均值为1.9%,方法耗时平均值为3.8 s。 展开更多
关键词 电力线载波 信号抗干扰 频谱感知 傅里叶变换 窄带频谱分析
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基于随机森林的发电机定子线棒局部放电图谱特征识别方法 被引量:1
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作者 胡建林 张翕 +3 位作者 宋展 向紫馨 邓鸿飞 蒋兴良 《高电压技术》 EI CAS CSCD 北大核心 2024年第3期1272-1280,共9页
发电机定子线棒局部放电的在线监测和故障诊断对于电机故障预警、故障定位和指导机组检修有重要意义。目前存在部分不同类型局部放电相似度高,模式识别方法计算时间过长的问题,需要高精度和高效的识别方法,为此提出一种基于随机森林的... 发电机定子线棒局部放电的在线监测和故障诊断对于电机故障预警、故障定位和指导机组检修有重要意义。目前存在部分不同类型局部放电相似度高,模式识别方法计算时间过长的问题,需要高精度和高效的识别方法,为此提出一种基于随机森林的定子线棒局部放电识别方法。制备了6种类型定子线棒,用特高频天线检测局部放电信号,基于相位分布局部放电(PRPD)图谱比对,提出参数幅值不对称度。基于随机森林方法识别缺陷类型,计算特征重要性,选择有效特征。最后,可视化特征相似度,与传统反向传播(BP)神经网络方法对比,验证有效性。结果表明:随机森林算法可以有效识别人工缺陷定子线棒局部放电,总体识别正确率达到93.33%。筛选半数特征后,随机森林比BP神经网络的准确率提高了10.83%,特征选择对随机森林的准确率影响很小,但识别效率大幅提高。随机森林在少量特征时识别准确率、计算时间都明显优于神经网络。幅值不对称度参数的重要性排在全部特征前1/3,具有推广价值。 展开更多
关键词 定子线棒 局部放电 在线监测 随机森林 PRPD图谱
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燃煤锅炉温度场与高温腐蚀气氛场同步在线检测装置开发及应用 被引量:2
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作者 王建荣 程银雪 +6 位作者 李龙 郭古青 田亚莉 孙小聪 周月婷 李传亮 邱选兵 《电力科技与环保》 2024年第2期116-124,共9页
燃煤锅炉主燃区燃烧场的经济性、安全性和环保性对于智慧电厂建设具有重要意义。其中,水冷壁近壁面高温腐蚀H_(2)S和CO气体浓度的实时在线监测尤为重要。为实现燃煤锅炉主燃区温度场和高温腐蚀气氛场的同步测量,基于红外热成像原理,采用... 燃煤锅炉主燃区燃烧场的经济性、安全性和环保性对于智慧电厂建设具有重要意义。其中,水冷壁近壁面高温腐蚀H_(2)S和CO气体浓度的实时在线监测尤为重要。为实现燃煤锅炉主燃区温度场和高温腐蚀气氛场的同步测量,基于红外热成像原理,采用Optris-PI1M小型红外热成像仪,基于LabVIEW温度实时采集应用软件,在炉膛的观察口对主燃区温度场进行连续监测。以低成本1.5μm附近的通信波段激光器作为测量高温腐蚀气体H_(2)S和CO的激光光源,并结合波长调制光谱技术和频分复用技术,以实现H_(2)S和CO气体浓度的同步检测。线性度实验表明,其线性拟合相关系数为0.9995。将研制的同步检测仪器对某300 MW四角切圆燃煤锅炉的主燃区的温度场和气氛场进行了现场应用试验。现场测试结果表明,锅炉主燃区温度主要分布范围在1300~1400℃,最高温度达到了1500℃;同时得到了锅炉主燃区的H_(2)S和CO浓度分布,H_(2)S浓度在12~125 mg/m^(3)的范围内波动,而CO浓度主要分布在10%~20%之间,最高可达22%;炉内H_(2)S和CO的浓度呈正相关,氧气浓度保持在1%以下,由于厌氧燃烧会导致两种气体的含量增加,从而造成对水冷壁近壁面的高温腐蚀。 展开更多
关键词 燃煤锅炉 高温腐蚀 红外热成像 激光吸收光谱 在线监测
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船用机械系统线谱展频技术研究
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作者 孙国仓 陈虹 +1 位作者 张苗 刘宏 《舰船科学技术》 北大核心 2024年第4期57-60,共4页
机械系统线谱噪声是重要的水声探测和识别特征,减振降噪技术主要针对其量级进行控制。针对线谱能量在频域集中的特征,提出一种展频运行策略,可在功能不变的同时将其能量在频域进行展宽,削弱其可供识别的频域特征。船用离心泵台架试验表... 机械系统线谱噪声是重要的水声探测和识别特征,减振降噪技术主要针对其量级进行控制。针对线谱能量在频域集中的特征,提出一种展频运行策略,可在功能不变的同时将其能量在频域进行展宽,削弱其可供识别的频域特征。船用离心泵台架试验表明,提出的展频运行策略工程可行,随着频率分辨率的细化降低线谱峰值的效果可达7~15 dB。 展开更多
关键词 线谱噪声 展频运行 机械系统
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新能源汽车电池的在线监测与原位分析技术
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作者 吴玉 刘丽敏 黄华 《储能科学与技术》 CAS CSCD 北大核心 2024年第4期1335-1337,共3页
为控制新能源汽车电池耗电量,并对其电能消耗行为进行原位分析,针对新能源汽车电池的在线监测与原位分析技术展开研究。完善动力锂电池组结构模型,根据汽车电池的热耦合特性,推导监测核函数,实现新能源汽车电池的在线监测。在此基础上,... 为控制新能源汽车电池耗电量,并对其电能消耗行为进行原位分析,针对新能源汽车电池的在线监测与原位分析技术展开研究。完善动力锂电池组结构模型,根据汽车电池的热耦合特性,推导监测核函数,实现新能源汽车电池的在线监测。在此基础上,确定汽车电池的电极材料,并分别从表征特性、拉曼光谱两个角度,对其电池元件的原位特性进行研究。 展开更多
关键词 新能源汽车 在线监测 原位分析 热耦合特性 表征特性 拉曼光谱
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