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最优基

最优基的相关文献在1988年到2022年内共计79篇,主要集中在自动化技术、计算机技术、无线电电子学、电信技术、经济计划与管理 等领域,其中期刊论文76篇、会议论文2篇、专利文献211191篇;相关期刊68种,包括三峡大学学报(人文社会科学版)、运筹与管理、预测等; 相关会议2种,包括全国高校机械工程测试技术研究会振动工程学会动态测绘专业委员会2008代表大会暨学术年会、中国优选法统筹法与经济数学研究会2003第五届中国管理科学年会等;最优基的相关文献由157位作者贡献,包括李慧、丁晓莺、左宪章等。

最优基—发文量

期刊论文>

论文:76 占比:0.04%

会议论文>

论文:2 占比:0.00%

专利文献>

论文:211191 占比:99.96%

总计:211269篇

最优基—发文趋势图

最优基

-研究学者

  • 李慧
  • 丁晓莺
  • 左宪章
  • 冯登超
  • 刘林
  • 周康
  • 周文娟
  • 唐力伟
  • 唐娜
  • 师小红
  • 期刊论文
  • 会议论文
  • 专利文献

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    • 李钦
    • 摘要: 本文通过三个实例探讨了线性规划问题退化解的单纯形法求解。退化可能带来单纯形法求解效率下降,在高度退化情形下,进基变量或离基变量选择不当,可能陷入退化循环;退化可能导致最优解的误判或遗漏。当线性规划问题存在退化最优解时,多重最优解的判定准则失效,最优解具有唯一性,但最优基可能有多个。
    • 田晟; 韩巍; 王婷婷
    • 摘要: 为了优化煤岩压裂声发射信号的降噪效果,采用小波变换与小波包变换相结合的方法,利用MATLAB软件的小波包降噪函数,分别对3种不同脆性矿物含量的煤岩压裂声发射信号进行了降噪处理.提出在运用小波包降噪算法的前提下,在常见小波基中选取最优基,可提高分析效率且降噪效果良好;选取测试时间相同的数据进行分析,是正确选择降噪层数的必要条件;结合多种评价指标进行综合分析,进而确定最佳的降噪层数,可有效避免降噪不足或降噪过度.实验结果表明,对脆性矿物含量为30%、50%、70%的煤岩压裂声发射信号进行小波包降噪处理的最优基分别为Sym2、Sym6、Sym5,且最佳降噪层数均为3层.SymN小波系最适合煤岩压裂声发射信号的降噪,N值的选取与煤岩的脆性矿物含量有关,且在DbN小波系、CoifN小波系中,各自的最优基均具有较小的N值.随着煤岩脆性矿物含量的增加,SymN小波系相对于其他2种小波系在小波包降噪效果上表现出的优势越加明显.%In order to optimize the de-noise effect,the paper adopt the method of wavelet transform to combine with wavelet packet transform,and use the wavelet packet de-noise function of MATLAB software to take de-noise processing about the acoustic emission experiment signal,which the signal is from coal rock fracturing of three kinds of brittle mineral content.And the paper puts forward that on the premise of applying wavelet packet de-noise algorithmic,we improve to analyze efficiency and obtained good de-noise effect;choosing and analyzing the data at the same testing time is the requirement of determining the best number of plies;combining with various evaluation index and generalized analysis and then confirm the best number of plies could effectively avoid de-noising deficiency or de-nosing excessive.The experiment results indicate that the signal of three kinds of coal rock samples those mineral content are 30%,50%,70% and respectively the best wavelet basis is Sym2,Sym6,Sym5,and the best number of these plies is three.SymN wavelet is best for denosing of the coal rock fracturing acoustic emission signal,which the value of N relates to mineral content of rock.In the DbN and CoifN wavelet,each wavelet has smaller value of N.With the increasing of brittle mineral content,the SymN has more obvious advantage of denoise effect relative to other two kinds of wavelet have.
    • 王益艳
    • 摘要: In clinical testing,as a typical physiological signal,ECG (ECG) is often accompanied by the acquisition frequency interference,baseline drift and EMG interference influence.For subsequent diagnosis can be effective,it must be pretreated with ECG signal acquisition.This paper presents an ECG signal noise reduction method based on wavelet packet analysis,Firstly,the best wavelet packet basis was selected with entropy criteria,then the ECG signals was decomposed multilayer with wavelet packet,finally,the reconstructed signal was obtained after decomposition coefficients threshold quantization.The fetal ECG signal simulation results show that the wavelet packet analysis method has better noise reduction than the Fourier transform and wavelet transform.%在临床医学检测上,心电信号(ECG)是一种典型的人体生理信号,在采集时常伴有工频干扰、基线漂移和肌电干扰等影响.为后续能进行有效诊断,必须对采集的ECG信号进行预处理.文中介绍了一种基于小波包分析的ECG信号降噪方法,首先根据熵标准选择最佳小波包基,然后对ECG信号进行多层小波包分解,最后对分解系数进行阈值量化后得到重构信号.通过对胎儿ECG信号的仿真实验,结果表明,小波包分析方法比傅里叶变换和小波变换等具有更好的降噪效果.
    • 田晟 韩巍 王婷婷
    • 摘要: 为了优化煤岩压裂声发射信号的降噪效果,采用小波变换与小波包变换相结合的方法,利用MATLAB软件的小波包降噪函数,分别对3种不同脆性矿物含量的煤岩压裂声发射信号进行了降噪处理。提出在运用小波包降噪算法的前提下,在常见小波基中选取最优基,可提高分析效率且降噪效果良好;选取测试时间相同的数据进行分析,是正确选择降噪层数的必要条件;结合多种评价指标进行综合分析,进而确定最佳的降噪层数,可有效避免降噪不足或降噪过度。实验结果表明,对脆性矿物含量为30%、50%、70%的煤岩压裂声发射信号进行小波包降噪处理的最优基分别为Sym2、Sym6、Sym5,且最佳降噪层数均为3层。SymN小波系最适合煤岩压裂声发射信号的降噪,N值的选取与煤岩的脆性矿物含量有关,且在DbN小波系、CoifN小波系中,各自的最优基均具有较小的N值。随着煤岩脆性矿物含量的增加,SymN小波系相对于其他2种小波系在小波包降噪效果上表现出的优势越加明显。
    • 赵丁凤; 陈国兴; 陈苏; 戚承志; 杜修力
    • 摘要: 以模型结构整体剪切刚度量化微粒混凝土和石膏模型结构的刚度比,根据小波包变换的频带分布特征确定频带与结点的输出关系,并基于最小熵准则的最优基选择算法,对比分析了不同刚度三层三跨地铁地下车站侧墙加速度反应的时频特性.研究结果表明:最优小波包变换方法具有自适应的频域分辨能力,能较好地解决频带重叠现象.采用最优基小波包变换技术能有效挖掘出由结构材料不同引起的模型结构加速度反应的时间-频率-能量之间的差异.在强震作用下,微粒混凝土模型结构加速度反应的特征频带总能量高于石膏模型结构;石膏模型结构加速度反应在0~6.25 Hz频带的能量集中程度高于微粒混凝土模型结构,在>6.25~ 12.5 Hz频带内的能量累积速率较微粒混凝土模型结构快;石膏模型结构加速度反应各特征频带进入快速能量累积的时刻均早于微粒混凝土结构.
    • 白泉; 韩晶晶; 盛国华; 张正帅
    • 摘要: 基于目标功率谱,本文从定量角度提出一种地震动反应谱拟合过程中小波基函数的选取方法。首先通过修正不同小波基函数所对应的小波系数来拟合地震动反应谱;然后设定总体误差绝对值和误差均方差这两个定量指标来描述各拟合波功率谱与目标功率谱的差异,借助数理统计的独立权数原理,求得不同小波基函数所对应的定量指标的综合评价值;最后对比综合评价值,得到拟合精度最高、误差离散最小的最优小波基。应用该方法,选取8种常见的小波基函数进行实例分析。结果表明,该方法得到的最优拟合波与原信号差异不大,拟合波反应谱、功率谱与目标反应谱、功率谱均吻合得较好,从而验证了该方法的正确性。%Based on the target power spectrum,this paper proposed a method for selecting wavelet basis function in the simulation of seismic response spectrum from a quantitative point of view.Firstly,we revised the different wavelet coefficients that correspond to different wavelet basis functions to simulate the seismic response spectrum.And then we set two quantitative indices,i.e ., overall error absolute values and mean square errors to describe the differences between the power spectrum of the simulated wave and the target power spec-trum.Using the principle of independent weight in mathematical statistics,we obtained the comprehensive evaluation values of the quantitative indices that correspond to the different wavelet basis functions.Finally,from all of the comprehensive evaluation values,we got the optimal wavelet basis with highest simulation accuracy and minimum discreteness of error.Using this method,we selected eight kinds of common wavelet basis functions for instance analysis. The results show that the optimal simulated wave based on this method has slight difference from the original signal,and simulated wave response spectrum coincides well with the target response spectrum,the same as power spectrum, verifying the correctness of the method proposed in this paper.
    • 路亮; 龙源; 谢全民; 刘好全; 赵长啸; 李兴华
    • 摘要: 针对工程爆破网络监测与预报系统对精度、效率的要求,提出将提升小波包最优基分解算法应用于爆破振动信号的降噪处理及能量特征提取。在提升小波包多尺度变换的基础上,通过对最优基搜索算法的改进满足了复杂信号在线处理对算法的需求,结合应用实例验证了该算法能够有效滤除实测信号中的干扰噪声,并准确获取信号在各频带的能量分布特征。提升小波包最优基分解算法在爆破振动信号分析中的应用为爆破振动危害的研究和控制提供了分析基础和技术支持,具有良好的应用前景。%Lifting wavelet packet decomposing algorithm based on optimal basis was applied in de-noising blast vibration signals and analysis of energy distribution in order to ensure the accuracy and efficiency of an engineering blasting network monitoring and forecasting system.Based on lifting wavelet packet multi-scale transformation,an improved search algorithm for optimal basis was used,it met the needs of online processing of complicated signals.In application examples,noise was filtered with the lifting wavelet packet decomposing algorithm,and the energy distribution of every frequency band was acquired precisely.The application of the proposed algorithm in analysing blasting vibration signals provided a study basis and technical supports for study and control of blasting vibration hazards.
    • 李姣军; 唐娜; 苏理云; 徐勤
    • 摘要: This paper proposed a new kind of optimum wavelet packet basis search algorithm.Based on the BBS(Best Basis Selection),the paper chose long energy entropy as the information cost function to search from bottom to top,and compared father node log energy entropy with son node,and marked min-entropy node until root node.According to mark-node,it constituted the wavelet packet tree,and then the structure would be the optimal wavelet packet basis.This algorithm has broken that Shannon as information cost function.This paper also simply introduced application field of this algorithm in the last.%提出了一种新的最优小波包基搜寻算法,在BBS(best basis selection)基础上,选择对数能量熵作为信息花费代价函数,自上而下搜索,将父节点对数能量熵与子节点和的对数能量熵进行比较,标记最小熵节点,直至标记到根节点,按所标记的节点构成小波包树,则此结构即为最优小波包基,此算法打破了一直以来以香农熵为代价函数的惯例。
    • 纪凤珠; 孙世宇; 王长龙; 左宪章; 王瑾
    • 摘要: Magnetic flux leakage (MFL) testing signals obtained from oil pipelines are usually contaminated by various sources of noises, and therefore the detectability of defect in MFL data is considerably reduced The fuzzy lifting wavelet packet was presented and used to solve the problem of noise reduction from the magnetic flux leakage (MFL) inspecting signals. Under the condition of three kind of threshold processing mode: soft-threshold,hard-threshold and fussy-threshold, the de-noising performance of proposed method was compared with traditional wavelet packet The simulation results showed that the fuzzy lifting wavelet packet de-noising method had the characteristic of fast operational speed and good de-noising effectiveness, so it was a valid on-line processing method of MFL inspecting signal.%漏磁(MFL)检测信号常被多种噪声源污染,极大地降低了漏磁信号中缺陷信号的可检测性.为此提出应用模糊提升小波包解决漏磁信号的噪声抑制问题.对比分析软阈值、硬阈值和模糊阈值三种阈值处理方式下,传统小波包与提升小波包的降噪性能,并应用模糊提升小波包实现了漏磁信号的降噪.仿真结果表明,该方法具有运算速度快,降噪效果好的特点,是一种有效的漏磁检测信号降噪方法.
    • 张瑞红; 林大超; 乔兰
    • 摘要: 应用最优小波包变换,采用取决于节点噪声时频特征的相关阈值,对模拟地震波到达的加噪合成信号、SDAES数字声发射仪采集的微震实验信号、NIED观测台站记录的日本2007年能登半岛地震信号进行去噪,并和基于小波变换的其他方法进行了去噪效果比较.结果表明,该方法获得的信号信噪比(SNR)高、失真低,体现出了总体优越性.%We apply the node-dependent threshold relative to the characteristics of the time-frequency of the noise to the optimum Wavelet Packet Transform (WPT) method to denoise a synthetic noisy signal of the arrival of the simulative seismic wave, an experimental micro-seismic signal collected by a digital acoustic emission instrument, SDAES, and a seismic signal of 2007 Noto Han to Earthquake in Japan recorded at NIED observatory. We find that the signal denoised by the optimum WPT method has a higher signal-to-noise ratio (SNR) and a lower distortion than those by other methods based on wavelet transform (WT) methods, and the WPT method shows the overall superiority.
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