期刊文献+
共找到11篇文章
< 1 >
每页显示 20 50 100
基于最小均方差法的局部脑血容积计算的研究
1
作者 陈杰 李颖 +2 位作者 王荣仁 何任杰 饶利芸 《生物医学工程学杂志》 EI CAS CSCD 北大核心 2014年第6期1207-1211,共5页
本文采用基于傅里叶变换的最小均方差(MMSE)法对磁共振灌注成像中局部脑血容积(rCBV)进行了计算,针对磁共振灌注成像过程中存在测量噪声干扰的问题,对算法进行了改进。实验对比了信噪比(SNR)为50dB环境下的rCBV和采用MMSE法进行处理的rC... 本文采用基于傅里叶变换的最小均方差(MMSE)法对磁共振灌注成像中局部脑血容积(rCBV)进行了计算,针对磁共振灌注成像过程中存在测量噪声干扰的问题,对算法进行了改进。实验对比了信噪比(SNR)为50dB环境下的rCBV和采用MMSE法进行处理的rCBV,分析了不同SNRs对脑血容积的影响。实验结果表明,采用MMSE法处理灌注图像可以很好地滤除测量噪声,准确地计算脑血容积。与现有其他方法相比,该方法对环境的敏感度小,尤其适合处理SNR较大的环境中获得的灌注图像。 展开更多
关键词 磁共振灌注成像 局部脑血容积 最小均方差法 信噪比
原文传递
建筑节能设计评价指标筛选方法研究
2
作者 侯凤武 郭伟 《河北建筑工程学院学报》 CAS 2012年第4期41-44,共4页
首先介绍了建筑能耗及建筑节能评价指标研究现状,研究了指标的筛选方法,通过对比与选择,对熵值法、最小均方差法进行了分析和研究,并结合建筑节能评价的指标体系,通过案例分析计算验证了方法的有效性.
关键词 熵值 最小均方差法 建筑节能 指标体系
下载PDF
叙永一矿煤层突出预测敏感指标及其临界值确定 被引量:4
3
作者 邢长勇 杨瀚 +2 位作者 黄光平 张东明 蒋志刚 《煤炭技术》 CAS 2020年第11期83-86,共4页
针对叙永一矿实际瓦斯地质条件,将钻屑量指标S和钻孔瓦斯解吸指标K1作为其煤层突出危险性预测的敏感指标,并以历史数据和现场测得的数据为基础,确定了煤层的钻屑量S和钻屑瓦斯解吸指标K1的临界值分别为5.20 kg/m和0.41 mL/(g·min1... 针对叙永一矿实际瓦斯地质条件,将钻屑量指标S和钻孔瓦斯解吸指标K1作为其煤层突出危险性预测的敏感指标,并以历史数据和现场测得的数据为基础,确定了煤层的钻屑量S和钻屑瓦斯解吸指标K1的临界值分别为5.20 kg/m和0.41 mL/(g·min1/2)。通过最小均方差法对煤层突出预测指标进行敏感性分析发现,钻屑量指标S的敏感性相对于钻屑瓦斯解吸指标K1较好,其敏感指标及临界值对叙永一矿后续防突措施的制定和瓦斯治理方案设计具有现实指导意义。 展开更多
关键词 煤与瓦斯突出 敏感指标 钻屑瓦斯解吸指标 钻屑量 最小均方差法
下载PDF
Novel registration algorithm for 3-D images captured from multiple views of object surface
4
作者 衡伟 《Journal of Southeast University(English Edition)》 EI CAS 2005年第4期411-413,共3页
A novel algorithm of 3-D surface image registration is proposed. It makes use of the array information of 3-D points and takes vector/vertex-like features as the basis of the matching. That array information of 3-D po... A novel algorithm of 3-D surface image registration is proposed. It makes use of the array information of 3-D points and takes vector/vertex-like features as the basis of the matching. That array information of 3-D points can be easily obtained when capturing original 3-D images. The iterative least-mean-squared (LMS) algorithm is applied to optimizing adaptively the transformation matrix parameters. These can effectively improve the registration performance and hurry up the matching process. Experimental results show that it can reach a good subjective impression on aligned 3-D images. Although the algorithm focuses primarily on the human head model, it can also be used for other objects with small modifications. 展开更多
关键词 image alignment 3-D image 3-D capture image registration iterative least-mean-squared algorithm
下载PDF
Design of nuclear radiation level gauge based on normalized LMS filtering correction 被引量:1
5
作者 WU Zuo-peng WANG Xiao-peng WU Xu 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第2期103-108,共6页
In the measurement of liquid level in industrial site environment,noise interference can affect the measurement accuracy.In order to improve the measurement accuracy of liquid level in the viscous state,a nuclear radi... In the measurement of liquid level in industrial site environment,noise interference can affect the measurement accuracy.In order to improve the measurement accuracy of liquid level in the viscous state,a nuclear radiation level measurement system based on the least mean square(LMS)filtering correction method is designed.The system uses STM32F103 as the control core and adopts HART bus HT1200M chip for remote signal transmission and reception.The adaptive LMS algorithm can be used for more accurate filtering,calculating iterative weight vector,updating weighted coefficient,effectively removing system measurement noise and improving the measurement accuracy.The results show that the nuclear radiation level gauge based on normalized LMS can correct the measurement system accuracy in adaptive rules,improve the measurement accuracy to meet the requirements of industrial field environment for liquid level measurement and enhance the industrial automation control degree. 展开更多
关键词 least mean square(LMS) nuclear radiation method self-adaptive algorithm weighted coefficient updating level gauge
下载PDF
Online model identification of lithium-ion battery for electric vehicles 被引量:3
6
作者 胡晓松 孙逢春 邹渊 《Journal of Central South University》 SCIE EI CAS 2011年第5期1525-1531,共7页
In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery o... In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was established.The battery open circuit voltage (OCV) as a function of state of charge (SOC) was depicted by the Nernst equation.An equivalent circuit network was adopted to describe the polarization effect of the lithium-ion battery.A linear identifiable formulation of the battery model was derived by discretizing the frequent-domain description of the battery model.The recursive least square algorithm with forgetting was applied to implement the on-line parameter calibration.The validation results show that the on-line calibrated model can accurately predict the dynamic voltage behavior of the lithium-ion battery.The maximum and mean relative errors are 1.666% and 0.01%,respectively,in a hybrid pulse test,while 1.933% and 0.062%,respectively,in a transient power test.The on-line parameter calibration method thereby can ensure that the model possesses an acceptable robustness to varied battery loading profiles. 展开更多
关键词 battery model on-line parameter identification lithium-ion battery electric vehicle
下载PDF
Hardware implementation of adaptive filter for noise cancellation using TMS320C6713
7
作者 Swati S Godbole Sanjay B Pokle 《Journal of Measurement Science and Instrumentation》 CAS 2014年第3期38-47,共10页
Daily, we experience the effects of audio noise, which contaminates the original information bearing signal with noise from its surrounding environment. This paper focuses on real-time hardware implementation of multi... Daily, we experience the effects of audio noise, which contaminates the original information bearing signal with noise from its surrounding environment. This paper focuses on real-time hardware implementation of multi-tap adaptive noise cancellation (ANC) system by using the least mean square (LMS) algorithm on TMS320C6713 to remove undesired noise from a received signal for various audio related applications. Three different experiments are carried out by considering different audio inputs to test the efficiency of the designed ANC system. The 'C' code implementation of LMS algorithm is introduced and simulated in code composer studio (CCS), then realized on the digital signal processor (DSP) C6713. The 300 Hz, 500 Hz, 800 Hz, 1 kHz and 3 kHz of tone signals and male speech signal are used as the reference inputs to trace the noise of signal until it is eliminated. The performance of ANC system is studied in terms of convergence speed, order of the filter and signal-to-noise ratio (SNR). The experimentam results demonstrate that the designed system shows a consider- able improvement in SNR. 展开更多
关键词 adaptive noise cancellation (ANC) digital signal processor (DSP) mean square error (MSE) least mean squarealgorithm (LMS) TMS320C6713 DSK code composer studio (CCS) signal-to-noise ratio (SNR)
下载PDF
Semi-Blind Pilot-Aided Channel Estimation in Uplink Cloud Radio Access Networks 被引量:1
8
作者 Yourong Ban Qiang Hu +1 位作者 Zhendong Mao Zhongyuan Zhao 《China Communications》 SCIE CSCD 2016年第9期72-79,共8页
In this paper, a quasi-Newton method fbr semi-blind estimation is derived for channel estimation in uplink cloud radio access networks (C-RANs). Different from traditional pilot-aided estimation, semiblind estimatio... In this paper, a quasi-Newton method fbr semi-blind estimation is derived for channel estimation in uplink cloud radio access networks (C-RANs). Different from traditional pilot-aided estimation, semiblind estimation utilizes the unknown data symbols in addition to the known pilot symbols to estimate the channel. An initial channel state information (CSI) obtained by least-squared (LS) estimation is needed in semi-blind estimation. BFGS (Brayben, Fletcher, Goldfarb and Shanno) algorithm, which employs data as well as pilot symbols, estimates the CSI though solving the problem provided by maximum-likelihood (ML) principle. In addition, mean-square-error (MSE) used to evaluate the estimation performance can be further minimized with an optimal pilot design. Simulation results show that the semi-blind estimation achieves a significant improvement in terms of MSE performance over the conventional LS estimation by utilizing data symbols instead of increasing the number of pilot symbols, which demonstrates the estimation accuracy and spectral efficiency are both improved by semiblind estimation for C-RANs. 展开更多
关键词 cloud radio access networks semi-blind channel estimation
下载PDF
基于多传感器估值融合理论的地质灾害变形监测方法研究
9
作者 黄明坚 《甘肃地质》 2023年第4期74-78,共5页
在开展地质灾害变形监测的过程中,由于传感器采集数据结果会受到客观环境的影响而出现异常情况,导致对变形情况的监测结果与实际情况存在较大误差,为此,提出基于多传感器估值融合理论的地质灾害变形监测方法研究。在对多传感器数据进行... 在开展地质灾害变形监测的过程中,由于传感器采集数据结果会受到客观环境的影响而出现异常情况,导致对变形情况的监测结果与实际情况存在较大误差,为此,提出基于多传感器估值融合理论的地质灾害变形监测方法研究。在对多传感器数据进行预处理阶段,引入了估值融合理论,具体采用的融合算法为最小误差均方差法,利用其对传感器采集数据结果中的异常值进行校正。在变形监测阶段,充分利用了多个数据源(传感器)对同一目标进行观测时的特征构成,结合观测特征、实时状态数据与发展函数三者之间的关系,实现对地质灾害变形情况的有效监测。在测试结果中,设计方法能够获取某地铁隧道水平方向上和垂直方向上的位移结果,具有较高的可靠性和精度。 展开更多
关键词 多传感器 估值融合理论 地质灾害变形 最小误差均方差 发展函数
原文传递
Raman spectroscopy de-noising based on EEMD combined with VS-LMS algorithm 被引量:3
10
作者 俞潇 许亮 +1 位作者 莫家庆 吕小毅 《Optoelectronics Letters》 EI 2016年第1期16-19,共4页
This paper proposes a novel de-noising algorithm based on ensemble empirical mode decomposition(EEMD) and the variable step size least mean square(VS-LMS) adaptive filter.The noise of the high frequency part of spectr... This paper proposes a novel de-noising algorithm based on ensemble empirical mode decomposition(EEMD) and the variable step size least mean square(VS-LMS) adaptive filter.The noise of the high frequency part of spectrum will be removed through EEMD,and then the VS-LMS algorithm is utilized for overall de-noising.The EEMD combined with VS-LMS algorithm can not only preserve the detail and envelope of the effective signal,but also improve the system stability.When the method is used on pure R6G,the signal-to-noise ratio(SNR) of Raman spectrum is lower than 10dB.The de-noising superiority of the proposed method in Raman spectrum can be verified by three evaluation standards of SNR,root mean square error(RMSE) and the correlation coefficient ρ. 展开更多
关键词 ALGORITHMS Mean square error Raman scattering System stability
原文传递
Simulation research on a minimum root-mean-square error rotation-fitting algorithm for gravity matching navigation 被引量:12
11
作者 WANG HuBiao WANG Yong +2 位作者 FANG Jian CHAI Hua ZHENG Hui 《Science China Earth Sciences》 SCIE EI CAS 2012年第1期90-97,共8页
Gravity/inertial combination navigation is a leading issue in realizing passive navigation onboard a submarine. A new rotation-fitting gravity matching algorithm, based on the Terrain Contour Matching (TERCOM) algorit... Gravity/inertial combination navigation is a leading issue in realizing passive navigation onboard a submarine. A new rotation-fitting gravity matching algorithm, based on the Terrain Contour Matching (TERCOM) algorithm, is proposed in this paper. The algorithm is based on the principle of least mean-square-error criterion, and searches for a certain matched trajectory that runs parallel to a trace indicated by an inertial navigation system on a gravity base map. A rotation is then made clockwise or counterclockwise through a certain angle around the matched trajectory to look for an optimal matched trajectory within a certain angle span range, and through weighted fitting with another eight suboptimal matched trajectories, the endpoint of the fitted trajectory is considered the optimal matched position. In analysis of the algorithm reliability and matching error, the results from simulation indicate that the optimal position can be obtained effectively in real time, and the positioning accuracy improves by 35% and up to 1.05 nautical miles using the proposed algorithm compared with using the widely employed TERCOM and SITAN methods. Current gravity-aided navigation can benefit from implementation of this new algorithm in terms of better reliability and positioning accuracy. 展开更多
关键词 Terrain Contour Matching algorithm minimum root-mean-square error rotation of coordinates weighted fit gravityaided navigation
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部