排序方式: 共有53条查询结果,搜索用时 15 毫秒
1.
讨论了一种用于∑-△A/D转换器的固定系数半带(half-band)FIR数字滤波器,分析了其线性相位特性和低通滤波特性,给出了频率仿真结果,以及在Cadence设计系统中的电路和版图实现。 相似文献
2.
从工程实际出发,给出了一种基于新型Cortex-M3内核ARM和MEMS惯性传感器的低成本、高性能微型惯性测量单元的结构框架。详细介绍了采用三轴MEMS陀螺、三轴MEMS加速度计和三轴磁阻传感器研制的微惯性测量单元硬件设计方案,分析了陀螺和加速度计的信号噪声,利用均值滤波法对信号进行预处理,对预处理后的信号采用FIR滤波器进行滤波,对陀螺和加速度计进行了标定。该测量单元已应用于某小型无人机的姿态测量,达到预期效果。 相似文献
3.
In this study, we propose a set of new algorithms to enhance the effectiveness of classification for 5-year survivability of breast cancer patients from a massive data set with imbalanced property. The proposed classifier algorithms are a combination of synthetic minority oversampling technique (SMOTE) and particle swarm optimization (PSO), while integrating some well known classifiers, such as logistic regression, C5 decision tree (C5) model, and 1-nearest neighbor search. To justify the effectiveness for this new set of classifiers, the g-mean and accuracy indices are used as performance indexes; moreover, the proposed classifiers are compared with previous literatures. Experimental results show that the hybrid algorithm of SMOTE + PSO + C5 is the best one for 5-year survivability of breast cancer patient classification among all algorithm combinations. We conclude that, implementing SMOTE in appropriate searching algorithms such as PSO and classifiers such as C5 can significantly improve the effectiveness of classification for massive imbalanced data sets. 相似文献
4.
The problem of oversampling parameter estimation for noisy sinusoidal signals is addressed. We first extend the weighted least squares (WLS) approach to the complex sinusoids. Then the oversampling weighted least squares (OSWLS) estimator is proposed based on data decimation. Estimation performance of the OSWLS method is analyzed via theoretical and simulation studies. Results are also compared to those of the WLS and decimative unitary ESPRIT methods as well as Cramér-Rao lower bound. 相似文献
5.
This paper presents a novel over-sampling method based on document content to handle the class imbalance problem in text classification. The new technique, COS-HMM (Content-based Over-Sampling HMM), includes an HMM that is trained with a corpus in order to create new samples according to current documents. The HMM is treated as a document generator which can produce synthetical instances formed on what it was trained with.To demonstrate its achievement, COS-HMM is tested with a Support Vector Machine (SVM) in two medical documental corpora (OHSUMED and TREC Genomics), and is then compared with the Random Over-Sampling (ROS) and SMOTE techniques. Results suggest that the application of over-sampling strategies increases the global performance of the SVM to classify documents. Based on the empirical and statistical studies, the new method clearly outperforms the baseline method (ROS), and offers a greater performance than SMOTE in the majority of tested cases. 相似文献
6.
在数字音频技术中,过取样可以降低量化噪声,但却带来一种新的噪声,即空闲信道噪声。本文叙述空闲信道噪声的产生过程,以及有要用加上抖晃信号以消除空闲信道噪声的方法。并以数字调幅发射机为例来说明抖晃信号的应用。 相似文献
7.
8.
为了兼顾数字锁相检测的速度和精度,提高信号检测系统的综合性能,该文提出了一种基于数字锁相相关计算结构的高速算法并结合过采样对算法性能优化。该方法在过采样的基础上将采样频率还原为4倍于原信号的频率,快速数字锁相算法对下抽样后q个周期的4q个采样点进行加减法运算即可实现,与传统数字锁相算法相比几乎消除了所有的乘法运算,大幅度地提高了数字锁相算法实现的速度。同时引入修正因子改善了由于降采样所带来的误差。实验结果表明,该方法既有过采样和锁相检测的高精度,能够检测到较低信噪比的信号,又具备较高的速度,使得该算法对微弱信号的实时检测在普通微处理器上的实现成为可能。 相似文献
9.
10.