scholarly journals A fast DFT method for generally k sparse signals recovery

2019 ◽  
Vol 1 (11) ◽  
Author(s):  
Irfan Tariq ◽  
Meng Qiao
Keyword(s):  
Fourier Transforms ◽  
Dft Method ◽  
New Method ◽  
Sparse Signals ◽  
Original Signal ◽  
Discrete Fourier Transforms ◽  
Recovery Performance ◽  
Simulation Results ◽  
The Moment

Abstract In this paper, a new method to fast compute DFT of generally sparse signals is presented. Firstly, the original signal is downsampled with different time shifts, and the discrete Fourier Transforms (DFTs) of downsampled signals are calculated by FFT. Then the DFTs are used to determine and measure the K non-zero (significant) freq. grids by combining the moment preserving problem with the BigBand method. The proposed method is hardware-friendly, and simulation results show that the proposed method has better recovery performance compared with other methods.

scholarly journals Performance of Implementing Smart DFT in Micro Phasor Measurement Unit

2018 ◽  
Vol 69 ◽  
pp. 01005
Author(s):  
Chao-Yuan Lai ◽  
Tien-Yen Yang ◽  
Chih-Wen Liu
Keyword(s):  
Power System ◽  
Fourier Transforms ◽  
Dft Method ◽  
Phasor Measurement Unit ◽  
Measurement Unit ◽  
Digital Measurement ◽  
Waveform Generator ◽  
Discrete Fourier Transforms ◽  
Frequency Information ◽  
Phasor Measurement

The advance of the signal processing, this paper implement a more accurate digital measurement algorithm, Smart DFT(SDFT) in Micro Phasor Measurement Unit(μPMU), which is based on Discrete Fourier Transforms(DFT) to estimate frequency information from Taiwan power system. μPMU, the sensor we plan to acquire the information from the power system by using the signal of outlet voltage-level 110V in Taiwan, such as frequency, voltage and angle. The performance of SDFT implemented in μPMU represents a more precise frequency information when frequency fluctuation occurred just as the frequency of power system. We offer the results of simulations, stable frequency generated from waveform generator and real frequency from main electricity to compare SDFT with DFT method which implemented in μPMU.

scholarly journals A new method to identify the mass parameters of spacecraft

2020 ◽  
Vol 29 (1) ◽  
pp. 107-123
Author(s):  
Dongbo Meng ◽  
Xia Li ◽  
Jianguo Pang ◽  
Jianxin Lu
Keyword(s):  
Numerical Analysis ◽  
Least Squares ◽  
Condition Number ◽  
Moment Of Inertia ◽  
New Method ◽  
Mass Properties ◽  
Optimal Excitation ◽  
Mathematical Equations ◽  
Simulation Results ◽  
The Moment

AbstractA two-step identification method is proposed, both the moment of inertia and the mass properties are identified. A new index parameter which is different from the commonly used condition number is first defined for designing the optimal excitation. A method is introduced based on the least squares algorithm. Detailed mathematical equations and numerical analysis are proposed. Simulation results show that the proposed method can identify the mass parameters of spacecraft.

Transfers with a rendezvous lasting no more than one orbit between close near-circular coplanar orbits

2020 ◽  
pp. 82-93
Author(s):  
Aleksandr F. BRAGAZIN ◽  
Alexey V. USKOV
Keyword(s):  
Key Words ◽  
Relative Velocity ◽  
Free Parameter ◽  
Space Station ◽  
Characteristic Velocity ◽  
Orbital Station ◽  
Orbit Transfer ◽  
Simulation Results ◽  
The Moment ◽  
Phase Differences

Consideration has been given to orbit transfers involving spacecraft rendezvous which belong to a class of coplanar non-intersecting near-circular orbits of a spacecraft and a space station. The duration of the transfer is assumed to be limited by one orbit. The feasibility of a rendezvous using an optimal two-burn orbit-to-orbit transfer is studied. To determine a single free parameter of the transfer, i.e. the time of its start, ensuring a rendezvous at a given time or at a given velocity at the end of transfer, appropriate equations have been obtained To implement in the guidance algorithms optimal three-burn correction programs are proposed to achieve a rendezvous at a given time with a specified relative velocity at the moment of spacecraft contact. A range of phase differences at the start of maneuvering is determined, within which the characteristic velocity of the rendezvous is equal to the minimum characteristic velocity of the orbit-to-orbit transfer. The paper presents simulation results for “quick" rendezvous profiles that use the proposed programs. Key words: spacecraft, orbital station, “quick” rendezvous, orbit transfer, rendezvous program.

scholarly journals Cell shape characterization and classification with discrete Fourier transforms and self-organizing maps

2017 ◽  
Vol 93 (3) ◽  
pp. 323-333 ◽  
Author(s):  
Fabian L. Kriegel ◽  
Ralf Köhler ◽  
Jannike Bayat-Sarmadi ◽  
Simon Bayerl ◽  
Anja E. Hauser ◽  
...  
Keyword(s):  
Cell Shape ◽  
Fourier Transforms ◽  
Self Organizing Maps ◽  
Discrete Fourier Transforms ◽  
Shape Characterization ◽  
Self Organizing

Dual-Hop Amplify-and-Forward Variable Gain Relaying over Mixture Gamma Fading Channels

2015 ◽  
Vol 719-720 ◽  
pp. 767-772
Author(s):  
Wei Jun Cheng
Keyword(s):  
Fading Channels ◽  
Signal To Noise Ratio ◽  
Symbol Error Rate ◽  
Amplify And Forward ◽  
Variable Gain ◽  
Average Symbol Error Rate ◽  
Simulation Results ◽  
End To End ◽  
The Moment ◽  
Relaying System

In this paper, we present the end-to-end performance of a dual-hop amplify-and-forward variablegain relaying system over Mixture Gamma distribution. Novel closed-form expressions for the probability density function and the moment-generation function of the end-to-end Signal-to-noise ratio (SNR) are derived. Moreover, the average symbol error rate, the average SNR and the average capacity are found based on the above new expressions, respectively. These expressions are more simple and accuracy than the previous ones obtained by using generalized-K (KG) distribution. Finally, numerical and simulation results are shown to verify the accuracy of the analytical results.

scholarly journals High-Bandpass Filters in Electrocardiography: Source of Error in the Interpretation of the ST Segment

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
F. Buendía-Fuentes ◽  
M. A. Arnau-Vives ◽  
A. Arnau-Vives ◽  
Y. Jiménez-Jiménez ◽  
J. Rueda-Soriano ◽  
...  
Keyword(s):  
Real Time ◽  
Fourier Transforms ◽  
Pass Filter ◽  
Discrete Fourier Transforms ◽  
Real Time Mode ◽  
Asymptomatic Patients ◽  
St Segment ◽  
Coronary Syndromes ◽  
Clinically Significant ◽  
High Pass

Introduction. Artifactual variations in the ST segment may lead to confusion with acute coronary syndromes. Objective. To evaluate how the technical characteristics of the recording mode may distort the ST segment. Material and Method. We made a series of electrocardiograms using different filter configurations in 45 asymptomatic patients. A spectral analysis of the electrocardiograms was made by discrete Fourier transforms, and an accurate recomposition of the ECG signal was obtained from the addition of successive harmonics. Digital high-pass filters of 0.05 and 0.5 Hz were used, and the resulting shapes were compared with the originals. Results. In 42 patients (93%) clinically significant alterations in ST segment level were detected. These changes were only seen in “real time mode” with high-pass filter of 0.5 Hz. Conclusions. Interpretation of the ST segment in “real time mode” should only be carried out using high-pass filters of 0.05 Hz.

A New Method of Rolling Prediction for Gas Emission Based on Wavelet Neural Network

2011 ◽  
Vol 383-390 ◽  
pp. 1500-1506
Author(s):  
Yu Min Pan ◽  
Xiao Yu Zhang ◽  
Peng Qian Xue
Keyword(s):  
Neural Network ◽  
Input Data ◽  
Wavelet Neural Network ◽  
New Method ◽  
Neutral Network ◽  
Gas Emission ◽  
Sample Data ◽  
Simulation Results

A new method of rolling prediction for gas emission based on wavelet neural network is proposed in this paper. In the method, part of the sample data is selected, which length is constant, and the data is reselected as the next prediction step. Then a wavelet neutral network is adopted to prediction which input data is rolling, the sequence model of rolling prediction is thus constructed. Simulation results have proved that the method is valid and feasible.

Sign in / Sign up

Export Citation Format

Share Document