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Gear is one of the most important components in rotary machine systems. The vibration signals generated from gearbox show strong nonlinearity or chaotic behavior. To identify the complex nonlinear behavior of gear faults, recurrence network is introduced to extract features of gear vibration under different conditions. Quantitative characteristics (such as mean degree centrality, global clustering...
Prediction for deck-motion is a practical measure to improve the landing/taking off safety of carrier-based aircraft when those deck-motions in six-degree freedoms cannot be effectively controlled/restrained. Deck-motions excited by waves and winds own characteristics of randomness and nonlinearity. It is generally believed those classical feed-forward neural networks, such as back propagation networks...
In order to improve the signal noise ratio (SNR) and signal interference ratio (SIR) of the output speech signal and extract pure target speech in the environment with strong noises and interferences, a novel target speech extraction method based on multiple reference signals independent component analysis (ICA) algorithm is proposed in this paper. The reference signals are acquired by source localization,...
JSD-I/A quartz flexural gravitational sensor (JQFGS) is an important component of the underwater navigation gravimeter, and the method of denoising the output signal of JQFGS by time series analysis and adaptive kalman filtering is researched. Firstly, the time-series models of JQFGS's signal are analyzed, and AR(3), AR(4) and AR(5) models are used to approximate the output system equation of JQFGS...
The sea gravimeters are widely applied to the reconnaissance of the sea oil and gas field, the perambulation of the sea terrestrial heat resource and the gravity passive navigation of underwater vehicles. The signal denosing method of the JSD-I/A quartz flexural gravitational sensor (JQFGR) is one key technology of the sea gravimeters, and the wavelet denosing method of JQFGR'S signal is researched...
Abstract-The problem of optimizing the AGC reference level for OFDM-based telecommunication systems is studied in this paper. We first give a statistical model of the OFDM signal envelop, then derive the power of granular noise and clipping distortion introduced by the analog-to-digital converter. The overall distortion which is related to AGC reference level is discussed and closed form expression...
The complexity of the conventional post Discrete Fourier Transform (DFT) Maximal Ratio Combining may exceed the processing ability of a low-end OFDM receiver. In this paper, we propose a new combining architecture which can reduce the complexity by using cyclic delay combining and orthogonal design simultaneously. Simulation results show that this architecture works well in the OFDM system.
The removal of dissolved oxygen (DO) from water was studied experimentally in a Pd-resin base catalyst reactor using purified hydrogen gas as a reducing agent. The effects of various operating conditions, such as hydrogen and water flow rates, height of the catalytic resin bed, temperature, pH value and run time, on the removal of DO, had been studied extensively. The results shows that DO could be...
In this paper, a novel clipping noise mitigation algorithm for OFDM system with large clipping ratio is proposed. We notice that the situation that there is only one sample above the clipping level appears with a large probability and the clipping noise on each subcarrier can be estimated in this case. Simulation result shows that the proposed algorithm can mitigate the clipping noise effectively.
The conventional one-tap equalizer for OFDM based communication systems fails to eliminate the ISI and ICI introduced by multipath propagation when the Channel Impulse Response (CIR) length exceeds the duration of Guard Interval (GI). We propose, in this paper, a new equalization scheme for the suppression of insufficient GI generated interference using redundancy provided by the guard bands. Simulation...
The conventional over-lapping-add equalizer for ZP-OFDM based broadcasting systems fails to eliminate the ISI and ICI introduced by multipath propagation when the channel impulse response (CIR) length exceeds the duration of guard interval (GI). We propose, in this paper, a new equalization scheme for the suppression of insufficient GI generated interference using inherent diversity property of ZP-OFDM...
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