A Deterministic Approach to Process Noise Attenuation in a Communication Satellite Driven by White Noise Sequence

Seismic noise attenuation is an important step in seismic data processing. Most noise attenuation algorithms are based on the analysis of time-frequency characteristics of the seismic data and noise. We have aimed to attenuate white noise of seismic data using the convolutional neural network (CNN). Traditional CNN-based noise attenuation algorithms need prior information (the “clean” seismic data or the noise contained in the seismic) in the training process. However, it is difficult to obtain such prior information in practice. We assume that the white noise contained in the seismic data can be simulated by a sufficient number of user-generated white noise realizations. We then attenuate the seismic white noise using the modified denoising CNN (MDnCNN). The MDnCNN does not need prior clean seismic data nor pure noise in the training procedure. To accurately and efficiently learn the features of seismic data and band-limited noise at different frequency bandwidths, we first decomposed the seismic data into several intrinsic mode functions (IMFs) using variational mode decomposition and then apply our denoising process to the IMFs. We use synthetic and field data examples to illustrate the robustness and superiority of our method over the traditional methods. The experiments demonstrate that our method can not only attenuate most of the white noise but it also rejects the migration artifacts.

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Effects of neuronal norepinephrine uptake blockade on baroreflex neural and peripheral arc transfer characteristics

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00527.2003 ◽

2004 ◽

Vol 286 (6) ◽

pp. R1110-R1120 ◽

Cited By ~ 13

Author(s):

Toru Kawada ◽

Tadayoshi Miyamoto ◽

Kazunori Uemura ◽

Koji Kashihara ◽

Atsunori Kamiya ◽

...

Keyword(s):

Transfer Function ◽

Sympathetic Nerve ◽

Neuronal Uptake ◽

Arterial Baroreflex ◽

Exogenous Disturbance ◽

Sympathetic Regulation ◽

White Noise Sequence ◽

Noise Sequence ◽

Normalized Gain ◽

Sinus Pressure

Neuronal uptake is the most important mechanism by which norepinephrine (NE) is removed from the synaptic clefts at sympathetic nerve terminals. We examined the effects of neuronal NE uptake blockade on the dynamic sympathetic regulation of the arterial baroreflex because dynamic characteristics are important for understanding the system behavior in response to exogenous disturbance. We perturbed intracarotid sinus pressure (CSP) according to a binary white noise sequence in anesthetized rabbits, while recording cardiac sympathetic nerve activity (SNA), arterial pressure (AP), and heart rate (HR). Intravenous administration of desipramine (1 mg/kg) decreased the normalized gain of the neural arc transfer function from CSP to SNA relative to untreated control (1.03 ± 0.09 vs. 0.60 ± 0.08 AU/mmHg, mean ± SE, P < 0.01) but did not affect that of the peripheral arc transfer function from SNA to AP (1.10 ± 0.05 vs. 1.08 ± 0.10 mmHg/AU). The normalized gain of the transfer function from SNA to HR was unaffected (1.01 ± 0.04 vs. 1.09 ± 0.12 beats·min−1·AU−1). Desipramine decreased the natural frequency of the transfer function from SNA to AP by 28.7 ± 7.0% (0.046 ± 0.007 vs. 0.031 ± 0.002 Hz, P < 0.05) and that of the transfer function from SNA to HR by 64.4 ± 2.2% (0.071 ± 0.003 vs. 0.025 ± 0.002 Hz, P < 0.01). In conclusion, neuronal NE uptake blockade by intravenous desipramine administration reduced the total buffering capacity of the arterial baroreflex mainly through its action on the neural arc. The differential effects of neuronal NE uptake blockade on the dynamic AP and HR responses to SNA may provide clues for understanding the complex pathophysiology of cardiovascular diseases associated with neuronal NE uptake deficiency.

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Bezold-Jarisch reflex attenuates dynamic gain of baroreflex neural arc

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01082.2002 ◽

2003 ◽

Vol 285 (2) ◽

pp. H833-H840 ◽

Cited By ~ 16

Author(s):

Koji Kashihara ◽

Toru Kawada ◽

Yusuke Yanagiya ◽

Kazunori Uemura ◽

Masashi Inagaki ◽

...

Keyword(s):

Transfer Function ◽

Myocardial Ischemia ◽

Dynamic Characteristics ◽

Acute Myocardial Ischemia ◽

Renal Sympathetic Nerve Activity ◽

Afferent Nerves ◽

Before And After ◽

White Noise Sequence ◽

Noise Sequence ◽

Dynamic Gain

Although acute myocardial ischemia or infarction may induce the Bezold-Jarisch (BJ) reflex through the activation of serotonin receptors on vagal afferent nerves, the mechanism by which the BJ reflex modulates the dynamic characteristics of arterial pressure (AP) regulation is unknown. The purpose of this study was to examine the effects of the BJ reflex induced by intravenous phenylbiguanide (PBG) on the dynamic characteristics of the arterial baroreflex. In seven anesthetized rabbits, we perturbed intracarotid sinus pressure (CSP) according to a white noise sequence while renal sympathetic nerve activity (RSNA), AP, and heart rate (HR) were recorded. We estimated the transfer function from CSP to RSNA (neural arc) and from RSNA to AP (peripheral arc) before and after 10 min of intravenous administration of PBG (100 μg · kg–1 · min–1). The intravenous PBG decreased mean AP from 84.5 ± 4.0 to 68.2 ± 4.7 mmHg ( P < 0.01), mean RSNA to 76.2 ± 7.0% ( P < 0.05), and mean HR from 301.6 ± 7.7 to 288.4 ± 9.0 beats/min ( P < 0.01). The intravenous PBG significantly decreased neural arc dynamic gain at 0.01 Hz (1.06 ± 0.08 vs. 0.59 ± 0.17, P < 0.05), whereas it did not affect that of the peripheral arc (1.20 ± 0.12 vs. 1.18 ± 0.41). In six different rabbits without intravenous PBG, the neural arc transfer function did not change between two experimental runs with intervening interval of 10 min, excluding the possibility that the cumulative effects of anesthetics had altered the neural arc transfer function. In conclusion, excessive activation of the BJ reflex during acute myocardial ischemia may exert an adverse effect on AP regulation, not only by sympathetic suppression, but also by attenuating baroreflex dynamic gain.

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Time Series Analysis of Pulmonary Tuberculosis Incidence: Forecasting by Applying the Time Series Model

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.709.819 ◽

2013 ◽

Vol 709 ◽

pp. 819-822 ◽

Cited By ~ 1

Author(s):

Yin Ping Chen ◽

Ai Ping Wu ◽

Cui Ling Wang ◽

Hai Ying Zhou ◽

Shu Xiu Feng

Keyword(s):

Time Series ◽

Pulmonary Tuberculosis ◽

Moving Average ◽

Arima Model ◽

Autoregressive Integrated Moving Average ◽

Tuberculosis Incidence ◽

Short Lead Time ◽

White Noise Sequence ◽

Noise Sequence ◽

Residual Sequence

The main objective of this study is to identify the stochastic autoregressive integrated moving average (ARIMA) model to predict the pulmonary tuberculosis incidence in Qianan. Considering the Box-Jenkins modeling approach, the incidence of pulmonary tuberculosis was collected monthly from 2004 to 2010. The model ARIMA(0,1,1)12 was established finally and the residual sequence was a white noise sequence. Then, this model was used for calculating dengue incidence for the last 6 observations compared with observed data, and performed to predict the monthly incidence in 2011. It is necessary and practical to apply the approach of ARIMA model in fitting time series to predict pulmonary tuberculosis within a short lead time.

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Adaptive Two-stage Kalman Filter for SINS/Odometer Integrated Navigation Systems

Journal of Navigation ◽

10.1017/s0373463316000485 ◽

2016 ◽

Vol 70 (2) ◽

pp. 242-261 ◽

Cited By ~ 2

Author(s):

Hongsong Zhao ◽

Lingjuan Miao ◽

Haijun Shao

Keyword(s):

Kalman Filter ◽

Navigation System ◽

Scale Factor ◽

Navigation Systems ◽

Integrated Navigation ◽

Two Stage ◽

Integrated Navigation System ◽

White Noise Sequence ◽

Noise Sequence ◽

Computation Load

In Strapdown Inertial Navigation System (SINS)/Odometer (OD) integrated navigation systems, OD scale factor errors change with roadways and vehicle loads. In addition, the random noises of gyros and accelerometers tend to vary with time. These factors may cause the Kalman filter to be degraded or even diverge. To address this problem and reduce the computation load, an Adaptive Two-stage Kalman Filter (ATKF) for SINS/OD integrated navigation systems is proposed. In the Two-stage Kalman Filter (TKF), only the innovation in the bias estimator is a white noise sequence with zero-mean while the innovation in the bias-free estimator is not zero-mean. Based on this fact, a novel algorithm for computing adaptive factors is presented. The proposed ATKF is evaluated in a SINS/OD integrated navigation system, and the simulation results show that it is effective in estimating the change of the OD scale factor error and robust to the varying process noises. A real experiment is carried out to further validate the performance of the proposed algorithm.

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Environmental Noise Mitigation by Plenum Window with Sonic Crystals and Jagged Flap

Fluctuation and Noise Letters ◽

10.1142/s0219477519500019 ◽

2019 ◽

Vol 18 (01) ◽

pp. 1950001 ◽

Cited By ~ 2

Author(s):

Hsiao Mun Lee ◽

Andi Haris ◽

Kian Meng Lim ◽

Jinlong Xie ◽

Heow Pueh Lee

Keyword(s):

White Noise ◽

Experimental Studies ◽

Environmental Noise ◽

Noise Attenuation ◽

Frequency Range ◽

Noise Mitigation ◽

Numerical Studies ◽

Narrow Frequency Range ◽

Sonic Crystals

A plenum window with incorporation of rectangular sonic crystals (SCs) in between two glass panes was tested in a reverberation room. Before the start of the experiment, numerical studies were performed on the whole structure in order to prove the effectiveness of the SCs in enhancing the noise attenuation performance of the plenum window. The effects of flat and jagged flaps on reducing strength of diffracted sound were also investigated in the experimental studies. White, traffic and construction noises were examined during each measurement. When the frequencies were ranging from 100[Formula: see text]Hz to 5000[Formula: see text]Hz, the plenum window with SCs without flap was able to attenuate 9.5, 8.5 and 8.6[Formula: see text]dBA of white, traffic and construction noises, respectively, compared with the case of without window. The effects of flat flaps on noise attenuation performance of the plenum window were negligible while the jagged flap was able to attenuate additional 1.7[Formula: see text]dBA of white noise and 1.6[Formula: see text]dBA of traffic and construction noises compared with the case of without flap. In the narrow frequency range of 900–1300[Formula: see text]Hz, the plenum window with SCs without flap was able to reduce additional 2.7, 2.3 and 2.5[Formula: see text]dBA of white, traffic and construction noises, respectively, compared with the case of without SCs.

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