STOCHASTIC RESONANCE IN A BALANCED PAIR OF SINGLE-ELECTRON BOXES

2011 ◽  
Vol 10 (03) ◽  
pp. 267-275 ◽  
Author(s):  
TAKAHIDE OYA ◽  
ALEXANDRE SCHMID ◽  
TETSUYA ASAI ◽  
AKIRA UTAGAWA
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Stochastic Resonance ◽  
Thermal Noise ◽  
Noise Suppression ◽  
Signal To Noise Ratio ◽  
Single Electron ◽  
Signal To Noise ◽  
Thermal Agitation ◽  
Internal States

Stochastic resonance in a fundamental single-electron circuit, i.e., a balanced pair of single-electron boxes, is observed and presented theoretically, where the signal-to-noise ratio (SNR) of the internal states stimulated by responding to a periodic subthreshold or suprathreshold input is enhanced by thermal agitation in tunneling junctions. Through extensive Monte-Carlo simulations, the peak SNR was determined as a function of temperature and input amplitudes. These results imply the possibility to design single-electron circuits that may "exploit" thermal noise, instead of employing conventional noise-suppression strategies.

A Novel Frequency Locked Loop Based on Stochastic Resonance

2013 ◽  
Vol 347-350 ◽  
pp. 1763-1767
Author(s):  
Wei Tong Zhang ◽  
Zhi Qiang Li ◽  
Wen Ming Zhu
Keyword(s):  
Stochastic Resonance ◽  
Thermal Noise ◽  
Signal To Noise Ratio ◽  
Dynamic Performance ◽  
Tracking Accuracy ◽  
Carrier Synchronization ◽  
Signal To Noise ◽  
Frequency Discriminator ◽  
Simulation Results ◽  
High Dynamics

Frequency locked loop (FLL) plays an important role in carrier synchronization because of its excellent dynamic performance. However, it performs inadequately in low signal-to-noise ratio (SNR). In this paper, the principle of stochastic resonance (SR) is briefly introduced and a SR processor is proposed. Based on traditional FLL, the SR processor is added before frequency discriminator in order to weaken the effect that thermal noise brings to FLL. The paper investigates the processing effect of SR. Simulation results show that the performance of improved FLL is greatly improved. It can tolerate rather high dynamics and tracking accuracy of frequency achieve 0.2Hz even with CNR as low as 25 dBHz, which verified the validity of above ideas.

scholarly journals Stochastic resonance in periodically driven bistable systems subjected to anomalous diffusion

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
F. Naha Nzoupe ◽  
Alain M. Dikandé
Keyword(s):  
Stochastic Resonance ◽  
Signal To Noise Ratio ◽  
Planck Equation ◽  
Relevant Information ◽  
Periodic Signal ◽  
Signal To Noise ◽  
Periodically Driven ◽  
Loop Area ◽  
Bistable Systems ◽  
Noise Ratio

AbstractThe occurrence of stochastic resonance in bistable systems undergoing anomalous diffusions, which arise from density-dependent fluctuations, is investigated with an emphasis on the analytical formulation of the problem as well as a possible analytical derivation of key quantifiers of stochastic resonance. The nonlinear Fokker–Planck equation describing the system dynamics, together with the corresponding Ito–Langevin equation, is formulated. In the linear response regime, analytical expressions of the spectral amplification, of the signal-to-noise ratio and of the hysteresis loop area are derived as quantifiers of stochastic resonance. These quantifiers are found to be strongly dependent on the parameters controlling the type of diffusion; in particular, the peak characterizing the signal-to-noise ratio occurs only in close ranges of parameters. Results introduce the relevant information that, taking into consideration the interactions of anomalous diffusive systems with a periodic signal, can provide a better understanding of the physics of stochastic resonance in bistable systems driven by periodic forces.

STOCHASTIC RESONANCE IN CHUA’S CIRCUIT DRIVEN BY AMPLITUDE OR FREQUENCY MODULATED SIGNALS

1994 ◽  
Vol 04 (02) ◽  
pp. 441-446 ◽  
Author(s):  
V.S. ANISHCHENKO ◽  
M.A. SAFONOVA ◽  
L.O. CHUA
Keyword(s):  
Numerical Simulation ◽  
Stochastic Resonance ◽  
Signal To Noise Ratio ◽  
Point Of View ◽  
Chua’S Circuit ◽  
Signal Distortion ◽  
Signal To Noise ◽  
Chua's Circuit ◽  
Noise Ratio ◽  
Modulated Signals

Using numerical simulation, we establish the possibility of realizing the stochastic resonance (SR) phenomenon in Chua’s circuit when it is excited by either an amplitude-modulated or a frequency-modulated signal. It is shown that the application of a frequency-modulated signal to a Chua’s circuit operating in a regime of dynamical intermittency is preferable over an amplitude-modulated signal from the point of view of minimizing the signal distortion and maximizing the signal-to-noise ratio (SNR).

Picking noisy refraction data using semblance supplemented by a Monte Carlo procedure and spectral balancing

1987 ◽  
Vol 77 (3) ◽  
pp. 942-957
Author(s):  
C. A. Zelt ◽  
J. J. Drew ◽  
M. J. Yedlin ◽  
R. M. Ellis
Keyword(s):  
Monte Carlo ◽  
Cross Correlation ◽  
Signal To Noise Ratio ◽  
Time Shift ◽  
Head Wave ◽  
Signal To Noise ◽  
Seismic Section ◽  
Monte Carlo Procedure ◽  
Noise Ratio ◽  
Refraction Data

Abstract In crustal refraction experiments, the crucial deeply refracted and head wave arrivals often have a low signal-to-noise ratio. A method to aid in the picking of noisy refraction data is presented which is applicable to any branch of a seismic section whose waveform is approximately invariant throughout the branch. The technique exploits the spatial correlation of arrivals and is based on the lateral coherency which results if the refracted arrivals are aligned by applying appropriate time shifts to each trace of the branch. The alignment of arrivals occurs iteratively and is accomplished through a cross-correlation of each trace with the stack of the section of the previous iteration. The iteration yielding the section with the highest degree of lateral coherency (semblance) is used to extract the travel-time pick of each trace. The pick, plus a possible d.c. component, is the negative of the time shift required to achieve arrival alignment. Two modifications can improve the performance of the picking routine. To prevent a cycle skipping problem, a Monte Carlo technique is implemented in which the cross-correlation function is transformed into a probability distribution so that the lag corresponding to the maximum cross-correlation is most probably selected. Second, to increase the coherency of the arrivals, a spectral balancing technique is applied in either the time or frequency domain. The picking routine is applied to both a synthetic and real data example, and the results suggest that the routine can be applied successfully to data with a signal-to-noise ratio as low as one. Also, the Monte Carlo procedure together with spectral balancing increases the final semblance over that obtained with the unmodified method.

Material decomposition for simulated dual-energy breast computed tomography via hybrid optimization method

2020 ◽  
Vol 28 (6) ◽  
pp. 1037-1054
Author(s):  
Temitope E. Komolafe ◽  
Qiang Du ◽  
Yin Zhang ◽  
Zhongyi Wu ◽  
Cheng Zhang ◽  
...  
Keyword(s):  
Dictionary Learning ◽  
Breast Tissue ◽  
Noise Suppression ◽  
Signal To Noise Ratio ◽  
Optimization Method ◽  
Dual Energy ◽  
Hybrid Optimization ◽  
Signal To Noise ◽  
Breast Ct ◽  
Different Levels

BACKGROUND: Dual-energy breast CT reconstruction has a potential application that includes separation of microcalcification from healthy breast tissue for assisting early breast cancer detection. OBJECTIVE: To investigate and validate the noise suppression algorithm applied in the decomposition of the simulated breast phantom into microcalcification and healthy breast. METHODS: The proposed hybrid optimization method (HOM) uses a simultaneous algebraic reconstruction technique (SART) output as a prior image, which is then incorporated into the self-adaptive dictionary learning. This self-adaptive dictionary learning seeks each group of patches to faithfully represent the learned dictionary, and the sparsity and non-local similarity of group patches are used to enforce the image regularization term of the prior image. We simulate a numerical phantom by adding different levels of Gaussian noise to test performance of the proposed method. RESULTS: The mean value of peak signal-to-noise ratio (PSNR), structural similarity (SSIM), and root mean square error (RMSE) for the proposed method are (49.043±1.571), (0.997±0.002), (0.003±0.001) and (51.329±1.998), (0.998±0.002), (0.003±0.001) for 35 kVp and 49 kVp, respectively. The PSNR of the proposed method shows greater improvement over TWIST (5.2%), SART (34.6%), FBP (40.4%) and TWIST (3.7%), SART (39.9%), FBP (50.3%) for 35 kVp and 49 kVp energy images, respectively. For the proposed method, the signal-to-noise ratio (SNR) of decomposed normal breast tissue (NBT) is (22.036±1.535), which exceeded that of TWIST, SART, and FBP by 7.5%, 49.6%, and 96.4%, respectively. The results reveal that the proposed algorithm achieves the best performance in both reconstructed and decomposed images under different levels of noise and the performance is due to the high sparsity and good denoising ability of minimization exploited to solve the convex optimization problem. CONCLUSIONS: This study demonstrates the potential of applying dual-energy reconstruction in breast CT to detect and separate clustered MCs from healthy breast tissues without noise amplification. Compared to other competing methods, the proposed algorithm achieves the best noise suppression performance for both reconstructed and decomposed images.

scholarly journals Monte Carlo Investigation of Shot-noise Suppression in Nondegenerate Ballistic and Diffusive Transport Regimes

2000 ◽  
Vol 53 (1) ◽  
pp. 3 ◽  
Author(s):  
L. Reggiani ◽  
A. Reklaitis ◽  
T. González ◽  
J. Mateos ◽  
D. Pardo ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Active Region ◽  
Inelastic Scattering ◽  
Shot Noise ◽  
Noise Suppression ◽  
Signal To Noise Ratio ◽  
Diffusive Transport ◽  
Poisson Solver ◽  
Diffusive Regime ◽  
Shot Noise Suppression

We review recent theoretical investigations of shot-noise suppression in nondegenerate semiconductor structures surrounded by two contacts acting as thermal reservoirs. Calculations make use of an ensemble Monte Carlo simulator self-consistently coupled with a one-dimensional Poisson solver. By taking the doping of the injecting contacts and the applied voltage as variable parameters, the influence of elastic and inelastic scattering as well as of tunneling between heterostructures in the active region is investigated. In the case of a homogeneous structure at T = 300 K the transition from ballistic to diffusive transport regimes under different contact injecting statistics is analysed and discussed. Provided significant space-charge effects take place inside the active region, long-range Coulomb interaction is found to play an essential role in suppressing shot noise at applied voltages much higher than the thermal value. In the elastic diffusive regime, momentum space dimensionality is found to modify the suppression factor γ, which within numerical uncertainty takes values respectively of about ⅓, ½ and 0·7 in the 3D, 2D and 1D cases. In the inelastic diffusive regime, shot noise is suppressed to the thermal value. In the case of single and multiple barrier non-resonant heterostructures made by GaAs/AlGaAs at 77 K, the mechanism of suppression is identified in the carrier inhibition to come back to the emitter contact after having been reflected from a barrier. This condition is realised in the presence of strong inelastic scattering associated with emission of optical phonons. At increasing applied voltages for a two-barrier structure, shot noise is suppressed up to about a factor of 0·50 in close analogy with the corresponding resonant barrier-diode. For an increasing number of barriers, shot noise is found to be systematically suppressed to a more significant level by following approximately a 1/(N + 1) behaviour, N being the number of barriers. This mechanism of suppression is expected to conveniently improve the signal-to-noise ratio of these devices.

scholarly journals Shielding of Piezoelectric Ultrasonic Probes in Hall Effect Imaging

1998 ◽  
Vol 20 (3) ◽  
pp. 206-220 ◽  
Author(s):  
Han Wen ◽  
Eric Bennett ◽  
David G. Wiesler
Keyword(s):  
Hall Effect ◽  
Electromagnetic Interference ◽  
Thermal Noise ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Excitation Pulse ◽  
Signal To Noise ◽  
Coherent Noise ◽  
Electrical Pulses ◽  
Coupling Mechanisms

This paper addresses significant sources of electromagnetic noise in Hall effect imaging. Hall effect imaging employs large electrical pulses for signal generation and high sensitivity ultrasonic probes for signal reception. Coherent noise arises through various coupling mechanisms between the excitation pulse and the probe. In this paper, the coupling mechanisms are experimentally isolated and theoretically analyzed. Several methods of shielding the probe from electromagnetic interference are devised and tested. These methods are able to reduce the noise to levels below the random thermal noise, thereby improving the signal-to-noise ratio in HEI by two orders of magnitude.

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