Artículos de revistas: "Flicker (1/f) Noise"

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Klimontovich, Yu L. y J. P. Boon. "Natural Flicker Noise (“1/ f Noise”) in Music". Europhysics Letters (EPL) 3, n.º 4 (15 de febrero de 1987): 395–99. http://dx.doi.org/10.1209/0295-5075/3/4/002.

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Kousik, G. S., J. Gong, C. M. Van Vliet, G. Bosman, W. H. Ellis, E. E. Carroll y P. H. Handel. "Flicker-noise fluctuations in α-radioactive decay". Canadian Journal of Physics 65, n.º 4 (1 de abril de 1987): 365–75. http://dx.doi.org/10.1139/p87-043.

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Counting statistics of α particles from three sources, one containing 241Am; one containing 239Pu, 241Am, and 244Cu; and a source containing 148Gd, were determined over periods of 1–4000 min. In particular, the two-sample variance or Allan variance was determined for many sample runs. According to a recent theorem, there is a unique relation between the particle-flux spectral noise density and the Allan variance. It was found that for small counting periods, the statistics were Poissonian, corresponding to shot noise of the particle flux. For long periods[Formula: see text], the counting statistics were found to be non-Poissonian, indicating the presence of 1/f noise and (or) Lorentzian noise.The 1/f noise gave flicker floors of (0.5–0.7) × 10−7 for 239Pu, (1.0–1.3) × 10−7 for 241Am, and 3.0 × 10−7 for 244Cm. The Lorentzians were not reproducible in different runs and are probably associated with chemical oxidation-reduction rate processes in the source. The 1/f noise is likely inherent in the process of α-particle decay, indicating that the classical picture of alpha decay as a Poisson process is incomplete. Some forms of quantum 1/f noise associated with the tunnel-emission process are briefly discussed.

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Rovamo, J. y A. Raninen. "Modelling of Human Flicker Detection at Various Light Levels". Perception 25, n.º 1_suppl (agosto de 1996): 129. http://dx.doi.org/10.1068/v96l0609.

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Root-mean-square flicker sensitivity was measured within 0.2 – 2500 phot td and 0.5 – 30 Hz for a small spot with an equiluminous surround using computer graphics and a 2AFC method. In temporal noise, flicker sensitivity as a function of temporal frequency had a low-pass shape at all illuminances. Without temporal noise, the flicker sensitivity functions showed a band-pass shape at high illuminances, but changed to a low-pass shape at low illuminances. Our data are well described (goodness of fit 88%) by a model comprising: (i) low-pass temporal filtering by the modulation transfer function (MTF) of the photoreceptors ( R), (ii) high-pass temporal filtering by the MTF of the neural visual pathways ( P) resulting from lateral inhibition, (iii) addition of the temporal equivalent ( Nit) of internal neural noise, and (iv) detection by a temporal matched filter, provided that we take into account the fact that receptor responses become weaker and slower with decreasing illuminance despite adaptation. In our model detection efficiency was \eta( f)=0.148 f−0.568, Nit=46.3 μs and P( f) equal to f, where f is flicker frequency. In addition, R= R0[1+( f/ fc)2]−3, where R0=(1+24.1/ I)−0.5, fc=6.33 I0.172, and I is retinal illuminance. The model indicates that for the detection of a flickering spot in cone vision (i) the strength of lateral inhibition is independent of light level and (ii) quantal noise and dark light always remain insignificant sources of noise. (Mathematical expressions may not appear as intended)

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4

Cohen, Oded y Zvi Ovadyahu. "1/f NOISE NEAR THE METAL-INSULATOR TRANSITION". International Journal of Modern Physics B 08, n.º 07 (30 de marzo de 1994): 897–903. http://dx.doi.org/10.1142/s0217979294000440.

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The 1/f noise level in polycrystalline indium oxide thin films and of zinc oxide accumulation layers is found to be much higher than that usually observed in metals. A systematic study of the flicker noise properties in these systems reveals a correlation between the 1/f noise magnitude and the proximity of the system to the insulating phase. In fact, the noise appears to increase dramatically close to the Anderson transition but when the average transport properties exhibited by the system are still diffusive. For static disorder that exceeds the critical value characterized by KFl≃1 the system exhibits insulating behavior and the noise level saturates at a rather high, but disorder independent value. The similarity of these findings to the behavior of the magnetic-field-induced Conductance Fluctuations in this system will be pointed out to suggest a common physical origin. This leads to the prediction of high levels of 1/f in all electronic systems that are close to the metal-insulator transition.

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5

Kaulakys, Bronislovas, Miglius Alaburda y Julius Ruseckas. "1/f noise from the nonlinear transformations of the variables". Modern Physics Letters B 29, n.º 34 (20 de diciembre de 2015): 1550223. http://dx.doi.org/10.1142/s0217984915502231.

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The origin of the low-frequency noise with power spectrum [Formula: see text] (also known as [Formula: see text] fluctuations or flicker noise) remains a challenge. Recently, the nonlinear stochastic differential equations for modeling [Formula: see text] noise have been proposed and analyzed. Here, we use the self-similarity properties of this model with respect to the nonlinear transformations of the variables of these equations and show that [Formula: see text] noise of the observable may yield from the power-law transformations of well-known standard processes, like the Brownian motion, Bessel and similar stochastic processes. Analytical and numerical investigations of such techniques for modeling processes with [Formula: see text] fluctuations is presented.

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Pepper, G. T., T. J. Kennett y W. V. Prestwich. "A re-investigation of the possibility of 1/f noise fluctuations in α decay". Canadian Journal of Physics 67, n.º 5 (1 de mayo de 1989): 468–70. http://dx.doi.org/10.1139/p89-083.

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The fluctuations in counts observed for the α decay of 241Am have been analyzed for a possible 1/f component. The data indicate that if 1/f fluctuations exist, the associated flicker floor is probably less than 2 × 10−9.

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7

Ho, W. Y., W. K. Fong, C. Surya, K. Y. Tong, W. Kim, A. Botcharev y H. Morkoc. "Characterization of Flicker Noise in GaN Based Modfets at low Drain Bias". MRS Internet Journal of Nitride Semiconductor Research 4, S1 (1999): 565–69. http://dx.doi.org/10.1557/s1092578300003057.

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We report systematic characterizations of flicker noise in GaN based MODFETs. Flicker noise was measured across the channel of the devices from room temperature to 130 K. The voltage noise power spectra, SV(f) were found to be proportional to 1/fγ, where γ depends on the device temperature as well as the gate bias. Study of SV(f) as a function of the biasing condition was conducted in detail and was found to vary as VD2/(VG−VT)β where β changes with temperature from about 2.1 at room temperature to about 0.9 at 130K. Analyses of the data showed that the noise originated from thermal activation of carriers to localized states in the channel area. The data suggested that the trapping and detrapping of carriers did not lead to fluctuations in the carrier concentration as postulated in the McWhorter’s model. However, more work is needed to determine if surface mobility fluctuations played key role in the 1/f noise.

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8

LENOIR, BENJAMIN. "PREDICTING THE VARIANCE OF A MEASUREMENT WITH 1/f NOISE". Fluctuation and Noise Letters 12, n.º 01 (marzo de 2013): 1350006. http://dx.doi.org/10.1142/s0219477513500065.

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Measurement devices always add noise to the signal of interest and it is necessary to evaluate the variance of the results. This article focuses on stationary random processes whose power spectrum density is a power law of frequency. For flicker noise, behaving as 1/f and which is present in many different phenomena, the usual way to compute the variance leads to infinite values. This article proposes an alternative definition of the variance which takes into account the fact that measurement devises need to be calibrated. This new variance, which depends on the calibration duration, the measurement duration and the duration between the calibration and the measurement, allows avoiding infinite values when computing the variance of a measurement.

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9

Prestwich, W. V., T. J. Kennett y G. T. Pepper. "Comment on: Flicker-noise fluctuations in α-radioactive decay". Canadian Journal of Physics 66, n.º 1 (1 de enero de 1988): 100–101. http://dx.doi.org/10.1139/p88-014.

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A discrepancy between experiments to establish the existence of 1/f fluctuations in α decay is discussed. It is argued that the flicker floor reported for direct α counting cannot be due to fluctuations intrinsic to the decay process.

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10

Pelz, Jonathan, John Clarke y Wayne E. King. "Flicker (1/f) noise in copper films due to radiation-induced defects". Physical Review B 38, n.º 15 (15 de noviembre de 1988): 10371–86. http://dx.doi.org/10.1103/physrevb.38.10371.

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11

Miklich, A. H., John Clarke, M. S. Colclough y K. Char. "Flicker (1/f) noise in biepitaxial grain boundary junctions of YBa2Cu3O7−x". Applied Physics Letters 60, n.º 15 (13 de abril de 1992): 1899–901. http://dx.doi.org/10.1063/1.107147.

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12

Gesley, Mark y Lyn Swanson. "Thermal-field emission flicker (1/f) noise and diffusive equilibrium density fluctuations". Physical Review A 37, n.º 12 (1 de junio de 1988): 4879–902. http://dx.doi.org/10.1103/physreva.37.4879.

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13

Miguez, Matías y Alfredo Arnaud. "A Study of Flicker Noise in MOS Transistor Under Switched Bias Condition". Journal of Integrated Circuits and Systems 3, n.º 2 (18 de noviembre de 2008): 63–68. http://dx.doi.org/10.29292/jics.v3i2.283.

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This manuscript examines in detail the mechanisms and behavior of flicker noise in switched biased MOS transistors. Firstly, the PSD of a DC biased transistor is deduced using only Shockley-Read-Hall (SRH) statistics and the autocorrelation formalism. Then the analysis is extended, by means of simulations and using simple physical hypotheses, to a switched bias condition. The results allow explaining several reported experimental data. Particularly, the 1/f form of flicker noise at very low frequencies is observed in simulations.

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14

Jantsch, O. "Flicker (1/f) noise generated by a random walk of electrons in interfaces". IEEE Transactions on Electron Devices 34, n.º 5 (mayo de 1987): 1100–1115. http://dx.doi.org/10.1109/t-ed.1987.23051.

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15

Oh, Nam-Jin y Deuk Heo. "A low-power, low phase noise CMOS VCO with suppression of 1/f flicker noise up-conversion". IEICE Electronics Express 9, n.º 24 (2012): 1881–86. http://dx.doi.org/10.1587/elex.9.1881.

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16

Monnig, Curtis A. y Gary M. Hieftje. "An Investigation of Noise Amplitude Spectra Produced by a Direct-Current Plasma". Applied Spectroscopy 43, n.º 5 (julio de 1989): 742–46. http://dx.doi.org/10.1366/0003702894202283.

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Noise amplitude spectra for direct-current plasma atomic emission spectrometry (DCP-AES) were acquired. Flicker (1/ f) noise dominates the signal at low frequencies, and white noise prevails at higher frequencies. Broad-band audio-frequency (af) noise was observed in the plasma continuum emission when the nebulizer gas was directed into the discharge. By increasing the electrode-gas flows, it was possible to narrow the frequency range and increase the amplitude of this af noise. The introduction of an easily ionized element into the plasma had little effect on the noise characteristics of the source.

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17

Wellstood, F. C., C. Urbina y John Clarke. "Flicker (1∕f) noise in the critical current of Josephson junctions at 0.09–4.2K". Applied Physics Letters 85, n.º 22 (29 de noviembre de 2004): 5296–98. http://dx.doi.org/10.1063/1.1826236.

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18

Kim, Kyung Min, Hee Hwan Ji, In Shik Han, Seong Hyung Park, Hee Seung Lee, Young Seok Kang, Dae Byung Kim et al. "Dependency of 1/f Noise on Initial Oxidation Method in Nano-CMOS Technology". Solid State Phenomena 121-123 (marzo de 2007): 595–98. http://dx.doi.org/10.4028/www.scientific.net/ssp.121-123.595.

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In this paper, it is presented that flicker (1/f) noise of ultra thin gate oxide can be improved by initial oxidation and subsequent plasma nitridation(PN). PN which raises Nitrogen peak upward from the Si/Oxide interface to gate polysilicon/Oxide interface is adopted mainly to improve the life time such as Negative-Bias Temperature Instability (NBTI) and hot carrier in Nano CMOS technology. Three different types of initial oxidation prior to plasma nitridation are investigated. One is slow thermally grown oxide(STO) in very small Oxygen ambient, another is rapid thermally grown oxide(RTO) and the other is grown in Nitrous oxygen ambient (NO). Oxide thickness of all splits is about 14.5< Then, it is shown that STO has the lowest drain current noise power (Sid) among the splits. The interface trap densitie (Dit) of each oxide is characterized using charge pumping method. Finally, we reached a conclusion that the 1/f noise can be significantly reduced by initial STO and Plasma Nitridation in Nano CMOS technology.

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19

LIU, GUANXIONG, WILLIAM STILLMAN, SERGEY RUMYANTSEV, MICHAEL SHUR y ALEXANDER A. BALANDIN. "LOW-FREQUENCY ELECTRONIC NOISE IN GRAPHENE TRANSISTORS: COMPARISON WITH CARBON NANOTUBES". International Journal of High Speed Electronics and Systems 20, n.º 01 (marzo de 2011): 161–70. http://dx.doi.org/10.1142/s0129156411006490.

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We report results of the experimental investigation of the low-frequency noise in graphene transistors. The graphene devices were measured in three-terminal configuration. The measurements revealed low flicker noise levels with the normalized noise spectral density close to 1/f (f is the frequency) and the Hooge parameter αH ~10-3. Both top-gate and back-gate devices were studied. The analysis of the noise spectral-density dependence on the gate biases helped us to elucidate the noise sources in these devices. We compared the noise performance of graphene devices with that of carbon nanotube devices. It was determined that graphene devices works better than carbon nanotube devices in terms of the low-frequency noise. The obtained results are important for graphene electronic, communication and sensor applications.

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20

Blender, R., X. Zhu y K. Fraedrich. "Observations and modelling of 1/<i>f</i>-noise in weather and climate". Advances in Science and Research 6, n.º 1 (18 de mayo de 2011): 137–40. http://dx.doi.org/10.5194/asr-6-137-2011.

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Abstract. Data with power spectra close to S(f)~1/f is denoted as 1/f or flicker noise. High resolution measurements during TOGA/COARE for temperature, humidity, and wind speed (1\\,min resolution) reveal 1/f spectra while precipitation shows no power-law scaling during the same period. However, a binary time series indicating the precipitation events (1 for precipitation, 0 for no precipitation) shows a clear 1/f spectrum in line with the remaining boundary layer data. For extreme events in time series with 1/f spectra the return time distribution is well approximated by a Weibull-distribution for short and long return times. The daily discharge of the Yangtze river shows high volatility which is linked to the intra-annual 1/f spectrum. The discharge fluctuations detected in different time windows are represented by a single function (a so-called data collapse) similar to the universal behavior found for turbulence and various physical systems at criticality. The collapse is well described by the Gumbel distribution.

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21

Macků, Robert, Pavel Koktavý, Tomas Trčka y Vladimir Holcman. "Experimental Studies of Excess Noise Sources in Concrete Based Materials as a Limiting Factor for Electromagnetic Emission Measurement". Key Engineering Materials 592-593 (noviembre de 2013): 529–32. http://dx.doi.org/10.4028/www.scientific.net/kem.592-593.529.

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This paper deals with excess noise sources in dielectric materials. We focus especially on the concrete samples that are frequently tested to ensure information about the reliability and level of degradation. Nevertheless, the testing methods are limited mainly by the proper contact creation, signal detection and noise defined sensitivity. Our efforts are directed to the noise properties assessment. It turns out that the Johnson-Nyquist noise and the 1/f (flicker) noise are generated in the different regions with the different response to the internal or external electric field. In addition the noise analysis is affected by the internal polarization phenomena and the material residual humidity. This issue in connection with the sample geometrical properties and the dielectric noise measurement methodology take part in this paper.

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22

Durdaut, Phillip, Cai Müller, Anne Kittmann, Viktor Schell, Andreas Bahr, Eckhard Quandt, Reinhard Knöchel, Michael Höft y Jeffrey McCord. "Phase Noise of SAW Delay Line Magnetic Field Sensors". Sensors 21, n.º 16 (21 de agosto de 2021): 5631. http://dx.doi.org/10.3390/s21165631.

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Surface acoustic wave (SAW) sensors for the detection of magnetic fields are currently being studied scientifically in many ways, especially since both their sensitivity as well as their detectivity could be significantly improved by the utilization of shear horizontal surface acoustic waves, i.e., Love waves, instead of Rayleigh waves. By now, low-frequency limits of detection (LOD) below 100 pT/Hz can be achieved. However, the LOD can only be further improved by gaining a deep understanding of the existing sensor-intrinsic noise sources and their impact on the sensor’s overall performance. This paper reports on a comprehensive study of the inherent noise of SAW delay line magnetic field sensors. In addition to the noise, however, the sensitivity is of importance, since both quantities are equally important for the LOD. Following the necessary explanations of the electrical and magnetic sensor properties, a further focus is on the losses within the sensor, since these are closely linked to the noise. The considered parameters are in particular the ambient magnetic bias field and the input power of the sensor. Depending on the sensor’s operating point, various noise mechanisms contribute to f0 white phase noise, f−1 flicker phase noise, and f−2 random walk of phase. Flicker phase noise due to magnetic hysteresis losses, i.e. random fluctuations of the magnetization, is usually dominant under typical operating conditions. Noise characteristics are related to the overall magnetic and magnetic domain behavior. Both calculations and measurements show that the LOD cannot be further improved by increasing the sensitivity. Instead, the losses occurring in the magnetic material need to be decreased.

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23

Rumyantsev, Sergey L., Michael S. Shur, Michael E. Levinshtein, Pavel A. Ivanov, John W. Palmour, Mrinal K. Das y Brett A. Hull. "Low Frequency Noise in 4H-SiC MOSFETs". Materials Science Forum 615-617 (marzo de 2009): 817–20. http://dx.doi.org/10.4028/www.scientific.net/msf.615-617.817.

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Low-frequency noise in 4H-SiC MOSFETs has been measured for the first time. At drain currents varying from deep subthreshold to strong inversion, the 1/f (flicker) noise dominated at frequencies 1 - 105 Hz. The dependence of relative spectral noise density, , on drain current Id (at a constant drain voltage Vd) differs qualitatively from that in Si MOSFETs. In Si MOSFETs, ~ 1/ in strong inversion, whereas tends to saturate in sub-threshold. In 4H-SiC MOSFETs under study, ~ 1/ over the whole range of currents from deep sub-threshold to strong inversion. Similar noise behavior is often observed in poly- or a-Si TFTs. The effective channel mobility in 4H-SiC MOSFETs, 3 - 7 cm2/Vs, is also as low as that in TFTs. Both noise behavior and transport properties of 4H-SiC MOSFETs are explained, analogously to TFTs, by a high density of localized states (bulk and interface) near the conduction band edge in the ion implanted p-well.

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24

Ho, W. Y., W. K. Fong, Charles Surya, K. Y. Tong, L. W. Lu y W. K. Ge. "Characterization of Hot-Electron Effects on Flicker Noise in III-V Nitride Based Heterojunctions". MRS Internet Journal of Nitride Semiconductor Research 4, S1 (1999): 560–64. http://dx.doi.org/10.1557/s1092578300003045.

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We report experiments on hot-electron stressing in commercial III-V nitride based heterojunction light-emitting diodes. Stressing currents ranging from 100 mA to 200 mA were used. Degradations in the device properties were investigated through detailed studies of the I-V characteristics, electroluminescence, Deep-Level Transient Fourier Spectroscopy and flicker noise. Our experimental data demonstrated significant distortions in the I-V characteristics. The room temperature electroluminescence of the devices exhibited 25% decrement in the peak emission intensity. Concentration of the deep-levels was examined by measuring the Deep-Level Transient Fourier Spectroscopy, which indicated an increase in the density of deep-traps from 2.7 × 1013 cm−3 to 4.21 × 1013 cm−3 at E1 = EC − 1.1eV. The result is consistent with our study of 1/f noise, which exhibited up to three orders of magnitude increase in the voltage noise power spectra. Our experiments show large increase in both the interface traps and deep-levels resulted from hot-carrier stressing.

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25

MAKRA, P., Z. TOPALIAN, C. G. GRANQVIST, L. B. KISH y C. KWAN. "ACCURACY VERSUS SPEED IN FLUCTUATION-ENHANCED SENSING". Fluctuation and Noise Letters 11, n.º 02 (junio de 2012): 1250010. http://dx.doi.org/10.1142/s0219477512500101.

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Fluctuation-enhanced sensing (FES) comprises the analysis of the stochastic component of the sensor signal and the utilization of the microscopic dynamics of the interaction between the agent and the sensor. We study the relationship between the measurement time window and the statistical error of the measurement data in the simplest case, when the output is the mean-square value of the stochastic signal. This situation is relevant at any practical case when the time window is finite, for example, when a sampling of the output of a fluctuation-enhanced array takes place; or a single sensor's activation (temperature, etc.) is stepped up; or a single sensor's output is monitored by sampling subsequently in different frequency windows. Our study provides a lower limit of the relative error versus data window size with different types of power density spectra: white noise, 1/f(flicker, pink) noise, and 1/f2 (red) noise spectra.

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Malzac, Julien. "The emission of compact jets powered by internal shocks". Proceedings of the International Astronomical Union 8, S290 (agosto de 2012): 66–69. http://dx.doi.org/10.1017/s1743921312019229.

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AbstractThe emission of steady compact jets observed in the hard spectral state of X-ray binaries is likely to be powered by internal shocks caused by fluctuations of the outflow velocity. The dynamics of the internal shocks and the resulting spectral energy distribution (SED) of the jet is very sensitive to the shape of the Power Spectral Density (PSD) of the fluctuations of the jet Lorentz factor. I use Monte-Carlo simulations to investigate this dependence. It turns out that Lorentz factor fluctuations injected at the base of the jet with a flicker noise power spectrum (i.e. P(f) ∝ 1/f) naturally produce the canonical flat SED observed from radio to IR band in X-ray binary systems in the hard state. This model also predicts a strong, wavelength dependent, variability that resembles the observed one. In particular, strong sub-second variability is predicted in the infrared and optical bands.

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Smirnova, N., M. Hayakawa, K. Gotoh y D. Volobuev. "Scaling characteristics of ULF geomagnetic fields at the Guam seismoactive area and their dynamics in relation to the earthquake". Natural Hazards and Earth System Sciences 1, n.º 3 (30 de septiembre de 2001): 119–26. http://dx.doi.org/10.5194/nhess-1-119-2001.

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Abstract. The long-term evolution of scaling (fractal) characteristics of the ULF geomagnetic fields in the seismoactive region of the Guam Island is studied in relation to the strong (Ms = 8.0) nearby earthquake of 8 August 1993. The selected period covers 10 months before and 10 months after the earthquake. The FFT procedure, Burlaga-Klein approach and Higuchi method, have been applied to calculate the scaling exponents and fractal dimensions of the ULF time series. It is found that the spectrum of ULF emissions exhibits, on average, a power law behaviour S(f ) α f -b , which is a fingerprint of the typical fractal (self-affine) time series. The spectrum slope b fluctuates quasi-periodically during the course of time in a range of b = 2.5–0.7, which corresponds to the fractional Brownian motion with both persistent and antipersistent behaviour. An tendency is also found for the spectrum slope to decrease gradually when approaching the earthquake date. Such a tendency manifests itself at all local times, showing a gradual evolution of the structure of the ULF noise to a typical flicker noise structure in proximity to the large earthquake event. We suggest considering such a peculiarity as an earthquake precursory signature. One more effect related to the earthquake is revealed: the longest quasi-period, which is 27 days, disappeared from the variations of the ULF emission spectrum slope during the earthquake, and it reappeared three months after the event. Physical interpretation of the peculiarities revealed has been done on the basis of the SOC (self-organized criticality) concept.

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Burrage, Derek M., Joel C. Wesson, Mark A. Goodberlet y Jerry L. Miller. "Optimizing Performance of a Microwave Salinity Mapper: STARRS L-Band Radiometer Enhancements*". Journal of Atmospheric and Oceanic Technology 25, n.º 5 (1 de mayo de 2008): 776–93. http://dx.doi.org/10.1175/2007jtecho461.1.

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Abstract Airborne microwave radiometers for salinity remote sensing have advanced to a point where operational surveys can be conducted over the inner continental shelf to observe the evolution of freshwater plumes emanating from rivers and estuaries. To determine seawater microwave emissivity, and hence conductivity and salinity, precisely and accurately demands high instrument sensitivity, stability, and sampling rates; such requirements involve significant design trade-offs. The Salinity, Temperature, and Roughness Remote Scanner (STARRS) was developed to enhance these features relative to existing instruments. The authors describe here key elements of the STARRS design and the results of early performance assessments and deployments. During early deployments, the instrument performed well in areas of moderate to high salinity signal-to-noise ratio, but more homogenous areas revealed band-limited random signal fluctuations on the order of a 6-min period and ∼1-K amplitude that were of internal origin. Detailed analyses of laboratory and field tests revealed that internal “flicker,” or 1/f noise (having spectral roll-off proportional to the reciprocal of frequency f ), was the main source of these fluctuations. The instrument was modified to eliminate the random fluctuations and to further enhance sensitivity and stability. Laboratory tests and recent field deployments show that the upgrade improved instrument performance dramatically, to the extent that continental shelf scale areas with relatively homogenous salinity distributions can now be surveyed reliably using STARRS.

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Chai, Su-Young y Sung-Hoon Choa. "Reduction of Fluorine Diffusion and Improvement of Dark Current Using Carbon Implantation in CMOS Image Sensor". Crystals 11, n.º 9 (11 de septiembre de 2021): 1106. http://dx.doi.org/10.3390/cryst11091106.

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Recently, the demand of a high resolution complementary metal-oxide semiconductor (CMOS) image sensor is dramatically increasing. As the pixel size reduces to submicron, however, the quality of the sensor image decreases. In particular, the dark current can act as a large noise source resulting in reduction of the quality of the sensor image. Fluorine ion implantation was commonly used to improve the dark current by reducing the trap state density. However, the implanted fluorine diffused to the outside of the silicon surface and disappeared after annealing process. In this paper, we analyzed the effects of carbon implantation on the fluorine diffusion and the dark current characteristics of the CMOS image sensor. As the carbon was implanted with dose of 5.0 × 1014 and 1 × 1015 ions/cm2 in N+ area of FD region, the retained dose of fluorine was improved by more than 131% and 242%, respectively than no carbon implantation indicating that the higher concentration of the carbon implantation, the higher the retained dose of fluorine after annealing. As the retained fluorine concentration increased, the minority carriers of electrons or holes decreased by more Si-F bond formation, resulting in increasing the sheet resistance. When carbon was implanted with 1.0 × 1015 ions/cm2, the defective pixel, dark current, transient noise, and flicker were much improved by 25%, 9.4%, 1%, and 28%, respectively compared to no carbon implantation. Therefore, the diffusion of fluorine after annealing could be improved by the carbon implantation leading to improvement of the dark current characteristics.

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Steele, A. W. y G. M. Hieftje. "A Modulated Sample Introduction System for Atomic Emission Spectrometry". Applied Spectroscopy 40, n.º 3 (marzo de 1986): 357–63. http://dx.doi.org/10.1366/0003702864509240.

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A modulated sample-introduction device for use in flame emission spectrometry has been constructed and evaluated. With this device, the flow of aerosol to the excitation source is modulated by the application, at a specific frequency, of a pressure pulse to the nebulizer chamber; the use of frequency-selective detection then permits efficient signal recovery. If source background remains at a constant level, it is not detected and the signal-to-background ratio (S/B) is consequently improved. Because the technique provides a decrease in the instrument 1/f and flame-background flicker noise, detection limits are improved. These features are especially prominent when the analyte line of interest is in a spectral region of high source background. Modulation frequencies of 8 to 20 Hz have been explored and have resulted in good depth of modulation (>99%) and signal-pulse separation. The construction and operation of the device will be described and its performance for several elements evaluated in terms of detection limits, S/B enhancement, and working curve linearity. Also, the extension of the technique to selective spectralline modulation schemes and to inductively coupled plasma emission spectrometry will be considered.

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31

Malzac, Julien y Samia Drappeau. "Spectra and fast multi-wavelength variability of compact jets powered by internal shocks". Proceedings of the International Astronomical Union 10, S313 (septiembre de 2014): 159–63. http://dx.doi.org/10.1017/s1743921315002112.

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AbstractThe emission of steady compact jets observed in the hard spectral state of X-ray binaries is likely to be powered by internal shocks caused by fluctuations of the outflow velocity. The dynamics of the internal shocks and the resulting spectral energy distribution (SED) of the jet is very sensitive to the shape of the Power Spectral Density (PSD) of the fluctuations of the jet Lorentz factor. It turns out that Lorentz factor fluctuations injected at the base of the jet with a flicker noise power spectrum (i.e. P(f) ∝1/f) naturally produce the canonical flat SED observed from radio to IR band in X-ray binary systems in the hard state. This model also predicts a strong, wavelength dependent, variability that resembles the observed one. In particular, strong sub-second variability is predicted in the infrared and optical bands. The assumed fluctuations of the jet Lorentz factor are likely to be triggered by the variability of the accretion flow which is best traced by the X-ray emission. In the case of GX339-4 for which high quality and simultaneous multi-wavelength data are available, we performed simulations assuming that the fluctuation of the jet Lorentz factor have the same PSD as the observed X-ray PSD. The synthetic SED calculated under this assumption provides a remarkable match to the observed radio to IR SED. In this case the model also produces strong mid-infrared spectral variability that is comparable to that reported in this source.

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32

Dwivedi, Ravindra, John F. Knowles, Christopher Eastoe, Rebecca Minor, Nathan Abramson, Bhaskar Mitra, William E. Wright et al. "Ubiquitous Fractal Scaling and Filtering Behavior of Hydrologic Fluxes and Storages from A Mountain Headwater Catchment". Water 12, n.º 2 (24 de febrero de 2020): 613. http://dx.doi.org/10.3390/w12020613.

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We used the weighted wavelet method to perform spectral analysis of observed long-term precipitation, streamflow, actual evapotranspiration, and soil water storage at a sub-humid mountain catchment near Tucson, Arizona, USA. Fractal scaling in precipitation and the daily change in soil water storage occurred up to a period of 14 days and corresponded to the typical duration of relatively wet and dry intervals. In contrast, fractal scaling could be observed up to a period of 0.5 years in streamflow and actual evapotranspiration. By considering long-term observations of hydrologic fluxes and storages, we show that, in contrast to previous findings, the phase relationships between water balance components changed with component period and were not perfectly in or out of phase at all periods. Self-averaging behavior was apparent, but the temporal scales over which this behavior was applicable differed among the various water balance components. Conservative tracer analysis showed that this catchment acted as a fractal filter by transforming white noise in the precipitation input signal to a 1/f flicker in the streamflow output signal by means of both spatial and temporal subsurface advection and dispersion processes and soil wetting properties. This study provides an improved understanding of hydrological filtering behavior in mountain critical zones that are critical sources of water and ecosystem services throughout the world.

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33

Scalas, E., A. Ridi, M. Robello y A. Gliozzi. "Flicker noise in bilayer lipid membranes". Europhysics Letters (EPL) 43, n.º 1 (1 de julio de 1998): 101–6. http://dx.doi.org/10.1209/epl/i1998-00308-1.

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34

Ward, Lawrence y Priscilla Greenwood. "1/f noise". Scholarpedia 2, n.º 12 (2007): 1537. http://dx.doi.org/10.4249/scholarpedia.1537.

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35

Milotti, Edoardo. "Linear processes that produce 1/for flicker noise". Physical Review E 51, n.º 4 (1 de abril de 1995): 3087–103. http://dx.doi.org/10.1103/physreve.51.3087.

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36

Sulis, S., M. Lendl, S. Hofmeister, A. Veronig, L. Fossati, P. Cubillos y V. Van Grootel. "Mitigating flicker noise in high-precision photometry". Astronomy & Astrophysics 636 (abril de 2020): A70. http://dx.doi.org/10.1051/0004-6361/201937412.

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Context. In photometry, the short-timescale stellar variability (“flicker”), such as that caused by granulation and solar-like oscillations, can reach amplitudes comparable to the transit depth of Earth-sized planets and is correlated over the typical transit timescales. It can introduce systematic errors on the inferred planetary parameters when a small number of transits are observed. Aims. The objective of this paper is to characterize the statistical properties of the flicker noise and quantify its impact on the inferred transit parameters. Methods. We used the extensive solar observations obtained with SoHO/VIRGO to characterize flicker noise. We simulated realistic transits across the solar disk using SDO/HMI data and used these to obtain transit light curves, which we used to estimate the errors made on the transit parameters due to the presence of real solar noise. We make these light curves publicly available. To extend the study to a wider parameter range, we derived the properties of flicker noise using Kepler observations and studied their dependence on stellar parameters. Finally, we predicted the limiting stellar apparent magnitude for which the properties of the flicker noise can be extracted using high-precision CHEOPS and PLATO observations. Results. Stellar granulation is a stochastic colored noise, and is stationary with respect to the stellar magnetic cycle. Both the flicker correlation timescales and amplitudes increase with the stellar mass and radius. If these correlations are not taken into account when fitting for the parameters of transiting exoplanets, this can bias the inferred parameters. In particular, we find errors of up to 10% on the ratio between the planetary and stellar radius (Rp∕Rs) for an Earth-sized planet orbiting a Sun-like star. Conclusions. Flicker will significantly affect the inferred parameters of transits observed at high precision with CHEOPS and PLATO for F and G stars. Dedicated modeling strategies need to be developed to accurately characterize both the star and the transiting exoplanets.

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37

Zaklikiewicz, A. M. "1/f noise of avalanche noise". Solid-State Electronics 43, n.º 1 (enero de 1999): 11–15. http://dx.doi.org/10.1016/s0038-1101(98)00204-4.

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38

Canessa, E. y V. L. Nguen. "Stochastic Dynamics Crossover From 1/ƒ3 to Flicker Noise". physica status solidi (b) 175, n.º 2 (1 de febrero de 1993): 319–30. http://dx.doi.org/10.1002/pssb.2221750203.

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39

Hooge, F. N. "1/f noise sources". IEEE Transactions on Electron Devices 41, n.º 11 (1994): 1926–35. http://dx.doi.org/10.1109/16.333808.

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40

Ou, Jack y Pietro M. Ferreira. "A Unified Explanation of gm/ID-Based Noise Analysis". Journal of Circuits, Systems and Computers 24, n.º 01 (10 de noviembre de 2014): 1550010. http://dx.doi.org/10.1142/s0218126615500103.

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We present an unified explanation of the transconductance-to-drain current (gm/ID)-based noise analysis in this paper. We show that both thermal noise coefficient (γ) and device noise corner frequency (f co ) are dependent on the gm/ID of a transistor. We derive expressions to demonstrate the relationship between the normalized noise power spectral density technique and the technique based on γ and f co . We conclude this letter with examples to demonstrate the practical implication of our study. Our results show that while both techniques discussed in this letter can be used to compute noise numerically, using γ and f co to separate thermal noise from flicker noise provides additional insight for optimizing noise.

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41

Glukhova, N. V., V. I. Korsun y L. A. Pesotskaya. "ESTIMATION QUALITY WATER WITH USE METHODOLOGIES FLICKER-NOISE SPECTROSKOPY". Key title Zbìrnik naukovih pracʹ Odesʹkoï deržavnoï akademìï tehnìčnogo regulûvannâ ta âkostì -, n.º 1(1) (2012): 41–46. http://dx.doi.org/10.32684/2412-5288-2012-1-1-41-46.

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42

Hughes, B., N. G. Fernandez y J. M. Gladstone. "GaAs FET's with a flicker-noise corner below 1 MHz". IEEE Transactions on Electron Devices 34, n.º 4 (abril de 1987): 733–41. http://dx.doi.org/10.1109/t-ed.1987.22989.

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43

Mazloum, Jalil y Samad Sheikhaei. "1/f3 (Close-in) Phase Noise Reduction by Tail Transistor Flicker Noise Suppression Technique". Journal of Circuits, Systems and Computers 29, n.º 03 (20 de mayo de 2019): 2050035. http://dx.doi.org/10.1142/s0218126620500358.

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In this paper, a novel circuit method is proposed to reduce 1/f3 (close-in) phase noise in a cross-coupled LC Voltage Control Oscillator (VCO) by suppressing flicker noise power of the tail transistor. Using an added resistor between drain and gate of the tail transistor, that works as a negative feedback, the tail transistor flicker noise is suppressed, and therefore, the 1/f3 output phase noise is reduced by 5.7[Formula: see text]dB. Also, the added resistor helps in better tail current shaping for phase noise reduction. The proposed oscillator is designed in a 0.18[Formula: see text][Formula: see text]m CMOS technology with 1.8[Formula: see text]V supply and 3.6[Formula: see text]mW power consumption. Post-layout simulations predict a phase noise of [Formula: see text][Formula: see text]dBc/Hz for the proposed oscillator at 100[Formula: see text]KHz offset from 3.1[Formula: see text]GHz carrier frequency. Mathematical analysis is included in the paper for confirmation of the phase noise performance enhancement. The Figure of Merit (FOM) of the proposed oscillator is 188.3 and 190.6[Formula: see text]dBc/Hz at 100[Formula: see text]KHz and 1[Formula: see text]MHz offsets, respectively.

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44

Ninness, B. "Estimation of 1/f noise". IEEE Transactions on Information Theory 44, n.º 1 (1998): 32–46. http://dx.doi.org/10.1109/18.650986.

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45

Lowen, S. B. y M. C. Teich. "Generalised 1/f shot noise". Electronics Letters 25, n.º 16 (1989): 1072. http://dx.doi.org/10.1049/el:19890718.

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46

Spencer, R. R. y J. Grishaw. "Simplified 1/f noise calculations". Electronics Letters 27, n.º 4 (1991): 312. http://dx.doi.org/10.1049/el:19910197.

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47

WEST, BRUCE J. "NETWORKS AND 1/f NOISE". Fluctuation and Noise Letters 10, n.º 04 (diciembre de 2011): 515–31. http://dx.doi.org/10.1142/s0219477511000703.

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Complex networks form one of the most challenging areas of modern research overarching the traditional scientific disciplines. Of particular importance is the manner in which information is shuttled back and forth between such networks, and whether or not there exists general principles that guide the flow of information. Herein, we identify Wiener's rule, which conjectures how information is transfered in an information-dominated process. Moreover, we show that this rule is a consequence of the Principle of Complexity Management (PCM) that determines the information exchange between complex networks. A consequence of the PCM is that the maximum information transfer occurs at a 1/f noise resonance. The information transfer between two complex networks is also determined by direct numerical calculation of a master equation model of network dynamics using interacting two-state elements, the decision-making model (DMM). The DMM generates phase transitions and on a two-dimensional lattice, reduces to the Ising model in an appropriate limit. The computations using the DMM suggest that the inverse power laws of links and survival probability are not necessarily related.

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48

Degerli, Y., F. Lavernhe, P. Magnan y J. Farré. "Bandlimited 1/f-noise source". Electronics Letters 35, n.º 7 (1999): 521. http://dx.doi.org/10.1049/el:19990417.

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49

van der Ziel, A. "Unified presentation of 1/f noise in electron devices: fundamental 1/f noise sources". Proceedings of the IEEE 76, n.º 3 (marzo de 1988): 233–58. http://dx.doi.org/10.1109/5.4401.

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50

Raninen, A. N. y J. Rovamo. "Flicker Sensitivity as a Function of Eccentricity". Perception 26, n.º 1_suppl (agosto de 1997): 327. http://dx.doi.org/10.1068/v970357.

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We determined DeLange curves with and without external temporal noise at eccentricities of 0 – 70 deg by measuring flicker sensitivity at 1 – 45 Hz for sharp-edged M-scaled spots with an equiluminous surround. Without noise, flicker sensitivity at high frequencies increased with eccentricity but remained unchanged at low frequencies. In strong noise, flicker sensitivity was independent of eccentricity. The only exception was 70 deg where sensitivity was reduced at 1 – 3 Hz with and without noise. The data at each eccentricity are well described by our flicker-sensitivity model (Rovamo et al, 1996 Vision Research36 3767 – 3774) comprising (i) low-pass filtering by the modulation transfer function (MTF) of the retina, (ii) filtering in direct proportion to temporal frequency by the high-pass MTF of the retina and subsequent neural visual pathways, (iii) addition of white internal neural noise, and (iv) detection by a temporal matched filter. When interpreted in the context of the model, our results mean that while the high-pass filter and the magnitude of internal noise remained unchanged across eccentricities, the bandwith of the low-pass filter increased with eccentricity and at 70 deg eccentricity the efficiency of the detecting mechanism in the brain was reduced at 1 – 3 Hz. The increase in the bandwidth of the low-pass filter is in agreement with the eccentricity-dependent changes in the retinal function as revealed by the electroretinogram (ERG).

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