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The article discusses the importance of understanding brain functional organization during human development through Precision Functional Mapping. It explores the use of multi-echo data acquisition and thermal noise removal techniques to improve data quality in precision fMRI studies with adults, children, and newborn infants. The research highlights the potential benefits of these methods in enhancing functional connectivity matrices and signal-to-noise ratios, particularly in developmental populations, while also emphasizing the need for further investigation into their application in infants. [Extracted from the article]

We analyze the impact of Lévy-distributed stochastic fluctuations on the average switching time and voltage drop across a current-biased long Josephson tunnel junction. We compare the system's response for two spatial configurations of time-dependent noise, i.e. , homogeneous and distributed along the junction length. The response of the Josephson junction is explored by varying the characteristic parameter of the Lévy source, i.e. , the α stability index and the noise intensity. These findings offer an effective tool to characterize a Lévy component possibly embedded in an unknown noise signal. • Analyzed impact of Lévy-distributed noise on switching time and voltage in Josephson junctions. • Explored effects of homogeneous vs. spatially distributed Lévy noise configurations. • Identified distinct behaviors in superconducting lifetime and voltage drop with varying noise. • Highlighted potential applications of Josephson junctions as detectors for non-Gaussian noise. • Identified regimes where thermal noise does not mask Lévy noise effects in Josephson junctions. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the adaptive target detection problem for a collocated frequency diverse array multiple-input multiple-output (FDA-MIMO) radar in the presence of mainlobe deceptive jamming and partially homogeneous noise with an unknown covariance matrix and scaling factor. Precisely, we establish a received signal model that includes the true target and false counterparts echoes in the presence of Gaussian noise (it includes thermal noise, interference suppression, and clutter after range compensation.). Furthermore, we consider that the range information of the true target and mainlobe deceptive targets is not identical. Therefore, we project the corresponding transmit steering vectors onto different subspaces with known subspace matrices but unknown coordinates. On the other hand, the true and false targets' receive steering vectors are considered to be from the same subspace. Finally, following the generalized likelihood ratio test (GLRT), the Rao and the Wald criteria, we design three adaptive detectors with two-step criteria, i.e., TGLRT, TRao, and TWald. We note that the proposed detectors maintain a constant false alarm rate (CFAR) against the scaling factor and the noise covariance matrix. The extensive numerical simulation results have validated the effectiveness of the proposed detectors. [ABSTRACT FROM AUTHOR]

In this paper, for the first time, the phase noise analysis of a Multi-loop Skew based Single Ended Oscillator (MSSROs) is derived and validated. Compared to the three stages of conventional ring oscillators (CROs), SDROs provide an equivalent oscillation frequency with improved phase noise with increasing stages. The primary distinction between these two designs (SDRO and three-stage CROs) is the inherent skew offset between the PMOS/NMOS gates caused by the unique connection. This skew offset is the fundamental cause of delay cell noise suppression; the SDROs have loosely coupled oscillators that run concurrently, forming multiple 3-stages of separately driven Ring Oscillators. As a result, a shaping function is derived in terms of skew offset, and simulating these with varying skew offset results in suppressing behavior. Additionally, we derived phase noise for a skew-based design and validated it in PDKs of 180nm and 65 nm. We plotted the thermal (flicker) noise contribution and found that increasing the number of stages leads to an approximately 1-2 dB reduction in phase noise while maintaining the same NMOS/PMOS size ratio. Finally, a 2-3 dB reduction in phase noise is achieved in MSSROs by incorporating the shaping function into phase noise equations. [ABSTRACT FROM AUTHOR]

In this paper, we present an integrator-differentiator transimpedance amplifier (I-D-TIA) with a dc compensation, which incorporates widely tunable multi-element pseudo-resistors (MEPRs) in its dc servo loop and ac signal path. The implemented MEPR in the dc path is continuously tunable from $460 \,\mathrm {k\Omega }$ to $300 \,\mathrm {G\Omega }$ allowing the TIA to process dc currents with a dynamic range of more than $100 \,\mathrm {dB}$. The MEPR in the differentiator ac signal path provides a tunable resistance between $0.3 \,\mathrm {M\Omega }$ and $100 \,\mathrm {M\Omega }$ , resulting in an overall ac transimpedance between $3 \,\mathrm {M\Omega }$ and $1 \,\mathrm {G\Omega }$. For the lowest ac transimpedance, a bandwidth of $10 \,\mathrm {MHz}$ is achieved. The TIA provides a minimum input-referred current noise density of $1.6\,\mathrm {fA}/\mathrm {\sqrt {Hz}}$. The implemented MEPR has been optimized regarding its high-frequency noise by minimizing its parasitic capacitances. The MEPR shows an inherent shot noise suppression such that its noise stays close to the theoretical thermal noise limit and significantly below the theoretical shot noise limit, even for large dc currents. By using a sub-VSS supply for the MEPR, the asymmetry in its output characteristic is greatly reduced, leading to a linear signal swing of $1.5\,\mathrm {V_{pp}}$ with a THD below $1 \mathrm {\%}$ on a $1.8-\mathrm {V}$ supply. Thanks to this high linearity, large bandwidth, and high dc current dynamic range, the proposed TIA can be used in a wide variety of applications from high-sensitivity, low-bandwidth lock-in detection to transient current sensing with sub-microsecond timing resolutions. [ABSTRACT FROM AUTHOR]

In this paper, we present a reconfigurable Physically Unclonable Functions (PUF) based on the Spin-Orbit-Torque Magnetic Random-Access Memory (SOT-MRAM), which exploits thermal noise as the true dynamic entropy source. Therefore, the MRAM cells could be configured to random final states with stochastic switching mechanism. The proposed PUF is constructed and reconfigured by combining the small-capacity true random number generator (TRNG) and high-reliability secure hash algorithm (SHA-512), realizing the dynamic transformation between SOT-MRAM based last level cache and PUF (In-Cache-MPUF). Thanks to the full reconfigurability and the high endurance of SOT-MRAM, the proposed In-Cache-MPUF can achieve $10^{\textbf {14}}$ maximum PUF bits per cell, which has greatly motivated the implementations compared with the traditional weak PUFs utilizing the static entropy source of process variations. The Monte-Carlo simulation results using 40 nm technology and a compact MTJ model show that the proposed PUF has desirable randomness as the digitized bit streams passing all the NIST tests, achieving 50.0428% uniqueness as well as 49.9236% uniformity. It also shows comparable reliability to the state-of-the-art works: a maximum bit error rate of 0.14% and 0.12% at 100 °C and 0.9 V, respectively. In addition, the system level performance is tested and validated by gem5. [ABSTRACT FROM AUTHOR]

Problems involving discrete Markov Chains are solved mathematically using matrix methods. Recently, several research groups have demonstrated that matrix-vector multiplication can be performed analytically in a single time step with an electronic circuit that incorporates an open-loop memristor crossbar that is effectively a resistive random-access memory. Ielmini and co-workers have taken this a step further by demonstrating that linear algebraic systems can also be solved in a single time step using similar hardware with feedback. These two approaches can both be applied to Markov chains, in the first case using matrix-vector multiplication to compute successive updates to a discrete Markov process and in the second directly calculating the stationary distribution by solving a constrained eigenvector problem. We present circuit models for open-loop and feedback configurations, and perform detailed analyses that include memristor programming errors, thermal noise sources and element nonidealities in realistic circuit simulations to determine both the precision and accuracy of the analog solutions. We provide mathematical tools to formally describe the trade-offs in the circuit model between power consumption and the magnitude of errors. We compare the two approaches by analyzing Markov chains that lead to two different types of matrices, essentially random and ill-conditioned, and observe that ill-conditioned matrices suffer from significantly larger errors. We compare our analog results to those from digital computations and find a significant power efficiency advantage for the crossbar approach for similar precision results. [ABSTRACT FROM AUTHOR]

This paper investigates an ultra-broadband sampling technique based on charge sampling using an Integrate-and-Hold Circuit (IHC) and ultra-short integration times. The charge sampling technique is mathematically analyzed in detail and compared to conventional switched-capacitor sampling. The mathematical analysis allows to predict the sampler bandwidth as well as the degradation of sampling precision due to analog circuit impairments such as integrator gain error, integration capacitor leakage, hold-mode droop, thermal noise, and clock jitter. Furthermore, design, simulation, and measurement results of an ultra-broadband charge sampler IC in SiGe BiCMOS technology are presented. The charge sampler IC achieves a 1dB bandwidth of 70 GHz. A resolution of better than 5.9 effective number of bits (ENOB) is measured from 0 to 70 GHz at a sampling rate of 5 GS/s. The results suggest that charge sampling using an IHC is a viable concept for ultra-broadband sampling. [ABSTRACT FROM AUTHOR]

Power consumption is an important limitation in designing analog-to-digital converters (ADCs) used in low-power sensing applications. This paper estimates analytically the power bound of a two-step multi-stage noise-shaping successive-approximation-register incremental ADC (two-step MASH NS-SAR IADC) proposed in our previous work. Our model considers the impacts of thermal noise, mismatch, and CMOS process (minimum feature size in CMOS technologies) on the power bounds of the proposed IADC. The analytic results show that thermal noise and CMOS process requirements determine the power consumption lower bounds in high and low resolutions, respectively. A comparison with the most competitive single-loop delta-sigma (ΔΣ) IADC shows a 3-dB higher theoretical figure-of-merit (FoM) for our proposed IADC when the resolutions are higher than 12-bit. Our proposed systematic analysis can be used to estimate the power bounds of amplifier-based NS-SAR ADCs used in either ΔΣ or incremental mode with multi-stage and multi-step topologies designed in various CMOS technologies. The reported analytic results are confirmed by experimental results of previously reported implementations. [ABSTRACT FROM AUTHOR]

A study conducted by researchers at Kurdistan University in Iran investigated the immediate effects of combined exposure to heat and noise on human brain waves and perceived workload. The study involved 72 student participants who were exposed to varying levels of noise and heat for 30 minutes each. The results showed that high levels of combined noise and heat led to an increase in perceived mental workload and changes in brain wave activity. The findings suggest that these changes can serve as indicators of cognitive and physiological performance. The study provides insights into the health hazards of industrial environments in Iran and highlights the need for further research in this area. [Extracted from the article]

The article focuses on Piave Refrigeration's evolution as a one-stop shop for high-quality heating and ventilation parts and engineering services for bus and coach systems. Topics include the company's growth from a small beginning to a boutique parts supplier, its specialization in designing heat exchangers and innovative replacement coil designs, and its expansion as an agent for Johnson boost pumps and Konvekta AG providing technical support.

A millimeter-wave current-reuse voltage-controlled oscillator (VCO) features a single-turn multi-tap inductor and two separate differential-only switched-capacitor arrays to improve the power efficiency and phase noise (PN). Specifically, a single-branch complementary VCO topology, in conjunction with a multi-resonant Resistor-Inductor-Capacitor-Mutual inductance (RLCM) tank, allows sharing the bias current and reshaping the impulse-sensitivity-function. The latter is based on an area- efficient RLCM tank to concurrently generate two high quality- factor differential-mode resonances at the fundamental and 2nd- harmonic oscillation frequencies. Fabricated in 65-nm CMOS technology, our VCO at 27.7 GHz shows a PN of −109.91-dBc/Hz at 1-MHz offset (after on-chip divider-by-2), while consuming just 3.3 mW at a 1.1-V supply. It corresponds to a Figure-of-Merit (FOM) of 187.6 dBc/Hz. The frequency tuning range is 15.3% (25.2 to 29.4 GHz) and the core area is 0.116 mm2. [ABSTRACT FROM AUTHOR]

This paper presents a nonlinear digital decoder (reconstruction filter) for incremental delta-sigma modulators. This decoder utilizes both the magnitude and pattern information of the modulator output to achieve accurate input estimation. Compared to the conventional linear filters with the same oversampling ratio (OSR), it can improve the converter’s signal-to-quantization noise ratio by a few dB to a few 10’s of dB with slight thermal noise performance degradation. Using the proposed decoder, the modulator’s OSR can be a few times less while achieving the same resolution and data rate, thus minimizing the modulator as well as its peripheral circuits’ energy consumption. In this paper, the proposed decoder is optimized for digital implementation, with its function being verified using a modulator prototype. This decoder is mainly designed for dc or near-dc signal conversions and it does not provide frequency notches. [ABSTRACT FROM AUTHOR]

In this work we propose a single channel band-pass (BP) SAR ADC with dynamic noise transfer function (NTF) re-configuration. The proposed ADC employs a low-power two-stage architecture. After the SAR finishes quantization, the residue is extracted by firing the comparator multiple times. An estimate of the residue is obtained by employing a maximum likelihood based estimator (MLE). The output of the ADC is obtained by subtracting a delayed version of the estimated residue from the SAR output thus generating a complex NTF with multiple notches in the spectrum. A 65nm ADC prototype achieves 74.1/78dB SNDR/DR over a 101.2kHz bandwidth while consuming 17 μW from a 1V supply at 2.43MS/s. The ADC core occupies an area of 0.12mm2. The ADC achieves 8fJ/c-step bandpass FoM which is 85 × better than state-of-the-art BP ADCs with similar bandwidth and 8.7 × better than all reported state-of-the-art BP ADCs. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to describe and investigate the mathematical models and numerical modeling of how a cell membrane is affected by a transient ice freezing front combined with the influence of thermal fluctuations and anisotropy. Design/methodology/approach: The study consists of mathematical modeling, validation with an analytical solution, and shows the influence of thermal noises on phase front dynamics and how it influences the freezing process of a single red blood cell. The numerical calculation has been modeled in the framework of the phase field method with a Cahn–Hilliard formulation of a free energy functional. Findings: The results show an influence scale on directional phase front propagation dynamics and how significant are stochastic thermal noises in micro-scale freezing. Originality/value: The numerical calculation has modeled in the framework of the phase field method with a Cahn–Hilliard formulation of a free energy functional. [ABSTRACT FROM AUTHOR]

This paper presents a multirate predictive successive approximation register (SAR) analog-to-digital converter (ADC). The main objective is to introduce digital frameworks for resolving the weaknesses of the previous predictive schemes in the context of the SAR ADC. The proposed SAR ADC compensates for the capacitive element mismatches, extends the input signal frequency using an adaptive digital predictive machine (ADPM), and relaxes the speed requirement through multirate implementation of the ADPM. As a consequence, the achievable sampling-rate can also be improved by optimizing the capacitors according to the thermal noise requirement. Behavioral simulation results, based on the Monte Carlo method, are provided for a 12-bit SAR ADC to verify the usefulness of the proposed approach. The simulation results indicate that the means of the spurious-free dynamic range (SFDR) and the signal-to-noise and distortion ratio (SNDR) are 82.3 and 69.1 dB, respectively. [ABSTRACT FROM AUTHOR]

While there had been speculation that AMD would go with an eight-channel memory configuration to coincide with an expected 64-core CPU, AMD didn't say peep about additional memory channel support (which would require an additional new platform) or a new CPU. Of course, from AMD's point of view, it probably thinks Core i9 can't even hang with its Thread-ripper anymore and would rather see its $750 16-core Ryzen 9 3950X duke it out with Core i9 today. [Extracted from the article]

The article informs about Oxford Cryosystems' evolution from a laboratory project in the 1980s to a global provider of cryogenic solutions, with their Gifford McMahon (GM) coldheads becoming integral components in various applications worldwide. Topic include Oxford Cryosystems plans to expand its range with new single-stage and two-stage coldheads, along with advanced helium compressors, marking the beginning of a new phase of innovation and expansion for the company.

In this work, we investigate the active dynamics and ergodicity breaking of a nonequilibrium fractional Langevin equation (FLE) with a power-law memory kernel of the form K (t) ∼ t − (2 − 2 H) , where 1 / 2 < H < 1 represents the Hurst exponent. The system is subjected to two distinct noises: a thermal noise satisfying the fluctuation–dissipation theorem and an active noise characterized by an active Ornstein–Uhlenbeck process with a propulsion memory time τ A. We provide analytic solutions for the underdamped active fractional Langevin equation, performing both analytical and computational investigations of dynamic observables such as velocity autocorrelation, the two-time position correlation, ensemble- and time-averaged mean-squared displacements (MSDs), and ergodicity-breaking parameters. Our results reveal that the interplay between the active noise and long-time viscoelastic memory effect leads to unusual and complex nonequilibrium dynamics in the active FLE systems. Furthermore, the active FLE displays a new type of discrepancy between ensemble- and time-averaged observables. The active component of the system exhibits ultraweak ergodicity breaking where both ensemble- and time-averaged MSDs have the same functional form with unequal amplitudes. However, the combined dynamics of the active and thermal components of the active FLE system are eventually ergodic in the infinite-time limit. Intriguingly, the system has a long-standing ergodicity-breaking state before recovering the ergodicity. This apparent ergodicity-breaking state becomes exceptionally long-lived as H → 1 , making it difficult to observe ergodicity within practical measurement times. Our findings provide insight into related problems, such as the transport dynamics for self-propelled particles in crowded or polymeric media. • First analytic and numerical study for underdamped active fractional Langevin equations. • Active FLEs perform superballistic underdamped dynamics via the viscoelastic feedback. • Activity-induced super- and sub-diffusive dynamics emerge in the overdamped regime. • Time-averaged MSDs are inequivalent with ensemble-averaged MSDs (ergodicity breaking). • Viscoelasticity is critical to duration and degree of the ergodicity breaking state. [ABSTRACT FROM AUTHOR]

RGBW (RGB-White) CFAs (Color Filter Arrays) which contain white pixels as well as RGB pixels have been actively proposed, which is due to the higher SNR (Signal to Noise Ratio) characteristics of the white pixels. The higher SNR characteristics of the white pixels results in the reconstruction of color images with higher resolutions than those reconstructed with widely used RGB CFAs, especially in low illumination environments. Recently, we proposed a new RGBW demosaicking method which uses an RGBW CFA where the white pixels cover 75% of the CFA, and which reconstructs the color image from the RGBW pattern image by use of the colorization method. The use of a large number of white pixels, and the use of colorization as an interpolation method made it possible to reconstruct a color image with high SNR values. In this paper, we extend this method to reconstruct video sequences by extending the colorization method to the 3-D domain, i.e., we propose a 3-D color reconstruction method which takes an RGBW pattern video sequence as the input and produces a reconstructed color video sequence. We implement the colorization as a 3-D diffusion instead of solving an overall colorization matrix, since the computation is high for the 3-D domain. The 3-D diffusion flow stops at temporal edges, which prevents the false colorizing of moving objects. Furthermore, the 3-D diffusion flow also eliminates the incoherence between colors of neighboring frames, which eliminates the flickering artifact. One major difficulty in extending to the temporal axis is that the noise in the few color seeds can propagate throughout the 3-D domain resulting in many false colors. This is especially important in the case when the image/video is taken in low illumination, since the energy of the thermal noise becomes relatively large compared to the light energy making the RGBW pattern image/video very noisy. To prevent the propagation of false colors caused by the noise in the color seeds, we use the 3-D stacked white channels as a guidance for denoising, so that the denoising takes into account only the color seeds that belong to the same object region in the 3-D space. The stacked white channels also guide the 3-D diffusion throughout the 3-D space. Experimental results show that the image/video reconstructed by the proposed method has better visual quality than those reconstructed by conventional RGB/RGBW CFA based methods. Therefore, the proposed method can be used in surveillance camera applications to recover important information from noisy video sequences taken in very low illumination environment. [ABSTRACT FROM AUTHOR]

In the design of sigma-delta modulators ($\Sigma \Delta $ Ms), different variables need to be optimized together in order to maximize the performance. This design task has the added difficulty of dealing with the non-linear behavior of the quantizer. Although a linearized model of the quantizer can be used, this may result in significant discrepancies between the predicted and actual behavior of the $\Sigma \Delta \text{M}$. To better predict the behavior of a given design, we propose a design methodology for $\Sigma \Delta $ Ms based on a genetic algorithm (GA) that uses both linear equations and simulations. In order to reduce the computation time, the design solution is initially evaluated using equations and only if the performance is deemed good enough, it is subjected to a more refined simulation. This more precise simulation takes into account thermal noise, finite output swing, and gain (among other non-idealities) of the building blocks of the modulator. Moreover, Monte Carlo (MC) analyses are performed during the optimization in order to assess the sensitivity to component variations of the solutions. In order to demonstrate the validity and robustness of the proposed optimization methodology, several $\Sigma \Delta $ Ms designs are presented, together with the corresponding measured results. [ABSTRACT FROM AUTHOR]

A pipeline analog-to-digital converter (ADC) with high power efficiency is implemented in this paper. The ADC architecture consists of 3.5b, 3.5b, 3.5b, and 4b sub-ADCs. For the first three stages, a current-reuse technique is employed in the current mode multiplying digital-to-analog converters (MDACs). An operational transconductance amplifier (OTA) converts an input voltage into current; A current-steering DAC reuses the OTA bias current. The OTA and the DAC generate the sub-ADC residue in a current domain. As a result, both power consumption and thermal noise for the MDAC are reduced. A transimpedance amplifier (TIA) with a feedback resistor is utilized to convert the current signal to a voltage residue signal for the next stage. An off-chip calibration scheme is used to correct interstage gain and nonlinearity errors. The fabricated ADC achieves 68.1 dB signal-to-noise-and-distortion ratio (SNDR) and 82.3 dB spurious free dynamic range (SFDR) for a sinusoidal input at 4.17 MHz. The ADC operates at a maximum sampling frequency of 260 MHz. With an input signal at 123.129 MHz, the measured SNDR/SFDR are 66.3/78.22 dB, respectively. The total power consumption for the ADC running at maximum speed is 15.38 mW. Thus, the pipeline ADC achieves a 167.4 dB figure-of-merit (FoM). The chip was manufactured in a TSMC 40-nm CMOS process. [ABSTRACT FROM AUTHOR]

The problem of detecting a subspace signal embedded in subspace Gaussian interference and thermal noise is studied in this paper. In this problem, both the signal-independent and signal-dependent interferences are assumed to be present, therefore the overall interference subspace covers the signal subspace. The approach of this paper extends previous works involving either of those two kinds of interferences. A set of secondary data containing only interference plus noise is employed to estimate the interference covariance matrix and the noise power. Three new detectors are designed via the generalized likelihood ratio (GLR), Rao and Wald tests, respectively. Their probabilities of false alarms (PFAs) and detections are analytically derived. The PFAs show that the new detectors have the constant false alarm rate (CFAR) property against the interference and noise. Numerical results show that the new detectors outperform their counterparts for the studied problem. Furthermore, the new detectors are less sensitive to the secondary data size and to the mismatched subspace signal than some other detectors, such as the GLR detector (GLRD), the adaptive matched filter (AMF), the adaptive subspace detector (ASD), etc. [ABSTRACT FROM AUTHOR]

This paper presents an analytical method for the performance evaluation of the correlation-based impulse radio (IR) receivers, which detect the data based on synchronizing the received signal with a locally generated template pulse. In this paper, a phase interpolation technique is employed to preserve synchronization accuracy with low power consumption. The analytical method computes the spectral density of jitter at the phase interpolator output, resulting from both flicker and thermal noise components. The analysis considers the aliasing phenomenon due to the sampling of the noise to predict the induced jitter accurately. Bit error rate (BER) of the receiver is also statistically estimated in terms of the induced jitter on the template pulse, the noise effect of the receiver chain, and the template signal level. The proposed estimation procedure is validated by comparing its results with transient noise simulations. It is shown that increasing the template signal range in the correlator and improving the linearity of the phase interpolation transfer curve, at a given power consumption, enhances the receiver sensitivity by 2 and 3.5 dB, respectively. The BER estimation results also reveal that the effect of the template signal jitter on the sensitivity of the correlation-based IR receivers becomes dominant with the increasing input signal level. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of adaptive detection of a range-spread target in colored Gaussian disturbance. The range-spread target is described by a multi-rank subspace model, which lies in a subspace but with unknown coordinates. The disturbance, usually including clutter and thermal noise, has an unknown covariance matrix. Under the above assumption, we design the Rao and generalized likelihood ratio test (GLRT) detectors by the two-step procedure, which incorporates persymmetric structure of received data. The two detectors are shown to coincide with each other. Remarkably, the proposed detector ensures constant false alarm rate property. Experimental results conducted by both simulation and real data verify that the proposed detector outperforms the existing counterparts in training-limited scenarios. [ABSTRACT FROM AUTHOR]

Incremental analog-to-digital-converters (IADCs) are variants of $\triangle \Sigma $ ADCs, which have been increasingly used for low-power sensory applications in recent years. Most IADC applications require high resolution and high energy efficiency. In this paper, we present a systematic analysis of IADCs. We derive analytical design equations for practical IADC designs. Process limitations are included in the model as well. The equations are verified with a 14-bit second-order IADC design in a 0.18- $\mu \text{m}$ process. With the design equations, the theoretical energy efficiency bound is derived for IADCs. The efficiency bound is compared with previously reported IADC designs. It is found that the derived bound matches existing designs well. [ABSTRACT FROM AUTHOR]

This article discusses the challenges and potential advancements in precision functional magnetic resonance imaging (fMRI) for studying brain development in infants. The researchers explore the use of multi-echo (ME) data acquisition and thermal noise reduction techniques in fMRI data from three newborn infants. They find that ME acquisition shows promise in optimizing developmental fMRI, and the application of thermal denoising improves the strength of functional connections in infant data. However, further investigation is needed to fully understand the best techniques for developmental brain imaging. This preprint has not yet undergone peer review. [Extracted from the article]

A novel switched-capacitor low-pass filter architecture is presented. In the proposed scheme, a feedback path is added to a charge-rotating real-pole filter to implement complex poles. The selectivity is enhanced, and the in-band loss is reduced compared with the real-pole filter. The output thermal noise level and the tuning range are both close to those of the real-pole filter. These features make the filter suitable for high speed, low noise, and low power applications. A fourth-order filter prototype was implemented in a 180-nm CMOS technology. The measured in-band loss is reduced by 3.3 dB compared with that of a real-pole filter. The sampling rate of the filter is programmable from 65 to 300 MS/s with a constant dc gain. The 3-dB cut-off frequency of the filter can be tuned from 490 to 13.3 MHz with over 100-dB maximum stop-band rejection. The measured in-band third-order output intercept point is 28.7 dBm, and the averaged spot noise is 6.54 nV/ $\surd $ Hz. The filter consumes 4.3 mW from a 1.8 V supply. [ABSTRACT FROM AUTHOR]

A unique readout circuit topology aimed at integration with a novel type of magnetic random access memory (MRAM) is presented. The properties of the new MRAM bitcell are introduced, and the specifics of the circuit used to interface with the CMOS circuitry are described. The noise transfer function and effectiveness of the proposed topology with its practical limitations are discussed. Post-silicon measurement results verify the validity of this topology. Integration of the proposed readout circuit with the MRAM bitcells is discussed. Measurement results show an integrated input noise of $89~\mu $ Vrms, and reliable sensing of signal level of 1 mV. [ABSTRACT FROM AUTHOR]

Magnetic skyrmions are topological solitons and have great potential applications in next-generation spintronic devices for information storage and processing technologies. Here, we present an approach using the master equation involving the thermal noise to obtain the dynamical evolution of the skyrmion breathing based on the three-magnon scattering in a magnetic film, and develop a two-step model to obtain the approximated analytic solution. We show that the skyrmion breathing experiences a process where the thermal noise competes with the time-varying gain in the step I. Then the excited magnon number of the skyrmion breathing mode undergoes exponential growth with the evolutionary time due to the generation of negative total damping rate induced by the microwave drive field in the step II, which is referred to as coherent stimulated amplification of the skyrmion breathing. The analytic result is shown to be in good agreement with numerical calculation. We also obtain the threshold power of the coherent stimulated amplification behavior. In addition to offering insight into the nonlinear dynamics of skyrmions, potential applications range from realizing skyrmion cooling to providing excitation source for PT -symmetric skyrmionic systems. [ABSTRACT FROM AUTHOR]

A complete framework for exciting and detecting thermally-induced, stabilized sine-Gordon breathers in ac-driven annular long Josephson junctions is developed. The formation of long-time stable breathers locked to the ac source occurs for a sufficiently high temperature. The latter emerges as a powerful control parameter, allowing for the remarkably stable localized modes to appear. Nonmonotonic behaviors of both the breather generation probability and the energy spatial correlations versus the thermal noise strength are found. The junction's resistive switching characteristics provides a clear experimental signature of the breather. • Long Josephson junctions are studied in the presence of ac-driving and thermal noise. • Remarkably stable sine-Gordon breathers emerge for a sufficiently high temperature. • The breather generation probability is a nonmonotonic function of the noise strength. • The energy spatial correlations behave nonmonotonically vs. the noise intensity. • Breathers induce peculiar oscillations into the junction's switching characteristics. [ABSTRACT FROM AUTHOR]

Quantum-based experiments and their applications in lasers and magnetic fields have long been paramount, yet how to achieve exact stability for a long time is a merely answered question. This article develops a coupled laser map with cavity loss via a one-dimensional laser map, where complex phenomena in the newly developed mathematical model, dynamical properties with coupling delay, and thermal fluctuation of the lasing system are discussed numerically and analytically. It is deduced that the intensity of the laser beam can be controlled and stabilized for a long time, and large values of the effective gain coefficient can be reached when thermal noise exists in the optical cavity and when a nonlinear feedback loop is provided with coupling delay. Utilizing noise and coupling delay as a nonlinear feedback loop to the coupled laser map, we observed non-autonomous behaviour at different growth rate values. In contrast, symmetrical and phase-entrained synchronized mirror imaged orthogonal strange attractors and fractals were seen at the same growth rate values. At specific values of the controlling parameters, the peculiar attractors experience cyclic collisions with their basin boundaries, which break symmetry and synchronization and cause irregular behaviour. [ABSTRACT FROM AUTHOR]

The emergence of traveling sine-Gordon breathers due to the nonlinear supratransmission effect is theoretically studied in a long Josephson junction driven by suitable magnetic pulses, taking into account the presence of dissipation, a current bias, and a thermal noise source. The simulations clearly indicate that, depending on the pulse's shape and the values of the main system parameters, such a configuration can effectively yield breather excitations only. Furthermore, a nonmonotonic behavior of the breather-only generation probability is observed as a function of the noise intensity. Finally, the dynamics of the supratransmission-induced breathers is characterized by looking at quantities such as their radiative decay lifetime and the medium's energy. • Supratransmission-induced breathers are studied in a driven long Josephson junction. • Both phase-based and voltage-based breather detection criteria are introduced. • A positive noise-induced effect on the examined generation process is found. • The breather lifetime and the medium's energy are used to analyze the mode's dynamics. • A significant degree of robustness of the breather to thermal fluctuations emerges. [ABSTRACT FROM AUTHOR]

The aim of this work is to provide an improved information exchange in hierarchical atomistic-to-continuum settings by applying stochastic approximation methods. For this purpose a typical model belonging to this class is chosen and enhanced. On the macroscale of this particular two-scale model, the balance equations of continuum mechanics are solved using a nonlinear finite element formulation. The microscale, on which a canonical ensemble of statistical mechanics is simulated using molecular dynamics, replaces a classic material formulation. The constitutive behavior is computed on the microscale by computing time averages. However, these time averages are thermal noise-corrupted as the microscale may practically not be tracked for a sufficiently long period of time due to limited computational resources. This noise prevents the model from a classical convergence behavior and creates a setting that shows remarkable resemblance to iteration schemes known from stochastic approximation. This resemblance justifies the use of two averaging strategies known to improve the convergence behavior in stochastic approximation schemes under certain, fairly general, conditions. To demonstrate the effectiveness of the proposed strategies, three numerical examples are studied. [ABSTRACT FROM AUTHOR]

Aiming at the deterioration issue of amplitude-locked superfluid gyro system measurement accuracy and stability caused by temperature rise delay and thermal noise in the process of hot phase injection, a method for amplitude-locked superfluid gyroscope control system design based on fuzzy active disturbance rejection is proposed in this paper. Firstly, the mathematical model of superfluid gyroscope is established. The mechanism of effect of temperature rise delay and unknown thermal noise on system measurement accuracy and stability is analyzed. Secondly, a fuzzy active disturbance rejection controller, including differential tracker, extended state observation and nonlinear feedback control law is presented. Furthermore fuzzy reasoning is employed to realize the adaptive adjustment of proportional and differential coefficients in the nonlinear combination. Finally, the control method is verified by use of Maltlab/Simulink. Simulation results show that the design can effectively suppress the influence of unknown thermal noise and temperature rise delay on system measurement accuracy and stability, and achieve a good lock to the operating point, thus improving the system measurement accuracy and stability greatly. [ABSTRACT FROM AUTHOR]

An improvement of the Davydov’s model for energy transfer in α -helix protein is proposed. Using hyperbolic cosine potential type to model hydrogen bond potential, we have obtained from the adiabatic approximation, a discrete nonlinear Schrödinger equation with inverse hyperbolic sine nonlinearity. Using the two-dimensional discrete map approach, we have found a linearly stable intrinsic localized mode of the corresponding developed equation. Mobility of the intrinsic localized mode was achieved by moving the local impurity hypothesized as the anomalous band energy. The reactivity of the discrete breather under thermal noise was studied numerically with the Langevin’s approach. It was shown that the intrinsic localized mode in the developed model keep its shape longer under thermal bath. [ABSTRACT FROM AUTHOR]

It comes with your choice of lenses - a 1.55-mm f/2 fisheye lens with a 180-degree field of view that sees your entire sky all the way to the horizon, or a 2.55-mm f/1.2 lens with a 150-degree field of view. ALL-SKY MONITOR Starlight Xpress announces the Oculus PRO All-Sky Camera (£995). Starlight Xpress Unit 3, Brooklands Farm, Bottle Ln., Binfield, Berkshire, UK RG42 5QX +44 (0)1184026898; sxccd.com COMPACT MOUNT iOptron unveils its first mount to incorporate the latest drive technology: the HEM27 (starting at $1,888 for the head only). [Extracted from the article]

We analyze the role of the dynamical Casimir effect as a resource for quantum technologies, such as quantum cryptography and quantum metrology. In particular, we consider the generation of Einstein-Podolsky-Rosen steering and Gaussian interferometric power, two useful forms of asymmetric quantum correlations, in superconducting waveguides modulated by superconducting quantum interferometric devices. We show that while a certain value of squeezing is required to overcome thermal noise and give rise to steering, any nonzero squeezing produces interferometric power which in fact increases with thermal noise. [ABSTRACT FROM AUTHOR]

Thermal noise resulting from the mechanical loss of multilayer dielectric coatings is expected to impose a limit to the sensitivities of precision measurement systems used in fundamental and applied science. In the case of gravitational wave astronomy, future interferometric gravitational wave detectors are likely to operate at cryogenic temperatures to reduce such thermal noise and ameliorate thermal loading effects, with the desirable thermomechanical properties of silicon making it an attractive mirror substrate choice for this purpose. For use in such a precision instrument, appropriate coatings of low thermal noise are essential. Amorphous silicon (a-Si) deposited by e-beam and other techniques has been shown to have low mechanical loss. However, to date, the levels of mechanical and optical loss for a-Si when deposited by ionbeam sputtering (the technique required to produce amorphous mirrors of the specification for gravitational wave detector mirrors) are unknown. In this paper results from measurements of the mechanical loss of a series of IBS a-Si films are presented which show that reductions are possible in coating thermal noise of a factor of 1.5 at 120 K and 2.1 at 20 K over the current best IBS coatings (alternating stacks of silica and titania-doped tantala), with further reductions feasible under appropriate heat treatments. [ABSTRACT FROM AUTHOR]

This paper analyzes the thermal and reference noises of two types of successive-approximation-register (SAR) analog-to-digital converters (ADCs): the time-interleaving (TI) and the partial-interleaving (PI) Pipelined. The thermal noise is investigated with accurate estimation by deriving closed-form expressions according to the noise equivalent models on different phases. Additionally, the design trade-off between power and noise for two ADC architectures is discussed in detail. On the other hand, the reference noise due to the large switching transient, which significantly degrades the conversion accuracy, is analyzed and verified through behavioral and circuit level simulations of two ADC architectures operating at 500 MS/s for 10-bit resolution. The simulated results show the supremacy of the PI Pipelined-SAR (PS) architecture over the TI-SAR because it exhibits less reference noise sensitivity. [ABSTRACT FROM AUTHOR]

The generation of two-mode broadband squeezed light is investigated in cascading double-cavity optomechanical systems. The cavities are driven by amplitude-modulated lasers with two frequency tones, one of which is red detuning and other blue detuning from the cavity fields. It is shown that a two-mode squeezed field can be generated in a single double-cavity system via dissipation of the mechanical resonator. To generate broadband and strong squeezing of the cavity fields, many identical double-cavity optomechanical systems are connected together in a cascading way. The vacuum noise fed into the cavities and the thermal noise coupled to the mechanical resonator can be greatly depressed in the cascading system. As a result, the very strong and constant squeezing can be achieved in a large frequency range when the number of cascaded optomechanical systems becomes large. [ABSTRACT FROM AUTHOR]

On-chip True Random Number Generators (TRNG) are important cryptographic primitives in a variety of applications. In advanced CMOS process technologies, intra-die variations in transistor parameters bias the TRNG and degrade the statistics of the bit stream generated. In this work, we present a stochastic model for metastability based TRNG circuit incorporating both the impact of intra-die variations and thermal noise. The stochastic model is used to estimate the expected entropy out of a TRNG at a given process corner for variations in channel length and threshold voltage. We use the stochastic model to study the impact of variations on three lightweight post-processing techniques: von Neumann corrector, XOR function, and PRESENT cipher. The expected bit rate out of von Neumann corrector, number of XOR stages required for entropy extraction and the number of iterations for using PRESENT encryption are estimated for various process corners using the probabilistic entropy values. These analyses are further extended to different device sizing and operating voltage to explore the optimum trade-off between entropy extraction and energy overhead. A combination of HSPICE circuit simulation using 32 nm Predictive Technology models and stochastic modeling in MatLab show that XOR function and von Neumann corrector have an energy overhead ranging from 0.012pJ/bit to 0.15pJ/bit at the cost of decreased yield and bit-rate respectively. PRESENT cipher provides robust entropy extraction by increasing the number of encryption iterations from 1 for \mu/\sigma(Leff)<=6\% to 3 for \mu/\sigma(Leff)>8\%. With a maximum of 2.52pJ/bit PRESENT provides a more energy efficient solution compared to AES for entropy extraction in power constrained applications. [ABSTRACT FROM AUTHOR]

We present a multimode laser-linewidth theory for arbitrary cavity structures and geometries that contains nearly all previously known effects and also finds new nonlinear and multimode corrections, e.g., a correction to the a factor due to openness of the cavity and a multimode Schawlow-Townes relation (each linewidth is proportional to a sum of inverse powers of all lasing modes). Our theory produces a quantitatively accurate formula for the linewidth, with no free parameters, including the full spatial degrees of freedom of the system. Starting with the Maxwell-Bloch equations, we handle quantum and thermal noise by introducing random currents whose correlations are given by the fluctuation-dissipation theorem. We derive coupled-mode equations for the lasing-mode amplitudes and obtain a formula for the linewidths in terms of simple integrals over the steady-state lasing modes. [ABSTRACT FROM AUTHOR]

Optically levitated mechanical sensors promise isolation from thermal noise far beyond what is possible using flexible materials alone. One way to access this potential is to apply a strong optical trap to a minimally supported mechanical element, thereby increasing its quality factor Qm. Current schemes, however, require prohibitively high laser power (~10 W), and the Qm enhancement is ultimately limited to a factor of ~50 by hybridization between the trapped mode and the dissipative modes of the supporting structure. Here we propose a levitation scheme taking full advantage of an optical resonator to reduce the circulating power requirements by many orders of magnitude. Applying this scheme to the case of a dielectric disk in a Fabry-Perot cavity, we find a tilt-based tuning mechanism for optimizing both center-of-mass and torsional-mode traps. Notably, the two modes are trapped with comparable efficiency, and we estimate that a 10-µm-diameter, 100-nm-thick Si disk could be trapped to a frequency of ~10 MHz with only 30 mW circulating in a cavity of (modest) finesse 1500. Finally, we simulate the effect that such a strong trap would have on a realistic doubly tethered disc. Of central importance, we find torsional motion is comparatively immune to Qm-limiting hybridization, allowing a Qm-enhancement factor of ~1500. This opens the possibility of realizing a laser-tuned 10 MHz mechanical system with a quality factor on the order of 109. [ABSTRACT FROM AUTHOR]

Thermal electrical noise in living cells is considered to be the minimum threshold for several biological response mechanisms that pertain to electric fields. Existing models that purport to explain and interpret this phenomena yield perplexing results. The simplest model, in which the biomembrane is considered to be a linear dielectric, yields an equilibrium noise level that is several orders of magnitude larger than what is observed experimentally. An alternative approach of estimating the thermal noise as the Nyquist noise of a resistor within a finite frequency bandwidth, yields little physical insight. In this work, we argue that the nonlinear dielectric behavior must be accounted for. Using a statistical mechanics approach, we analyze the thermal fluctuations of a fully coupled electromechanical biomembrane. We develop a variational approximation to analytically obtain the benchmark results for model fluid membranes as well as physically reasonable estimates of the minimum electrical field threshold that can be detected by cells. Qualitatively, at least, our model is capable of predicting all known experimental results. The predictions of our model also suggest that further experimental work is warranted to clarify the inconsistencies in the literature. [ABSTRACT FROM AUTHOR]

In the coming years, the gravitational-wave community will be optimizing detector performance to target a variety of astrophysical sources which make competing demands on detector sensitivity in different frequency bands. In this paper we describe a number of technologies that are being developed as anticipated upgrades to the Advanced LIGO detectors and quantify the potential sensitivity improvement they offer. Specifically, we consider squeezed light injection for the reduction of quantum noise, detector design and materials changes which mitigate thermal noise and mirrors with significantly increased mass. We explore how each of these technologies impacts the detection of the most promising gravitational-wave sources and suggest an effective progression of upgrades which culminates in a twofold improvement in broadband sensitivity. [ABSTRACT FROM AUTHOR]

Future gravitational wave detectors (GWDs) such as Advanced LIGO upgrades and the Einstein Telescope are planned to operate at cryogenic temperatures using crystalline silicon (cSi) test-mass mirrors at an operation wavelength of 1550 nm. The reduction in temperature in principle provides a direct reduction in coating thermal noise, but the presently used coating stacks which are composed of silica (SiO2) and tantala (Ta2O5) show cryogenic loss peaks which results in less thermal noise improvement than might be expected. Due to low mechanical loss at low temperature amorphous silicon (aSi) is a very promising candidate material for dielectric mirror coatings and could replace Ta2O5. Unfortunately, such an aSi/SiO2 coating is not suitable for use in GWDs due to high optical absorption in aSi coatings. We explore the use of a three material based coating stack. In this multimaterial design the low absorbing Ta2O5 in the outermost coating layers significantly reduces the incident light power, while aSi is used only in the lower bilayers to maintain low optical absorption. Such a coating design would enable a reduction of Brownian thermal noise by 25%. We show experimentally that an optical absorption of only (5.3 ± 0.4) ppm at 1550 nm should be achievable. [ABSTRACT FROM AUTHOR]

The most sensitive measurements of time and space are made with resonant optical cavities, and these measurements are limited by coating thermal noise. The mechanical and optical performance requirements placed on coating materials, especially for interferometric gravitational wave detectors, have proven extremely difficult to meet despite a lengthy search. In this paper we propose a new approach to high performance coatings, the use of multiple materials at different depths in the coating. To support this we generalize previous work on thermal noise in two-material coatings to an arbitrary multimaterial stack, and develop a means of estimating absorption in these multimaterial coatings. This new approach will allow for a broadening of the search for high performance coating materials. [ABSTRACT FROM AUTHOR]

We estimate the loss angles of the materials currently used in the highly reflective test-mass coatings of interferometric detectors of gravitational waves, namely Silica, Tantala, and Ti-doped Tantala, from direct measurement of coating thermal noise in an optical interferometer testbench, the Caltech TNI. We also present a simple predictive theory for the material properties of amorphous glassy oxide mixtures, which gives results in good agreement with our measurements on Ti-doped Tantala. Alternative measurement methods and results are reviewed, and some critical issues are discussed. [ABSTRACT FROM AUTHOR]

We consider a system subject to a quantum optical master equation at finite temperature and study a class of conditional dynamics obtained by monitoring its totally or partially purified environment. More specifically, drawing from the notion that the thermal state of the environment may be regarded as the local state of a lossy and noisy two-mode squeezed state, we consider conditional dynamics ("unravellings") resulting from the homodyne detection of the two modes of such a state. Thus, we identify a class of unravellings parametrized by the loss rate suffered by the environmental two-mode state, which interpolate between direct detection of the environmental mode alone (occurring for total loss, whereby no correlation between the two environmental modes is left) and full access to the purification of the bath (occurring when no loss is acting and the two-mode state of the environment is pure). We hence show that, while direct detection of the bath is not able to reach the maximal steady-state squeezing allowed by general-dyne unravellings, such optimal values can be obtained when a fully purified bath is accessible. More generally we show that, within our framework, any degree of access to the bath purification improves the performance of filtering protocols in terms of achievable squeezing and entanglement. [ABSTRACT FROM AUTHOR]