Crosstalk Problem Research Articles

Enhancing Learning to Solve Multicomponent Fractional Viscoelastic Equations with U-net Fourier Neural Operators

Abstract The research of viscoelastic media is currently a hot topic in the interpretation and processing of seismic data. To accurately simulate the propagation of seismic waves in viscoelastic media, the fractional viscoelastic equation has emerged as an indispensable method. However, solving this equation numerically has proven to be challenging due to the complexity introduced by its fractional Laplacian operators. Recently, deep learning, especially Fourier neural operators (FNO), has shown excellent performance in learning to fast solve partial differential equations. Traditional FNO methods may face crosstalk problem and make it difficult to achieve satisfactory accuracy, when solving the multi-component fractional order viscoelastic equation. To solve this problem, we introduce a novel approach based on U-net Fourier neural operator (U-FNO). As an enhanced learning method to the traditional FNO-based method, the U-FNO-based method integrates a U-Fourier layer following the standard Fourier layer as a form of regularization, thereby achieving superior prediction accuracy for multi-component equations. Specifically, both the Fourier layers and U-Fourier layers in U-FNO are trained with the solutions of the equation from previous time steps as inputs. This training process enables the U-FNO to efficiently produce more accurate solutions for subsequent wavefield. Numerical simulations reveal that the U-FNO-based method efficiently learns to solve the fractional viscoelastic wave equation independent of fractional Laplacian operators. Additionally, U-FNO-based method offers superior prediction accuracy in comparison with the traditional FNO-based method.

Improved Design of a SiC MOSFET Gate Drive with Crosstalk Suppression Capability

For high-frequency switching applications, silicon carbide (SiC) devices are more suitable than silicon-based devices, which is conducive to improving the efficiency and power density of power electronic equipment. However, as the switching frequency increases, the influence of parasitic parameters on the switching characteristics of devices becomes increasingly apparent. When SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) are applied in bridge circuits, the crosstalk problem easily occurs with the complementary conduction of upper and lower transistors, which seriously limits the promotion of SiC MOSFETs. However, the existing crosstalk suppression drive circuit tends to increase the switching loss, switching delay, and control complexity; therefore, a gate drive with crosstalk suppression capability is proposed. In this paper, the gate drive has two features: a negative voltage to shut down the SiC MOSFET; and an adjustment of the gate-source equivalent impedance. To accomplish this goal, the mechanism of crosstalk voltage generation is analyzed. Furthermore, the operation principle of the gate drive is analyzed, and the parameters of the gate drive are designed. Eventually, the proposed gate drive is verified by an LTspice simulation and experimental platform. The results prove that the gate drive can suppress the crosstalk voltage without affecting the switching speed.

A high-sensitivity balloon-type optical fiber sensor enables wide-range strain sensing with the assistance of CNN

A balloon-type optical fiber sensor (OFS) for strain measurement was proposed, and the measurement range was significantly increased with the assistance of convolutional neural networks (CNN). The presented OFS was prepared by bending a Mach-Zehnder structure based on polarization-maintaining fibers into a balloon-type, which exhibits a sensitivity of 26.3 pm/με under the strain range from 0 to 300 με. The CNN-based signal analysis method can effectively extract the data information in the spectral, and the strain range that can be measured is greatly enlarged to 0–2000 με, while the accuracy of the measurement can be guaranteed. Further, the temperature sensitivity of the OFS is −0.0252 nm/°C; the lower temperature sensitivity can effectively suppress the crosstalk problem caused by temperature changes during strain measurement. The proposed method remarkably increases the strain measurement range of OFS, which is conducive to the application and development of OFSs.

P‐40: Improvement Plan for High Brightness MiniLED BLU VR Crosstalk

With the rise of the concept of "meta‐universe", VR/AR products have received more and more attention. This paper introduces the crosstalk problem of ultra‐high resolution VR products. The mechanism of the ultra‐high resolution VR crosstalk problem is discussed. Crosstalk problems, such as the reduction of high‐light backlight by membrane optimization, are studied in depth. Finally, it briefly introduces the technical challenges facing the resolution improvement of ultra‐high resolution VR.

Temperature-insensitive vector curvature sensor based on four-core fiber offset structure

Vector curvature measurement is very important in industrial fields with the unavoidable problem of temperature crosstalk. To improve the detection performance, a novel temperature-insensitive vector bending sensor have been proposed in the paper. The sensor is fabricated by core-offset splicing a segment of four-core fiber (FCF) between two single-mode fibers (SMFs). The Mach-Zehnder interference and the recognition ability of bending directions are enhanced by the core-offset structure. The experimental results demonstrate the curvature sensitivities of our sensor reach 38.16 nm/m−1, 37.46 nm/m−1, 4.99 nm/m−1 and −7.12 nm/m−1 in different bending directions within the range of 0.346–0.49 m−1. The average temperature sensitivity is only −6.67 pm/℃ in the range of 30–90 °C. The all-fiber, low cost, high sensitivity, and excellent vectoriality make our sensor more potential in harsh, complex industrial environment.

Adaptive structure-based full-waveform inversion

In simultaneous-shot full-waveform inversion (FWI), the re-started limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm can be used to suppress crosstalk, but crosstalk cannot be completely eliminated from the inversion results. To further solve the crosstalk problem caused by the interference among individual shots in simultaneous-shot FWI, adaptive structure-based smoothing is applied to the FWI with the restarted L-BFGS algorithm. Structure-based smoothing can mitigate the crosstalk by highlighting structure boundaries. To perform structure-based smoothing, an implicit anisotropic diffusion equation is solved. We carry out a multiscale inversion strategy. Because the FWI results in the low-frequency band contain less structural information and more crosstalk, structure-based smoothing is applied to the frequency band at frequencies higher than the peak frequency to prevent negative effects from the model structure in the low-frequency band. The estimated structural information is iteratively updated during the inversion process. Furthermore, structure-based smoothing is only added to the iterations with invariant encoding to reduce oversmoothing. The invariant encoding means that the shot encoding remains unchanged between iterations. Numerical experiments with an overthrust model indicate that the proposed adaptive structure-based FWI method can effectively suppress artifacts and provide a high-resolution inversion result, even when the encoded data are contaminated with strong noise. Another advantage of the adaptive structure-based FWI method is that no seismic migration needs to be performed, which makes it more efficient for real data.

Research on decoupled transfer path analysis method and its application in hybrid mechanical systems

As a key technique of vibration control, transfer path analysis (TPA) provides theoretical support for diagnosis, analysis, evaluation, and optimization of vibration in mechanical systems. The coupling phenomena often exists in the vibration transfer paths of complex mechanical systems, which makes most of the existing TPA methods unable to accurately analyze the transfer function of the coupled paths. The classical transfer path analysis (CTPA) is an effective method to solve the problem of path coupling, but it changes the inherent characteristics of the system, the results can not accurately reflect the vibration transfer characteristics of the system. In order to overcome the disadvantages of CTPA method, a decoupled transfer path analysis (DTPA) method is proposed in this paper, and the implementation process of this method is introduced by taking a hybrid mechanical system as an example. The results show that DTPA method can solve the path crosstalk problem and accurately calculate the transfer function of each path.

Research on interference compensation methods for color image sensors based on iterative learning

PurposeFixed mode noise and random mode noise always exist in the image sensor, which affects the imaging quality of the image sensor. The charge diffusion and color mixing between pixels in the photoelectric conversion process belong to fixed mode noise. This study aims to improve the image sensor imaging quality by processing the fixed mode noise.Design/methodology/approachThrough an iterative training of an ergoable long- and short-term memory recurrent neural network model, the authors obtain a neural network model able to compensate for image noise crosstalk. To overcome the lack of differences in the same color pixels on each template of the image sensor under flat-field light, the data before and after compensation were used as a new data set to further train the neural network iteratively.FindingsThe comparison of the images compensated by the two sets of neural network models shows that the gray value distribution is more concentrated and uniform. The middle and high frequency components in the spatial spectrum are all increased, indicating that the compensated image edges change faster and are more detailed (Hinton and Salakhutdinov, 2006; LeCun et al., 1998; Mohanty et al., 2016; Zang et al., 2023).Originality/valueIn this paper, the authors use the iterative learning color image pixel crosstalk compensation method to effectively alleviate the incomplete color mixing problem caused by the insufficient filter rate and the electric crosstalk problem caused by the lateral diffusion of the optical charge caused by the adjacent pixel potential trap.

Optimizing for periodicity: a model-independent approach to flux crosstalk calibration for superconducting circuits

Flux tunability is an important engineering resource for superconducting circuits. Large-scale quantum computers based on flux-tunable superconducting circuits face the problem of flux crosstalk, which needs to be accurately calibrated to realize high-fidelity quantum operations. Typical calibration methods either assume that circuit elements can be effectively decoupled and simple models can be applied, or require a large amount of data. Such methods become ineffective as the system size increases and circuit interactions become stronger. Here we propose a new method for calibrating flux crosstalk, which is independent of the underlying circuit model. Using the fundamental property that superconducting circuits respond periodically to external fluxes, crosstalk calibration of N flux channels can be treated as N independent optimization problems, with the objective functions being the periodicity of a measured signal depending on the compensation parameters. We demonstrate this method on a small-scale quantum annealing circuit based on superconducting flux qubits, achieving comparable accuracy with previous methods. We also show that the objective function usually has a nearly convex landscape, allowing efficient optimization.

Research on multi-image encryption method based on image scaling and ghost imaging

Optical information processing technology itself is characterized by high speed and parallelism, while the wavelength of light is short and the loading information capacity is large. Therefore, optical encryption is of great significance in the field of image encryption. For multi-image encryption, a multi-image encryption system (ISK-MGI) based on image scaling and ghost imaging is proposed in this paper. In the encryption process, image scaling is used to embed the image information to be encrypted into the artifact image to achieve the first step of artifact encryption; then the ghost imaging encryption is used to encrypt any of the artifact images and the intensity sequence obtained from the barrel detector is used as the cipher text; the integration property of Fourier transform is used to obtain the modulation patterns of other artifact images as the key. The feasibility, security and robustness of the scheme are verified by experiments and simulations. The scheme not only solves the image information crosstalk problem of multi-image encryption, but also has high security. Each image in this method has a primary public key and a secondary private key, which solves the potential risk of sharing public keys and provides a new idea for optical information encryption.

Linearized waveform inversion for vertical transversely isotropic elastic media: Methodology and multi-parameter crosstalk analysis

Seismic migration and inversion are closely related techniques to portray subsurface images and identify hydrocarbon reservoirs. Seismic migration aims at obtaining structural images of subsurface geologic discontinuities. More specifically, seismic migration estimates the reflectivity function (stacked average reflectivity or pre-stack angle-dependent reflectivity) from seismic reflection data. On the other hand, seismic inversion quantitatively estimates the intrinsic rock properties of subsurface formulations. Such seismic inversion methods are applicable to detect hydrocarbon reservoirs that may exhibit lateral variations in the inverted parameters. Although there exist many differences, pre-stack seismic migration is similar with the first iteration of the general linearized seismic inversion.Usually, seismic migration and inversion techniques assume an acoustic or isotropic elastic medium. Unconventional reservoirs such as shale and tight sand formation have notable anisotropic property. We present a linearized waveform inversion (LWI) scheme for weakly anisotropic elastic media with vertical transversely isotropic (VTI) symmetry. It is based on two-way anisotropic elastic wave equation and simultaneously inverts for the localized perturbations (ΔVp0/Vp0,ΔVs0/Vs0,Δϵ,Δδ) from the long-wavelength reference model. Our proposed VTI-elastic LWI is an iterative method that requires a forward and an adjoint operator acting on vectors in each iteration. We derive the forward Born approximation operator by perturbation theory and adjoint operator via adjoint-state method. The inversion has improved the quality of the images and reduces the multi-parameter crosstalk comparing with the adjoint-based images. We have observed that the multi-parameter crosstalk problem is more prominent in the inversion images for Thomsen anisotropy parameters. Especially, the Thomsen parameter δ is the most difficult to resolve. We also analyze the multi-parameter crosstalk using scattering radiation patterns.The linearized waveform inversion for VTI-elastic media presented in this article provides quantitative information of the rock properties that has the potential to help identify hydrocarbon reservoirs.

Thermal characteristics of high-power vertical cavity surface emitting laser array

Due to the excellent characteristics such as good beam quality, dynamic single-longitudinal mode, low power consumption, and good wavelength stability, especially easy-to-integrate high-density 2D area arrays, vertical-cavity surface-emitting laser (VCSEL) is widely used in optical identification, optical interconnection systems, optical data storage and other fields. In recent years, with the improvement of materials and process technology, VCSEL has played an increasingly important role in the fields of smartphone face recognition, drone obstacle avoidance, virtual reality/augmented reality (VR/AR), sweeping robots, home cameras, etc., and with the rapid development and application of 5G communication, VCSEL will become an indispensable main component. However, due to the introduction of distributed Bragg mirrors, the thermal effect of VCSEL is very serious, especially when VCSEL is integrated into an array device, current-induced self-heating of each individual array cell and the thermal coupling among array cells have become the major factors contributing to thermal rollover and hence restraining the optical output performance of the VCSEL arrays. Therefor it is of great significance to study the thermal characteristics of VCSELs, in order to solve the problem of thermal crosstalk between single-tube devices, and increase the life of the device. This paper analyzes the influence of cell spacing and arrangement on the thermal crosstalk phenomenon and thermal diffusion performance of VCSEL array device based on the finite element model. The simulation results show that the maximum temperature of the device decays exponentially with the increase of cell spacing, the thermal crosstalk phenomenon and thermal diffusion performance of VCSEL array devices are significantly improved. When the cell spacing is 120 μm, the influence between the cells is small, the thermal crosstalk phenomenon is significantly improved, and the heat dissipation effect is better. On this basis, four non-square VCSEL arrays with 16 cells are designed, and it can be seen that compared with the square arrangement, the isosceles triangle, pentagonal and hexagonal configurations have improved the thermal crosstalk phenomenon and thermal diffusion performance, and the overall temperature rise of the VCSEL array is significantly reduced. The thermal crosstalk phenomenon of the pentagonal arrangement is significantly improved, and the device temperature is 37.32 ℃, which is the best effect among several arrangement methods. According to the results of theoretical simulation, the VCSEL array devices with different arrangements are prepared and characterized on the same epitaxial wafer by the same process. From the <i>P</i>-<i>I</i>-<i>V</i> characteristic curves, it can be seen that the threshold currents of isosceles triangles, pentagons and hexagons are lower than those of the square arrangement, and the maximum output power is higher than that of the square arrangement, especially the maximum output power value of the pentagonal is 150 mW. The results show that the new arrangement can effectively improve the thermal crosstalk phenomenon between the cells, increase the output power of the device, and make the VCSEL array device have good optoelectronic and thermal characteristics.

Rational design of pH probes with large Stokes shift for tracking lysosome-mitochondria interactions

Tracking the interactions of lysosomes with other organelles by fluorescence imaging is the key to understanding cellular homeostasis. Herein, we focus on the problem of fluorescence crosstalk caused by the small Stokes shift in lysosomes targeted pH probes and introduce rhodamine dyes with large Stokes shift to construct pH probes. In order to accurately construct a probe suitable for lysosomal pH, we established the relationship between the atomic dipole moment-corrected Hirshfeld population (ADCH) charge of rhodamines and pKa values of the corresponding pH probes. The large Stokes shift rhodamine DQF-584 was predicted and verified as the suitable dye to construct lysosomal pH probe. The photostable probe DQF-pH with large Stokes shift of 91 nm could effectively localize in lysosomes and applied in tracking the dynamics of lysosome-mitochondrial interactions.

Ln-HOF Nanofiber Organogels with Time-Resolved Luminescence for Programmable and Reliable Encryption.

Developing tunable luminescent materials for high throughput information storage is highly desired following the explosive growth of global data. Although considerable success has been achieved, achieving programmable information encryption remains challenging due to current signal crosstalk problems. Here, we developed long-lived room-temperature phosphorescent organogels enabled by lanthanum-coordinated hydrogen-bonded organic framework nanofibers for time-resolved information programming. Via modulating coassembled lanthanum concentration and Förster resonance energy transfer efficiency, the lifetimes are prolonged and facilely manipulated (20-644 ms), realizing encoding space enlargement and multichannel data outputs. The aggregated strong interfacial supramolecular bonding endows organogels with excellent mechanical toughness (36.16 MJ m-2) and self-healing properties (95.7%), synergistically achieving photostability (97.6% lifetime retention in 10000 fatigue cycles) via suppressing nonradiative decays. This work presents a lifetime-gated information programmable strategy via lanthanum-coordination regulation that promisingly breaks through limitations of current responsive luminescent materials, opening unprecedented avenues for high-level information encryption and protection.

Development and optimization of a frequency mixing sensor for adjacent samples quantitative detection on a lateral flow assay.

Frequency-mixing technology has been widely used to precisely identify magnetic nanoparticles in applications of quantitative biomedical detection in recent years. Examples include immune adsorption, lateral flow assays (LFAs), and biomagnetic imaging. However, the signals of magnetic response generated by adjacent magnetic samples interfere with each other owing to the small spacing between them in applications involving multi-sample detection (such as the LFA and multiplexing detection). Such signal interference prevents the biosensor from obtaining characteristic peaks related to the concentration of adjacent biomarkers from the magnetic response signals. Mathematical and physical models of the structure of sensors based on frequency-mixing techniques were developed. The theoretical model was verified and its key parameters were optimized by using simulations. A new frequency-mixing magnetic sensor structure was then designed and developed based on the model, and the key technical problem of signal crosstalk between adjacent samples was structurally solved. Finally, standard cards with stable magnetic properties were used to evaluate the performance of the sensor, and strips of the gastrin-17 (G-17) LFA were used to evaluate its potential for use in clinical applications. The results show that the minimum spacing between samples required by the optimized sensor to accurately identify them was only about 4-5mm, and the minimum detectable concentration of G-17 was 11 pgmL-1 . This is a significant reduction in the required spacing between samples for multiplexing detection. The optimized sensor also has the potential for use in multi-channel synchronous signal acquisition, and can be used to detect synchronous magnetic signals in vivo.

Optical link encoding based simultaneous correction for crosstalk and nonlinearity in multi-site optical converged networks.

This paper reports a correction scheme to address the problem of modulation nonlinearity and optical switch crosstalk simultaneously for the multi-site optical converged network. Based on the optical link encoding and exclusive-or operation for the received signal, the present spectrum usage can be obtained among the confusion with interferences containing the modulated harmonic distortion and the crosstalk leakage from other sites. The proof-of-concept experiment is performed on various interferences involving the linear frequency modulated (LFM) waveform and the quadrature amplitude modulation (QAM) signal. The corrected spectrum has realized an improved signal-to-noise ratio (SNR) of over 22 dB compared to the uncorrected counterpart. Furthermore, it consistently maintains a superior SNR, surpassing the single impairment-corrected scenario by an impressive margin of at least 15.9 dB. Besides, the implementation would not introduce additional noise, making the corrected result agree well with the ideal case. Without any increase in hardware complexity, the presented scheme provides an effective technique to meet the correction challenge of large-scale and complicated optical networks with multiple optoelectronic devices.

Rapid Analysis of Bent Cable Crosstalk Based on Numerical Calculation

In this paper, a fast prediction method of cable crosstalk is introduced, which can simulate the crosstalk problem more accurately in the actual cable situation. The traditional flexible cable model considers few factors to truly reflect the spatial pose of the cable. In this paper, constraints of the assembly space are considered to truly reflect the structural characteristics of the cable, providing a theoretical basis for cable bundle layout in the virtual environment. Based on the element method and the theory of multi-conductor transmission lines, the crosstalk coupling model of curved cable is established. In this model, the traditional multi-conductor transmission line theory is improved, and the bending cable bundle model is divided into several equivalent subsegments by using the element method. In the subsegment, the multi-conductor transmission line theory is used for modeling, and the chain parameter method is used for crosstalk coupling analysis. The accuracy of the model introduced in this paper is verified by MATLAB and CST Studio simulation.

Crosstalk-free for multi-plane holographic display using double-constraint stochastic gradient descent.

Multi-plane crosstalk is a key issue affecting the quality of holographic three-dimensional (3D) displays. The time-multiplexing stochastic gradient descent (TM-SGD) method has been applied to solve the inter-plane crosstalk problem in multi-plane reconstruction. However, the inter-plane crosstalk increases greatly as the inter-plane interval decreases, and the optimization time increases greatly as the number of planes increases. In this paper, we propose a double-constraint stochastic gradient descent method to suppress inter-plane crosstalk in multi-plane reconstruction. In the proposed method, we use the mask to make the optimization process focus more on the signal region and improve the reconstruction quality. Meanwhile, we adopt a constraint strategy of phase regularization to reduce the phase randomness of the signal region and suppress inter-plane crosstalk. Numerical simulation and optical experiment results confirm that our method can effectively suppress the inter-plane crosstalk and improve the quality of the reconstructed planes at a lower inter-plane interval. Moreover, the optimization time of our method is almost 4 times faster than that of TM-SGD. The proposed method can contribute to the realization of tomographic 3D visualization in the biomedical field, which requires the reconstruction of multiple tomographic images without inter-plane crosstalk.

Design and simulation of a flexible piezoelectric sensing array with stable sensitivity and high duty cycle

Flexible piezoelectric sensing arrays (FPSA) have an irreplaceable role in the fields of stress detection and self-energy supply and are part of the current hotspots of research in flexible electronics. In this paper, a FPSA with stable sensitivity and high duty cycle is designed to achieve high sensitivity over a wide range and a high duty cycle of 84.17%. The sensing unit uses two inverted trapezoidal prismatic structures (ITPS) with piezoelectric layers with stable sensitivity to pressure. For practical fabrication, a single-electrode array and cut package are proposed to solve the crosstalk problem between the highly duty cycle array units. The single-electrode array reduces the array structure’s complexity and the process’s difficulty. The cut package reduces crosstalk between units and improves the stress sensitivity of the array. Comsol Multiphysics and Abaqus provide strong validation and analysis of this design. The designed FPSA, which has demonstrated excellent performance in simulation analysis, significantly decreases the time and economic cost of device preparation. Given the compelling features, this study offers an effective solution for mitigating unit crosstalk in flexible sensing arrays, which hold significant academic research promise and application value.

A High Crosstalk Suppression SiC MOSFET Gate Driver

Fast switching speeds and high switching frequencies bring serious crosstalk problems in SiC MOSFET applications. In this paper, we design a SiC MOSFET gate driver with high crosstalk suppression capability by using a multi-level drive and active Miller clamp technology. In the design, an auxiliary branch is introduced to control the source potential of the SiC MOSFET to achieve multilevel driving. The branch has a simple structure, simple control logic, no external negative voltage supply, and adjustable negative output voltage. The proposed SiC MOSFET gate driver was designed using the Central Semiconductor Manufacturing Corporation (CSMC) 0.8 μm BCD high voltage process. The designed SiC MOSFET gate driver has an area of 2967 μm × 3180 μm. The simulation verification model is based on Wolfspeed’s SiC MOSFET product C3M0075120D. Post-layout simulation results show that a SiC MOSFET gate driver with a crosstalk suppression capability of over 150 V/ns is obtained, which can reliably drive SiC MOSFET power devices.