arXiv subjects

Binbin Tang

Publications and source records attributed to Binbin Tang.

5 recordsLinked to original sources

arXiv2024

Analysis of the background signal in Tianwen-1 MINPA

Since November 2021, Tianwen-1 started its scientific instrument Mars Ion and Neutral Particle Analyzer (MINPA) to detect the particles in the Martian space. To evaluate the reliability of the plasma parameters from the MINPA measurements, in this study, we analyze and reduce the background signal (or noise) appearing in the MINPA data, and then calculate the plasma moments based on the noise-reduced data. It is found that the velocity from MINPA is highly correlated with that from the Solar Wind Ion Analyzer (SWIA) onboard the MAVEN spacecraft, indicating good reliability, and the temperature is also correlated with the SWIA data, although it is underestimated and has more scatter. However, due to the limited $2\pi$ field of view (FOV), it's impossible for MINPA to observe the ions in all directions, which makes the number density and the thermal pressure highly underestimated compared to the SWIA data. For these moments, a more complicated procedure that fully takes into account the limited FOV is required to obtain their reliable values. In addition, we perform a detailed analysis of the noise source and find that the noise comes from the electronic noise in the circuits of MINPA. Based on this study, we may conclude that MINPA is in normal operating condition and could provide reliable plasma parameters by taking some further procedures. The analysis of the noise source can also provide a reference for future instrument design.

physics.space-ph↗

arXiv2024

A Review of Carsickness Mitigation: Navigating Challenges and Exploiting Opportunities in the Era of Intelligent Vehicles

Motion sickness (MS) has long been a common complaint in road transportation. However, in the era of driving automation, MS has become an increasingly significant issue. The future intelligent vehicle is envisioned as a mobile space for work or entertainment, but unfortunately passengers' engagement in non-driving tasks may exacerbate MS. Finding effective MS countermeasures is crucial to ensure a pleasant passenger experience. Nevertheless, due to the complex mechanism of MS, there are numerous challenges in mitigating it, hindering the development of practical countermeasures. To address this, we first review two prevalent theories explaining the mechanism of MS. Subsequently, this paper provides a summary of current subjective and objective approaches for quantifying motion sickness levels. Then, it surveys existing methods for alleviating MS, including passenger adjustment, intelligent vehicle solutions, and motion cues of various modalities. Furthermore, we outline the limitations and remaining challenges of current research and highlight novel opportunities in the context of intelligent vehicles. Finally, we propose an integrated framework for alleviating MS. The findings of this review will enhance our understanding of carsickness and offer valuable insights for future research and practice in MS mitigation within modern vehicles.

eess.SY↗

arXiv2023

Unveiling the Mixing and Transport Processes of Solar Wind and Planetary Ions in the Magnetopause Boundary Layer

Kelvin-Helmholtz (KH) vortices are widely observed in astrophysics and heliophysics, including at Jovian and terrestrial magnetopauses, the Martian sheath-ionosphere boundary, the heliopause, and within stellar accretion disks. These vortices play a critical role in transporting mass, momentum, and energy across boundary layers. Magnetized planets such as Earth exhibit a higher incidence of fully rolled-up, nonlinear KH vortices compared to non-magnetized planets like Mars. In contrast to previous magnetohydrodynamic (MHD) studies, this work adopts a kinetic point of view to quantify ion mixing rates using three-dimensional global hybrid simulations, with Earth as a representative case. This approach enables automated identification of the KH-modulated, corrugated magnetopause. For the first time, we provide a quantitative assessment of how solar wind conditions control solar wind entry and subsequent mixing with magnetospheric ions via KH waves. We find that under northward interplanetary magnetic field (IMF) conditions, the flux of particles crossing the dayside magnetopause increases with solar wind dynamic pressure and peaks in the KH region. Notably, the KH-modulated low-latitude boundary layer thins as the dynamic pressure increases. Under southward IMF conditions, coupled reconnection and KH structures further enhance solar wind injection and boost magnetospheric ion escape in the dayside, especially near the subsolar point where reconnection intensifies this exchange. These results also shed light on the evolution of space environments and mass transport at magnetized planets in the heliosphere and beyond.

physics.space-ph↗

arXiv2022

Plasma noise in TianQin time delay interferometry

TianQin is a proposed geocentric space-based gravitational wave observatory mission, which requires time-delay interferometry (TDI) to cancel laser frequency noise. With high demands for precision, solar-wind plasma environment at $\sim 10^5$ km above the Earth may constitute a non-negligible noise source to laser interferometric measurements between satellites, as charged particles perturb the refractivity along light paths. In this paper, we first assess the plasma noises along single links from space-weather models and numerical orbits, and analyze the time and frequency domain characteristics. Particularly, to capture the plasma noise in the entire measurement band of $10^{-4} - 1$ Hz, we have performed additional space-weather magnetohydrodynamic simulations in finer spatial and temporal resolutions and utilized Kolmogorov spectra in high-frequency data generation. Then we evaluate the residual plasma noises of the first- and second-generation TDI combinations. Both analytical and numerical estimations have shown that under normal solar conditions the plasma noise after TDI is less than the secondary noise requirement. Moreover, TDI is shown to exhibit moderate suppression on the plasma noise below $\sim 10^{-2}$ Hz due to noise correlation between different arms, when compared with the secondary noise before and after TDI.

gr-qc↗

arXiv2016

Large Scale GPU Accelerated PPMLR-MHD Simulations for Space Weather Forecast

PPMLR-MHD is a new magnetohydrodynamics (MHD) model used to simulate the interactions of the solar wind with the magnetosphere, which has been proved to be the key element of the space weather cause-and-effect chain process from the Sun to Earth. Compared to existing MHD methods, PPMLR-MHD achieves the advantage of high order spatial accuracy and low numerical dissipation. However, the accuracy comes at a cost. On one hand, this method requires more intensive computation. On the other hand, more boundary data is subject to be transferred during the process of simulation.s In this work, we present a parallel hybrid solution of the PPMLR-MHD model implemented using the computing capabilities of both CPUs and GPUs. We demonstrate that our optimized implementation alleviates the data transfer overhead by using GPU Direct technology and can scale up to 151 processes and achieve significant performance gains by distributing the workload among the CPUs and GPUs on Titan at Oak Ridge National Laboratory. The performance results show that our implementation is fast enough to carry out highly accurate MHD simulations in real time.

cs.DC↗