arXiv subjects

Liping Meng

Publications and source records attributed to Liping Meng.

5 recordsLinked to original sources

arXiv2026

Optimizing Neural Network Architecture for Medical Image Segmentation Using Monte Carlo Tree Search

This paper proposes a novel medical image segmentation framework, MNAS-Unet, which combines Monte Carlo Tree Search (MCTS) and Neural Architecture Search (NAS). MNAS-Unet dynamically explores promising network architectures through MCTS, significantly enhancing the efficiency and accuracy of architecture search. It also optimizes the DownSC and UpSC unit structures, enabling fast and precise model adjustments. Experimental results demonstrate that MNAS-Unet outperforms NAS-Unet and other state-of-the-art models in segmentation accuracy on several medical image datasets, including PROMISE12, Ultrasound Nerve, and CHAOS. Furthermore, compared with NAS-Unet, MNAS-Unet reduces the architecture search budget by 54% (early stopping at 139 epochs versus 300 epochs under the same search setting), while achieving a lightweight model with only 0.6M parameters and lower GPU memory consumption, which further improves its practical applicability. These results suggest that MNAS-Unet can improve search efficiency while maintaining competitive segmentation accuracy under practical resource constraints.

cs.CV↗

arXiv2025

Periodic Orbits and Gravitational Wave Radiation of Black Hole in EGB gravity

This paper investigates the orbital dynamics and gravitational wave radiation characteristics of neutral test particles around a static spherically symmetric charged black hole (BH) in 4D Einstein-Gauss-Bonnet (4D-EGB) gravity theory. We analyze the dependence of the marginally bound orbit (MBO) and the innermost stable circular orbit (ISCO) on the Gauss-Bonnet coupling parameter $\alpha$ and charge $Q$. The results indicate that the orbital radius, angular momentum, and energy all decrease with increasing $\alpha$ or $Q$, with the corresponding bound orbit region shifting leftward in the $(E, L)$ parameter space. By combining observational data from the BH shadows of M87* and Sgr A* as well as the orbital precession of the S2 star, we constrain the model parameters and find that existing observations can limit the ranges of $\alpha$ and $Q$ to a certain extent. Furthermore, we investigate the characteristics of periodic orbits corresponding to different rational numbers $q$ and the gravitational waveforms they excite, finding that variations in $\alpha$ and $Q$ can lead to distinguishable differences in periodic orbit structures and gravitational wave phases. This study contributes to understanding the effects of Gauss-Bonnet corrections on BH spacetimes, and the results may provide theoretical references for future gravitational wave observations of extreme mass ratio inspirals (EMRIs).

gr-qc↗

arXiv2024

Bound Orbits and Gravitational Wave Radiation Around the Hairy Black Hole

The hairy black hole model provides a new theoretical framework for exploring phenomena in strong gravitational fields. This paper systematically investigates the influence of the hair parameter $\beta$ on the timelike geodesics of the regular hairy black hole, including the radius of the event horizon, the properties of bound orbits, and the characteristics of gravitational wave radiation over a single period. The study reveals that $\beta$ has a significant impact on the event horizon but only a minor effect on the innermost stable circular orbit(ISCO), the marginally bound orbit(MBO), and periodic orbits. Moreover, the trajectories of the periodic orbits are nearly identical to those of the Schwarzschild black hole. In addition, the parameter $\beta$ was constrained by simulating the precession observational data of the S2 star orbiting the supermassive black hole Sgr A*. The results indicate that the correction effects of $\beta$ comply with existing observational constraints, without providing stricter limitations. Furthermore, by considering periodic orbits as transitional orbits in the extreme-mass-ratio inspiral (EMRI) system, it is found that the presence of $\beta$ introduces subtle effects on the amplitude, phase, and period of the gravitational wave signal for a single orbit. Although these effects appear minor within a single cycle, they may accumulate into significant effects over long-term evolution. In the future, space-based gravitational wave detectors are expected to further investigate the properties of the hair parameter, enhancing our understanding of the spacetime structure and dynamical behavior of black holes.

gr-qc↗

arXiv2024

Destroying the Event Horizon of Cold Dark Matter-Black Hole System

Since the Weak Cosmic Censorship Conjecture was proposed, research on this conjecture has been ongoing. This paper explores the conjecture in black holes that are closer to those existing in the real universe (i.e., rotating black holes enveloped by dark matter). In this paper, we obtained a first-order corrected analytical solution for the black hole event horizon through an approximate solution. The validity of the first-order corrected analytical solution will be provided in the appendix. We conduct our study by introducing a test particle and a scalar field into the black hole. Our conclusions show that, in extremal case, both a test particle and a scalar field can disrupt the event horizon of the Kerr-like black hole; in near-extremal case, both a test particle and a scalar field can disrupt the event horizon of the Kerr-like black hole. When cold dark matter is not considered, the conclusion is consistent with previous research.

gr-qc↗

arXiv2023

Test the Weak Cosmic Supervision Conjecture in Dark Matter-Black Hole System

There is a possibility that the event horizon of a Kerr-like black hole with perfect fluid dark matter (DM) can be destroyed, providing a potential opportunity for understanding the weak cosmic censorship conjecture of black holes. In this study, we analyze the influence of the strength parameter of perfect fluid DM on the destruction of the event horizon of a Kerr-like black hole with spinning after injecting a test particle and a scalar field. We find that, when a test particle is incident on the black hole, the event horizon is destroyed by perfect fluid dark matter for extremal black holes. For nearly extremal black holes, when the dark matter parameter satisfies $α\in \left (-r_{h} , 0\right ) \cup \left ( r_{h} ,k_2\right )$ i.e.$(A<0)$, the event horizon of the black hole will not be destroyed; when the dark matter parameter satisfies $α\in\left ( k_1 ,-r_{h} \right ]\cup \left[0,r_{h}\right ]$ i.e.$(A\ge 0)$, the event horizon of the black hole will be destroyed. When a classical scalar field is incident into the black hole in the extremal black hole case, we find that the range of mode patterns of the scalar field that can disrupt the black hole event horizon is different for different values of the perfect fluid dark matter strength parameter. In the nearly extremal black hole case, through our analysis, we have found when $α\neq0 $ and $α\neq\pm\ r_h$ i.e.$A\neq0$, the event horizon of the black hole can be disrupted. Our research results indicate that dark matter might be capable of breaking the black hole horizon, thus potentially violating the weak cosmic censorship conjecture.

gr-qc↗