arXiv subjects

Dan Lei

Publications and source records attributed to Dan Lei.

4 recordsLinked to original sources

arXiv2026

SeamEdit: A Black-Box VLM-Agnostic Pipeline for Large-Image Semantic Editing

Semantic region editing for large images must satisfy two requirements at the same time: high generative quality and natural integration with surrounding content. Some related methods rely on white-box models and leave the strong generation capability of closed-source models underexplored. Directly applying closed-source models to tiled editing, however, introduces several failure modes: semantic deformation, canvas-level alignment drift, and visible seam artifacts. This paper presents SeamEdit, a training-free and model-agnostic pipeline that treats any VLM with inpainting capability as a black-box oracle. SeamEdit mitigates these issues through a five-stage post-hoc pipeline: overlay-based tile decomposition, black-box VLM inpainting, geometric and color-consistency correction, seam-risk-based multi-candidate ranking, and dynamic-programming curved seam fusion. The pipeline reduces seam visibility and supports semantic modification of arbitrary tile regions.

cs.CV↗

arXiv2025

Nonlinear stability of a composite wave to the Cauchy problem of 1-D full compressible Navier-Stokes-Allen-Cahn system

The compressible Navier-Stokes-Allen-Cahn system models the motion of a mixture of two macroscopically immiscible viscous compressible fluids. In this paper, we are concerned with the large time behavior of solutions to the Cauchy problem of the one-dimensional full compressible Navier-Stokes-Allen-Cahn system. If the Riemann problem of the corresponding Euler system admits a solution which is a linear combination of 1-rarefaction wave and 3-rarefaction wave, we proved that a global strong solution to the compressible Navier-Stokes-Allen-Cahn system exists uniquely and converges to the above composite wave as time goes to infinity, provided that the adiabatic exponent $\gamma$ is closed to $1$. Here the initial perturbations except for the temperature function of the fluid, and the strength of rarefaction waves can be arbitrarily large. The proof is given by an elementary energy method that takes into account the effect of the phase field variable $\chi(t,x)$ and the complexity of nonlinear waves.

math.AP↗

arXiv2024

First-in-human spinal cord tumor imaging with fast adaptive focus tracking robotic-OCT

Current surgical procedures for spinal cord tumors lack in vivo high-resolution, high-speed multifunctional imaging systems, posing challenges for precise tumor resection and intraoperative decision-making. This study introduces the Fast Adaptive Focus Tracking Robotic Optical Coherence Tomography (FACT-ROCT) system,designed to overcome these obstacles by providing real-time, artifact-free multifunctional imaging of spinal cord tumors during surgery. By integrating cross-scanning, adaptive focus tracking and robotics, the system addresses motion artifacts and resolution degradation from tissue movement, achieving wide-area, high-resolution imaging. We conducted intraoperative imaging on 21 patients, including 13 with spinal gliomas and 8 with other tumors. This study marks the first demonstration of OCT in situ imaging of human spinal cord tumors, providing micrometer-scale in vivo structural images and demonstrating FACT-ROCT's potential to differentiate various tumor types in real-time. Analysis of the attenuation coefficients of spinal gliomas revealed increased heterogeneity with higher malignancy grades. So, we proposed the standard deviation of the attenuation coefficient as a physical marker, achieving over 90% accuracy in distinguishing high- from low-grade gliomas intraoperatively at a threshold. FACT-ROCT even enabled extensive in vivo microvascular imaging of spinal cord tumors, covering 70 mm * 13 mm * 10 mm within 2 minutes. Quantitative vascular tortuosity comparisons confirmed greater tortuosity in higher-grade tumors. The ability to perform extensive vascular imaging and real-time tumor grading during surgery provides critical information for surgical strategy, such as minimizing intraoperative bleeding and optimizing tumor resection while preserving functional tissue.

physics.optics↗

arXiv2023

All-optical correlated noisy channel and its application in recovering quantum coherence

Attenuation and amplification are the most common processes for optical communications. Amplification can be used to compensate the attenuation of the complex amplitude of an optical field, but is unable to recover the coherence lost, provided that the attenuation channel and the amplification channel are independent. In this work, we show that the quantum coherence of an optical filed can be regained if the attenuation channel and the amplification channel share correlated noise. We propose an all-optical correlated noisy channel relying on four-wave mixing process and demonstrate its capability of recovering quantum coherence within continuous-variable systems. We quantitatively investigate the coherence recovery phenomena for coherent states and two-mode squeezed states. Moreover, we analyze the effect of other photon losses that are independent with the recovery channel on the performance of recovering coherence. Different from correlated noisy channels previously proposed based on electro-optic conversions, the correlated noisy channel in our protocol is all-optical and thus owns larger operational bandwidths.

quant-ph↗