arXiv subjects

Mingyan Zhang

Publications and source records attributed to Mingyan Zhang.

5 recordsLinked to original sources

arXiv2026

A Coupling Method of Mixed and Lagrange Finite Elements for Linear Elasticity Problem

This paper proposes a finite element method that couples mixed and Lagrange finite elements to efficiently capture stress concentrations in elasticity problems. The method employs conforming mixed finite elements in regions with stress concentration, while standard Lagrange elements are used elsewhere, achieving a balance between stress accuracy and computational efficiency. The well-posedness of the coupled formulation and optimal a priori error estimates are established, even when the size of the mixed finite element subregion is $O(h)$. Numerical experiments are presented to verify the theoretical convergence rates and to demonstrate the effectiveness and efficiency of the proposed method.

math.NA↗

arXiv2026

Beyond Overlap Metrics: Rewarding Reasoning and Preferences for Faithful Multi-Role Dialogue Summarization

Multi-role dialogue summarization requires modeling complex interactions among multiple speakers while preserving role-specific information and factual consistency. However, most existing methods optimize for automatic metrics such as ROUGE and BERTScore, which favor surface-level imitation of references rather than genuine gains in faithfulness or alignment with human preferences. We propose a novel framework that couples explicit cognitive-style reasoning with reward-based optimization for multi-role dialogue summarization. Our method first distills structured reasoning traces (e.g., step-by-step inferences and intermediate reflections) from a large teacher model and uses them as auxiliary supervision to initialize a reasoning-aware summarizer via staged supervised fine-tuning. It then applies GRPO with a dual-principle reward that blends metric-based signals with human-aligned criteria targeting key information coverage, implicit inference, factual faithfulness, and conciseness. Experiments on multilingual multi-role dialogue benchmarks show that our method matches strong baselines on ROUGE and BERTScore. Specifically, results on CSDS confirm the framework's stability in semantic consistency, while in-depth analysis on SAMSum demonstrates clear gains in factual faithfulness and model-based preference alignment. These findings underscore the value of reasoning-aware and preference-aware training for reliable dialogue summarization. Checkpoints and datasets are available at https://huggingface.co/collections/NebulaPixel/summorchestra-multirole-summary.

cs.CL↗

arXiv2024

Off-site production of plasma-activated water for efficient sterilization: the crucial role of high-valence NOx and new chemical pathways

Efficient sterilization of pathogens with cleaner methods is a critical concern for environmental disinfection and clinical anti-infective treatment. Plasma-activated water (PAW) is a promising alternative to chemical disinfectants and antibiotics for its strong sterilization ability and not inducing any acute toxicity, and only water and air are consumed during production. For more efficient water activation, plasma sources are commonly placed near or fully in contact with water as possible, but the risks of electrode corrosion and metal contamination of water threaten the safety and stability of PAW production. Herein, plasma-activated gas rich in high-valence NOx is generated by a hybrid plasma configuration and introduced into water for off-site PAW production. Plasma-generated O3 is found to dominate the gas-phase reactions for the formation of high-valence NOx. With the time-evolution of O3 concentration, gaseous NO3 radicals are produced behind N2O5 formation, but will be decomposed before N2O5 quenching. By decoupling the roles of gaseous NO3, N2O5, and O3 in the water activation, results show that short-lived aqueous species induced by gaseous NO3 radicals play the most crucial role in PAW sterilization, and the acidic environment induced by N2O5 is also essential. Moreover, SEM photographs and biomacromolecule leakage assays demonstrate that PAW disrupts the cell membranes of bacteria to achieve inactivation. In real-life applications, an integrated device for off-site PAW production with a yield of 2 L/h and a bactericidal efficiency of >99.9% is developed. The PAW of 50mL produced in 3 minutes using this device is more effective in disinfection than 0.5% NaClO and 3% H2O2 with the same bacterial contact time. This work provides new avenues for efficient PAW production and deepens insights into the fundamental processes that govern the reactive chemistry in PAW sterilization.

physics.plasm-ph↗

arXiv2023

Unfitted finite element method for the quad-curl interface problem

In this paper, we introduce a novel unfitted finite element method to solve the quad-curl interface problem. We adapt Nitsche's method for curlcurl-conforming elements and double the degrees of freedom on interface elements. To ensure stability, we incorporate ghost penalty terms and a discrete divergence-free term. We establish the well-posedness of our method and demonstrate an optimal error bound in the discrete energy norm. We also analyze the stiffness matrix's condition number. Our numerical tests back up our theory on convergence rates and condition numbers.

math.NA↗

arXiv2023

Fully H(gradcurl)-nonconforming Finite Element Method for The Singularly Perturbed Quad-curl Problem on Cubical Meshes

In this paper, we develop two fully nonconforming (both H(grad curl)-nonconforming and H(curl)-nonconforming) finite elements on cubical meshes which can fit into the Stokes complex. The newly proposed elements have 24 and 36 degrees of freedom, respectively. Different from the fully H(grad curl)-nonconforming tetrahedral finite elements in [9], the elements in this paper lead to a robust finite element method to solve the singularly perturbed quad-curl problem. To confirm this, we prove the optimal convergence of order $O(h)$ for a fixed parameter $ε$ and the uniform convergence of order $O(h^{1/2})$ for any value of $ε$. Some numerical examples are used to verify the correctness of the theoretical analysis.

math.NA↗