arXiv subjects

Zhiping Li

Publications and source records attributed to Zhiping Li.

13 recordsLinked to original sources

arXiv2026

GMPilot: An Expert AI Agent For FDA cGMP Compliance

The pharmaceutical industry is facing challenges with quality management such as high costs of compliance, slow responses and disjointed knowledge. This paper presents GMPilot, a domain-specific AI agent that is designed to support FDA cGMP compliance. GMPilot is based on a curated knowledge base of regulations and historical inspection observations and uses Retrieval-Augmented Generation (RAG) and Reasoning-Acting (ReAct) frameworks to provide real-time and traceable decision support to the quality professionals. In a simulated inspection scenario, GMPilot shows how it can improve the responsiveness and professionalism of quality professionals by providing structured knowledge retrieval and verifiable regulatory and case-based support. Although GMPilot lacks in the aspect of regulatory scope and model interpretability, it is a viable avenue of improving quality management decision-making in the pharmaceutical sector using intelligent approaches and an example of specialized application of AI in highly regulated sectors.

cs.AI↗

arXiv2026

Solving Chance Constrained Programs via a Penalty based Difference of Convex Approach

We develop two penalty based difference of convex (DC) algorithms for solving chance constrained programs. First, leveraging a rank-based DC decomposition of the chance constraint, we propose a proximal penalty based DC algorithm in the primal space that does not require a feasible initialization. Second, to improve numerical stability in the general nonlinear settings, we derive an equivalent lifted formulation with complementary constraints and show that, after minimizing primal variables, the penalized lifted problem admits a tractable DC structure in the dual space over a simple polyhedron. We then develop a penalty based DC algorithm in the lifted space with a finite termination guarantee. We establish exact penalty and stationarity guarantees under mild constraint qualifications and identify the relationship of the local minimizers between the two formulations. Numerical experiments demonstrate the efficiency and effectiveness of our proposed methods compared with state-of-the-art benchmarks.

math.OC↗

arXiv2025

An Alternating Direction Method of Multipliers for Utility-based Shortfall Risk Portfolio Optimization

Utility-based shortfall risk (UBSR), a convex risk measure sensitive to tail losses, has gained popularity in recent years. However, research on computational methods for UBSR optimization remains relatively scarce. In this paper, we propose a fast and scalable algorithm for the UBSR-based portfolio optimization problem. Leveraging the Sample Average Approximation (SAA) framework, we reformulate the problem as a block-separable convex program and solve it efficiently via the alternating direction method of multipliers (ADMM). In the high-dimensional setting, a key challenge arises in one of the subproblems -- a projection onto a nonlinear feasibility set defined by the shortfall-risk constraint. We propose two semismooth Newton algorithms to solve this projection subproblem. The first algorithm directly applies a semismooth Newton iteration to the Karush-Kuhn-Tucker (KKT) system of the projection problem. The second algorithm employs an implicit function transformation of semismooth functions to reduce the problem to a univariate equation involving the Lagrange multiplier and achieves global superlinear convergence with enhanced numerical stability under mild regularity conditions. Theoretical convergence guarantees of the proposed algorithms are established, and numerical experiments demonstrate a substantial speedup over state-of-the-art solvers, particularly in high-dimensional regimes.

math.OC↗

arXiv2025

Multi-Branch Collaborative Learning Network for Video Quality Assessment in Industrial Video Search

Video Quality Assessment (VQA) is vital for large-scale video retrieval systems, aimed at identifying quality issues to prioritize high-quality videos. In industrial systems, low-quality video characteristics fall into four categories: visual-related issues like mosaics and black boxes, textual issues from video titles and OCR content, and semantic issues like frame incoherence and frame-text mismatch from AI-generated videos. Despite their prevalence in industrial settings, these low-quality videos have been largely overlooked in academic research, posing a challenge for accurate identification. To address this, we introduce the Multi-Branch Collaborative Network (MBCN) tailored for industrial video retrieval systems. MBCN features four branches, each designed to tackle one of the aforementioned quality issues. After each branch independently scores videos, we aggregate these scores using a weighted approach and a squeeze-and-excitation mechanism to dynamically address quality issues across different scenarios. We implement point-wise and pair-wise optimization objectives to ensure score stability and reasonableness. Extensive offline and online experiments on a world-level video search engine demonstrate MBCN's effectiveness in identifying video quality issues, significantly enhancing the retrieval system's ranking performance. Detailed experimental analyses confirm the positive contribution of all four evaluation branches. Furthermore, MBCN significantly improves recognition accuracy for low-quality AI-generated videos compared to the baseline.

cs.CV↗

arXiv2020

Study on the anti-correlated painting injection scheme for the Rapid Cycling Synchrotron of the China Spallation Neutron Source

In the rapid cycling synchrotron of the China Spallation Neutron Source, the anti-correlated painting was adopted for the design scheme of the injection system. In the beam commissioning, with the optimization of the anti-correlated painting,the injection beam loss has been well controlled and the injection efficiency has exceeded 99%. Combined with other aspects of adjustments, the beam power on the target has reached 50 kW smoothly. In this paper, we have studied the injection optimization in the beam commissioning. Compared to the simulation results of the design scheme, the transverse beam distribution, transverse coupling effect and beam loss of the anti-correlated painting in the beam commissioning are somewhat different. Through the machine studies, we have carefully analyzed these differences and studied their reasons.

physics.acc-ph↗

arXiv2019

Design and Realization of a Reflectarray Compact Antenna Test Range

This paper presents a reflectarray compact antenna test range (RACATR). The new range layout is designed to suppress the unwanted diffraction. A fast near field optimization method has been used to determine the phase distribution of the only phased aperture efficiently in numerical example. The full wave simulation results of the linear reflectarray support that this facility design approach is working well to suppress the structural interference such as the mirror reflection and the edge diffraction. A 460 mm,460 mm square reflectarray was manufactured and measured. Satisfying the requirement of the quiet zone field distribution, the quasi-plane wave is achieved from 26.5~28.5 GHz by linearly adjusting the feed location.

eess.SP↗

arXiv2018

A Mixed Finite Element Method for Multi-Cavity Computation in Incompressible Nonlinear Elasticity

A mixed finite element method combining an iso-parametric $Q_2$-$P_1$ element and an iso-parametric $P_2^+$-$P_1$ element is developed for the computation of multiple cavities in incompressible nonlinear elasticity. The method is analytically proved to be locking-free and convergent, and it is also shown to be numerically accurate and efficient by numerical experiments. Furthermore, the newly developed accurate method enables us to find an interesting new bifurcation phenomenon in multi-cavity growth.

math.AP↗

arXiv2017

A Locking-free DP-Q2-P1 MFEM for Incompressible Nonlinear Elasticity Problems

A mixed finite element method (MFEM), using dual-parametric piecewise bi-quadratic and affine (DP-Q2-P1) finite element approximations for the deformation and the pressure like Lagrange multiplier respectively, is developed and analyzed for the numerical computation of incompressible nonlinear elasticity problems with large deformation gradient, and a damped Newton method is applied to solve the resulted discrete problem. The method is proved to be locking free and stable. The accuracy and efficiency of the method are illustrated by numerical experiments on some typical cavitation problems.

math.AP↗

arXiv2017

A Fourier-Chebyshev Spectral Method for Cavitation Computation in Nonlinear Elasticity

A Fourier-Chebyshev spectral method is proposed in this paper for solving the cavitation problem in nonlinear elasticity. The interpolation error for the cavitation solution is analyzed, the elastic energy error estimate for the discrete cavitation solution is obtained, and the convergence of the method is proved. An algorithm combined a gradient type method with a damped quasi-Newton method is applied to solve the discretized nonlinear equilibrium equations. Numerical experiments show that the Fourier-Chebyshev spectral method is efficient and capable of producing accurate numerical cavitation solutions.

math.NA↗

arXiv2017

A Meshing Strategy for a Quadratic Iso-parametric FEM in Cavitation Computation in Nonlinear Elasticity

The approximation properties of a quadratic iso-parametric finite element method for a typical cavitation problem in nonlinear elasticity are analyzed. More precisely, (1) the finite element interpolation errors are established in terms of the mesh parameters; (2) a mesh distribution strategy based on an error equi-distribution principle is given; (3) the convergence of finite element cavity solutions is proved. Numerical experiments show that, in fact, the optimal convergence rate can be achieved by the numerical cavity solutions.

math.NA↗

arXiv2016

Orientation-Preservation Conditions on an Iso-parametric FEM in Cavitation Computation

The orientation-preservation condition, i.e., the Jacobian determinant of the deformation gradient $\det \nabla u$ is required to be positive, is a natural physical constraint in elasticity as well as in many other fields. It is well known that the constraint can often cause serious difficulties in both theoretical analysis and numerical computation, especially when the material is subject to large deformations. In this paper, we derive a set of sufficient and necessary conditions for the quadratic iso-parametric finite element interpolation functions of cavity solutions to be orientation preserving on a class of radially symmetric large expansion accommodating triangulations. The result provides a practical quantitative guide for meshing in the neighborhood of a cavity and shows that the orientation-preservation can be achieved with a reasonable number of total degrees of freedom by the quadratic iso-parametric finite element method.

math.NA↗

arXiv2013

The Study on the Effects of Chromaticity and Magnetic Field Tracking Errors at CSNS/RCS

The Rapid Cycling Synchrotron (RCS) is a key component of the China Spallation Neutron Source (CSNS). For this type of high intensity proton synchrotron, the chromaticity, space charge effects and magnetic field tracking errors between the quadrupoles and the dipoles can induce beta function distortion and tune shift, and induce resonances. In this paper the combined effects of chromaticity, magnetic field tracking errors and space charge on beam dynamics at CSNS/RCS are studied systemically. 3-D simulations with different magnetic field tracking errors are performed by using the code ORBIT, and the simulation results are compared with the case without tracking errors.

physics.acc-ph↗

arXiv2013

Quantum resonance scheme to determine the gravitational constant G

Building on the principles of quantum electrodynamics and special relativity, we develop a semi-classical QED theory of gravitation. The experiment model for theoretical analysis is the "hyperfine splitting" of the ground energy state of hydrogen atoms. As the verification and validation by Newton's final experiment, Newton's gravity constant G has been determined by this new approach, G = 6.67221937(40)*10^(-11) N m2 /kg2. The result shows that, the gravitational constant G is really a universal constant in free space, and can be determined just by the more fundamental constants in physics.

physics.gen-ph↗