32 papers
Smooth expanding planar simple waves for Euler--Poisson--Boltzmann: uniform stability and quasineutral expansion
Louis Shuo Wang, Jiguang Yu
We study the warm-ion Euler--Poisson system with Maxwell--Boltzmann electrons on the cylinder $\R\times\T$ in the quasineutral regime. Taking a smooth expanding planar simple wave…
Rigorous Analysis of a Nonlocal Transport--Renewal System for Physiologically Structured Populations
Jiguang Yu, Louis Shuo Wang, Ye Liang
We develop a rigorous analytical framework for a class of physiologically structured population models with two internal state variables, nonlocal ecological feedbacks, dynamic res…
FTU-Seek: Foundation Model-Guided Hard-Negative Learning for Sparse Functional Tissue Unit Segmentation
Zonghao Liu, Lei Su, Jiguang Yu +4
Functional tissue units (FTUs), including tertiary lymphoid structures (TLSs), blood vessels, and glands, encode localized immune, vascular, and epithelial organization in histopat…
Computational Oncology of Chemotaxis-Driven Tumour--Immune Spatial Patterning and Stability
Zonghao Liu, Jiguang Yu, Lei Su +3
We develop a reaction--diffusion--chemotaxis model for spatial tumour--immune--chemokine dynamics that couples logistic tumour growth, immune-mediated killing, chemokine-dependent…
Bilinear control of age--space structured populations
Jiguang Yu, Louis Shuo Wang, Ye Liang
We study constrained bilinear optimal control for nonlocal age--space structured population equations with renewal boundary conditions and endogenous surveillance feedback. The con…
A transport-only null model for apparent heterogeneity in diffusively dosed organoid arrays
Jiguang Yu, Louis Shuo Wang
Spatial transport can create apparent biological heterogeneity even when organoids are intrinsically identical. We develop a transport-to-phenotype null model for diffusively dosed…
From Flows to Maps: Sampling Laws for Attractor Intensity and Bounded-Noise Escape
Jiguang Yu, Louis Shuo Wang
Intensity of attraction quantifies the largest amplitude of a persistent bounded disturbance that an attractor can withstand without loss of controlled confinement in its basin. Al…
Optimal Harvesting of Size-Structured Populations with Environmental Feedback and Fixed Recruitment Flux
Louis Shuo Wang, Jiguang Yu
We study a nonlinear size-structured transport model with distributed harvesting and prescribed recruitment flux, where environmental feedback is determined by a scalar population…
Endogenous Feedback in Size-Structured Transport Equations
Jiguang Yu, Louis Shuo Wang
We study a nonlinear size-structured transport equation where the endogenous scalar output feeds back into velocity and mortality. This princi…
Fredholm--residue selection of the unsteady Kutta amplitude
Jiguang Yu, Louis Shuo Wang
We give an operator-theoretic interpretation of unsteady Kutta selection in trailing-edge acoustic receptivity. The inviscid acoustic--wake problem leaves one outgoing wake amplitu…
Vital-Rate Feedback and Threshold Harvesting in Size-Structured Populations
Louis Shuo Wang
Size-selective harvesting is often justified by the intuition that larger individuals have higher value and should therefore be harvested above a critical size. We study a controll…
A Measure-Valued Obstacle Problem for an Obliquely Reflected Diffusion with a Max-Type Payoff
Louis Shuo Wang, Jiguang Yu, Ye Liang
We study an obliquely reflected optimal stopping problem in the nonnegative quadrant with nonsmooth max-type payoff \(G(x)=x_1\veeαx_2\), and we develop a measure-valued potential-…
Time and Killed Resolvents in Reflected Optimal Stopping with a Max Payoff
Louis Shuo Wang, Ye Liang
We study infinite-horizon optimal stopping for normally reflected two-dimensional diffusions in the positive quadrant with max payoff \(G(x_1,x_2)=x_1\veeαx_2\). The non-smooth pay…
Killed resolvents and measure-valued stopping gains for reflected optimal stopping with max-type rewards
Louis Shuo Wang, Jiguang Yu, Ye Liang
We study an infinite-horizon optimal stopping problem for a normally reflected two-dimensional diffusion in the positive quadrant with nonsmooth max-type reward \(G(x_1,x_2)=x_1\ve…
Spectral perturbation theory for wall-admittance effects on compressible boundary-layer instability
Jiguang Yu, Louis Shuo Wang, Ye Liang
Thin wall treatments modify high-speed boundary-layer instability through the pressure they admit or absorb at the wall. This paper develops a unified admittance formulation for su…
Finite-sheeted Cauchy operator at rational corners
Louis Shuo Wang
We study Cauchy singular integral operators on planar wedges whose opening angle is a rational multiple of . For , the covering yields an exact finite-sheeted fa…
Nonsmooth Obstacles and Killed Resolvents in Reflected Stochastic Control
Louis Shuo Wang, Jiguang Yu
We study an infinite-horizon optimal stopping problem for a normally reflected two-dimensional diffusion in the quadrant with nonsmooth max-type payoff \(G(x_1,x_2)=x_1\veeαx_2\).…
Structural dichotomy and mass criticality in indirect chemotaxis cascades: fourth-order ellipticity versus Volterra memory
Jiguang Yu, Louis Shuo Wang
We investigate the structural and operator-theoretic foundations of indirect signal-generation mechanisms in Keller--Segel-type chemotaxis models. By analyzing a physically motivat…
First-Order Optimality Conditions for Mathematical Programming with Equilibrium Constraints
Louis Shuo Wang
We present a systematic introduction to first-order optimality conditions for mathematical programs with equilibrium constraints (MPECs), emphasizing the limitations of classical n…
Introduction to Exact Penalization for Mathematical Programming with Equilibrium Constraints
Louis Shuo Wang
We present a focused introduction to exact penalty methods for nonlinear programs and mathematical programs with equilibrium constraints (MPECs), emphasizing their connection to mo…
Introduction to Mathematical Programming with Equilibrium Constraints (MPECs) and Bilevel Optimization
Louis Shuo Wang
Our aim is to explain mathematical programs with equilibrium constraints (MPECs), motivate them through applications, present the main equivalent formulations of equilibrium constr…
Lecture Note for Bounded Controls in Continuous-Time and Control of Several Variables
Louis Shuo Wang
In this note, we develop the first-order theory of optimal control problems with box constraints on the control. We emphasize the precise modification of Pontryagin's maximum princ…
Size-Selective Threshold Harvesting under Nonlocal Crowding and Exogenous Recruitment
Jiguang Yu, Louis Shuo Wang, Ye Liang
We propose a nonlinear size-structured fishery model for externally recruited stocks under size-selective harvesting. The population density satisfies a McKendrick--von Foerster tr…
The Geometry of Quasi-Cycles: How Stoichiometric Covariance Alters Pre-Bifurcation Signatures
Louis Shuo Wang, Jiguang Yu, Ye Liang +1
Environmental enrichment can destabilize predator--prey coexistence through a Hopf bifurcation, yet real ecosystems are finite and intrinsically stochastic. We investigate how mech…