35 papers
A Nonlocal Perfusion-Gated Angiogenesis System: Global Weak Solutions, Fast-Signal Limits, and Invasion Fronts
Jiguang Yu, Louis Shuo Wang
Continuum angiogenesis systems often use local endothelial or vessel density as an oxygen-delivery proxy without distinguishing structurally formed vessels from pressure-supported…
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…
Spatially Limited Immune Access Creates Tumour Refugia in Hepatocellular Carcinoma
Jiguang Yu, Louis Shuo Wang
Spatially restricted immune access can undermine tumour control even when total immune recruitment appears sufficient. We develop a nondimensional reaction--diffusion--chemotaxis m…
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…
Random Walk on Bézier Curves for Global Optimization
Jinpeng Wang, Xingguo Xu, Yujing Sun +3
Balancing exploration and exploitation remains a central challenge in metaheuristic optimization. To address this issue, this paper proposes Bézier Walk Evolution (BWE), a geometry…
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-…
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…
Elliptic criticality versus Volterra memory in indirect chemotaxis cascades
Louis Shuo Wang
Indirect signal production is often treated as a higher-order variant of classical Keller-Segel chemotaxis, but its critical structure depends strongly on how the signal cascade is…
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…
A Diagnostic Framework for Implementation Risk in Bilevel Decision Problems: The Ambiguity Premium and the Robustness--Efficiency Frontier
Jiguang Yu
Hierarchical decision problems are often modeled as bilevel programs in which a leader commits to a policy and a follower responds optimally. When the follower's optimal response i…
Controlling the Swarm: Sparse Actuation and Collision Avoidance under Stochastic Delay
Jiguang Yu
Classical flocking models demonstrate how local interactions generate emergent order, but real-world multi-agent deployments are bound by severe constraints: limited actuator avail…
Optimization Workshop Notes for Mathematical Programming with Equilibrium Constraints (MPECs): Second-Order Optimality Conditions
Jiguang Yu
In this workshop, we present a compact but rigorous introduction to second-order optimality conditions for mathematical programs with equilibrium constraints (MPECs). We start from…
Optimization Workshop Notes for Mathematical Programming with Equilibrium Constraints (MPECs): Verification of MPEC Hypotheses
Jiguang Yu
In this workshop, we present a compact but rigorous introduction to the basic language of nonlinear programming, variational inequalities, and complementarity systems. The goal is…
Optimization Workshop Notes for Mathematical Programming with Equilibrium Constraints Algorithms: Penalty Interior-Point, Implicit-Programming, and Piecewise SQP
Jiguang Yu
In this workshop, we discuss several algorithms for mathematical programs with equilibrium constraints (MPECs). The unifying theme is that MPECs are optimization problems whose fea…