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Youzhi Zhang

17 accepted papers

2026

Faster Parameter-Free Regret Matching Algorithms

ICLR 2026poster

Regret Matching (RM) and its variants are widely employed to learn a Nash equilibrium (NE) in large-scale games. However, most existing research only establishes a theoretical convergence rate of $O(1/\sqrt{T})$ for these algorithms in learning an NE. Recent studies have shown that smooth RM$^+$ var…

Cited by 0SourceScholar
2026

Tree-Based Stochastic Optimization for Solving Large-Scale Urban Network Security Games

AAAI 2026technical

Urban Network Security Games (UNSGs), which model the strategic allocation of limited security resources on city road networks, are critical for urban safety. However, finding a Nash Equilibrium (NE) in large-scale UNSGs is challenging due to their massive and combinatorial action spaces. One common

Cited by 0SourcePDFScholar
2025

Efficient Last-Iterate Convergence in Solving Extensive-Form Games

NeurIPS 2025poster

To establish last-iterate convergence for Counterfactual Regret Minimization (CFR) algorithms in learning a Nash equilibrium (NE) of extensive-form games (EFGs), recent studies reformulate learning an NE of the original EFG as learning the NEs of a sequence of (perturbed) regularized EFGs. Hence, pr…

Cited by 0SourcecodeScholar
2025

Last-Iterate Convergence of Smooth Regret Matching$^+$ Variants in Learning Nash Equilibria

NeurIPS 2025poster

Regret Matching$^+$ (RM$^+$) variants are widely used to build superhuman Poker AIs, yet few studies investigate their last-iterate convergence in learning a Nash equilibrium (NE). Although their last-iterate convergence is established for games satisfying the Minty Variational Inequality (MVI), no…

Cited by 0SourcecodeScholar
2025

Reducing Variance of Stochastic Optimization for Approximating Nash Equilibria in Normal-Form Games

ICML 2025spotlight

Nash equilibrium (NE) plays an important role in game theory. How to efficiently compute an NE in NFGs is challenging due to its complexity and non-convex optimization property. Machine Learning (ML), the cornerstone of modern artificial intelligence, has demonstrated remarkable empirical performanc…

Cited by 0SourcePDFScholar
2023

DUCK: A Drone-Urban Cyber-Defense Framework Based on Pareto-Optimal Deontic Logic Agents

AAAI 2023technical

Drone based terrorist attacks are increasing daily. It is not expected to be long before drones are used to carry out terror attacks in urban areas. We have developed the DUCK multi-agent testbed that security agencies can use to simulate drone-based attacks by diverse actors and develop a combinati…

Cited by 0SourcePDFScholar
2023

Solving Large-Scale Pursuit-Evasion Games Using Pre-trained Strategies

AAAI 2023technical

Pursuit-evasion games on graphs model the coordination of police forces chasing a fleeing felon in real-world urban settings, using the standard framework of imperfect-information extensive-form games (EFGs). In recent years, solving EFGs has been largely dominated by the Policy-Space Response Oracl…

Cited by 12SourcePDFScholar
2022

Correlation-Based Algorithm for Team-Maxmin Equilibrium in Multiplayer Extensive-Form Games

IJCAI 2022poster

Efficient algorithms computing a Nash equilibrium have been successfully applied to large zero- sum two-player extensive-form games (e.g., poker). However, in multiplayer games, computing a Nash equilibrium is generally hard, and the equilibria are not exchangeable, which makes players face the prob…

2021

CFR-MIX: Solving Imperfect Information Extensive-Form Games with Combinatorial Action Space

IJCAI 2021poster

In many real-world scenarios, a team of agents must coordinate with each other to compete against an opponent. The challenge of solving this type of game is that the team's joint action space grows exponentially with the number of agents, which results in the inefficiency of the existing algorithms,…

Cited by 12SourcePDFScholar
2021

Computing Ex Ante Coordinated Team-Maxmin Equilibria in Zero-Sum Multiplayer Extensive-Form Games

AAAI 2021technical

Computational game theory has many applications in the modern world in both adversarial situations and the optimization of social good. While there exist many algorithms for computing solutions in two-player interactions, finding optimal strategies in multiplayer interactions efficiently remains an…

Cited by 31SourcePDFScholar
2021

Solving Large-Scale Extensive-Form Network Security Games via Neural Fictitious Self-Play

IJCAI 2021poster

Securing networked infrastructures is important in the real world. The problem of deploying security resources to protect against an attacker in networked domains can be modeled as Network Security Games (NSGs). Unfortunately, existing approaches, including the deep learning-based approaches, are in…

Cited by 19SourcePDFScholar
2020

Learning Expensive Coordination: An Event-Based Deep RL Approach

ICLR 2020poster

Existing works in deep Multi-Agent Reinforcement Learning (MARL) mainly focus on coordinating cooperative agents to complete certain tasks jointly. However, in many cases of the real world, agents are self-interested such as employees in a company and clubs in a league. Therefore, the leader, i.e.,…

Cited by 11SourceScholar