Shaofei Chen

Shaofei Chen


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 May 2020 in IEEE Access
Verified
Journal Article
Open access
MLMeng-Lin Li
Meng-Lin Li
SCShaofei Chen
Shaofei Chen
JCJing Chen
Jing Chen
Multiagent systems (MASs) have received extensive attention in a variety of domains, such as robotics and distributed control. This paper focuses on how independent learners (ILs, structures used in decentralized reinforcement learning) decide on their individual behaviors to achieve coherent joint behavior. To date, Reinforcement learning(RL) approaches for ILs have not guaranteed convergence to the optimal joint policy in scenarios in which communication is difficult. Especially in a decentralized algorithm, the proportion of credit for a single agent’s action in a multiagent system is not distinguished, which can lead to miscoordination of joint actions. Therefore, it is highly significant to study the mechanisms of coordination between agents in MASs. Most previous coordination mechanisms have been carried out by modeling the communication mechanism and other agent policies. These methods are applicable only to a particular system, so such algorithms do not offer generalizability, especially when there are dozens or more agents. Therefore, this paper mainly focuses on the MAS contains more than a dozen agents. By combining the method of parallel computation, the experimental environment is closer to the application scene. By studying the paradigm of centralized training and decentralized execution(CTDE), a multi-agent reinforcement learning algorithm for implicit coordination based on TD error is proposed. The new algorithm can dynamically adjust the learning rate by deeply analyzing the dissonance problem in the matrix game and combining it with a multiagent environment. By adjusting the dynamic learning rate between agents, coordination of the agents’ strategies can be achieved. Experimental results show that the proposed algorithm can effectively improve the coordination ability of a MAS. Moreover, the variance of the training results is more stable than that of the hysteretic Q learning(HQL) algorithm. Hence, the problem of miscoordination in a MAS can be avoided to some extent without additional communication. Our work provides a new way to solve the miscoordination problem for reinforcement learning algorithms in the scale of dozens or more number of agents. As a new IL structure algorithm, our results should be extended and further studied.

18 June 2015 in PLOS ONE
Verified
Journal Article
Open access
PDF file
SCShaofei Chen
Shaofei Chen
FWFeng Wu
Feng Wu
LSLincheng Shen
Lincheng Shen
JCJing Chen
Jing Chen
Sarvapali D. RamchurnSarvapali D. Ramchurn
Sarvapali D. Ramchurn
We investigate a multi-agent patrolling problem where information is distributed alongside threats in environments with uncertainties. Specifically, the information and threat at each location are independently modelled as multi-state Markov chains, whose states are not observed until the location is visited by an agent. While agents will obtain information at a location, they may also suffer damage from the threat at that location. Therefore, the goal of the agents is to gather as much information as possible while mitigating the damage incurred. To address this challenge, we formulate the single-agent patrolling problem as a Partially Observable Markov Decision Process (POMDP) and propose a computationally efficient algorithm to solve this model. Building upon this, to compute patrols for multiple agents, the single-agent algorithm is extended for each agent with the aim of maximising its marginal contribution to the team. We empirically evaluate our algorithm on problems of multi-agent patrolling and show that it outperforms a baseline algorithm up to 44% for 10 agents and by 21% for 15 agents in large domains.

13 September 2023 in Electronics
Verified
Journal Article
Open access
PDF file
JCJiaxing Chen
Jiaxing Chen
WYWeilin Yuan
Weilin Yuan
SCShaofei Chen
Shaofei Chen
ZHZhenzhen Hu
Zhenzhen Hu
PLPeng Li
Peng Li
How to rapidly adapt to new tasks and improve model generalization through few-shot learning remains a significant challenge in meta-learning. Model-Agnostic Meta-Learning (MAML) has become a powerful approach, with offers a simple framework with excellent generality. However, the requirement to compute second-order derivatives and retain a lengthy calculation graph poses considerable computational and memory burdens, limiting the practicality of MAML. To address this issue, we propose Evolving MAML (Evo-MAML), an optimization-based meta-learning method that incorporates evolving gradient within the inner loop. Evo-MAML avoids the second-order information, resulting in reduced computational complexity. Experimental results show that Evo-MAML exhibits higher generality and competitive performance when compared to existing first-order approximation approaches, making it suitable for both few-shot learning and meta-reinforcement learning settings.

29 October 2022 in Electronics
Verified
Journal Article
Open access
PDF file
MZmingwo zou
mingwo zou
JCJing Chen
Jing Chen
JLJunren Luo
Junren Luo
ZHZhenzhen Hu
Zhenzhen Hu
SCShaofei Chen
Shaofei Chen
Satellite communication systems are increasingly facing serious environmental challenges such as malicious jamming, monitoring, and intercepting. As a current development of artificial intelligence, intelligent jammers with learning ability can effectively perceive the surrounding spectrum environment to dynamically change their jamming strategies. As a result, the current mainstream satellite communication anti-jamming technology based on wide interval high-speed frequency hopping is unable to deal with this problem effectively. In this work, we focus on anti-jamming problems in the satellite communication domain, and reformulate the power allocation problem under two kinds of confrontation scenarios as one-shot and repeated games model. Specifically, for the problem of multi-channel power allocation under a one-shot confrontation scenario, we firstly model the problem of allocating limited power resource between communication parties and a jammer on multi-channel based on a BG (Blotto Game) model. Secondly, a DO-SINR (Double Oracle-Signal to Interference plus Noise Ratio) algorithm is designed to approximate the Nash equilibrium of the game between two parties. Experiments show that the DO-SINR algorithm can effectively obtain the approximate Nash equilibrium of the game. For the problem of multi-channel power allocation under a repeated confrontation scenario, we firstly transform the problem into an online shortest path problem with a graph structure to make the problem solving process more intuitive, and then design the Exp3-U (Exp3-Uniform) algorithm which utilizes the graph structure to solve the multi-channel power allocation problem. Experiments show that our algorithm can minimize the expected regret of communication parties during online confrontation, while maintaining good operating efficiency. The two power allocation problems constructed in this paper are common problem formed in confrontation scenarios. Our research and analysis can simulate some actual confrontation scenarios of the satellite communication power allocation, which can be used to improve the adaptability of satellite communication systems in complex environments.

18 October 2021 in Electronics
Verified
Journal Article
Open access
PDF file
XJXiang Ji
Xiang Ji
WZWanpeng Zhang
Wanpeng Zhang
SCShaofei Chen
Shaofei Chen
JLJunren Luo
Junren Luo
LLLina Lu
Lina Lu
JCJing Chen
Jing Chen
This study addressed a problem of rapid velocity consensus within a swarm of unmanned aerial vehicles. Our analytical framework was based on tools using matrix theory and algebraic graph theory. We established connections between algebraic connectivity and the speed of converging on a velocity. The relationship between algebraic connectivity and communication cost was established. To deal with the trade-off among algebraic connectivity, convergence speed and communication cost, we propose a distributed small world network construction method. The small world network characteristics expedite the convergence speed toward consensus in the unmanned aerial vehicle swarm. Eventually, our method greatly sped up the consensus velocities in the unmanned aerial vehicle swarms at a lower communication cost than other methods required.

28 August 2021 in Electronics
Verified
Journal Article
Open access
PDF file
JXjiahui xu
jiahui xu
JCJing Chen
Jing Chen
SCShaofei Chen
Shaofei Chen
In the development of artificial intelligence (AI), games have often served as benchmarks to promote remarkable breakthroughs in models and algorithms. No-limit Texas Hold’em (NLTH) is one of the most popular and challenging poker games. Despite numerous studies having been conducted on this subject, there are still some important problems that remain to be solved, such as opponent exploitation, which means to adaptively and effectively exploit specific opponent strategies; this is acknowledged as a vital issue especially in NLTH and many real-world scenarios. Previous researchers tried to use an off-policy reinforcement learning (RL) method to train agents that directly learn from historical strategy interactions but suffered from challenges of sparse rewards. Other researchers instead adopted neuroevolutionary (NE) method to replace RL for policy parameter updates but suffered from high sample complexity due to the large-scale problem of NLTH. In this work, we propose NE_RL, a novel method combing NE with RL for opponent exploitation in NLTH. Our method contains a hybrid framework that uses NE’s advantage of evolutionary computation with a long-term fitness metric to address the sparse rewards feedback in NLTH and retains RL’s gradient-based method for higher learning efficiency. Experimental results against multiple baseline opponents have proved the feasibility of our method with significant improvement compared to previous methods. We hope this paper provides an effective new approach for opponent exploitation in NLTH and other large-scale imperfect information games.