Tridiagonalization, which is a key step in symmetric eigenvalue decomposition (EVD), aims to convert a symmetric matrix to a tridiagonal form. In Nvidia's cuSOLVER library, the FP64 precision tridiagonalization process only reach 2.1 TFLOPs out of 67 TFLOPs on H100 GPU, and it consumes a significant portion of the elapsed time in the entire EVD process, accounting for over 97%. Thus, improving the tridiagonalization performance is crucial on accelerating EVD. In this paper, we analyze the reasons behind the suboptimal performance of tridiagonalization on GPU architectures, and we propose a new double blocking band reduction algorithm along with an implementation of GPU-based bulge chasing to improve the tridiagonalization performance. Through experimental evaluation, the proposed FP64 precision tridiagonalization method yields up to 19.6 TFLOPs which is 9.3x and 5.2x faster compared cuSOVLER and MAGMA, respectively.

Being an up-and-coming application scenario of mobile edge computing (MEC), the post-disaster rescue suffers multitudinous computing-intensive tasks but unstably guaranteed network connectivity. In rescue environments, quality of service (QoS), such as task execution delay, energy consumption and battery state of health (SoH), is of significant meaning. This paper studies a multi-user post-disaster MEC environment with unstable 5G communication, where device-to-device (D2D) link communication and dynamic voltage and frequency scaling (DVFS) are adopted to balance each user's requirement for task delay and energy consumption. A battery degradation evaluation approach to prolong battery lifetime is also presented. The distributed optimization problem is formulated into a mixed cooperative-competitive (MCC) multi-agent Markov decision process (MAMDP) and is tackled with recurrent multi-agent Proximal Policy Optimization (rMAPPO). Extensive simulations and comprehensive comparisons with other representative algorithms clearly demonstrate the effectiveness of the proposed rMAPPO-based offloading scheme.

Internet-of-Things (IoT) has played a critical role in developing sustainable smart cities and emerging numerous latency-sensitive IoT applications. Mobile edge computing (MEC) federation has the capability to incorporate a transparent resource management approach, which enables the sharing and utilization of MEC services from edge infrastructure providers (EIPs) and provides agile access services to mobile devices (MDs). In this paper, we investigate the joint optimization problem of computation offloading, task migration, and resource allocation in the MEC federation. The objective is to minimize the weighted sum of latency and energy consumption while maintaining load balancing under the constraint of the long-term migration cost budget of EIPs. To address the problem, we decompose it into two sub-problems: 1) the MDs clustering sub-problem and 2) the sub-problem of joint computation offloading, task migration, and resource allocation. Firstly, an MDs clustering matching (MDCM) algorithm is proposed to cluster the MDs in edge servers (ESs) according to the differences in channel gains. Afterward, the second sub-problem is simplified by the Lyapunov optimization technique, and then we propose a Transformer-based mobility prediction model and a decentralized deep deterministic policy gradient (DDPG)-based framework to solve it. Extensive simulation results demonstrate the cost-efficiency of the proposed algorithm.

Mobile edge computing (MEC) has emerged as a promising paradigm to enable computation-intensive and latency-sensitive mobile applications by offloading tasks to proximal edge servers. This paper proposes a novel federated reinforcement learning framework called Transformer-based Federated Soft Actor-Critic (TFSAC) to address a joint computation offloading and resource scheduling problem in a CPU-GPU heterogeneous MEC network while preserving privacy. Specifically, a graph attention network (GAT) extracts high-dimensional features from the task dependency graph. Rather than simply averaging weights, TFSAC applies transformer encoders to learn contextual relationships between agents and enable selective aggregation of relevant knowledge during federated model training to preserve agents’ privacy. Experiments on real-world trace data demonstrate TFSAC’s superiority over benchmarks in maximizing quality-of-service (QoS) across configurations.