Energy-aware decision-making for dynamic task migration in MEC-based unmanned aerial vehicle delivery system
CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE
Authors: Li, Rui; Li, Xuejun; Xu, Jia; Jiang, Frank; Jia, Zhaohong; Shao, Di; Pan, Lei; Liu, Xiao
Abstract
Nowadays, unmanned aerial vehicles (UAVs) are widely used in many smart systems such as smart logistics, smart agriculture, and environmental monitoring systems. However, the limited computing capability and restricted battery lifetime of existing UAVs could significantly impact the quality of service (QoS) of UAV-based smart systems and the quality of experience (QoE) of end users. Recently, Mobile Edge Computing (MEC) which provisions computing resources close to the mobile end devices has become a promising solution. However, since high-speed UAV often flies through the signal range of the different edge nodes, the interruption of services in the MEC-based UAV delivery system is a critical issue. A challenging question is when and how to perform dynamic task migration among the edge nodes to ensure service continuity. In this paper, we investigate the task migration issue for multiple UAVs in the MEC-based UAV delivery system. Specifically, we propose an energy-aware decision-making strategy for the dynamic task migration named GAD to optimize the UAV energy consumption. Given the real-time system status and QoS constraints, and through a dynamic two-tier decision-making mechanism, GAD can efficiently make the task migration decision from four candidate decisions, viz. No Migration, Data Migration Only, Cold Migration, and Live Migration. Experimental results based on a real-world scenario show that our strategy can well outperform other baseline strategies in various metrics including the flying distances and the energy consumption of UAVs.
Glutamic Acid Decarboxylase (GAD-65) Autoimmunity Associated With Profound Daytime Hypersomnia, Nighttime Insomnia, Mild Autonomic Neuropathy and Axonal Sensori-Motor Polyneuropathy: A Case Report on a New Phenotype
CUREUS
Authors: Kesserwani, Hassan
Abstract
We describe the case of a 74-year-old fit and healthy man who developed a profound sleep disorder characterized by mid-day hypersomnia and debilitating insomnia. A wide range of therapies, including a large number of stimulants and hypnotics with multiple different mechanisms of action, failed to improve his condition. Trials with oral prosthetic devices and a wide range of face masks with positive pressure assistance and multiple continuous positive airway pressure (CPAP) titration studies failed to help. Along with his sleep disorder, our patient developed a slowly evolving axonal sensorimotor polyneuropathy with a subtle autonomic neuropathy. Due to the latter two conditions, a comprehensive paraneoplastic panel was obtained and revealed extremely high titer glutamic acid decarboxylase (GAD-65) autoantibodies. This was confirmed by three independent laboratories and by cerebrospinal fluid staining of rat hippocampus, revealing the classic tram-track lines along the dentate gyrus. Our patient was treated empirically with intravenous immunoglobulin. We believe that our case reveals a unique syndrome related to GAD-65 autoantibodies and adds to the growing list of GAD- 65 associated diseases. This case is particularly provocative as it raises the idea to check for GAD- 65 autoimmunity in patients who suffer from a profound sleep disorder resistant to conventional treatment.