arXiv subjects

M. Maurice

Publications and source records attributed to M. Maurice.

3 recordsLinked to original sources

arXiv2024

Gl 725A b: a potential super-Earth detected with SOPHIE and SPIRou in an M dwarf binary system at 3.5 pc

We report the discovery of a super-Earth candidate orbiting the nearby mid M dwarf Gl\,725A using the radial velocity (RV) method. The planetary signal has been independently identified using high-precision RVs from the SOPHIE and SPIRou spectrographs, in the optical and near-infrared domains, respectively. We modelled the stellar activity signal jointly with the planet using two Gaussian Processes, one for each instrument to account for the chromaticity of the stellar activity and instrumental systematics, along with a Keplerian model. The signal is significantly detected with a RV semi-amplitude of $1.67\pm0.20$ m/s. The planet Gl 725A b is found to be in an orbit compatible with circular with a period of $11.2201\pm0.0051$ days. We analysed 27 sectors of TESS photometry on which no transit event was found. We determined a minimum mass of $M_{p}\sin{i}=2.78\pm0.35\,M_{\oplus}$ which places the planet in the super-Earth regime. Using Mass-Radius relationships we predict a planetary radius to be between 1.2 and $2.0\,R_{\oplus}$. The proximity of Gl 725A, of only 3.5 pc, makes this new exoplanet one of the closest to Earth and joins the group of S-type low-mass planets in short orbits ($P<15$ d) around close M dwarfs.

astro-ph.EP↗

arXiv2022

EdgeKeeper: Resilient and Lightweight Coordination for Mobile Edge Computing Systems

Mobile Edge Computing (MEC) has been gaining significant interest from first responders and tactical teams, primarily because they can employ handheld mobile devices to form a computing cluster (for computing tasks like face/scene recognition, virtual assistance) when connectivity to the cloud is not present or it is limited. High user mobility in first responder or tactical environments makes MEC challenging, as wireless links observe substantial fluctuations. Typical cloud-based coordination (e.g., ZooKeeper-based service discovery and coordination, device naming, security) needed by edge computing tasks cannot work in these environments. Driven by the need for a resilient and lightweight coordination service, in this paper, we design and implement \ek to provide cloud-like coordination for MEC systems. It provides naming, network management, application coordination, and security to distributed edge computing applications. It maintains an edge cluster among devices and intelligently stores its data on a group of replicas to guard against node failure and disconnections. We provide a full-system implementation of EdgeKeeper for Android and Linux platforms. We have integrated EdgeKeeper with existing MEC applications and performed real-world performance evaluations in a wide-area search and rescue operation conducted by first responders, which proves it to be lightweight and suitable for mobile devices.

cs.DC↗

arXiv2022

R-Drive: Resilient Data Storage and Sharing for Mobile Edge Computing Systems

Mobile edge computing (MEC) systems (in which intensive computation and data storage tasks are performed locally, due to the absence of communication infrastructure for connectivity to the cloud) are currently being developed for disaster response applications and for tactical environments. MEC applications for these scenarios generate and process significant mission-critical and personal data that require resilient and secure storage and sharing. In this paper, we present the design, implementation, and evaluation of R-Drive, a resilient data storage and sharing framework for disaster response and tactical MEC applications. R-Drive employs erasure coding and data encryption, ensuring resilient and secure data storage against device failure. R-Drive adaptively chooses erasure coding parameters to ensure the highest data availability with a minimal storage cost. R-Drive's distributed directory service provides a resilient and secure namespace for files with rigorous access control management. R-Drive leverages opportunistic networking, allowing data storage and sharing in mobile and loosely connected edge computing environments. We implemented R-Drive on Android, and integrated it with existing MEC applications. Performance evaluation results show that R-Drive enables resilient and secure data storage and sharing.

cs.DC↗