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Cyber-physical systems (CPS) increasingly require real-time, high bandwidth data communication and processing. To address this, Time Sensitive Networking (TSN) provides latency-bounded data trans- mission at one or more gigabits-per-second throughput. However, it does not commonly connect directly to I/O devices, such as sensors and ac- tuators. In contrast, Universal Serial Bus (USB) is ubiquitous for device I/O, but has yet to be widely adopted for host-to-host networking. This paper considers the use of a common USB software stack for both device I/O and host-to-host communication. We compare against a sys- tem using USB for device I/O and TSN for host-level networking. Our findings show that a unified approach using USB results in reduced soft- ware complexity, simplified bus coordination, and more effective miti- gation of priority inversion when transferring data across multiple bus segments. Experiments show that end-to-end latency is within expected delay bounds, and is reduced if the same USB software stack is used for all communication with a given host. This suggests that bridging chal- lenges exist in current systems, which are solved by either extending a high-bandwidth bus such as TSN to support device I/O, or enhancing USB with improved networking capabilities. 

Cyber-physical systems (CPS) increasingly require real-time, high bandwidth data communication and processing. To address this, Time Sensitive Networking (TSN) provides latency-bounded data transmission at one or more gigabits-per-second throughput. However, it does not commonly connect directly to I/O devices, such as sensors and actuators. In contrast, Universal Serial Bus (USB) is ubiquitous for device I/O, but has yet to be widely adopted for host-to-host networking. This paper considers the use of a common USB software stack for both device I/O and host-to-host communication. We compare against a system using USB for device I/O and TSN for host-level networking. Our findings show that a unified approach using USB results in reduced software complexity, simplified bus coordination, and more effective mitigation of priority inversion when transferring data across multiple bus segments. Experiments show that end-to-end latency is within expected delay bounds, and is reduced if the same USB software stack is used for all communication with a given host. This suggests that bridging challenges exist in current systems, which are solved by either extending a high-bandwidth bus such as TSN to support device I/O, or enhancing USB with improved networking capabilities. 

We show that metric trees and their products meet the octahedron comparison, which is a certain six-point metric comparison similar to Alexandrov’s CAT(0) comparison. 

Abstract Initial orbit determination (IOD) from line-of-sight (i.e., bearing) measurements is a classical problem in astrodynamics. Indeed, there are many well-established methods for performing the IOD task when given three line-of-sight observations at known times. Interestingly, and in contrast to these existing methods, concepts from algebraic geometry may be used to produce a purely geometric solution. This idea is based on the fact that bearings from observers in general position may be used to directly recover the shape and orientation of a three-dimensional conic (e.g., a Keplerian orbit) without any need for knowledge of time. In general, it is shown that five bearings at unknown times are sufficient to recover the orbit—without the use of any type of initial guess and without the need to propagate the orbit. Three bearings are sufficient for purely geometric IOD if the orbit is known to be (approximately) circular. The method has been tested over different scenarios, including one where extra observations make the system of equations over-determined. 

Devices made from thin films of halide perovskites are advancing due to their potential in photovoltaic and optoelectronic applications, largely attributed to their energy level tunability, which can be achieved...