Bounding the End-to-End Execution Time in Distributed Real-Time Systems: Arguing the case for Deterministic Networks in Lingua Franca

Designing and implementing distributed systems with real-time requirements quickly reveal the complexity of handling time and logic across multiple systems. As data traverse a network, it is subjected to variable delay due to interfering traffic and variable load on network components. This introduces an element of non-determinism in execution time for distributed algorithms, which translates into increased error logic and pessimistic worst-case estimates. Over the next few years, it is expected that Cyber-Physical Systems will see many new use cases, and the network connecting these will play an ever more important role. Combined with the onset of the fourth industrial revolution, IEEEs Time Sensitive Networking, IETFs Deterministic Networking, and 3GPPs Ultra Reliable Low Latency profile will play a vital role in realizing these systems. Coordination languages such as Lingua Franca can offer a substantial contribution to the design process and implementation of distributed systems such as Cyber-Phyiscal Systems, both through its model of computation which elevates time to a first-class citizen and with its support for distributed models. In this paper, we show that by introducing deterministic network channels with a fixed delay, the worst-case execution time is not increased whereas the variance in total execution time from start to finish is greatly reduced. For a coordination language such as LF, this means that we can analyze a system using much tighter delay bounds for network traffic, which in turn can yield better resource utilization.publishedVersio

Magnetic Field Energy Harvesting in Railway

Magnetic field energy harvesting (MFEH) is a method by which a system can harness an ambient, alternating magnetic field in order to scavenge energy. Presented in this article is a novel application of the concept aimed at the magnetic fields surrounding the rail current in electrified railway. Due to its noninvasive nature, the approach has the potential to be widely deployed as a part of low-cost trackside condition monitoring systems in order to increase lifetime and reduce maintenance requirements. In this article, the viability of MFEH in railway is substantiated experimentally—two different configurations are assessed both in a controlled laboratory environment as well as in situ along Norwegian railway. When placed near an emulated section of railway carrying 200 A in the laboratory, the power output of the system is up to 40.5 mW at 50 Hz and 4.15 mW at 16 23Hz . In the field, the prototype system harvests 109 mJ from a single freight train passing by, rendering an estimated daily energy output of 1.14 J in a moderately trafficked location. It is argued that the approach could indeed eliminate the need for battery replacements and potentially increase the lifetime of an energy-efficient, battery-powered condition monitoring system indefinitely.acceptedVersio

Sex Differences in Age-Related Loss of Kidney Function

Background - CKD is more prevalent in women, but more men receive kidney replacement therapy for kidney failure. This apparent contradiction is not well understood. Methods - We investigated sex differences in the loss of kidney function and whether any sex disparities could be explained by comorbidity or CKD risk factors. In the Renal Iohexol Clearance Survey (RENIS) in northern Europe, we recruited 1837 persons (53% women, aged 50–62 years) representative of the general population and without self-reported diabetes, CKD, or cardiovascular disease. Participants’ GFR was measured by plasma iohexol clearance in 2007–2009 (n=1627), 2013–2015 (n=1324), and 2018–2020 (n=1384). At each study visit, healthy persons were defined as having no major chronic diseases or risk factors for CKD. We used generalized additive mixed models to assess age- and sex-specific GFR decline rates. Results - Women had a lower GFR than men at baseline (mean [SD], 90.0 [14.0] versus 98.0 [13.7] ml/min per 1.73 m2; P2 per year in women and −1.20 (95% confidence interval [CI], −1.12 to −1.28) in men. Although the relationship between age and GFR was very close to linear in women, it was curvilinear in men, with steeper GFR slopes at older ages (nonlinear effect; P Conclusion - Among middle-aged and elderly individuals in the general population, decline in the mean GFR in women was slower than in men, independent of health status. CKD is projected to become the fifth leading cause of years of life lost in 2040. In most countries, more women than men develop CKD stage G3, which is defined as a reduced GFR, whereas more men start RRT. This apparent contradiction is poorly understood, but proposed explanations include gender disparities in access to health care and RRT, biologic differences between women and men leading to different GFR decline rates, bias in creatinine-based formulas to estimate the GFR, and overestimation of the CKD prevalence in women. In addition, sex and gender disparities in health status could cause differences in GFR loss. For example, women have a lower prevalence of myocardial infarction and a longer life expectancy than men. However, although cross-sectional population studies have found a higher mean GFR in healthy than in unhealthy persons, it is unknown whether good health is associated with preserved GFR during aging at the individual level, and whether this can explain the sex difference in CKD prevalence. Population-based longitudinal studies with repeated assessments of GFR in the same individuals are necessary to investigate the associations between sex, health status, and age-related GFR decline. The few existing studies on GFR change rates were not population based, did not investigate the association with health status, or used equations to calculate the eGFR on the basis of endogenous substances. These eGFR equations are biased by non–GFR-related factors, such as muscle mass, affecting men and women differently, particularly during aging. Measurements of GFR by an exogenous filtration marker, e.g., iohexol, avoid these methodologic problems. Accordingly, we investigated age- and sex-specific GFR decline rates in the Renal Iohexol Clearance Survey (RENIS), which is the only general population cohort with repeated measurements of GFR.The aim of the study was to report a reference range for age-related GFR decline in the general population and to investigate possible sex disparities in GFR decline rates by health status

net_chan: Deterministic network channels for distributed real-time systems

Network Channels (net_chan) is an open-source library that provides a network construct for deterministic channels between systems in distributed systems. net_chan is built to harness the Quality of Service guarantees offered by Time Sensitive Networking and the clock accuracy provided by the Precision Time Protocol. The software provides a simple and intuitive API for building distributed systems over packet-switched networks. When run on a system with a deterministic Linux kernel, the system provides an accurate synchronization mechanism between applications running on different hosts

A BUS PROTOCOL FOR INTERCOMPONENT COMMUNICATION IN ADVANCED UPPER-LIMB PROSTHESES

Microcontrollers are ubiquitous in modern electronic products, powered prosthetic components being no exception. Likewise, digital communication buses are the key technology for interconnecting such smart devices for reasons such as reduced wiring requirements, high information throughput, robustness in the presence of noise and flexibility. This flexibility contains the potential of interoperability, which means that similar components from different manufacturers may communicate in the same way so that one can easily be replaced by another or components from different manufacturers can be combined in one and the same system. However desirable this situation is, it requires an open, sandardised communication protocol that is adhered to by the majority of the manufacturers and research organisations. Presently no such standard exists in the prosthetics industry, while it has existed in related fields such as wheelchairs and environmental controllers for a number of years. In this paper we propose such a bus standard, and outline the potential benefits for end users, prosthetists and technicians, healthcare providers, manufacturers and researchers. We then list several important aspects of a prosthesis bus that must be carefully considered, and invite interested parties to engage in the completion of a draft specification

Technical Support Agreement for LAV TUA

This report describes the work carried out in the period January 2009 – February 2010 by SINTEF under the maintenance contract with NAMSA. Oppdragsgiver: NAMS

Technical Support Agreement for LAV TUA

-This report describes the work carried out in the period January 2009 – February 2010 by SINTEF under the maintenance contract with NAMSA. Oppdragsgiver: NAMS