A score function for state of charge profiles for rechargeable batteries

We propose a new score function to compare and evaluate the relative impact of state-of-charge profiles on overall battery lifetime. Our score function, based on on a discrete Fourier transform of the state-of-charge profile, formalizes and generalizes earlier ideas found in the literature, and can form an important help in optimizing overall life time for battery powered systems. In this paper we introduce and illustrate the method, and discuss its merits as well as open issues and related literature

Mastering operational limitations of LEO satellites – The GOMX-3 approach

When working with space systems the keyword is resources. For a satellite in orbit all resources are sparse and the most critical resource of all is power. It is therefore crucial to have detailed knowledge on how much power is available for an energy harvesting satellite in orbit at every time – especially when in eclipse, where it draws its power from onboard batteries. This paper addresses this problem by a two-step procedure to perform task scheduling for low-earth-orbit (LEO) satellites exploiting formal methods. It combines cost-optimal reachability analyses of priced timed automata networks with a realistic kinetic battery model capable of capturing capacity limits as well as stochastic fluctuations. The procedure is in use for the automatic and resource-optimal day-ahead scheduling of GOMX-3, a power-hungry nanosatellite currently orbiting the earth. We explain how this approach has overcome existing problems, has led to improved designs, and has provided new insights

Clinical Outcome of Urgent Coronary Artery Bypass Grafting

Urgent coronary artery bypass grafting (CABG) has a higher mortality rate than elective CABG. The purpose of this study was to evaluate the clinical outcome of urgent CABG. From July 1992 to May 2005, 104 patients underwent urgent CABG. All patients required an urgent surgical revascularization within 24 hr of diagnostic coronary angiography. In-hospital mortality after urgent CABG was 17.3% (18/104). We compared preoperative characteristics and postoperative clinical outcomes between the survival group (n=86) and the mortality group (n=18). The mean age was 61.7 yr (range, 35-83). The most common cause of mortality was low cardiac output. The independent preoperative risk factors of mortality included advanced age (>70 yr) (OR=3.998, p=0.046), preoperative shock status (OR=6.542, p=0.011), and low ejection fraction (<40%) (OR=4.492, p=0.034). Other risk factors of mortality included prolonged cardiopulmonary bypass time, prolonged ventilator use, and extended intensive care unit stay. The 10-yr actuarial survival rate was 61%. Although the operative mortality rate was high after urgent CABG, a favorable long-term clinical outcome can be expected if the patients survive

An Overview of Verification and Validation Challenges for Inspection Robots

The advent of sophisticated robotics and AI technology makes sending humans into hazardous and distant environments to carry out inspections increasingly avoidable. Being able to send a robot, rather than a human, into a nuclear facility or deep space is very appealing. However, building these robotic systems is just the start and we still need to carry out a range of verification and validation tasks to ensure that the systems to be deployed are as safe and reliable as possible. Based on our experience across three research and innovation hubs within the UK’s “Robots for a Safer World” programme, we present an overview of the relevant techniques and challenges in this area. As the hubs are active across nuclear, offshore, and space environments, this gives a breadth of issues common to many inspection robot

Diabetes association with self-reported health, resource utilization, and prognosis post-myocardial infarction.

BACKGROUND: Diabetes mellitus (DM) is associated with increased cardiovascular (CV) risk. We compared health-related quality of life (HRQoL), healthcare resource utilization (HRU), and clinical outcomes of stable post-myocardial infarction (MI) patients with and without DM. HYPOTHESIS: In post-MI patients, DM is associated with worse HRQoL, increased HRU, and worse clinical outcomes. METHODS: The prospective, observational long-term risk, clinical management, and healthcare Resource utilization of stable coronary artery disease study obtained data from 8968 patients aged ≥50 years 1 to 3 years post-MI (369 centers; 25 countries). Patients with ≥1 of the following risk factors were included: age ≥65 years, history of a second MI >1 year before enrollment, multivessel coronary artery disease, creatinine clearance ≥15 and <60 mL/min, and DM treated with medication. Self-reported health status was assessed at baseline, 1 and 2 years and converted to EQ-5D scores. The main outcome measures were baseline HRQoL and HRU during follow-up. RESULTS: DM at enrollment was 33% (2959 patients, 869 insulin treated). Mean baseline EQ-5D score (0.86 vs 0.82; P < .0001) was higher; mean number of hospitalizations (0.38 vs 0.50, P < .0001) and mean length of stay (LoS; 9.3 vs 11.5; P = .001) were lower in patients without vs with DM. All-cause death and the composite of CV death, MI, and stroke were significantly higher in DM patients, with adjusted 2-year rate ratios of 1.43 (P < .01) and 1.55 (P < .001), respectively. CONCLUSIONS: Stable post-MI patients with DM (especially insulin treated) had poorer EQ-5D scores, higher hospitalization rates and LoS, and worse clinical outcomes vs those without DM. Strategies focusing specifically on this high-risk population should be developed to improve outcomes. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01866904 (https://clinicaltrials.gov)