Industrial Application of a Partitioning Scheduler to Support Mixed Criticality Systems

The ever-growing complexity of safety-critical control systems continues to require evolution in control system design, architecture and implementation. At the same time the cost of developing such systems must be controlled and importantly quality must be maintained. This paper examines the application of Mixed Criticality System (MCS) research to a DAL-A aircraft engine Full Authority Digital Engine Control (FADEC) system which includes studying porting the control system\u27s software to a preemptive scheduler from a non-preemptive scheduler. The paper deals with three key challenges as part of the technology transitions. Firstly, how to provide an equivalent level of fault isolation to ARINC 653 without the restriction of strict temporal slicing between criticality levels. Secondly extending the current analysis for Adaptive Mixed Criticality (AMC) scheduling to include the overheads of the system. Finally the development of clustering algorithms that automatically group tasks into larger super-tasks to both reduce overheads whilst ensuring the timing requirements, including the important task transaction requirements, are met

Estimating local car ownership models

Many studies in the transport demand literature have shown that income is an important factor in determining how many cars a household owns. When the models used to measure the strength of this relationship are estimated on cross-sectional data, they typically yield one overall value as the estimate. Local circumstances will, however, vary. This paper illustrates the use of the Geographically Weighted Regression technique to estimate the individual strength of this relationship for each of the United Kingdom electoral wards. Use of this type of model enables a wards’ income elasticity to be based on both the local estimate of the strength of this relationship and the current local level of car ownership. How the use of this local elasticity changes future forecasts of the size of the vehicle fleet is illustrated

Use of administrative data for the surveillance of mental disorders in 5 provinces

To evaluate the usefulness of administrative data for the surveillance of mental illness in Canada using databases in the following 5 provinces: British Columbia, Ontario, Quebec, Nova Scotia, and Alberta. We used a population-based record-linkage analysis with data from physician billings, hospital discharge abstracts, and community-based clinics. The following diagnostic codes from the International Classification of Diseases, Ninth Edition, were used to define cases: 290 to 319, inclusive. The prevalence of treated psychiatric disorder was similar in Nova Scotia, British Columbia, Alberta, and Ontario at about 15%. The prevalence for Quebec was slightly lower at 12%. Findings from the provinces showed remarkable consistency across age and sex, despite variations in data coding. Women tended to show a higher prevalence overall of treated mental disorders than men. Prevalence increased steadily to middle age, declining in the 50s and 60s, and then increasing again after age 70 years. Provincial and territorial administrative data can provide a useful, reliable, and economical source of information for the surveillance of treated mental disorders. Such a surveillance system can provide longitudinal data at little cost to support health service provision and planning

A surveillance system to monitor excess mortality of people with mental illness in Canada

Objective: Outcome measures are rarely available for surveillance and system performance monitoring for mental disorders and addictions. Our study aims to demonstrate the feasibility and face validity of routinely measuring the mortality gap in the Canadian context at the provincial and regional levels using the methods and data available to the Canadian Chronic Disease Surveillance System (CCDSS) of the Public Health Agency of Canada. Methods: We used longitudinal data from the Quebec Integrated Chronic Disease Surveillance System, which also provides aggregated data to the CCDSS. This includes data from the health insurance registry physician claims and the hospital discharge abstract for all mental disorder diagnoses (International Classification of Diseases [ICD]-9 290-319 or ICD-10 F00-F99). Patients were defined as having had received a mental disorder diagnosis at least once during the year. Life expectancy was measured using Chiang's method for abridged life tables, complemented by the Hsieh method for adjustment of the last age interval. Results: We found a lower life expectancy among psychiatric patients of 8 years for men and 5 years for women. For patients with schizophrenia, life expectancy was lowered by 12 years for men and 8 years for women. Cardiovascular disease and cancer were the most common causes of premature death. Findings were consistent across time and regions of the province. Lower estimates of the mortality gap, compared with literature, could be explained by the inclusion of primary care patients and methods. Conclusions: Our study demonstrates the feasibility of using administrative data to measure the impact of current and future mental health plans in Canada provided the techniques can be replicated in other Canadian provinces

IL23R (Interleukin 23 Receptor) variants protective against inflammatory bowel diseases (IBD) display loss of functiondue to impaired protein stability and intracellular trafficking

Genome-wide association studies as well as murine models have shown that the interleukin 23 receptor (IL23R) pathway plays a pivotal role in chronic inflammatory diseases such as Crohn disease (CD), ulcerative colitis, psoriasis, and type 1 diabetes. Genome-wide association studies and targeted re-sequencing studies have revealed the presence of multiple potentially causal variants of the IL23R. Specifically the G149R, V362I, and R381Q IL23R chain variants are linked to protection against the development of Crohn disease and ulcerative colitis in humans. Moreover, the exact mechanism of action of these receptor variants has not been elucidated. We show that all three of these IL23R variants cause a reduction in IL23 receptor activation-mediated phosphorylation of the signaltransducing activator of transcription 3 (STAT3) and phosphorylation of signal transducing activator of transcription 4 (STAT4). The reduction in signaling is due to lower levels of cell surface receptor expression. For G149R, the receptor retention in the endoplasmic reticulum is due to an impairment of receptor maturation, whereas the R381Q and V362I variants have reduced protein stability. Finally, we demonstrate that the endogenous expression of IL23R protein from V362I and R381Q variants in human lymphoblastoid cell lines exhibited lower expression levels relative to susceptibility alleles. Our results suggest a convergent cause of IL23R variant protection against chronic inflammatory disease

Industrial Application of a Partitioning Scheduler to Support Mixed Criticality Systems

The ever-growing complexity of safety-critical control systems continues to require evolution in control system design, architecture and implementation. At the same time the cost of developing such systems must be controlled and importantly quality must be maintained. This paper examines the application of Mixed Criticality System (MCS) research to a DAL-A aircraft engine Full Authority Digital Engine Control (FADEC) system which includes studying porting the control system’s software to a preemptive scheduler from a non-preemptive scheduler. The paper deals with three key challenges as part of the technology transitions. Firstly, how to provide an equivalent level of fault isolation to ARINC 653 without the restriction of strict temporal slicing between criticality levels. Secondly extending the current analysis for Adaptive Mixed Criticality (AMC) scheduling to include the overheads of the system. Finally the development of clustering algorithms that automatically group tasks into larger super-tasks to both reduce overheads whilst ensuring the timing requirements, including the important task transaction requirements, are met

TACO: : An industrial case study of Test Automation for COverage

Timing analysis is an important part of the development of critical real-time systems. It stems from the need to provide evidence on the behaviour of the system, compliance to requirements and timing bounds. The formal testing process is complicated, and includes tests to achieve compliance with certification requirements. Where possible, testing should be performed on a host and then validated on the target. This is especially important for real systems where the target may not be available early in the project or target-based testing is expensive and time consuming. Meaningful host-based testing is difficult when it comes to timing analysis. Automation helps reduce the costs and move testing earlier in the application development cycle. Moving testing earlier in the development cycle not only enables the testing to scale to whole systems, it allows the risks of projects to be managed and software to be optimised before target-based testing is performed. In this paper, we extend existing work achieving reliable coverage and High WaterMark (HWM) measurement, to scale its application to the analysis of a full system software build, automate the test process, and minimise the set of tests deployed on target. Our case study demonstrates the successful application of the approach on a large code base, i.e. an existing controls system software code. The paper ends with a position statement about how this work is instrumental for both future research but also as part of industry practically analysing the timing behaviour of systems automatically and certifying mixed-criticality systems

Shot Noise in Mesoscopic Conductors

Theoretical and experimental work concerned with dynamic fluctuations has developed into a very active and fascinating subfield of mesoscopic physics. We present a review of this development focusing on shot noise in small electric conductors. Shot noise is a consequence of the quantization of charge. It can be used to obtain information on a system which is not available through conductance measurements. In particular, shot noise experiments can determine the charge and statistics of the quasiparticles relevant for transport, and reveal information on the potential profile and internal energy scales of mesoscopic systems. Shot noise is generally more sensitive to the effects of electron-electron interactions than the average conductance. We present a discussion based on the conceptually transparent scattering approach and on the classical Langevin and Boltzmann-Langevin methods; in addition a discussion of results which cannot be obtained by these methods is provided. We conclude the review by pointing out a number of unsolved problems and an outlook on the likely future development of the field.Comment: 99 two-column pages; 38 .eps figures included. Submitted to Physics Reports. Many minor improvements; typos corrected; references added and update

Time trends in mortality associated with depression: findings from the Stirling County study

OBJECTIVE: to address the question of whether a mortality risk associated with depression in a 1952 representative sample of Stirling County adults changed in a new sample in 1970, and whether there was a change in associations with cigarette smoking and alcoholism. METHOD: sample members were interviewed about depression and cigarette smoking. General physicians were interviewed by psychiatrists regarding alcoholism. Information about death as of December 31, 1992, was provided by Statistics Canada. Proportional hazards models were fitted in the 2 samples to assess the mortality risks associated with depression among men and women during 20 years of follow-up, and additionally among men with heavy smoking and alcoholism. Specific causes of death were investigated. RESULTS: hazard ratios representing the association between depression and premature death among men were 2.6 (95% CI 1.4 to 4.9) and 2.8 (95% CI 1.5 to 5.1), respectively, in the 1952 and 1970 samples for the first 10 years of follow-up. Hazard ratios for women were 1.4 (95% CI 0.6 to 3.2) and 1.2 (95% CI 0.5 to 2.9). The risk associated with depression among men was independent of alcoholism and heavy smoking. Depression and alcoholism were significantly associated with death by external causes and circulatory disease; heavy smoking was significantly associated with malignant neoplasms. CONCLUSION: the mortality associated with depression did not change during the period from 1952 to 1970. Depressed men experienced a significant mortality risk that was not matched among depressed women and also was not due to alcoholism and heavy smoking