parMERASA Multi-Core Execution of Parallelised Hard Real-Time Applications Supporting Analysability

International audienceEngineers who design hard real-time embedded systems express a need for several times the performance available today while keeping safety as major criterion. A breakthrough in performance is expected by parallelizing hard real-time applications and running them on an embedded multi-core processor, which enables combining the requirements for high-performance with timing-predictable execution. parMERASA will provide a timing analyzable system of parallel hard real-time applications running on a scalable multicore processor. parMERASA goes one step beyond mixed criticality demands: It targets future complex control algorithms by parallelizing hard real-time programs to run on predictable multi-/many-core processors. We aim to achieve a breakthrough in techniques for parallelization of industrial hard real-time programs, provide hard real-time support in system software, WCET analysis and verification tools for multi-cores, and techniques for predictable multi-core designs with up to 64 cores

The influence of gender on patency rates after iliac artery stenting

ObjectiveThe purpose of this study was to investigate the influence of gender on the long-term outcome after iliac artery stenting and to assess gender-specific differences of the influence of risk factors on treatment success and patency rates.MethodsBetween January 2000 and December 2006, 404 percutaneous transluminal angioplasties with primary stent deployment for symptomatic iliac artery occlusive disease were performed at our center. These included 128 interventions in women and 276 interventions in men.ResultsWhereas average age was significantly higher (65.9 ± 12.9 years; P = .007) and arterial hypertension more frequent (60.9% vs 49.3%; P = .032) in women, hyperuricemia (7.0% vs 14.1%; P = .047) and a positive smoking status (61.7% vs 74.3%; P = .014) were more frequently observed in men. Fontaine stage was more advanced (stages III and IV) in women than in men (P = .028; P < .001). Technical success was 97.7% in women and 99.3% in men. Overall complication rate was higher in women compared with men (P = .002), mostly caused by access site hematomas (4.7% vs 0.4%) and pseudoaneurysms (8.6% vs 2.5%). Patients were followed up for 45.0 ± 33.3 months. Restenosis developed in 16.8% of cases in women and in 14.6% of cases in men and was treated in 73.7% by an endovascular approach. Primary patency rates at 1, 3, 5, and 7 years were 90.3%, 77.2%, 60.2%, and 46.4% in women and 89.9%, 71.5%, 63.6%, and 59.7% in men, respectively (P = .524; log-rank, .406). Secondary patency rates were 97.2%, 91%, 81.5%, and 70.3% in women and 97.1%, 89.1%, 82.6%, and 78% in men, respectively (P = .959; log-rank, .003). Multivariate analysis identified lower age as the only independent risk factor for recurrent disease in both groups. Age-defined subgroup analysis showed a restenosis/reocclusion rate of 23.9% in men and 22.1% in women older than 63.5 years (P = .861) but 32.1% in men and 49.1% in women younger than that (P = .034).ConclusionsOur data suggest that although women are older and present with a more advanced stage of peripheral arterial occlusive disease, endovascular therapy is equally effective irrespective of gender. Surprisingly, the subgroup of young female patients had a specifically poor outcome

The influence of gender on patency rates after iliac artery stenting

ObjectiveThe purpose of this study was to investigate the influence of gender on the long-term outcome after iliac artery stenting and to assess gender-specific differences of the influence of risk factors on treatment success and patency rates.MethodsBetween January 2000 and December 2006, 404 percutaneous transluminal angioplasties with primary stent deployment for symptomatic iliac artery occlusive disease were performed at our center. These included 128 interventions in women and 276 interventions in men.ResultsWhereas average age was significantly higher (65.9 ± 12.9 years; P = .007) and arterial hypertension more frequent (60.9% vs 49.3%; P = .032) in women, hyperuricemia (7.0% vs 14.1%; P = .047) and a positive smoking status (61.7% vs 74.3%; P = .014) were more frequently observed in men. Fontaine stage was more advanced (stages III and IV) in women than in men (P = .028; P < .001). Technical success was 97.7% in women and 99.3% in men. Overall complication rate was higher in women compared with men (P = .002), mostly caused by access site hematomas (4.7% vs 0.4%) and pseudoaneurysms (8.6% vs 2.5%). Patients were followed up for 45.0 ± 33.3 months. Restenosis developed in 16.8% of cases in women and in 14.6% of cases in men and was treated in 73.7% by an endovascular approach. Primary patency rates at 1, 3, 5, and 7 years were 90.3%, 77.2%, 60.2%, and 46.4% in women and 89.9%, 71.5%, 63.6%, and 59.7% in men, respectively (P = .524; log-rank, .406). Secondary patency rates were 97.2%, 91%, 81.5%, and 70.3% in women and 97.1%, 89.1%, 82.6%, and 78% in men, respectively (P = .959; log-rank, .003). Multivariate analysis identified lower age as the only independent risk factor for recurrent disease in both groups. Age-defined subgroup analysis showed a restenosis/reocclusion rate of 23.9% in men and 22.1% in women older than 63.5 years (P = .861) but 32.1% in men and 49.1% in women younger than that (P = .034).ConclusionsOur data suggest that although women are older and present with a more advanced stage of peripheral arterial occlusive disease, endovascular therapy is equally effective irrespective of gender. Surprisingly, the subgroup of young female patients had a specifically poor outcome

Evaluation of volumetric measurements in patients with acute type B aortic dissection – thoracic endovascular aortic repair (TEVAR) vs conservative

ObjectiveThe aim of this retrospective study was to evaluate aortic volume changes in patients with acute type B aortic dissection (TBD), treated either by thoracic endovascular aortic repair (TEVAR) or conservatively.Materials and MethodsFrom July 1996 through March 2008, 76 patients presenting with acute TBD were referred to our department. To ensure a follow-up of at least 24 months, only 64 of them were included in the present study, with the cut-off for inclusion being March 2006. Twenty-nine of these patients underwent TEVAR and 35 patients underwent conservative treatment. Indications for TEVAR were life-threatening symptoms. Follow-up was performed postinterventionally in patients after TEVAR and at 3, 6, and 12 months, and yearly thereafter in both groups. It included clinical examinations, computed tomography (CT) scans, analysis of volume changes in true thoracic lumen (TTL), false thoracic lumen (FTL), thoracic lumen (TL), abdominal lumen (AL), and aortic diameter measurements. In addition, the extent of thrombosis and its influence on volume changes were assessed.ResultsMean follow-up was 41 months after TEVAR and 46 months in the conservatively-treated patients. At 60 months, cumulative rates of freedom from dissection-related death and rupture-free survival were 82.6% and 93.1% in the TEVAR group, respectively. They were 74.9% and 88.5% in the conservatively-treated group, respectively. In the conservatively-treated patients, 3 patients died of late aortic rupture, 4 were converted to open surgery, and 2 to TEVAR. Evaluation of volume changes showed better results in the TEVAR group within 24 months. However, within 60 months the difference between the two groups was no longer relevant. Relating to thrombosis of the FTL, analyses showed slightly better overall results and promotion of thrombus formation after TEVAR. However, at 60 months the results showed a tendency towards approximation between the two groups.ConclusionOur data suggest that TEVAR seems to delay the natural course of the disease but not to stop it

A Parallelization Approach for Hard Real-Time Systems and Its Application on Two Industrial Programs

International audienceApplications in industry often have grown and improved over many years. Since their performance demands increase, they also need to benefit from the availability of multi-core processors. However, a reimplementation from scratch and even a restructuring of these industrial applications is very expensive, often due to high certification efforts. Therefore, a strategy for a systematic parallelization of legacy code is needed. We present a parallelization approach for hard real-time systems, which ensures a high reusage of legacy code and preserves timing analysability. To show its applicability, we apply it on the core algorithm of an avionics application as well as on the control program of a large construction machine. We create models of the legacy programs showing the potential of parallelism, optimize them and change the source codes accordingly. The parallelized applications are placed on a predictable multi-core processor with up to 18 cores. For evaluation, we compare the worst case execution times and their speedups. Furthermore, we analyse limitations coming up at the parallelization process