Calculating WCET Estimates from Timed Traces

© The Author(s) 2015. This article is published with open access at Springerlink.comReal-time systems engineers face a daunting duty: They must ensure that each task in their system can always meet its deadline. To analyse schedulability they must know the worst-case execution time (WCET) of each task. However, determining exact WCETs is practically infeasible in cost-constrained industrial settings involving real-life code and COTS hardware. Static analysis tools that could yield sufficiently tight WCET bounds are often unavailable. As a result, interest in portable analysis approaches like measurement-based timing analysis (MBTA) is growing. We present an approach based on integer linear programming (ILP) for calculating a WCET estimate from a given database of timed execution traces. Unlike previous work, our method specifically aims at reducing overestimation, by means of an automatic classification of code executions into scenarios with differing worst-case behaviour. To ease the integration into existing analysis tool chains, our method is based on the implicit path enumeration technique (IPET). It can thus reuse flow facts from other analysis tools and produces ILP problems that can be solved by off-the-shelf solvers.Peer reviewe

Primary follicular and marginal-zone lymphoma of the breast: clinical features, prognostic factors and outcome: a study by the International Extranodal Lymphoma Study Group

Background: Primary breast lymphoma (PBL) of low-grade histology is a rare disease. This multicentric retrospective study was carried out to determine clinical features, prognosis and relapse. Patients and methods: Patients with histologically proven, previously untreated follicular or marginal-zone PBL (MZL PBL) diagnosed from 1980 to 2003 were included in the study. Major end points were progression-free survival (PFS), overall survival (OS) and potential prognostic factors. Results: We collected data on 60 cases of PBL [36 follicular and 24 marginal-zone lymphoma (MZL)]. Stage was IE or IIE in 57 patients and IVE in three patients due to bilateral breast involvement. Surgery, chemotherapy and radiotherapy (RT), alone or in combination, were used as first-line treatments in 67%, 42% and 52% of patients, respectively. Overall response rate was 98%, with a 93% complete response rate. Five-year PFS were 56% for MZL and 49% for follicular PBL (P = 0.62). Relapses were mostly in distant sites (18 of 23 cases); no patients relapsed within RT fields. Conclusions: Our data showed an indolent behaviour of MZL PBL, comparable to other primary extranodal MZL. Conversely, patients with follicular PBL had inferior PFS and OS when compared with limited-stage nodal follicular non-Hodgkin's lymphomas, suggesting an adverse prognostic role of primary breast localisation in this histological subgrou

Plasma Dynamics

Contains table of contents for Section 2 and reports on four research projects.Lawrence Livermore National Laboratory Subcontract 6264005National Science Foundation Grant ECS 84-13173National Science Foundation Grant ECS 85-14517U.S. Air Force - Office of Scientific Research Contract AFOSR 89-0082-AU.S. Army - Harry Diamond Laboratories Contract DAAL02-86-C-0050U.S. Navy - Office of Naval Research Contract N00014-87-K-2001Lawrence Livermore National Laboratory Subcontract B108472National Science Foundation Grant ECS 88-22475U.S. Department of Energy Contract DE-FG02-91-ER-54109National Aeronautics and Space Administration Grant NAGW-2048U.S. Department of Energy Contract DE-AC02-ET-51013U.S. Department of Energy Contract DE-AC02-78-ET-5101

Plasma Dynamics

Contains table of contents for Section 2 and reports on four research projects.Lawrence Livermore National Laboratory Subcontract 6264005National Science Foundation Grant ECS 84-13173National Science Foundation Grant ECS 85-14517U.S. Air Force - Office of Scientific Research Contract AFOSR 84-0026U.S. Army - Harry Diamond Laboratories Contract DAAL02-86-C-0050U.S. Navy - Office of Naval Research Contract N00014-87-K-2001National Science Foundation Grant ECS 85-15032National Science Foundation Grant ECS 88-22475U.S. Department of Energy Contract DE-AC02-ET-5101

Plasma Dynamics

Contains table of contents for Section 2 and reports on four research projects.National Science Foundation Grant ECS-89-02990U.S. Air Force - Office of Scientific Research Grant AFOSR 89-0082-CU.S. Army - Harry Diamond Laboratories Contract DAAL02-89-K-0084U.S. Army - Harry Diamond Laboratories Contract DAAL02-92-K-0037U.S. Department of Energy Contract DE-AC02-90ER-40591U.S. Navy - Office of Naval Research Grant N00014-90-J-4130Lawrence Livermore National Laboratories Subcontract B-160456National Aeronautics and Space Administration Grant NAGW-2048National Science Foundation Grant ECS-88-22475U.S. Department of Energy Grant DE-FG02-91-ER-5410

Plasma Dynamics

Contains table of contents for Section 2 and reports on four research projects.National Science Foundation Grant ECS 89-02990U.S. Air Force - Office of Scientific Research Grant AFOSR 89-0082-BU.S. Army - Harry Diamond Laboratories Contract DAAL02-89-K-0084U.S. Department of Energy Contract DE-AC02-90ER40591U.S. Navy - Office of Naval Research Grant N00014-90-J-4130Lawrence Livermore National Laboratory Subcontract B-160456National Science Foundation Grant ECS 88-22475U.S. Department of Energy Contract DE-FG02-91-ER-54109National Aeronautics and Space Administration Grant NAGW-2048U.S.-Israel Binational Science Foundation Grant 87-0057U.S Department of Energy Contract DE-AC02-78-ET-5101

Plasma Dynamics

Contains table of contents for Section 2 and reports on three research projects.National Science Foundation Grant ECS 89-02990U.S. Air Force - Office of Scientific Research Grant F49620-93-1-0108U.S. Army - Harry Diamond Laboratories Contract DAAL02-92-K-0037U.S. Department of Energy Grant DE-FG02-91-ER-40648U.S. Navy - Office of Naval Research Grant N00014-90-J-4130National Aeronautics and Space Administration Grant NAGW-2048National Science Foundation Grant ECS 88-22475U.S. Department of Energy Grant DE-FG02-91-ER-54109Magnetic Fusion Science Fellowship Progra