TY - CHAP A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris T1 - Snow Load Monitoring - Measure to Control Reliability of the Roof of a Stadium T2 - International Conference Structural Reliability & Modelling in Mechanics, 24.-25.05.2018, Ostrava, Czech Republic N2 - This contribution shows how monitoring can be used to control reliability of a structure not complying with the requirements of Eurocodes. A general methodology to obtain cost-optimal decisions using limit state design, probabilistic reliability analysis and cost estimates is utilised in a full-scale case study dealing with the roof of a stadium located in Northern Italy. The results demonstrate the potential of monitoring systems and probabilistic reliability analysis to support decisions regarding safety measures such as snow removal, or temporary closure of the stadium. KW - Cost optimisation KW - decision making criteria KW - Eurocodes KW - monitoring KW - reliability analysis KW - snow load KW - stadium roof KW - standard Y1 - 2018 UR - www.researchgate.net/publication/325569518_Snow_Load_Monitoring_-_Measure_to_Control_Reliability_of_the_Roof_of_a_Stadium ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Optimizing Monitoring - Implementation of Draft Guideline and Case Study of Roof Exposed to Snow Loads T2 - Proceedings of 40th IABSE Symposium : Tomorrow's Megastructures, Nantes, France, 19-21 September 2018 N2 - This contribution addresses the optimisation of monitoring and decision-making criteria regarding the future use of structures and the related implementation in modern guidelines. A summary of the state-of-practice reveals deficiencies that are addressed by prospective guidance for the anticipated updates of standards, providing a general methodology to obtain cost-optimal decisions using limit state design, probabilistic reliability analysis and cost estimates. The implementation of a draft guideline and the corresponding risk-based approach are illustrated in a full-scale case study dealing with the roof of a stadium located in Northern Italy. The results demonstrate the potential of using monitoring systems and probabilistic reliability analysis in order to support decisions regarding safety measures such as snow removal, or temporary closure of the stadium. KW - cost optimisation KW - decision making criteria KW - Eurocodes KW - monitoring KW - reliability analysis KW - snow load KW - stadium roof KW - standard Y1 - 2018 SN - 978-3-85748-161-1 U6 - https://doi.org/10.2749/nantes.2018.s27-27 PB - Curran Associates Inc CY - Red Hook, NY ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Lenzi, Daniele A1 - Sýkora, Miroslav T1 - Optimal decisions based on monitoring – case study of steel roof T2 - Proceedings of the Joint COST TU1402-TU1406 - IABSE WC1 Workshop, Zagreb 2-3 March 2017 N2 - Monitoring of structures and related decisions based on cost optimization are discussed in this contribution. Many research publications and experimental data are currently available on inspection and on monitoring and they represent the outcome of the remarkable work done. Not all the topics of interest are widely debated and implemented in standards. The current state-of-practice in standards is summarized and aspects to be included in future recommendations are proposed. The implementation of risk-based decisions is illustrated in a case study dealing with a stadium roof in Northern Italy. Snow actions are important especially in northern and mountainous regions where heavy snowfalls and related accumulation result to considerable loads. As the roof structure fails to comply with the requirements of Eurocodes, a permanent monitoring system has been installed to allow for real time evaluation of the reliability level of the structure. The system supplies the necessary information supporting immediate decisions on closure of the stadium in case of an extraordinary snow load. Cost-optimal decisions regarding the closure of the stadium are analysed based on a limit state function, on probabilistic models for the influencing parameters including measurement uncertainty, economic losses related to closure and failure consequences. The results demonstrate the potential of the use of the monitoring systems and probabilistic reliability analysis in order to support decisions and highlight the need for their implementation in future standards. KW - probabilistic methods KW - reliability analysis KW - reliability level KW - risk analysis KW - SHM KW - snow load KW - monitoring Y1 - 2017 U6 - https://doi.org/10.5592/CO/BSHM2017.4.7 SP - 4.7-1 EP - 4.7-7 ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Implementing Snow Load Monitoring to control Reliability of a Stadium Roof T2 - Transactions of VSB N2 - This contribution shows how monitoring can be used to control reliability of a structure not complying with the requirements of Eurocodes. A general methodology to obtain cost-optimal decisions using limit state design, probabilistic reliability analysis and cost estimates is utilised in a full-scale case study dealing with the roof of a stadium located in Northern Italy. The results demonstrate the potential of monitoring systems and probabilistic reliability analysis to support decisions regarding safety measures such as snow removal, or temporary closure of the stadium. KW - Cost optimisation KW - decision making criteria KW - Eurocodes KW - monitoring KW - reliability analysis KW - snow load KW - stadium roof, standard Y1 - 2019 U6 - https://doi.org/10.35181/tces-2019-0006 VL - 19 IS - 1 SP - 35 EP - 40 PB - TECHNICAL UNIVERSITY OF OSTRAVA ER - TY - CHAP A1 - Raab, Peter A1 - Racek, Stanislav A1 - Krämer, Stefan A1 - Mottok, Jürgen T1 - Reliability of Task Execution during Safe Software Processing T2 - 15th Euromicro Conference on Digital System Design, Cesme, Turkey N2 - This paper presents the reliability evaluation of task execution during safe software processing. The standard method of duplication in a safety-critical application can also be applied for tasks in a software system. But in addition to this, there is also the possibility for coded task processing to increase the reliability and availability of software. The presented analysis covers the reliability analysis of a single, a duplicated and a coded task by the technique of continuous time Markov processes. Markov processes are often used for the reliability evaluation of safety-critical systems. We introduce a method to describe the execution time of tasks by means of enhanced Markov models and their solution by numerical methods. KW - reliability analysis KW - continuous-time Markov process KW - error probability KW - Erlang-distribution Y1 - 2012 U6 - https://doi.org/10.1109/DSD.2012.110 SP - 84 EP - 89 ER - TY - CHAP A1 - Krämer, Stefan A1 - Raab, Peter A1 - Mottok, Jürgen A1 - Racek, Stanislav T1 - Comparison of Enhanced Markov Models and Discrete Event Simulation – for evaluation of probabilistic Faults in safety-critical real-time task sets T2 - Proceedings of EUROMICRO DSD 2014 - 17th Euromicro Conference on Digital System Design N2 - In this paper we present simulation and model based approaches for evaluating and validating the temporal and safety relevant properties of software intensive safety-critical real-time embedded systems. A high level reliability model of a safe task execution is described by a continuous-time Markov process, enhanced by the modeling of execution times. It is shown that the behavior - regarding real-time and safety metrics - of this theoretical model can be transferred into an abstract system timing model, which then can be analyzed by a discrete event simulation approach. The verification of the discrete event simulation by Markov models offers the possibility of a holistic approach for reliability analysis combined with schedulability analysis of complex safety-critical multicore real-time systems by the discrete event simulation. KW - Model KW - Stochastic simulation KW - reliability analysis KW - safe software processing KW - real-time operating system KW - multicore scheduling KW - discrete event simulation KW - fault injection Y1 - 2014 U6 - https://doi.org/10.1109/DSD.2014.42 SP - 591 EP - 598 ER - TY - CHAP A1 - Raab, Peter A1 - Racek, Stanislav A1 - Krämer, Stefan A1 - Mottok, Jürgen T1 - Data Flow Analysis of Software Executed by Unreliable Hardware T2 - 16th Euromicro Conference on Digital System Design, Los Alamitos, CA, USA N2 - The data flow is a crucial part of software execution in recent applications. It depends on the concrete implementation of the realized algorithm and it influences the correctness of a result in case of hardware faults during the calculation. In logical circuits, like arithmetic operations in a processor system, arbitrary faults become a more tremendous aspect in future. With modern manufacturing processes, the probability of such faults will increase and the result of a software's data flow will be more vulnerable. This paper shows a principle evaluation method for the reliability of a software's data flow with arbitrary soft errors also with the concept of fault compensation. This evaluation is discussed by means of a simple example based on an addition. KW - data flow KW - error probability KW - fault compensation KW - reliability analysis KW - software-implemented-hardwarefault-tolerance (SIHFT) Y1 - 2013 U6 - https://doi.org/10.1109/DSD.2013.35 SP - 243 EP - 249 ER -