@inproceedings{SykoraMarkovaDiamantidis, author = {S{\´y}kora, Miroslav and Markova, Jana and Diamantidis, Dimitris}, title = {Bayesian Network Application for the Risk Assessment of Existing Energy Production Units}, series = {2016 Second International Symposium on Stochastic Models in Reliability Engineering, Life Science and Operations Management (SMRLO), 15-18 Feb. 2016, Beer Sheva, Israel}, booktitle = {2016 Second International Symposium on Stochastic Models in Reliability Engineering, Life Science and Operations Management (SMRLO), 15-18 Feb. 2016, Beer Sheva, Israel}, publisher = {IEEE}, doi = {10.1109/SMRLO.2016.116}, pages = {656 -- 664}, abstract = {A Bayesian network is applied in this contribution in order to assess the risks of a selected production unit in a fossil power station. A general framework for the risk assessment of production units of a power station is presented first by implementing statistical methods and Bayesian networks. Special emphasis is given to the input data consisting of failure rates which are obtained on the basis of recorded data and expert judgements. The consequences of failure are divided into economical and human (societal): economic consequences include outages of key technological devices, societal consequences cover potential injuries and fatalities. Probabilistic risk assessment methods are applied to the selected production unit of a power station. The influence of the uncertainties in the considered technical parameters on the availability of the unit is assessed and the acceptance of the calculated availability represented through the mean value and the standard deviation is discussed. Societal risks given in terms of weighted injuries and fatalities are obtained and respective risk acceptance criteria are presented. Uncertainties affecting the risks are discussed. It appears that the proposed framework provides a valuable assessment of the influence individual devices and their components on availability and societal risk. For that purpose the used methodology, intentionally simplified for operational applications, includes important factors affecting risks of production units. It is concluded that Bayesian networks are a transparent method for the probabilistic risk assessment of complex technological systems. The results of the performed analyses can be easily updated when additional information becomes available as illustrated in characteristic examples.}, language = {en} } @inproceedings{SykoraDiamantidisHolickyetal., author = {S{\´y}kora, Miroslav and Diamantidis, Dimitris and Holick{\´y}, Milan and Markova, Jana and Charters Morais, Eduardo}, title = {Compressive Strength of Historic Masonry based on Destructive and Non-Destructive Test Results}, series = {Proceedings of the 3rd International Conference on Protection of Historical Constructions (PROHITECH'17), July 12-15, 2017, Lisbon, Portugal}, booktitle = {Proceedings of the 3rd International Conference on Protection of Historical Constructions (PROHITECH'17), July 12-15, 2017, Lisbon, Portugal}, language = {en} } @article{SykoraMarkovaDiamantidis, author = {S{\´y}kora, Miroslav and Markova, Jana and Diamantidis, Dimitris}, title = {Bayesian network application for the risk assessment of existing energy production units}, series = {Reliability Engineering \& System Safety}, volume = {169}, journal = {Reliability Engineering \& System Safety}, number = {January}, publisher = {Elsevier}, doi = {10.1016/j.ress.2017.09.006}, pages = {312 -- 320}, abstract = {The assessment of existing infrastructures in the energy sector is of great economic significance worldwide. Fossil power stations are reaching their design service life and rational decisions concerning extensions of service life, maintenance and replacements of devices should be based on updated information of the actual conditions of the energy devices and their components, and on cost-benefit analysis using risk analysis and probabilistic optimisation procedures. The contribution provides an integrated framework for probabilistic reliability and risk assessment of existing energy production units considering availability and human safety criteria. An extensive case study focused on risks of an energy production unit in a fossil power station is provided to support practical applications. A Bayesian network is thereby implemented to assess the risks of the selected production unit. Special emphasis is given to the input data consisting of failure rates obtained from recorded data and expert judgements. The influence of uncertainties in the considered performance indicators on the availability of the unit is analysed. It is shown that a reasonably simplified framework can provide a valuable assessment of the influence of individual devices and their components on availability and societal risk, identifying thus the major risk contributors. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{SykoraDiamantidisHolickyetal., author = {S{\´y}kora, Miroslav and Diamantidis, Dimitris and Holick{\´y}, Milan and Markov{\´a}, Jana and R{\´o}zs{\´a}s, {\´A}rp{\´a}d}, title = {Assessment of compressive strength of historic masonry using non-destructive and destructive techniques}, series = {Construction and Building Materials}, volume = {193}, journal = {Construction and Building Materials}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.conbuildmat.2018.10.180}, pages = {196 -- 210}, abstract = {Masonry structures were built by various techniques using different materials, the properties of which exhibit a considerable scatter dependent on periods of construction and region-specific conditions. For historic structures with a heritage value, various non- or minor-destructive tests (NDTs) are commonly applied, while the application of destructive tests (DTs) is minimized. The contribution is based on investigations of 15 historic stone and clay brick masonry structures, for which NDT strengths of masonry units are verified by DTs. The proposed operational approach makes it possible to account for statistical uncertainty due to a limited number of DTs used to calibrate NDTs.}, language = {en} } @book{HolickyDiamantidisSykoraetal., author = {Holick{\´y}, Milan and Diamantidis, Dimitris and S{\´y}kora, Miroslav and Markov{\´a}, Jana and Vrouwenfelder, Ton and Tanner, Peter and Arteaga, Angel and Lara Sarache, Carlos and Croce, Pietro and Toprak, Selcuk and Senel, Sevket Murat and Inel, Mehmet}, title = {Methods for the risk assessment and risk-based management of aging infrastructure}, publisher = {Czech Technical University in Prague, Klokner Institute}, address = {Prague}, isbn = {978-80-01-05611-0}, abstract = {The Leonardo da Vinci Project, "Innovation Transfer in Risk Assessment and Management of Aging Infrastructures", CZ/13/LLP-LdV/TOI/134014, addresses the urgent need to train students, young engineers and professionals in the assessment of existing infrastructures. The future of the construction industry lies in moving from new constructions towards the maintenance, repair and rehabilitation of existing structures, particularly of aging infrastructures. Risk management consisting of risk assessment and risk control of existing structure therefore plays thereby an important role. The assessment of existing infrastructures is an imperative issue of great economic significance in most countries around the world, as more than 50 \% of all construction activities concerns existing buildings, bridges and other civil engineering works. At present, the Eurocodes which will be used in all CEN Member countries are primarily focused on the design of new structures. Additional operational rules for existing structures are still missing. The international standard ISO 13822 provides only general principles for the assessment of existing structures which should be further developed for their effective operational use in practice. The overall procedure of risk management of aging infrastructures is therefore an urgent issue of great economic significance in most countries around the world. This is primarily caused due to the fact that many infrastructures are affected by action effects, fatigue and environmental influences, and inevitably deteriorate. Moreover, available resources for the maintenance, repair or possible replacement of infrastructures are always limited. Typical questions and problems which must be solved in this context can be summarized as follows: • What is the current state of a particular infrastructure? • What is an acceptable level of the relevant risk? • Which aspects are critical to sustainable performance? • What is the optimum life-cycle cost? • What is the best long-term funding strategy? The proposed project highlights the above problems and focusses also on vocational training in risk management and assessment of aging infrastructure in the partner countries (CZ, DE, ES, IT and TR). The current project addresses the urgent need for practical implementation of principles of the management and risk assessment of existing infrastructures in all the partner countries. The project is supported by the Czech Chamber of Chartered Engineers (ČKAIT). The project consortium, under the leadership of the Klokner Institute of the Czech Technical University in Prague (KI CTU), consists of five other partners, including research institutions and universities from three EU Member States (DE, ES, IT) as well as one associated country (TR), and also the Secondary Technical School of Civil Engineering in Ceske Budejovice (CZ). All researchers within the partnership are involved in research projects dealing with reliability assessment of existing structures. They participate in the national and international standardization activities within the international organizations CEN (European Committee for Standardisation) and ISO (International Standardization Organisation). The project outcomes consist of vocational training materials based on international research and relevant standard committee's activities, and on the significant experience gained from case studies, and on selected results obtained from the previous projects of the Leonardo da Vinci programme. In particular, the experience gained by the partners of the present consortium from the completed project on vocational training related to assessment of existing structures is utilized. Available innovations are transferred to undergraduate and graduate students, practising engineers and local government representatives. The developed training materials are of practical use in offering illustrative examples and several case studies. All the project outcomes are based on documents of the international research organization, Joint Committee on Structural Safety JCSS and international research projects, selected outcomes of the previous project of the Leonardo da Vinci programme (developed by five partners of the present consortium in 2013-2015) and also on background documents to the new European and international standards. Particular outcomes of the proposed project include practical handbooks, software tools, web-sites, e-learning, courses and seminars organized in the partners´ home countries. The project outcomes will also be offered to other European countries through code committees work, lectures and the project web-sites. It is foreseen that the outcomes being used by engineers, designers, technicians, and representatives of public authorities involved in planning and management will have an impact on the risk-based management of infrastructures. One of the important project outcomes is the present Handbook 1 "Methods for the Risk Assessment and Risk-Based Management of Aging Infrastructure", which is focussed on general procedures of risk-management and assessment of aging infrastructures. The methodologies provided are independent of the type of structure and material, and are compatible with the background methodologies used in the Eurocodes. Operational techniques for the assessment of aging infrastructures supplemented by illustrative case studies are presented in Handbook 2 and Handbook 3, which also result from the mentioned project. Handbook 1 consists of ten chapters and one annex. Chapter 1 gives a brief overview of the basic concepts used in the management and risk assessment of existing structures, supplemented by the basic definitions and terminology. Chapter 2 summarizes current applicable standards, codes and recommendations related to actions and environmental influences on existing structures. Chapter 3 reviews the most important degradation models due to environmental influences. Fatigue effects are treated separately in Chapter 4. The following Chapters, 5, 6, 7 and 8, are devoted step by step to the entire procedure of risk management, including probabilistic reliability analysis, consequence analysis, risk evaluation and risk assessment based on risk acceptance criteria, and consequently provide important information supporting decisions concerning the safety of the structure. The last two Chapters, 9 and 10, illustrate instructive case studies concerning risk management and risk assessment of road tunnels. Annex A presents basic statistical methods and techniques used in the evaluation and updating of available data required for probability and consequence analysis. It is believed that the material of this handbook is presented in an understandable way, illustrated by several realistic examples. A number of references mentioned in each chapter provide additional background materials, further guidance and information useful for particular practical applications. Prague and Regensburg, 2014}, language = {en} }