Предсказательное техническое обслуживание трубопроводов на основе экспресс-оценки степени опасности дефектов

The paper describes a tested and proven practical methodology of predictive maintenance of pipelines with two types of defects — “loss of metal” and “pipe wall lamination”, detected by the ILI technology. The laminations are caused by the steel and pipe manufacturing technology, and may also appear during pipeline operation. The laminations can be further classified as metallurgical laminations, hydrogen induced cracking (HIC), non-metallic inclusions, and such. For the defects of the “pipe wall lamination” type the assessment of their level of danger is conducted only after they are converted to surface “loss of metal” type defects. The paper presents models on how to adequately convert the “pipe wall lamination” type of defects to the “loss of metal” type defects. A methodology is described on how to rank the defects according to their level of danger (with respect to the rupture type of failure), and how to perform the probabilistic assessment of the pipeline residual life. In order to account for “leak” and “rupture” types of failure, a computer based express assessment is developed of the level of severity of each defect. This defect assessment is based on graphs, which restrict the permissible sizes of defects and allow making operative decisions as to which maintenance measures should be taken, regarding pipeline segment as a whole. The pipeline defects are ranked according to their potential danger, which depends on their location on the graphs. The probabilistic assessment of the residual pipeline life is performed taking into account the stochastic nature of defect growth. In order to achieve this, the maximal γ-percentile corrosion rate is defined over all detected defects. As the main decision parameter the gamma-percent operating time is chosen. It is characterized by: the safe operating time, and the percentile probability that during this time the pipeline limit state will not be reached. A detailed example of implementation of the described methodology to a real product pipeline segment operating in a severe corrosion environment is given. The economical effect of the implementation is outlined.Статья описывает проверенную практическую методологию предсказательного технического обслуживания (мейнтенанса) трубопроводов с двумя типами дефектов — «потеря металла» и «несплошность металла стенки трубы — расслоение», обнаруженных с помощью технологии внутритрубной диагностики (ВТД). Несплошности металла стенки трубы возникают в процессе сталеплавильного и прокатного производства, а также в процессе эксплуатации. К этим дефектам относятся: металлургические расслоения, водородные расслоения, закаты и плотные неметаллические включения. Для дефектов, относящихся к этому типу, оценка степени опасности производится только после приведения дефекта к поверхностному дефекту типа «потеря металла». В работе представлены модели приведения несплошности металла к поверхностным дефектам типа «потеря металла». Методика описывает способ ранжировки дефектов по уровню их опасности (относительно отказа типа «разрыв») и вероятностную оценку остаточного ресурса трубопровода. Для учета обоих сценариев отказа «течь» и «разрыв» строится компьютерная экспресс-оценка степени опасности дефектных участков трубопровода путем построения графиков, ограничивающих размеры дефектов трубопровода и позволяющих принимать оперативные решения о мерах по дальнейшей эксплуатации трубопровода. Осуществляется классификация потенциальной опасности дефектов трубопровода в зависимости от области их расположения на графиках. Расчет вероятностной оценки прогнозирования остаточного ресурса трубопровода проведен с учетом вероятностного подрастания дефектов. Для этого определяется максимальная, с заданной вероятностью γ, скорость коррозии по всем дефектам. В качестве основного показателя определяется гамма-процентный ресурс, задаваемый двумя численными значениями: наработкой и выраженной в процентах вероятностью того, что в течение этой наработки предельное состояние не будет достигнуто. Данная работа описывает пример применения описанной методологии к наземному участку трубопровода, транспортирующему сильнодействующий коррозионный конденсат. Также обсуждается экономический эффект от реализации представленной методологии

Macroeconomic Aspects of Maintenance Optimization of Critical Infrastructures

The main goal of maintenance is prevention, timely detection and elimination of failures and damage. From the point of view of critical infrastructures (CIs), the main purpose of their maintenance is to increase the safety of CIs and / or to ensure life safety. CIs should be optimal in terms of their purpose, cost, as a source of income and profit at all stages of their life cycle, and also acceptable in terms of possible loss of human lives or injuries. The paper considers the assessment of necessary optimal investments in the maintenance (time interval between subsequent maintenance), to increase the safety of life, the so-called life saving costs. The problem of limiting the threat to human life is as follows: “how much money is society ready and able to spend to reduce the likelihood of premature death”. A quantitative criterion of risk acceptance is used, in which the marginal cost of life saving is compared with social willingness to pay. This value is determined using the life quality index of population

Anomalous diffusion in the dynamics of complex processes

Anomalous diffusion, process in which the mean-squared displacement of system states is a non-linear function of time, is usually identified in real stochastic processes by comparing experimental and theoretical displacements at relatively small time intervals. This paper proposes an interpolation expression for the identification of anomalous diffusion in complex signals for the cases when the dynamics of the system under study reaches a steady state (large time intervals). This interpolation expression uses the chaotic difference moment (transient structural function) of the second order as an average characteristic of displacements. A general procedure for identifying anomalous diffusion and calculating its parameters in real stochastic signals, which includes the removal of the regular (low-frequency) components from the source signal and the fitting of the chaotic part of the experimental difference moment of the second order to the interpolation expression, is presented. The procedure was applied to the analysis of the dynamics of magnetoencephalograms, blinking fluorescence of quantum dots, and X-ray emission from accreting objects. For all three applications, the interpolation was able to adequately describe the chaotic part of the experimental difference moment, which implies that anomalous diffusion manifests itself in these natural signals. The results of this study make it possible to broaden the range of complex natural processes in which anomalous diffusion can be identified. The relation between the interpolation expression and a diffusion model, which is derived in the paper, allows one to simulate the chaotic processes in the open complex systems with anomalous diffusion.Comment: 47 pages, 15 figures; Submitted to Physical Review

Analysis of cross-correlations in electroencephalogram signals as an approach to proactive diagnosis of schizophrenia

We apply flicker-noise spectroscopy (FNS), a time series analysis method operating on structure functions and power spectrum estimates, to study the clinical electroencephalogram (EEG) signals recorded in children/adolescents (11 to 14 years of age) with diagnosed schizophrenia-spectrum symptoms at the National Center for Psychiatric Health (NCPH) of the Russian Academy of Medical Sciences. The EEG signals for these subjects were compared with the signals for a control sample of chronically depressed children/adolescents. The purpose of the study is to look for diagnostic signs of subjects' susceptibility to schizophrenia in the FNS parameters for specific electrodes and cross-correlations between the signals simultaneously measured at different points on the scalp. Our analysis of EEG signals from scalp-mounted electrodes at locations F3 and F4, which are symmetrically positioned in the left and right frontal areas of cerebral cortex, respectively, demonstrates an essential role of frequency-phase synchronization, a phenomenon representing specific correlations between the characteristic frequencies and phases of excitations in the brain. We introduce quantitative measures of frequency-phase synchronization and systematize the values of FNS parameters for the EEG data. The comparison of our results with the medical diagnoses for 84 subjects performed at NCPH makes it possible to group the EEG signals into 4 categories corresponding to different risk levels of subjects' susceptibility to schizophrenia. We suggest that the introduced quantitative characteristics and classification of cross-correlations may be used for the diagnosis of schizophrenia at the early stages of its development.Comment: 36 pages, 6 figures, 2 tables; to be published in "Physica A

Infranetics – a New Umbrella MABICS-Converging Technologies Science for Infrastructures Design, Resilience and Business Continuity Management

The paper describes recent advances in Infranetics (Infrastructures + Cybernetics) – the new umbrella science based on the MABICS-converging technology (Digital Stochastic Mechanics and Design, Artificial Intelligence, Biotechnology, Information Technology, Cognitive and Social Sciences) that emerged in 2016 [1]. Infranetics is being constructed as a multidiscipline science to facilitate design and implementation of advanced resilient smart infrastructures-components of artificial nature, congruent with the new type of human performance that is emerging supported by NBIC technologies. The knowledge base and methodology of infranetics, as well as means of harmonized governance of urban and regional infrastructures and unresolved priority issues of infranetics are briefly outlined. The paper describes how to use infranetics when solving real life problems related to urban and regional development, resilience, and governance. © 2022 American Institute of Physics Inc.. All rights reserved

Black-Swan Type Catastrophes and Antifragility/Supra-resilience of Urban Socio-Technical Infrastructures

This paper may be one of the first attempts dealing with the problem of creating, providing and maintaining antifragility of systems of interdependent urban critical infrastructures (CI) in the wake of black-swan type technological, ecological, economic or social catastrophes occurring in a municipality. A synonym is offered to describe antifragility from a positive psychology perspective, formulating the problem as the supraresilience problem. A brief description is given of the developed innovative approach for creating a supraresilient city/region using black-swan catastrophe and the antifragility concepts. Resilience metrics are formulated as well as methods of assessing damage, interdependence of infrastructures and convergent technologies and sciences needed for practical regional resilience and risk management of the system of systems (SoS) of interdependent urban critical infrastructures). © Published under licence by IOP Publishing Ltd