129,004 research outputs found

    Industrial implementation of intelligent system techniques for nuclear power plant condition monitoring

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    As the nuclear power plants within the UK age, there is an increased requirement for condition monitoring to ensure that the plants are still be able to operate safely. This paper describes the novel application of Intelligent Systems (IS) techniques to provide decision support to the condition monitoring of Nuclear Power Plant (NPP) reactor cores within the UK. The resulting system, BETA (British Energy Trace Analysis) is deployed within the UK’s nuclear operator and provides automated decision support for the analysis of refuelling data, a lead indicator of the health of AGR (Advanced Gas-cooled Reactor) nuclear power plant cores. The key contribution of this work is the improvement of existing manual, labour-intensive analysis through the application of IS techniques to provide decision support to NPP reactor core condition monitoring. This enables an existing source of condition monitoring data to be analysed in a rapid and repeatable manner, providing additional information relating to core health on a more regular basis than routine inspection data allows. The application of IS techniques addresses two issues with the existing manual interpretation of the data, namely the limited availability of expertise and the variability of assessment between different experts. Decision support is provided by four applications of intelligent systems techniques. Two instances of a rule-based expert system are deployed, the first to automatically identify key features within the refuelling data and the second to classify specific types of anomaly. Clustering techniques are applied to support the definition of benchmark behaviour, which is used to detect the presence of anomalies within the refuelling data. Finally data mining techniques are used to track the evolution of the normal benchmark behaviour over time. This results in a system that not only provides support for analysing new refuelling events but also provides the platform to allow future events to be analysed. The BETA system has been deployed within the nuclear operator in the UK and is used at both the engineering offices and on station to support the analysis of refuelling events from two AGR stations, with a view to expanding it to the rest of the fleet in the near future

    A review of applied methods in Europe for flood-frequency analysis in a changing environment

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    The report presents a review of methods used in Europe for trend analysis, climate change projections and non-stationary analysis of extreme precipitation and flood frequency. In addition, main findings of the analyses are presented, including a comparison of trend analysis results and climate change projections. Existing guidelines in Europe on design flood and design rainfall estimation that incorporate climate change are reviewed. The report concludes with a discussion of research needs on non-stationary frequency analysis for considering the effects of climate change and inclusion in design guidelines. Trend analyses are reported for 21 countries in Europe with results for extreme precipitation, extreme streamflow or both. A large number of national and regional trend studies have been carried out. Most studies are based on statistical methods applied to individual time series of extreme precipitation or extreme streamflow using the non-parametric Mann-Kendall trend test or regression analysis. Some studies have been reported that use field significance or regional consistency tests to analyse trends over larger areas. Some of the studies also include analysis of trend attribution. The studies reviewed indicate that there is some evidence of a general increase in extreme precipitation, whereas there are no clear indications of significant increasing trends at regional or national level of extreme streamflow. For some smaller regions increases in extreme streamflow are reported. Several studies from regions dominated by snowmelt-induced peak flows report decreases in extreme streamflow and earlier spring snowmelt peak flows. Climate change projections have been reported for 14 countries in Europe with results for extreme precipitation, extreme streamflow or both. The review shows various approaches for producing climate projections of extreme precipitation and flood frequency based on alternative climate forcing scenarios, climate projections from available global and regional climate models, methods for statistical downscaling and bias correction, and alternative hydrological models. A large number of the reported studies are based on an ensemble modelling approach that use several climate forcing scenarios and climate model projections in order to address the uncertainty on the projections of extreme precipitation and flood frequency. Some studies also include alternative statistical downscaling and bias correction methods and hydrological modelling approaches. Most studies reviewed indicate an increase in extreme precipitation under a future climate, which is consistent with the observed trend of extreme precipitation. Hydrological projections of peak flows and flood frequency show both positive and negative changes. Large increases in peak flows are reported for some catchments with rainfall-dominated peak flows, whereas a general decrease in flood magnitude and earlier spring floods are reported for catchments with snowmelt-dominated peak flows. The latter is consistent with the observed trends. The review of existing guidelines in Europe on design floods and design rainfalls shows that only few countries explicitly address climate change. These design guidelines are based on climate change adjustment factors to be applied to current design estimates and may depend on design return period and projection horizon. The review indicates a gap between the need for considering climate change impacts in design and actual published guidelines that incorporate climate change in extreme precipitation and flood frequency. Most of the studies reported are based on frequency analysis assuming stationary conditions in a certain time window (typically 30 years) representing current and future climate. There is a need for developing more consistent non-stationary frequency analysis methods that can account for the transient nature of a changing climate

    Data mining reactor fuel grab load trace data to support nuclear core condition monitoring

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    A critical component of an advanced-gas cooled reactor (AGR) station is the graphite core. As a station ages, the graphite bricks that comprise the core can distort and may eventually crack. As the core cannot be replaced the core integrity ultimately determines the station life. Monitoring these distortions is usually restricted to the routine outages, which occur every few years, as this is the only time that the reactor core can be accessed by external sensing equipment. However, during weekly refueling activities measurements are taken from the core for protection and control purposes. It is shown in this paper that these measurements may be interpreted for condition monitoring purposes, thus potentially providing information relating to core condition on a more frequent basis. This paper describes the data-mining approach adopted to analyze this data and also describes a software system designed and implemented to support this process. The use of this software to develop a model of expected behavior based on historical data, which may highlight events containing unusual features possibly indicative of brick cracking, is also described. Finally, the implementation of this newly acquired understanding in an automated analysis system is described

    Deep Space Network information system architecture study

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    The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control

    Geodetic and seismological observations applied for investigation of subsidence formation in the CSM Mine (Czech Republic)

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    Purpose. Undermined areas are affected by the creation of subsidence depressions due to long-term underground mining. In general, different geodetic methods are applied to obtain further information needed to determine the spatial development of the formation of a subsidence depression. Methods. Application of these surveying methods enables us to investigate spatio-temporal changes of landscape relief in detail. Although the development of surveying technologies is in progress at present, conventional geodetic methods are still in use. Nowadays Global Navigation Satellite System (GNSS) surveying is mostly used for obtaining the actual degree of relief affection in undermined areas. Considering that during coal extraction induced seismic events are observed underground and on the surface, some seismological methods for their parameters determination were applied, e.g. foci location of induced seismic events, their classification by units of magnitude and by released seismic energy, frequency energy distribution, construction of Benioff graph and its derivation for assessment of adjacent working endangerment. Findings. The results of the assessment and analyses of spatial data demonstrate the real development of the sub-sidence depression under study and the relief changes of the landscape during the investigated period, respectively. Originality. It was recognized that all methods applied in this study represent very helpful tools for surveying subsidence depression and simultaneous monitoring of seismic activity development on an undermined area. Practical implications. Based on obtained results it is possible to perform a comparison of current subsidence dimensions with the original rate of affection.Мета. Дослідження причин утворення просідань земної поверхні в околиці шахти CSM (Чеська Республіка) за допомогою геодезичних і сейсмологічних методів спостереження. Методика. В роботі використано сейсмічні методи для визначення локалізації місць явищ техногенної сейсмічності, їх класифікації за магнітудами і кількістю виділеної сейсмічної енергії та її частотного розподілу; побудову графіка Беньофа та його модифікацію для оцінки безпеки суміжних до шахти територій; моделювання просторово-часового розвитку опускання поверхні за допомогою GPS-вимірювань. Результати. У результаті оцінки та аналізу просторових даних була визначена реальна область просідань і зміни навколишнього рельєфу протягом всього часу проведення досліджень. Ґрунтуючись на аналізі наявних сейсмічних даних та наземних GPS-вимірювань, встановлено, що протягом досліджуваного періоду ніякого виразного впливу розвитку зсувів і деформацій поверхні через сейсмічну активність не спостерігалося. Виконано моделювання просторово-часового розвитку опускання поверхні у досліджуваній області, що дозволило визначити швидкість осідання поверхні з часом. Визначено горизонтальні переміщення окремих точок і встановлено, що великі тектонічні розломи створюють природний бар’єр зсувам у масиві. Наукова новизна. Використання унікального комплексу методів дослідження та моніторингу, застосовані у даній роботі, дозволили точно виявити область просідання поверхні й причини її утворення, а також здійснити моніторинг сейсмічної активності в районі, порушеному гірничими роботами. Практична значимість. Отримані результати дозволяють порівняти сучасний стан утворених просідань з їх початковими параметрами, а також прогнозувати інтенсивність їх розвитку у часі.Цель. Исследование причин образования проседания земной поверхности в окрестности шахты CSM (Чешская Республика) при помощи геодезических и сейсмологических методов наблюдения. Методика. В работе использовано сейсмические методы для определения локализации очагов явлений техногенной сейсмичности, их классификации по магнитудам и количеству выделенной сейсмической энергии и ее частотного распределения; построение графика Беньофа и его модификацию для оценки безопасности прилегающих к шахте территорий; моделирование пространственно-временного развития опускания поверхности при помощи GPS-измерений. Результаты. В результате оценки и анализа пространственных данных была определена реальная область проседаний и изменения окружающего рельефа в течение всего времени проведения исследований. Основываясь на анализе имеющихся сейсмических данных и наземных GPS-измерений, установлено, что в течение исследуемого периода никакого выразительного влияния развития смещений и деформаций поверхности из-за сейсмической активности не наблюдалось. Выполнено моделирование пространственно-временного развития опускания поверхности в исследуемой области, позволившее определить скорость оседания поверхности с течением времени. Определены горизонтальные перемещения отдельных точек и установлено, что крупные тектонические разломы создают естественный барьер смещениям в массиве. Научная новизна. Использование уникального комплекса методов исследования и мониторинга, примененные в данной работе, позволили точно выявить область проседания поверхности и причины ее образования, а также осуществить мониторинг сейсмической активности в районе, затронутом горными работами. Практическая значимость. Полученные результаты позволяют сравнить современное состояние образовавшейся впадины с ее первоначальными параметрами, а также прогнозировать интенсивность ее развития со временем.This article was written in connection with the Project Institute of Clean Technologies for Mining and Utilization of Raw Materials for Energy Use – Sustainability Program (reg. No.CZ.1.05/2.1.00/03.0082 and MSMT LO1406), which is supported by the Research and Development for Innovations Operational Programme financed by the Structural Funds of the European Union and the Czech Republic project for the longterm conceptual development of research organisations (RVO: 68145535). Many thanks to Dr. Karel Holub, emeritus researcher from the Institute of Geonics of the Czech Academy of Sciences, for his helpful comments and advices during preparation of manuscript. R.I.P

    Evolving a software development methodology for commercial ICTD projects

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    This article discusses the evolution of a “DistRibuted Agile Methodology Addressing Technical Ictd in Commercial Settings” (DRAMATICS) that was developed in a global software corporation to support ICTD projects from initial team setup through ICT system design, development, and prototyping, to scaling up and transitioning, to sustainable commercial models. We developed the methodology using an iterative Action Research approach in a series of commercial ICTD projects over a period of more than six years. Our learning is reflected in distinctive methodology features that support the development of contextually adapted ICT systems, collaboration with local partners, involvement of end users in design, and the transition from research prototypes to scalable, long-term solutions. We offer DRAMATICS as an approach that others can appropriate and adapt to their particular project contexts. We report on the methodology evolution and provide evidence of its effectiveness in the projects where it has been used

    Design of an objective assessment tool to evaluate students' basic electrical engineering skills : the OSTE

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    This report discusses the developmental stage of a Higher Education Academy (HEA) – Engineering Subject Centre project which concerns the designing of an objective assessment tool to evaluate students’ basic electrical engineering skills. The form of assessment is based on the principle of Objective Structured Clinical Examination (OSCE), which is an assessment method already widely adopted in healthcare education. Since it is being used in a different field, this form of OSCE has been named Objective Structured Technical Examination (OSTE). The approach used to develop the exercises included in the OSTE will be discussed. This project will ultimately look at the effectiveness of this method of finding out the basic engineering abilities of a group of students and how it could be used to gear teaching towards any important or specific weaknesses that are discovered among the group.Peer reviewe
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