Material grain noise analysis by using higher-order statistics

Miralles, Ramón; Vergara, Luis; Gosalbez, J.

doi:10.1016/j.sigpro.2003.10.007

Cited by 23 publications

(13 citation statements)

References 14 publications

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“…A maximum entropy model of spectral analysis also had limited success (Hargreaves 1988). Miralles et al (2004) discuss the application of higher order statistics (HOS) for analyzing ultrasonic backscatter. Though the focus of the work is on classifying scatterer (or grain) sizes based on HOS, similar approaches may potentially be applied to improve SNR or characterize microstructure.…”

Section: Figure 43 Nominal and Faulted Gaussian Distributionsmentioning

confidence: 99%

Prognostics and Health Management in Nuclear Power Plants: A Review of Technologies and Applications

Coble¹,

Ramuhalli²,

Bond³

et al. 2012

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Recent years have seen a resurgence of nuclear power worldwide, with interest in extending the operating life of the approximately 436 reactors currently in service (as of March, 2012), 61 new reactors being constructed, and as many as 162 under consideration. Renewed worldwide interest in nuclear power has been somewhat tempered by the March 2011 incident at Fukushima Dai-ichi in Japan. However, nuclear power is still considered a key element in meeting future worldwide sustainable energy, energy security, and emissions goals. Currently, three separate thrusts to safe and economical nuclear power development for energy security are being pursued in the United States: (i) longer term operation for the legacy fleet, from 40-60 and possibly 60-80 years; (ii) near-term new nuclear plants with a 60-year design life; and (iii) small modular reactors, which are expected to employ light water reactor technology at least in the medium term. Within these activities, attention is turning to enhanced methods for plant component and structural health management.The operating U.S. fleet includes 104 light water reactors. In addition, there are now (as of May 2012) four new nuclear power plants (AP-1000 plants) under construction in the United States, and two delayed plants are being completed by the Tennessee Valley Authority. There is also interest in the United States in small modular reactors (SMRs), which could be easier to match to existing grid infrastructure and which could replace aging coal fired plants. The current low price for natural gas presents a challenge to the economics of nuclear power, at least in the short term; however, some recent studies have demonstrated that nuclear generation will be competitive in the longer term (at least in some markets) when anticipated escalation in gas prices and the cost of building, operating, and maintaining gas-fired plants are considered over those same time periods.This report reviews the current state of the art of prognostics and health management (PHM) for nuclear power systems and related technology currently applied in field or under development in other technological application areas, as well as key research needs and technical gaps for increased use of PHM in nuclear power systems. The historical approach to monitoring and maintenance in nuclear power plants (NPPs), including the Maintenance Rule for active components and Aging Management Plans for passive components, are reviewed. An outline is given for the technical and economic challenges that make PHM attractive for both legacy plants through Light Water Reactor Sustainability (LWRS) and new plant designs. There is a general introduction to PHM systems for monitoring, fault detection and diagnostics, and prognostics in other, non-nuclear fields. The state of the art for health monitoring in nuclear power systems is reviewed. A discussion of related technologies that support the application of PHM systems in NPPs, including digital instrumentation and control systems, wired and wireless sensor techno...

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Section: Figure 43 Nominal and Faulted Gaussian Distributionsmentioning

confidence: 99%

Prognostics and Health Management in Nuclear Power Plants: A Review of Technologies and Applications

Coble¹,

Ramuhalli²,

Bond³

et al. 2012

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“…Cumulants have been modelled in order to characterize propagation of ultrasound in materials [6]. Other HOS tools, like the bicepstrum, have been successfully used in blind identification of acoustic emissions [7].…”

Section: Introductionmentioning

confidence: 99%

Higher-order spectra measurement techniques of termite emissions. A characterization framework

Rosa¹,

Lloret²,

Puntonet³

et al. 2008

Measurement

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Section: Firma Ultrasónicaunclassified

“…Por otro lado enfatizar que las ventajas de aplicación del estimador ω mod c se acentúan para el caso de materiales más atenuantes (ver gráficas 4.17.có 4. 19.c), ya que en estos casos el sesgo y varianza del estimador ω c es mayor que en el caso de aplicación a materiales menos atenuantes. Para clarificar este punto se puede consultar la gráficas 4.…”

Section: Sesgo (Marcador '*' O 'O') Y Varianza (Barras Verticalesunclassified

“…Sin embargo, la deconvolución se convierte en un problema mal condicionado cuando las señales son paso-banda, y por otra parte los estadísticos de la reflectividad sólo sonútiles en el caso de existir no gaussianidad. Otra posibilidad consiste en obtener los estadísticos de la reflectividad a través de la relación directa entre los estadísticos de la señal registrada (salida del LTV) y los estadísticos de la señal de entrada al LTV [10,19], pero los estadísticos de la reflectividad sólo sonútiles en el caso de existir no gaussianidad.El estudio de la variación temporal de las características de nuestro modelo implica la realización de un análisis no estacionario de la señal recibida, tal cual se desarrollará en el capítulo 2. En la figura 1.6 se muestra un esquema general válido para los dos tipos de problemas descritos en el punto anterior.…”

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Descriptores Geométricos y de Forma: Aplicación a la caracterización ultrasónica de materiales

García¹

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Among other applications, the Grupo de Tratamiento de Señal (GTS) of the Universidad Politécnica de Valencia has traditionally researched in the field of non-destructive testing using ultrasounds. The GTS has developed sophisticated algorithms about processing signals for further detection and characterization in scattering materials.The ultrasonic inspection process implies getting a register or signal using an ultrasound pulser-receiver equipment. This register is further processed in order to get information about the material. The compilation of characteristics can be done by computing temporary parameters and/or of frequency about the obtained registers. These parameters contain information related to physics properties of the materials and that will be finally susceptible of being used to classify and characterize the material.The aim of this PhD thesis is to expand the set of parameters that this group has been using in a traditional way. The new parameters propose a change of perspective by using techniques based on a digital image processing. The thesis shows a collection of shape and geometric descriptors that will be applied to the images got from the time-frequency diagrams. Theses parameters will be applied with the parameters that were part of the traditional model, or modified versions of these ones, to the ultrasonic characterization of soft scattering materials.The PhD thesis presents a common mathematical model for the materials that have been evaluated in this research. The ultrasonic register obtained from the ultrasonic inspection is then modeled in the frequency domain. With the purpose of carrying the spectral analysis of the ultrasonic signal, different methods are considered and studied, besides, different alternatives for the computation and improvement of the time-frequency diagrams are discussed.A study about the frequently used parameter estimators in the frequency domain has been done. Moreover, we have proposed some modifications of these estimators from the digital image processing point of view. Besides, a suitable simulator for the mathematical model presented has been developed. The objective of the simulator is to perform a comparative between the conventional estimators and their corresponding modified and the checking of the effectiveness of the improvement proposals.Finally, a study of shape and geometric descriptors proposed in this PhD thesis is realized and its utility to the characterization of different kinds of soft scattering materials is validated. It has been also proved the utility of the new set of proposed parameters so as to characterize these types of materials. A mis padres AgradecimientosA mis padres. Gracias por apoyarme y creer en mi en todo momento. Porque sois unos buenos padres y mejores personas, porque los intereses de vuestros hijos siempre han estado por encima de los vuestros propios, porque gracias a vuestro trabajo y esfuerzo incondicional hoy tengo lo que tengo. Gracias a vuestra forma de ser y pensar hoy sigo luchando, mirando hacia del...

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Material grain noise analysis by using higher-order statistics

Cited by 23 publications

References 14 publications

Prognostics and Health Management in Nuclear Power Plants: A Review of Technologies and Applications

Prognostics and Health Management in Nuclear Power Plants: A Review of Technologies and Applications

Higher-order spectra measurement techniques of termite emissions. A characterization framework

Descriptores Geométricos y de Forma: Aplicación a la caracterización ultrasónica de materiales

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