Experimental validation of usual numerical models of cracked beams for damage detection approaches

Congreso celebrado en la Escuela de Arquitectura de la Universidad de Sevilla desde el 24 hasta el 26 de junio de 2015.The performances of damage detection approaches are often tested by using numerical solutions of undamaged and damaged structures. However, the numerical results used for a preliminary analysis are useful as far as they can provide a good approach to real experimental results. This paper presents a collection of numerical results obtained from three different finite element models that are extensively used in the literature for the analysis of damage detection approaches, and compare them with experimental results. The paper considers beam, plate and solid models. Natural frequencies and mode shapes of the beams are analyzed. The results show that the results obtained with 1D models are not likely to be well related to a specific experimental test, whereas 2D and 3D models provide good results if the damage is a notch, but, the do not if it is a fatigue crack

Analysis of stationary roving mass effect for damage detection in beams using wavelet analysis of mode shapes

Publicado en Journal of Physics: Conference Series 628 (2015), 012014- . Ghent, Belgium : 24 – 26 August 2015One of the main challenges in damage detection techniques is sensitivity to damage. During the last years, a large number of papers have used wavelet analysis as a sensitive mathematical tool for identifying changes in mode shapes induced by damage. This paper analyzes the e ect of adding a mass to the structure at di erent positions. Depending on the location and severity of damage, the presence of the mass a ects the natural frequencies and mode shapes in a di erent way. The paper applies a damage detection methodology proposed by the authors, although it has been modi ed in order to consider the addition of the mas. This methodology is based on a wavelet analysis of the di erence of mode shapes of a damaged and a reference state. The singular behavior of a normalized weighted addition of wavelet coe cients is used as an indicator of damage. The presence of damage is detected by combining all the information provided by mode shapes and natural frequencies for di erent positions of the roving mass. A continuous wavelet transform is used to detect the di erence between the response of a healthy state and a damaged one. The paper shows the results obtained for a beam with di erent cracks. The paper analyzes the sensitivity to damage of the proposed methodology by considering some practical issues such as the size of the crack, the number of measuring points and the e ect of experimental noise

A Very Low Resource Language Speech Corpus for Computational Language Documentation Experiments

Most speech and language technologies are trained with massive amounts of speech and text information. However, most of the world languages do not have such resources or stable orthography. Systems constructed under these almost zero resource conditions are not only promising for speech technology but also for computational language documentation. The goal of computational language documentation is to help field linguists to (semi-)automatically analyze and annotate audio recordings of endangered and unwritten languages. Example tasks are automatic phoneme discovery or lexicon discovery from the speech signal. This paper presents a speech corpus collected during a realistic language documentation process. It is made up of 5k speech utterances in Mboshi (Bantu C25) aligned to French text translations. Speech transcriptions are also made available: they correspond to a non-standard graphemic form close to the language phonology. We present how the data was collected, cleaned and processed and we illustrate its use through a zero-resource task: spoken term discovery. The dataset is made available to the community for reproducible computational language documentation experiments and their evaluation.Comment: accepted to LREC 201

Design and validation of a tool to assess motor coordination in primary

La coordinación motriz es un proceso evolutivo complejo de adquisición progresiva. La edad óptima para la adquisición de esos procesos coordinativos es de 6 a 11 años (Educación Primaria). El objetivo del presente estudio es diseñar y validar un instrumento que permita evaluar el nivel de coordinación motriz del alumnado Método: Los sujetos son alumnado de Primaria en centros públicos. Muestreo por conveniencia, con una muestra total de 2512 sujetos. Instrumento: Test cualitativo de observación y evaluación objetiva de la ejecución de la habilidad desarrollada en 7 tareas. Resultados: La Consistencia interna (Alfa de Cronbach 0.827), estabilidad temporal (coeficiente correlación: 0.99) y concordancia inter-observadores (coeficiente correlación: 0.95). La validez se comprobó mediante la opinión intuitiva de expertos, siendo la opinión mayoritariamente favorable. Conclusión: El test 3JS es un instrumento fiable, válido y eficaz para medir el desarrollo de la coordinación motriz en el alumnado de 6 a 12 añosMotor coordination is a complex evolutionary process which is gradually acquired. The optimum age for the achievement of these coordination processes is between 6 and 11 years old (Primary Education). The aim of this study is to design and validate a tool which will allow assessing the motor coordination level of the students. Method: Subjects and Sample. Students from Primary Education public schools. ‘Convenience’ sampling, with a total of 2512 subjects. Tool: Qualitative observation test and objective evaluation of the implementation of the abilities developed in 7 tasks. Results: Reliability: Internal Consistency (Cronbach Alpha 0.827), test-retest reliability (correlation coefficient; 0.99) and inter-observer agreement (correlation coefficient; 0.95). Validity has been verified by the experts’ intuitive perception, issuing a largely favourable opinion. Conclusion: The 3JS test is a reliable, valid and effective tool for measuring the motor coordination development in students between 6 and 12 years ol

The MARCONI-3 deep seismic reflection profile: structure of the north Pyrenean foreland at the eastern part of the Bay of Biscay

The MARCONI-3 profile denotes that the structure of the North Pyrenean foreland at the western part of the Parentis Basin consists of a wedge of uppermost Cretaceous to Cenozoic synorogenic sediments lying on the top of a thinned continental crust with a major Mesozoic Basin to the north, the Parentis Basin, and a coeval structural high to the south, the Landes High. The Parentis Basin appears bounded southwards by a major normal fault. It is filled by a thick carbonate succession affected by a salt ridge and diapirs formed during the Albian-Late Cretaceous and squeezed during the late Eocene-middle Miocene. The Landes High includes a thin pre-Upper Cretaceous cover which, together with the synorogenic sediments, is deformed by a thrust wedge that constitutes the north-Pyrenean front. This overall structure evidences that the Mesozoic extension played an important role both in the location and features of the north-Pyrenean contractional deformation. Specially, the Alpine structure in the Parentis Basin denotes that the Landes High acted as a buffer for the north propagation of the Pyrenean deformation until early Miocene and vanished afterwards during the last stages of Pyrenean development when some basement faults reactivated in the Parentis Basin

The North Pyrenean front and related foreland basin along the Bay of Biscay: constrains from the MARCONI deep seismic reflection survey

Profile interpretation of MARCONI seismic profiles show that two domains exist in the Bay of Biscay with a different Pyrenean and north-foreland structure: the eastern, Basque-Parentis and the western, Cantabrian domains. In the eastern one, the North Pyrenean front is located close to the Spanish coast and the northern foreland of the Pyrenees is constituted by a continental crust thinned by Early Cretaceous extensional structures. In the western, Cantabrian domain, the North Pyrenean front is shifted to the north and belongs to a thrust imbricated stack deforming a foreland basin which lies on the top of the Lower Cretaceous oceanic or transitional crust that floors the Bay of Biscay abyssal plain. The coincidence of the transition between these two domains with the eastern border of this abyssal plain denotes that differences along strike of the Pyrenean structure are related to a dramatic change in the nature of the subducted crust from continental to the east, to oceanic or transitional westwards. Thus, the rift system developed between Iberia and Eurasia during the Early Cretaceous appears as a major factor controlling not only the location and features of most of the Pyrenean thrust sheets but also the overall structure of the chain

The deep seismic reflection MARCONI-3 profile: Role of extensional Mesozoic structure during the Pyrenean contractional deformation at the eastern part of the Bay of Biscay

The new MARCONI-3 deep seismic profile allows recognition of the upper crustal structure of the eastern part of the Bay of Biscay and the main features of its Alpine geodynamic evolution. It denotes that the easternmost part of the Bay of Biscay consists of a thick wedge of uppermost Cretaceous to Cenozoic synorogenic sediments lying unconformably on the top of a thinned continental crust with the Mesozoic Parentis Basin to the north and the coeval Landes High to the south. The Parentis Basin appears as a major half-graben bounded southwards by a north-dipping planar fault. It is filled by a thick sequence of Jurassic-Upper Cretaceous carbonates affected by salt domes and squeezed diapirs made up of Triassic evaporites and mudstones. These salt tectonic structures also affect the overlying uppermost Cretaceous to Lower Miocene synorogenic deposits which are folded upon these structures. The Landes High includes a thin pre-Upper Cretaceous cover tilted to the south. In the Basque shelf, it is deformed by a basement-involving thrust wedge emplaced during the Late Eocene- Miocene that constitutes the North-Pyrenean contractional front. Geometric relationships and thickness variations depict that this overall structure results from the following

Functional diversification gave rise to allelic specialization in a rice NLR immune receptor pair

Cooperation between receptors from the nucleotide-binding, leucine-rich repeats (NLR) superfamily is important for intracellular activation of immune responses. NLRs can function in pairs that, upon pathogen recognition, trigger hypersensitive cell death and stop pathogen invasion. Natural selection drives specialization of host immune receptors towards an optimal response, whilst keeping a tight regulation of immunity in the absence of pathogens. However, the molecular basis of co-adaptation and specialization between paired NLRs remains largely unknown. Here, we describe functional specialization in alleles of the rice NLR pair Pik that confers resistance to strains of the blast fungus Magnaporthe oryzae harbouring AVR-Pik effectors. We revealed that matching pairs of allelic Pik NLRs mount effective immune responses, whereas mismatched pairs lead to autoimmune phenotypes, a hallmark of hybrid necrosis in both natural and domesticated plant populations. We further showed that allelic specialization is largely underpinned by a single amino acid polymorphism that determines preferential association between matching pairs of Pik NLRs. These results provide a framework for how functionally linked immune receptors undergo co-adaptation to provide an effective and regulated immune response against pathogens. Understanding the molecular constraints that shape paired NLR evolution has implications beyond plant immunity given that hybrid necrosis can drive reproductive isolation