3,269 research outputs found

    Profile Monitoring of Probability Density Functions via Simplicial Functional PCA with application to Image Data

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    The advance of sensor and information technologies is leading to data-rich industrial environments, where large amounts of data are potentially available. This study focuses on industrial applications where image data are used more and more for quality inspection and statistical process monitoring. In many cases of interest, acquired images consist of several and similar features that are randomly distributed within a given region. Examples are pores in parts obtained via casting or additive manufacturing, voids in metal foams and light-weight components, grains in metallographic analysis, etc. The proposed approach summarizes the random occurrences of the observed features via their (empirical) probability density functions (PDFs). In particular, a novel approach for PDF monitoring is proposed. It is based on simplicial functional principal component analysis (SFPCA), which is performed within the space of density functions, that is, the Bayes space B2. A simulation study shows the enhanced monitoring performances provided by SFPCA-based profile monitoring against other competitors proposed in the literature. Finally, a real case study dealing with the quality control of foamed material production is discussed, to highlight a practical use of the proposed methodology. Supplementary materials for the article are available online

    Design-Time Quantification of Integrity in Cyber-Physical-Systems

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    In a software system it is possible to quantify the amount of information that is leaked or corrupted by analysing the flows of information present in the source code. In a cyber-physical system, information flows are not only present at the digital level, but also at a physical level, and to and fro the two levels. In this work, we provide a methodology to formally analyse a Cyber-Physical System composite model (combining physics and control) using an information flow-theoretic approach. We use this approach to quantify the level of vulnerability of a system with respect to attackers with different capabilities. We illustrate our approach by means of a water distribution case study

    Monitoring wine fermentation using ATR-MIR spectroscopy and chemometric techniques.

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    El vi és un dels productes amb valor afegit més apreciats al món i és per això que el control de la producció vinícola ha sigut sempre un tema prioritari per a la majoria dels cellers. La implementació d’anàlisis at-line com són les Tècniques Analítiques de Processos (PAT), no només permet un control del vi acabat si no que també dóna la possibilitat de prendre mesures correctives al llarg del procés evitant així obtenir un producte final defectuós. En aquesta tesi doctoral, es va investigar la possibilitat d’implementar diferents estratègies per controlar i detectar desviacions durant la fermentació alcohòlica utilitzant un equip portable i de resposta ràpida: un equip d’ espectroscòpia en l’infraroig mitjà, en el mode de reflectància total atenuada (ATR-MIR) el qual permet obtenir, en pocs segons, una gran quantitat d’informació sobre el procés de fermentació que es va tractar amb diferents tècniques quimiomètriques. Primer, utilitzant les dades espectrals i la regressió de mínims quadrats parcials, es van predir diferents paràmetres químics durant la fermentació alcohòlica. En segon lloc, es van comparar els espectres de fermentacions control amb fermentacions desviades utilitzant l’anàlisi discriminant per mínims quadrats parcialsEl vino es uno de los productos con valor añadido más apreciados del mundo y por ello, el control de la producción vinícola ha sido siempre un tema prioritario para la mayoría de bodegas. La implementación de análisis at-line como son las Técnicas Analíticas de Procesos (PAT), no sólo permite un control del vino acabado si no que también brinda la posibilidad de tomar medidas correctivas a lo largo del proceso evitando así obtener un producto final defectuoso. En esta tesis doctoral, se investigó la posibilidad de implementar diferentes estrategias para controlar y detectar desviaciones durante la fermentación alcohólica utilizando un equipo portátil y de respuesta rápida: un equipo de espectroscopia en el infrarrojo medio, en el modo de reflectancia total atenuada (ATR-MIR) el cual permite obtener, en pocos segundos, una gran cantidad de información sobre el proceso de fermentación que se trató con diferentes técnicas quimiométricas. Primero, usando los datos espectrales y la regresión de mínimos cuadrados parciales, se predijeron distintos parámetros químicos durante la fermentación alcohólica. En segundo lugar, se compararon los espectros de fermentaciones control con fermentaciones desviadas utilizando el análisis discriminante por mínimos cuadrados parcialesWine is one of the most appreciated high added-value products in the world and therefore, controlling wine production has always been a priority for most wineries. Implementing at-line analyses such as Process Analytical Technologies (PAT) guidelines, not only enables a control of the final wine but also gives the possibility to apply correcting measures throughout the process, thus avoiding a defective final product. In this doctoral thesis, we investigated the possibility of implementing different strategies to control and detect deviations during wine alcoholic fermentation using a fast and portable equipment: an Attenuated Total Reflectance Mid-Infrared (ATR-MIR) spectrometer which allows obtaining, in a few seconds, a large amount of information about the fermentation process, which was processed with different chemometric techniques. First, using the spectral data and Partial Least Square Regression, different chemical parameters were predicted during alcoholic fermentation. Secondly, we compared the spectra from both Normal Operation Conditions and deviated fermentations using Partial Least Squares Discriminant Analysis. ANOVA–simultaneous component analysis was applied to study the influence of several factors into the variance of the spectra. Multivariate Curve Resolution Alternating Least Squares was used to model both alcoholic and malolactic fermentations. Finally, a PAT methodolog

    Modern day monitoring and control challenges outlined on an industrial-scale benchmark fermentation process

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    This paper outlines real-world control challenges faced by modern-day biopharmaceutical facilities through the extension of a previously developed industrial-scale penicillin fermentation simulation (IndPenSim). The extensions include the addition of a simulated Raman spectroscopy device for the purpose of developing, evaluating and implementation of advanced and innovative control solutions applicable to biotechnology facilities. IndPenSim can be operated in fixed or operator controlled mode and generates all the available on-line, off-line and Raman spectra for each batch. The capabilities of IndPenSim were initially demonstrated through the implementation of a QbD methodology utilising the three stages of the PAT framework. Furthermore, IndPenSim evaluated a fault detection algorithm to detect process faults occurring on different batches recorded throughout a yearly campaign. The simulator and all data presented here are available to download at www.industrialpenicillinsimulation.com and acts as a benchmark for researchers to analyse, improve and optimise the current control strategy implemented on this facility. Additionally, a highly valuable data resource containing 100 batches with all available process and Raman spectroscopy measurements is freely available to download. This data is highly suitable for the development of big data analytics, machine learning (ML) or artificial intelligence (AI) algorithms applicable to the biopharmaceutical industry

    Fast exploration and classification of large hyperspectral image datasets for early bruise detection on apples

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    Hyperspectral imaging allows to easily acquire tens of thousands of spectra for a single sample in few seconds; though valuable, this data-richness poses many problems due to the difficulty of handling a representative amount of samples altogether. For this reason, we recently proposed an approach based on the idea of reducing each image into a one-dimensional signal, named hyperspectrogram, which accounts both for spatial and for spectral information. In this manner, a dataset of hyperspectral images can be easily and quickly converted into a set of signals (2D data matrix), which in turn can be analyzed using classical chemometric techniques. In this work, the hyperspectrograms obtained from a dataset of 800 NIR-hyperspectral images of two different apple varieties were used to discriminate bruised from sound apples using iPLS-DA as variable selection algorithm, which allowed to efficiently detect the presence of bruises. Moreover, the reconstruction as images of the selected variables confirmed that the automated procedure led to the exact identification of the spatial features related to the onset and to the subsequent evolution with time of the bruise defect

    Theoretical Engineering and Satellite Comlink of a PTVD-SHAM System

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    This paper focuses on super helical memory system's design, 'Engineering, Architectural and Satellite Communications' as a theoretical approach of an invention-model to 'store time-data'. The current release entails three concepts: 1- an in-depth theoretical physics engineering of the chip including its, 2- architectural concept based on VLSI methods, and 3- the time-data versus data-time algorithm. The 'Parallel Time Varying & Data Super-helical Access Memory' (PTVD-SHAM), possesses a waterfall effect in its architecture dealing with the process of voltage output-switch into diverse logic and quantum states described as 'Boolean logic & image-logic', respectively. Quantum dot computational methods are explained by utilizing coiled carbon nanotubes (CCNTs) and CNT field effect transistors (CNFETs) in the chip's architecture. Quantum confinement, categorized quantum well substrate, and B-field flux involvements are discussed in theory. Multi-access of coherent sequences of 'qubit addressing' in any magnitude, gained as pre-defined, here e.g., the 'big O notation' asymptotically confined into singularity while possessing a magnitude of 'infinity' for the orientation of array displacement. Gaussian curvature of k(k<0) is debated in aim of specifying the 2D electron gas characteristics, data storage system for defining short and long time cycles for different CCNT diameters where space-time continuum is folded by chance for the particle. Precise pre/post data timing for, e.g., seismic waves before earthquake mantle-reach event occurrence, including time varying self-clocking devices in diverse geographic locations for radar systems is illustrated in the Subsections of the paper. The theoretical fabrication process, electromigration between chip's components is discussed as well.Comment: 50 pages, 10 figures (3 multi-figures), 2 tables. v.1: 1 postulate entailing hypothetical ideas, design and model on future technological advances of PTVD-SHAM. The results of the previous paper [arXiv:0707.1151v6], are extended in order to prove some introductory conjectures in theoretical engineering advanced to architectural analysi

    Applications of acoustics in the measurement of coal slab thickness

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    The determination of the possibility of employing acoustic waves at ultrasonic frequencies for measurements of thicknesses of slabs of coal backed by shale is investigated. Fundamental information concerning the acoustical properties of coal, and the relationship between these properties and the structural and compositional parameters used to characterize coal samples was also sought. The testing device, which utilizes two matched transducers, is described
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