FAULT DIAGNOSIS TOOLS IN MULTIVARIATE STATISTICAL PROCESS AND QUALITY CONTROL

[EN] An accurate fault diagnosis of both, faults sensors and real process faults have become more and more important for process monitoring (minimize downtime, increase safety of plant operation and reduce the manufacturing cost). Quick and correct fault diagnosis is required in order to put back on track our processes or products before safety or quality can be compromised. In the study and comparison of the fault diagnosis methodologies, this thesis distinguishes between two different scenarios, methods for multivariate statistical quality control (MSQC) and methods for latent-based multivariate statistical process control: (Lb-MSPC). In the first part of the thesis the state of the art on fault diagnosis and identification (FDI) is introduced. The second part of the thesis is devoted to the fault diagnosis in multivariate statistical quality control (MSQC). The rationale of the most extended methods for fault diagnosis in supervised scenarios, the requirements for their implementation, their strong points and their drawbacks and relationships are discussed. The performance of the methods is compared using different performance indices in two different process data sets and simulations. New variants and methods to improve the diagnosis performance in MSQC are also proposed. The third part of the thesis is devoted to the fault diagnosis in latent-based multivariate statistical process control (Lb-MSPC). The rationale of the most extended methods for fault diagnosis in supervised Lb-MSPC is described and one of our proposals, the Fingerprints contribution plots (FCP) is introduced. Finally the thesis presents and compare the performance results of these diagnosis methods in Lb-MSPC. The diagnosis results in two process data sets are compared using a new strategy based in the use of the overall sensitivity and specificity[ES] La realización de un diagnóstico preciso de los fallos, tanto si se trata de fallos de sensores como si se trata de fallos de procesos, ha llegado a ser algo de vital importancia en la monitorización de procesos (reduce las paradas de planta, incrementa la seguridad de la operación en planta y reduce los costes de producción). Se requieren diagnósticos rápidos y correctos si se quiere poder recuperar los procesos o productos antes de que la seguridad o la calidad de los mismos se pueda ver comprometida. En el estudio de las diferentes metodologías para el diagnóstico de fallos esta tesis distingue dos escenarios diferentes, métodos para el control de estadístico multivariante de la calidad (MSQC) y métodos para el control estadístico de procesos basados en el uso de variables latentes (Lb-MSPC). En la primera parte de esta tesis se introduce el estado del arte sobre el diagnóstico e identificación de fallos (FDI). La segunda parte de la tesis está centrada en el estudio del diagnóstico de fallos en control estadístico multivariante de la calidad. Se describen los fundamentos de los métodos más extendidos para el diagnóstico en escenarios supervisados, sus requerimientos para su implementación sus puntos fuertes y débiles y sus posibles relaciones. Los resultados de diagnóstico de los métodos es comparado usando diferentes índices sobre los datos procedentes de dos procesos reales y de diferentes simulaciones. En la tesis se proponen nuevas variantes que tratan de mejorar los resultados obtenidos en MSQC. La tercera parte de la tesis está dedicada al diagnóstico de fallos en control estadístico multivariante de procesos basados en el uso de modelos de variables latentes (Lb-MSPC). Se describe los fundamentos de los métodos mas extendidos en el diagnóstico de fallos en Lb-MSPC supervisado y se introduce una de nuestras propuestas, el fingerprint contribution plot (FCP). Finalmente la tesis presenta y compara los resultados de diagnóstico de los métodos propuestos en Lb-MSPC. Los resultados son comparados sobre los datos de dos procesos usando una nueva estrategia basada en el uso de la sensitividad y especificidad promedia.[CA] La realització d'un diagnòstic precís de les fallades, tant si es tracta de fallades de sensors com si es tracta de fallades de processos, ha arribat a ser de vital importància en la monitorització de processos (reduïx les parades de planta, incrementa la seguretat de l'operació en planta i reduïx els costos de producció) . Es requerixen diagnòstics ràpids i correctes si es vol poder recuperar els processos o productes abans de que la seguretat o la qualitat dels mateixos es puga veure compromesa. En l'estudi de les diferents metodologies per al diagnòstic de fallades esta tesi distingix dos escenaris diferents, mètodes per al control estadístic multivariant de la qualitat (MSQC) i l mètodes per al control estadístic de processos basats en l'ús de variables latents (Lb-MSPC). En la primera part d'esta tesi s'introduïx l'estat de l'art sobre el diagnòstic i identificació de fallades (FDI). La segona part de la tesi està centrada en l'estudi del diagnòstic de fallades en control estadístic multivariant de la qualitat. Es descriuen els fonaments dels mètodes més estesos per al diagnòstic en escenaris supervisats, els seus requeriments per a la seua implementació els seus punts forts i febles i les seues possibles relacions. Els resultats de diagnòstic dels mètodes és comparat utilitzant diferents índexs sobre les dades procedents de dos processos reals i de diferents simulacions. En la tesi es proposen noves variants que tracten de millorar els resultats obtinguts en MSQC. La tercera part de la tesi està dedicada al diagnòstic de fallades en control estadístic multivariant de processos basat en l'ús de models de variables latents (Lb-MSPC). Es descriu els fonaments dels mètodes més estesos en el diagnòstic de fallades en MSPC supervisat i s'introdueix una nova proposta, el fingerprint contribution plot (FCP). Finalment la tesi presenta i compara els resultats de diagnòstic dels mètodes proposats en MSPC. Els resultats són comparats sobre les dades de dos processos utilitzant una nova estratègia basada en l'ús de la sensibilitat i especificitat mitjana.Vidal Puig, S. (2016). FAULT DIAGNOSIS TOOLS IN MULTIVARIATE STATISTICAL PROCESS AND QUALITY CONTROL [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61292TESI

Data-driven supervised fault diagnosis methods based on latent variable models: a comparative study

[EN] A comparison among widely used multivariate latent variable-based techniques for supervised process fault diagnosis was carried out. In order to assess their overall performance several diagnosis criteria were proposed (C-1: most suspected fault assignment; C-2: threshold-based fault assignment). Additionally, it was evaluated i) how the size of the training set used to build the latent variable models affected the diagnosis ability of the methods under study, ii) how they behaved under new types of failures not included in the original list of fault candidates and iii) which of them were more suitable for either early or late diagnosis. To accomplish all these objectives, the approaches were tested in different scenarios. Two datasets were analysed: the first was generated by a Simulink-based model of a binary distillation column, while the second relates to a pasteurisation process performed in a laboratory-scale plant.This research work was partially supported by the Spanish Ministry of Economy and Competitiveness under the project DPI2017-82896-C2-1-R and Shell Global Solutions International B.V. (Amsterdam, The Netherlands).Vidal-Puig, S.; Vitale, R.; Ferrer, A. (2019). Data-driven supervised fault diagnosis methods based on latent variable models: a comparative study. Chemometrics and Intelligent Laboratory Systems. 187:41-52. https://doi.org/10.1016/j.chemolab.2019.02.006S415218

¿Los estudiantes de primer curso de grado pueden trabajar competencias transversales en la asignatura Estadística?

Las universidades españolas están trabajando para que sus egresados posean competencias transversales, altamente demandadas hoy en día para comenzar su vida laboral, cuando concluyan sus estudios de grado. Pero, para que el alumnado esté formado en tales competencias, hay que trabajarlas. En el presente artículo se presenta la acción que se ha realizado con las TIC, en concreto un blog, dentro de la asignatura Estadística, en el que los estudiantes trabajan diferentes competencias transversales. A partir de un blog colaborativo (son autores tanto la profesora como sus alumnos y alumnas que así lo desean), creado para divulgar aplicaciones prácticas de la materia que se estudia, se ha llegado a un entorno en el que se desarrollan diferentes competencias transversales

No metabolic effects of mustard allyl-isothiocyanate compared with placebo in men.

Background: Induction of nonshivering thermogenesis can be used to influence energy balance to prevent or even treat obesity. The pungent component of mustard, allyl-isothiocyanate (AITC), activates the extreme cold receptor transient receptor potential channel, subfamily A, member 1 and may thus induce energy expenditure and metabolic changes.Objective: The objective of our study was to evaluate the potential of mustard AITC to induce thermogenesis (primary outcome) and alter body temperature, cold and hunger sensations, plasma metabolic parameters, and energy intake (secondary outcomes).Design: Energy expenditure in mice was measured after subcutaneous injection with vehicle, 1 mg norepinephrine/kg, or 5 mg AITC/kg. In our human crossover study, 11 healthy subjects were studied under temperature-controlled conditions after an overnight fast. After ingestion of 10 g of capsulated mustard or uncapsulated mustard or a capsulated placebo mixture, measurements of energy expenditure, substrate oxidation, core temperature, cold and hunger scores, and plasma parameters were repeated every 30 min during a 150-min period. Subjects were randomly selected for the placebo and capsulated mustard intervention; 9 of 11 subjects received the uncapsulated mustard as the final intervention because this could not be blinded. After the experiments, energy intake was measured with the universal eating monitor in a test meal.Results: In mice, AITC administration induced a 32% increase in energy expenditure compared with vehicle (17.5 ± 4.9 J · min-1 · mouse-1 compared with 12.5 ± 1.2 J · min-1 · mouse-1, P = 0.03). Of the 11 randomly selected participants, 1 was excluded because of intercurrent illness after the first visit and 1 withdrew after the second visit. Energy expenditure did not increase after ingestion of capsulated or uncapsulated mustard compared with placebo. No differences in substrate oxidation, core temperature, cold and hunger scores, or plasma parameters were found, nor was the energy intake at the end of the experiment different between the 3 conditions.Conclusion: The highest tolerable dose of mustard we were able to use did not elicit a relevant thermogenic response in humans. This trial was registered at www.controlled-trials.com as ISRCTN19147515

Un estudio sobre la utilidad de la realización de prácticas de laboratorio en el proceso de aprendizaje y su influencia en los resultados de la evaluación del alumno

En el presente trabajo, realizado en la Escuela Técnica Superior de Informática Aplicada (ETSIAp) de la Universidad Politécnica de Valencia, se ha analizado el efecto que la realización de las prácticas de la asignatura de Estadística tiene sobre la nota final del examen. Para dicho estudio se han empleado dos técnicas estadísticas complementarias

COVID-19 Impact: A Case Study at the School of Agricultural Engineering and Environment of the Universitat Politècnica de València

[EN] To study the first impact of the COVID-19 crisis on the results obtained by students belonging to the School of Agricultural Engineering and Environment at the Universitat Politecnica de Valencia (Spain), the average of the marks corresponding to three academic years (2016-2019) was compared to those obtained in 2019-2020 for a total of four bachelor's degrees and two semesters. Our results suggest a positive effect on the marks obtained during the activation of emergency remote teaching during the spring semester of 2019-2020 in three out of the four degrees, with these differences being significant for the whole study. Moreover, just at the end of that period, instructors and students were surveyed regarding teaching methodologies, evaluation modalities, and difficulties found throughout the process of adapting to distance teaching. Our results allow us to sensibly think about that exceptional situation in order to propose a set of counterweighting measures which could improve the implementation of distance learning in engineering colleges.Clemente Polo, G.; Garcia-Prats, A.; Lisón, P.; Rubio Michavila, C.; Vidal-Puig, S.; Ricarte Benedito, B.; Estruch-Guitart, V.... (2022). COVID-19 Impact: A Case Study at the School of Agricultural Engineering and Environment of the Universitat Politècnica de València. Sustainability. 14(17):1-14. https://doi.org/10.3390/su141710607114141

Distance Learning In Time Of Crisis: A Case Study At The School Of Agricultural Engineering And Environment Of Universitat Politècnica De València

[EN] Higher education is continuously evolving to keep up with the challenges posed by the introduction of information and communication technologies (ICT) to education. In this sense, distance learning is booming, with an increasing number of higher education students taking advantage of the flexibility remote learning provides. The School of Agricultural Engineering and Environment (ETSIAMN) of Universitat Politècnica de València (UPV) has been gradually incorporating ICT tools in its bachelor and master degrees for the last two decades. As a result, many college students and university instructors are familiar with ICT techniques. However, the unprecedented COVID-19 crisis has put distance learning in the spotlight like never before, forcing students, faculty, and staff to adapt to the new situation with hardly any preparation time. For that reason, it is convenient to analyse in depth the results and impact of the teaching and evaluation methodologies developed and applied during this critical period, as a way to detect and amend potential inefficiencies in the learning process. The specific goal of this study was to analyse the teaching period during the COVID-19 crisis in ETSIAMN, which covered the spring semester of the academic year 2019-2020. To this purpose, 114 instructors and 274 students were surveyed in July 2020, belonging to four bachelor degrees (agricultural and biological engineering; forestry engineering; food engineering; and biotechnology), and three master degrees (agricultural and biological engineering; forestry engineering, and oenology). Regarding the experimental design for the survey, three main blocks were identified: the first block corresponds to teaching methodologies, comparing students and faculty preferences for distance lecturing; the second block focuses on evaluation modalities and exam configurations; and the final block centers on the difficulties found by both students and lecturers along the adaptation process from conventional to distance teaching. Results showed that instructors and students preferred a combination of live streaming with recorded lectures, being multiple choice the favourite examination type, although many students rated first a project-based evaluation. Overall, students rejected tests with no possibilities to go back on already answered questions, and instructors mostly preferred limiting the time to complete the on-line tests. The lack of motivation was the main barrier encountered by students to achieve an effective learning. Finally, a set of counterweighting measures to improve and promote the successful implementation of distance learning in engineering colleges is proposed.Clemente Polo, G.; Garcia-Prats, A.; Lisón, P.; Rubio Michavila, C.; Ricarte Benedito, B.; Estruch-Guitart, V.; Fenollosa Ribera, ML.... (2020). Distance Learning In Time Of Crisis: A Case Study At The School Of Agricultural Engineering And Environment Of Universitat Politècnica De València. IATED Academy. 3938-3945. https://doi.org/10.21125/iceri.2020.0889S3938394

Desarrollo de una metodología para la formación y evaluación “continua” en pensamiento crítico

[EN] In this study, we shall describe a teaching experience carried out by a group of lecturers in the Statistics Department. These lecturers are involved in the training and assessment of “critical thinking” skills as part of the institutional project centred on generic skills at the Universitat Politècnica de València. The objective of this experience was to promote the understanding, development and application of the critical thinking skills in the students. Different activities linked to the abilities involved in critical thinking are proposed to the students throughout the academic year. The activities require ongoing assessment from the formative point of view. Thus, the students are aware of their own progress. Additionally, students are evaluated in the exams with questions in different formats (PoliformaT exams, tests and peer review). Suitable materials and activities for training and assessment of critical thinking have been developed. Finally the teaching staff and the students’ opinions have been collected through surveys.[ES] En este trabajo se presenta la experiencia realizada por un grupo de profesores del Departamento de Estadística en diversas asignaturas que son punto de control de la competencia "Pensamiento Crítico”. El objetivo de la experiencia era guiar a los alumnos para que entendiesen el pensamiento crítico, lo desarrollasen y lo aplicasen. Durante el curso los alumnos han realizado actividades que trabajan diferentes habilidades vinculadas con dicha competencia. Estas actividades han sido evaluadas de tal manera que desde el punto de vista formativo, el alumno sea consciente de su progreso en la competencia. Adicionalmente se les ha evaluado en los exámenes con cuestiones bajo formatos diversos (exámenes PoliformaT, preguntas en pruebas escritas y corrección por pares). Se han creado materiales y actividades adaptadas para la formación y evaluación del pensamiento crítico y a través de encuestas se ha constatado que el profesorado y el alumnado ha valorado positivamente la metodología empleada.Vidal Puig, S.; Barceló Cerdá, S.; Calduch Llosa, Á.; Debón Aucejo, AM.; Calduch Losa, MDLA.; Villa Juliá, MF. (2018). Desarrollo de una metodología para la formación y evaluación “continua” en pensamiento crítico. En IN-RED 2018. IV Congreso Nacional de Innovación Educativa y Docencia en Red. Editorial Universitat Politècnica de València. 1462-1476. https://doi.org/10.4995/INRED2018.2018.8736OCS1462147

BMP8B increases brown adipose tissue thermogenesis through both central and peripheral actions

Thermogenesis in brown adipose tissue (BAT) is fundamental to energy balance and is also relevant for humans. Bone morphogenetic proteins (BMPs) regulate adipogenesis, and, here, we describe a role for BMP8B in the direct regulation of thermogenesis. BMP8B is induced by nutritional and thermogenic factors in mature BAT, increasing the response to noradrenaline through enhanced p38MAPK/CREB signaling and increased lipase activity. Bmp8b(-/-) mice exhibit impaired thermogenesis and reduced metabolic rate, causing weight gain despite hypophagia. BMP8B is also expressed in the hypothalamus, and Bmp8b(-/-) mice display altered neuropeptide levels and reduced phosphorylation of AMP-activated protein kinase (AMPK), indicating an anorexigenic state. Central BMP8B treatment increased sympathetic activation of BAT, dependent on the status of AMPK in key hypothalamic nuclei. Our results indicate that BMP8B is a thermogenic protein that regulates energy balance in partnership with hypothalamic AMPK. BMP8B may offer a mechanism to specifically increase energy dissipation by BAT

Factors associated with the development of septic shock in patients with candidemia: a post hoc analysis from two prospective cohorts

[Background] Almost one third of the patients with candidemia develop septic shock. The understanding why some patients do and others do not develop septic shock is very limited. The objective of this study was to identify variables associated with septic shock development in a large population of patients with candidemia.[Methods] A post hoc analysis was performed on two prospective, multicenter cohort of patients with candidemia from 12 hospitals in Spain and Italy. All episodes occurring from September 2016 to February 2018 were analyzed to assess variables associated with septic shock development defined according to The Third International Consensus Definition for Sepsis and Septic Shock (Sepsis-3).[Results] Of 317 candidemic patients, 99 (31.2%) presented septic shock attributable to candidemia. Multivariate logistic regression analysis identifies the following factors associated with septic shock development: age > 50 years (OR 2.57, 95% CI 1.03–6.41, p = 0.04), abdominal source of the infection (OR 2.18, 95% CI 1.04–4.55, p = 0.04), and admission to a general ward at the time of candidemia onset (OR 0.21, 95% CI, 0.12–0.44, p = 0.001). Septic shock development was independently associated with a greater risk of 30-day mortality (OR 2.14, 95% CI 1.08–4.24, p = 0.02).[Conclusions] Age and abdominal source of the infection are the most important factors significantly associated with the development of septic shock in patients with candidemia. Our findings suggest that host factors and source of the infection may be more important for development of septic shock than intrinsic virulence factors of organisms.This study was funded by a research grant from the Ministerio de Sanidad y Consumo, Instituto de Salud Carlos III [FIS PI15/00744], European Regional Development Fund (ERDF); CGV is a recipient of an INTENSIFICACIÓ Grant from the “Strategic plan for research and innovation in health-PERIS 2016-2020” and forms part of the Fungi CLINIC Research group (AGAUR-Project 2017SGR1432 of the Catalan Health Agency)