A comparison of machine learning approaches for predicting in-car display production quality

In this paper, we explore eight Machine Learning (ML) approaches (binary and one-class) to predict the quality of in-car displays, measured using Black Uniformity (BU) tests. During production, the industrial manufacturer routinely executes intermediate assembly (screwing and gluing) and functional tests that can signal potential causes for abnormal display units. By using these intermediate tests as inputs, the ML model can be used to identify the unknown relationships between intermediate and BU tests, helping to detect failure causes. In particular, we compare two sets of input variables (A and B) with hundreds of intermediate quality measures related with assembly and functional tests. Using recently collected industrial data, regarding around 147 thousand in-car display records, we performed two evaluation procedures, using first a time ordered train-test split and then a more robust rolling windows. Overall, the best predictive results (92%) were obtained using the full set of inputs (B) and an Automated ML (AutoML) Stacked Ensemble (ASE). We further demonstrate the value of the selected ASE model, by selecting distinct decision threshold scenarios and by using a Sensitivity Analysis (SA) eXplainable Artificial Intelligence (XAI) method.This work is supported by: European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project nº 39479; Funding Reference: POCI-01-0247-FEDER-39479]

La notion d'urbanisation

La notion d’urbanisatio

Lectotipificación y un nuevo sinónimo de Bonamia sericea (Convolvulaceae): Especie endémica de Argentina

Background and aims: Bonamia Thoaurs (Convolvulaceae) comprises about 70 species with a tropical and subtropical distribution. Morphological and molecular studies in Bonamia were carried out to clarify relationships in and out of the genus and throughout this work it was detected the need for re-limit the circumscription of some taxa. This paper contributes to the circumscription and lectotypification of Bonamia sericea (Griseb.) Hallier f., an endemic species from northern Argentina. M&M: Morphological analysis of Bonamia sericea, were made based on a study of specimens of herbaria, including the type-material, digital type images and other herbaria website. Results: A new synonym for B. sericea is proposed. The lectotype of B. sericea is here designated and a complete description and illustrations are presented.Introducción y objetivos: El género Bonamia Thoaurs (Convolvulaceae) comprende alrededor de 70 especies con distribución tropical y subtropical. Durante análisis morfológicos y moleculares de Bonamia se detectó la necesidad de delimitar algunos taxones. Este artículo contribuye a la circunscripción y la lectotipificación de Bonamia sericea (Griseb.) Hallier f., una especie endémica del norte de Argentina. M&M: Análisis morfológico de Bonamia sericea fue realizada mediante préstamo de especimes, incluidos los tipos, y imágenes digitales disponibles en línea, y se compararon con las descripciones originales del taxón. Resultados: Se propone un nuevo sinónimo para B. sericea y se designa su lectotipo. Se realiza una descripción completa de su distribución geográfica.Background and aims: Bonamia Thoaurs (Convolvulaceae) comprises about 70 species with a tropical and subtropical distribution. Morphological and molecular studies in Bonamia were carried out to clarify relationships in and out of the genus and throughout this work it was detected the need for re-limit the circumscription of some taxa. This paper contributes to the circumscription and lectotypification of Bonamia sericea (Griseb.) Hallier f., an endemic species from northern Argentina. M&M: Morphological analysis of Bonamia sericea, were made based on a study of specimens of herbaria, including the type-material, digital type images and other herbaria website. Results: A new synonym for B. sericea is proposed. The lectotype of B. sericea is here designated and a complete description and illustrations are presented

A machine learning approach for spare parts lifetime estimation

Under the Industry 4.0 concept, there is increased usage of data-driven analytics to enhance the production process. In particular, equipment maintenance is a key industrial area that can benefit from using Machine Learning (ML) models. In this paper, we propose a novel Remaining Useful Life (RUL) ML-based spare part prediction that considers maintenance historical records, which are commonly available in several industries and thus more easy to collect when compared with specific equipment measurement data. As a case study, we consider 18,355 RUL records from an automotive multimedia assembly company, where each RUL value is defined as the full amount of units produced within two consecutive corrective maintenance actions. Under regression modeling, two categorical input transforms and eight ML algorithms were explored by considering a realistic rolling window evaluation. The best prediction model, which adopts an Inverse Document Frequency (IDF) data transformation and the Random Forest (RF) algorithm, produced high-quality RUL prediction results under a reasonable computational effort. Moreover, we have executed an eXplainable Artificial Intelligence (XAI) approach, based on the SHapley Additive exPlanations (SHAP) method, over the selected RF model, showing its potential value to extract useful explanatory knowledge for the maintenance domain.- This work has been supported by FCT -Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020

Isolation forests and deep autoencoders for industrial screw tightening anomaly detection

Within the context of Industry 4.0, quality assessment procedures using data-driven techniques are becoming more critical due to the generation of massive amounts of production data. In this paper, we address the detection of abnormal screw tightening processes, which is a key industrial task. Since labeling is costly, requiring a manual effort, we focus on unsupervised detection approaches. In particular, we assume a computationally light low-dimensional problem formulation based on angle–torque pairs. Our work is focused on two unsupervised machine learning (ML) algorithms: isolation forest (IForest) and a deep learning autoencoder (AE). Several computational experiments were held by assuming distinct datasets and a realistic rolling window evaluation procedure. First, we compared the two ML algorithms with two other methods, a local outlier factor method and a supervised Random Forest, on older data related with two production days collected in November 2020. Since competitive results were obtained, during a second stage, we further compared the AE and IForest methods by adopting a more recent and larger dataset (from February to March 2021, totaling 26.9 million observations and related to three distinct assembled products). Both anomaly detection methods obtained an excellent quality class discrimination (higher than 90%) under a realistic rolling window with several training and testing updates. Turning to the computational effort, the AE is much lighter than the IForest for training (around 2.7 times faster) and inference (requiring 3.0 times less computation). This AE property is valuable within this industrial domain since it tends to generate big data. Finally, using the anomaly detection estimates, we developed an interactive visualization tool that provides explainable artificial intelligence (XAI) knowledge for the human operators, helping them to better identify the angle–torque regions associated with screw tightening failures.This work is supported by: European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project n 39479; Funding Reference: POCI-01-0247-FEDER-39479]. The work of Diogo Ribeiro is supported the grant FCT PD/BDE/135105/2017

COMPOSIÇÃO FLORÍSTICA DA FAMÍLIA CONVOVULACEAE EM DIFERENTES BIOMAS DO ESTADO DA BAHIA, BRASIL

Convolvulaceae é uma famí­lia predominantemente tropical e reúne 1.880 espécies. O Brasil é um importante centro de endemismo do grupo, mas sua diversidade ainda é pouco conhecida e subestimada no paí­s. O presente trabalho teve como objetivo listar a composição florí­stica de Convolvulaceae do estado da Bahia.  As espécies foram amostras através das visitas aos herbários, bem como consulta a bancos de dados online. Foram encontrados 196 táxons de Convolvulaceae. O Cerrado foi o bioma mais rico em espécies (147) seguido pela Caatinga (128) e Mata Atlântica (104) entre a similaridade dos biomas. Tendo a Bahia como um estado que apresenta uma grande diversidade para famí­lia é importante entender sobre a diversidade da famí­lia.

Brazilian state debt sustainability : an analysis of net debt and primary balance

A dívida pública é um importante elemento das finanças públicas e sua sustentabilidade é o indicativo da boa gestão da política fiscal de um governo. Este estudo tem o objetivo de verificar a sustentabilidade da dívida estadual, de forma agregada, a partir da análise de cointegração e da reação fiscal entre o resultado primário e a dívida líquida estadual, usando dados mensais de dezembro/2001 a maio/2014. Os resultados apontam a existência de cointegração entre as séries de resultado primário e de dívida líquida estadual e, além disso, revelam que os governos estaduais geraram superávits primários em face do crescimento da dívida. Assim, tem-se a indicação de que existiu sustentabilidade para a dívida dos estados no período estudado. Contudo, desafios recentes como o afrouxamento fiscal e a redução da atividade econômica colocam em dúvida a sustentabilidade futura.Public debt is an important element of governmental finances and its sustainability is an indication of the good management of a government's fiscal policy. This study aims to verify the sustainability of state debt in aggregate form by analyzing the cointegration and fiscal reaction of state primary balance and net debt, using monthly data from December/2001 to May/2014. The results indicate the existence of cointegration between the sets of primary balance and the state net debt, and that state governments have generated primary surpluses in view of state net debt growth. Therefore, there is evidence of debt sustainability concerning state debt during the period under analysis. However, recent challenges such as fiscal slackening and the slowdown in economic activity may make future sustainability uncertain.La deuda pública es un elemento importante de las finanzas públicas y su sostenibilidad es indicativo de una buena gestión de la política fiscal. Así, el estudio tiene como objetivo verificar la sostenibilidad de la deuda estatal en forma agregada, con base en el análisis de cointegración y de reacción fiscal entre el saldo primario y la deuda neta, utilizando datos mensuales de Diciembre/2001 a Mayo/2014. Los resultados demuestran la existencia de cointegración entre las series de resultado primario y la deuda neta del estado y muestran que los gobiernos estatales han generado superávits primarios debido al crecimiento de la deuda. Por lo tanto, existe la indicación de que existía la sostenibilidad de la deuda de los estados durante el período de estudio. Sin embargo, los desafíos recientes, como el aflojamiento fiscal y la reducción de la actividad económica ponen en duda la sostenibilidad futura

Multiculturalismo e trabalho: a proteção do direito de liberdade religiosa de grupos minoritários no Brasil

Developed by the critical-explanatory description method proper of Jurisprudence, the research results from the identification of the need for systematic ordering of legal criteria for the solution of conflicts arising from the confluence of religious diversity elements in the workplace, assuming as hypothesis the existence of a normative protection system of minority religious groups. In order to solve the problem, the general purpose of the research is to analyze, in a multicultural society such as the Brazilian one, the protection scope of the fundamental right to religious freedom of minority groups in the labor relations field. More specifically, it examines the elements related to the exercise of this fundamental right in the workplace, especially in situations of tension. For this, the paper discusses the scope of protection of the fundamental right of religious freedom of minority groups in contractual relations of work, using as theoretical paradigm the circle of dialogic and reflexive interaction between democracy, multiculturalism and work in the context of the Brazilian Democratic State of Law. The study begins with the outline of the expansion of minority religious groups in Brazil. The analysis sets out to critically examine the regulatory framework for the protection of minority groups' right to religious freedom and to fight discrimination related to work. Finally, the study describes the most common conflicts in the dynamic process of intersection between religion and work, developing legal criteria for the solution of these conflicts.Desarrollada por el método de descripción crítico-explicativa propio de la Ciencia del Derecho, la investigación se deriva de la identificación de la necesidad de ordenación sistemática de criterios jurídicos para la solución de conflictos resultantes del encuentro de elementos de diversidad religiosa en el ambiente de trabajo, asumiendo como hipótesis la existencia de un sistema normativo de protección de los grupos religiosos minoritarios. Para la solución del problema, el propósito general de la investigación consiste en analizar, en una sociedad multicultural como la brasileña, el ámbito de protección del derecho fundamental de libertad de religión de los grupos minoritarios en el campo de las relaciones de trabajo. De modo más específico, se examinan los elementos relacionados al ejercicio de ese derecho fundamental en el ambiente del trabajo, especialmente en situaciones de tensión. Para ello, el artículo discute el alcance de la protección del derecho fundamental de libertad religiosa de los grupos minoritarios en las relaciones contractuales de trabajo, utilizando como paradigma teórico el círculo de interacción dialógica y reflexiva entre democracia, multiculturalismo y trabajo en el Estado Democrático de Derecho brasileño. El estudio se inicia al trazar el panorama de la expansión de los grupos religiosos minoritarios en Brasil. El análisis sigue para examinar críticamente el marco de regulación de la protección del derecho de libertad religiosa de los grupos minoritarios y del combate a prácticas de discriminación en el trabajo. Por último, el estudio describe los conflictos más comunes en la intersección entre religión y trabajo, desarrollando criterios jurídicos para la solución de esos conflictos.Desenvolvida pelo método de descrição crítico-explicativa próprio da Ciência do Direito, a pesquisa decorre da identificação da necessidade de ordenação sistemática de critérios jurídicos para a solução de conflitos decorrentes do encontro de elementos de diversidade religiosa no ambiente de trabalho, assumindo como hipótese a existência de sistema normativo de proteção dos grupos religiosos minoritários. Para a solução do problema, o propósito geral da investigação consiste em analisar, em uma sociedade multicultural como a brasileira, o âmbito de proteção do direito fundamental de liberdade de religião dos grupos minoritários no campo das relações de trabalho. De modo mais específico, examinam-se os elementos relacionados ao exercício desse direito fundamental na ambiência do trabalho, sobretudo diante de situações de tensão. Para isso, o artigo discute o alcance da proteção do direito fundamental de liberdade religiosa dos grupos minoritários no âmbito das relações contratuais de trabalho, utilizando como paradigma teórico o círculo de interação dialógica e reflexiva entre democracia, multiculturalismo e trabalho no contexto do Estado Democrático de Direito brasileiro. O estudo se inicia ao traçar o panorama da expansão dos grupos religiosos minoritários no Brasil. A análise parte para examinar criticamente o marco de regulação da proteção do direito de liberdade religiosa dos grupos minoritários e do combate a práticas de discriminação relacionadas ao trabalho. Por fim, o estudo descreve os conflitos mais comuns no processo dinâmico de interseção entre religião e trabalho, desenvolvendo critérios jurídicos para a solução desses conflitos