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Data Sovereignty for AI Pipelines: Lessons Learned from an Industrial Project at Mondragon Corporation
Full text linkThe establishment of collaborative AI pipelines, in which multiple organizations share their data and models, is often complicated by lengthy data governance processes and legal clarifications. Data sovereignty solutions, which ensure data is being used under agreed terms and conditions, are promising to overcome these problems. However, there is limited research on their applicability in AI pipelines. In this study, we extended an existing AI pipeline at Mondragon Corporation, in which sensor data is collected and subsequently forwarded to a data quality service provider with a data sovereignty component. By systematically reflecting and generalizing our experiences during the twelve-month action research project, we formulated ten lessons learned, four benefits, and three barriers to data-sovereign AI pipelines that can inform further research and custom implementations. Our results show that a data sovereignty component can help reduce existing barriers and increase the success of collaborative data science initiatives
In-situ analysis of the elastic-plastic characteristics of high strength dual-phase steel
Full text linkModeling the elastic behavior of dual-phase steels is complex due to the strain dependency of Young's modulus and high elastic nonlinearity. Since it is assumed that reasons for this are to be found in microstructural behavior, microscopic in-situ analysis are necessary, but due to the overlap of the martensite and ferrite peaks, the evaluation of diffraction profiles is highly complex. Within this work, CR590Y980T (DP1000) is investigated in a continuous cyclic tensile and tension-compression test under synchrotron radiation at High Energy Material Science beamline P07 in Petra III, DESY. On basis of additional EBSD measurements, an evaluation approach is shown to analyze the dual-phase diffraction profiles in such a way that martensite and ferrite can be separated for three lattice planes. The origin of the specific elastic-plastic behavior of dual-phase steels in terms of onset of yielding, anelasticity or early re-yielding is analyzed on the basis of lattice strains and interphase stresses. For this, the time-synchronously measured micro data is correlated with the macro stress-strain relationship and thermoelastic effect. The results help to better understand strain-dependent elastic-plastic behavior of DP steels on a micro level and provide great potential to improve characterization and modeling in terms of springback prediction
Datasets of skills-rating questionnaires for advanced service design through expert knowledge elicitation
Full text linkThis article presents a dataset of service design skills which service design experts value as important requirements for design team members. Purposive sampling and a chain referral approach were used to recruit appropriate experts to conduct questionnaire-based research. Using the analytical hierarchy process (AHP), pairwise skills-rating questionnaires were designed to elicit the experts’ responses. The resulting dataset was processed using AHP algorithms programmed in R programming language. The transparent data and available codes of the research may be reused by design practitioners and researchers for replication and further analysis. This paper offers a reproduceable research process and associated dataset for conducting multiple-criteria decision analysis with expert purposive sampling
Numerical study of advanced friction modelling for sheet metal forming: influence of the die local roughness
Full text linkNumerical simulation of sheet metal forming processes has become indispensable in the last decades. Although the complexity of the frictional behaviour is identified as a key factor for the prediction accuracy, the industry commonly considers a constant friction coefficient for the whole tool. Furthermore, the influence of roughness distribution of the tool in the friction behaviour has not yet been addressed. In this study the influence of the die local roughness in an advanced friction model has been evaluated in three industrial automotive components. The newly implemented advanced friction model (TriboZone) is suggested for advance or mature process verifications
Current References Limitation Method Considering Voltage and Current Maximums for STATCOMs Providing Simultaneously Reactive Power and Current Harmonics
Full text linkThis article focuses the analysis on a static synchronous compensator (STATCOM) that operates simultaneously providing reactive power and several current harmonics of different frequencies (active power filter or active impedance functionalities). Being more specific, this article proposes a general limitation method that reduces the current references of the STATCOM whenever the current or voltage limit of the converter is exceeded. In a realistic operation scenario, the STATCOM’s operator may ask for certain reactive power and harmonic current reference signals, and depending on the actual grid voltage conditions (unbalances and harmonics), the required converter voltage and current may exceed their limit. Consequently, the proposed limitation method protects the STATCOM system from malfunctioning when the voltage limit is exceeded and from damages when the current limit is exceeded. Hence, this article first proposes a limitation method oriented to a STATCOM that operates solely exchanging reactive power. Second, the limitation method is generalized for a STATCOM that controls reactive power as well as several current harmonics. Then, simulation and experimental results are provided to validate the proposed limitation method, under a rich variety of working conditions. Finally, a conceptual analysis of the method is carried out confronting it against several possible limitation alternatives
3D Bioprinted Hydroxyapatite or Graphene Oxide Containing Nanocellulose-Based Scaffolds for Bone Regeneration
Full text linkBone tissue is usually damaged after big traumas, tumors, and increasing aging-related diseases such as osteoporosis and osteoarthritis. Current treatments are based on implanting grafts, which are shown to have several inconveniences. In this regard, tissue engineering through the 3D bioprinting technique has arisen to manufacture structures that would be a feasible therapeutic option for bone regenerative medicine. In this study, nanocellulose–alginate (NC–Alg)-based bioink is improved by adding two different inorganic components such as hydroxyapatite (HAP) and graphene oxide (GO). First, ink rheological properties and biocompatibility are evaluated as well as the influence of the sterilization process on them. Then, scaffolds are characterized. Finally, biological studies of embedded murine D1 mesenchymal stem cells engineered to secrete erythropoietin are performed. Results show that the addition of both HAP and GO prevents NC–Alg ink from viscosity lost in the sterilization process. However, GO is reduced due to short cycle autoclave sterilization, making it incompatible with this ink. In addition, HAP and GO have different influences on scaffold architecture and surface as well as in swelling capacity. Scaffolds mechanics, as well as cell viability and functionality, are promoted by both elements addition. Additionally, GO demonstrates an enhanced bone differentiation capacity
Leisure activities, creative actions and emotional creativity
Full text linkThe general objective of this study was to assess the relationships between leisure, emotional creativity, creative actions, and self-perceptions about creative performances. The sample included 542 participants aged between 18 and 84 years. The instruments used were: (a) Shortened Spanish version of the Emotional Creativity Inventory (ECI-S) for emotional creativity; (b) Creative Actions Scale (CAS) for creative actions; (c) Kaufman Domains of Creativity Scale (K-DOCS) for self-perceptions about creative performances; and (d) a questionnaire for the collection of sociodemographic and leisure data. The results indicated that the actions defined as daily creativity were performed by the individuals with greater frequency. Participants who performed leisure activities achieved higher scores in creative actions and self-perceptions about creative performance. Participants showed greater emotional creativity while performing actions that imply creativity in everyday and scholar settings. People who participate in a committed way in leisure activities have higher scores in ECI-S (Preparedness and Novelty). The analyses indicated differences in the variables analysed according to sex. The observed relationships constitute a relevant contribution of the study to the field of daily and emotional creativity, generating interesting lines for further studies
Basics of Inductive Coupling and Role of Decoupling Capacitors
Full text linkEl acoplamiento electromagnético es el mecanismo con el que un circuito induce ruido o interferencia en otro circuito adyacente.
Este mecanismo de acople genera Interferencias Electromagnéticas que degradan o incluso pueden interrumpir el funcionamiento de circuitos adyacentes. Sin embargo, a menudo, en los ámbitos académicos y profesionales de la electrónica de potencia, es poco común contar con los conocimientos suficientes para identificar y abordar esta problemática. Por lo tanto, la intuición juega un papel importante para prever y lidiar con esta problemática.
En este artículo se describen los principios básicos de este mecanismo de acoplamiento y se proponen soluciones simples a este problema de interferencia electromagnética. Estas soluciones deben aplicarse ya desde la fase del diseño de cualquier equipo de electrónica.
La problemática descrita y sus soluciones se validan experimentalmente en un circuito sencillo de prueba.
Este artículo está orientado principalmente a alumnos y profesionales del ámbito de la electrónica de potencia y pretende describir de forma sencilla y experimentalmente la problemática asociada al acoplamiento inductivo
Parametric Optimisation of a Direct Liquid Cooling–Based Prototype for Electric Vehicles Focused on Pouch-Type Battery Cells
Full text linkIn this work, a numerical optimisation process is applied to improve the fluid dynamical aspect of an innovative direct liquid cooling strategy for lithium-ion–based HEV/EV. First, the thermofluidic numerical model of the battery cell defined by means of CFD computational tools was validated with experimental tests. Then, a comparison between different flow patterns was developed to analyse the influence of the fluid distribution geometry. Finally, a parametric multi-objective optimisation process was implemented arranged by a two-level full factorial design. Considering as input variables the height of the fluid, the number of cooling channels, the number of distributors, and the flow rate, the optimal relationship between the thermal performance of the battery cell, the volumetric energy density of the system, and the power consumption of the strategy was obtained. As a result, the energy density of the system was maximised, and the power consumption was reduced while keeping the cell temperature within the optimal range