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Evaluating Disruptive Innovation Project Management Capabilities
Full text linkFirms must adapt to a business environment in constant flux. Economic and political factors and the constant interruption of new technologies force firms and organizations to change and to adapt, so that they are not left behind. Over recent years, the development of disruptive innovations has completely revolutionized past scenarios. These innovations break with what is already established and firms from various sectors face no choice other than to incorporate them into their project management portfolios, so as to ensure survival and business sustainability. Using MIVES methodology as its foundation, a business sustainability management model is presented in this paper for the management of disruptive innovation projects that a firm may wish to develop within a given sector. The management model is designed to facilitate disruptive innovation project management for firms within technological-industrial sectors, by assessing the sustainability of the project. The model is applied to two firms, one from the machine-tooling sector and another from the construction sector. Finally, a sensitivity analysis was performed, the results of which verified the validity and the stability of the proposed model
Dual Inertia-Emulation Control for Interlinking Converters in Grid-Tying Applications
Full text linkElectric grids are undergoing several changes, mostly driven by the replacement of classical highly-inertial generators by converter-interfaced generation and storage systems. This entails the reduction of inherent inertia levels and might lead to instability issues. In a future scenario formed by grids of different natures and characteristics, power electronic converters will play a key role on grid tying applications. These converters are known as interlinking converters (ICs), and they enable total control over the power flow between interconnected grids. Therefore, they are envisioned to take part not only tying hybrid ac/dc systems but also in ac/ac connections. This paper presents a novel control strategy for ICs named dual inertiaemulation (DIE), that improves the dynamic response of tied grids by emulating inertia at both sides of the converter, and which can be employed at any IC regardless of the interconnected grid type (ac or dc). The proposed control is tested by means of time-domain simulations of WSCC 9-bus and IEEE 14-bus benchmark systems. The obtained results demonstrate that the proposed technique increases the equivalent inertial response of the interconnected grids, hence reducing frequency oscillations and the rate of change of frequency (RoCoF), and improving the frequency nadir
Analysis of Permanent Magnet Motors in High Frequency: A Review
Full text linkElectric drives consume a great amount of the world’s energy, and it will keep increasing due to the electromobility trend. Thus, the efficiency of electric drives must be improved to reach the desired sustainability goal. The Silicon Carbide devices contribute to this objective due to their high working frequency and lower switching losses. However, working at higher frequencies may bring serious Electromagnetic Compatibility (EMC) problems, as well as insulation stress and higher bearing currents. Hence, it is important to have an electrical machine electrical equivalent circuit model to predict the electromagnetic interference levels. This review summarizes the current state of the art in electrical machine modeling and analysis in high frequency. The main analysis tools as Finite Element Methods, analytic and measurement-based tools are compared in their application on high-frequency electrical machine analysis. Then, different machine high-frequency models are reported, detailing their individual features. Additionally, the influence of the machine design parameters in EMC behavior is outlined for future analysis. All in all, Finite Element analysis is the most accurate tool for high-frequency analysis, provided that mesh size is thinner than the skin depth. It is also concluded that the winding placement is an essential parameter to define the high-frequency behavior of the machine
ETHAZI berrikuntza-ereduan ari diren Lanbide Heziketako irakasleen hezkuntzari buruzko kontzepzioen garapenaren azterketa Covid-19 testuinguruan
Full text linkGeroz eta azkarragoak eta konplexuagoak diren aldaketa ekonomiko, produktibo eta teknologikoei
erantzuteko, Euskal Autonomi Erkidegoko Lanbide Heziketako sisteman ETHAZI hezkuntzaberrikuntza eredua hedatzen ari da. Eredu honen helburu nagusia konpetentzia teknikoen eta
zeharkakoen garapena da, erronka errealetan oinarritutako ikaskuntza eredu kolaboratiboaren bidez.
Artikulu honetan, eredu horren zutabe nagusietako bat diren irakasleen hezkuntzari buruzko
kontzepzioen aldaketa aztertzen da, Covid-19ak sortutako ikaskuntza eta irakaskuntza testuinguru
berriak ETHAZI ereduaren inplementazio maila altua duten ikastetxeetan eredua ezbaian jarri ez
dutenaren inguruko hipotesi berria ondorioztatuz.In response to the increasingly rapid and complex economic, productive and technological changes,
the ETHAZI educational innovation model is being implemented in the Professional Training system of
the Autonomous Community of the Basque Country. The main objective of this model is the development
of both technical and transversal skills through a collaborative learning model based on real challenges.
This article analyzes the modification of the educational conceptions of teachers, one of the fundamental
pillars of this model, deducing the new hypothesis that the new learning and teaching context created
by Covid-19 has not questioned the ETHAZI model in schools with a high degree of implementation of
the model
User preferences and associations with light or dark interfaces
Full text linkLa digitalización nos lleva a estar más horas delante de las pantallas, y por ello, el impacto que tiene en la salud es foco de investigación en la actualidad. En este sentido, la polaridad de contraste juega un papel relevante en el diseño de las interfaces. En la literatura, hay trabajos que comparan la polaridad de contraste en pantallas digitales y obtienen resultados favorables para la polaridad de contraste positiva. Estas investigaciones sobre la legibilidad de las pantallas digitales han demostrado una "ventaja de polaridad positiva”. Sin embargo, la instrumentalidad no es el único valor en una experiencia. La calidad hedónica resulta importante cuando se habla de las experiencias y la percepción de los usuarios. El objetivo de esta investigación es conocer cuál es la percepción de los usuarios ante las interfaces en modo claro u oscuro mediante el Test de Asociación Implícita (IAT) y conocerlo en distinción del género. El test (n=141) ha consistido en dos partes: i) Medida implícita mediante IAT y ii) Medida explicita mediante un cuestionario. Los resultados muestran que el IAT permite conocer la preferencia preexistente de los participantes respecto al modo claro u oscuro, más concretamente, muestra un efecto pequeño hacia el modo claro-positivo
High-Speed Material Characterization Using an Instrumented Forging Hammer
Full text linkHammer forging is a widely employed manufacturing process to produce parts with excellent mechanical properties. Although the rheological behavior and the microstructural transformation phenomena of metals under hammer forging conditions are of great industrial interest, few materials have been tested in such intermediate strain rates (10–103 s−1) due to the lack of laboratory machines for intermediate speed testing. With the objective of addressing that gap, this paper presents a novel automatic forging simulator comprising an instrumented forging hammer capable of performing intermediate speed deformations, up to 5 m/s. Three data acquisition approaches were evaluated to select the most appropriate approach and obtain valid rheological data from intermediate strain rate tests performed on the developed hammer. First, the data obtained by both a high-speed camera and a load cell was combined to calculate reference flow curves. Then, two additional data monitoring approaches were then analyzed, employing independently first the high-speed camera and then the load cell data. It was concluded that flow curves obtained utilizing only the load cell data offered accurate results without the need for an expensive and complex high-speed camera
Mechanical and electrical properties of additively manufactured copper
Full text linkAdditive Manufacturing (AM) has become the new paradigm of design and production strategies. While structural and functional materials are the most implemented ones, it is also possible to manufacture parts using precious metals, being copper one of the most interesting. Among AM technologies, the novel Atomic Diffusion Additive Manufacturing (ADAM) hasrecently included this material between available ones. ADAM is free from thermal and energetic issues caused by high reflectivity and conductivity of copper which other AM encounter. Therefore, it could be a great alternative to manufacture pure copper. In this work ADAM was used to fabricate pure copper specimens in order to measure electrical and mechanical properties. The influence of a machining post processes in strength and ductility is also discussed. Results are compared with wrought C1 1000 copper and published results of other AM technologies. Despite the newness of ADAM, significant improvement in surface roughness and comparable results in other properties was observed. However, further research shall be done to optimize the manufacturing parameters in order to increase the relative density value, as it was found to be significantly lower than in other AM technologies
Numerical characterization of local and global non-uniformities in the load distribution in ball screws
Full text linkLoad distribution in ball screws is a representation of the ball contact stress, and it is fundamental to understanding the behavior of these machine elements. This work aims to conduct a multi-variable analysis of the load distribution in ball screws. For this purpose, a numerical tool is developed for the generation and calculation of ball screw finite element (FE) models, which has been validated against the state of the art. This tool is based on the combination of an analytical contact model and the use of high-order FE models for the analysis of the load distribution of ball screws and stands out for its accuracy (less than 1% error against high-order FE models), adaptability, versatility (models are generated with more than 20 design variables and they can be introduced as components in larger models) and efficiency (being the computational time 1.25% of that of a high-order FE models) with respect to other existing models. Many different design variables (number of start threads, pitch, contact angle, ball size, slenderness and load arrangement) are studied in order to obtain a general characterization of the morphology of the load distribution in ball screws. Among them, the most influential variables on the load distribution and therefore on the structural behavior of ball screws are, load arrangement (with ratio r variations of up to 25% on the same ball screw) and slenderness (with ratio variations of up to 13% on ball screws with two turns of difference). The two most characteristic features, the non-uniformity at a local and global level are identified, along with as the possible causes of their appearance and the consequences that they may cause
Foveal Pit Morphology Characterization: A Quantitative Analysis of the Key Methodological Steps
Full text linkDisentangling the cellular anatomy that gives rise to human visual perception is one of the main challenges of ophthalmology. Of particular interest is the foveal pit, a concave depression located at the center of the retina that captures light from the gaze center. In recent years, there has been a growing interest in studying the morphology of the foveal pit by extracting geometrical features from optical coherence tomography (OCT) images. Despite this, research has devoted little attention to comparing existing approaches for two key methodological steps: the location of the foveal center and the mathematical modelling of the foveal pit. Building upon a dataset of 185 healthy subjects imaged twice, in the present paper the image alignment accuracy of four different foveal center location methods is studied in the first place. Secondly, state-of-the-art foveal pit mathematical models are compared in terms of fitting error, repeatability, and bias. The results indicate the importance of using a robust foveal center location method to align images. Moreover, we show that foveal pit models can improve the agreement between different acquisition protocols. Nevertheless, they can also introduce important biases in the parameter estimates that should be considered
Quasi-static and dynamic crush behaviour of 3D printed thin-walled profiles reinforced with continuous carbon and glass fibres
Full text linkThe present paper investigates the suitability of cFF printed material and technologies for crashworthiness applications. To this end, the quasi-static and dynamic crush behaviour of 3D printed thin-walled hollow profiles reinforced with continuous carbon (cCF/PA) and glass fibres (cGF/PA), in axial and radial loading were analysed. Despite the specific microstrutural differences generated during 3D printing, the nature of the constituents (fibre and matrix) controlled the differences between the crush behaviour of both profiles. Although a stable collapse mode was observed for each profile under quasi-static and impact loading, a ductile response was only reported for the cGF/PA profiles. Under radial quasi-static conditions the cCF/PA profiles showed SEA values greater than the cGF/PAs. Nevertheless, the radial impact performance of the cGF/PA profile was greater as the material presented a strain-rate dependency. The radial SEA values obtained for steered glass fibres were lower than those values obtained for axial loading. However these SEA values are promising, in that they were at least 2–3 times higher than any values found in the literature. The results therefore indicate that concentrically printed cGF/PA reinforcements could be exploited for impact loaded hollow profile applications