3,012 research outputs found

    Tailored particle current in an optical lattice by a weak time-symmetric harmonic potential

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    Quantum ratchets exhibit asymptotic currents when driven by a time-periodic potential of zero mean if the proper spatio-temporal symmetries are broken. There has been recent debate on whether directed currents may arise for potentials which do not break these symmetries. We show here that, in the presence of degeneracies in the quasienergy spectrum, long-lasting directed currents can be induced, even if the time reversal symmetry is not broken. Our model can be realized with ultracold atoms in optical lattices in the tight-binding regime, and we show that the time scale of the average current can be controlled by extremely weak fields.Comment: 4 pages, 4 figure

    Gamification and entrepreneurial intentions

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    Purpose – The purpose of this paper is to investigate how gamification can influence entrepreneurial intentions (EI) of a group of users of an online platform provided by a private company.Design/methodology/approach – A quantitative research strategy was used with a sample of 220 respondents. These respondents were tested before and after the gamification experience.Findings – Main findings support literature suggesting a clear effect of attitudes towards behaviour and perceived behavioural control on EI, in line with the theory of planned behaviour (TPB). Once the basic assumptions of TPB were confirmed, the authors tested the effects of gamification comparing before and after results. Main findings highlight an increase of these effects after the gamification experience, aligned with the self-determination theory.Practical implications – These findings suggest that gamification is able to influence entrepreneurial behaviours. This contributes to both companies and educators’ knowledge on training for EI with gamification and the use of online platforms to this effect. Recommendations are provided.Originality/value – This is the first study that investigates the impact of gamification on EI and howgamification can influence the different relationships between the antecedents of EI

    Au-Cu/SBA(Ti) based catalysts for photocatalytic applications

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    Comunicación a congresoIn this work, it has been synthesized several Au and Au-Cu alloy photocatalysts supported on two different mesoporous supports: a non-commercial SBA-15 and a post-synthesis TiO2 modified SBA-15 (TiSBA-15), with which a high dispersion of TiO2 species have been achieved maintaining the SBA-15 structure. In addition, it has also been obtained highly dispersed Au nanoparticles confined in SBA-15 pore channels, as can be observed in Figure 1. The photocatalysts have been preliminary tested in the preferential CO oxidation in a H2-rich stream (CO-PROX) at room temperature and atmospheric pressure under simulated solar light irradiation. In spite of the very low gold and copper loading (1.5 wt% and 0.5wt% respectively), the catalysts resulted active and selective in the low temperature photo-CO-PROX.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tec

    Museum visitors’ heterogeneity and experience processing

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    This research examines the relationships between affective and cognitive antecedents and consequences of satisfaction under a market heterogeneity approach. It includes co-creation of preparatory activities. The sample consisted of 276 museum visitors in London. Two analysis have been conducted: structural equation model and latent class path analysis. The paper contributes to the development of a theoretical framework for further understanding of service experience in which co-creation plays an important role. Two segments were identified: 1) emotional (with lower degree of co-creation, equally distributed by age and nationality); 2) rational (higher degree of co-creation, younger and domestic visitors). Our research shows significant differences between the two segments regarding variables such as satisfaction, loyalty, service experience, emotion, positive disconfirmation and willingness to pay more

    Servitization strategies from customers’ perspective: the moderating role of co-creation

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    © 2018, Emerald Publishing Limited. Purpose: This paper aims to investigate the moderating role of co-creation in the implementation of servitization strategies in the pharmaceutical industry in a business-to-business (B-to-B) context. More specifically, this investigation explores the impact of different levels of services (base, intermediate and advanced) on servitization and on performance by using co-creation as a moderating factor. Design/methodology/approach: A research framework was developed and empirically tested in the pharmaceutical sector. Data collection was conducted through the online distribution of questionnaires. The final sample included 219 pharmacy stores, and the data were analysed using structural equation modelling. Findings: Main findings suggest that when the level of co-creation of the design of services is high, there are significant effects of servitization on firm performance. The moderating effect of co-creation is illustrated in regard to intermediate and advanced services, but results referring to the impact of intermediate services on servitization appear non-significant with a low degree of co-creation. No significant effects could be found for the impact of base services on performance and servitization for both high and low degrees of co-creation. Findings show an impact of advanced services on performance through the mediating effect of servitization when the degree of co-creation is high. Originality/value: Most research concerning servitization has been done from the perspective of manufacturers and service providers. This study adds value to the literature because it was designed from a customer’s perspective. Moreover, it contributes towards the conceptualization of the servitization research strategy and business models in a B2B context. This is accomplished through the investigation of the moderating effect of co-creation on the impact of the different levels of services on servitization and on performance

    Role of Mo in catalysts based on noble metals in hydrodeoxygenation reactions

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    The use of bio-energy as a renewable alternative to fossil fuels is nowadays attracting more and more attention. The bio-fuel from biomass seems to be a potential energy substitute for fossil fuels since it is a renewable resource that could contribute to sustainable development and global environmental preservation and it appears to have significant economic potential1. The problem is its high oxygen content, which gives undesirable properties for combustion. To remove oxygen, catalytic hydrodeoxygenation (HDO) reactions are carried out. Monometallic Mo/Si, Pt/Si as well as bimetallic PtMo/Si catalysts were prepared and evaluated in the hydrodeoxygenation (HDO)reaction of dibenzofurane (DBF) as a model molecule in biomass derived bio-oil.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Deformation mechanism map of Cu/Nb nanoscale metallic multilayers as a function of temperature and layer thickness

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    The mechanical properties and deformation mechanisms of Cu/Nb nanoscale metallic multilayers (NMMs) manufactured by accumulative roll bonding (ARB) are studied at 25C and 400C. Cu/Nb NMMs with individual layer thicknesses between 7 and 63 nm were tested by in-situ micropillar compression inside a scanning electron microscope Yield strength, strain-rate sensitivities and activation volumes were obtained from the pillar compression tests. The deformed micropillars were examined under scanning and transmission electron microscopy in order to examine the deformation mechanisms active for different layer thicknesses and temperatures. The analysis suggests that room temperature deformation was determined by dislocation glide at larger layer thicknesses and interface-related mechanisms at the thinner layer thicknesses. The high temperature compression tests, in contrast, revealed superior thermo-mechanical stability and strength retention for the NMMs with larger layer thicknesses with deformation controlled by dislocation glide. A remarkable transition in deformation mechanism occurred as the layer thickness decreased, to a deformation response controlled by diffusion processes along the interfaces, which resulted in temperature-induced softening. A deformation mechanism map, in terms of layer thickness and temperature, is proposed from the results obtained in this investigation

    A general approach for computing a consensus in group decision making that integrates multiple ethical principles

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    [EN] We tackle the problem of computing a consensus according to multiple ethical principles - which can include, for example, the principle of maximum freedom associated with the Benthamite doctrine and the principle of maximum fairness associated with the Rawlsian principles - among the preferences of different individuals in the context of Group Decision-Making (GDM). More formally, we put forward a novel formalisation of the above-mentioned problem based on a multi-lp-norm approximation problem that aims at minimising multiple p-metric distance functions, where each parameter p represents a given ethical principle. Our contribution incurs obvious benefits from a social-choice perspective. Firstly, our approach significantly generalises stateof-the-art approaches that were limited to only two ethical principles (p = 1, for maximum freedom, and p = & INFIN;, for maximum fairness). Secondly, our experimental results considering an established test case demonstrate that our approach is capable, thanks to a novel re-weighting scheme, to compute a multi-norm consensus that takes into account each ethical principle in a balanced way, in contrast with state-of-the-art approaches that were heavily biased towards the p =1 ethical principle.Research supported by projects: CI-SUSTAIN, Spain (PID2019-104156GB-I00) ; TAILOR, Spain (H2020-952215) ; 2021 SGR 00754 funded by Generalitat de Catalunya, Spain; VAE TED2021-131295B-C31, funded by MCIN/AEI, Spain/10.13 039/501100011033 and NextGenerationEU/PRTR, Spain; and VALAWAI, Spain (Horizon Europe #101070930) . Funding for open access charge: CRUE-Universitat Politecnica de Valencia.Salas-Molina, F.; Bistaffa, F.; Rodríguez-Aguilar, JA. (2023). A general approach for computing a consensus in group decision making that integrates multiple ethical principles. Socio-Economic Planning Sciences. 89. https://doi.org/10.1016/j.seps.2023.1016948

    Histopathological image analysis for breast cancer diagnosis by ensembles of convolutional neural networks and genetic algorithms

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    One of the most invasive cancer types which affect women is breast cancer. Unfortunately, it exhibits a high mortality rate. Automated histopathological image analysis can help to diagnose the disease. Therefore, computer aided diagnosis by intelligent image analysis can help in the diagnosis tasks associated with this disease. Here we propose an automated system for histopathological image analysis that is based on deep learning neural networks with convolutional layers. Rather than a single network, an ensemble of them is built so as to attain higher recognition rates, which are obtained by computing a consensus decision from the individual networks of the ensemble. A final step involves the optimization of the set of networks that are included in the ensemble by a genetic algorithm. Experimental results are provided with a set of benchmark images, with favorable outcomes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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