1,676 research outputs found

    Construction of open innovation ecology on the internet: A case study of Xiaomi (China) using institutional logic

    Get PDF
    The characteristics of collaborative innovation and interactions among core enterprises, users, and partners are critical. Research is lacking on how to construct open innovation ecology through institutional design. This study explores how core enterprises effectively motivate users and partners to participate in innovation activities on the Internet and successfully constructing open innovation ecology, using the institutional logic theory and an exploratory case study of Xiaomi, a famous Chinese Internet enterprise. The findings are as follows: (1) three main characteristics of innovation carried out by core enterprises, users, and partners in the open innovation ecology—iterative innovation, social innovation, and joint innovation; (2) three new institutional practices—following, leading, and symbiotic mechanisms—which provide an effective institutional guarantee for interaction and innovation; (3) two kinds of institutional logic—administrative logic and social logic, which core enterprises follow to construct open innovation ecology on the Internet, and its change in innovation characteristics. Therefore, a full understanding of the changing rules of the institutional logic is fundamental for successfully building open innovation ecology. This study enriches both the open innovation ecology theory as well as the institutional logic theory. In addition, Xiaomi’s open innovation ecological development model proves that core enterprises can take the approach of building open innovation ecology. It provides a strong example to other enterprises on innovations on the Internet

    Framework for contextualized learning ecosystems

    Get PDF
    Proceedings of: 6th European Conference of Technology Enhanced Learning, EC-TEL 2011, Palermo, Italy, September 20-23, 2011Using mobile personal devices to interact with pervasive smart learning objects and services that create contextualized learning ecosystems can enhance both the learning outcomes and the motivational states of students. This paper defines and analyzes several pervasive learning ecosystems in which students at the Carlos III University of Madrid interact with contextualized learning objects and services. The technology defining the contextualized learning environments is first introduced and later used in two user experiments. These experiments provide data both about the learning outcomes for students after interacting with smart learning objects and services and about the motivational impact that the use of these technologies have on themThe research leading to these results has been partially funded by the ARTEMISA project TIN2009-14378-C02-02 within the Spanish "Plan Nacional de I+D+I", the Madrid regional community projects S2009/TIC-1650 and CCG10-UC3M/TIC-4992 and the SOLITE CYTED Program 508AC0341. Thanks to INNOVISION for providing the NFC tags for this experiment. Gustavo Ramirez- Gonzalez is funded by the EU Programme Alban, scholarship number E06D101768CO and by the Universidad del Cauca

    Proof for an upper bound in fixed-node Monte Carlo for lattice fermions

    Get PDF
    We justify a recently proposed prescription for performing Green Function Monte Carlo calculations on systems of lattice fermions, by which one is able to avoid the sign problem. We generalize the prescription such that it can also be used for problems with hopping terms of different signs. We prove that the effective Hamiltonian, used in this method, leads to an upper bound for the ground-state energy of the real Hamiltonian, and we illustrate the effectiveness of the method on small systems.Comment: 14 pages in revtex v3.0, no figure

    How changes in human activities during the lockdown impacted air quality parameters: A review

    Get PDF
    The health emergency linked to the spread of COVID-19 has led to important reduction in industrial and logistics activities, as well as to a drastic changes in citizens' behaviors and habits. The restrictions on working activities, journeys and relationships imposed by the lockdown have had important consequences, including for environmental quality. This review aims to provide a structured and critical evaluation of the recent scientific bibliography that analyzed and described the impact of lockdown on human activities and on air quality. The results indicate an important effect of the lockdown during the first few months of 2020 on air pollution levels, compared to previous periods. The concentrations of particulate matter, nitrogen dioxide, sulfur dioxide and carbon monoxide have decreased. Tropospheric ozone, on the other hand, has significantly increased. These results are important indicators that can become decision drivers for future policies and strategies in industrial and logistics activities (including the mobility sector) aimed at their environmental sustainability. The scenario imposed by COVID-19 has supported the understanding of the link between the reduction of polluting emissions and the state of air quality and will be able to support strategic choices for the future sustainable growth of the industrial and logistics sector

    A quantum Monte Carlo study of the one-dimensional ionic Hubbard model

    Full text link
    Quantum Monte Carlo methods are used to study a quantum phase transition in a 1D Hubbard model with a staggered ionic potential (D). Using recently formulated methods, the electronic polarization and localization are determined directly from the correlated ground state wavefunction and compared to results of previous work using exact diagonalization and Hartree-Fock. We find that the model undergoes a thermodynamic transition from a band insulator (BI) to a broken-symmetry bond ordered (BO) phase as the ratio of U/D is increased. Since it is known that at D = 0 the usual Hubbard model is a Mott insulator (MI) with no long-range order, we have searched for a second transition to this state by (i) increasing U at fixed ionic potential (D) and (ii) decreasing D at fixed U. We find no transition from the BO to MI state, and we propose that the MI state in 1D is unstable to bond ordering under the addition of any finite ionic potential. In real 1D systems the symmetric MI phase is never stable and the transition is from a symmetric BI phase to a dimerized BO phase, with a metallic point at the transition

    Heat and health in Antwerp under climate change: Projected impacts and implications for prevention

    Get PDF
    &lt;p&gt;&lt;b&gt;BACKGROUND: &lt;/b&gt;Excessive summer heat is a serious environmental health problem in several European cities. Heat-related mortality and morbidity is likely to increase under climate change scenarios without adequate prevention based on locally relevant evidence.&lt;/p&gt; &lt;p&gt;&lt;b&gt;METHODS: &lt;/b&gt;We modelled the urban climate of Antwerp for the summer season during the period 1986-2015, and projected summer daily temperatures for two periods, one in the near (2026-2045) and one in the far future (2081-2100), under the Representative Concentration Pathway (RCP) 8.5. We then analysed the relationship between temperature and mortality, as well as with hospital admissions for the period 2009-2013, and estimated the projected mortality in the near future and far future periods under changing climate and population, assuming alternatively no acclimatization and acclimatization based on a constant threshold percentile temperature.&lt;/p&gt; &lt;p&gt;&lt;b&gt;RESULTS: &lt;/b&gt;During the sample period 2009-2013 we observed an increase in daily mortality from a maximum daily temperature of 26°C, or the 89th percentile of the maximum daily temperature series. The annual average heat-related mortality in this period was 13.4 persons (95% CI: 3.8-23.4). No effect of heat was observed in the case of hospital admissions due to cardiorespiratory causes. Under a no acclimatization scenario, annual average heat-related mortality is multiplied by a factor of 1.7 in the near future (24.1deaths/year CI 95%: 6.78-41.94) and by a factor of 4.5 in the far future (60.38deaths/year CI 95%: 17.00-105.11). Under a heat acclimatization scenario, mortality does not increase significantly in the near or in the far future.&lt;/p&gt; &lt;p&gt;&lt;b&gt;CONCLUSION: &lt;/b&gt;These results highlight the importance of a long-term perspective in the public health prevention of heat exposure, particularly in the context of a changing climate, and the calibration of existing prevention activities in light of locally relevant evidence.&lt;/p&gt;</p

    Geodesic motion in the space-time of a cosmic string

    Full text link
    We study the geodesic equation in the space-time of an Abelian-Higgs string and discuss the motion of massless and massive test particles. The geodesics can be classified according to the particles energy, angular momentum and linear momentum along the string axis. We observe that bound orbits of massive particles are only possible if the Higgs boson mass is smaller than the gauge boson mass, while massless particles always move on escape orbits. Moreover, neither massive nor massless particles can ever reach the string axis for non-vanishing angular momentum. We also discuss the dependence of light deflection by a cosmic string as well as the perihelion shift of bound orbits of massive particles on the ratio between Higgs and gauge boson mass and the ratio between symmetry breaking scale and Planck mass, respectively.Comment: 20 pages including 14 figures; v2: references added, discussion on null geodesics extended, numerical results adde

    Transcriptome pathways unique to dehydration tolerant relatives of modern wheat

    Get PDF
    Among abiotic stressors, drought is a major factor responsible for dramatic yield loss in agriculture. In order to reveal differences in global expression profiles of drought tolerant and sensitive wild emmer wheat genotypes, a previously deployed shock-like dehydration process was utilized to compare transcriptomes at two time points in root and leaf tissues using the Affymetrix GeneChip(R) Wheat Genome Array hybridization. The comparison of transcriptomes reveal several unique genes or expression patterns such as differential usage of IP(3)-dependent signal transduction pathways, ethylene- and abscisic acid (ABA)-dependent signaling, and preferential or faster induction of ABA-dependent transcription factors by the tolerant genotype that distinguish contrasting genotypes indicative of distinctive stress response pathways. The data also show that wild emmer wheat is capable of engaging known drought stress responsive mechanisms. The global comparison of transcriptomes in the absence of and after dehydration underlined the gene networks especially in root tissues that may have been lost in the selection processes generating modern bread wheats
    • 

    corecore