479 research outputs found

    The Contribution of Global Alliances to Airlines’ Environmental Performance

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    Global alliances have traditionally been related to improvements in the economic and operational performances of companies, particularly in the airline industry. However, we still do not know the effect of the participation in this kind of multilateral agreement on the environmental performance of airlines. The main aim of this work is to analyze whether the alliance membership of airlines has an effect upon their environmental performance, and if so, whether or not the characteristics of the global alliance, as well as the business model of the airline, may influence this relation to a greater or lesser extent. The results of regression and Analysis of Variance (ANOVA) in a sample of 252 airlines (58 included in one of the three global alliances: Star Alliance, Oneworld, and SkyTeam) show a strong and inverse relationship between environmental performance and belonging to an alliance. The paper also shows empirical evidence of the influence of the business model of the airline on environmental performance. These results suggest important implications for managers facing challenges regarding sustainability

    Kernel Methods and their derivatives: Concept and perspectives for the Earth system sciences

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    Kernel methods are powerful machine learning techniques which implement generic non-linear functions to solve complex tasks in a simple way. They Have a solid mathematical background and exhibit excellent performance in practice. However, kernel machines are still considered black-box models as the feature mapping is not directly accessible and difficult to interpret.The aim of this work is to show that it is indeed possible to interpret the functions learned by various kernel methods is intuitive despite their complexity. Specifically, we show that derivatives of these functions have a simple mathematical formulation, are easy to compute, and can be applied to many different problems. We note that model function derivatives in kernel machines is proportional to the kernel function derivative. We provide the explicit analytic form of the first and second derivatives of the most common kernel functions with regard to the inputs as well as generic formulas to compute higher order derivatives. We use them to analyze the most used supervised and unsupervised kernel learning methods: Gaussian Processes for regression, Support Vector Machines for classification, Kernel Entropy Component Analysis for density estimation, and the Hilbert-Schmidt Independence Criterion for estimating the dependency between random variables. For all cases we expressed the derivative of the learned function as a linear combination of the kernel function derivative. Moreover we provide intuitive explanations through illustrative toy examples and show how to improve the interpretation of real applications in the context of spatiotemporal Earth system data cubes. This work reflects on the observation that function derivatives may play a crucial role in kernel methods analysis and understanding.Comment: 21 pages, 10 figures, PLOS One Journa

    Do high-performance human resource practices work? The mediating role of organizational learning capability

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    This study explores the relationship between high-performance human resource practices and organizational outcomes, using organizational learning capability as a mediating variable. By analyzing a sample of 85 Spanish companies in the chemical industry, the results suggest that the application of high-performance human resource practices is positively related to the development of organizational learning capability. This, in turn, is positively related to the financial and non-financial firm’s performance. The mediating role of learning capability is useful and should be considered in studies that analyze the link between human resource practices and performance, a central topic in the literature on strategic human resource management. Additionally, this study provides indications which can help companies design suitable conditions for promoting organizational learning capability, which is directly related to the development of human resource systems

    La integración de los stakeholders en la empresa: identificación de sus principales dimensiones

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    La importancia de los Stakeholders en el mundo empresarial actual hace que las empresas estén obligadas a tenerlos en cuenta, y les provoca la necesidad de realizar esfuerzos en integrar las demandas de sus grupos de interés (GI) en las políticas y prioridades de la firma para conseguir su satisfacción. Tras analizar los distintos aspectos que se han tenido en cuenta para analizar las relaciones con los Stakeholders, y utilizando tanto el enfoque descriptivo como normativo de la teoría, identificamos tres dimensiones en el proceso de integración de los GI: el conocimiento de los GI, su implicación en la empresa a través de la consulta y la participación y la modificación de políticas y objetivos para adaptarse a sus demandas. Estas dimensiones se identifican especialmente relevantes para conseguir la satisfacción de los grupos de interés.The importance of Stakeholders in the current managerial world is forcing companies to keep them continually in mind. In addition, it causes the necessity of carrying out efforts aimed at integrating stakeholders’ demands into their politics and priorities in order to achieve their satisfaction. After analyzing the different aspects considered in the study of relationships with Stakeholders, and using both a descriptive and normative theory scope, we identify three dimensions in the process of stakeholders´ integration: the knowledge about them, their implication in the company through consulting and participation, and finally, the modification of enterprises’ politics and objectives in order to adapt to their demands. These dimensions are considered to be of special importance in ensuring Stakeholders’ satisfaction

    El efecto indirecto sobre el rendimiento de la integración de los stakeholders

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    La literatura, tanto desde el enfoque instrumental como normativo de la Teoría de los Stakeholders, ha resaltado la influencia en el resultado de las relaciones con los grupos de interés (GI), pero este efecto se ha analizado de forma directa. En el presente trabajo, desarrollamos la influencia de la integración de los GI en el rendimiento empresarial, no de forma directa sino indirecta, a través de otras capacidades. Exponemos que la integración de los GI influye de forma indirecta sobre el rendimiento a través de otras capacidades empresariales como la innovación o el aprendizaje organizativo. Además, exponemos que este efecto indirecto se produce de dos formas: bien como elemento potenciador de esas capacidades, o bien como activo complementario sobre el resultado.Existent literature, both from the instrumental as well as the normative Stakeholders’ Theory scope, has highlighted the influence of the relationships with the stakeholders on the enterprises´ performance, but this effect has been analyzed from a direct perspective. In the current paper, we develop the influence of the stakeholders’ integration on the enterprises´ performance, not from a direct way but using an indirect perspective, through other capacities such us innovation, or organizational learning. In addition, we argue that this indirect effect takes place in two ways: as a strengthen element of those capacities, or as a complementary asset on performance

    Open Innovation for Sustainability or Not: Literature Reviews of Global Research Trends

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    The demand for innovative approaches applied to productive sectors is a reality present in the circular economy and open innovation is a relatively new concept that has revolutionized the literature about innovation management. Since the concept appeared in 2003, many articles have focused on its development and application. Although some studies have connected open innovation with sustainability, the relevance of this current on the global literature about open innovation is still unidentified. In this context, this paper tries to cover this gap with a bibliometric analysis focused on the evolution of the open innovation paradigm and the relevance of sustainability in this field of research. A sample of 3087 papers published between 2003 and 2019 in the Scopus database was obtained. The analysis revealed the main topics and the most prolific journals, authors, institutions, and countries, in terms of productivity, citations, and h-indexes. Besides of these contributions, keywords analysis reveals that, in recent years, sustainability and ecosystems are decisive variables in open innovation research

    Charged-particle multiplicities in pp interactions at root s=900 GeV measured with the ATLAS detector at the LHC

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    The first measurements from proton-proton collisions recorded with the ATLAS detector at the LHC are presented. Data were collected in December 2009 using a minimum-bias trigger during collisions at a centre-of-mass energy of 900 GeV. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity, and the relationship between mean transverse momentum and charged-particle multiplicity are measured for events with at least one charged particle in the kinematic range |eta|500 MeV. The measurements are compared to Monte Carlo models of proton-proton collisions and to results from other experiments at the same centre-of-mass energy. The charged-particle multiplicity per event and unit of pseudorapidity at eta = 0 is measured to be 1.333 +/- 0.003 (stat.) +/- 0.040 (syst.), which is 5-15% higher than the Monte Carlo models predict

    Charged-particle multiplicities in pp interactions at root s=900 GeV measured with the ATLAS detector at the LHC

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    22 páginas, 4 figuras, 1 tabla.-- et al.(ATLAS Collaboration).-- arXiv:1003.3124v2The first measurements from proton-proton collisions recorded with the ATLAS detector at the LHC are presented. Data were collected in December 2009 using a minimum-bias trigger during collisions at a centre-of-mass energy of 900 GeV. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity. and the relationship between mean transverse momentum and charged-particle multiplicity are measured for events with at least one charged particle in the kinematic range vertical bar eta vertical bar 500 MeV. The measurements are compared to Monte Carlo models of proton-proton collisions and to results from other experiments at the same centre-of-mass energy. The charged-particle multiplicity per event and unit of pseudorapidity eta = 0 is measured to be 1.333 +/- 0.003(stat.) +/- 0.040(syst.), which is 5-15% higher than the Monte Carlo models predict.We are greatly indebted to all CERN’s departments and to the LHC project for their immense efforts not only in building the LHC, but also for their direct contributions to the construction and installation of the ATLAS detector and its infrastructure. All our congratulations go to the LHC operation team for the superb performance during this initial data-taking period. We acknowledge equally warmly all our technical colleagues in the collaborating Institutions without whom the ATLAS detector could not have been built. Furthermore we are grateful to all the funding agencies which supported generously the construction and the commissioning of the ATLAS detector and also provided the computing infrastructure. The ATLAS detector design and construction has taken about fifteen years, and our thoughts are with all our colleagues who sadly could not see its final realisation. We acknowledge the support of ANPCyT, Argentina; Yerevan Physics Institute, Armenia; ARC and DEST, Australia; Bundesministerium für Wissenschaft und Forschung, Austria; National Academy of Sciences of Azerbaijan; State Committee on Science & Technologies of the Republic of Belarus; CNPq and FINEP, Brazil; NSERC, NRC, and CFI, Canada; CERN; CONICYT, Chile; NSFC, China; COLCIENCIAS, Colombia; Ministry of Education, Youth and Sports of the Czech Republic, Ministry of Industry and Trade of the Czech Republic, and Committee for Collaboration of the Czech Republic with CERN; Danish Natural Science Research Council and the Lundbeck Foundation; European Commission, through the ARTEMIS Research Training Network; IN2P3-CNRS and Dapnia-CEA, France; Georgian Academy of Sciences; BMBF, HGF, DFG and MPG, Germany; Ministry of Education and Religion, through the EPEAEK program PYTHAGORAS II and GSRT, Greece; ISF, MINERVA, GIF, DIP, and Benoziyo Center, Israel; INFN, Italy; MEXT, Japan; CNRST, Morocco; FOM and NWO, Netherlands; The Research Council of Norway; Ministry of Science and Higher Education, Poland; GRICES and FCT, Portugal; Ministry of Education and Research, Romania; Ministry of Education and Science of the Russian Federation and State Atomic Energy Corporation “Rosatom”; JINR; Ministry of Science, Serbia; Department of International Science and Technology Cooperation, Ministry of Education of the Slovak Republic; Slovenian Research Agency, Ministry of Higher Education, Science and Technology, Slovenia; Ministerio de Educación y Ciencia, Spain; The Swedish Research Council, The Knut and Alice Wallenberg Foundation, Sweden; State Secretariat for Education and Science, Swiss National Science Foundation, and Cantons of Bern and Geneva, Switzerland; National Science Council, Taiwan; TAEK, Turkey; The Science and Technology Facilities Council and The Leverhulme Trust, United Kingdom; DOE and NSF, United States of America.Peer reviewe

    Properties of jets measured from tracks in proton-proton collisions at center-of-mass energy sqrt(s) = 7 TeV with the ATLAS detector

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    Jets are identified and their properties studied in center-of-mass energy sqrt(s) = 7 TeV proton-proton collisions at the Large Hadron Collider using charged particles measured by the ATLAS inner detector. Events are selected using a minimum bias trigger, allowing jets at very low transverse momentum to be observed and their characteristics in the transition to high-momentum fully perturbative jets to be studied. Jets are reconstructed using the anti-k(t) algorithm applied to charged particles with two radius parameter choices, 0.4 and 0.6. An inclusive charged jet transverse momentum cross section measurement from 4 GeV to 100 GeV is shown for four ranges in rapidity extending to 1.9 and corrected to charged particle-level truth jets. The transverse momenta and longitudinal momentum fractions of charged particles within jets are measured, along with the charged particle multiplicity and the particle density as a function of radial distance from the jet axis. Comparison of the data with the theoretical models implemented in existing tunings of Monte Carlo event generators indicates reasonable overall agreement between data and Monte Carlo. These comparisons are sensitive to Monte Carlo parton showering, hadronization, and soft physics models

    Measurement of the top quark pair production cross section in pp collisions at sqrt(s) = 7 TeV in dilepton final states with ATLAS

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    A measurement of the production cross section of top quark pairs (t (t) over bar) in proton-proton collisions at a center-of-mass energy of 7 TeV recorded with the ATLAS detector at the Large Hadron Collider is reported. Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. Using a data sample corresponding to an integrated luminosity of 35 pb(-1), a t (t) over bar production cross section sigma(t (t) over bar) = 177 +/- 20(stat.) +/- 14(syst.) +/- 7(lum.) pb is measured for an assumed top quark mass of m(t) = 172.5 GeV. A second measurement requiring at least one jet identified as coming from a b quark yields a comparable result, demonstrating that the dilepton final states are consistent with being accompanied by b-quark jets. These measurements are in good agreement with Standard Model predictions
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