444 research outputs found

    Containing the Not-Invented-Here Syndrome in external knowledge absorption and open innovation: The role of indirect countermeasures

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    This paper builds new theory and provides supporting evidence to contain the Not-Invented-Here Syndrome (NIHS) – a persistent decision-making error arising from an attitude-based bias against external knowledge. Conceptually, we draw on the 4i framework of organizational learning to develop a novel process perspective on NIHS. This allows us not only to unpack how and where NIHS impedes organizational learning, but also to identify the key requirements for effective NIHS countermeasures. Importantly, countermeasures fall into two categories: those that seek to change the negative attitude directly (direct NIHS countermeasures) and those that seek to attenuate the behavioral impact of negative attitudes without addressing the attitudes as such (indirect NIHS countermeasures). While the evidence base on direct NIHS countermeasures has grown over the last decade, indirect NIHS countermeasures have received little research attention. To address this gap, we adopt a mixed methods research design composed of two complementary empirical studies – the first qualitative and the second quantitative. Study 1 explores the prevalence of distinct NIHS countermeasures in collaborative R&D practice. Based on 32 interviews and three focus group meetings with R&D employees, we find that a broad array of primarily direct NIHS countermeasures is employed in R&D practice. Study 2 addresses the scarcity of scholarly and managerial insights on indirect NIHS countermeasures by testing the effectiveness of perspective taking as a debiasing technique to contain negative attitudes at the level of the individual. Based on quantitative survey data from 565 global R&D projects, it provides empirical evidence not only for the prevalence and negative effects of NIHS on project success as mediated by external knowledge absorption, but also for the effectiveness of perspective taking as an exemplary indirect NIHS countermeasure

    Economic Implications of Additive Manufacturing and the Contribution of MIS

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    This is the author accepted manuscript. The final version is available from Springer at http://link.springer.com/article/10.1007%2Fs12599-015-0374-4

    Diffractive Phenomena and Shadowing in Deep-Inelastic Scattering

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    Shadowing effects in deep-inelastic lepton-nucleus scattering probe the mass spectrum of diffractive leptoproduction from individual nucleons. We explore this relationship using current experimental information on both processes. In recent data from the NMC and E665 collaboration, taken at small x << 0.1 and Q^2 < 1 GeV^2, shadowing is dominated by the diffractive excitation and coherent interaction of low mass vector mesons. If shadowing is explored at small x > 1 GeV^2 as discussed at HERA, the situation is different. Here dominant contributions come from the coherent interaction of diffractively produced heavy mass states. Furthermore we observe that the energy dependence of shadowing is directly related to the mass dependence of the diffractive production cross section for free nucleon targets.Comment: 12 pages Latex, 8 figure

    Nuclear shadowing at low photon energies

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    We calculate the shadowing effect in nuclear photoabsorption at low photon energies (1-3 GeV) within a multiple scattering approach. We avoid some of the high energy approximations that are usually made in simple Glauber theory like the narrow width and the eikonal approximation. We find that the main contribution to nuclear shadowing at low energies stems from ρ0\rho^0 mesons with masses well below their pole mass. We also show that the possibility of scattering in non forward directions allows for a new contribution to shadowing at low energies: the production of neutral pions as intermediate hadronic states enhances the shadowing effect in the onset region. For light nuclei and small photon energies they give rise to about 30% of the total shadowing effect.Comment: RevTeX, 16 pages including 6 eps figures; new calculation of effective pion propagator, negligible effect on results; version to be published in Phys. Rev.

    Resummation of nuclear enhanced higher twist in the Drell Yan process

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    We investigate higher twist contributions to the transverse momentum broadening of Drell Yan pairs in proton nucleus collisions. We revisit the contribution of matrix elements of twist-4 and generalize this to matrix elements of arbitrary twist. An estimate of the maximal nuclear broadening effect is derived. A model for nuclear enhanced matrix elements of arbitrary twist allows us to give the result of a resummation of all twists in closed form. Subleading corrections to the maximal broadening are discussed qualitatively.Comment: 10 pages, 5 figures; v2: minor changes in text, acknowledgement added; v3: mistake in fig. 1 correcte

    Quark exchange model for charmonium dissociation in hot hadronic matter

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    A diagrammatic approach to quark exchange processes in meson-meson scattering is applied to the case of inelastic reactions of the type (Q\barQ)+(q\barq)\rightarrow (Q\barq) + (q\barQ), where QQ and qq refer to heavy and light quarks, respectively. This string-flip process is discussed as a microscopic mechanism for charmonium dissociation (absorption) in hadronic matter. The cross section for the reaction J/ψ+πD+DˉJ/\psi + \pi \to D+ \bar D is calculated using a potential model, which is fitted to the meson mass spectrum. The temperature dependence of the relaxation time for the \J/Psi distribution in a homogeneous thermal pion gas is obtained. The use of charmonium for the diagnostics of the state of hot hadronic matter produced in ultrarelativistic nucleus-nucleus collisions is discussed.Comment: 24 pages, 3 tables, 7 figure

    Significance of climate and hydrochemistry on shape variation – a case study on Neotropical cytheroidean Ostracoda

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    How environmental change affects a species' phenotype is crucial not only for taxonomy and biodiversity assessments but also for its application as a palaeo-ecological and ecological indicator. Previous investigations addressing the impact of the climate and hydrochemical regime on ostracod valve morphology have yielded contrasting results. Frequently identified ecological factors influencing carapace shape are salinity, cation, sulfate concentrations, and alkalinity. Here, we present a thorough approach integrating data with the carapace outline and surface details of the ubiquitous Neotropical cytheroidean ostracod species Cytheridella ilosvayi, as well as several climatic and hydrochemical variables, in order to investigate a potential link between morphology and environmental conditions. A recent study previously demonstrated considerable biogeographical variation in valve morphology among Floridian, Mexican and Brazilian populations of this species. We hypothesize that the climatic differences between the regions it inhabits and associated differences in hydrochemical regimes have influenced valve morphology and eventually led to biogeographically distinctive groups. Generalized least-squares Procrustes analyses based on outline and structural features were applied to the left and right valves of adult females and males. The analyses identified relative carapace length and shape symmetry as most important morphological characteristics representing shape differences across all datasets. Two-block partial least-squares analyses and multiple regressions indicate strong relationships between morphological and environmental variables, specifically with temperature seasonality, annual precipitation and chloride and sulfate concentrations. We suggest that increased temperature seasonality slowed down growth rates during colder months, potentially triggering the development of shortened valves with well-developed brood pouches. Differences in chloride and sulfate concentrations, related to fluctuations in precipitation, are considered to affect valve development via controlling osmoregulation and carapace calcification. The factors identified by our analyses represent hitherto unknown drivers for ostracod ecophenotypy in other species and therefore suggest that environmental predictors for morphological variability are not consistent across non-marine ostracods.</p

    Charmonium suppression from purely geometrical effects

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    The extend to which geometrical effects contribute to the production and suppression of the J/ψJ/\psi and qqˉq\bar{q} minijet pairs in general is investigated for high energy heavy ion collisions at SPS, RHIC and LHC energies. For the energy range under investigation, the geometrical effects referred to are shadowing and anti-shadowing, respectively. Due to those effects, the parton distributions in nuclei deviate from the naive extrapolation from the free nucleon result; fAAfNf_{A}\neq A f_{N}. The strength of the shadowing/anti-shadowing effect increases with the mass number. The consequences of gluonic shadowing effects for the xFx_F distribution of J/ψJ/\psi's at s=20\sqrt s =20 GeV, s=200\sqrt s =200 GeV and s=6\sqrt s =6 TeV are calculated for some relevant combinations of nuclei, as well as the pTp_T distribution of minijets at midrapidity for Nf=4N_f=4 in the final state.Comment: corrected some typos, improved shadowing ratio

    Shadowing in the nuclear photoabsorption above the resonance region

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    A model based on the hadronic fluctuations of the real photon is developed to describe the total photonucleon and photonuclear cross sections in the energy region above the nucleon resonances. The hadronic spectral function of the photon is derived including the finite width of vector-meson resonances and the quark-antiquark continuum. The shadowing effect is evaluated considering the effective interaction of the hadronic component with the bound nucleons within a Glauber-Gribov multiple scattering theory. The low energy onset of the shadowing effect is interpreted as a possible signature of a modification of the hadronic spectral function in the nuclear medium. A decrease of the ρ\rho-meson mass in nuclei is suggested for a better explanation of the experimental data.Comment: 8 pages, 7 figure

    Shadowing, Binding and Off-Shell Effects in Nuclear Deep Inelastic Scattering

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    We present a unified description of nuclear deep inelastic scattering (DIS) over the whole region 0<x<10<x<1 of the Bjorken variable. Our approach is based on a relativistically covariant formalism which uses analytical properties of quark correlators. In the laboratory frame it naturally incorporates two mechanisms of DIS: (I) scattering from quarks and antiquarks in the target and (II) production of quark-antiquark pairs followed by interactions with the target. We first calculate structure functions of the free nucleon and develop a model for the quark spectral functions. We show that mechanism (II) is responsible for the sea quark content of the nucleon while mechanism (I) governs the valence part of the nucleon structure functions. We find that the coherent interaction of qˉq\bar qq pairs with nucleons in the nucleus leads to shadowing at small xx and discuss this effect in detail. In the large xx region DIS takes place mainly on a single nucleon. There we focus on the derivation of the convolution model. We point out that the off-shell properties of the bound nucleon structure function give rise to sizable nuclear effects.Comment: 29 pages (and 10 figures available as hard copies from Authors), REVTE
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