542 research outputs found

    The shortcomings of equal weights estimation and the composite equivalence index in PLS-SEM

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    Purpose The purpose of this paper is to assess the appropriateness of equal weights estimation (sumscores) and the application of the composite equivalence index (CEI) vis-à-vis differentiated indicator weights produced by partial least squares structural equation modeling (PLS-SEM). Design/methodology/approach The authors rely on prior literature as well as empirical illustrations and a simulation study to assess the efficacy of equal weights estimation and the CEI. Findings The results show that the CEI lacks discriminatory power, and its use can lead to major differences in structural model estimates, conceals measurement model issues and almost always leads to inferior out-of-sample predictive accuracy compared to differentiated weights produced by PLS-SEM. Research limitations/implications In light of its manifold conceptual and empirical limitations, the authors advise against the use of the CEI. Its adoption and the routine use of equal weights estimation could adversely affect the validity of measurement and structural model results and understate structural model predictive accuracy. Although this study shows that the CEI is an unsuitable metric to decide between equal weights and differentiated weights, it does not propose another means for such a comparison. Practical implications The results suggest that researchers and practitioners should prefer differentiated indicator weights such as those produced by PLS-SEM over equal weights. Originality/value To the best of the authors’ knowledge, this study is the first to provide a comprehensive assessment of the CEI’s usefulness. The results provide guidance for researchers considering using equal indicator weights instead of PLS-SEM-based weighted indicators

    Extraordinary Claims Require Extraordinary Evidence: A Comment on “Recent Developments in PLS”

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    Evermann and Rönkkö (2023) review recent developments in partial least squares (PLS) with the aim of providing guidance to researchers. Indeed, the explosion of methodological advances in PLS in the last decade necessitates such overview articles. In so far as the goal is to provide an objective assessment of the technique, such articles are most welcome. Unfortunately, the authors’ extraordinary and questionable claims paint a misleading picture of PLS. Our goal in this short commentary is to address selected claims made by Evermann and Rönkkö (2023) using simulations and the latest research. Our objective is to bring a positive perspective to this debate and highlight the recent developments in PLS that make it an increasingly valuable technique in IS and management research in general

    First direct mass-measurement of the two-neutron halo nucleus 6He and improved mass for the four-neutron halo 8He

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    The first direct mass-measurement of 6^{6}He has been performed with the TITAN Penning trap mass spectrometer at the ISAC facility. In addition, the mass of 8^{8}He was determined with improved precision over our previous measurement. The obtained masses are mm(6^{6}He) = 6.018 885 883(57) u and mm(8^{8}He) = 8.033 934 44(11) u. The 6^{6}He value shows a deviation from the literature of 4σ\sigma. With these new mass values and the previously measured atomic isotope shifts we obtain charge radii of 2.060(8) fm and 1.959(16) fm for 6^{6}He and 8^{8}He respectively. We present a detailed comparison to nuclear theory for 6^6He, including new hyperspherical harmonics results. A correlation plot of the point-proton radius with the two-neutron separation energy demonstrates clearly the importance of three-nucleon forces.Comment: 4 pages, 2 figure

    First Penning-trap mass measurement in the millisecond half-life range: the exotic halo nucleus 11Li

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    In this letter, we report a new mass for 11^{11}Li using the trapping experiment TITAN at TRIUMF's ISAC facility. This is by far the shortest-lived nuclide, t1/2=8.8mst_{1/2} = 8.8 \rm{ms}, for which a mass measurement has ever been performed with a Penning trap. Combined with our mass measurements of 8,9^{8,9}Li we derive a new two-neutron separation energy of 369.15(65) keV: a factor of seven more precise than the best previous value. This new value is a critical ingredient for the determination of the halo charge radius from isotope-shift measurements. We also report results from state-of-the-art atomic-physics calculations using the new mass and extract a new charge radius for 11^{11}Li. This result is a remarkable confluence of nuclear and atomic physics.Comment: Formatted for submission to PR

    Trapped-ion decay spectroscopy towards the determination of ground-state components of double-beta decay matrix elements

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    A new technique has been developed at TRIUMF's TITAN facility to perform in-trap decay spectroscopy. The aim of this technique is to eventually measure weak electron capture branching ratios (ECBRs) and by this to consequently determine GT matrix elements of ββ\beta\beta decaying nuclei. These branching ratios provide important input to the theoretical description of these decays. The feasibility and power of the technique is demonstrated by measuring the ECBR of 124^{124}Cs.Comment: 9 pages, 9 figure

    Elucidation of the anomalous A = 9 isospin quartet behaviour

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    Recent high-precision mass measurements of 9^{9}Li and 9^{9}Be, performed with the TITAN Penning trap at the TRIUMF ISAC facility, are analyzed in light of state-of-the-art shell model calculations. We find an explanation for the anomalous Isobaric Mass Multiplet Equation (IMME) behaviour for the two AA = 9 quartets. The presence of a cubic dd = 6.3(17) keV term for the JπJ^{\pi} = 3/2^{-} quartet and the vanishing cubic term for the excited JπJ^{\pi} = 1/2^{-} multiplet depend upon the presence of a nearby TT = 1/2 state in 9^{9}B and 9^{9}Be that induces isospin mixing. This is contrary to previous hypotheses involving purely Coulomb and charge-dependent effects. TT = 1/2 states have been observed near the calculated energy, above the TT = 3/2 state. However an experimental confirmation of their JπJ^{\pi} is needed.Comment: 5 pages, 2 figure

    First direct 7^{7}Be electron capture QQ-value measurement towards high-precision BSM neutrino physics searches

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    We report the first direct measurement of the nuclear electron capture (EC) decay QQ-value of 7^{7}Be \rightarrow 7^{7}Li via high-precision Penning trap mass spectrometry (PTMS). This was performed using the LEBIT Penning trap located at the National Superconducting Cyclotron Laboratory/Facility for Rare Isotope Beams (NSCL/FRIB) using the newly commissioned Batch-Mode Ion-Source (BMIS) to deliver the unstable 7^{7}Be+^{+} samples. With a measured value of QECQ_{EC} = 861.963(23) keV this result is also three times more precise than any previous determination of this quantity. This improved precision, and accuracy of the 7^7Be EC decay QQ-value is critical for ongoing experiments that measure the recoiling nucleus in this system as a signature to search for beyond Standard Model (BSM) neutrino physics using 7^7Be-doped superconducting sensors

    Supply chain management resources, capabilities and execution

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    This paper identifies inter- and intra-organisational management resources that determine the level of execution of inter-firm alliance supply chain management (SCM). By drawing on network and resource-based view theories, a conceptual model proposes the effects of SCM resources and capabilities as influencing factors on SCM execution. The model was tested using survey data from studies conducted in two European supply chain environments. Variance-based structural equation modelling confirmed the hypothesised hierarchical order of three proposed antecedents: internal SCM resources affect joint SCM resources, which in turn influence collaborative SCM-related processes and finally SCM execution. An importance-performance analysis for both settings shows that providing and investing in internal SCM resources should be a priority when aiming to increase SCM execution. The theoretical contribution of this paper lies in confirming that the improvement of SCM execution follows a clear pathway featuring internal supply chain resources as one of the main drivers. The practical implications of this research include the development of a prioritisation list of measures that elevate SCM execution in the two country settings
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