1,721,043 research outputs found
A proposal for a quantitative indicator of original research output
No full textThe use of quantitative indicators of scientific productivity seems now quite widespread for assessing researchers and research institutions. There is a general perception, however, that these indicators are not necessarily representative of the originality of the research carried out, being primarily indicative of a more or less prolific scientific activity and of the size of the targeted scientific subcommunity. We first discuss some of the drawbacks of the broadly adopted h-index and of the fact that it represents, in an average sense, an indicator derivable from the total number of citations. Then we propose an indicator which, although not immune from biases, seems more in line with the general expectations for quantifying what is typically considered original work. Qualitative arguments on how different indicators may shape the future of science are finally discussed
State dependence of tunneling processes and thermonuclear fusion
No full textWe discuss the sensitivity of tunneling processes to the initial preparation of the quantum state. We compare the case of Gaussian wave packets of different positional variances using a generalized Woods-Saxon potential for which analytical expressions of the tunneling coefficients are available. Using realistic parameters for barrier potentials we find that the usual plane wave approximation underestimates fusion reactivities by an order of magnitude in a range of temperatures of practical relevance for controlled energy production
Conceptual Understanding of Newtonian Mechanics Through Cluster Analysis of FCI Student Answers
No full textThe Force Concept Inventory is a multiple-choice test and is one of the most popular and most analyzed concept inventories. It is used to investigate student understanding of Newtonian mechanics. A structured approach to data analysis can transform it in a “diagnostic” instrument that can validate inferences about student thinking. In this paper, we show how cluster analysis methods can be used to investigate patterns of student conceptual understanding and supply useful details about the relationships among student concepts and misconceptions. The answers given to the FCI questionnaire by a sample of freshman engineering have been analyzed. The analysis takes into account the decomposition of the force concept into the conceptual dimensions suggested by the FCI authors and successive studies. Our approach identifies latent structures within the student response patterns and groups students characterized by similar correct answers, as well as by non-correct answers. These response patterns give us new insights into the relationships between the student force concepts and their ability to analyze motions. Our results show that cluster analysis proved to be a useful tool to identify latent structures within the student conceptual understanding. Such structures can supply diagnostic insights for classroom pedagogy and teaching approaches
Assessing the influence of personal and organizational factors on surgeon’s performance: A study on surgeons’ perceptions
Full text linkThe Role of Workers’ Representative and OHS Performance: An Interpretative Framework
No full textIn the context of OH&S, the positive role of workers’ representation, involvement and consultation for better OH&S management arrangements is largely discussed in literature; however, the focus is typically on personal traits. The objective of this paper is to expand the scope of previous studies by exploring the relationship between OH&S organizational maturity and the role of workers’ representatives, and consequently the effect on OH&S performance. To this end, a structured questionnaire was administered to a large-scale sample of Italian representatives. Results suggest four types of participative models of organization/representative at different levels of maturity and show clear correlation with OH&S performance
Bounds on charged-lepton flavor violations via resonant scattering
Full text linkWe explore the possibility of probing flavor violations in the charged-lepton sector by means of high-luminosity lepton-photon and electron-muon collisions, by inverting initial and final states in a variety of decay channels presently used to bound such violations. In particular, we analyze the resonant lepton, γl→l′, and neutral-meson, e−μ+→φ,η,π0, scattering channels, whose cross sections are critically dependent on the colliding-beams energy spread, being particularly demanding in the case of leptonic processes. For these processes, we compute upper bounds to the cross-section corresponding to present limits on the inverse decay channel rates. In order to circumvent the beam energy spread limitations we extend the analysis to processes in which a photon accompanies the resonance in the final state, compensating the off-shellness effects by radiative return. These processes might be studied at future facilities with moderate energies, in case lepton-photon and electron-muon collisions with sufficiently high luminosity will be available
OPTIMAL MONITORING OF POSITION IN NONLINEAR QUANTUM-SYSTEMS
No full textWe discuss a model of repeated measurements of position in a quantum system which is monitored for a finite amount of time with a finite instrumental error. In this framework we recover the optimum monitoring of a harmonic oscillator proposed in the case of an instantaneous collapse of the wave function into an infinite-accuracy measurement result. We also establish numerically the existence of an optimal measurement strategy in the case of a nonlinear system. This optimal strategy is completely defined by the spectral properties of the nonlinear system
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