1,721,438 research outputs found
Fiscal decentralization, regional inequality and bailout : lessons from Brazil's debt crisis
No full textThis paper develops a simple two-period model of public good provision within a federation. A national public good is provided to both states by the federal government, while a local public good is supplied by each state government. The federal government levies a proportional income tax, and in each period the state governments receive a share of the revenues collected equal to the amount needed to finance the first best provision of the local public good. In the first period the local governments can also use borrowing to finance the provision of the public good, but any debt contracted must be repaid in the second period. We show that when the states face a hard budget constraint, they do not find it optimal to increase the provision of the local public good above the first best level guaranteed by the federal grant. However, if the federal government cannot credibly commit not to bail-out the states, then the local governments may find it optimal to borrow in order to increase the provision of the public good above the first best in the first period. Furthermore, we show that the commitment problem is more likely to arise vis-á-vis states whose default results in a negative externality on the federation. Hence, those states are more likely to carry on budget deficits and benefit from a federal bail-ou
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Investigating aeroelastic and aeroacoustic responses of wind turbines using large-eddy simulations
No full textThis thesis investigates the aeroelastic and aeroacoustic behavior of large-scale wind turbines through high-fidelity numerical simulations, offering new insights into their aerodynamic performance, wake dynamics, and noise emissions. A detailed aeroelastic study is conducted on the NREL 5-MW and IEA 15-MW wind turbines, comparing their structural responses under different inflow conditions using a coupled Computational Fluid Dynamics (CFD) and Computational Structural Dynamics (CSD) approach and benchmarking the results against OpenFAST. The fluid model is based on the incompressible Navier-Stokes equations solved using Large-Eddy Simulation (LES), with the Actuator Line Model (ALM) employed to represent the aerodynamic forces exerted by the turbine blades. The structural model relies on a geometrically exact nonlinear beam formulation, ensuring an accurate representation of the blade deformations under aerodynamic and inertial loads. The study highlights significant discrepancies between high-fidelity and Blade Element Momentum (BEM)-based solvers, particularly in local incidence and blade deformation, with OpenFAST underestimating the impact of tower shadowing effects. Additionally, preliminary results assess the response of the IEA 15-MW turbine under a turbulent inflow, providing initial observations on the role of turbulence intensity in modifying aerodynamic loads and structural deflections. To further explore the influence of turbine size on wake dynamics, a Dynamic Mode Decomposition (DMD) analysis is performed under identical turbulent Atmospheric Boundary Layer (ABL) conditions. The results demonstrate that larger turbines exhibit lower-frequency wake structures, confirming that rotor size acts as a filter on coherent structures while also amplifying tip vortex-related high-frequency modes, thereby influencing wake evolution and recovery. In parallel, the aeroacoustic characteristics of the NREL 5-MW turbine are examined by coupling LES with the Ffowcs Williams-Hawkings (FWH-P) acoustic analogy, allowing for the identification of dominant aerodynamic modes contributing to tonal and broadband noise. The application of Sparsity-Promoting Dynamic Mode Decomposition (SPDMD) further enables a low-dimensional representation of the flow field, revealing key frequencies responsible for noise generation. The findings of this thesis contribute to the advancement of wind turbine modeling by improving the accuracy of predictive tools for aeroelastic response, wake development, and noise emissions, supporting the design of more efficient and quieter wind energy systems
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Liquid-liquid extraction of zirconium with tributylacetohydroxamic acid and spectrophotometric determination in the organic phase with Xylenol orange
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Use of high-molecular-weith "neo" Hidroxamic acids as the stationary phase in column extraction chromatography
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