254 research outputs found
Alternativas para el futuro político y económico de Europa
Este artículo póstumo del profesor William A. Niskanen compara con clarividencia las cuatro posibilidades de asociación que tiene ante sí la Unión Europea utilizando el criterio de cuál de estas formas de asociación consigue las máximas economías de escala. Después de señalar las sombras
y las luces de la Unión Económica en áreas como la agricultura, la defensa, la política medioambiental, comercial y monetaria, y la de investigación, propone como la solución más viable el conformar
Europa como una asociación de Estados europeos independientes dispuestos a llevar a cabo medidas de integración selectivas y voluntarias.This posthumous article by Professor William A. Niskanen clairvoyantly compares the four association
possibilities faced by the European Union, using as criteria which of these forms of
association attain the highest scale economies. After depicting the shadows and lights of the Economic Union in sectors such as agriculture, defence, environmental, commercial and monetary policies, and research policies, he sets forth as the most feasible solution, to constitute Europe as an association of
independent European States prepared to implement selective and voluntary integration measures
Self-interest And Public Interest: The Motivations Of Political Actors
Self-Interest and Public Interest in Western Politics showed that the public, politicians, and bureaucrats are often public spirited. But this does not invalidate public-choice theory. Public-choice theory is an ideal type, not a claim that self-interest explains all political behavior. Instead, public-choice theory is useful in creating rules and institutions that guard against the worst case, which would be universal self-interestedness in politics. In contrast, the public-interest hypothesis is neither a comprehensive explanation of political behavior nor a sound basis for institutional design
Large-amplitude driving of a superconducting artificial atom: Interferometry, cooling, and amplitude spectroscopy
Superconducting persistent-current qubits are quantum-coherent artificial
atoms with multiple, tunable energy levels. In the presence of large-amplitude
harmonic excitation, the qubit state can be driven through one or more of the
constituent energy-level avoided crossings. The resulting
Landau-Zener-Stueckelberg (LZS) transitions mediate a rich array of
quantum-coherent phenomena. We review here three experimental works based on
LZS transitions: Mach-Zehnder-type interferometry between repeated LZS
transitions, microwave-induced cooling, and amplitude spectroscopy. These
experiments exhibit a remarkable agreement with theory, and are extensible to
other solid-state and atomic qubit modalities. We anticipate they will find
application to qubit state-preparation and control methods for quantum
information science and technology.Comment: 13 pages, 5 figure
Governance, Coordination and Evaluation: the case for an epistemological focus and a return to C.E. Lindblom
While much political science research focuses on conceptualizing and analyzing various forms of governance, there remains a need to develop frameworks and criteria for governance evaluation (Torfing et al 2012). The post-positivist turn, influential in recent governance theory, emphasizes the complexity, uncertainty and the contested normative dimensions of policy analysis. Yet a central evaluative question still arises concerning the capacity of governance networks to facilitate ‘coordination’. The classic contributions of Charles Lindblom, although pre-dating the contemporary governance literature, can enable further elaboration of and engagement with this question. Lindblom’s conceptualisation of coordination challenges in the face of complexity shares with post-positivism a recognition of the inevitably contested nature of policy goals. Yet Lindblom suggests a closer focus on the complex, dynamically evolving, broadly ‘economic’ choices and trade-offs involved in defining and delivery policy for enabling these goals to be achieved and the significant epistemological challenges that they raise for policy-makers. This focus can complement and enrich both post-positivist scholarship and the process and incentives-orientated approaches which predominate in contemporary political science research on coordination in governance. This is briefly illustrated through a short case study evaluating governance for steering markets towards delivering low and zero carbon homes in England
Amplitude Spectroscopy of a Solid-State Artificial Atom
The energy-level structure of a quantum system plays a fundamental role in
determining its behavior and manifests itself in a discrete absorption and
emission spectrum. Conventionally, spectra are probed via frequency
spectroscopy whereby the frequency \nu of a harmonic driving field is varied to
fulfill the conditions \Delta E = h \nu, where the driving field is resonant
with the level separation \Delta E (h is Planck's constant). Although this
technique has been successfully employed in a variety of physical systems,
including natural and artificial atoms and molecules, its application is not
universally straightforward, and becomes extremely challenging for frequencies
in the range of 10's and 100's of gigahertz. Here we demonstrate an alternative
approach, whereby a harmonic driving field sweeps the atom through its
energy-level avoided crossings at a fixed frequency, surmounting many of the
limitations of the conventional approach. Spectroscopic information is obtained
from the amplitude dependence of the system response. The resulting
``spectroscopy diamonds'' contain interference patterns and population
inversion that serve as a fingerprint of the atom's spectrum. By analyzing
these features, we determine the energy spectrum of a manifold of states with
energies from 0.01 to 120 GHz \times h in a superconducting artificial atom,
using a driving frequency near 0.1 GHz. This approach provides a means to
manipulate and characterize systems over a broad bandwidth, using only a single
driving frequency that may be orders of magnitude smaller than the energy
scales being probed.Comment: 12 pages, 13 figure
Beyond Environmental Regulatory Fragmentation: Signs of Integration in the Case of the Great Lakes Basin
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72007/1/j.1468-0491.1995.tb00197.x.pd
Quantum bits with Josephson junctions
Already in the first edition of this book (Barone and Paterno, "Fundamentals
and Physics and Applications of the Josephson Effect", Wiley 1982), a great
number of interesting and important applications for Josephson junctions were
discussed. In the decades that have passed since then, several new applications
have emerged. This chapter treats one such new class of applications: quantum
optics and quantum information processing (QIP) based on superconducting
circuits with Josephson junctions. In this chapter, we aim to explain the
basics of superconducting quantum circuits with Josephson junctions and
demonstrate how these systems open up new prospects, both for QIP and for the
study of quantum optics and atomic physics.Comment: 30 pages, 10 figures. Book chapter for a new edition of Barone and
Paterno's "Fundamentals and Physics and Applications of the Josephson
Effect". Final versio
A volumetric technique for fossil body mass estimation applied to Australopithecus afarensis
Fossil body mass estimation is a well established practice within the field of physical anthropology. Previous studies have relied upon traditional allometric approaches, in which the relationship between one/several skeletal dimensions and body mass in a range of modern taxa is used in a predictive capacity. The lack of relatively complete skeletons has thus far limited the potential application of alternative mass estimation techniques, such as volumetric reconstruction, to fossil hominins. Yet across vertebrate paleontology more broadly, novel volumetric approaches are resulting in predicted values for fossil body mass very different to those estimated by traditional allometry. Here we present a new digital reconstruction of Australopithecus afarensis (A.L. 288-1; ‘Lucy’) and a convex hull-based volumetric estimate of body mass. The technique relies upon identifying a predictable relationship between the ‘shrink-wrapped’ volume of the skeleton and known body mass in a range of modern taxa, and subsequent application to an articulated model of the fossil taxa of interest. Our calibration dataset comprises whole body computed tomography (CT) scans of 15 species of modern primate. The resulting predictive model is characterized by a high correlation coefficient (r2 = 0.988) and a percentage standard error of 20%, and performs well when applied to modern individuals of known body mass. Application of the convex hull technique to A. afarensis results in a relatively low body mass estimate of 20.4 kg (95% prediction interval 13.5–30.9 kg). A sensitivity analysis on the articulation of the chest region highlights the sensitivity of our approach to the reconstruction of the trunk, and the incomplete nature of the preserved ribcage may explain the low values for predicted body mass here. We suggest that the heaviest of previous estimates would require the thorax to be expanded to an unlikely extent, yet this can only be properly tested when more complete fossils are available
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