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Cities on and off the map: A bibliometric assessment of urban globalisation research
Growing out of writings on Global (North) cities, urban globalisation research (UGR) has expanded its canon to engage with an increasing diversity of cities and locations. Yet, this broadening has been uneven and controversial in its theoretical horizons and empirical universe. Focusing on the latter, this paper combines bibliometric, demographic, economic and georeferenced data to assess how UGR maps onto internationally documented cities ( n : 1692). Our study analyses city-themed publications by city location, demographic size and home-country income (2000–2014). Drawing on social science publications indexed in English (Scopus database), our results provide grounds for cautious optimism: recent publications offer broader, though still uneven coverage. The moving spatial average of publication counts also implies that the topical centre of published research gravity is shifting away from Euro-America. Yet, UGR lags in its coverage of the urban geographical universe, failing to keep pace with the economic/demographic trends that are resulting in southward/eastward shifts in worldwide urbanisation. Furthermore, while smaller cities and those in lower-income countries are still sidelined, cities in upper-middle income countries exhibit the largest gaps between observed and expected publication values. In our conclusion, we contend that urban bibliometrics could be further mobilised to identify publication foci and lacunae. Applied to cities on and off the map and a broader universe of urban knowledges, bibliometrics could help move contentious debates forward, identifying newer paradigms that may be engaging the world of cities beyond the globalisation umbrella and charting out multiple and complex topical relations across variegated worlds of urbanism
Calibration of the Particle Density in Cellular-Automaton Models for Traffic Flow
We introduce density dependence of the cell size in cellular-automaton models
for traffic flow, which allows a more precise correspondence between real-world
phenomena and what observed in simulation. Also, we give an explicit
calibration of the particle density particularly for the asymmetric simple
exclusion process with some update rules. We thus find that the present method
is valid in that it reproduces a realistic flow-density diagram.Comment: 2 pages, 2 figure
Exact solution and asymptotic behaviour of the asymmetric simple exclusion process on a ring
In this paper, we study an exact solution of the asymmetric simple exclusion
process on a periodic lattice of finite sites with two typical updates, i.e.,
random and parallel. Then, we find that the explicit formulas for the partition
function and the average velocity are expressed by the Gauss hypergeometric
function. In order to obtain these results, we effectively exploit the
recursion formula for the partition function for the zero-range process. The
zero-range process corresponds to the asymmetric simple exclusion process if
one chooses the relevant hop rates of particles, and the recursion gives the
partition function, in principle, for any finite system size. Moreover, we
reveal the asymptotic behaviour of the average velocity in the thermodynamic
limit, expanding the formula as a series in system size.Comment: 10 page
Depth profile photoemission study of thermally diffused Mn/GaAs (001) interfaces
We have performed a depth profile study of thermally diffused Mn/GaAs (001)
interfaces using photoemission spectroscopy combined with Ar-ion
sputtering. We found that Mn ion was thermally diffused into the deep region of
the GaAs substrate and completely reacted with GaAs. In the deep region, the Mn
2 core-level and Mn 3 valence-band spectra of the Mn/GaAs (001) sample
heated to 600 C were similar to those of GaMnAs,
zinc-blende-type MnAs dots, and/or interstitial Mn in tetrahedrally coordinated
by As atoms, suggesting that the Mn 3 states were essentially localized but
were hybridized with the electronic states of the host GaAs. Ferromagnetism was
observed in the dilute Mn phase.Comment: 5 pages, 4 figure
Measuring errors in single qubit rotations by pulsed electron paramagnetic resonance
The ability to measure and reduce systematic errors in single-qubit logic
gates is crucial when evaluating quantum computing implementations. We describe
pulsed electron paramagnetic resonance (EPR) sequences that can be used to
measure precisely even small systematic errors in rotations of
electron-spin-based qubits. Using these sequences we obtain values for errors
in rotation angle and axis for single-qubit rotations using a commercial EPR
spectrometer. We conclude that errors in qubit operations by pulsed EPR are not
limiting factors in the implementation of electron-spin based quantum
computers
Band Calculations for Ce Compounds with AuCu-type Crystal Structure on the basis of Dynamical Mean Field Theory I. CePd and CeRh
Band calculations for Ce compounds with the AuCu-type crystal structure
were carried out on the basis of dynamical mean field theory (DMFT). The
auxiliary impurity problem was solved by a method named NCAvc
(noncrossing approximation including the state as a vertex correction).
The calculations take into account the crystal-field splitting, the spin-orbit
interaction, and the correct exchange process of the virtual excitation. These are necessary features in the
quantitative band theory for Ce compounds and in the calculation of their
excitation spectra. The results of applying the calculation to CePd and
CeRh are presented as the first in a series of papers. The experimental
results of the photoemission spectrum (PES), the inverse PES, the
angle-resolved PES, and the magnetic excitation spectra were reasonably
reproduced by the first-principles DMFT band calculation. At low temperatures,
the Fermi surface (FS) structure of CePd is similar to that of the band
obtained by the local density approximation. It gradually changes into a form
that is similar to the FS of LaPd as the temperature increases, since the
band shifts to the high-energy side and the lifetime broadening becomes
large.}Comment: 12 pasges, 13 figure
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