4,513 research outputs found
Children’s participatory design for sustainable development and community planning
The urban developments have been carried out by only professionals for a long time because of efficiency and safety. However, most residents are ordinary people. Therefore, it is necessary to change the awareness of sustainable living environments, not only on the construction side but also the residents. In recent years, the number of cases of residents’ participation in planning, maintaining, and repairing increased. However, sometimes youths and children, who might spend a lifetime longer than adults in a city after the developments have been done, are not included in this “Residents”. Concerning youth and children’s participation, CFC (child friendly city) is one of the good practices for sustainable development. It was launched by UNICEF (United Nations International Children’s Emergency Fund) and UN-Habitat in the Habitat II in 1996. City governments, especially in European countries, started to view CFC as their key concept for preservation and/or sustainable development. CFC means not only being “Children” friendly but also “All people” friendly. Various effects have been reported since the Historic Cities/districts included CFC in their city planning as a common concept, especially in education, community re-development, and operation and maintenance by the community. It is expected that better city planning in preservation and sustainable development can be achieved by adding CFC concept. In this research, an ideal way of city planning involving resident participation and the possibility in the future are analyzed based on case studies. Then a strategy of sustainable development and community planning involving youth and children’s participation is proposed.published_or_final_versio
Study of systematics effects on the Cross Power Spectrum of 21 cm Line and Cosmic Microwave Background using Murchison Widefield Array Data
Observation of the 21cm line signal from neutral hydrogen during the Epoch of
Reionization is challenging due to extremely bright Galactic and extragalactic
foregrounds and complicated instrumental calibration. A reasonable approach for
mitigating these problems is the cross correlation with other observables. In
this work, we present the first results of the cross power spectrum (CPS)
between radio images observed by the Murchison Widefield Array and the cosmic
microwave background (CMB), measured by the Planck experiment. We study the
systematics due to the ionospheric activity, the dependence of CPS on group of
pointings, and frequency. The resulting CPS is consistent with zero because the
error is dominated by the foregrounds in the 21cm observation. Additionally,
the variance of the signal indicates the presence of unexpected systematics
error at small scales. Furthermore, we reduce the error by one order of
magnitude with application of a foreground removal using a polynomial fitting
method. Based on the results, we find that the detection of the 21cm-CMB CPS
with the MWA Phase I requires more than 99.95% of the foreground signal
removed, 2000 hours of deep observation and 50% of the sky fraction coverage.Comment: 15 pages, 16 figures, accepted to MNRA
Evidence of non-thermal X-ray emission from radio lobes of Cygnus A
Using deep Chandra ACIS observation data for Cygnus A, we report evidence of
non-thermal X-ray emission from radio lobes surrounded by a rich intra-cluster
medium (ICM). The diffuse X-ray emission, which are associated with the eastern
and western radio lobes, were observed in a 0.7--7 keV Chandra$ ACIS image. The
lobe spectra are reproduced with not only a single-temperature Mekal model,
such as that of the surrounding ICM component, but also an additional power-law
(PL) model. The X-ray flux densities of PL components for the eastern and
western lobes at 1 keV are derived as 77.7^{+28.9}_{-31.9} nJy and
52.4^{+42.9}_{-42.4} nJy, respectively, and the photon indices are
1.69^{+0.07}_{-0.13} and 1.84^{+2.90}_{-0.12}, respectively. The non-thermal
component is considered to be produced via the inverse Compton (IC) process, as
is often seen in the X-ray emission from radio lobes. From a re-analysis of
radio observation data, the multiwavelength spectra strongly suggest that the
seed photon source of the IC X-rays includes both cosmic microwave background
radiation and synchrotron radiation from the lobes. The derived parameters
indicate significant dominance of the electron energy density over the magnetic
field energy density in the Cygnus A lobes under the rich ICM environment.Comment: 8 pages, 5 figures, accepted for publication in Ap
Interaction of massless Dirac field with a Poincar\'e gauge field
In this paper we consider a model of Poincar\'e gauge theory (PGT) in which a
translational gauge field and a Lorentz gauge field are actually identified
with the Einstein's gravitational field and a pair of ``Yang-Mills'' field and
its partner, respectively.In this model we re-derive some special solutions and
take up one of them. The solution represents a ``Yang-Mills'' field without its
partner field and the Reissner-Nordstr\"om type spacetime, which are generated
by a PGT-gauge charge and its mass.It is main purpose of this paper to
investigate the interaction of massless Dirac fields with those fields. As a
result, we find an interesting fact that the left-handed massless Dirac fields
behave in the different manner from the right-handed ones. This can be
explained as to be caused by the direct interaction of Dirac fields with the
``Yang-Mills'' field. Accordingly, the phenomenon can not happen in the
behavior of the neutrino waves in ordinary Reissner-Nordstr\"om geometry. The
difference between left- and right-handed effects is calculated quantitatively,
considering the scattering problems of the massless Dirac fields by our
Reissner-Nordstr\"om type black-hole.Comment: 10pages, RevTeX3.
Exchange effects in elastic collisions of spin-polarized electrons with open-shell molecules with symmetry
The spin-exchange effect in spin-polarized electron collisions with
unpolarized open-shell molecules, O, B, S and Si, has been
studied by the R-matrix method with the fixed-bond approximation. All of these
molecules have symmetry in their ground states. Usual
integrated cross sections with unpolarized electrons has also been studied. We
used the complete active space self consistent field orbitals and put more than
10 target electronic states in the R-matrix models. In electron O elastic
collisions, calculated polarization fractions agree well with the experimental
results, especially around the resonance. In e-B, S
and Si elastic collisions, larger spin-exchange effect is observed compared
to the e-O elastic collisions. In all four cases, spin-exchange effect
becomes prominent near resonances. This association of resonance and magnitude
of the spin-exchange effect was studied by explicitly removing the resonance
configurations from the R-matrix calculations. In general, spin-exchange effect
is larger in e-B collisions than in e-S and Si collisions, and is
smallest in e-O collisions.Comment: Phys. Rev. A, in pres
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