32,088 research outputs found
A Frequency-Reconfigurable Monopole Antenna with Switchable Stubbed Ground Structure
A frequency-reconfigurable coplanar-waveguide (CPW) fed monopole antenna using switchable stubbed ground structure is presented. Four PIN diodes are employed in the stubs stretching from the ground to make the antenna reconfigurable in three operating modes: a single-band mode (2.4-2.9 GHz), a dual-band mode (2.4-2.9 GHz/5.09-5.47 GHz) and a triple-band mode (3.7-4.26 GHz/5.3-6.3 GHz/8.0-8.8 GHz). The monopole antenna is resonating at 2.4 GHz, while the stubs produce other operating frequency bands covering a number of wireless communication systems, including WLAN, WiMAX, C-band, and ITU. Furthermore, an optimized biasing network has been integrated into this antenna, which has little influence on the performance of the antenna. This paper presents, compares and discusses the simulated and measured results
Surface electrical properties experiment. Part 2: Theory of radio-frequency interferometry in geophysical subsurface probing
The radiation fields due to a horizontal electric dipole laid on the surface of a stratified medium were calculated using a geometrical optics approximation, a modal approach, and direct numerical integration. The solutions were obtained from the reflection coefficient formulation and written in integral forms. The calculated interference patterns are compared in terms of the usefulness of the methods used to obtain them. Scattering effects are also discussed and all numerical results for anisotropic and isotropic cases are presented
In search of permanent homes: Singapore's house churches and the politics of space
10.1080/00420980220151664Urban Studies3991573-158
Religious processions: Urban politics and poetics
Temenos412225-24
Ideological hegemony and the political symbolism of religious buildings in Singapore
Environment & Planning D: Society & Space11123-4
Cultural policy in Singapore: Negotiating economic and socio-cultural agendas
10.1016/S0016-7185(00)00006-3Geoforum314409-42
Efficient implementation of a van der Waals density functional: Application to double-wall carbon nanotubes
We present an efficient implementation of the van der Waals density
functional of Dion et al [Phys. Rev. Lett. 92, 246401 (2004)], which expresses
the nonlocal correlation energy as a double spacial integral. We factorize the
integration kernel and use fast Fourier transforms to evaluate the
selfconsistent potential, total energy, and atomic forces, in N log(N)
operations. The resulting overhead in total computational cost, over semilocal
functionals, is very moderate for medium and large systems. We apply the method
to calculate the binding energies and the barriers for relative translation and
rotation in double-wall carbon nanotubes.Comment: 4 pages, 1 figure, 1 tabl
Rejoinder: Quantifying the Fraction of Missing Information for Hypothesis Testing in Statistical and Genetic Studies
Rejoinder to "Quantifying the Fraction of Missing Information for Hypothesis
Testing in Statistical and Genetic Studies" [arXiv:1102.2774]Comment: Published in at http://dx.doi.org/10.1214/08-STS244REJ the
Statistical Science (http://www.imstat.org/sts/) by the Institute of
Mathematical Statistics (http://www.imstat.org
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