13,644 research outputs found
Exploring the Dynamics of Building Supply: A Duration Model of the Development Cycle
A noticeable omission in the existing body of applied real estate research is the lack of empirical analysis of the commercial development process. We address this shortcoming by utilizing a large panel database of individual building projects that in principle allows us to follow individual projects through various stages of their development life cycle. We begin by examining the basic distributional and time series characteristics of the development cycle, and then examine how these results vary by stage of construction, property sector and geography. We then estimate unconditional transition probabilities and finally, present preliminary results from a formal, nonparametric duration model.
First results of systematic studies done with different types of Silicon Photomultipliers
The presented results are obtained during the first steps taken in order to
develop a setup and measurement procedures which allow to compare properties of
diverse kinds of silicon photomultipliers. The response to low-intensity light
was studied for silicon photomultipliers produced by CPTA (Russia), Hamamatsu
(Japan), ITC-irst (Italy) and SensL (Ireland).Comment: 3 pages, 3 figures, proceedings of the Internationa Linear Collider
Workshop LCWS2007, Hamburg, German
The population of hot subdwarf stars studied with Gaia II. The Gaia DR2 catalogue of hot subluminous stars
Based on data from the ESA Gaia Data Release 2 (DR2) and several
ground-based, multi-band photometry surveys we compiled an all-sky catalogue of
hot subluminous star candidates selected in Gaia DR2 by means of
colour, absolute magnitude and reduced proper motion cuts. We expect the
majority of the candidates to be hot subdwarf stars of spectral type B and O,
followed by blue horizontal branch stars of late B-type (HBB), hot post-AGB
stars, and central stars of planetary nebulae. The contamination by cooler
stars should be about . The catalogue is magnitude limited to Gaia
and covers the whole sky. Except within the Galactic plane
and LMC/SMC regions, we expect the catalogue to be almost complete up to about
. The main purpose of this catalogue is to serve as input
target list for the large-scale photometric and spectroscopic surveys which are
ongoing or scheduled to start in the coming years. In the long run, securing a
statistically significant sample of spectroscopically confirmed hot subluminous
stars is key to advance towards a more detailed understanding of the latest
stages of stellar evolution for single and binary stars.Comment: 13 pages, A&A, accepte
Coherent Diffraction Imaging of Single 95nm Nanowires
Photonic or electronic confinement effects in nanostructures become
significant when one of their dimension is in the 5-300 nm range. Improving
their development requires the ability to study their structure - shape, strain
field, interdiffusion maps - using novel techniques. We have used coherent
diffraction imaging to record the 3-dimensionnal scattered intensity of single
silicon nanowires with a lateral size smaller than 100 nm. We show that this
intensity can be used to recover the hexagonal shape of the nanowire with a
28nm resolution. The article also discusses limits of the method in terms of
radiation damage.Comment: 5 pages, 5 figure
Pervasive Displays Research: What's Next?
Reports on the 7th ACM International Symposium on Pervasive Displays that took place from June 6-8 in Munich, Germany
Analysis of cool DO-type white dwarfs from the Sloan Digital Sky Survey Data Release 10
We report on the identification of 22 new cool DO-type white dwarfs (WD)
detected in Data Release 10 (DR10) of the Sloan Digital Sky Survey (SDSS).
Among them, we found one more member of the so-called hot-wind DO WDs, which
show ultrahigh excitation absorption lines. Our non-LTE model atmosphere
analyses of these objects and two not previously analyzed hot-wind DO WDs,
revealed effective temperatures and gravities in the ranges Teff=45-80kK and
log g= 7.50-8.75. In eight of the spectra we found traces of C (0.001-0.01, by
mass). Two of these are the coolest DO WDs ever discovered that still show a
considerable amount of C in their atmospheres. This is in strong contradiction
with diffusion calculations, and probably, similar to what is proposed for DB
WDs, a weak mass-loss is present in DO WDs. One object is the most massive DO
WD discovered so far with a mass of 1.07 M_sun if it is an ONe-WD or 1.09 M_sun
if it is a CO-WD. We furthermore present the mass distribution of all known hot
non-DA (pre-) WDs and derive the hot DA to non-DA ratio for the SDSS DR7
spectroscopic sample. The mass distribution of DO WDs beyond the wind limit
strongly deviates from the mass distribution of the objects before the wind
limit. We address this phenomenon by applying different evolutionary input
channels. We argue that the DO WD channel may be fed by about 13% by
post-extreme-horizontal branch stars and that PG1159 stars and O(He) stars may
contribute in a similar extent to the non-DA WD channel.Comment: 13 pages, accepted for publication in A&
Modular Middleware for Gestural Data and Devices Management
In the last few years, the use of gestural data has become a key enabler for human-computer interaction (HCI) applications. The growing diffusion of low-cost acquisition devices has thus led to the development of a class of middleware aimed at ensuring a fast and easy integration of such devices within the actual HCI applications. The purpose of this paper is to present a modular middleware for gestural data and devices management. First, we describe a brief review of the state of the art of similar middleware. Then, we discuss the proposed architecture and the motivation behind its design choices. Finally, we present a use case aimed at demonstrating the potential uses as well as the limitations of our middleware
Precision Measurement of the n-3He Incoherent Scattering Length Using Neutron Interferometry
We report the first measurement of the low-energy neutron-He incoherent
scattering length using neutron interferometry: fm. This is in good agreement with a
recent calculation using the AV18+3N potential. The neutron-He scattering
lengths are important for testing and developing nuclear potential models that
include three nucleon forces, effective field theories for few-body nuclear
systems, and neutron scattering measurements of quantum excitations in liquid
helium. This work demonstrates the first use of a polarized nuclear target in a
neutron interferometer.Comment: 4 figure
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