10,853 research outputs found
Recommended from our members
Using data from connected thermostats to track large power outages in the United States
The detection of power outages is an essential activity for electric utilities. A large, national dataset of Internet-connected thermostats was used to explore and illustrate the ability of Internet-connected devices to geospatially track outages caused by hurricanes and other major weather events. The method was applied to nine major outage events, including hurricanes and windstorms. In one event, Hurricane Irma, a network of about 1000 thermostats provided quantitatively similar results to detailed utility data with respect to the number of homes without power and identification of the most severely affected regions. The method generated regionally uniform outage data that would give emergency authorities additional visibility into the scope and magnitude of outages. The network of thermostat-sensors also made it possible to calculate a higher resolution version of outage duration (or SAIDI) at a level of customer-level visibility that was not previously available
Moduli Space of Topological 2-form Gravity
We propose a topological version of four-dimensional (Euclidean) Einstein
gravity, in which anti-self-dual 2-forms and an SU(2) connection are used as
fundamental fields. The theory describes the moduli space of conformally
self-dual Einstein manifolds. In the presence of a cosmological constant, we
evaluate the index of the elliptic complex associated with the moduli space.Comment: 10pages, Latex (minor changes
Integrable Top Equations associated with Projective Geometry over Z_2
We give a series of integrable top equations associated with the projective
geometry over Z_2 as a (2^n-1)-dimensional generalisation of the 3D Euler top
equations. The general solution of the (2^n-1)D top is shown to be given by an
integration over a Riemann surface with genus (2^{n-1}-1)^2.Comment: 8 pages, Late
Integrable field theories derived from 4D self-dual gravity
We reformulate the self-dual Einstein equation as a trio of differential form equations for simple two-forms. Using them, we can quickly show the equivalence of the theory and 2D sigma models valued in infinite-dimensional group, which was shown by Park and Husain earlier. We also derive other field theories including the 2D Higgs bundle equation. This formulation elucidates the relation among those field theories
Visibility and aerosol measurement by diode-laser random-modulation CW lidar
Examples of diode laser (DL) random-modulation continuous wave (RM-CW) lidar measurements are reported. The ability of the measurement of the visibility, vertical aerosol profile, and the cloud ceiling height is demonstrated. Although the data shown here were all measured at night time, the daytime measurement is, of course, possible. For that purpose, accurate control of the laser frequency to the center frequency of a narrow band filter is required. Now a new system with a frequency control is under construction
Hybrid ECAL: Optimization and Related Developments
Hybrid ECAL is a cost-conscious option of electromagnetic calorimeter (ECAL)
for particle flow calorimetry to be used in a detector of International Linear
Collider (ILC). It is a combination of silicon-tungsten ECAL, which realizes
high granularity and robust measurement of electromagnetic shower, and
scintillator-tungsten ECAL, which gives affordable cost with similar
performance to silicon. Optimization and a data acquisition trial in a test
bench for the hybrid ECAL are described in this article.Comment: 7 pages, 4 figures, Talk presented at the International Workshop on
Future Linear Colliders (LCWS14), Belgrade, Serbia, 6-10 October 201
Field Effect Transistor Based on KTaO3 Perovskite
An n-channel accumulation-type field effect transistor (FET) has been
fabricated utilizing a KTaO3 single crystal as an active element and a
sputtered amorphous Al2O3 film as a gate insulator. The device demonstrated an
ON/OFF ratio of 10^4 and a field effect mobility of 0.4cm^2/Vs at room
temperature, both of which are much better than those of the SrTiO3 FETs
reported previously. The field effect mobility was almost temperature
independent down to 200K. Our results indicate that the Al2O3 / KTaO3 interface
is worthy of further investigations as an alternative system of future oxide
electronics.Comment: 3 pages, 3 Postscript figures, submitted to Appl.Phys.Let
Ground-state electric quadrupole moment of 31Al
Ground-state electric quadrupole moment of 31Al (I =5/2+, T_1/2 = 644(25) ms)
has been measured by means of the beta-NMR spectroscopy using a spin-polarized
31Al beam produced in the projectile fragmentation reaction. The obtained Q
moment, |Q_exp(31Al)| = 112(32)emb, are in agreement with conventional shell
model calculations within the sd valence space. Previous result on the magnetic
moment also supports the validity of the sd model in this isotope, and thus it
is concluded that 31Al is located outside of the island of inversion.Comment: 5 page
- …