28,335 research outputs found
Power load forecasting
For the electric power factory, the power load forecasting problem, including load forecasting and consumption predicting, is crucial to work planning. According to the predicting time, it can be divided into long-term forecasting, mid-term forecasting, short-term forecasting and ultra-short-term forecasting. The long-term and mid-term forecasting are mainly used for macro control, and their forecasting time arrange are from one year to ten years and from one month to twelve months respectively. The short-term forecasting which prediction time is from one day to seven days is used in generators macroeconomic control, power exchange plan and some other areas. Predicting the situation in next 24 hours is named as the ultra-short-term forecasting which is used for failure prediction, emergency treatment and frequency control. In general, the forecast accuracy is different for different prediction time. The longer is the time, the lower accurate is the prediction.
As the unique power supplier in Huizhou (China), Huizhou Electric Power wants to know the solution to the problems: 1. Prediction of the total electrical consumption and the peak load of the city in 2006 based on the economy development and the feature of the city. 2. Monthly prediction of the consumption and peak load in 2006. 3. Daily prediction of the consumption and peak load from July 10th to 16th in 2006. 4. Prediction of the load every 15 minutes of July 10th. 5. Real-time forecasting which means to amend the existing load prediction for next 15 minute
Particle-Hole Symmetry Breaking and the 5/2 Fractional Quantum Hall Effect
We report on the study of the fractional quantum Hall effect at the filling
factor 5/2 using exact diagonalization method with torus geometry. The
particle-hole symmetry breaking effect is considered using an additional
three-body interaction. Both Pfaffian and anti-Pfaffian states can be the
ground state depending on the sign of the three-body interaction. The results
of the low-energy spectrum, the wave function overlap, and the particle-hole
parity evolution, have shown the clear evidence of a direct sharp transition
(possibly first-order) from the Pfaffian to the anti-Pfaffian state at the
Coulomb point. A quantum phase diagram is established, where one finds further
transitions from the Pfaffian or anti-Pfaffian state to the nearby compressible
phases induced by a change of the pseudopotential.Comment: 4 pages, 4 figure
Noise residuals for GW150914 using maximum likelihood and numerical relativity templates
We reexamine the results presented in a recent work by Nielsen et al. [1], in
which the properties of the noise residuals in the 40\,ms chirp domain of
GW150914 were investigated. This paper confirmed the presence of strong (i.e.,
about 0.80) correlations between residual noise in the Hanford and Livingston
detectors in the chirp domain as previously seen by us [2] when using a
numerical relativity template given in [3]. It was also shown in [1] that a
so-called maximum likelihood template can reduce these statistically
significant cross-correlations. Here, we demonstrate that the reduction of
correlation and statistical significance is due to (i) the use of a peculiar
template which is qualitatively different from the properties of GW150914
originally published by LIGO, (ii) a suspicious MCMC chain, (iii) uncertainties
in the matching of the maximum likelihood (ML) template to the data in the
Fourier domain, and (iv) a biased estimation of the significance that gives
counter-intuitive results. We show that rematching the maximum likelihood
template to the data in the 0.2\,s domain containing the GW150914 signal
restores these correlations at the level of of those found in [1]. With
necessary corrections, the probability given in [1] will decrease by more than
one order of magnitude. Since the ML template is itself problematic, results
associated with this template are illustrative rather than final.Comment: Minor correction
Broken-Symmetry States of Dirac Fermions in Graphene with A Partially Filled High Landau Level
We report on numerical study of the Dirac fermions in partially filled N=3
Landau level (LL) in graphene. At half-filling, the equal-time density-density
correlation function displays sharp peaks at nonzero wavevectors . Finite-size scaling shows that the peak value grows with electron
number and diverges in the thermodynamic limit, which suggests an instability
toward a charge density wave. A symmetry broken stripe phase is formed at large
system size limit, which is robust against purturbation from disorder
scattering. Such a quantum phase is experimentally observable through transport
measurements. Associated with the special wavefunctions of the Dirac LL, both
stripe and bubble phases become possible candidates for the ground state of the
Dirac fermions in graphene with lower filling factors in the N=3 LL.Comment: Contains are slightly changed. Journal reference and DOI are adde
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