59,394 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
Strangeness production in heavy ion collisions at SPS and RHIC within two-source statistical model
The experimental data on hadron yields and ratios in central Pb+Pb and Au+Au
collisions at SPS and RHIC energies, respectively, are analysed within a
two-source statistical model of an ideal hadron gas. These two sources
represent the expanding system of colliding heavy ions, where the hot central
fireball is embedded in a larger but cooler fireball. The volume of the central
source increases with rising bombarding energy. Results of the two-source model
fit to RHIC experimental data at midrapidity coincide with the results of the
one-source thermal model fit, indicating the formation of an extended fireball,
which is three times larger than the corresponding core at SPS.Comment: Talk at "Strange Quarks in Matter" Conference (Strangeness'2001),
September 2001, Frankfurt a.M., German
Using particle shape to induce tilted and bistable liquid crystal anchoring
We use Monte Carlo simulations of hard Gaussian overlap (HGO) particles symmetrically confined in slab geometry to investigate the role of particle-substrate interactions on liquid crystalline
anchoring. Despite the restriction here to purely steric interactions and smooth substrates, a range of behaviours are captured, including tilted anchoring and homeotropic-planar bistability. These macroscopic behaviours are all achieved through appropriate tuning of the microscopics of the HGO-substrate interaction, based upon non-additive descriptions for the HGO-substrate shape parameter.</p
Annihilation Type Radiative Decays of Meson in Perturbative QCD Approach
With the perturbative QCD approach based on factorization, we study the
pure annihilation type radiative decays and . We find that the branching ratio of is
, which is too small to be measured
in the current factories of BaBar and Belle. The branching ratio of is , which is just
at the corner of being observable in the factories. A larger branching
ratio is also predicted.
These decay modes will help us testing the standard model and searching for new
physics signals.Comment: 4 pages, revtex, with 1 eps figur
Gamma-ray bursts: postburst evolution of fireballs
The postburst evolution of fireballs that produce -ray bursts is
studied, assuming the expansion of fireballs to be adiabatic and relativistic.
Numerical results as well as an approximate analytic solution for the evolution
are presented. Due to adoption of a new relation among , and
(see the text), our results differ markedly from the previous studies.
Synchrotron radiation from the shocked interstellar medium is attentively
calculated, using a convenient set of equations. The observed X-ray flux of GRB
afterglows can be reproduced easily. Although the optical afterglows seem much
more complicated, our results can still present a rather satisfactory approach
to observations. It is also found that the expansion will no longer be highly
relativistic about 4 days after the main GRB. We thus suggest that the
marginally relativistic phase of the expansion should be investigated so as to
check the afterglows observed a week or more later.Comment: 17 pages, 4 figures, MNRAS in pres
Is GRO J1744-28 a Strange Star?
The unusal hard x-ray burster GRO J1744-28 recently discovered by the Compton
Gamma-ray Observatory (GRO) can be modeled as a strange star with a dipolar
magnetic field Gauss. When the accreted mass of the star exceeds
some critical mass, its crust may break, resulting in conversion of the
accreted matter into strange matter and release of energy. Subsequently, a
fireball may form and expand relativistically outward. The expanding fireball
may interact with the surrounding interstellar medium, causing its kinetic
energy to be radiated in shock waves, producing a burst of x-ray radiation. The
burst energy, duration, interval and spectrum derived from such a model are
consistent with the observations of GRO J1744-28.Comment: Latex, has been published in SCIENCE, Vol. 280, 40
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