10,211 research outputs found
A Unified Trading Model Based on Robust Optimization for Day-Ahead and Real-Time Markets with Wind Power Integration
In a conventional electricity market, trading is conducted based on power forecasts in the day-ahead market, while the power imbalance is regulated in the real-time market, which is a separate trading scheme. With large-scale wind power connected into the power grid, power forecast errors increase in the day-ahead market which lowers the economic efficiency of the separate trading scheme. This paper proposes a robust unified trading model that includes the forecasts of real-time prices and imbalance power into the day-ahead trading scheme. The model is developed based on robust optimization in view of the undefined probability distribution of clearing prices of the real-time market. For the model to be used efficiently, an improved quantum-behaved particle swarm algorithm (IQPSO) is presented in the paper based on an in-depth analysis of the limitations of the static character of quantum-behaved particle swarm algorithm (QPSO). Finally, the impacts of associated parameters on the separate trading and unified trading model are analyzed to verify the superiority of the proposed model and algorithm
Spontaneous stable rotation of flocking flexible active matter
In nature, active matter, such as worms or dogs, tend to spontaneously form a
stable rotational cluster when they flock to the same food source on an
unregulated and unconfined surface. {In this paper we present an -node
flexible active matter model to study the collective motion due to the flocking
of individual agents on a two-dimensional surface, and confirm that there
exists a spontaneous stable cluster rotation synchronizing with a chirality
produced by the alignment of their bodies under the impetus of the active
force.} A prefactor of 1.86 is obtained for the linear relationship between
normalized angular velocity and chirality. The angular velocity of such a
rotation is found to be dependent on the individual flexibility, the number of
nodes in each individual, and the magnitude of the active force. The
conclusions well explain the spontaneous stable rotation of clusters that
exists in many flexible active matter, like worms or {dogs}, when they flock to
the same single source
Hawking radiation of black holes in the Horava-Lifshitz gravity
We investigate the Hawking radiation of 3+1 and 4+1 dimensional black holes
in the Horava-Lifshitz gravity with fermion tunnelling. It turns out
that the Hawking temperatures are recovered and are in consistence with those
obtained by calculating surface gravity of the black holes. For the 3+1
dimensional black holes, the Hawking temperatures are related to the
fundamental parameters of Horava-Lifshitz gravity.Comment: V2: references added, typo corrected, 16page
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