47 research outputs found
Relative Rota-Baxter operators of nonzero weights on -Lie algebras and 3-post-Lie algebras
In this paper, first we introduce the notion of a relative Rota-Baxter
operator of nonzero weights on a -Lie algebra with respect to an action on
another 3-Lie algebra, which can be characterized by graphs of the semidirect
product 3-Lie algebra constructed from the action. %We show that a relative
Rota-Baxter operator of weight induces a new -Lie algebra
structure, which is called the descendent 3-Lie algebra. Then we introduce a
new algebraic structure, which is called a -post-Lie algebra. A 3-post-Lie
algebra consists of a 3-Lie algebra structure and a ternary operation such that
some compatibility conditions are satisfied. We show that a relative
Rota-Baxter operator of nonzero weights induces a -post-Lie algebra
naturally. Thus -post-Lie algebras can be viewed as the underlying algebraic
structures of relative Rota-Baxter operators of nonzero weights on -Lie
algebras. Moreover, a -post-Lie algebra also gives rise to a new 3-Lie
algebra, which is called the subadjacent 3-Lie algebra, and an action on the
original 3-Lie algebra. Next we construct an -algebra from an action
of 3-Lie algebras whose Maurer-Cartan elements are relative Rota-Baxter
operators of nonzero weights. Consequently, we obtain the twisted
-algebra that controls deformations of a given relative Rota-Baxter
operator of nonzero weights on 3-Lie algebras. Finally, we construct a
cohomology theory for a relative Rota-Baxter operator of nonzero weights on
-Lie algebras and use the second cohomology group to classify infinitesimal
deformations.Comment: 22 pages. arXiv admin note: text overlap with arXiv:2107.13950,
arXiv:2108.0262
Two-Stage Submodular Optimization of Dynamic Thermal Rating for Risk Mitigation Considering Placement and Operation Schedule
Cascading failure causes a major risk to society currently. To effectively
mitigate the risk, dynamic thermal rating (DTR) technique can be applied as a
cost-effective strategy to exploit potential transmission capability. From the
perspectives of service life and Braess paradox, it is important and
challenging to jointly optimize the DTR placement and operation schedule for
changing system state, which is a two-stage combinatorial problem with only
discrete variables, suffering from no approximation guarantee and dimension
curse only based on traditional models. Thus, the present work proposes a novel
two-stage submodular optimization (TSSO) of DTR for risk mitigation considering
placement and operation schedule. Specifically, it optimizes DTR placement with
proper redundancy in first stage, and then determines the corresponding DTR
operation for each system state in second stage. Under the condition of the
Markov and submodular features in sub-function of risk mitigation, the
submodularity of total objective function of TSSO can be proven for the first
time. Based on this, a state-of-the-art efficient solving algorithm is
developed that can provide a better approximation guarantee than previous
studies by coordinating the separate curvature and error form. The performance
of the proposed algorithms is verified by case results
Dynamic Game-based Maintenance Scheduling of Integrated Electric and Natural Gas Grids with a Bilevel Approach
This paper proposes a dynamic game-based maintenance scheduling mechanism for
the asset owners of the natural gas grid and the power grid by using a bilevel
approach. In the upper level, the asset owners of the natural gas grid and the
power grid schedule maintenance to maximize their own revenues. This level is
modeled as a dynamic game problem, which is solved by the backward induction
algorithm. In the lower level, the independent system operator (ISO) dispatches
the system to minimize the loss of power load and natural gas load in
consideration of the system operating conditions under maintenance plans from
the asset owners in the upper level. This is modeled as a mixed integer linear
programming problem. For the model of the natural gas grid, a piecewise linear
approximation associated with the big-M approach is used to transform the
original nonlinear model into the mixed integer linear model. Numerical tests
on a 6-bus system with a 4-node gas grid show the effectiveness of the proposed
model.Comment: accepted by IEEE Transactions on Power System