36,442 research outputs found
Joint power and admission control via p norm minimization deflation
In an interference network, joint power and admission control aims to support
a maximum number of links at their specified signal to interference plus noise
ratio (SINR) targets while using a minimum total transmission power. In our
previous work, we formulated the joint control problem as a sparse
-minimization problem and relaxed it to a -minimization
problem. In this work, we propose to approximate the -optimization
problem to a p norm minimization problem where , since intuitively p
norm will approximate 0 norm better than 1 norm. We first show that the
-minimization problem is strongly NP-hard and then derive a
reformulation of it such that the well developed interior-point algorithms can
be applied to solve it. The solution to the -minimization problem can
efficiently guide the link's removals (deflation). Numerical simulations show
the proposed heuristic outperforms the existing algorithms.Comment: 2013 IEEE International Conference on Acoustics, Speech, and Signal
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Topological phase in topological Kondo insulator: topological insulator, Haldane-like phase and Kondo breakdown
We have simulated a half-filled -wave periodic Anderson model with
numerically exact projector quantum Monte Carlo technique, and the system is
indeed located in the Haldane-like state as detected in previous works on the
-wave Kondo lattice model, though the soluble non-interacting limit
corresponds to the conventional topological insulator. The
site-resolved magnetization in an open boundary system and strange correlator
for the periodic boundary have been used to identify the mentioned topological
states. Interestingly, the edge magnetization in the Haldane-like state is not
saturated to unit magnetic moment due to the intrinsic charge fluctuation in
our periodic Anderson-like model, which is beyond the description of the Kondo
lattice-like model in existing literature. The finding here underlies the
correlation driven topological state in this prototypical interacting
topological state of matter and naive use of non-interacting picture should be
taken care. Moreover, no trace of the surface Kondo breakdown at zero
temperature is observed and it is suspected that frustration-like interaction
may be crucial in inducing such radical destruction of Kondo screening. The
findings here may be relevant to our understanding of interacting topological
materials like topological Kondo insulator candidate SmB.Comment: 11 pages, 9 figures, accepted by EPJ
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