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Two novel nonlinear companding schemes with iterative receiver to reduce PAPR in multi-carrier modulation systems
Companding transform is an efficient and simple method to reduce the Peak-to-Average Power Ratio (PAPR) for Multi-Carrier Modulation (MCM) systems. But if the MCM signal is only simply operated by inverse companding transform at the receiver, the resultant spectrum may exhibit severe in-band and out-of-band radiation of the distortion components, and considerable peak regrowth by excessive channel noises etc. In order to prevent these problems from occurring, in this paper, two novel nonlinear companding schemes with a iterative receiver are proposed to reduce the PAPR. By transforming the amplitude or power of the original MCM signals into uniform distributed signals, the novel schemes can effectively reduce PAPR for different modulation formats and sub-carrier sizes. Despite moderate complexity increasing at the receiver, but it is especially suitable to be combined with iterative channel estimation. Computer simulation results show that the proposed schemes can offer good system performances without any bandwidth expansion
From the Quantum Link Model on the Honeycomb Lattice to the Quantum Dimer Model on the Kagom\'e Lattice: Phase Transition and Fractionalized Flux Strings
We consider the -d quantum link model on the honeycomb lattice
and show that it is equivalent to a quantum dimer model on the Kagom\'e
lattice. The model has crystalline confined phases with spontaneously broken
translation invariance associated with pinwheel order, which is investigated
with either a Metropolis or an efficient cluster algorithm. External
half-integer non-Abelian charges (which transform non-trivially under the
center of the gauge group) are confined to each other
by fractionalized strings with a delocalized flux. The strands
of the fractionalized flux strings are domain walls that separate distinct
pinwheel phases. A second-order phase transition in the 3-d Ising universality
class separates two confining phases; one with correlated pinwheel
orientations, and the other with uncorrelated pinwheel orientations.Comment: 16 pages, 20 figures, 2 tables, two more relevant references and one
short paragraph are adde
Sputtered Gold as an Effective Schottky Gate for Strained Si/SiGe Nanostructures
Metallization of Schottky surface gates by sputtering Au on strained Si/SiGe
heterojunctions enables the depletion of the two dimensional electron gas
(2DEG) at a relatively small voltage while maintaining an extremely low level
of leakage current. A fabrication process has been developed to enable the
formation of sub-micron Au electrodes sputtered onto Si/SiGe without the need
of a wetting layer.Comment: 3 pages, 3 figure
From the Quantum Link Model on the Honeycomb Lattice to the Quantum Dimer Model on the Kagom\'e Lattice: Phase Transition and Fractionalized Flux Strings
We consider the -d quantum link model on the honeycomb lattice
and show that it is equivalent to a quantum dimer model on the Kagom\'e
lattice. The model has crystalline confined phases with spontaneously broken
translation invariance associated with pinwheel order, which is investigated
with either a Metropolis or an efficient cluster algorithm. External
half-integer non-Abelian charges (which transform non-trivially under the
center of the gauge group) are confined to each other
by fractionalized strings with a delocalized flux. The strands
of the fractionalized flux strings are domain walls that separate distinct
pinwheel phases. A second-order phase transition in the 3-d Ising universality
class separates two confining phases; one with correlated pinwheel
orientations, and the other with uncorrelated pinwheel orientations.Comment: 16 pages, 20 figures, 2 tables, two more relevant references and one
short paragraph are adde
Rank-ordered Multifractal Spectrum for Intermittent Fluctuations
We describe a new method that is both physically explicable and
quantitatively accurate in describing the multifractal characteristics of
intermittent events based on groupings of rank-ordered fluctuations. The
generic nature of such rank-ordered spectrum leads it to a natural connection
with the concept of one-parameter scaling for monofractals. We demonstrate this
technique using results obtained from a 2D MHD simulation. The calculated
spectrum suggests a crossover from the near Gaussian characteristics of small
amplitude fluctuations to the extreme intermittent state of large rare events.Comment: 4 pages, 5 figure
Construct, Merge, Solve and Adapt: Application to the repetition-free longest common subsequence problem
In this paper we present the application of a recently proposed, general, algorithm for combinatorial optimization to the repetition-free longest common subsequence problem. The applied algorithm, which is labelled Construct, Merge, Solve & Adapt, generates sub-instances based on merging the solution components found in randomly constructed solutions. These sub-instances are subsequently solved by means of an exact solver. Moreover, the considered sub-instances are dynamically changing due to adding new solution components at each iteration, and removing existing solution components on the basis of indicators about their usefulness. The results of applying this algorithm to the repetition-free longest common subsequence problem show that the algorithm generally outperforms competing approaches from the literature. Moreover, they show that the algorithm is competitive with CPLEX for small and medium size problem instances, whereas it outperforms CPLEX for larger problem instances.Peer ReviewedPostprint (author's final draft
Generalized Haldane Equation and Fluctuation Theorem in the Steady State Cycle Kinetics of Single Enzymes
Enyzme kinetics are cyclic. We study a Markov renewal process model of
single-enzyme turnover in nonequilibrium steady-state (NESS) with sustained
concentrations for substrates and products. We show that the forward and
backward cycle times have idential non-exponential distributions:
\QQ_+(t)=\QQ_-(t). This equation generalizes the Haldane relation in
reversible enzyme kinetics. In terms of the probabilities for the forward
() and backward () cycles, is shown to be the
chemical driving force of the NESS, . More interestingly, the moment
generating function of the stochastic number of substrate cycle ,
follows the fluctuation theorem in the form of
Kurchan-Lebowitz-Spohn-type symmetry. When $\lambda$ = $\Delta\mu/k_BT$, we
obtain the Jarzynski-Hatano-Sasa-type equality:
1 for all , where is the fluctuating chemical work
done for sustaining the NESS. This theory suggests possible methods to
experimentally determine the nonequilibrium driving force {\it in situ} from
turnover data via single-molecule enzymology.Comment: 4 pages, 3 figure
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