wjority vote model on multiplex networks with two independently generted lyers in the form of sleEfree networks is investigted y mens of wonte grlo simultions nd heterogeneous menE(eld pproximtionF sn version of the model under study eh gent with proility 1 − q @0 ≤ q ≤ 1/2A follows the opinions of the mjorities of her neighors within oth lyers if these opinions re identilY otherwiseD she mkes deision rndomlyF he model exhiits seondEorder ferromgneti trnsition s qD the prmeter mesuring the level of internl noiseD is deresedD with ritil exponents depending on the detils of the degree distriutions in the lyersF he ritil vlue qc of the prmeter q evluted in the heterogeneous menE(eld pproximtion shows quntittive greement with tht otined from numeril simultions for rod rnge of prmeters hrterizing the degree distriutions of the lyersF hysX IHFIPTWQGehysoleFIQQFIRQQ egGtopisX opinion formtionD mjority vote modelD multiplex networks

In this paper, we provide the exact expression for the coefficients in the low-temperature series expansion of the partition function of the two-dimensional Ising model on the infinite square lattice. This is equivalent to exact determination of the number of spin configurations at a given energy. With these coefficients, we show that the ferromagnetic–to–paramagnetic phase transition in the square lattice Ising model can be explained through equivalence between the model and the perfect gas of energy clusters model, in which the passage through the critical point is related to the complete change in the thermodynamic preferences on the size of clusters. The combinatorial approach reported in this article is very general and can be easily applied to other lattice models.

The growing popularity of bibliometric indexes (whose most famous example is thehindex by J. E. Hirsch [J. E. Hirsch,Proc. Natl. Acad. Sci. U.S.A.102, 16569–16572 (2005)]) is opposed by those claiming that one’s scientific impact cannot be reduced to a single number. Some even believe that our complex reality fails to submit to any quantitative description. We argue that neither of the two controversial extremes is true. By assuming that some citations are distributed according to the rich get richer rule (success breeds success, preferential attachment) while some others are assigned totally at random (all in all, a paper needs a bibliography), we have crafted a model that accurately summarizes citation records with merely three easily interpretable parameters: productivity, total impact, and how lucky an author has been so far.

No abstract

An observational error of heart rate variability (HRV) may arise from many factors, such as a limited sampling frequency, QRS complexes detection process, preprocessing procedures and others. In our study, we focused on the first two origins of measurement error. We introduced a model of observational error and suggested universal descriptors for the assessment of its resultant magnitude in terms of time, frequency as well as nonlinear parameters. For this purpose, we applied Monte Carlo simulations which showed that the most sensitive to observational error are: pNN50 (the proportion of pairs of successive RR intervals that differ by more than 50 ms) and markers obtained from frequency analysis. On the other hand, the most resistant are other time domain parameters as well as the short and long-term slopes of Detrended Fluctuation Analysis (DFA). We postulate that the observational error should be considered in population studies, when different recorders are used in the research centres. Additionally, in the case of patients with similar etiology of disease but with different heart rhythms abnormalities the scatter of HRV parameters will also be observed due to the subject's the time series variability.