The general quantum χ(2)-divergence has recently been introduced by Temme et al. [Temme K, Kastoryano M, Ruskai M, Wolf M, Verstrate F (2010) J Math Phys 51:122201] and applied to quantum channels (quantum Markov processes). The quantum χ(2)-divergence is not unique, as opposed to the classical χ(2)-divergence, but depends on the choice of quantum statistics. It was noticed that the elements in...

χ2 minimisation. The determination of parameters in fits to measured data is a standard task of data analysis. The standard method of least squares is often referred to as χ2 minimisation, which is a confusion in terminology; the minimum of the least squares sum follows often, but not always, the χ2 distribution. In “χ2 minimization” used in a wide range of applications from calorimeter calibra...

The random Fourier embedding methodology can be used to approximate the performance of non-linear kernel classifiers in linear time on the number of training examples. However, there still exists a non-trivial performance gap between the approximation and the nonlinear models, especially for the exponential χ kernel, one of the most powerful models for histograms. Based on analogies with Chebys...

The case of Q̂(χ1) · Q̂(χ1)-Q̂(χ2) · Q̂(χ2) mixing in the interacting boson model is studied within its mean-field approximation. It is shown that the criticality conditions lead to two classes of solutions and that χ1 and χ2 need to have an opposite sign to allow for prolate-oblate shape coexistence. No evidence for a stable triaxial minimum is found. Phase diagrams for selected cases have been co...

OBJECTIVE To compare the adverse maternal and neonatal outcomes of multiple pregnancy and singleton pregnancy from multiple medical centers in Beijing. METHODS Data concerning maternal and neonatal adverse outcomes in multiple and singleton pregnancies were collected from 15 hospitals in Beijing by a systemic cluster sampling survey conducted from 20 June to 30 November 2013. The SPSS softwar...