[en] We give two general trace theorems for functions used in transport theory

[en] Geometric quantum discord, proposed by Dakic et al (2010 Phys. Rev. Lett. 105 190502), is an important measure for bipartite correlations. In this paper, we generalize it to multipartite states, we call the generalized version geometric global quantum discord (GGQD). We characterize GGQD in different ways, give a lower bound for GGQD and provide some special states which allow analytical GGQD. (paper)

[en] Numerous investigations indicate an important relationship between atmospheric variables and various indicators of environmental contamination that affect public health [1]. Most of the series of meteorological variables used, as independent variables, have defects, Being the most common the lack of specific data or missing data lagoon [2]. There are numerous methods to solve this problem, Most of them require an assumption of normality in the behavior of the data and do not consider their spatial dependence. Through geostatistics, There is an alternative solution to this problem, Making use of regionalized variables, of random functions, of the variogram and Kriging, which is defined as the best linear unbiased estimator [5]. Finalize analysis with method validation, through the cross-validation method “leave one out” [6]. It is concluded that in annual series of atmospheric variables, with time-zone temporal resolution, that the Krigeage presented errors under 5%. (paper)

[en] This paper describes the comparison of Newton’s method and Steepest Descent method for determining the coordinates of earthquake source. Here, the Steepest Descent method is used because it is a Newton-based method. The earthquake case used in this research is Italian earthquake August 24, 2016, which has a seismic phase of Pg. The calculation was supported by Azimuth Coordinate equations to find the coordinates and Haversine formula to find the distance between five earthquake stations to the earthquake source. The final result of calculations was path’s graph from the iteration of Steepest Descent method. Moreover, the results will be compared with the results of Newton’s method that has been successfully approaching the point of earthquake source in the same case study of previous research. The result shows the number of final iterations of two methods using tolerance number 0.01, minimum velocity number 3093 m/s and three cases of initial guess in the form of city coordinate of Rome, Milan, and Palermo. Newton’s method generates 12 iterations in every case, Steepest Descent method generate 7, 6, 5 iteration respectively. However, the final numerical errors for Rome, Milan and Palermo initial guess are 0.1598 by Newton’s method, while Steepest Descent method are 0.1566, 0.1567 and 0.1567. (paper)

[en] A spatial quantile regression model is proposed to estimate the quantile curve for a given probability of non-exceedance, as function of locations and covariates. Canonical vines copulas are considered to represent the spatial dependence structure. The marginal at each location is an asymmetric Laplace distribution where the parameters are functions of the covariates. The full conditional quantile distribution is given using the Joe–Clayton copula. Simulations show the flexibility of the proposed model to estimate the quantiles with special dependence structures. A case study illustrates its applicability to estimate quantiles for spatial temperature anomalies.

[en] The data on the mean surface brightness of spiral single galaxies are compared to the data on the mean surface brightness of spiral binary galaxies. It is shown that the mean surface brightness of the spiral galaxies being the components of the pairs exceeds with high statistical significance that of isolated spiral galaxies. The increase of the mean surface brightness of the spiral galaxies in the pairs with decrease of linear distance between them is stated. The small correlation between the mean surface brightness of the components of the pairs is also revealed. It decreases with the increase of the linear distances between them

No abstract available

No abstract available

[en] The influence of the current channel radius on the electrostatic ion-cyclotron instability is investigated. The effective radius of the channel is varied by negatively biasing a ring electrode surrounding the circular positively biased electrode which draws the current. When the current channel is contracted to a few ion Larmor radii the instability is quenched. (author)

[en] On the base of a data base on the rocket profiles of electron density, measured by means of an electrostatic probe, is precised an empirical dependence of the elecron density of the lower ionosphere on the Sun zenits angle for day-time middle-latitude (49 deg N, 44 deg E) heliogeophysically nondisturbed conditions