Evaluation of the UMASEP-10 Version 2 Tool for Predicting All >10 MeV SEP Events of Solar Cycles 22, 23 and 24

The prediction of solar energetic particle (SEP) events may help to improve the mitigation of adverse effects on humans and technology in space. UMASEP (University of Málaga Solar particle Event Predictor) is an empirical model scheme that predicts SEP events. This scheme is based on a dual-model approach. The first model predicts well-connected events by using an improved lag-correlation algorithm for analyzing soft X-ray (SXR) and differential proton fluxes to estimate empirically the Sun–Earth magnetic connectivity. The second model predicts poorly connected events by analyzing the evolution of differential proton fluxes. This study presents the evaluation of UMASEP-10 version 2, a tool based on the aforementioned scheme for predicting all >10 MeV SEP events, including those without associated flare. The evaluation of this tool is presented in terms of the probability of detection (POD), false alarm ratio (FAR) and average warning time (AWT). The best performance was achieved for the solar cycle 24 (i.e., 2008–2019), obtaining a POD of 91.1% (41/45), a FAR of 12.8% (6/47) and an AWT of 2 h 46 min. These results show that UMASEP-10 version 2 obtains a high POD and low FAR mainly because it is able to detect true Sun–Earth magnetic connections.

A tutorial on reproducing a predefined autocovariance function through AR models: application to stationary homogeneous isotropic turbulence

Sequential methods for synthetic realisation of random processes have a number of advantages compared with spectral methods. In this article, the determination of optimal autoregressive (AR) models for reproducing a predefined target autocovariance function of a random process is addressed. To this end, a novel formulation of the problem is developed. This formulation is linear and generalises the well-known Yule-Walker (Y-W) equations and a recent approach based on restricted AR models (Krenk-Møller approach, K-M). Two main features characterise the introduced formulation: (i) flexibility in the choice for the autocovariance equations employed in the model determination, and (ii) flexibility in the definition of the AR model scheme. Both features were exploited by a genetic algorithm to obtain optimal AR models for the particular case of synthetic generation of homogeneous stationary isotropic turbulence time series. The obtained models improved those obtained with the Y-W and K-M approaches for the same model parsimony in terms of the global fitting of the target autocovariance function. Implications for the reproduced spectra are also discussed. The formulation for the multivariate case is also presented, highlighting the causes behind some computational bottlenecks.

NuSTAR monitoring of MAXI J1348-630: evidence of high density disc reflection

We present the broadband spectral analysis of all the six hard, intermediate and soft state NuSTAR observations of the recently discovered transient black hole X-ray binary MAXI J1348-630 during its first outburst in 2019. We first model the data with a combination of a multi-colour disc and a relativistic blurred reflection, and, whenever needed, a distant reflection. We find that this simple model scheme is inadequate in explaining the spectra, resulting in a very high iron abundance. We, therefore, explore the possibility of reflection from a high-density disc. We use two different sets of models to describe the high-density disc reflection: relxill-based reflection models, and reflionx-based ones. The reflionx-based high-density disc reflection models bring down the iron abundance to around the solar value, while the density is found to be $10^{20.3-21.4} \rm cm^{-3}$. We also find evidence of a high-velocity outflow in the form of ∼7.3 keV absorption lines. The consistency between the best-fit parameters for different epochs and the statistical significance of the corresponding model indicates the existence of high-density disc reflection in MAXI J1348-630.

Properties of Doubly Heavy Baryons

We revisited the mass spectra of the Ξcc++ baryon with positive and negative parity states using Hypercentral Constituent Quark Model Scheme with Coloumb plus screened potential. The ground state of the baryon has been determined by the LHCb experiment, and the anticipated excited state masses of the baryon have been compared with several theoretical methodologies. The transition magnetic moments of all heavy baryons Ξcc++, Ξcc+, Ωcc+, Ξbb0, Ξbb−, Ωbb−, Ξbc+, Ξbc0, Ωbc0 are also calculated and their values are −1.013 μN, 1.048 μN, 0.961 μN, −1.69 μN, 0.73 μN, 0.48 μN, −1.39 μN, 0.94 μN and 0.710 μN, respectively.

Weather Reasearch and Forecasting Model Simulation of a Snowfall Event in Southern Brazil

This study evaluates the reliability of the Weather Research and Forecasting (WRF) to simulate a snowfall event in the south of Brazil. The event in August 2013 was considered one of the most intense in recent years in the region with the highest topographic elevations between the states of Rio Grande do Sul (RS) and Santa Catarina (SC). The Snowfall in the mountain region of RS and SC was associated with the configuration involving a polar anticyclone and the intensification of an extratropical cyclone over the Atlantic Ocean. The WRF simulation results demonstrated the model's viability to predict the event, but without the magnitude representation of the phenomenon. The WRF simulation underestimated the results for the accumulated and area of the snowfall region, which may be linked to overestimations of surface and vertical air temperature and liquid water precipitation. These results were attributed to the choice of WRF Single–moment 6–class (WSM6) microphysics and in the Noah Land Surface Model scheme. Despite these limitations, WRF has proved to be an important tool for predicting the spatial and temporal distribution of snowfall and precipitation in the higher regions of southern Brazil.

The role of “personal factor” in British-Russian relations in 2016—2019

The article studies the key concepts and theories that had been forming the basis of Chilean multilateral diplomacy in 1990-2017. The author describes the essential pillars of Chilean foreign policy towards international organizations and offers its structured model-scheme which allows getting the systematic understanding of the related phenomena.

Conceptual and theoretical framework of multilateral diplomacy of Chile (1990—2017)

The article studies the key concepts and theories that had been forming the basis of Chilean multilateral diplomacy in 1990-2017. The author describes the essential pillars of Chilean foreign policy towards international organizations and offers its structured model-scheme which allows getting the systematic understanding of the related phenomena.

Why Should We Use Residual Thermodynamics for Calculation of Hydrate Phase Transitions?

The formation of natural gas hydrates during processing and transport of natural has historically been one of the motivations for research on hydrates. In recent years, there has been much focus on the use of hydrate as a phase for compact transport of natural gas, as well as many other applications such as desalination of seawater and the use of hydrate phase in heat pumps. The huge amounts of energy in the form of hydrates distributed in various ways in sediments is a hot topic many places around the world. Common to all these situations of hydrates in nature or industry is that temperature and pressure are both defined. Mathematically, this does not balance the number of independent variables minus conservation of mass and minus equilibrium conditions. There is a need for thermodynamic models for hydrates that can be used for non-equilibrium systems and hydrate formation from different phase, as well as different routes for hydrate dissociation. In this work we first discuss a residual thermodynamic model scheme with the more commonly used reference method for pressure temperature stability limits. However, the residual thermodynamic method stretches far beyond that to other routes for hydrate formation, such as hydrate formation from dissolved hydrate formers. More important, the residual thermodynamic method can be utilized for many thermodynamic properties involved in real hydrate systems. Consistent free energies and enthalpies are only two of these properties. In non-equilibrium systems, a consistent thermodynamic reference system (ideal gas) makes it easier to evaluate most likely distribution of phases and compositions.

Design of Conceptual Model for RaisingAwareness of Digital Threats

In today’s information-communication environment and the connected world awareness of and preparedness for digital threats is of utmost importance for organizational systems. It is not possible to fully guard against or eliminate all digital threats but with an educated and trained awareness and recognizing, acknowledgment and management of the risks along with appropriate policies, tactics, techniques, procedures and processes in place organizational systems are competent to become digital resilient. In this paper our aim is to investigate how digital threat awareness can improve digital resilience. Related to this the goal is to identify digital threat awareness components within cybersecurity and digital security. In this regard we used modelbased approach and methodology to create model scheme so the novel Cyber Resilience Model within digital resilience concept is created. Digital resilience modelling approach takes account components of digital threats within digital security and engagement.

Analysis of crude mineral sample preparation schemes

Introduction. Sample preparation schemes are multi-stage. Sample reduction in the process of preparation introduces extra inaccuracy in the result of sampling, consequently, sample preparation schemes inaccuracy should be calculated with further selection of its rational parameters. Research methodology is based on calculation by the formula of sample reduction random inaccuracy. Inaccuracy calculation of a sample preparation scheme. Calculation has been carries out of the scheme recommended by GOST 14180-80. Paradoxical growth of inaccuracy of sample preparation has been shown with ore homogeneity growth. Determination of sample mass by the stages of preparation. Standards and techniques of ore and nonferrous metals concentrates sampling for the creation of sample preparation schemes recommend finding the coefficient in minimum mass formula depending on the mass fraction variation coefficient in the sampled product. Sample preparation is carried out in laboratory conditions, and sample mass cannot depend on this coefficient of variation. Sample inhomogeneity in the laboratory depends only on the inhomogeneity of separate lumps of a sample. Sample inhomogeneity in the preparation laboratory is defined by lump dispersion, and the coefficient is the function of this dispersion, admissible inaccuracy of sample reduction and the dimensions of grain impregnations of the mineral which contains the analyte. 78 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 1. 2020 ISSN 0536-1028 For each factory, individual coefficient can be found, and sample masses can be calculated by the stages of preparation. Analysis of sample preparation schemes. Sample preparation scheme inaccuracy formula is given. Calculation and analysis of the model scheme of sample preparation according to GOST 14180-80 have shown that at the third crushing stage the sample is advisable to be crushed not up to 3, but up to 2 mm, and the recommended sample size at the final stage 8.08 hardly improves the result of preparation, that is why the previous recommendation of 0.1 mm can be used.