Cyclotron resonant scattering feature simulations. I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling

Electron cyclotron resonant scattering features (CRSFs) are observed as absorption-like lines in the spectra of X-ray pulsars. A significant fraction of the computing time for Monte Carlo simulations of these quantum mechanical features is spent on the calculation of the mean free path for each individual photon before scattering, since it involves a complex numerical integration over the scattering cross section and the (thermal) velocity distribution of the scattering electrons. We aim to numerically calculate interpolation tables which can be used in CRSF simulations to sample the mean free path of the scattering photon and the momentum of the scattering electron. The tables also contain all the information required for sampling the scattering electron's final spin. The tables were calculated using an adaptive Simpson integration scheme. The energy and angle grids were refined until a prescribed accuracy is reached. The tables are used by our simulation code to produce artificial CRSF spectra. The electron momenta sampled during these simulations were analyzed and justified using theoretically determined boundaries. We present a complete set of tables suited for mean free path calculations of Monte Carlo simulations of the cyclotron scattering process for conditions expected in typical X-ray pulsar accretion columns (0.01<B/B_{crit}<=0.12, where B_{crit}=4.413x10^{13} G and 3keV<=kT<15keV). The sampling of the tables is chosen such that the results have an estimated relative error of at most 1/15 for all points in the grid. The tables are available online at http://www.sternwarte.uni-erlangen.de/research/cyclo.Comment: A&A, in pres

Energy risk management in urban projects management

global and significantly affect (negatively, positively) the state and development of the national and world economy. The purpose of the paper is the formation of methodical-practical foundations of energy risk management in the energy sector.METHODS: The matrix method was used in building the energy security risk assessment matrix. Economic-mathematical modeling was used. Depending on the characteristics of the dynamic series and the available information, the methods of analytical alignment, smoothing using the moving average, the average absolute increase, and the average coefficient of change were applied.FINDINGS: The energy security risk assessment matrix was created. The development of a strategy for the behavior of subjects of market relations in the electricity market should be based not only on the results of risk identification and assessment and the developed risk management plan, but also on the risk response plan and the method of their control (monitoring). The coefficient of use of the installed energy capacity was in the range of 32–26% in Poland in 2021. Calculations of average annual growth rates for each of the dynamic series give reason to state that the highest growth rates of dependence on energy imports were characteristic of coal (+4.17%) and the lowest ones — of oil (+0.35%) during 1990–2021. Considering the forecast values for 2030, a certain decrease in the growth rate of dependence on the import of energy resources (for coal and oil) and an increase- for gas are expected.CONCLUSION: As a conclusion, the method of forecasting the total final energy consumption of the country was improved for forecasting the amount of energy resources in order to use it for building an energy policy that considers such variables as the economic situation and the political situation in the country. The formation of a risk response plan should be based on management plans and documentation of risk manifestations, intellectual and organizational assets of the economic entity (generalized risk management experience, management strategies, templates, etc.). manifestations, intellectual and organizational assets of the economic entity (generalized risk management experience, management strategies, templates, etc.)

Assessing software defection prediction performance: why using the Matthews correlation coefficient matters

China Scholarship Counci

Management of Migratory Exchange Taking into Account Features of Standard Regulation of Recognition / Validation and an Assessment of Qualifications Within the CIS Countries, EEU and BRICS

Legal regulation of national qualifications systems in countries-participants of the CIS, EAEU and the BRICS and the prospects for cooperation in the field of free labor-force movement within these unions, connect with the solution of problems of mutual recognition of occupation qualifications, their level of qualifications and methods of assessment within the subjects of migration transfer processes

Randomized Reference Classifier with Gaussian Distribution and Soft Confusion Matrix Applied to the Improving Weak Classifiers

In this paper, an issue of building the RRC model using probability distributions other than beta distribution is addressed. More precisely, in this paper, we propose to build the RRR model using the truncated normal distribution. Heuristic procedures for expected value and the variance of the truncated-normal distribution are also proposed. The proposed approach is tested using SCM-based model for testing the consequences of applying the truncated normal distribution in the RRC model. The experimental evaluation is performed using four different base classifiers and seven quality measures. The results showed that the proposed approach is comparable to the RRC model built using beta distribution. What is more, for some base classifiers, the truncated-normal-based SCM algorithm turned out to be better at discovering objects coming from minority classes.Comment: arXiv admin note: text overlap with arXiv:1901.0882

Foveated image processing for faster object detection and recognition in embedded systems using deep convolutional neural networks

Object detection and recognition algorithms using deep convolutional neural networks (CNNs) tend to be computationally intensive to implement. This presents a particular challenge for embedded systems, such as mobile robots, where the computational resources tend to be far less than for workstations. As an alternative to standard, uniformly sampled images, we propose the use of foveated image sampling here to reduce the size of images, which are faster to process in a CNN due to the reduced number of convolution operations. We evaluate object detection and recognition on the Microsoft COCO database, using foveated image sampling at different image sizes, ranging from 416×416 to 96×96 pixels, on an embedded GPU – an NVIDIA Jetson TX2 with 256 CUDA cores. The results show that it is possible to achieve a 4× speed-up in frame rates, from 3.59 FPS to 15.24 FPS, using 416×416 and 128×128 pixel images respectively. For foveated sampling, this image size reduction led to just a small decrease in recall performance in the foveal region, to 92.0% of the baseline performance with full-sized images, compared to a significant decrease to 50.1% of baseline recall performance in uniformly sampled images, demonstrating the advantage of foveated sampling

NuSTAR observation of GRO J1744-28 at low mass accretion rate

We present the spectral analysis of the LMXB GRO J1744-28 using $\sim$29 ks of NuSTAR data taken in 2017 February at a low luminosity of $3.2\times 10^{36}$ erg/s (3-50 keV). The continuum spectrum is modeled with an absorbed power-law with exponential cut-off, and an additional iron line component. We find no obvious indications for a CRSF and therefore perform a detailed cyclotron line search using statistical methods on the pulse phase-averaged as well as phase-resolved spectra. The previously detected Type II X-ray bursts are absent. Clear pulsations at a period of 2.141124(9) Hz are detected. The pulse profile shows an indication of a secondary peak, which was not seen at higher flux. The 4$\sigma$ upper limit for the strength of a CRSF in the 3-20 keV band is 0.07 keV, lower than the strength of the line found at higher luminosity. The detection of pulsations shows that the source did not enter the "propeller" regime, even though the source flux of $4.15\times 10^{-10}$ erg/cm$^{2}$/s was almost one order of magnitude below the threshold for the propeller regime claimed in previous studies on this source. The transition into the propeller regime in GRO J1744-28 must therefore be below a luminosity of $3.2\times 10^{36}$ erg/s, which implies a surface magnetic field $\lesssim 2.9\times 10^{11}$ G and mass accretion rate $\lesssim 1.7\times 10^{16}$ g/s. A change of the CRSF depth as function of luminosity is not unexpected and has been observed in other sources. This result possibly implies a change in emission geometry as function of mass accretion rate to reduce the depth of the line below our detection limit

Evaluation of various planar gaseous detectors with CsI photocathodes for the detection of primary scintillation light from noble gases

Noble gases and liquids are excellent scintillators and this opens a unique opportunity to directly detect the primary scintillation light produced in these media by photons or particles. This signal can be used for several purposes, for example as a start signal for TPCs or for particles identification. Usually photomultipliers (PMs) are used for the detection of the scintillation light. In our previous work we have demonstrated that costly PMs could be replaced by gaseous detectors with CsI photocathodes . Such detectors have the same quantum efficiency as the best PMs but at the same time are cheap, simple and have high position and time resolutions. The aim of this work is to evaluate various planar type gaseous detectors with CsI photocahodes in order to choose the best one for the detection of the primary scintillation light from noble gases and liquids

Experience of application of prourous kinase in acute coronary syndrome with ST-segment rising at the pre-hospital stage

The article analyzed 14 cases of acute coronary syndrome with ST-segment elevation (STEMI-ACS), which received thrombolytic (TLT) at the prehospital stage with the preparation of prourokinase for 2018 in the city of Revda, Sverdlovsk region, and determined the clinical efficacy of this procedure and electrocardiography (ECG).В статье проанализированы 14 случаев острого коронарного синдрома с подъемом сегмента ST (ОКСспST), которые получили тромболитическую (ТЛТ) на догоспитальном этапе препаратом проурокиназой за 2018 года в г. Ревда Свердловской области и определена клиническая эффективность данной процедуры и по данным электрокардиографии (ЭКГ)