135 results on '"Adam, Gh."'
Search Results
2. The boundary layer problem in Bayesian adaptive quadrature
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Adam, Gh. and Adam, S.
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- 2008
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3. Mean field solutions to singlet hopping and superconducting pairing within a two-band Hubbard model
- Author
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Adam, S. and Adam, Gh.
- Published
- 2008
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4. Summation Paths in Clenshaw-Curtis Quadrature
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Adam S. and Adam Gh.
- Subjects
Physics ,QC1-999 - Abstract
Two topics concerning the use of Clenshaw-Curtis quadrature within the Bayesian automatic adaptive quadrature approach to the numerical solution of Riemann integrals are considered. First, it is found that the efficient floating point computation of the coefficients of the Chebyshev series expansion of the integrand is to be done within a mathematical structure consisting of the union of coefficient families ordered into complete binary trees. Second, the scrutiny of the decay rates of the involved even and odd rank Chebyshev expansion coefficients with the increase of their rank labels enables the definition of Bayesian decision paths for the advancement to the numerical output.
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- 2016
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5. Length Scales in Bayesian Automatic Adaptive Quadrature
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Adam Gh. and Adam S.
- Subjects
Physics ,QC1-999 - Abstract
Two conceptual developments in the Bayesian automatic adaptive quadrature approach to the numerical solution of one-dimensional Riemann integrals [Gh. Adam, S. Adam, Springer LNCS 7125, 1–16 (2012)] are reported. First, it is shown that the numerical quadrature which avoids the overcomputing and minimizes the hidden floating point loss of precision asks for the consideration of three classes of integration domain lengths endowed with specific quadrature sums: microscopic (trapezoidal rule), mesoscopic (Simpson rule), and macroscopic (quadrature sums of high algebraic degrees of precision). Second, sensitive diagnostic tools for the Bayesian inference on macroscopic ranges, coming from the use of Clenshaw-Curtis quadrature, are derived.
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- 2016
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6. Exchange and spin-fluctuation mechanisms of superconductivity in cuprates
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Plakida, N. M., Anton, L., Adam, S., and Adam, Gh.
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- 2003
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7. Reliability conditions in quadrature algorithms
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Adam, Gh, Adam, S, and Plakida, N.M
- Published
- 2003
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8. CORSIKA Based Simulations of Background in Baikal Experiment.
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Adam, Gh., Buša, J., Hnatič, M., and Pastirčák, Blahoslav
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NEUTRINO detectors , *METAPHYSICAL cosmology , *MUONS , *COSMIC rays , *DETECTORS - Abstract
The Baikal experiment aims to register cosmological neutrinos and map the high-energy neutrino sky in the Southern Hemisphere including the region of the Galactic Center. It will use a km3-scale high-energy neutrino telescope located in the southern basin of the Lake Baikal. The northern location of the detector site allows direct observation of the Galactic Center in more than 75 % of the astronomical time. The selection of events from neutrino induced upward going muons, suggests a fairly reliable estimation of the expected background from atmospheric muons. The procedure for simulating background events from atmospheric muons in an array is performed in several steps. The CORSIKA 7.64 was used to simulate the flux of atmospheric muons at the sea level with appropriate chemical composition of the primary cosmic rays. The muon propagation through water and rock to the array level was then simulated with the MUM code. As the last step of the simulation chain, the detector response to the Cherenkov radiation of muons was estimated by taking into account the features of the array measuring systems was performed. The main features of the CORSIKA Monte Carlo code and the next steps of the simulation chain are summarized. The physical models embedded in CORSIKA are described. Application of the full simulation chain is demonstrated. [ABSTRACT FROM AUTHOR]
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- 2020
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9. Software Development for the BM@N Experiment at NICA: Challenges and Status.
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Adam, Gh., Buša, J., Hnatič, M., Gertsenberger, Konstantin, Merts, Sergey, Gabdrakhmanov, Ilnur, Filozova, Irina, Alexandrov, Igor, Alexandrov, Evgeny, Moshkin, Andrey, and Chebotov, Alexander
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COMPUTER software development , *IONS , *DIGITIZATION , *COMPUTER software , *DATABASES - Abstract
A new generation of experiments on relativistic nuclear physics is planned to be started in the nearest years at the Nuclotron-based Ion Collider facility (NICA) under construction at the Joint Institute for Nuclear Research in Dubna. The fixed target experiment BM@N (Baryonic Matter at Nuclotron) is considered as a first stage towards the implementation of the physics program available at NICA. For a successful accomplishment of the BM@N physics program, a well-developed and tested software package for simulation, digitization, reconstruction and analysis of collision events and other supporting tasks is of utmost importance. The data flow scheme of the experiment is shown. Offine and online software systems, such as the main BmnRoot framework, databases of the experiment, data monitoring and others providing information support for the experiment are presented. The implementation of the software systems is a necessary stage for the successful operation of the BM@N experiment. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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10. A Probabilistic Approach to the Simulation of Data Processing Centers.
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Adam, Gh., Buša, J., Hnatič, M., Korenkov, Vladimir, Nechaevskiy, Andrey, Ososkov, Gennady, Priakhina, Daria, and Trofimov, Vladimir
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ELECTRONIC data processing , *COMPUTERS , *COMPUTER systems , *SIMULATION games , *BACK up systems - Abstract
The simulation of a data center for the storage and processing of data from the NICA detectors is an important step towards the creation of the NICA computing system. A model developed in the frame of the probabilistic approach to the solution enables decisions concerning a lower bound of the necessary resources for full data transfer of the detector records to the storage system. [ABSTRACT FROM AUTHOR]
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- 2020
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11. Nonparametric Tests for Purity of Low Statistics Data.
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Adam, Gh., Buša, J., Hnatič, M., and Zlokazov, Victor B.
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NONPARAMETRIC estimation , *NUMERIC databases , *STATISTICS , *EXPONENTIAL functions , *STANDARD deviations - Abstract
The nonparametric methods are most suitable for tasks facing the uncertainty or complexity of models and the small statistics of the analyzed data. They are irreplaceable in those cases when high tempo of the analysis is required. [ABSTRACT FROM AUTHOR]
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- 2020
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12. Experimental Data Processing Using Shift Methods.
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Adam, Gh., Buša, J., Hnatič, M., and Novikov-Borodin, Andrey
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ELECTRONIC data processing , *KERNEL (Mathematics) , *PROTON therapy , *STATISTICS , *COMPARATIVE studies - Abstract
The numerical methods of step-by-step and combined shifts are proposed for correction and reconstruction the experimental data convolved with different blur kernels. Methods use a shift technique for the direct deconvolution of experimental data, they are fast and effective for data reconstruction, especially, in the case of discrete measurements. The comparative analysis of proposed methods is presented, inaccuracies of reconstruction with different blur kernels, different volumes of data and noise levels are estimated. There are presented the examples of using the shift methods in processing the statistical data of TOF neutron spectrometers and in planning the proton therapy treatment. The multi-dimensional data processing using shift methods is considered. The examples of renewal the 2D images blurred by uniform motion and distorted with the Gaussian-like blur kernels are presented. [ABSTRACT FROM AUTHOR]
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- 2020
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13. Nested Intellectual Data Grouping and Clusterization for the Interactive Visual Explorer.
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Adam, Gh., Buša, J., Hnatič, M., Grigorieva, Maria, Titov, Mikhail, Galkin, Timofei, and Milman, Igal
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INTELLECTUALS , *VISUAL analytics , *DATA analysis , *DOCUMENT clustering , *COMPUTER software - Abstract
The Interactive Visual Explorer (InVEx) application is designed as a visual analytics tool for Big Data analysis. Visual analytics is an integral approach to data analysis, combining methods of intellectual data analysis with advanced interactive visualization. One of the main objectives of InVExis to process large data samples by decreasing their level of detail (LoD).The proposed approach includes clustering as well as flexible grouping by different parameters, providing the exploration of data from the lowest to the highest level of details. The results of grouping and clusterization arevisualized using interactive 3D scene and parallel coordinates, allowing the user to gain insight into data, to explore hidden correlations and trends of parameters. [ABSTRACT FROM AUTHOR]
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- 2020
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14. System for Automatic Processing and Analysis of MRI/fMRI Data on the Kurchatov Institute Supercomputer.
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Adam, Gh., Buša, J., Hnatič, M., Enyagina, Irina M., Polyakov, Andrey N., Poyda, Alexey A., and Ushakov, Vadim L.
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AUTOMATICITY (Learning process) , *MAGNETIC resonance imaging , *FUNCTIONAL magnetic resonance imaging , *TOMOGRAPHY , *MATHEMATICAL models - Abstract
This paper presents the Computer Model of the System for Automatic Processing and Analysis of MRI/fMRI tomography data, obtained at the Kurchatov Institute Resource Center "Cognimed". The System is based on the "Digital Lab" IT-Platform, involving the Kurchatov Institute Supercomputer Cluster HPC4, which allows speeding up the processing of data for groups (2–350 subjects) by parallelization of computations on the supercomputer nodes (1 subject – 1 node). The proposed System allows scientists to remotely use the installed on the supercomputer specialized software to process and analyze MRI/fMRI data; organizes a unified data storage; permits the work with data by web a interface. The System also enables the use of program modules developed by KI researchers which implement mathematical methods to improve data analysis results. As an example of the realization of this Computer Model, the Module "MRI FS" is presented that provides automatic processing and analysis of MRI data using the open specialized software FreeSurfer v.6.0. [ABSTRACT FROM AUTHOR]
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- 2020
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15. BM@N Tracking with Novel Deep Learning Methods.
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Adam, Gh., Buša, J., Hnatič, M., Goncharov, Pavel, Shchavelev, Egor, Ososkov, Gennady, and Baranov, Dmitriy
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DEEP learning , *NEURAL circuitry , *ELECTRONIC commerce , *KALMAN filtering , *MONTE Carlo method - Abstract
Three deep tracking methods are presented for the BM@N experiment GEM track detector, which differ in their concepts. The first is a two-stage method with data preprocessing by a directional search in the k-d tree to find all possible candidates for tracks, and then use a deep recurrent neural network to classify them by true and ghost tracks. The second end-to-end method used a deep recurrent neural network to extrapolate the initial tracks, similar to the Kalman filter, which learns necessary parameters from the data. The third method implements our new attempt to adapt the neural graph network approach developed in the HEP.TrkX project at CERN to GEM-specific data. The results of applying these three methods to simulated events are presented. [ABSTRACT FROM AUTHOR]
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- 2020
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16. High-Performance Optimization of Algorithms Used in the BM@N Experiment of the NICA Project.
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Adam, Gh., Buša, J., Hnatič, M., Merts, Sergei, Nemnyugin, Sergei, Roudnev, Vladimir, and Stepanova, Margarita
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BOTTLENECKS (Manufacturing) , *NUMERICAL analysis , *PARTICLE beam extraction , *MONTE Carlo method , *COMPILERS (Computer programs) - Abstract
Results of high-performance optimization of BmnRoot software modules are presented. The BmnRoot package used in the BM@N experiment of the NICA project plays a crucial role in the simulation and event reconstruction so its performance should be maximized to make the data processing efficient. Results of performance analysis on representative testcases are given and bottlenecks are localized. Most suitable approaches to BmnRoot optimization are chosen and numerical estimates of the scalability of the parallelized modules for event reconstruction are presented. [ABSTRACT FROM AUTHOR]
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- 2020
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17. Development of the BM@N Web Monitoring.
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Adam, Gh., Buša, J., Hnatič, M., Gabdrakhmanov, Ilnur R., and Merts, Sergei P.
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DETECTORS , *HISTOGRAMS , *QUARK-gluon plasma , *TIME-of-flight measurements , *DATA quality - Abstract
The BM@N experiment is a fixed target experiment and the first stage of the NICA project. Its development is of great importance for the NICA experiment as a whole. In order to effectively conduct the experiment, a convenient and unified monitoring tool is needed. The monitoring system backend is based on the FairRoot package while its frontend uses the CERN jsROOT library. The user is able to monitor any detector subsystem, select specific detector station, plane, time or strip profile histograms in 1/2/3D view. The QA functions currently are presented by reference run auto-selecting and consequent overlaying histograms. [ABSTRACT FROM AUTHOR]
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- 2020
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18. Deep Siamese Networks for Plant Disease Detection.
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Adam, Gh., Buša, J., Hnatič, M., Goncharov, Pavel, Uzhinskiy, Alexander, Ososkov, Gennady, Nechaevskiy, Andrey, and Zudikhina, Julia
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DEEP learning , *RURAL families , *FOOD security , *DISEASED plants , *K-nearest neighbor classification - Abstract
Crop losses are a major threat to the wellbeing of rural families, to the economy and governments, and to food security worldwide. The goal of our research is to develop a multi-functional platform to help the farming community to tilt against plant diseases. In our previous works, we reported about the creation of a special database of healthy and diseased plants' leaves consisting of five sets of grapes images and proposed a special classification model based on a deep siamese network followed by k-nearest neighbors (KNN) classifier. Then we extended our database to five sets of images for grape, corn, and wheat – 611 images in total. Since after this extension the classification accuracy decreased to 86 %, we propose in this paper a novel architecture with a deep siamese network as feature extractor and a single-layer perceptron as a classifier that results in a significant gain of accuracy, up to 96 %. [ABSTRACT FROM AUTHOR]
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- 2020
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19. Heavy Fragments Identification Using Energy Loss Method in the STS Detector of the CBM Experiment.
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Adam, Gh., Buša, J., Hnatič, M., Derenovskaya, Olga, Ivanov, Victor, Vassiliev, Iorii, and Russov, Yurii
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ENERGY dissipation , *HEAVY ions , *ANTIPROTONS , *TRANSITION radiation detector , *HYPERFRAGMENTS - Abstract
The current paper presents the possibility of heavy fragments identification using energy loss method and ωnk criterion in the STS detector of the CBM experiment. [ABSTRACT FROM AUTHOR]
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- 2020
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20. Architecture of a Compact Data GRID Cluster for Teaching Modern Methods of Data Mining in the Virtual Computer Lab.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Belov, Mikhail, Korenkov, Vladimir, Tokareva, Nadezhda, and Cheremisina, Eugenia
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DATA mining , *VIRTUAL machine systems , *BIG data , *BACK up systems , *ELECTRONIC data processing - Abstract
This paper discusses the architecture of a compact Data GRID cluster for teaching new methods of Big Data analytics in the Virtual Computer Lab. Its main destination is training highly qualified IT-professionals able to solve efficiently problems of distributed data storage and processing, drawing insights, data mining, and mathematical modeling based on these data. The Virtual Computer Lab was created and successfully operated by the experts of the System Analysis and Control Department at the Dubna State University in collaboration with the Laboratory of Information Technologies (Joint Institute for Nuclear Research). [ABSTRACT FROM AUTHOR]
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- 2020
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21. Track Reconstruction in the BM@N Experiment.
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Adam, Gh., Buša, J., Hnatič, M., Baranov, Dmitriy, Batyuk, Pavel, Gertsenberger, Konstantin, and Merts, Sergei
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RUNNING , *COMPUTER software development , *HEAVY-ion atom collisions , *MONTE Carlo method , *QUALITY assurance - Abstract
The BM@N experiment (Dubna, JINR) within the NICA complex is a running fixed target experiment. This paper mainly discusses the software support of the experimen and presents the status of the development and testing algorithms to be used for the reconstruction of heavy-ion collisions. Algorithms of reconstruction are described and tested with Monte Carlo input demonstrating a reasonable level of quality assurance. First results on particle identification being a good probe to estimate quality of reconstruction are also mentioned. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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22. Finite Time Correlations and Compressibility Effects in the Three-Dimensional Kraichnan Model.
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Adam, Gh., Buša, J., Hnatič, M., and Menkyna, Martin
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FINITE element method , *GAUSSIAN function , *VELOCITY , *COMPRESSIBILITY , *SPATIAL analysis (Statistics) - Abstract
Using the field theoretic renormalization group technique the simultaneous influence of the compressibility and finite time correlations of the non-solenoidal Gaussian velocity field on the advection of a passive scalar field is studied within the generalized Kraichnan model in three spatial dimensions up to the second-order approximation in the corresponding perturbative expansion. All possible infrared stable fixed points of the model, which drive the corresponding scaling regimes of the model, are identified and their regions of the infrared stability in the model parametric space are discussed. It is shown that, depending on the value of the parameter that drives the compressibility of the system, there exists a gap in the parametric space between the regions where the model with the frozen velocity field and the model with finite-time correlations of the velocity field are stable or there exists an overlap between them. [ABSTRACT FROM AUTHOR]
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- 2020
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23. Evolution and Perspectives of the Service for Parallel Applications Running at JINR Multifunctional Information and Computing Complex.
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Adam, Gh., Buša, J., Hnatič, M., Balashov, Nikita, Kutovskiy, Nikolay, Priakhina, Daria, and Sokolov, Ivan
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CLOUD computing , *SCIENTIFIC computing , *INTERFACES (Physical sciences) , *FILES (Records) , *JOB descriptions - Abstract
Nowadays scientists use cloud computing as a routine tool in a lot of fields of their research. Various Multifunctional Information and Computing Complex (MICC) resources are provided for JINR users to perform a wide range of scientific computations. The JINR cloud service for parallel applications was developed in order to simplify scientists' work on running similar tasks but on different MICC resources and also to speed up the process of reaching significant results. There are several components with a flexible and modular architecture that allow running a various number of applications using different types of computational resources. The service is constantly developing and improving with the help of the users' feedback. Some changes in web-interface were made to improve users' experience: there was added the possibility to choose a certain type of particular application, to set a description for a job, to run multiple tasks, to notify a user about successful job submission and its completion. Moreover, accessibility of job results was reworked: when the job is done, its output is uploaded at the external file storage, where it becomes available at the auto-generated unique URL for downloading by the user and further analysis and/or visualization. [ABSTRACT FROM AUTHOR]
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- 2020
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24. Efficient and Scalable Approach to Equilibrium Conditional Simulation of Gibbs Markov Random Fields.
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Adam, Gh., Buša, J., Hnatič, M., Žukovič, Milan, and Hristopulos, Dionissios T.
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EQUILIBRIUM , *MARKOV processes , *MONTE Carlo method , *PLANAR motion , *LOW temperatures - Abstract
We study the performance of an automated hybrid Monte Carlo (HMC) approach for conditional simulation of a recently proposed, single-parameter Gibbs Markov random field. This is based on a modified version of the planar rotator (MPR) model and is used for efficient gap filling in gridded data. HMC combines the deterministic over-relaxation method and the stochastic Metropolis update with dynamically adjusted restriction and performs automatic detection of the crossover to the targeted equilibrium state. We focus on the ability of the algorithm to efficiently drive the system to equilibrium at very low temperatures even with sparse conditioning data. These conditions are the most challenging computationally, requiring extremely long relaxation times if simulated by means of the standard Metropolis algorithm. We demonstrate that HMC has considerable benefits in terms of both computational efficiency and prediction performance of the MPR method. [ABSTRACT FROM AUTHOR]
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- 2020
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25. A Geometric View on Quantum Tensor Networks.
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Adam, Gh., Buša, J., Hnatič, M., and Tsirulev, Alexander
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QUANTUM communication , *CALCULUS of tensors , *RIEMANN-Hilbert problems , *COVARIANT field theories , *POLYNOMIALS - Abstract
Tensor network states and algorithms play a key role in understanding the structure of complex quantum systems and their entanglement properties. This report is devoted to the problem of the construction of an arbitrary quantum state using the differential geometric scheme of covariant series in Riemann normal coordinates. The building blocks of the scheme are polynomials in the Pauli operators with the coefficients specified by the curvature, torsion, and their covariant derivatives on some base manifold. The problem of measuring the entanglement of multipartite mixed states is shortly discussed. [ABSTRACT FROM AUTHOR]
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- 2020
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26. Computation of 3D Water Flows by the Double Potential Method for the Simulation of Electromagnetic Water Purification.
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Adam, Gh., Buša, J., Hnatič, M., Tarasov, Nikita, Polyakov, Sergey, and Kudryashova, Tatiana
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THREE-dimensional modeling , *HYDRAULICS , *ELECTROMAGNETIC devices , *WATER purification , *ELECTROMAGNETIC fields - Abstract
In this paper, we discuss the modeling of the electromagnetic water purification. This model requires a velocity distribution in a study domain. For that purpose, the double potential method for simulating incompressible viscous fluid flows was used. The system of equations was discretized with the help of the finite volume method using an exponential transformation for the vortex calculation. As a result, a software implementation of the developed numerical scheme was obtained. The simulation of the three-dimensional flow was carried out in a study domain. The results were compared with Ansys CFD. The comparison showed a good degree of consistency between the two distributions. Using the obtained velocity field, we simulated the process of water purification using the induction of the electromagnetic field. [ABSTRACT FROM AUTHOR]
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- 2020
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27. Development of the Geometry Database for the BM@N Experiment of the NICA Project.
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Adam, Gh., Buša, J., Hnatič, M., Akishina, Elena, Alexandrov, Evgeny, Alexandrov, Igor, Filozova, Irina, Gertsenberger, Konstantin, Ivanov, Victor, Priakhina, Daria, and Shestakova, Galina
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GEOMETRY , *DATABASES , *GRAPHICAL user interfaces , *APPLICATION program interfaces , *COMPUTER software - Abstract
The article is dedicated to the current state of the Geometry Database for the BM@N experiment of the NICA project. The main goal of the database is to provide a central storage of the BM@N geometries, convenient tools for managing its geometry modules, various software assembling versions of the BM@N setup as a combination of modules and additional files providing support for a set of versions. Both the Graphical User Interface (GUI) and the Application Programming Interface (API) have been developed. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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28. Global Thermodynamic Properties of Complex Spin Systems Calculated from Density of States and Indirectly by Thermodynamic Integration Method.
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Adam, Gh., Buša, J., Hnatič, M., Semjan, Marek, and Žukovič, Milan
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THERMODYNAMICS , *DENSITY , *MONTE Carlo method , *ENTROPY , *ANTIFERROMAGNETIC materials - Abstract
Evaluation of global thermodynamic properties such as the entropy or the free energy of complex systems featuring a high degree of frustration or disorder is often desirable. Nevertheless, they cannot be measured directly in standard Monte Carlo simulation. Therefore, they are either evaluated indirectly from the directly measured quantities, for example by the thermodynamic integration method (TIM), or by applying more sophisticated simulation methods, such as the Wang-Landau (WL) algorithm, which can directly sample density of states. In the present investigation we compare the performance of the WL and TIM methods for the calculation of the entropy of an Ising antiferromagnetic system on a Kagome lattice – a typical example of a complex spin system with high geometrical frustration resulting in a non-zero residual entropy the value of which is exactly known. It is found that the easier to implement TIM can yield results of comparable accuracy with that of the more involved WL method. [ABSTRACT FROM AUTHOR]
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- 2020
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29. KANTBP 4M Program for Solving the Scattering Problem for a System of Ordinary Second-Order Differential Equations.
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Adam, Gh., Buša, J., Hnatič, M., Chuluunbaatar, Galmandakh, Gusev, Alexander A., Chuluunbaatar, Ochbadrakh, Vinitsky, Sergue I., and Le Hai, Luong
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SCATTERING (Mathematics) , *DIFFERENTIAL equations , *BOUNDARY value problems , *FINITE element method , *HOMOGENEOUS spaces - Abstract
We report an upgrade of the program KANTBP 4M implemented in the computer algebra system MAPLE for solving, with a given accuracy, the multichannel scattering problem, which is reduced to a boundary-value problem for a system of ordinary differential equations of the second order with continuous or piecewise continuous real or complex-valued coeffcients. The solution over a finite interval is subject to mixed homogeneous boundary conditions: Dirichlet and/or Neumann, and/or of the third kind. The discretization of the boundary problem is implemented by means of the finite element method with the Lagrange or Hermite interpolation polynomials. The effciency of the proposed algorithm is demonstrated by solving a multichannel scattering problem with coupling of channels in both the reaction region and the asymptotic one. [ABSTRACT FROM AUTHOR]
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- 2020
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30. Multipartite Quantum Systems and Representations of Wreath Products.
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Adam, Gh., Buša, J., Hnatič, M., and Kornyak, Vladimir
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WREATH products (Group theory) , *HILBERT space , *INVARIANTS (Mathematics) , *QUANTUM correlations , *COMPUTATIONAL complexity - Abstract
The multipartite quantum systems are of particular interest for the study of such phenomena as entanglement and non-local correlations. The symmetry group of the whole multipartite system is the wreath product of the group acting in the "local" Hilbert space and the group of permutations of the constituents. The dimension of the Hilbert space of a multipartite system depends exponentially on the number of constituents, which leads to computational difficulties. We describe an algorithm for decomposing representations of wreath products into irreducible components. The C implementation of the algorithm copes with representations of dimensions in quadrillions. The program, in particular, builds irreducible invariant projectors in the Hilbert space of a multipartite system. The expressions for these projectors are tensor product polynomials. This structure is convenient for efficient computation of quantum correlations in multipartite systems with a large number of constituents. [ABSTRACT FROM AUTHOR]
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- 2020
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31. Comparative Performance Analysis of Neural Network Real-Time Object Detections in Different Implementations.
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Adam, Gh., Buša, J., Hnatič, M., Stadnik, Alexey V., Sazhin, Pavel S., and Hnatic, Slavomir
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NEURAL circuitry , *COMPUTER vision , *HARDWARE , *COMPARATIVE studies , *FEASIBILITY problem (Mathematical optimization) - Abstract
The performance of neural networks is one of the most important topics in the field of computer vision. In this work, we analyze the speed of object detection using the well-known YOLOv3 neural network architecture in different frameworks under different hardware requirements. We obtain results, which allow us to formulate preliminary qualitative conclusions about the feasibility of various hardware scenarios to solve tasks in real-time environments. [ABSTRACT FROM AUTHOR]
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- 2020
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32. Numerical Precision Effects on GPU Simulation of Massive Spatial Data, Based on the Modified Planar Rotator Model.
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Adam, Gh., Buša, J., Hnatič, M., Lach, Matúš, Borovský, Michal, and Žukovič, Milan
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GRAPHICS processing units , *PLANAR motion , *QUANTUM computing , *GEOLOGICAL statistics , *ALGORITHMS - Abstract
The present research builds on a recently proposed spatial prediction method for discretized two-dimensional data, based on a suitably modified planar rotator (MPR) spin model from statistical physics. This approach maps the measured data onto interacting spins and, exploiting spatial correlations between them, which are similar to those present in geostatistical data, predicts the data at unmeasured locations. Due to the shortrange nature of the spin pair interactions in the MPR model, parallel implementation of the prediction algorithm on graphical processing units (GPUs) is a natural way of increasing its efficiency. In this work we study the effects of reduced computing precision as well as GPU-based hardware intrinsic functions on the speedup and accuracy of the MPR-based prediction and explore which aspects of the simulation can potentially benefit the most from the reduced precision. It is found that, particularly for massive data sets, a thoughtful precision setting of the GPU implementation can significantly increase the computational efficiency, while incurring little to no degradation in the prediction accuracy. [ABSTRACT FROM AUTHOR]
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- 2020
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33. One-step Stochastization Methods for Open Systems.
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Adam, Gh., Buša, J., Hnatič, M., Korolkova, Anna, and Kulyabov, Dmitry
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STOCHASTIC models , *VECTORS (Calculus) , *LANGEVIN equations , *FOKKER-Planck equation , *STOCHASTIC analysis - Abstract
In this paper, two approaches (combinatorial and operatorial) to the stochastization of the one-step processes are discussed for the closed and open version of the Lotka–Volterra model, respectively. [ABSTRACT FROM AUTHOR]
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- 2020
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34. Parallel Numerical Simulation of the Magnetic Moment Reversal within the φ0-Josephson Junction Spintronic Model.
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Adam, Gh., Buša, J., Hnatič, M., Panayotova, Stefani, Bashashin, Maxim, Zemlyanaya, Elena, Atanasova, Pavlina, Shukrinov, Yury, and Rahmonov, Ilhom
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COMPUTER simulation , *MAGNETIC moments , *SPINTRONICS , *MULTIFUNCTIONAL digital cameras , *SUPERCOMPUTERS - Abstract
The φ0-Josephson Dushanbe, Tajikistanjunction model with a coupling between the magnetic moment and the Josephson current in the "superconductor–ferromagnet–superconductor" system has been investigated. Numerical solution of the respective system of nonlinear differential equations is based on the two-stage Gauss–Legendre algorithm. For numerical simulation in a wide range of parameters which requires a significant computer time, a parallel MPI=C++ computer code has been developed. Results of numerical study of the magnetization effect depending on physical parameters, as well as results of methodological calculations demonstrating the efficiency of the parallel implementation, are presented. Calculations have been carried out at the Heterogeneous Platform "HybriLIT" and on the supercomputer "Govorun" of the Multifunctional Information and Computing Complex of the Laboratory of Information Technologies, JINR (Dubna). [ABSTRACT FROM AUTHOR]
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- 2020
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35. Numerical Investigation of the Water Vapour Diffusivity inside Homogeneous Porous Media.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Nikonov, Eduard, Popovičová, Mária, Korenkov, Vladimir, and Litavcová, Eva
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NUMERICAL analysis , *POROUS materials , *MOLECULAR dynamics , *THERMAL diffusivity , *ATMOSPHERIC water vapor - Abstract
This work is devoted to numerical investigation of diffusivity function for water vapour interaction with homogeneous porous media. Molecular dynamics simulation is used to determine the diffusivity function. Various approximations of diffusivity are applied for numerical solution of diffusion equation. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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36. Construction of Multivariate Interpolation Hermite Polynomials for Finite Element Method.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Chuluunbaatar, Galmandakh, Gusev, Alexander A., Chuluunbaatar, Ochbadrakh, Gerdt, Vladimir P., Vinitsky, Sergue I., Derbov, Vladimir L., Góźdź, Andrzej, Krassovitskiy, Pavel M., and Le Hai, Luong
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MULTIVARIATE analysis , *HERMITE polynomials , *FINITE element method , *POLYNOMIALS , *HELMHOLTZ equation - Abstract
A new algorithm for constructing multivariate interpolation Hermite polynomials in analytical form in a multidimensional hypercube is presented. These polynomials are determined from a specially constructed set of values of the polynomials themselves and their partial derivatives with continuous derivatives up to a given order on the boundaries of the finite elements. The effciency of the finite element schemes, algor thms and programs is demonstrated by solving the Helmholtz problem for a cube. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
37. Dynamics of a System of Two Connected Bodies Moving along a Circular Orbit around the Earth.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Gutnik, Sergey A., and Sarychev, Vasily A.
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EQUILIBRIUM , *GRAVITATION , *ALGEBRA software , *VECTOR analysis , *ALGEBRAIC equations - Abstract
Symbolic–numeric methods are used to investigate the dynamics of a system of two bodies connected by a spherical hinge. The system is assumed to move along a circular orbit under the action of gravitational torque. The equilibrium orientations of the two-body system are determined by the real roots of a system of 12 algebraic equations of the stationary motions. Attention is paid to the study of the conditions of existence of the equilibrium orientations of the system of two bodies refers to special cases when one of the principal axes of inertia of each of the two bodies coincides with either the normal of the orbital plane, the radius vector or the tangent to the orbit. Nine distinct solutions are found within an approach which uses the computer algebra method based on the algorithm for the construction of a Gröbner basis. [ABSTRACT FROM AUTHOR]
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- 2020
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38. Theoretical Basis of Nanobioelectronics.
- Author
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Adam, Gh., Buša, J., Hnatič, M., and Lakhno, Victor
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BIOELECTRONICS , *NANOELECTRONICS , *MINIATURE electronic equipment , *ELECTRONIC equipment , *SILICON compounds - Abstract
Several years ago, the modern silicon-based nanoelectronics came to the limits of its miniaturization. Its advancement into the range of 10 nm and less faces enormous challenges. A breakthrough in further miniaturization of electronic devices can be realized only on the basis of new approaches of which nanobioelectronics seems to be the most promising. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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39. Anomalous Scaling in the Kinematic Magnetohydrodynamic Turbulence.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Jurčišinová, Eva, Jurčišin, Marián, and Remecký, Richard
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MAGNETOHYDRODYNAMICS , *RENORMALIZATION (Physics) , *ANISOTROPY , *KOLMOGOROV complexity , *PERTURBATION theory - Abstract
The problem of the anomalous scaling in the kinematic magnetohydrodynamic turbulence is investigated using the field theoretic renormalization group method and the operator product expansion technique. The anomalous dimensions of all leading composite operators, which drive the anomalous scaling of the correlation functions of a weak passive magnetic field, are determined up to the second order of the perturbation theory (i.e., in the two-loop approximation in the field theoretic terminology) in the presence of a large scale anisotropy for physically the most interesting three-dimensional case. It is shown that the leading role in the anomalous scaling properties of the model is played by the anomalous dimensions of the composite operators near the isotropic shell, in accordance with the Kolmogorov's local isotropy restoration hypothesis. The importance of the two-loop corrections to the anomalous dimensions of the leading composite operators is demonstrated. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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40. An Approach to the Estimation of Dimensions from Static Images.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Jakab, František, Kainz, Ondrej, Michalko, Miroslav, and Petija, Rastislav
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CAMERAS , *HUMAN body , *QUANTITATIVE research , *MULTIDIMENSIONAL scaling , *ACCURACY - Abstract
The broad goal of this study is the estimation of dimensions of real-world multidimensional objects. The focus is on the human being and its dimensional parameters, primarily the height. The approach to the estimation of the height in a single camera environment is presented and is experimentally verified. The proposed method presumes that the distance from the optical device to the human body and its Vertical Field of View (VFOV) are known. The VFOV has to be calculated or acquired only once for a specific device. The accuracy of the proposed method is validated by a series of test scenarios including, e.g., statistical height measurements. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
41. Genetic Optimization of LDPC Codes to Improve the Correction of Burst Errors.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Broulím, Jan, Ayriyan, Alexander, and Grigorian, Hovik
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GENETIC correlations , *ERROR correction (Information theory) , *TELEVISION broadcasting , *SINGLE event effects , *HIGH performance computing - Abstract
Error correction plays a crucial role when transmitting data from the source to the destination through a noisy channel. It has found many applications in television broadcasting services, data transmission in radiation harsh environment (e. g. space probes or physical experiments) or memory storages influenced by Single Event Effects (SEE). Low Density Parity Check (LDPC) codes provide an important technique to correct these errors. The parameters of error correction depend both on the decoding algorithm and on the LDPC code given by the parity-check matrix. Therefore, a particular design of the paritycheck matrix is necessary. Moreover, with the development of high performance computing, the application of genetic optimization algorithms to design the parity-check matrices has been enabled. In this article, we present the application of the genetic optimization algorithm to produce error correcting codes with special properties, especially the burst types of errors. The results show the bounds of correction capabilities for various code lengths and various redundancies of LDPC codes. This is particularly useful when designing systems under the influence of noise combined with the application of the error correction codes. [ABSTRACT FROM AUTHOR]
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- 2020
- Full Text
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42. Event Reconstruction in the Tracking System of the CBM Experiment.
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Adam, Gh., Buša, J., Hnatič, M., and Friese, Volker
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BARYONS , *HEAVY-ion atom collisions , *DATA acquisition systems , *STREAMING audio , *RADIATION - Abstract
The Compressed Baryonic Matter experiment (CBM) will investigate strongly interacting matter at high net-baryon densities by measuring nucleus-nucleus collisions at the FAIR research centre in Darmstadt, Germany. Its ambitious aim is to measure at very high interaction rates, unprecedented in the field of experimental heavy-ion physics so far. This goal will be reached with fast and radiation-hard detectors, self-triggered read-out electronics and streaming data acquisition without any hardware trigger. Collision events will be reconstructed and selected in real-time exclusively in software. This puts severe requirements to the algorithms for event reconstruction and their implementation. We will discuss some facets of our approaches to event reconstruction in the main tracking device of CBM, the Silicon Tracking System, covering local reconstruction (cluster and hit finding) as well as track finding and event definition. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
43. Computational Model of Unsteady Hydromechanics of Large Amplitude Gerstner Waves.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Degtyarev, Alexander, Gankevich, Ivan, Kulabukhova, Nataliia, and Khramushin, Vasily
- Subjects
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COMPUTATIONAL linguistics , *FLUID mechanics , *SURFACE waves (Fluids) , *OCEAN waves , *ALTITUDES - Abstract
The computational experiments in the ship fluid mechanics involve the nonstationary interaction of a ship hull with wave surfaces that include the formation of vortices, surfaces of jet discontinuities, and discontinuities in the fluid under the influence of negative pressure. These physical phenomena occur not only near the ship hull, but also at a distance where the waves break as a result of the interference of the sea waves with waves reflected from the hull. In the study reported here we simulate the wave breaking and reflection near the ship hull. The problem reduces to determining the wave kinematics on the moving boundary of a ship hull and the free boundary of the computational domain. We build a grid of large particles having the form of a parallelepiped and, in the wave equation instead of the velocity field we integrate streams of fluid represented by functions as smooth as the wave surface elevation field. We assume that within the boundaries of the computational domain the waves do not disperse, i.e. their length and period stay the same. Under this assumption, we simulate trochoidal Gerstner waves of a particular period. This approach allows to simulate the wave breaking and reflection near the ship hull. The goal of the research is to develop a new method of taking the wave reflection into account in the ship motion simulations as an alternative to the classic method which uses added masses. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
44. Modelling Leaky Waves in Planar Dielectric Waveguides.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Ayryan, Edik, Divakov, Dmitry, Egorov, Alexandre, Lovetskiy, Konstantin, and Sevastianov, Leonid
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WAVEGUIDES , *STURM-Liouville equation , *MECHANICAL models , *MATHEMATICAL models , *DIELECTRIC devices - Abstract
Experimentally observed leaky modes of a dielectric waveguide are characterised by a weak tunnelling of the light through the waveguide and its long-time propagation along the waveguide. Traditional mathematical models of leaky waveguide modes meet some contradictions resolved using additional considerations. We propose a model of leaky modes in a waveguide free from the above contradictions, akin to the quantum mechanical model of the "pseudo-stable" Gamow-Siegert states. By separating variables, from the complete problem for plane inhomogeneous waves we obtain a non-self-adjoint Sturm-Liouville problem to determine the complex coefficient of the phase delay of the studied mode. The solution of the complete wave problem determines the propagation cone for the leaky mode of the waveguide, inside which there are no contradictions. Thus, solution is in qualitative agreement with experimental data. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
45. Universality Classes of the Hwa-Kardar Model with Turbulent Advection.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Antonov, Nikolay V., Gulitskiy, Nikolay M., Kakin, Polina I., and Serov, Vitaliy D.
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TURBULENT boundary layer , *RENORMALIZATION (Physics) , *STATISTICAL correlation , *DIFFERENTIAL equations , *ANISOTROPY - Abstract
Self-organized critical system in turbulent fluid environment is studied with the renormalization group analysis. The system is modelled by the anisotropic stochastic differential equation for a coarse-grained field proposed by Hwa and Kardar [Phys. Rev. Lett.62, 1813 (1989)]. The turbulent motion of the environment is described by the anisotropic d-dimensional velocity ensemble based on the one introduced by Avellaneda and Majda [Commun. Math. Phys. 131, 381 (1990)] and modified to include dependence on time (finite correlation time). Renormalization group analysis reveals three universality classes (types of critical behavior) differentiated by the parameters of the system. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
46. Renormalization Group in Non-Relativistic Quantum Statistics.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Honkonen, Juha, Komarova, M. V., Molotkov, Yu. G., Nalimov, M. Yu., and Zhavoronkov, Yu. A.
- Subjects
- *
RENORMALIZATION (Physics) , *NONRELATIVISTIC quantum mechanics , *GREEN'S functions , *FLUID velocity measurements , *STOCHASTIC models - Abstract
Dynamic behaviour of a boson gas near the condensation transition in the symmetric phase is analyzed with the use of an effective large-scale model derived from time-dependent Green functions at finite temperature. A renormalization-group analysis shows that the scaling exponents of critical dynamics of the effective multi-charge model coincide with those of the standard model A. The departure of this result from the description of the superfluid transition by either model E or F of the standard phenomenological stochastic models is corroborated by the analysis of a generalization of model F, which takes into account the effect of compressible fluid velocity. It is also shown that, contrary to the single-charge model A, there are several correction exponents in the effective model, which are calculated at the leading order of the ɛ= 4 − d expansion. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
47. Two-Species Reaction-Diffusion System: the Effect of Long-Range Spreading.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Birnšteinová, Šarlota, Hnatič, Michal, and Luivjanský, Tomáš
- Subjects
- *
REACTION-diffusion equations , *DIFFUSION , *POWER law (Mathematics) , *PARTICLE density (Nuclear chemistry) , *FEYNMAN integrals - Abstract
We study fluctuation effects in the two-species reaction-diffusion system A + B → Ø and A + A → (Ø, A). In contrast to the usually assumed ordinary short-range diffusion spreading of the reactants we consider anomalous diffusion due to microscopic long-range hops. In order to describe the latter, we employ the Lévy stochastic ensemble. The probability distribution for the Lévy flights decays in d dimensions with the distance r according to a power-law r−d−σ. For anomalous diffusion (including Lévy flights) the critical dimension dc = σ depends on the control parameter σ, 0 < σ ≤ 2. The model is studied in terms of the field theoretic approach based on the Feynman diagrammatic technique and perturbative renormalization group method. We demonstrate the ideas behind the B particle density calculation. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. Double-Folding Nucleus-Nucleus Optical Potential: Parallel MPI and OpenMP Implementations.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Bashashin, Maxim, Zemlyanaya, Elena, and Lukyanov, Konstantin
- Subjects
- *
COMPUTATIONAL learning theory , *NUCLEAR cross sections , *SCATTERING (Mathematics) , *MICROSCOPY , *TEST methods - Abstract
The computation of the real part of the nucleus-nucleus optical potential based on the microscopic double-folding model was implemented within both the MPI and OpenMP parallelising techniques. Test calculations of the total cross section of the 6He + 28Si scattering at the energy 50 A MeV show that both techniques provide significant comparable speedup of the calculations. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
49. Enabling Data Intensive Science on Supercomputers for High Energy Physics R&D Projects in HL-LHC Era.
- Author
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Adam, Gh., Buša, J., Hnatič, M., Klimentov, Alexei, Benjamin, Douglas, Di Girolamo, Alessandro, De, Kaushik, Elmsheuser, Johannes, Filipcic, Andrej, Kiryanov, Andrey, Oleynik, Danila, Wells, Jack C., Zarochentsev, Andrey, and Zhao, Xin
- Subjects
- *
SUPERCOMPUTERS , *PARTICLE physics , *DATA management , *PROTOTYPE (Linguistics) , *COMPUTER systems - Abstract
The ATLAS experiment at CERN's Large Hadron Collider uses theWorldwide LHC Computing Grid, the WLCG, for its distributed computing infrastructure. Through the workload management system PanDA and the distributed data management system Rucio, ATLAS provides seamless access to hundreds of WLCG grid and cloud based resources that are distributed worldwide, to thousands of physicists. PanDA annually processes more than an exabyte of data using an average of 350,000 distributed batch slots, to enable hundreds of new scientific results from ATLAS. However, the resources available to the experiment have been insufficient to meet ATLAS simulation needs over the past few years as the volume of data from the LHC has grown. The problem will be even more severe for the next LHC phases. High Luminosity LHC will be a multiexabyte challenge where the envisaged Storage and Compute needs are a factor 10 to 100 above the expected technology evolution. The High Energy Physics (HEP) community needs to evolve current computing and data organization models in order to introduce changes in the way it uses and manages the infrastructure, focused on optimizations to bring performance and efficiency not forgetting simplification of operations. In this paper we highlight recent R&D projects in HEP related to data lake prototype, federated data storage and data carousel. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
50. Coherence Dynamics of Two Interacting Bosonic Modes in a Thermal Environment.
- Author
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Adam, Gh., Buša, J., Hnatič, M., and Isar, Aurelian
- Subjects
- *
COHERENCE (Nuclear physics) , *RESERVOIRS , *PHOTONS , *MAGNETIC coupling , *ENTROPY - Abstract
We describe the time evolution of the quantum coherence in an open system consisting of two coupled bosonic modes embedded in a thermal reservoir. We discuss the influence of the environment in terms of the covariance matrix for initial squeezed thermal states. The coherence is quantified using the relative entropy as a measure, and its dynamics is studied in the framework of the theory of open systems based on completely positive quantum dynamical semigroups. We show that the evolution of the quantum coherence strongly depends on the initial state of the system (squeezing parameter and thermal photon numbers), the parameters characterizing the thermal reservoir (temperature and dissipation coefficient) and the intensity of the coupling between the two modes. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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