This scientific paper explores the operation of a multiprocessor task servicing system. Tasks are received into the system at random intervals and are characterized by several stochastic parameters, ...including the number of processors required for their execution, the maximum allowable busy time for these processors, and the permissible waiting time in the task queue. The organization of task servicing in this system follows a first-in, first-out (FIFO) approach, ensuring uninterrupted processing. The key servicing process involves periodically selecting the first task in the queue and assessing its feasibility for immediate execution. If the task meets the necessary criteria, it is dispatched for processing. This process continues iteratively until a task is found, the parameters of which prevent immediate servicing. It is important to note that tasks in the queue have a limited window of time within which they can be serviced; otherwise, they may exit the system without service.
This paper focuses on systems characterized by exponential distributions for random variables related to task arrivals, servicing times, and waiting restrictions. A system of equations is derived that describes the system’s steady-state behavior. These equations enable the calculation of probabilities associated with the system’s various states. Additionally, the paper provides insights into the probability distributions of virtual waiting times for tasks that arrive in the system at any given moment.
African swine fever virus (ASFV) can accumulate and survive in leeches for a long time. The reasons for the survival of ASFV in leeches are not entirely clear. Here, we elucidate the virus survival ...pathway in infected leeches. One of the questions reported previously is addressed in this article. How the virus concentration in the body of the leech is equal to or higher than in the water infected with ASFV? Examination of blood swallowed by leeches reveals that the blood cells retain their morphological characteristics for several weeks. It can explain the long-term persistence of the high levels of ASFV in the leeches that ingested ASFV-infected pig blood. qRT-PCR assay showed the transcription of ASFV genes in infected leeches. However, the infectious particles of the virus measured by HADU haven’t increased. Quantitative studies of the ASFV revealed a high content of both viral genes and infectious particles in the skin of leeches compared with other body parts. Electron microscopy analysis revealed the ability of the ASFV to effectively bind to the skin surface of the leeches, which explained the high concentrations of ASFV in the leeches’ skin. A significant difference in the transcriptional activity between early and late viral genes indicates that the virus entered the initial stage of replication, but for some reason failed to complete it, which is typical of abortive infections.
•Leeches can play an important role in the ecology of ASFV.•ASF virus can accumulate in the skin of the Hirudo medicinalis through absorption.•Virus survives for a long time in the tissues of the Hirudo medicinalis.•ASFV can produce abortive infection in the tissues of the Hirudo medicinalis.
National Research and Education Networks (NRENs) are pivotal in modern research and education, providing a dynamic ecosystem for academic and scientific communities. These networks form the backbone ...for crucial infrastructures and services, propelling research, education, and innovation. This article explores the role of monitoring and advanced emulation in enhancing NREN performance. The experiences of ASNET-AM, the Armenian NREN, in leveraging these techniques are presented, highlighting the benefits and challenges.
In this paper, we propose the use of 2D pre-defined convolutional layers based on parabolic and hyperbolic Partial Differential Equations (PDEs) to learn low-level abstractions. We demonstrate their ...effectiveness by adding them on top of ResNet, ResNext, DenseNet, and VGG architectures and performing numerical experiments on the CIFAR-10 dataset.
We study the classical 1D Heisenberg spin glasses in the framework of nearest-neighboring model. Based on the Hamilton equations we obtained the system of recurrence equations which allows to perform ...node-by-node calculations of a spin-chain. It is shown that calculations from the first principles of classical mechanics lead to ℕℙ hard problem, that however in the limit of the statistical equilibrium can be calculated by ℙ algorithm. For the partition function of the ensemble a new representation is offered in the form of one-dimensional integral of spin-chains’ energy distribution.
In the current paper the numerical simulation results for parallel (decoupled) operation of SASE1 and SASE3 undulator sections of European XFEL are presented. The study was based on the idea of ...betatron switcher implementation. It was shown that it is possible to avoid energy spread growth in SASE1 and to reach the saturation in SASE3 in desirable range of radiation wavelengths by a trajectory kick before SASE1 and its correction before SASE3.
The application of reclamation measures to improve the state and increase the fertility of irrigated secondary saline and solonetzic meadow-brown soils (Anthrosols) of the Ararat Plain is ...substantiated. The indices of soil fertility determining the yield of the main crops were studied. According to monitoring studies, the economic efficiency of different crops was estimated. It is shown that the income from the yield of winter wheat, alfalfa, vegetables, and melons on the soils without salinization and alkalization increases by 2, 2.7, 4.2, and 13.7 times, respectively. The following reclamation measures to improve the ameliorative state of the studied soils are proposed: cultivation of alfalfa, application of gypsum in doses of 12–64 t/ha, and washing of the soil with irrigation water; the amount of water in this case has to be increased by 1.5 times in comparison with the norm. The economic assessment of the proposed reclamation measures is given. The obtained results can be implemented in the farms of Armavir and Ararat regions of Armenia.
Under antiplane deformation, the problem of the contact interaction of a thin infinite stringer of finite width with an elastic 3D wedge-shaped body of an arbitrary opening angle is considered. It is ...assumed that one face of the wedge is rigidly clamped while a stringer is attached to the other face, which does not extend to the top of the wedge. The deformation of a stringer is described by the well-known Melan model for antiplane deformation, and the stress–strain state of an elastic wedge is described by the equations of elasticity theory. Two formulations of the contact problem are discussed according to the two models of stringer deformation. In the first formulation, as usual, external tangential loads and concentrated forces acting on the stringer are specified, and it is required to determine the tangential contact stresses arising under the stringer and axial stresses in it. In the second formulation of the problem, the elastic displacements of the stringer points are predetermined; it is required to determine the force factors acting on the stringer that provide the specified mode of elastic displacements. Using the Mellin integral transform, solving the contact problem under consideration is reduced to solving a singular integral equation (SIE) with a kernel in the form of a sum of the Cauchy kernel and a regular kernel in the first formulation and to solving a Fredholm integral equation (IE) of the first kind with a symmetric logarithmic kernel in the second formulation. The solution of both integral equations is constructed by the method of mechanical quadratures, based on the use of well-known Gauss-type quadrature formulas for calculating singular integrals at Chebyshev nodes, as well as Gauss-type quadrature formulas for calculating integrals containing logarithmic and signum regular kernels. Ultimately, solving the equation is reduced to solving a finite system of linear algebraic equations (SLAE). A numerical analysis of the problem was carried out, and regularities in the change in the main mechanical quantities of the problem were revealed in a quite wide range of changes in the characteristic physical and geometric parameters.
The interaction of groove binding compounds — peptide antibiotic (polyamide) netropsin and fluorescent dye (bisbenzimidazole) Hoechst 33258 — with the double-stranded DNA and synthetic ...double-stranded polynucleotide poly(rA)-poly(rU) has been studied by spectrophotometry. Absorption spectra of these ligand complexes with nucleic acids have been obtained. Spectral changes at the complexation of individual ligands with the mentioned nucleic acids reveal the similarity of binding of each of these ligands with both DNA and RNA. Based on the spectroscopic measurements, the binding parameters of netropsin and Hoechst 33258 binding to DNA and poly(rA)-poly(rU) – K and n, as well as the thermodynamic parameters ΔS, ΔG, and ΔH have been determined. It was found that the binding of Hoechst 33258 to both nucleic acids is accompanied by a positive change in enthalpy, while in the case of netropsin the change in enthalpy is negative. Moreover, the contribution of entropy to the formation of the complexes is more pronounced in the case of Hoechst 33258.
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