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.
Hip osteoarthritis (OA) is difficult to treat. Steroid injections reduce pain with short duration. With widespread adoption of office-based, image-guided injections, hyaluronic acid is a potentially ...relevant therapy. In the largest clinical trial to-date, we compared safety/efficacy of a single, 6-mL image-guided injection of hylan G-F 20 to saline in painful hip OA.
357 patients were enrolled in a multicenter, double-blind, randomized saline placebo- controlled trial. Subjects were ≥35 years of age, with painful (Western Ontario and McMaster Universities Osteoarthritis Index WOMAC-A1:5.0–8.0; numeric rating scale NRS: 0–10) mild-to-moderate hip OA (Kellgren–Lawrence grade II/III) and minimal contralateral hip pain (WOMAC-A1 < 4). Outcome measures included “pain on walking” (WOMAC-A1 and -A), Patient Global Self-Assessment (PTGA), WOMAC-A1 responder rate (+≥2 points on NRS), and adverse events (AEs) over 26 weeks.
357 patients (hylan G-F 20 single:182; saline:175) were enrolled. Both groups demonstrated significant pain improvement from baseline over 26 weeks (P < 0.0001); saline-induced pain reduction was a remarkable 35%. WOMAC-A and PTGA scores also significantly improved (P < 0.0001). No statistically significant difference was observed between groups in WOMAC-A1 scores (hylan G-F 20 single:−2.19 ± 0.16; saline:−2.26 ± 0.17) or WOMAC-A1 responders (41–52%). Treatment-related AE rates at target hip were similar (hylan G-F 20 single:23 patients 12.8%; saline:12 7.0%). Posthoc analysis found, despite protocol requirements, many patients had psychological (31%) or potential neuropathic pain (27.5%) conditions.
A single 6-mL hylan G-F 20 injection or saline for painful hip OA resulted in similar, statistically significant/clinically relevant pain and function improvements up to 6 months following injection; no differences between hylan G-F 20 and saline placebo were observed.
The treatment of porphyry copper ores which are considered an important source of non-ferrous and precious metals requires the development of high-efficient technologies for metal extraction ensuring ...a low impact on the environment. The goal of the present work was to study the feasibility of a biohydrometallurgical approach for the processing of Kajaran porphyry copper-molybdenum ore as no attempt was done previously for microbiological processing of the mentioned ore. Sulfide and oxide ore samples used for bioleaching tests contained 0.63 and 0.77% copper, 1.81 and 1.55% iron, and 0.14 and 0.023% molybdenum, respectively. The experiments were carried out in 250 ml flasks under shaking conditions. Indigenous and adapted bacterial consortia 'Kashen' and 'Kavart' were used for bioleaching of ore samples. The objectives of the study were to investigate the influence of particle size (PS), pulp density (PD), and adaptation of the bacterial cultures to the process of copper extraction. The composition of feed material and leaching residues from bioleaching experiments were characterized by geochemical, mineralogical, and particle analyses. As a result, nearly complete bioleaching of the sulfide and oxide ores could be achieved after the optimization of the experiments. The particle analyses showed an enhanced liberation of chalcopyrite particles out of the intergrown ore under bioleaching conditions compared to the abiotic controls and hence an improved Cu solubilization under bioleaching conditions.
Acidophilic chemolithotrophic microorganisms (CMs) are widely used for bioleaching of mineral resources. However, the growth of bacteria and their leaching activity are often inhibited (restricted) ...by organic components, e.g. lysates and exudates. The aims of this study were to examine the extent of cell lysis (CLs) inhibition on acidophilic microorganisms and to identify microorganisms that can utilize CLs products and eliminate their inhibition effect on acidophilic microorganisms. Specifically, it was revealed that Acidithiobacillus caldus was severely inhibited at 5% CLs products, whereas A. ferrooxidans and Leptospirillum ferriphilum are severely inhibited at 20%. It has been found that strains RBA and RBB of heterotrophic bacteria, isolated from anaerobic sludge, can biodegrade CLs products and when co-cultured with A. ferrooxidans, they can alleviate the toxic effect of CLs products under low pH (2-3). It has been shown that besides CLs, isolated strains can grow on glucose, glycerol, yeast extract, citric acid, and tryptone soya broth with an optimum temperature of 35°C and a pH of 3. The strains showed the ability to reduce ferric ions to ferrous ions when glycerol was used as a substrate after 2 days under both aerobic and anaerobic conditions. On the basis of morphophysiological and molecular biological studies, the isolated strains RBA and RBB were identified as Acidocella spp.
Software-defined radio (SDR)-based cognitive communication radio systems are very popular at present, and there have been many investigations on this topic. This paper proposes a new type of ...cognitive radio transceiver (TRX) that can detect, recognize, and analyze input signals in real-time with minimal data loss. New hardware is designed and manufactured that combines a transmitter and a receiver in a dedicated integrated circuit. For data processing, a field-programmable gate array (FPGA) is used. For each integrated hardware block, appropriate software modules are developed to construct a complex adaptive radiocommunication system as a radio modem that can be configured as a transceiver or repeater. The source coder, channel coder, modulator, spectrum monitoring module, spectrum analyzer, channelizer, symbol rate detector, modulator, modulation type recognition module, demodulator, channel decoder and source decoder are all developed as software modules.
A composition analysis of KASCADE air shower data is performed by means of unfolding the two-dimensional frequency spectrum of electron and muon numbers. Aim of the analysis is the determination of ...energy spectra for elemental groups representing the chemical composition of primary cosmic rays. Since such an analysis depends crucially on simulations of air showers the two different hadronic interaction models QGSJet and SIBYLL are used for their generation. The resulting primary energy spectra show that the knee in the all particle spectrum is due to a steepening of the spectra of light elements but, also, that neither of the two simulation sets is able to describe the measured data consistently over the whole energy range with discrepancies appearing in different energy regions.
The review presents the history of the creation and work of the Scientific Council “Cybernetics” (SCC)—the center for development of cybernetics in the USSR and Russia. The Council’s activity is ...covered as a structure that coordinates scientific and technical activity in cybernetics in the country via a system of sections: about 16 public and professional bodies involving thousands of specialists. Brief information about the sections is given. The chronology of development of the SCC is discussed, in particular, information about its chairmen, starting with the renowned organizer of research and development, Academician and Admiral Axel Ivanovich Berg and the following academicians: B.N. Petrov, O.M. Belotserkovsky, A.P. Ershov, E.P. Velikhov, B.V. Bunkin, and Yu.I. Zhuravlev. The SCC’s publishing activity is briefly reviewed. The second function, built into the SCC from its onset, is as a research institute conducting its own research on the most pressing scientific problems insufficiently covered by existing structures. Several main areas of research by the SCC itself and its successor, the Axel Berg Institute of Cybernetics and Educational Computing of the Federal Research Center “Computer Science and Control” of the RAS: coding and transmission of information, economic cybernetics, aircraft control, supercomputers, digital technologies in education, mathematical logic and the theory of algorithms, pattern recognition and image analysis, mathematical methods of image analysis, theoretical physics, biomedical cybernetics, and ultrasound imaging. Another function of the SCC is considered: as an incubator of new academic industrially oriented structures and the fate of one of them—the Institute of Cybernetics Problems—is traced.
The history of lacustrine sedimentation in the Sevan depression is traced. The potential of using lacustrine sediments for the analysis of paleoclimate and neotectonic development of the region is ...shown. The long-term preservation of the lacustrine regime in the Sevan depression is mainly due to large lava flows that repeatedly create dams in the northwestern part of the depression. A coupled analysis of three dated sections of sediments near the coast of Lake Sevan (Dzknaget, Norashen, and Argichi) shows that the main factor determining the lake level fluctuations in the Holocene is the climate: the alternation of eras with varying moisture amounts. Transgression periods are characterized by the accumulation of shallow–lake and beach facies and regression periods are characterized by alluvial and subaerial technogenic (cultural layers) facies. Holocene sediments of Lake Sevan contain synchronous transgressions of the Subarctic, Atlantic and Sub-Atlantic periods and regressions of the Boreal and Subboreal periods. The transgression periods are associated with climate moistening and the development of tree–shrub vegetation in its watershed area, and the regressions correspond to epochs of a decrease in humidity and a reduction of this type of vegetation. The minimum lacustrine sedimentation rates are typical for beach facies that are remote from river mouths (0.1–0.3 mm/year), and the maximum values are typical for delta facies (0.7–1.5 mm/year). The results can be used to analyze and forecast long-term trends in the development of the natural environment in the watershed area of Lake Sevan and changes in its level.
•Prediction of irradiation embrittlement of Armenian RPV materials on the basis of surveillance data.•Selected materials from IAEA International Database on RPV materials were used for ...analysis.•Regulatory Guide predicts rather conservative the irradiation embrittlement of RPV steels.
The basic results of the Armenian RPV surveillance program are presented. A change in ΔTk – neutron fluence trend curve shape is observed at a fluence of more than 4×1020cm−2 for both base metal and weld.
The prediction of radiation embrittlement of Armenian RPV materials was performed on the basis of surveillance data and information from the IAEA International Database on RPV materials. Because the original weld surveillance data could not be used for the Armenian RPV weld embrittlement assessment, an analysis of selected data from the Database was carried out. Six welds and two base metals of WWER-440 steel with P and Cu contents similar to Armenian welds were selected and their embrittlement results were compared with the Russian Regulatory Guide prediction. It is demonstrated that the Guide corresponding to Af=24.64 (chemistry factor for Armenian RPV weld No. 4) predicts the irradiation embrittlement of the selected steels conservatively. According to the Guide prediction the Tk for weld No. 4 should not exceeded 145°C by 2016. It is also demonstrated that the Armenian base metal irradiation embrittlement is substantially less than the Guide prediction.
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