A model study of the 30-50 day oscillation In the tropical atmosphere

Using a global spectral model with wave-CISK formulation we have generated an eastward de which. Resembles the observed 30-50 day mode. This has a scale of global wave number one and two years structure in the vertical. It has the structure of a composite of Kelvin and Rossby waves. This composite system moves eastwards. We have also studied a linear two-level analytical model to understand the nonlinear spectral model response. In the linear as well as in the nonlinear spectral model, as we Increase the moisture availability factor the speeds of the waves decrease. In the linear model this speed is found to be independent of drag for all types of waves. In the nonlinear spectral model for a given drag there is a critical value of the moisture availability factor for which the wave becomes stationary and beyond which even shows westward propagation. Thus both moisture availability and nonlinearity appear to contribute to the slow eastward speed of the equatorial 30-50 day mode.

Analysis of the operational readiness of telecommunication networks

The article discusses telecommunication communication networks of various topologies. The definition of the operational readiness coefficient is given. The analysis of various networks of different topologies for the reliability of information transmission is carried out. Comparison of the reliability of the ring and radial topologies in terms of the operational availability factor is carried out.

Assessment reliability parameters of the DVB-T2 broadcasting station’s equipment with local content insertion

Local content modification provided to subscribers of the terrestrial digital television signal is necessary to provide the technical possibility of organizing inserts of local content signals, such as TV programs of regional broadcasters, as well as information on emergency situations. Broadcast multiplexes of federal TV programs are designed for use within the corresponding time zone (A, B, C, D, M). In each time zone, there are a number of regions, in each of which there are local TV and radio companies that produce local content that must be delivered to the subscribers of the whole subject. The task of embedding/modifying content at each remote transmitting station is performed by an inserter or local content insertion device (ETSI TS 102773). The reliability parameters of the restorable system for organizing terrestrial television broadcasting at a remote station with the content modification were calculated in this article. Tables and a graph of the broadcasting system states are presented, on the basis of which, systems of Kolmogorov differential equations are compiled. It was found that additional redundancy organized by connecting the output stream from the RX1 receiver directly to the transmitting device allows for a 2.5-fold increase in the average operating time between failures, as well as an increase in the availability factor by 5.26 percent. All calculations were performed using the SimInTech software package. The influence of automatic redundancy of the local content inserter and the transmitter on the occurrence of errors in the stream that affect the quality of the output signal is considered. The relationship between the availability factor and the components of the quality of service parameter – SAE, SDE and SIE is determined.

SIMULATION MODEL FOR RELIABILITY ESTIMATION OF NON-MAINTAINED RAILWAY TELECOMMUNICATION DEVICES

The paper presents a discrete-event model of non-maintained railway telecommunication equipment operation. The model developed in the AnyLogic environment allows to estimate the availability factor and specific quality indicator of such systems, as well as to predict time spent in various states. The presented model can be used both at the design and operation stage for the compliance assessment of telecommunication equipment parameters with the reliability requirements.

Availability of Trace Elements in Soil with Simulated Cadmium, Lead and Zinc Pollution

The research was based on a pot experiment in which the impact of increasing Cd, Zn and Pb doses on the content of available trace elements in soil was compared. Seven series of trials were designed: 1 (Cd), 2 (Pb), 3 (Zn), 4 (Cd + Pb), 5 (Cd + Zn), 6 (Pb + Zn), 7 (Cd + Pb + Zn). Aside from the control one (without the metals), three increasing levels of contamination were considered within each series. Mobile forms of trace elements (Cd, Pb, Zn, Fe, Mn, Cu, Ni, Co, and Cr) in soil were determined, in addition to which selected physicochemical soil properties—reaction (pH), salinity (EC), hydrolytic acidity (HAC), total exchange bases (TEB)—were identified while cation exchange capacity (CEC), base saturation (BS) and availability factor (AF) were calculated. The application of Cd and Pb to soil resulted in an increase in the share of potentially available forms of these metals in their total content. The availability factor (AF) in the pots polluted with these metals was higher than in the control, in the range 17.5–20.0% for Cd, and 62.8–71.5% for Pb. In turn, the share of Zn mobile forms was comparable in most experimental objects, oscillating around 30%. Moreover, addition to soil of Cd, Pb and Zn usually caused a significant decrease in the content of available forms of Fe, Mn and Cu, and resulted in significantly higher content of available forms of Cr in the soil.

Forecasting Price of Amazon Spot Instances Using Machine Learning

An auction-based cloud model is followed in the spot pricing mechanism, where the spot instances charge changes with time. The user is bound to pay for the time that is initially initiated. If the user terminates before the sessional hourly completion, then the customer will be billed on the entire hourly session. In case Amazon terminates the instance then the customer would not be billed for the partial hour. When the current spot price reduces to bid price without any notification the cloud provider terminates the spot instance, it is a big disadvantage to the time of the availability factor, which is highly important. Therefore, it is crucial for the bidder to forecast before engaging the bids for spot prices. This paper represents a technique to analyze and predict the spot prices for instances using machine learning. It also discusses implementation, explored factors in detail, and outcomes on numerous instances of Amazon Elastic Compute Cloud (EC2). This technique reduces efforts and errors for forecasting prices.

Semi-Markov analytical model for assessing the quality of the maintenance system and the state of electromechanical complexes

Analysis of basic research. In practice, the EMC reliability indicators, in particular the failure rate, are time-varying quantities. In view of this, it is necessary to determine such periodicity values and maintenance volumes that would ensure the EMC maximum availability factor. The most adequate mathematical model for analyzing the technical state of EMC can be obtained using the apparatus of the theory of semi-Markov processes (PMF), the basis of which is an oriented graph of the basic states and transitions (GSP) of EMC during operation, which allows to formulate maintenance and maintenance strategies, the content of a separate strategy is determined a specific set of options for all states of EMC.The purpose of the article. Construction and study of a mathematical model of the EMC operation process to determine the optimal intervals and maintenance and repair strategies.The main research material. The solution to the first problem includes: building a model for the operation of the EMC; the derivation of the calculated ratio for the availability factor as a function of the technical condition of the EMC and the service station; obtaining an analytical formula for calculating optimal maintenance intervals.The paper proposes a combination of indicators ranked by importance in the linear programming problem, where the transfer time, which is a function of the SRT parameters and the technical condition of the EMC, is selected as the objective function, and the remaining indicators (readiness level, complex operation costs, and others) are taken into account in the form of restrictions. The result of solving this problem is a set of maintenance and repair options at each step of the operation of the EMC, which comprise the content of the optimal maintenance and repair strategy.Conclusions. An analytical relationship was obtained on the basis of the semi-Markov model of the operation process that allows one to calculate the optimal conditions for ensuring the availability factor of the periodicity of maintenance, which makes it possible to control the unsteady operation of the EMC, to obtain the necessary technical and economic quality indicators to build an adaptive ACS with the technical state of the EMC.