ASSESSMENT OF THE STRUCTURAL RELIABILITY OF TELECOMMUNICATION NETWORKS OF UNCERTAIN TOPOLOGY BASED ON IMITATION MODELING

2019 ◽  
Author(s):  
Nina Kniazieva ◽  
Alexey Nenov ◽  
Irina Kolumba
Keyword(s):  
Computer Model ◽  
Structural Reliability ◽  
Telecommunication Network ◽  
Structural Characteristics ◽  
Telecommunication Networks ◽  
Network Graph ◽  
Imitation Modeling ◽  
Average Total Number ◽  
Structural Methods

This article is devoted to the analysis of existing and the development of new approaches to assess the structural reliability of networks with an uncertain topology. Ensuring reliability in modern telecommunication networks is becoming an increasingly important issue in connection with the intensive development of these networks over the past decade. Existing structural methods for evaluating reliability are focused on applications for networks with a known structure. However, in cases where the network topology is constantly changing, these methods are of little use. Therefore, an approach is proposed for obtaining estimates of the structural reliability of telecommunication networks with an uncertain topology based on the use of basic structural characteristics alone. The developed method for assessing the reliability of telecommunication networks with an uncertain topology is presented, which provides the ability to determine: the total number of routes in the network with a certain number of nodes and branches; the number of routes per one connection, as well as the number of routes of rank no more than the allowable value that can be used for one connection. The upper limit of the structural reliability of individual connections are determined by the routes obtained for each connection), on the basis of which the structural reliability of a network with an uncertain topology is evaluated. A simulation computer model has been created for assessing the structural reliability of a telecommunication network with an uncertain topology, which consists of a computer model that empirically estimates the number of routes in various implementations of obtaining indicators of the structural reliability of communication between a pair of nodes and the entire network as a whole. A simulation experiment of computer modeling with given structural characteristics consists of a series of tests, in each of which a specific random implementation of a network graph is generated and all the routes existing in it are searched. The article presents the main functions and components of the developed software system, the figures show the modules and the basic algorithms of the model. Interfaces for inputting initial data and for outputting simulation results in the form of values ​​of the number of routes based on the results of simulation experiments and corresponding graphs are demonstrated. A  separate important issue that is solved in the simulation is the determination of a  sufficient number of tests in an experiment. The criterion for assessing this modeling parameter was the deviation dynamics of the average total number of routes of ranks 1 through 4 obtained in the tests.

scholarly journals The Development of Telecommunication Networks in Angola Republic

Telecom IT ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 1-9
Author(s):  
T. Nzinga ◽  
A. Koucheryavy
Keyword(s):  
System Analysis ◽  
Telecommunication Network ◽  
Telecommunication Networks ◽  
Practical Relevance ◽  
Research Subject ◽  
Development Method ◽  
The Republic

Research subject. The article is devoted to the analysis of the development of telecommunication net-works in the Republic of Angola and the prospects for their development Method. System analysis. Core results. Determination of promising areas of research in the development of communication net-works in terms of their creation in sparsely populated and hard-to-reach areas. Practical relevance. The results of the article can be used to modernize the telecommunication network of the Republic of Angola.

Interpreting Open- and Closed-Loop Transfer Relations Between Cardiorespiratory Parameters: Lessons Learned from a Computer Model of Beat-to-Beat Cardiovascular Regulation

1997 ◽  
Vol 36 (04/05) ◽  
pp. 237-240
Author(s):  
P. Hammer ◽  
D. Litvack ◽  
J. P. Saul
Keyword(s):  
Computer Model ◽  
Closed Loop ◽  
Computer Models ◽  
Cardiovascular Regulation ◽  
Cardiovascular Control ◽  
Lessons Learned ◽  
Multiple Systems ◽  
Response Characteristics ◽  
Similarities And Differences

Abstract:A computer model of cardiovascular control has been developed based on the response characteristics of cardiovascular control components derived from experiments in animals and humans. Results from the model were compared to those obtained experimentally in humans, and the similarities and differences were used to identify both the strengths and inadequacies of the concepts used to form the model. Findings were confirmatory of some concepts but contrary to some which are firmly held in the literature, indicating that understanding the complexity of cardiovascular control probably requires a combination of experiments and computer models which integrate multiple systems and allow for determination of sufficiency and necessity.

scholarly journals Influence of the Share of Renewable Energy Sources on the Level of Energy Security in EECCA Countries

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 903 ◽  
Author(s):  
Ivan Trifonov ◽  
Dmitry Trukhan ◽  
Yury Koshlich ◽  
Valeriy Prasolov ◽  
Beata Ślusarczyk
Keyword(s):  
Renewable Energy ◽  
Energy Security ◽  
Structural Characteristics ◽  
Renewable Energy Sources ◽  
Energy Resource ◽  
Energy Sources ◽  
Structural Content ◽  
High Degree

In this study we aimed to determine the extent to which changes in the share of renewable energy sources, their structural complex, and the level of energy security in Eastern Europe, Caucasus and Central Asia (EECCA) countries in the medium- and long-term are interconnected. The study was performed through modeling and determination of the structural characteristics of energy security in the countries. The methodology of the approach to modeling was based on solving the problem of nonlinear optimization by selecting a certain scenario. For the study, the data of EECCA countries were used. The ability of EECCA countries to benefit from long-term indirect and induced advantages of the transformation period depends on the extent to which their domestic supply chains facilitate the deployment of energy transformation and induced economic activity. This study provides an opportunity to assess the degree of influence of renewable energy sources on the level of energy security of countries in the context of energy resource diversification. The high degree of influence of renewable energy sources on energy security in the EECCA countries has been proven in the implementation of the developed scenarios for its increase. Energy security is growing. At the same time, its level depends not only on an increase in the share of renewable sources but also on the structure of energy resources complex of countries, and the development of various renewable energy sources. Therefore, today the EECCA countries are forced not only to increase the share of renewable energy sources but also to attach strategic importance to the structural content of their energy complex.

scholarly journals Structural characteristics of plant cell wall elucidated by solution-state 2D NMR spectroscopy with an optimized procedure

2020 ◽  
Vol 9 (1) ◽  
pp. 650-663
Author(s):  
Wanwan Wang ◽  
Jibao Cai ◽  
Zhenyu Xu ◽  
Yi Zhang ◽  
Fanchao Niu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Quantum Coherence ◽  
Nmr Spectra ◽  
Plant Cell Wall ◽  
Milling Time ◽  
Structural Characteristics ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Complete Representation

AbstractA method was developed for rapid qualitative determination of lignocellulose in the tobacco cell wall by utilizing 2D heteronuclear single quantum coherence NMR spectra (2D HSQC NMR). Traditional methods for analyzing the structure of lignocellulose involve many steps of separation and extraction, which is labor-intensive. In this work, the whole cell wall was milled and dissolved in deuterium solvent. The solvent dimethylsulfoxide (DMSO-d6) containing hexamethylphosphoramide (HMPA-d18) enhanced swelling of the sample and gave high-resolution spectra. The tobacco samples are ball milled at different ball milling times, and the state of the particles is observed through an electron microscope, and then the probability of the particles being less than 5 µm is counted. Through the comparison of the abundance and integration of the peak signals in the spectra under different transmittances, it was determined that when the milling time was 6 h, the quality of the NMR spectra was the best. The optimum conditions of characterizing tobacco structure were DMSO-d6/HMPA-d18 solution and 6 h milling time. Under these conditions, complete representation of the structure of lignocellulose and simplified process could be achieved.

Monte Carlo Simulation of Texture and Microstructure Transformation during Annealing of Steel

2007 ◽  
Vol 129 ◽  
pp. 83-87
Author(s):  
Hua Long Li ◽  
Jong Tae Park ◽  
Jerzy A. Szpunar
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Grain Boundary ◽  
Computer Model ◽  
Graphical Representation ◽  
Structural Characteristics ◽  
Polycrystalline Materials ◽  
Virtual Experiments ◽  
Grain Boundary Character ◽  
Simulation Based

Controlling texture and microstructure evolution during annealing processes is very important for optimizing properties of steels. Theories used to explain annealing processes are complicated and always case dependent. An recently developed Monte Carlo simulation based model offers an effective tool for studying annealing process and can be used to verify the arbitrarily defined theories that govern such processes. The computer model takes Orientation Image Microscope (OIM) measurements as an input. The abundant information contained in OIM measurement allows the computer model to incorporate many structural characteristics of polycrystalline materials such as, texture, grain boundary character, grain shape and size, phase composition, chemical composition, stored elastic energy, and the residual stress. The outputs include various texture functions, grain boundary and grain size statistics that can be verified by experimental results. Graphical representation allows us to perform virtual experiments to monitor each step of the structural transformation. An example of applying this simulation to Si steel is given.

An Analysis of Conventional and Self-Aligned four Terminal Resistor Structures for The Determination of The Contact Resistivity from End Resistance Measurements

1986 ◽  
Vol 71 ◽  
Author(s):  
I. Suni ◽  
M. Finetti ◽  
K. Grahn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Model ◽  
Contact Resistivity ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Model Based ◽  
A Value ◽  
And Diffusion

AbstractA computer model based on the finite element method has been applied to evaluate the effect of the parasitic area between contact and diffusion edges on end resistance measurements in four terminal Kelvin resistor structures. The model is then applied to Al/Ti/n+ Si contacts and a value of contact resistivity of Qc = 1.8×10−7.Ωcm2 is derived. For comparison, the use of a self-aligned structure to avoid parasitic effects is presented and the first experimental results obtained on Al/Ti/n+Si and Al/CoSi2/n+Si contacts are shown and discussed.

THE METHOD OF ESTIMATION FRACTAL DIMENSION OF THE TELECOMMUNICATION NETWORK

2021 ◽  
Author(s):  
Ф.Х. НАХЛИ ◽  
А.И. ПАРАМОНОВ
Keyword(s):  
Fractal Dimension ◽  
Comparative Analysis ◽  
Telecommunication Network ◽  
Shortest Paths ◽  
Network Connectivity ◽  
Telecommunication Networks ◽  
New Method ◽  
Topological Properties

Анализируется фрактальная размерность (ФР) сети связи и ее использование для исследования и планирования сетей связи. Рассматривается применение метода «выращивания кластера» для оценки ФР и предлагается новый метод определения ФР сети, основанный на оценивании связности сети путем поиска кратчайших путей. Показано, что оценка ФР сети является дополнительной характеристикой, отражающей топологические свойства сети. Дается сравнительный анализ предложенного метода и «выращивания кластера». Полученные результаты позволяют выбрать метод и получить оценки ФР сети в зависимости от ее особенностей. The paper analyzes the fractal dimension of the network and its use for telecommunication networks research and planning. The analysis of the "cluster growing" method for assessing the fractal dimension is given and a new method for assessing the fractal dimensionof anetwork is proposed, based onassessing the network connectivity by finding the shortest paths. The article shows that the assessment of the fractal dimension of the network is an additional characteristic that reflects the topological properties of the network. Comparative analysis of the proposed method and "cluster growing" is given. The results obtained make it possible to select a method and obtain estimates of the fractal dimension of the network, depending on its features.

Influence of Human Error on Structural Reliability

2017 ◽  
Author(s):  
Eric Brehm ◽  
Robert Hertle ◽  
Markus Wetzel
Keyword(s):  
Human Error ◽  
Structural Reliability ◽  
Failure Modes ◽  
Structural Model ◽  
Limit State ◽  
Design Procedure ◽  
Material Strength ◽  
Limit States ◽  
The Impact

In common structural design, random variables, such as material strength or loads, are represented by fixed numbers defined in design codes. This is also referred to as deterministic design. Addressing the random character of these variables directly, the probabilistic design procedure allows the determination of the probability of exceeding a defined limit state. This probability is referred to as failure probability. From there, the structural reliability, representing the survival probability, can be determined. Structural reliability thus is a property of a structure or structural member, depending on the relevant limit states, failure modes and basic variables. This is the basis for the determination of partial safety factors which are, for sake of a simpler design, applied within deterministic design procedures. In addition to the basic variables in terms of material and loads, further basic variables representing the structural model have to be considered. These depend strongly on the experience of the design engineer and the level of detailing of the model. However, in the clear majority of cases [1] failure does not occur due to unexpectedly high or low values of loads or material strength. The most common reasons for failure are human errors in design and execution. This paper will provide practical examples of original designs affected by human error and will assess the impact on structural reliability.

scholarly journals SIMULATION TESTS OF EXTINGUISHING PROCESS USING MIST NOZZLES WITH APPLICATION OF HYBRID FIRE MODEL

2016 ◽  
Vol 22 (4) ◽  
pp. 573-583 ◽  
Author(s):  
Jerzy GAŁAJ ◽  
Marek KONECKI ◽  
Ritoldas ŠUKYS
Keyword(s):  
Heat Flux ◽  
Computer Model ◽  
Input Data ◽  
Elementary Cell ◽  
Characteristic Parameters ◽  
Computational Cell ◽  
Fire Model ◽  
Fire Extinguishing ◽  
Unique Approach

The article presents a computer model of the fire extinguishing process using mist nozzles. A previously developed hybrid fire model was used for this purpose. Assumptions and relationships were given to represent a math­ematical model of extinguishing process, which comprises a unique approach to the determination of sprinkling area in an elementary cell of field fire model. A description of simulation tests of the model was given for several different input data, differing by mean diameters of droplets. This enabled a study of their effects on such output parameters as received heat flux, temperature and rate of its growth. For one selected computational cell located on the axis of the nozzle at floor level having the coordinates [10, 10, 1], the obtained results were presented in the form of heat flux and temperature. To simplify the analysis, characteristic parameters of particular curves were listed in the table. Conclusions formulated on the basis of results obtained during tests were specified at the end of work. They confirmed the expected regularity assuming that the extinguishing process was more effective in the case of droplets of a smaller diameter and greater sprinkling intensity. This allows assessing the degree, to which these stream parameters affect the extinguishing effectiveness.

scholarly journals Cooperative Problem Solving in Telecommunication Network

2013 ◽  
Vol 4 (3) ◽  
pp. 388-392
Author(s):  
Shanu K Rakesh ◽  
Bharat Choudhary ◽  
Rachna Sandhu
Keyword(s):  
Communication Network ◽  
Problem Solving ◽  
Distributed Control ◽  
Communication Networks ◽  
Foraging Behaviour ◽  
Telecommunication Network ◽  
Telecommunication Networks ◽  
Control Problems ◽  
Engineering Systems ◽  
Biologically Inspired

Swarm intelligence, as demonstrated by natural biological swarms, has numerous powerful properties desirable in many engineering systems, such as telecommunication. Communication network management is becoming increasingly difficult  due to the increasing size, rapidly changing topology, and complexity of communication networks. This paper describes  how biologically-inspired agents can be used to solve control problems in telecommunications. These agents, inspired by the foraging behaviour of ants, exhibit the desirable characteristics of simplicity of action and interaction. The colle ction of agents, or swarm system, deals only with local knowledge and exhibits a form of distributed control with agent communication effected through the environment. In this paper we explore the application of ant-like agents to the problem of routing in telecommunication networks.

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