scholarly journals Modelling Reliability Characteristics of Technical Equipment of Local Area Computer Networks

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 955
Author(s):  
Vasyl Teslyuk ◽  
Andriy Sydor ◽  
Vincent Karovič ◽  
Olena Pavliuk ◽  
Iryna Kazymyra

Technical systems in the modern global world are rapidly evolving and improving. In most cases, these are large-scale multi-level systems and one of the problems that arises in the design process of such systems is to determine their reliability. Accordingly, in the paper, a mathematical model based on the Weibull distribution has been developed for determining a computer network reliability. In order to simplify calculating the reliability characteristics, the system is considered to be a hierarchical one, ramified to level 2, with bypass through the level. The developed model allows us to define the following parameters: the probability distribution of the count of working output elements, the availability function of the system, the duration of the system’s stay in each of its working states, and the duration of the system’s stay in the prescribed availability condition. The accuracy of the developed model is high. It can be used to determine the reliability parameters of the large, hierarchical, ramified systems. The research results of modelling a local area computer network are presented. In particular, we obtained the following best option for connecting workstations: 4 of them are connected to the main hub, and the rest (16) are connected to the second level hub, with a time to failure of 4818 h.

2021 ◽  
Vol 5 (2) ◽  
pp. 407-412
Author(s):  
Febrian Wahyu Christanto ◽  
April Firman Daru ◽  
Arif Kurniawan

Bandwidth problems are the most frequently encountered problems in sharing information traffic or internet access on computer networks. The factor that causes slow internet access is the large number of devices connected to the internet that are not matched by the availability of sufficient bandwidth and the lack of available bandwidth. This can be accommodated with bandwidth management methods. Bandwidth management in Mikotik uses several bandwidth sharing methods such as PCQ (Per Connection Queue), Queue Tree, and HTB (Hierchichal Token Bucket). This research uses 2 (two) bandwidth management methods, namely PCQ and Queue Tree because these methods can divide bandwidth automatically according to the number of active users and are more effective in sharing bandwidth based on Mikrotik. PCQ is a method aimed at optimizing QoS for large-scale internet networks where all queues are the same for all sub-streams, while Queue Tree is a method designed to carry out more complex queuing tasks for network traffic. The purpose of this research is to optimize the limited internet bandwidth so that it can be accessed by all users in the Local Area Network and automate the queue of devices connected to the network according to user needs so as to produce a more stable computer network performance using the network development method, namely NDLC. The results of the tests were carried out 10 times using a bandwidth of 10 Mbps which resulted in an average jitter of 1.64 ms, ping 36.8 ms, 2 Mbps throughput, and 0.1% packet loss so that the QoS of internet access was categorized as satisfactory. It is hoped that from this research the company will be able to save on internet access expenses by maximizing a small bandwidth without having to increase the existing bandwidth.  


2021 ◽  
pp. 174749302110064
Author(s):  
Hugh S Markus ◽  
Sheila Cristina Ouriques Martins

A year ago the World Stroke Organisation (WSO) highlighted the enormous global impact of the COVID-19 pandemic on stroke care. In this review we consider a year later where we are now, what the future holds, and what the long term effects of the pandemic will be on stroke. Stroke occurs in about 1.4% of patients hospitalised with COVID-19 infection, who show an excess of large vessel occlusion and increased mortality. Despite this association, stroke presentations fell dramatically during the pandemic, although emerging data suggests that total stroke mortality may have risen with increased stroke deaths at home and in care homes. Strategies and guidelines have been developed to adapt stroke services worldwide, and protect healthcare workers. Adaptations include increasing use of telemedicine for all aspects of stroke care. The pandemic is exacerbating already marked global inequalities in stroke incidence and mortality. Lastly the pandemic has had a major impact on stroke research and funding, although it has also emphasised the importnace of large scale collaborative research initiatives.


2021 ◽  
pp. 001316442110086
Author(s):  
Tenko Raykov ◽  
Natalja Menold ◽  
Jane Leer

Two- and three-level designs in educational and psychological research can involve entire populations of Level-3 and possibly Level-2 units, such as schools and educational districts nested within a given state, or neighborhoods and counties in a state. Such a design is of increasing relevance in empirical research owing to the growing popularity of large-scale studies in these and cognate disciplines. The present note discusses a readily applicable procedure for point-and-interval estimation of the proportions of second- and third-level variances in such multilevel settings, which may also be employed in model choice considerations regarding ensuing analyses for response variables of interest. The method is developed within the framework of the latent variable modeling methodology, is readily utilized with widely used software, and is illustrated with an example.


2013 ◽  
Vol 299 ◽  
pp. 130-134
Author(s):  
Li Wei ◽  
Da Zhi Deng

In recent years,china input in the construction of the network management is constantly increasing;information technology has improved continuously,but,making a variety of network security incidents occur frequently,due to the vulnerability of the computer network system inherent,a direct impact on national security and social and political stability. Because of the popularity of computers and large-scale development of the Internet, network security has been increasing as the theme. Reasonable safeguards against violations of resources; regular Internet user behavior and so on has been the public's expectations of future Internet. This paper described a stable method of getting telnet user’s account in development of network management based on telnet protocol.


2013 ◽  
Vol 397-400 ◽  
pp. 2090-2093
Author(s):  
An Hong Tian ◽  
Cheng Biao Fu

Due to the problem of network structure, security, redundant path in traditional network, this can be solved by Virtual Local Area Network (VLAN) technology. As the network laboratory in colleges and universities is not perfect because of high cost, a virtual simulation tools named Packet Tracer has been introduced to computer network experimental curriculum, this paper put forwards the detail design scheme by the example of VLAN with three switches, and provides the experiment and theoretical analysis and simulation verification .The practice has proved this method not only deepens students comprehension of network, but also cultivates the students' actual comprehensive ability.


2020 ◽  
Vol 11 (2) ◽  
pp. 17-24
Author(s):  
D. N. Vlasov ◽  
◽  
D. N. Zamaskin ◽  
O. O. Kaminsky ◽  
A. V. Kamorny ◽  
...  

The article discusses one of today’s challenges, namely, the decommissioning of nuclear power facilities. It summarizes the experience in the decommissioning of radioactive waste storage facilities belonging to RosRAO’s Murmansk department branch of the Northwest Territorial District providing detailed overview of pre-decommissioning activities, as well as the decommissioning operations themselves, relevant technology and technical equipment applied. Pre-decommissioning stage involved large-scale efforts (2011—2015) on accumulated RW identifi cation and its inventory taking, as well as a comprehensive engineering radiation survey. Decommissioning projects have been developed and approved, a state environmental examination has been carried out with a Sanitary and Epidemiological Statement on compliance with state sanitary and epidemiological rules and regulations issued by FMBA of Russia. The paper presents the practice of constructing some engineering structures to provide additional safety and security of RW storage facilities during their dismantlement. Particular attention was paid to the problems associated with the use of special equipment.


Author(s):  
E. Hänsler ◽  
G. K. McAuliffe ◽  
R. S. Wilkov

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