scholarly journals Analysis of simulation model application to forecast the railway workers failures

2007 ◽  
Vol 17 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Milan Markovic ◽  
Milos Ivic ◽  
Norbert Pavlovic ◽  
Sladjana Jankovic

In this paper the idea of treating the operational service workers as the elements of technique systems is suggested and the renewal theory is used to forecast the number of accidents caused by human factor. The analytical model is presented and limitations for its application are quoted. Furthermore, the simulation model is developed and the conditions for its use are given. The model observes each worker separately and establishes the exact time of arisen failures, the number of failures at some moment t, time tn, to the nth failure, inconsistency of failure number and total number of failures of the observed population. The model is tested on the sample of 348 engine drivers in PE "Serbian Railways" who have made at leas one accident, in order to research the parameters necessary for using the renewal theory and simulation. .

2006 ◽  
Vol 3 (3) ◽  
pp. 819-857
Author(s):  
N. B. Yenigül ◽  
A.T. Hendsbergen ◽  
A. M. M. Elfeki ◽  
F. M. Dekking

Abstract. Contaminant leaks released from landfills are a significant threat to groundwater quality. The groundwater detection monitoring systems installed in the vicinity of such facilities are vital. In this study the detection probability of a contaminant plume released from a landfill has been investigated by means of both a simulation and an analytical model for both homogeneous and heterogeneous aquifer conditions. The results of the two models are compared for homogeneous aquifer conditions to illustrate the errors that might be encountered with the simulation model. For heterogeneous aquifer conditions contaminant transport is modelled by an analytical model using effective (macro) dispersivities. The results of the analysis show that the simulation model gives the concentration values correctly over most of the plume length for homogeneous aquifer conditions, and that the detection probability of a contaminant plume at given monitoring well locations match quite well. For heterogeneous aquifer conditions the approximating analytical model based on effective (macro) dispersivities yields the average concentration distribution satisfactorily. However, it is insufficient in monitoring system design since the discrepancy between the detection probabilities of contaminant plumes at given monitoring well locations computed by the two models is significant, particularly with high dispersivity and heterogeneity.


2012 ◽  
Vol 249-250 ◽  
pp. 118-125
Author(s):  
Oleg Sazhin

An analytical model of the flow sensor of thermal type is developed. The results of the model application are used to develop a flow microsensor of thermal type with optimal functional characteristics. The technology of microsensor manufacturing is provided. The prototype of the microsensor suitable for use in the mass air flow meter is created. The basic characteristics of the microsensor are presented.


2004 ◽  
Vol 130 (6) ◽  
pp. 511-519 ◽  
Author(s):  
F. Dechmi ◽  
E. Playán ◽  
J. Cavero ◽  
A. Martínez-Cob ◽  
J. M. Faci

2019 ◽  
Vol 18 (6) ◽  
pp. 1462-1490
Author(s):  
Evgeniy Minakov ◽  
Boris Sokolov ◽  
Sergey Shaldaev ◽  
Maksim Aleksandrov

A development of work to combat the asteroid hazard requires construction and study of areas of outer space in which moving spacecraft-interceptors can affect asteroids. In this paper, such areas are called attack lines, the spatio-temporal characteristics of which depend on the parameters of the asteroid’s orbits and the phase coordinates of the nodal points. At these points the trajectory intersects the asteroids and the orbital planes of the spacecraft-interceptors. In the case of the impact of spacecraft-interceptors on asteroids at nodal points, the study of the spatio-temporal characteristics of the lines of attack, taking into account restrictions on the relative speeds between asteroids and spacecraft-interceptors, is of particular importance. Building and analyzing the corresponding zones of reverse reach are suggested. In the article, the developed models include a simulation model, using which random angles between the projections of the velocity vectors of asteroids on a plane of the orbits of spacecraft-interceptors and the current directions on the hodographs of their velocity vectors at nodal points, as well as an analytical model for estimating the spatio-temporal characteristics of boundaries are simulated attacks of asteroids, including: the radii of their external and internal boundaries for certain values of the latitude arguments and arrival time of spacecraft-interceptors at modal points. Testing these models and the corresponding characteristics of the attack lines were carries out during computational experiments on two cyclic modeling of the angles between the projections of the velocity vectors of asteroids on the plane of the orbits of interceptor spacecraft and the current directions on the hodographs of their velocity vectors at nodal points. The results obtained made it possible to verify and validate the developed models, on the basis of which a conclusion was drawn about the required degree of their applicability. In the paper also a procedure for estimating the parameters of attack lines, depending on the values of the arguments of the latitudes of interceptor spacecraft and their altitudes above the Earth's surface is proposed. At the same time, an approach is substantiated for estimating the spatio-temporal characteristics of the boundaries of attack of asteroids by spacecraft-interceptors for any inside the planar parameters of their orbits.


2019 ◽  
Vol 18 (5) ◽  
pp. 1000-1013 ◽  
Author(s):  
Sami Khairy ◽  
Mengqi Han ◽  
Lin X. Cai ◽  
Yu Cheng ◽  
Zhu Han

Author(s):  
S.V. Lienkov ◽  
V.M. Dzhulij ◽  
A.V. Selyukov ◽  
V.S. Orlenko ◽  
A.V. Atamaniuk

The article proposes an approach to defining a security model for the dissemination of prohibited information in information and telecommunication networks. The most effective prediction of the spread of the prohibited information threat is carried out by modeling this process. Information and telecommunication networks are large-scale networks with an ever-growing number of subscribers. With the rapid growth in the number of ITKS users, there are problems of information security and information protection in them. The analysis of information security problems proved that apart from the problems associated with the use of the global Internet as a distributed information and telecommunication system, it is well known and can be solved, there is a poorly studied problem of prohibited content. Creation of models and algorithms for the spread of the threat of prohibited information is one of the key approaches to solving this problem. The analysis of publications on this topic shows that existing solutions are ineffective. Usually, when modeling the propagation of a threat of prohibited information, the ITKS topology (the network model is a fully connected graph) is not taken into account. When modeling the threat of the spread of prohibited information, it is important to have a topology that reflects the structure of connections in a real network, as well as to use an adequate model of information interaction between nodes. Another important problem is the large-scale ITCS, which makes it difficult to obtain data from the simulation model in a reasonable time. The solution to this problem is to create an analytical model of the threat of the spread of prohibited information in the ITCS. An algorithm has been developed for the implementation of TSPI (threat of the spread of prohibited information) in the ITKS, based on the nature of the processes occurring in real conditions. The simulation model of TSPI in ITKS has been proposed, which takes into account the topological characteristics of the network, as well as the features of information interaction of subscribers as man-machine systems. With its help, experiments have been carried out, the results of which have shown the dependence of the implementation of the RFID on the topological vulnerability of the network. An analytical model of the TSPI has been developed, taking into account the topological vulnerability of the network. The relevance of the results of the analytical solution was confirmed by a series of experiments on the topology of a real network using simulation modeling. In this case, the error for the protection process was no more than 10%, for the attack process - no more than 15%.


2008 ◽  
Vol 7 (6) ◽  
pp. 2340-2349 ◽  
Author(s):  
Xinhua Ling ◽  
Yu Cheng ◽  
J.W. Mark ◽  
Xuemin Shen

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