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Queuing theory and virtual factory by using mathematical models
Myška, Martin ; Klimeš, Lubomír (referee) ; Mauder, Tomáš (advisor)
This thesis deals with the modelling of a production line. The topology of the line is based on the real production line of BOSCH DIESEL s.r.o. – Jihlava company. Simulations have been made using Matlab-Simulink-SimEvents software. The created model represents a pilot simulation of the manufacturing process. The model allows to set a deterministic or stochastic approach and use of an auxiliary worker for planning machine maintenances and finding the bottlenecks in the production. As a pilot version the model is simplified, e.g. the short breaks of operators are neglected. The simulation results and comparisons are described in detail later in this document. In order to bring the simulation closer to the real manufacturing process, future improvement options are mentioned.
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Optimization of Signalling Traffic in IMS Subsystem of NGN Networks
Nagy, Ľuboš ; Orgoň, Miloš (referee) ; Bezpalec, Pavel (referee) ; Novotný, Vít (advisor)
One of causes of increased latency service over the whole IMS network can be unbalanced SIP (Session Initiation Protocol) signalling traffic through CSCF (Call Session Control Function). This thesis is devoted to the proposal of weight-based load balancing algorithm which can be used for the S-CSCF assignment performed by I-CSCF during the initial registration procedure of subscribers over the IMS architecture. The designed mechanism is implemented and evaluated in the mathematical model of IMS subsystem based on single servers with FIFO queues with the unlimited capacity in the numerical computing environment - Matlab. Two test-cases with different performance conditions of available S-CSCFs are described. The influence of measured latency affected by performance of other nodes (e.g. P-CSCF, I-CSCF, HSS, etc.) is minimized. Each of simulated test-cases is measured with various service times of SCSCFs and inter-arrival times. The obtained results of designed algorithm are compared with well-known selection algorithm – the round-robin algorithm. It is shown that new selection mechanism improved the service latency of whole IMS network. The possible weakness of the designed weight-based algorithm is sensitivity to traffic model over the modelled IMS architecture.
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Models of Queueing Systems
Horký, Miroslav ; Dvořák, Jiří (referee) ; Šeda, Miloš (advisor)
The master’s thesis solves models of queueing systems, which use the property of Markov chains. The queueing system is a system, where the objects enter into this system in random moments and require the service. This thesis solves specifically such models of queueing systems, in which the intervals between the objects incomings and service time have exponential distribution. In the theoretical part of the master’s thesis I deal with the topics stochastic process, queueing theory, classification of models and description of the models having Markovian property. In the practical part I describe realization and function of the program, which solves simulation of chosen model M/M/m. At the end I compare results which were calculated in analytic way and by simulation of the model M/M/m.
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Queueing theory utilization in packet network design and optimization process
Rýzner, Zdeněk ; Zeman, Václav (referee) ; Novotný, Vít (advisor)
This master's thesis deals with queueing theory and its application in designing node models in packet-switched network. There are described general principles of designing queueing theory models and its mathematical background. Further simulator of packet delay in network was created. This application implements two described models - M/M/1 and M/G/1. Application can be used for simulating network nodes and obtaining basic network characteristics like packet delay or packet loss. Next, lab exercise was created, in that exercise students familiarize themselves with basic concepts of queueing theory and examine both analytical and simulation approach to solving queueing systems.
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Queuing Systems of Active Networks for Controlled Packet Sending
Vala, Ondřej ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
This bachelor thesis is describing queueing systems to provide quality of services in telecommunication networks. The work consists of a theoretical and practical part. The theoretical part describes the types of algorithms, which are used in active components and protective mechanisms against queues congestion. In the practical part, there is the analysis of the real Matlab-Simulink model. The last chapter of the practical part is devoted to the comparison of all the systems in terms of packet loss and packet delays in queues at constant input intensity of data streams.
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Queuing theory and virtual factory by using mathematical models
Myška, Martin ; Klimeš, Lubomír (referee) ; Mauder, Tomáš (advisor)
This thesis deals with the modelling of a production line. The topology of the line is based on the real production line of BOSCH DIESEL s.r.o. – Jihlava company. Simulations have been made using Matlab-Simulink-SimEvents software. The created model represents a pilot simulation of the manufacturing process. The model allows to set a deterministic or stochastic approach and use of an auxiliary worker for planning machine maintenances and finding the bottlenecks in the production. As a pilot version the model is simplified, e.g. the short breaks of operators are neglected. The simulation results and comparisons are described in detail later in this document. In order to bring the simulation closer to the real manufacturing process, future improvement options are mentioned.
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|
|
Optimization of Signalling Traffic in IMS Subsystem of NGN Networks
Nagy, Ľuboš ; Orgoň, Miloš (referee) ; Bezpalec, Pavel (referee) ; Novotný, Vít (advisor)
One of causes of increased latency service over the whole IMS network can be unbalanced SIP (Session Initiation Protocol) signalling traffic through CSCF (Call Session Control Function). This thesis is devoted to the proposal of weight-based load balancing algorithm which can be used for the S-CSCF assignment performed by I-CSCF during the initial registration procedure of subscribers over the IMS architecture. The designed mechanism is implemented and evaluated in the mathematical model of IMS subsystem based on single servers with FIFO queues with the unlimited capacity in the numerical computing environment - Matlab. Two test-cases with different performance conditions of available S-CSCFs are described. The influence of measured latency affected by performance of other nodes (e.g. P-CSCF, I-CSCF, HSS, etc.) is minimized. Each of simulated test-cases is measured with various service times of SCSCFs and inter-arrival times. The obtained results of designed algorithm are compared with well-known selection algorithm – the round-robin algorithm. It is shown that new selection mechanism improved the service latency of whole IMS network. The possible weakness of the designed weight-based algorithm is sensitivity to traffic model over the modelled IMS architecture.
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Application of Queueing Theory
VÁŇOVÁ, Eliška
The goal of this thesis was to understand Queueing Theory and use it for analysis of queueing system of hypermarket company PZV. Theoretical part is consists of basic iformations which is necessary to know for application of queueing theory. First chapter is about random variables, random event, random proces, stochastic and Poisson processes and Markov chains. Then was possible to describe queueing theory basic characteristics, parameters, analy-sis, classification and basic models. In the practical part was from the beginning analyze development of custo-mers going through cashier zone. On the base of analysis were customers divided into 4 groups. For these groups were counted characteristics and parameters, next was analyzed the system, but because data were too inaccurate, it was necessary to use different values for the groups and to count analysis for these values. The last step was to find number of cashiers to make system optimal. The result, it was 4 ca-shiers, was unfortunately not accurate. For better results it would be necessary to have more detail data.
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Queuing Systems of Active Networks for Controlled Packet Sending
Vala, Ondřej ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
This bachelor thesis is describing queueing systems to provide quality of services in telecommunication networks. The work consists of a theoretical and practical part. The theoretical part describes the types of algorithms, which are used in active components and protective mechanisms against queues congestion. In the practical part, there is the analysis of the real Matlab-Simulink model. The last chapter of the practical part is devoted to the comparison of all the systems in terms of packet loss and packet delays in queues at constant input intensity of data streams.
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Models of Queueing Systems
Horký, Miroslav ; Dvořák, Jiří (referee) ; Šeda, Miloš (advisor)
The master’s thesis solves models of queueing systems, which use the property of Markov chains. The queueing system is a system, where the objects enter into this system in random moments and require the service. This thesis solves specifically such models of queueing systems, in which the intervals between the objects incomings and service time have exponential distribution. In the theoretical part of the master’s thesis I deal with the topics stochastic process, queueing theory, classification of models and description of the models having Markovian property. In the practical part I describe realization and function of the program, which solves simulation of chosen model M/M/m. At the end I compare results which were calculated in analytic way and by simulation of the model M/M/m.
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