Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "network calculus" wg kryterium: Temat


Wyświetlanie 1-10 z 10
Tytuł:
Some Principles of Network Calculus Revisited
Autorzy:
Borys, A.
Aleksiewicz, M.
Rybarczyk, D.
Wasielewska, K.
Powiązania:
https://bibliotekanauki.pl/articles/226229.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
greedy shapers
network calculus
service curve
Opis:
Network calculus is a mathematical theory dealing with queueing problems in packet-switched computer networks. It provides algorithms to determine resource requirements of traffic flows using arrival and service curves and describes delays and backlogs in network systems. Network calculus framework is based on a min-plus algebra which allows to transform complex network optimization problems into analytically tractable ones. Recently, a fundamental book on principles, tools, techniques, and applications of network calculus, entitled: Network Calculus. A Theory of Deterministic Queuing Systems for the Internet, has been published by J. Y. Le Boudec and P. Thiran. Here, we refer to it in our refinements of proof of one important theorem and its extension. The objective of this paper is twofold. First, we complete one of basic results regarding a network element that is called in network calculus a greedy shaper. Second, we present also the results of some illustrative calculations and measurements of network service curve. They aim in better understanding of its properties.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 3; 279-284
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bandwidth Estimation Using Network Calculus in Practice
Autorzy:
Wasielewska, Katarzyna
Borys, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/226756.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bandwidth estimation
network calculus
quality of service
internet traffic
Opis:
An available bandwidth at a link is an unused capacity. Its measuring and/or estimation is not simple in practice. On the other hand, we know that its continuous knowledge is crucial for the operation of almost all networks. Therefore, there is a continuous effort in improving the existing and developing new methods of available bandwidth measurement and/or estimation. This paper deals with these problems. Network calculus terminology allows to express an available bandwidth in terms of a service curve. The service curve is a function representing a service available for a traffic flow which can be measured/estimated in a node as well as at an end-to-end connection of a network. An Internet traffic is highly unpredictable what hinders to a large extent an execution of the tasks mentioned above. This paper draws attention to pitfalls and difficulties with application of the existing network calculus methods of an available bandwidth estimation in a real Internet Service Provider (ISP) network. The results achieved in measurements have been also confirmed in simulations performed as well as by mathematical considerations presented here. They give a new perspective on the outcomes obtained by other authors and on their interpretations.
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 1; 133-138
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Bounds on Cumulative Teletraffic Using Min-Plus Convolution
Autorzy:
Borys, A.
Powiązania:
https://bibliotekanauki.pl/articles/226426.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
network calculus
bounds on cumulative teletraffic curve
min-plus convolution
Opis:
Ideas and results published in two papers by R. L. Cruz in IEEE Transactions on Information Theory in 1991 gave rise to what is called now network calculus. A key role in it plays a certain inequality characterizing the behaviour of cumulative traffic curves. It defines the so-called burstiness constraint by which many kinds of traffics can be described, as for example those occurring in computer networks. Interpretation of this constraint, which can be expressed in two equivalent forms: with and without the use of min-plus convolution, can be found in papers of R. L. Cruz. Nothing however was said about how to obtain it practically, for example, for each of representatives of a family of measured cumulative traffic curves being upperbounded. This problem is tackled in this paper, and as a result, a relation between the Cruz's constraining function and an upper-bounding function of measured traffic curves is found. The relation obtained is quite general and valid also for the case of non-fulfilment of the so-called sub-additivity property by traffic curves. For the purpose of its derivation, a notion of sub-additivity property with some tolerance Δ was introduced, and the corresponding theorem exploiting it formulated and proved. Further, to complement discussion of the above relation, a minimal burstiness constraint was added to the original Cruz's inequality and related with a lower bound of a family of measured cumulative traffic curves. The derivations presented in this paper are illustrated by examples.
Źródło:
International Journal of Electronics and Telecommunications; 2012, 58, 4; 315-322
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detailed Consideration of Graphical Calculation of Min-Plus Convolution in Deterministic Network Calculus
Autorzy:
Borys, A.
Powiązania:
https://bibliotekanauki.pl/articles/226084.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
convolution
network calculus
min-plus algebra
graphical construction of min-plus convolution
Opis:
The convolution operation used in deterministic network calculus differs from its counterpart known from the classic systems theory. A reason for this lies in the fact that the former is defined in terms of the so-called min-plus algebra. Therefore, it is oft difficult to realize how it really works. In these cases, its graphical interpretation can be very helpful. This paper is devoted to a topic of construction of the min-plus convolution curve. This is done here in a systematic way to avoid arriving at non-transparent figures that are presented in publications. Contrary to this, our procedure is very transparent and removes shortcomings of constructions known in the literature. Some examples illustrate its usefulness.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 2; 217-222
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Contribution to the System : Theoretic Approach to Bandwidth Estimation
Autorzy:
Borys, A.
Wasielewska, K.
Rybarczyk, D.
Powiązania:
https://bibliotekanauki.pl/articles/226012.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
network calculus
rate chirps
bandwidth estimation
nonlinear and/or linear parametric traffic systems
Opis:
The network calculus provides a theoretical background for description of traffic in computer networks. Using this tool in explanation of the so-called pathchirp method of measuring the available bandwidth, the validity and range of application of some relationships exploited are verified in this paper. The derivations are carried out in a wider context than that considered in a recent paper by Liebeherr et al. published in IEEE/ACM Transactions on Networking on network bandwidth estimation, providing thereby new insights and outcomes. These results, summarized in a table, show a means of bounding the service curve, depending upon its convexity or non-convexity property assumed and upon the linearity or non-linearity of a network considered. Moreover, it is shown here that the nonlinear network example analyzed by Liebeherr et al. can be viewed equivalently as a linear parametric network. For this network, the behaviour of the cross traffic is considered in a more detail, too.
Źródło:
International Journal of Electronics and Telecommunications; 2013, 59, 2; 141-149
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A delay reliability estimation method for Avionics Full Duplex Switched Ethernet based on stochastic network calculus
Oparta na stochastycznym rachunku sieciowym metoda estymacji niezawodności czasu transmisji dla przełączanej pokładowej sieci ethernetowej typu AFDX umożliwiającej równoczesną transmisję dwukierunkową
Autorzy:
Wu, Z.
Huang, N.
Li, R.
Zhang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/301884.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
reliability estimation
delay upper bound
stochastic network calculus
traffic envelope function
ocena niezawodności
górna granica opóźnienia
stochastyczny rachunek sieciowy
funkcja obwiedni ruchu telekomunikacyjnego
Opis:
The delay reliability estimation is required in order to guarantee the real-time communication for avionics full duplex switched Ethernet (AFDX). Stochastic network calculus (SNC) can be applied to estimate the reliability with a delay upper bound. However, only linear deterministic traffic envelope function is used to bound its traffic, which cannot represent the traffic randomness and is far from practice. In this paper, a stochastic traffic envelope function, which randomizes the input of SNC, is proposed to solve the problem. A new probabilistic algorithm is derived to estimate the delay reliability based on stochastic envelope functions. A test was conducted to demonstrate our method on an AFDX testbed, and the test results verify that the estimation of delay reliability via our algorithm is much closer to the empirical estimation.
Ocena niezawodności czasu transmisji (czasu opóźnienia) jest niezbędną procedurą gwarantującą komunikację w czasie rzeczywistym za pośrednictwem przełączanej pokładowej sieci ethernetowej typu AFDX (Avionics Full Duplex Switched Ethernet), która umożliwia równoczesną transmisję dwukierunkową. Stochastyczny rachunek sieciowy (SNC) można stosować do oceny niezawodności przy zadanej górnej granicy opóźnienia. Do tej pory jednak, do ograniczania ruchu telekomunikacyjnego stosowano tylko liniową deterministyczną funkcję obwiedni (traffic envelope), która nie oddaje losowości ruchu telekomunikacyjnego i odbiega dalece od rzeczywistości. W niniejszej pracy zaproponowano rozwiązanie tego problemu wykorzystujące stochastyczną funkcję obwiedni ruchu telekomunikacyjnego. Wyprowadzono nowy algorytm probabilistyczny, który pozwala ocenić niezawodność czasu transmisji na podstawie funkcji obwiedni. Przeprowadzono badanie, w ramach którego testowano zaproponowaną metodę w środowisku testowym AFDX; wyniki testu pokazują, że ocena niezawodności czasu transmisji z wykorzystaniem zaproponowanego przez nas algorytmu jest znacznie bardziej zbliżona do estymacji empirycznej.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 2; 288-296
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Consideration of a general model of stochastic service curve for communication networks
Autorzy:
Wasielewska, K.
Borys, A.
Powiązania:
https://bibliotekanauki.pl/articles/117055.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
communication networks
stochastic service
communication system
maritime telecommunications area
Quality of Service (QoS)
stochastic network calculus
modelling of model of stochastic service curve
stochastic service curve
Opis:
In this paper, a general framework for modelling stochastic service curves for communication networks is presented. It connects with each other two approaches to the traffic analysis and performance evaluation of communication systems, namely, the one which is called a deterministic network calculus with its stochastic counterpart. Thereby, it enables to treat any communication traffic in a consistent way. Further, as we show here, it enables also achieving new results. Derivation of the above model is presented in details in this paper. Finally, some hints are given how the method presented in this article could be applied in maritime telecommunications area.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 1; 159-164
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of descriptions of continuous-time and teletraffic systems
Porównanie opisów systemów teleinformatycznych oraz ciągłych w czasie
Autorzy:
Borys, A.
Aleksiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/389811.pdf
Data publikacji:
2012
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydawnictwo PB
Tematy:
network calculus
basic properties teletraffic systems
linearity
causality
time-invariance
associativity
commutativity
infimum convolutions
rachunek sieciowy
liniowe i niezależne od czasu systemy teleinformatyczne
własności splotu w algebrze min-plus
Opis:
In a fundamental book [5] on the so-called network calculus and research papers using this technique, as for example those cited in this paper, the notion of causal linear time-invariant teletraffic systems (networks) is used. It has been mentioned in [5] that these systems are analogous to the causal linear time-invariant systems (circuits) described by integral convolution (or convolution sum in the case of discrete ones) in classical systems theory. Note that networks considered in the network calculus are described by other type of convolution that uses the infimum operation. Moreover, the algebra used in the above technique is also different. This is the so-called min-plus (or max-plus) algebra. Therefore, it is not obvious that the teletraffic systems (networks) described by the infimum convolution fulfill the following basic properties: linearity, causality, time-invariance, associativity and commutativity of their convolution operator, known from the classical theory of systems. The objective of this paper is to prove or show in detail that the above properties hold.
W znanej monografii nt. rachunku sieciowego (network calculus), napisanej przez J.-Y. Le Boudeca i P. Thirana, zostało wprowadzone pojęcie liniowych systemów teleinformatycznych niezależnych od czasu. Wskazano w niej na podobieństwa istniejące pomiędzy powyższą klasą systemów a liniowymi systemami analogowymi niezależnymi od czasu, jednakże zrobiono to w sposób dosyć pobieżny. W tym artykule podobieństwa te są przeanalizowane w sposób systematyczny, a także bez uciekania się do bardzo abstrakcyjnej teorii systemów opisywanych za pomocą algebry min-plus – jedynie przy wykorzystaniu elementarnych pojęć matematyki wyższej. Wiele przedstawionych tutaj wyprowadzeń nie było dotychczas nigdzie publikowanych, jak na przykład twierdzenie 1.
Źródło:
Zeszyty Naukowe. Telekomunikacja i Elektronika / Uniwersytet Technologiczno-Przyrodniczy w Bydgoszczy; 2012, 16; 5-15
1899-0088
Pojawia się w:
Zeszyty Naukowe. Telekomunikacja i Elektronika / Uniwersytet Technologiczno-Przyrodniczy w Bydgoszczy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Logical network design of microbearing systems
Autorzy:
Wierzcholski, K.
Powiązania:
https://bibliotekanauki.pl/articles/242043.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
artificial neural network
propositional calculus application
optimum of solutions
Opis:
This paper presents the some applications of logical network analysis in topological form as an Artificial Neural Networks (ANN) intelligence component implemented regard to the optimum calculations of micro-bearing operating parameters such as hydrodynamic pressure, carrying load capacity, and optimum measurements of friction forces, friction coefficient and micro-bearing wear. Efficient functioning of slide micro-bearings systems require to choice the proper journal shapes, bearing materials, roughness of bearing surfaces and many other features to which belongs capability to the processes and control. Artificial intelligence of micro-bearing leads to the creating and indicating of the network logical models to describe most simple and most proper topological graphical schemes presenting the design of anticipated processes. Application of the logical network analysis into the micro-bearing HDD design is the subject-matter of this paper. Mechanism of neuron activity, basic scheme of detection system in modern of Atomic Force Microscope, tip radius estimation, input impulse, tribo-topology logical network scheme mechanism, tribo-topology logical network analysis scheme mechanism, the pressure distributions in cylindrical micro-bearings caused by the rotation in circumferential direction and magnetic field, the view from the film origin and from film end are presented in the paper.
Źródło:
Journal of KONES; 2011, 18, 2; 455-462
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
N-Body Potential Interaction as a Cost Function in the Elastic Model for SANET Cloud Computing
Autorzy:
Chaczko, Z.
Resconi, G.
Chiu, C.
Aslanzadeh, S.
Powiązania:
https://bibliotekanauki.pl/articles/227216.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
elastic network model
cloud computing
Sensor-Actor networks
matrix calculus
N-Body interactions
cost functions
Opis:
Given a connection graph of entities that send and receive a flow of data controlled by effort and given the parameters, the metric tensor is computed that is in the elastic relational flow to effort. The metric tensor can be represented by the Hessian of the interaction potential. Now the interaction potential or cost function can be among two entities: 3 entities or 'N' entities and can be separated into two main parts. The first part is the repulsion potential the entities move further from the others to obtain minimum cost, the second part is the attraction potential for which the entities move near to others to obtain the minimum cost. For Pauli's model [1], the attraction potential is a functional set of parameters given from the environment (all the elements that have an influence in the module can be the attraction of one entity to another). Now the cost function can be created in a space of macro-variables or macro-states that is less of all possible variables. Any macro-variable collect a set of micro-variables or microstates. Now from the hessian of the macro-variables, the Hessian is computed of the micro-variables in the singular points as stable or unstable only by matrix calculus without any analytical computation - possible when the macro-states are distant among entities. Trivially, the same method can be obtained by a general definition of the macro-variable or macro-states and micro-states or variables. As cloud computing for Sensor-Actor Networks (SANETS) is based on the bonding concept for complex interrelated systems; the bond valence or couple corresponds to the minimum of the interaction potential V and in the SANET cloud as the minimum cost.
Źródło:
International Journal of Electronics and Telecommunications; 2012, 58, 1; 63-70
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies