Wyniki wyszukiwania - BazTech

1

Evaluating a Proposed Urban Transportation System Using Advance Transport and Land-Use Modelling Framework

Akuh Raymond, Zhong Ming, Raza Asif

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 3

234--244

EN

The effect of traffic congestion, emission, and road accident on cities that depend solely on motor vehicles make them unsustainable. Increased mobility from rapid urbanization has placed great demand on the transport system of such cities. To meet the increasing demand, modelling travel demand based on the transport network has become a necessity for sustainable urban development. In this study, an advanced transport and land-use modelling framework was developed to evaluate a transport system of a proposed new city. Furthermore, transport (road) network connectivity indices were used to measure the level of connectivity of the transport network. The findings show that the proposed transport system may not support the sustainable urban development of the new city due to the low level of network connectivity. The result further revealed that about 52% of the residents will depend on auto modes of transportation making the new city car-dependent rather than transit-dependent. Specifically, all corridor road links showed a high level of traffic congestion problem. The alternative of building more rails or a bus rapid transit (BRT) system connecting the main and a new city is worth considering when proposing an urban transport system. The advanced transport and land-use modelling framework developed in this study to evaluate the performance of the transportation system could serve as a decision-support system (DSS) towards sustainable planning and development of both old and new cities.

2

Model for measurement of flow installation time in SDN switch

Kaczmarek S., Litka J. A.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2017

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nr 8-9

974--977, CD

EN

SDN is the approach in telecommunication networks that separates control plane from data forwarding plane by specifying a single network entity as a controller that defines rules (called flows) of traffic forwarding for the switches connected to it. The time that is required for installation of these rules might be a hindrance for the overall performance of SDN network. In the paper, a model for testing and evaluating the influence of traffic payload on flow installation time is presented as well as an implementation of the early experiments’ results are provided.

PL

SDN to rozwiązanie dla sieci telekomunikacyjnych, które separuje płaszczyznę sterowania ruchem od płaszczyzny przesyłania informacji poprzez zastosowanie pojedynczego sterownika jako elementu sieci, który definiuje zasady (nazywane przepływami) kierowania ruchem dla podłączonych do niego switchy. Czas instalacji tych zasad może mieć wpływ na jakość i wydajność całej sieci. W artykule przedstawiono model do testowania i ocenienia wpływu obciążenia ruchem na czas instalacji przepływu oraz opis implementacji i wyniki wstępnych doświadczeń.

3

Analysis of Performance and Efficiency of Hardware and Software Firewalls

Konikiewicz W., Markowski M.

Journal of Applied Computer Science Methods

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2017

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Vol. 9 No. 1

49--63

EN

Firewalls are key elements of network security infrastructure. They should guarantee the proper level of security and, at the same time, the satisfying performance in order to not increase the packet delay in the network. In the paper, we present the comparative study on performance and security of a few firewall technologies including hardware, software and virtual solutions. Three important criteria are considered: the maximal throughput of firewall, the introduced delay and the ability to resist Denial of Service attacks. We report results of experiments, present analysis and formulate a few practical conclusions.

4

QoS Requirements as Factor of Trust to 5G Network

Tikhvinskiy V., Bochechka G., Gryazev A.

Journal of Telecommunications and Information Technology

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2016

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nr 1

3--8

EN

Trust to modern telecommunications networks plays an important role as a driver of technological and market success of any technology or telecommunication services. Most of the technological approaches to this problem are focused only on network security and do not include such a factor as the quality of service (QoS), which also plays an important role in the formation of trust both from the consumers and the regulator. The future 5G mobile technology will be the engine of development of telecommunications until 2020 and the formation of trust to the 5G networks is one of the main tasks for developers. The authors present the view on the trust to 5G networks in the plane of QoS requirements formation and QoS management. QoS requirements to 5 G networks were determined on the basis of three main business models of services: xMBB, M-MTC and U-MTC and the need to ensure user trust to networks. Infrastructure requirements for QoS control and spectrum management network entities which are based on Network Function Virtualization (NFV) principles have been formed.

5

Research and analysis of the network performance in data transmission aspect

Kamińska-Chuchmała A.

Rynek Energii

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2015

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Nr 1

104--107

EN

In an era of rapidly expanding Internet network, which can plays role as a transmission medium in smart metering communication, due to the modernization and development of new network connections, as well as the possibility of higher throughput, investigations over network performance must be repeated periodically. Moreover, the issues of end users or Internet users are also important, who are ever more demanding about the size of the data collected and the speed of transmission. Therefore, active experiment was performed, which included download speeds between servers that are located on different continents and then, the results in terms of network performance were analysed. Measurement studies were performed in two different seasons of year 2014: in the spring and winter, in order to determine also the possible impact of atmospheric factors on the behaviour of the network and clients. For the preparation and implementation of active measurement experiment global research network - PlanetLab - was used.

PL

W dobie szybko rozwijającej się sieci Internet, która może występować jako medium transmisyjne w komunikacji smart metering, ze względu na modernizację lub tworzenie nowych połączeń sieciowych, jak również możliwości większej przepustowości należy cyklicznie powtarzać badania nad jej wydajnością. Dochodzą tu kwestie odbiorców końcowych, czyli użytkowników sieci Internet, którzy mają coraz większe wymagania co do wielkości pobieranych danych jak i szybkości transmisji. W związku z tym dokonano aktywnego eksperymentu pomiarowego w którym została zmierzona m.in. prędkość pobierania danych pomiędzy serwerami zlokalizowanymi na różnych kontynentach a następnie przeanalizowano wyniki pod kątem wydajności sieci. Badania pomiarowe wykonano w dwóch różnych porach 2014 roku: wiosną i zimą, aby móc również określić ewentualny wpływ czynników atmosferycznych na zachowania sieci oraz klientów. Do opracowania i wykonania aktywnego eksperymentu pomiarowego posłużono się globalną siecią badawczą PlanetLab.

6

Performance Analysis of Virtual Computer Network Based on Cisco Cloud Services Router 1000v in a Private Cloud Environment

Lota S., Markowski M.

Journal of Applied Computer Science Methods

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2015

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Vol. 7 No. 2

117--132

EN

Virtualization of physical network devices is a relatively new technology, that allows to improve the network organization and gives new possibilities for Software Defined Networking (SDN). Network virtualization is also commonly used for testing and debugging environments, before implementing new designs in production networks. Important aspect of network virtualization is selecting virtual platform and technology, that offer maximal performance with minimal physical resource utilization. This article presents a comparative analysis of performance of the virtual network created by the virtual CSR1000v and virtual machines running Windows 8.1 on two different virtual private cloud platforms: VMware vSphere 5.5 and Microsoft Hyper-V Server 2012 R2. In such prepared testbed we study the response time (delay) and throughput of virtual network devices.

7

Seaport network performance measurement in the context of global freight supply chains

Lam Jasmine Siu Lee, Song Dong-Wook

Polish Maritime Research

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2013

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S 1

47--54

EN

A global distribution channel with a reliable freight transport system is essential in the contemporary world economy. Acting as trade facilitators, seaports are important players in the system. The study of the role of ports in supply chain management has recently drawn increasing attention from researchers and industry professionals alike. However, prior works mainly gathered the views from ports and terminals. To the authors’ knowledge, no attempt by previous empirical studies has been made to cover the perspective from shippers and logistics providers, who are obviously taking a serious role in the process of global freight movements as major stakeholders. It becomes thus imperative to assess a port’s supply chain orientation and performance from the perspective of the port users in the supply chain. Studying ports in the network context would be even more beneficial to capture the complexity needed to understand port performance and its interaction with various stakeholders. Drawing reference from multi-disciplinary fields, this paper aims to fill in the gap by developing a so-called unified framework for analysing port’s integration in global freight supply chains including shipping line networks, hinterland and intermodal transport network, and even urban network. The framework embraces a wider group of stakeholders involved, for example, terminal operators, port authorities, shippers, shipping companies, inland transport providers, freight forwarders/logistics service providers, cities and other ports in the networks. A port that is a key node in these networks simultaneously would be able to create and sustain value for port stakeholders. Port authorities and operators can refer to the framework as their network performance indicators so as to obtain a better understanding of the various considerations in a port’s network performance and to assist in positioning the port within the complex dynamics in the context of global freight supply chains. Finally, the framework developed in the paper can serve as a guide to empirical examinations of an emerging theme – a network-oriented performance by seaports along global freight supply chains – leading to various possible channels in future research.

8

Traffic type influence on performance of OSPF QoS routing

Czarkowski M., Kaczmarek S., Wolff M.

Journal of Telecommunications and Information Technology

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2013

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nr 3

19--28

EN

Feasibility studies with QoS routing proved that the network traffic type has influence on routing performance. In this work influence of self-similar traffic for network with DiffServ architecture and OSPF QoS routing has been verified. Analysis has been done for three traffic classes. Multiplexed On-Off model was used for self-similar traffic generation. Comparison of simulation results was presented using both relative and non-relative measures for three traffic classes. Results were commented and analyzed. The basic conclusion is that performance for streaming and best-effort class for self-similar traffic is higher than performance for the same class with exponential traffic (Poisson). The other important conclusion is relation between performance differences and offered traffic amount.

9

Markov Modulated Bernoulli Process in modeling network traffic

Włodarski P.

Pomiary Automatyka Kontrola

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2010

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R. 56, nr 12

1513-1515

EN

A big impact of self-similar nature of network traffic on queueing performance and Quality of Service in computer networks involves new modeling techniques to provide low computational complexity and better approximation of the real traffic. A discrete-time Markov modulated Bernoulli process is one of the traffic models that captures fractal behavior and can be used in performance testing of queueing systems such as routers or switches. In this paper the model is presented and evaluated from the point of view of the desired self-similarity level. New parameter values that give better results for estimation of Hurst exponent has been proposed. Simulation results are compared with the literature data.

PL

Duży wpływ samopodobnego charakteru natężenia ruchu w sieciach komputerowych na efektywność pracy i poziom usług (Quality of Service) w sieci powoduje powstawanie nowych technik modelowania ruchu o niskiej złożoności obliczeniowej, lepiej dopasowanych do rzeczywistego ruchu. Proces Bernoulliego modulowany łańcuchem Markova będący dyskretnym procesem stochastycznym, ma właściwości które powodują, że przy odpowiednim doborze parametrów może on stanowić dobry model natężenia ruchu w sieci uwzględniający zjawisko samopodobieństwa, a co za tym idzie, może być z powodzeniem stosowany do testowania systemów kolejkowych zarówno teoretycznych jak i rzeczywistych takich jak routery czy switche. W artykule zaprezentowano i sprawdzono model pod kątem możliwości osiągnięcia założonego poziomu samopodobieństwa. Zaproponowano nowe wartości parametrów modelu dające lepsze rezultaty estymacji wykładnika Hursta. Wyniki symulacji porównano z danymi literaturowymi.

10

Thermal rating sposobem na poprawę wydajności polskich sieci energetycznych

Biedrzycka D.

Nowa Energia

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2010

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nr 2

33--35

PL

Przed polską energetyką stoją dzisiaj nowe wyzwania, prawdopodobnie największe od czasów początków elektryfikacji kraju. Dynamicznie zmienia się struktura przesyłu, dołączani są nowi odbiorcy oraz nowi rozproszeni producenci energii. W obliczu tych zmian polskie sieci przesyłowe z roku na rok stają się coraz mniej efektywne. Jeśli przypomnimy również awarie wynikające z braku regularnych napraw i konserwacji na przestrzeni lat, rozwiązanie wydaje się jedno - musimy budować nowe linie przesyłowe. Ale czy jest to jedyna droga?

11

Metodyka oceny mechanizmów integracji sieci IPv4 i Ipv6

Furtak J., Świerczyński Z., Malinowski T.

Biuletyn Instytutu Automatyki i Robotyki

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2010

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R. 16, nr 29

59-72

PL

W artykule przedstawiono metodykę oceny mechanizmów integracji sieci Ipv4 i IPv6 dla przypadków: "wyspy IPv6" podłączone przez środowisko IPv4 i "wyspy Ipv4" podłączone przez środowisko IPv6. Ocena poszczególnych mechanizmów jest oceną względną w stosunku do rozwiązania bazowego (odpowiednio środowisko tylko-IPv6 i tylko-IPv4) i obejmuje: ocenę wydajności mechanizmu integracji uwzględniającą przepustowość, utracone pakiety, opźnienie i fluktuacje opźnienia oraz parametry niemierzalne takie jak: łatwość konfiguracji i diagnozowania mechanizmu, możliwość automatyzacji konfigurowania, adaptacji do zmian i ograniczenia stosowania mechanizmu.

EN

This paper considers an evaluation methodology for IPv4 and IPv6 networks integrated solutions in the following cases: IPv6 domains connected via an IPv4 environment and IPv4 domains connected via an IPv6 environment. The evaluation of a particular solution is relative to its base solution (i.e.: IPv6-only environment or IPv4-only environment) and includes: an evaluation of the integration solution performance and throughput, lost packets, latencies and fluctuations, as well as some immeasurable parameters (e.g.: configuration difficulties, diagnostics, auto-configuration possibilities, adaptation to changes, and limitations of the use).

12

Applications of commercial data analysis software for testing a telecommunications network

Paczocha J.

Journal of Telecommunications and Information Technology

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2002

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nr 3

69-72

EN

This paper shows practical aspect in application commercial software to analysis data concerning information from telecommunication network. The following items are discussed: example of network estimation methodology, the main advantages of network testing system delivering information concerning quality of service (QoS) and network performance (NP) from the user's perspective, general testing system description and data analysis model and example forms of presentation.