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Zubayer, Anton, and Tai Luong. "Simulation of chaos engineering for Internet-scale software with ns-3." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230214.
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AbstractChaos engineering is the practice of volitionally fault injecting in to a built system with the main purpose of finding the eventual bugs existed in the system before the actual system error occurs. One of the pioneers in this practice is the Simian army, a part of Netflix, where they used random fault injection and linage driven fault injection in its own enormous system with the purposes of suggesting either a relevant approach to chaos engineering or to propose methods of how to uncover the hidden weaknesses. With this paper we seek to attain a simplified illustration about these submitted studies of chaos engineering applied on a simulated Netflix environment in ns-3 with the intention to provide some enlightenment for the principles of chaos engineering and in addition to this we will also at the end of this paper present a suggestion about how to infer an unknown system as a possible application, derived from the knowledges acquired from our chaos journey.”Chaos engineering” är utövandet att själv injicera fel in i ett system för att i första hand hitta potentiella buggar som skulle kunna uppstå innan buggarna framträder i det faktiska systemet som grundades som principer av Simian Army.Slumpmässiga fel injektioner och LDFI (Lineage Driver Fault Injection) hade Netflix redan tidigare utfört i sitt stora system av anledningen att antingen föreslåett tillvägaga˚ngssätt för Chaos Engineering eller att föreslåmetoder att kunna upptäcka dolda svagheter. Med denna rapport är syftet att försöka, med en enkel förklaring av det vi redan vet om Chaos Engineering, att använda inom en simulerad Netflix miljö i ns-3 och intentionen att upplysa om principerna för Chaos Engineering. I slutet av rapporten kommer vi även att framföra ett förslag om hur man kan antyda ett okänt system som en potentiell tillämpning av användandet och lärdomarna av vår ”kaos resa”.
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Mašek, Petr. "Implementace a vyhodnocení komunikační technologie LoRaWAN v simulačním prostředí NS-3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442353.
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The diploma thesis focuses on the description of LPWAN (Low Power Wide Area Network) technologies for use in IoT (Internet of Things) communication scenarios. The theoretical part compares communication technologies operating in the license-exempt frequency band, i.e. Sigfox and LoRaWAN (Long Range Wide Area Network). Furthermore, technologies using the licensed frequency spectrum are discussed, specifically, attention is focused on NB-IoT (Narrow Band IoT). Emphasis is placed on LoRaWAN technology and the properties of the unlicensed frequency band below the 1 GHz, which is utilized by this technology. The practical part of the thesis consists of the evaluation of simulation scenarios using an integrated module in the simulation environment NS-3 (Network Simulator 3). Attention is focused mainly on the analysis of data transmission success using selected communication parameters of LoRaWAN technology. The obtained simulation outputs with a focus on mMTC (massive Machine-Type Communication) communication scenarios confirm the relationship between the number of end devices and gateways, communication distance and transmission reliability, or the limit value for the duty cycle.
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Zeman, Kryštof. "Implementace komunikačního protokolu Wireless M-BUS v simulačním prostředí NS-3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-220408.
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The theoretical part of the thesis focuses on history and development of M2M com- munication, Wireless M-Bus protocol and NS-3 Network Simulator. It briefly describes characteristics of M2M communication, Wireless M-Bus and NS3 simulator. Physical and link layer of Wireless M-bus protocol are described in great detail to provide basics needed for understanding and orientation in the topic. Practical part of the thesis is focused on structure of used Simple Wireless module and basic simulation scenerio is built. The scenerio demostrates basic functions of the module.
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Miklica, Jan. "Návrh modelu pohybu pro nano-zařízení v simulačním prostředí NS-3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220624.
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This thesis focuses on the description of nanocommunication networks, models for wireless communication networks and the description of motion in nanocommunication networks. The practical part describes the settings of the simulation scenarios for the definition of Brownian motion. Description is made for the simulation software NS-3 and N3Sim. In this thesis, the measured results of the simulations are summarized in tables and graphs. From the measured results the regression analysis is prepared. General summary of the results is provided at the end of thise thesis.
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Herbertsson, Fredrik. "Implementation of a Delay-Tolerant RoutingProtocol in the Network Simulator NS-3." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-63754.
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Small mobile devices with networking capabilities are becoming more and more readily available and used. These devices can be used to form mobile ad hoc networks to communicate, where no infrastructure for network communication exist or where it has been destroyed or is overloaded e.g. in a natural disaster such as a hurricane. Such networks are almost never fully connected, and are part of the category of delay/disruption-tolerant networks (DTN) and suffer from limited resources e.g. bandwidth, storage and limited energy supply. The Opportunistic DTN Routing With Window-aware Adaptive Replication (ORWAR) is a delaytolerant protocol intended to be used in disaster relief efforts or emergency operations were a DTN could be a fast way to establish communication. In these kinds of scenarios high success rate together with efficient usage of the networks resources are critical to the success of such operations. ORWAR has been implemented and simulated on a high-level simulator, with promising results. To make a better assessment about what ORWARs performance would be in a real world network, more realistic and detailed simulations are needed. This Master's Thesis describes the design, implementation and evaluation of ORWAR in the network simulator ns-3, which simulates networks down to physical layer. The contributions of this thesis is a extension to ns-3 giving it an framework with support for the bundle protocol and delay-tolerant routing protocols and an evaluation of the ORWAR performance using more detailed simulations. The simulations represent a city scenario in down-town Helsinki city, Finland, were pedestrians, cars and trams form a network to communicate. The simulations with a higher level of detail has added to insight about the protocol. The obtained results showed that the high-level simulation may be overly optimistic and hides implementation details. On the other hand, some assumptions were found to be too pessimistic. For example we have shown that ORWAR actually performs better than the high level simulations, with regard to partial transmissions and that the high-level simulations have rather optimistic assumptions regarding the latency.
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Garro, Alexandra. "Connected Vehicle Co-Simulation for Autonomous Vehicles in Airsim using Ns-3." DigitalCommons@CalPoly, 2021. https://digitalcommons.calpoly.edu/theses/2332.
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Vehicle-to-everything (V2X) communications enables vehicles to communicate directly with each other, as well as roadside infrastructure. Vehicle-to-vehicle (V2V) communication, a subset of V2X communication, enables the vehicle to not solely rely on on-board sensors and allows the vehicle to share information directly to any nearby vehicles. Information shared between vehicles may include a vehicle's position, velocity, and direction, as well as other data. As these are safety-critical applications, rigorous security assessments are needed, yet it can be very expensive, dangerous, and complex to test security vulnerabilities of autonomous vehicles. Therefore, we aim to leverage realistic open-sourced simulators to carry out testing for multiple features, such as security attacks as well as cooperative autonomous driving algorithms. Since there is no open-sourced simulator capable of visually and physically simulating a vehicle and accurately representing its network, this thesis aims to combine a vehicle simulator and network simulator in real-time. Specifically, we incorporate Network Simulator 3 (Ns-3) and Unreal Engine's plugin, Airsim. To run this type of simulation accurately requires high computation power and time, and these requirements can cause delays between the two simulators. To handle the delays during simulation, we propose a system using a time step synchronization technique to pair Airsim and Ns-3. We further elaborate on our incorporation of delaying network packets that arrive earlier than the ideal packet delay. Additionally, we validate our system by demonstrating proof-of-concept attacks. Specifically, we simulate a replay attack and a jamming attack on our system, as well as show that a sybil attack is possible.
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Pieskä, Marcus. "Emulating Software-Defined Small-Cell Wireless Mesh Networks Using ns-3 and Mininet." Thesis, Karlstads universitet, Institutionen för matematik och datavetenskap (from 2013), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-68795.
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The objective of this thesis was to create a network emulator, suitable for evaluatingsolutions in a small-cell wireless mesh SDN backhaul network environment, by integratingexisting software. The most important efforts in this process have been a transparentintegration of Mininet and ns-3 at both the data and the control plane, with ns-3 servingas the front-end. The goal has been to design the system such that solutions revolvingaround fast failover, resilient routing, and energy efficient small cell management may beevaluated. The constituent components include an augmented ns-3 WiFi module withmillimeter wave communication capabilities; a socket API suitable for remote-controllermanagement, as well as the network emulator Mininet. Mininet in turn integrates OpenvSwitch, virtual hosts in the form of Linux network namespaces, and OpenFlow controllers.The work has also included a brief evaluation of the system, which revealed that the designhas a fundamental flaw.SOCRA
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Епифанов, А. С. "Метод экспресс-оценки качества передачи данных при проведении симуляционного моделирования в NS-3." Thesis, ДРУКАРНЯ МАДРИД, 2017. http://openarchive.nure.ua/handle/document/9219.
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Maslák, Roman. "Implementace a vyhodnocení komunikační technologie LTE Cat-M1 v simulačním prostředí NS-3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442354.
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The Diploma work deals with the implementation of LTE Cat-M technology in the simulation tool Network Simulator 3 (NS-3). The work describe LPWA technologies and their use cases. In first are described the main parts of the Internet of Things (IoT) and Machine-to-Machine (M2M) communication. Subsequently are described and defined the most used technologies in LPWA networks. Technologies which are used in the LPWA networks are Sigfox, LoRaWAN, Narrowband IoT (NB-IoT) and Long Term Evolution for Machines (LTE Cat-M), where LTE Cat-M technology is described in more details. Simulations are simulated in simulation tool NS-3 and use LENA module. In NS 3 tool are simulated Simulations, which give us informations of Network state according to different Network set up. At the end are done changes of Radio Resource Control (RRC) states in NS-3 tool. These changes are required for correct implementation LTE Cat-M technology in NS-3 tool. Then we are able to simulate simulations, which meet to definition of LTE Cat-M technology.
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Vadkerti, Gabriel. "Laboratorní úlohy v prostředí NS3 pro předmět Pokročilé komunikační techniky." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-220403.
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This master thesis deals with creating laboratory exercises for students in simulator NS-3, where the IPv4 and IPv6 protocols, unicast and multicast transmission types, quality of services in wireless networks, furthermore protocols TCP and UDP are analyzed. The first section describes the NS-3 network simulator, the Eclipse development environment and the method how to connect them. In the next section protocols IPv4 and IPv6 are presented, the structure of the headers and the technique of fragmentation are described in detail. Based on this a laboratory exercise is created which deals with comparison of protocols IPv4 and IPv6. In the next section the types of transmissions are described, furthermore the multicast transmission type is explained more in detail. In the next practical section the second laboratory exercise is created, which deals with comparison of unicast and multicast transmission types. The subject of the following section is ensuring quality of services in data networks, the EDCA access method is discussed more in detail. In the next section the EDCA access method is implemented in a simulation as a laboratory exercise, in which the impact of the access category of EDCA to different transmission parameters is investigated. The next section deals with protocols TCP and UDP, furthermore with the structure of their headers. In the last section a laboratory exercise is created, in which the properties of the protocols TCP and UDP are compared.
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Padilla, Ryan Michael. "Performance Evaluation of Optimal Rate Allocation Models for Wireless Networks." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3166.
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Convex programming is used in wireless networks to optimize the sending or receiving rates of links or flows in a network. This kind of optimization problem is formulated into a rate allocation problem, where each node in the network will distributively solve the convex problem and all links or flows will converge to their optimal rate. The objective function and constraints of these problems are represented in a simplified model of contention, interference, and sending or receiving rates. The Partial Interference model is an optimal rate allocation model for use in wireless mesh networks that has been shown to be theoretically superior to other conceptual models. This paper compares the Partial Interference model to three other models of wireless networks using the ns-3 simulator to verify these claims. It discusses where the model works as expected, where the model fails to improve network utility, and the limitations inherent to its use.
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Narbutaitis, Tomas. "Saugaus maršrutizavimo Ad Hoc tinkluose tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110831_112815-19717.
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Mobilūs Ad-Hoc tinklai yra labai naudingi įvairiose situacijose, tačiau jų realizacijose vis dar neišspręsta daug problemų ir viena iš didžiausių problemų yra saugumas. Maršrutizavimui reikalingi specialiai suprojektuoti maršruto protokolai ir jie yra gana gerai išvystyti, išskyrus saugumo sritį. Darbe aš labiausiai telkiau dėmesį į įvairias aktyvias atakas prieš ad hoc tinklą, vykdomas iškreipiant maršruto parinkimo procesą ir kompromituojant tinklo paslaugų prieinamumą, duomenų vientisumą ir konfidencialumą, o labiausiai į saugaus maršruto parinkimo protokolų, kurie gali būti naudojami siekiant išvengti šių pavojų, analizę. Naujos koncepcijos saugaus maršruto parinkimo protokolas siūlomas, kaip konkretaus atvejo - iš tiesų didelio kenkiančių mazgų kiekio tinkle sprendimas ir sukurtas nesaugaus ad hoc tinklo modelis, kuris naudojamas siekiant imituoti, gauti ir palyginti keleto saugaus maršruto parinkimo protokolų rodiklius.Mobile Ad-Hoc networks are very useful in certain situations, but raise many challenges and one of the biggest is security. Specially designed routing protocols are required and they are quite well developed except for security area. In this thesis I concentrate on various active attacks on ad-hoc network during routing process, compromising network availability, data integrity and confidentiality and analyze some security aware protocols, that can be used to avoid these risks. New concept routing protocol is proposed, for coping with a specific scenario of really high level of malicious nodes on the network and insecure network model is created, which is used to simulate, get and compare performance metrics of some security aware routing protocols.
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Mohini, Arshi. "CDSSim - Multi UAV Communication and Control Simulation Framework." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1554373574457271.
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Patibandla, Siva Teja. "Development of Mobile Ad-Hoc Network for Collaborative Unmanned Aerial Vehicles." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/3155.
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The purpose of this research was to develop a mobile ad-hoc network for collaborative Unmanned Aerial Vehicles (UAVs) based on a mesh networking standard called IEEE 802.11s. A low-cost, small form-factor, IEEE 802.11a based wireless modem was selected and integrated with the existing flight control system developed at Virginia Commonwealth University (VCU) UAV Laboratory. A self-configurable user-space application on the wireless modem was developed to provide functionality to collaborative algorithms, and to monitor the performance of the wireless network. The RAMS simulator, developed at VCU, was upgraded to support the simulation of advanced networking capabilities by integrating with a simulator called ns-3. The reconfigurability and performance of the IEEE 802.11s mesh network was validated and evaluated by conducting real-world flights. The results show that the IEEE 802.11s is a promising solution for collaborative UAV applications.
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Hlavatý, Josef. "Návrh laboratorní úlohy zaměřené na protokol AODV." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377001.
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This diploma thesis focuses on the MANET Network (Mobile Ad-Hoc Network). There are theoretically elaborated basic information, the characteristics of the MANET network and great emphasis is placed on routing in these networks. In the next chapter the diploma thesis focuses on the Ad Hoc Demand Distance Vector (AODV) routing protocol. It features the characteristics of this protocol and the principle of communication and routing in MANET networks. Hereinafter, the individual reports of the AODV protocol are described in detail. In the third chapter, the thesis introduces the NS-3 simulation environment (network Simulator - 3) and then deals with the design of the MANET network in NS-3 using the AODV routing protocol. The practical part of the diploma thesis is the MANET network simulation and testing with the AODV routing protocol. Laboratory task is built from these simulations and the results of the testing.
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Pecina, Martin. "Návrh laboratorní úlohy zaměřené na protokol OLSR." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377327.
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An ad hoc mobile network is a collection of mobile nodes that are dynamically and arbitrarily located in such a manner that the interconnections between nodes are capable of changing on a continual basis. In order to simplify communication within the network, a routing protocol is used to discover routes between nodes. The primary goal of such an ad hoc network routing protocol is correct and efficient route establishment between a pair of nodes so that messages may be delivered on time. Route construction should be done with a minimum of overhead and bandwidth consumption. This document describes the Optimized Link State Routing (OLSR) protocol for mobile ad hoc networks. The key concept used in the protocol is that of multipoint relays (MPRs). MPRs provide an efficient mechanism for flooding control traffic by reducing the number of transmissions required.
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Babjarčiková, Lenka. "Návrh nových laboratorních úloh pro výuku principů komunikačních protokolů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442405.
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The aim of this master thesis is to create two laboratory exercises in ns-3 network simulator for chosen communication protocols. The chosen protocols are BGP and ICMPv6. The first part of this thesis contains teoretical knowledge used in order to design laboratory exercise. It contains descriptions of funcionality of both protocols and messages they use. This chapter also includes brief description of three options which were considered for implementation of BGP protocol into ns-3 enviroment. The second chapter consists of actual laboratory exercises which were created as a purpose of this thesis. Exercise for BGP protocol deals with creating neighborhoods between routers at autonomous system level, analyzing the way routers communicate within their neighborhoods and how protocol reacts when the connection between two neighbor routers fails. Exercise created for ICMPv6 protocol is focused on its messages and their usage within multiple protocol funcionalities, such as address configuration, link address resolution and error detection.
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AMORIM, Rodrigo Diego Melo. "HTR Heterogeneous Routing Protocol, um protocolo de roteamento para redes ad hoc heterogêneas." Universidade Federal de Pernambuco, 2011. https://repositorio.ufpe.br/handle/123456789/2458.
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Previous issue date: 2011Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco
A popularidade de dispositivos móveis como meio de comunicação tem crescido nos últimos anos devido à facilidade de uso, custo e as mais variadas tecnologias. O aumento no número dessas opções como WiFi, Bluetooth ou até mesmo rede de telefonia móvel permitem uma maior conectividade desses dispositivos móveis na rede. Determinadas tarefas, como compartilhamento de stream de vídeo, implicam diferentes requisitos, o que pode requerer diferentes tecnologias de rede. Nos cenários de emergência, que incluem operações militares, força-tarefa para desastres e grupos de busca e resgate, onde se pressupõe a ausência de infraestrutura, o uso de redes sem fio e a permanente conectividade podem ser requisitos essenciais para realização de algumas tarefas. Para tanto o uso de um protocolo de roteamento que seja adequado a esse ambiente é de fundamental importância. Este trabalho faz um estudo comparativo de um novo protocolo de roteamento para redes heterogêneas ad hoc, chamado Heterogeneous Routing Protocol ou simplesmente HTR, focado em cenários de emergência, com um dos protocolos de roteamento para redes ad hoc mais usado, o OLSR. A fim de fazer uma análise robusta e escalável, o protocolo HTR foi implementado no simulador NS-3 e comparado ao OLSR através de métricas como taxa de entrega, atraso, pacotes perdidos, entre outros
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Martin, Morgan Mackensie. "Functional analysis of hepatitis C virus non-structural protein (NS) 3 protease and viral cofactor NS4A." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1522.
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The hepatitis C virus (HCV) was identified in 1989 as the major causative agent of transfusion-associated non-A, non-B hepatitis and today represents a worldwide health crisis with prevalence estimates of 2.2%. HCV-specific therapeutics have never been more urgently needed. One of the validated drug targets is the non-structural (NS) protein 3 (NS3) membrane-bound protease. The major aim of this thesis was characterization of NS3 allosteric activation by its viral cofactor, NS4A. We hypothesized that there would be specific residues that dominate the interaction between NS3 and NS4A, and further hypothesized that binding and activation may be separate events mediated by different residues.
This thesis details the development of novel cell-based assays for detection of NS3-4A protease activity and heterocomplex formation. The protease assay substrate was a membrane-targeted intracellular protein, which upon proteolysis released a red fluorescent protein (FP) reporter, DsRed-Express, into the cytoplasm; this change was detected by microscopy or quantified by Western blotting. The complex formation assay detected fluorescence resonance energy transfer (FRET) between yellow and cyan FP-tagged NS3 and NS4A, respectively.
Our data shows binding can be functionally separated from activation. We identified two NS4A residues (I25 and I29) important for NS3 binding and two NS4A residues (V23 and I25) important for NS3 activation. Therefore the binding-pockets of these residues are prime targets for small-molecule therapeutic development.
In addition, I have compared the NS3-4A substrate sequence cleavage efficiencies in vivo. I have been able to show that the activation-dependent NS4B/NS5A junction is processed efficiently and the NS4A/NS4B junction is not. I have also shown NS3-4A substrate specificity is not modulated by replicase components; however the specific activity of this enzyme is increased.
The strength of this thesis work stems from the novel and creative development of cell-based assays that can easily be modified to study other membrane-associated proteases. In vitro assays fall short in that they do not take into account the unique micro-environment in which these proteases are found.
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Martins, Arlison Wady Sousa. "Um Ambiente Virtual baseado em Nuvem para Simulação de Redes de Computadores com o NS-3." Universidade Federal do Maranhão, 2016. http://tedebc.ufma.br:8080/jspui/handle/tede/1533.
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The breakthrough in the development of new technologies and network protocols contributed to the growth of computer networks, and consequently increased the need to use simulations to design and analyze these networks. Such simulations need to be evaluated and compared in different scenarios where there are not always available computing resources to execute them. The use of computing resources of cloud shows an interesting approach because of their intrinsic characteristics, elasticity and provisioning capabilities on demand. In this context, this work proposes an architectural model, service and network simulations repository in the Amazon cloud that uses web services technology.
O avanço no desenvolvimento de novas tecnologias e protocolos de redes contribuiu para o crescimento das redes de computadores, e consequentemente aumentou a necessidade de se utilizar simulações para projetar e analisar estas redes. Tais simulações precisam ser avaliadas e comparadas em diferentes cenários, em que nem sempre existem recursos computacionais disponíveis para executá-las. Em virtude disso, a utilização dos recursos computacionais da nuvem se mostra uma abordagem interessante devido às suas características intrínsecas, como a elasticidade e o provisionamento de recursos sob demanda. Nesse contexto, este trabalho propõe um modelo arquitetural, serviço e repositório de simulações de redes na nuvem da Amazon que utiliza a tecnologia de serviços web.
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Xiong, Xinkai. "An Analysis of the Queueing Delays and Throughput of the TCP BBR Congestion Control in NS-3." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-288858.
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BBR is a congestion control recently proposed by Google, unlike the traditional congestion control which uses packet loss as the signal of congestion, BBR uses the estimation of bottleneck bandwidth to control the sending rate. However, recent work shows that BBR suffers from a variety of problems such as large queuing delays with multiple flows in the network. Most of the existing work in this area has so far focused on the performance analysis of BBR. Despite these efforts, there exists still a lack of understanding on how to improve the performance of BBR in different scenarios. In this paper, we first present the behaviour of the original BBR in the Network Simulator 3 (ns-3), then, we provide an improvement that carefully adjusts the pacing rate based on the RTT of the flow, finally, to validate our method, we run simulations varying different bottlenecks, latency, and numbers of flows in both small and large buffer size scenarios on ns-3 network simulator. The results show that our improvement can significantly reduce the queuing delay on the bottleneck at a very small cost of throughput in large buffer scenarios, and also achieve less than 0.1% retransmission rate in small buffer scenarios.BBR är en typ av stockningskontroll som nyligen föreslagits av Google. Till skillnad från traditionell stockningskontroll som använder paketförlust som stockningssignal använder BBR en uppskattning av bandbredden i flaskhalsen mellan sändare och mottagare för att styra sändningshastigheten. Senare arbete visar dock att BBR lider av olika problem, såsom långa förseningar i paketköer med flera flöden i nätverket. Det mesta av det befintliga arbetet inom detta område har hittills fokuserat på att analysera BBR-prestanda. Trots dessa ansträngningar saknas det fortfarande förståelse för hur man kan förbättra BBR:s prestanda i olika scenarier. I den här rapporten presenterar vi först beteendet hos den ursprungliga BBR i nätverkssimulatorn ns-3. Därefter föreslår vi en förbättring som noggrant justerar sändningstakten enligt RTT (Round Trip Time) för flödet. Slutligen, för att validera vår metod, utför vi simuleringar som varierar olika flaskhalsar, fördröjningar och antal paketströmmar i små och stora buffertstorlekar i ns-3. Resultaten visar att vår förbättring avsevärt kan minska köfördröjningar i flaskhalsar för stora buffertstorlekar till en mycket låg kostnad i genomströmning, samt uppnå mindre än 0.1% omsändningshastighet i scenarier med små buffertstorlekar.
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Varmus, Pavol. "Analýza vehicular ad hoc sítě." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-400927.
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This diploma thesis aims to study VANET (vehicular ad hoc network), to describe the theory of this networks and describe attributes of these networks and to set the starting point for practical part. Thesis includes VANETs possibilities, its signal transportation and description of routing protocols. Another goal was to familiarize program NS-3 and set up simulation models in its interface. The main output of the practical part is program which simulates vehicle movement in Brno city and set the communication module which is adapted to fulfill the most realistic transmission capabilities. Practical part is divided to two parts. The goal of the first one was to simulate basic communication in theorized unrealistic scenario and the second part was the more realistic scenario. Overall, throughout the practical part was tested a variety of attributes, such as mobility models, standards, routing protocols and other parameters that provided diversity in final results. All the results, which consisted of summary of basic transmission capabilities and reclassification of the applicability of those technologies in real world, are discussed in the summary of the simulations output.
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Arnaud, Laurence. "Etude des relations entre l'atteinte des cibles cellulaires et la répartition par voie phloémienne d'un herbicide systémique : le glyphosate." Grenoble 1, 1993. http://www.theses.fr/1993GRE10202.
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Le glyphosate est un herbicide systemique phloemien qui inhibe tres efficacement la 5-enolpyruvylshikimate-3-phosphate synthase (epsps)(ec-2. 5. 1. 19). Le glyphosate peut penetrer passivement dans les espaces aqueux internes de la mitochondrie, du chloroplaste et du thylakoide. Dans la cellule isolee de cambium d'erable en culture, existe une activite epsps bien mesurable. Le glyphosate tue ce type de cellule pour une concentration interne apparente de 200 um. Cependant, la rmn du 31p in vivo permet de voir que l'herbicide est pratiquement absent de la vacuole et que le glyphosate atteind dans le cytosol une concentration de 2 mm, en equilibre diffusionnel avec le milieu. Dans le ble et le tabac, l'epsps est presente dans pratiquement tous les organes et intervient dans la biosynthese des acides amines aromatiques et dans la lignification. La systemie phloemienne du glyphosate qui le deplace vers les zones puits joue un role variable selon les especes et les stades de developpement dans l'expression de la phytotoxicite de cet herbicide. Grace a des varietes de tabac exprimant une epsps bacterienne resistante au glyphosate, le role complexe de l'atteinte de l'epsps racinaire, en fonction des conditions de culture, a pu etre mieux cerne. Dans les divers materiels etudies, sous l'action du glyphosate, l'accumulation de shikimate et de shikimate-3-phosphate atteint des niveaux tres differents. Son role dans le declenchement du processus letal ne semble ainsi pas pouvoir etre constant
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Turan, Jonáš. "Modelování PLC komunikace s využitím Network Simulator-3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-317213.
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This thesis deals with analysis and modelling of power line communications. The main aim is to examine the effects influencing transsmision of communication signals on powerline networks and theoretical capacity of the PLC channel using PLC framework created in NS-3. The introduction summarizes the theoretical knowledge in the area of data transmission over power line distribution network. Different types of noise and possibilities of calculation of theoretical transmission capacity are described as well. Several simple simulations are realized in practical part of this paper. These simulations explore the influence of the distance between the transmitter and receiver, length, impedance and number of branches between these nodes, affect of the type of modulation and noise on the transfer function as well as the capacity of the channel. There are also some simulations for large topology based on real position of electrometer. The main focus is to find positions of repeaters to ensure that some nodes of the topology can communicate.
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Sajjad, Muhammad Mohtasim. "A software defined networking based adaptive multimode decentralized mobility architecture for 5G." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/116510/1/Muhammad%20Mohtasim_Sajjad_Thesis.pdf.
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This thesis presents a novel Software-Defined Networking based flexible handover management mechanism for 5G mobile networks. The performance of Distributed Mobility Management process is enhanced through a novel 'Handover Mode Selection' approach, in which the Software-Defined Network Controller evaluates the protocol's mode of operation for the next handover event according to the Mobile Node's current mobility profile. The analytical evaluation and the simulations through ns-3 network simulator of the proposed solution show significant handover performance improvement under high mobility and high session activity scenarios.
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Miško, Lukáš. "Optimalizace směrování v protokolu Ad hoc On-Demand Distance Vector." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413102.
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This thesis contains a theoretical basis for MANET networks. The main focus of the thesis is principles of these networks, their routing protocols and especially on Ad hoc On-Demand Distance Vector (AODV), implementation of this protocol and implementation of new mechanis for peer selection. Thesis contains ETX metric basic and implementation of this metric to AODV protocol. There is a demonstration of simulation of AODV protocol and simulation of AODV-ETX protocol. Simulations are run in Network Simulator 3. AODV and AODV-ETX comparasion are included in thesis.
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Kasianenko, Dmytro. "Model adaptivního streamování videa přes HTTP." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-241039.
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Key tasks of this work are to create the simulation of a wireless network in ns-3 and to stream a video over this network by using MPEG-DASH technology. It describes the tools and methods how to encode a video according to MPEG-DASH. It is explained what is needed to run video server, which uses MPEG-DASH technology to stream videos. Then, it is described how a simulation of wired and wireless WiFi and LTE networks is created. The simulation starts a server and shows how it works, how many nodes can be used and chooses suitable segment duration.
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Horák, Martin. "Modelování PLC komunikace s využitím Network Simulator-3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-241144.
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The diploma thesis deals with the issue of data transmission over power lines, focusing on simulation transmission functions. The theoretical part summarizes basic information on PLC technology and distribution networks, followed by analysis PLC simulator implemented in NS-third In the practical part of the thesis is described implementation of individual types of underground and overhead lines to the PLC simulator. Also been carried simulation scenarios for a simple topology and were designed own simulation scenarios for extended topology and simulations have been carried out various kinds of interference on communication.
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Campestri, Mattia. "Performance Improvement of D2D Random Access in 5G Communications." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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The development of fifth generation mobile networks has laid the ground for the creation of new applicative scenarios, characterized by increasingly demanding requirements. In particular, to satisfy low latency requirements, an aspect to take into account is represented by the random access procedure, performed by devices for initial connection to the network or to switch to a connected state afterwards. Because of the limited amount of resources available for random access, the presence of a high number of devices requesting access at the same time can generate congestion and require multiple access attempts, increasing latency and compromising the fulfillment of the requirements. The problem was already addressed in the scientific literature, with the proposal of a series of solutions to improve the random access procedure. This thesis work aims at enriching these efforts, by leveraging device-to-device communications and the reservation of random access resources, and by proposing a dynamic strategy to alleviate performance deterioration at runtime and intervene on the system with reconfiguration operations, in order to solve possible congestions. The studied scenarios are analyzed by means of the ns-3 network simulator, extended by the additional mmWave and MilliCar modules, for the simulation of 5G networks and device-to-device communications through the cellular sidelink. The results obtained from the simulations have the objective of demonstrating the advantages introduced by the dynamic reconfiguration strategy, and of gaining useful insights on the usage of the proposed enhancements for the random access procedure.
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Petrůj, Jakub. "Modelování a simulace PLC komunikace pro chytré měření s využitím Network Simulator-3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-400919.
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The diploma thesis deals with analysis and modeling of power line communication using NS-3. The introduction part summarizes basic information about PLC technology, distribution grids, and broadband standards. This is followed by the analysis of the transmission line and modulation method. Furthermore, the simulation tool and possibilities of its extension are described. The influence of different cross-section and type of line on channel capacity is examined in the practical part of this paper. The influence of repeaters on bitrate is examined as well. The medium-voltage line was implemented and further scenarios dealing with bitrate or optimal level of noise. The focus of the last part is to find the repeaters on the path and to determine the capacity and bitrate on the path of the large topology.
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Nerini, Matteo. "Network Slicing for IEEE 802.11 Wireless Networks." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21149/.
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Future networks will pave the way for a myriad of applications with different requirements. In such a context, the today’s one-size-fits-all approach will not be able to efficiently address the different demands that verticals impose in terms of QoS and involved data volumes. To this end, network slicing is a new network paradigm which may provide the needed flexibility. It allows to offer multiple logical networks over a common infrastructure, tailored to the services which run on the network.
In today’s Wi-Fi networks, all the users are connected to the same wireless channel, which allows service differentiation only at the traffic level. Thus, in this study, we propose a standard-compliant network slicing approach for the radio access segment of Wi-Fi, often neglected by the literature on network slicing.
We present two algorithms to realize network slicing at the access level. The first assigns resources according to the requirements of the slices in a static way. On the other hand, the second, more advanced, dynamically configures the slices according to the network conditions and relevant KPIs. These techniques can be applied to the IEEE 802.11 standard and, in general, to all the protocols that use Carrier Sensing Multiple Access (CSMA) as channel access technique.
The proposed algorithms were validated through extensive simulations, conducted with ns-3 network simulator and accompanied by theoretical calculations. Particular attention, often neglected in similar simulation-based works, has been paid to the electromagnetic properties of the spectrum, which play a fundamental role in radio communications.
From the conducted simulations, we found that our slicing approaches largely outperform the today’s Wi-Fi access technique. They allow to reach higher goodput (i.e. a lower error probability) and lower latency, when needed. At the same time, tailored slicing saves energy to low-power devices and increases the spectrum efficiency.
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Englund, Johan. "Determining suitability of the IEEE1609 standard for PRT systems." Thesis, Högskolan i Gävle, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-8115.
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Personal Rapid Transit systems have high demands on its reliability and security. Many of the fundamental functions needed by a PRT system can be provided by a wireless radio communication link. The goal of this thesis is to determine if the emerging radio standard for intelligent transportation systems is suitable for providing some of the needed functions. The emphasis of this work is to understand the features of the standard that are important for a PRT system and to verify them with simulation.
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Mašek, Pavel. "QoS model pro mobilní ad hoc síť." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220196.
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The diploma thesis "QoS model for Mobile ad hoc network" focuses on the quality of services in MANET (Mobile Ad-hoc) networks. It describes MANET networks and covers the theoretical analysis of routing protocols with QoS (Quality of Service) support. Furthermore, there is processed the creation process of model MANET networks with the routing protocol DSDV (Destination-Sequenced Distance Vector) in the simulation environment NS-3 (Network Simulator 3) and its extension of QoS support. The used QoS model is subsequently modified to improve core operating parameters. The implementation of QoS parameters as well as the improvement of delay and jitter (the delay between selected packets) is verified by the functional simulation.
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Ozgur, Utku. "Development of a Remotely Accessible Wireless Testbed for Performance Evaluation of AMI Related Protocols." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3177.
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Although smart meters are deployed in many countries, the data collection process from smart meters in Smart Grid (SG) still has some challenges related to consumer privacy that needs to be addressed. Referred to as Advanced Metering Infrastructure (AMI), the data collected and transmitted through the AMI can leak sensitive information about the consumers if it is sent as a plaintext.
While many solutions have been proposed in the past, the deployment of these solutions in real-life was not possible since the actual AMIs were not accessible to researchers. Therefore, a lot of solutions relied on simulations which may not be able to capture the real performance of these solutions. In this thesis, two 802.11s wireless mesh-based SG AMI network testbeds are developed with Beaglebone Black and Raspberry Pi 3 boards to provide a baseline for the simulations. The Raspberry Pi 3 testbed is also configured to be remotely accessible.
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Kuder, Zenon. "Směrovací protokoly pro ztrátové bezdrátové sítě." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219663.
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Tato práce zkoumá vhodnost a požadavky návrhu simulací pro simulátor NS-3 pro případ bezdrátových sítí používaných v měřící infrastruktuře společnosti Kamstrup. V práci je popsán simulátor NS-3 a je vytvořena základní implementace dvou protokolů. Wireless M-Bus jako příklad jednosměrného protokolu pro zařízení napájené z baterií. Simulace Wireless M-Bus je porovnána s daty naměřenými v reálném systému. NS-3 poskytuje flexibilní prostředí pro vývoj simulací různých síťových protokolů, včetně těch určených pro sítě inteligentních měřidel.
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Kolář, Jan. "Simulátor přenosových funkcí silnoproudého vedení v NS3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-220401.
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This thesis deals with the powerline communication focusing on the simulations of channel transfer functions. The introduction summarizes basic information about PLC followed by the analysis of the available PLC Software simulator (implemented in NS-3) and the analysis of implemented noises and interferences and its extensions. One chapter is devoted to possibilities of link capacity calculation. Within the thesis, various methods of calculation of primary parameters of transmission line were implemented and the simulator was compared with other freely available simulators. Subsequently, simulations were carried out focused on channel transfer functions in different topologies, on the impedance changes of branch, on the lengths of branch, and changes in the direct path between communicating nodes.
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Potfay, Attila. "Směrovací protokoly pro MANET sítě se zaměřením na QoS." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220206.
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The main task of this master’s thesis is to simulate the routing protocol AODV (Adhoc On-Demand Distance Vector Routing) to the Network Simulator ns-3 environment, and to realize a model of MANET (Mobile Ad-hoc Network) network with the support of Quality Of Service (QoS). Further implement the protocol AODV in real devices and the involvement of such nodes in the simulation process using the simulator ns-3. This work provides the theoretical basics: it deals with the primary characteristics of MANET, describes in detail the routing protocols MANET with support of QoS, provides information about the Network Simulator ns-3 simulation environment, describes in detail the existing implementation solutions of the protocol AODV in to real devices and provides information about the methods of involvement real devices to the simulation.
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Vala, Ondřej. "Analýza směrovacích protokolů používaných v MANET sítích." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-318162.
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This diploma thesis is analysis of routing protocols used in MANET networks focusing on protocols OLSR, AODV and HWMP. The work consists of a theoretical and practical part. The theoretical part describes the routing protokols, which are used in MANET networks and their applications to FANET networks. In practical part, there are describes of created mobility model in the NS-3, which are used for comparison routing protocols on the created scenarios of mobility according to the qualitative parameters of the networks.
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Gödel, Christoph [Verfasser]. "Wiedergutmachung im Beitrittsgebiet : Die Restitution nach § 3 Abs. 1 Satz 4 VermG für in der NS-Zeit vorgenommene Entziehungen von Unternehmensanteilen aus verfassungsrechtlicher Sicht / Christoph Gödel." Baden-Baden : Nomos Verlagsgesellschaft mbH & Co. KG, 2018. http://d-nb.info/1175742643/34.
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El, Gholami Khalid. "La gestion de la qualité de service temps-réel dans les réseaux de capteurs sans fil." Thesis, Clermont-Ferrand 2, 2014. http://www.theses.fr/2014CLF22537/document.
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Le monde des réseaux de capteurs sans fil ‘RCSF’ a connu de grands progrès au cours de ces dernières années. Ainsi, les RCSF ont pu intégrer divers champs d’application (environnement, militaire, médecine, domotique ...) dont quelques-uns ayant des exigences en termes de qualité de service ‘QdS’. Cependant, la garantie de la QdS dans un RCSF pose des problèmes de recherche non triviaux, à cause de la nature peu fiable de la communication sans fil et des limitations des ressources des nœuds RCSF (processeur, mémoire, énergie ...). Dans le cadre de cette thèse, nous nous sommes focalisés sur les protocoles MAC afin d’améliorer le support de QdS dans les RCSF. Plus particulièrement, le standard IEEE 802.15.4. Les mécanismes de conservation d’énergie proposés par ce standard sont efficaces et présentent une flexibilité par rapport aux besoins des applications. Néanmoins, le temps de sommeil des nœuds affecte considérablement le délai de communication, donnant naissance à un compromis énergie/délai. Pour résoudre ce problème, nous avons amélioré ce standard pour un meilleur support des applications temps-réel. L’approche proposée permet de réduire le délai de communication de manière significative, même pour de faibles rapports cycliques, grâce au nouveau format de la supertrame. Les performances ont été validées par simulation et sur des plateformes de nœuds RCSF réelles. Nous avons proposé également un modèle de simulation pour le standard IEEE 802.15.4 sous le simulateur NS-3In the last years, Wireless Sensor Networks ‘WSN’ knew a tremendous evolution which attracted many applications. WSN has several characteristics that make it a unique research field, such as, WSN nodes’ constraints and the unreliable (lossy) wireless communication. The IEEE 802.15.4 standard is the first standard designed for this type of networks known as LR-WPANs ‘Low-Rate Wireless Personal Area Network’. The energy conservation mechanism proposed by the current standard is quite efficient and very flexible. This flexibility comes from the ability to configure different duty cycles to meet specific applications’ requirements. However, this mechanism has a considerable impact on the end-to-end delay. Our approach resolves the energy/delay trade-off by avoiding the storage of the real-time data in the coordinator during sleep time, more particularly in Multi-source Multi-sink networks. A new superframe structure is adopted and a deterministic reception scheduling is used. In this thesis, we also proposed a new WPAN model for the Network Simulator 3 ‘NS-3’
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Vaubourg, Julien. "Intégration de modèles de réseaux IP à un multi-modèle DEVS, pour la co-simulation de systèmes cyber-physiques." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0022/document.
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Modéliser et simuler (M&S) un système cyber-physique (SCP) peut nécessiter de représenter des éléments provenant de trois domaines d'expertise à la fois : systèmes physiques, systèmes d'informations et réseaux de communication (IP). Le simulateur universel disposant de toutes les compétences nécessaires n'existant pas, il est possible de regrouper des modèles issus des différentes communautés, à l'aide d'un multi-modèle. Les défis sont alors 1) intégrer toute l'hétérogénéité du multi-modèle (formalismes, représentations, implémentations), 2) intégrer des modèles IP de façon à ce qu'ils soient en capacité de représenter le transport de données applicatives produites par des modèles externes et 3) les intégrer de façon à ce qu'ils puissent se compléter, pour représenter ensemble les réseaux IP parfois hétérogènes d'un SCP. Pour parvenir à répondre à ces défis, nous nous inscrivons dans la continuité des travaux de M&S autour de MECSYCO, une plateforme de co-simulation basée sur la notion de wrapping DEVS. Nous proposons de définir un cadre général pour réussir à wrapper en DEVS des modèles IP, avec 1) une structuration des différents niveaux de problèmes pour l'intégration de modèles IP dans une co-simulation (délimitation des objectifs et contraintes du wrapping), et 2) une proposition de stratégie de wrapping DEVS de modèles IP et leurs simulateurs. Nous évaluerons notre approche à travers la démonstration de l'intégration de deux simulateurs IP populaires, et d'exemples concrets de M&S de SCP (avec notamment une interconnexion de modèles entre NS-3 et OMNeT++/INET, et une application industrielle utilisée par EDF R&D)Modeling and simulation (M&S) of cyber-physical systems (CPS) can require representing components from three expertise fields: physics, information systems, and communication networks (IP). There is no universal simulator with all of the required skills, but we can gather and interconnect models provided by the communities, with a multi-model. The challenges are 1) integrating all heterogeneities in a multi-model (formalisms, representations, implementations), 2) integrating IP models in a way enabling them to represent the transport of application data produced by external models, and 3) integrating IP models in a way enabling them to complete each other, to be able to represent CPS heterogeneous IP networks. In order to meet these challenges, we relied our solution on the works around MECSYCO, a co-simulation platform based on the DEVS wrapping principle. We propose to define a comprehensive framework enabling to achieve DEVS wrapping of IP models, with 1) a structuration of different issue levels when integrating IP models in a co-simulation (goals and constraints of the wrapping) and 2) a proposition of a DEVS wrapping strategy for IP models and their simulators. We propose some evaluations of our approach, through the integration of two popular IP simulators, and concrete examples of CPS M&S (inter alia, with an example of a models interconnection between NS-3 and OMNeT++/INET, and an industrial application used by EDF R&D)
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Messineo, Graziano. "Simulatore di Rete NS3 per la valutazione delle prestazioni del sistema LTE." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
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La tesi si incentra sullo studio del simulatore Network Simulator 3 per la simulazione di reti LTE.
Si inizia con l'introduzione allo standard LTE, definendone le tecnologie utilizzate e le innovazioni apportate alle reti di comunicazione.
Si introduce, quindi, il simulatore ns-3 e ci si sofferma sulle funzionalità utilizzate.
Si prosegue con la presentazione e la valutazione di simulazioni del sistema LTE in scenari con uno o due eNodeB e uno o due utenti mobili per verificare il funzionamento del simulatore e del sistema LTE in termini di throughput, ritardi e di funzionalità di handover.
Infine, si presentano simulazioni della rete LTE nello scenario di Bologna tramite l'utilizzo del route mobility model per la generazione di traffico realistico. I risultati mostrano il throughput medio percepito da ciascun utente in funzione della copertura effettuata e suggeriscono potenziali sviluppi futuri in termini di copertura e sviluppo di rete.
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Caselli, Federico. "Protocolli per gestione di informazioni di traffico in reti veicolari ad hoc." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7595/.
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Sviluppo ed implementazione di protocolli per il monitoraggio di traffico stradale sulla piattaforma di simulazione iTETRIS per la raccolta di informazioni da utilizzare in applicazioni di Intelligent Transport System.
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Olivier-Deyris, Laurence. "Etude structurale de la glycéraldéhyde-3-phosphate déshydrogénase d'Escherichia coli." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10175.
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Les structures cristallographiques de la forme holo de la gapdh d'escherichia coli native et d'un mutant n313t ont ete determinees et comparees a la structure cristallographique de la gapdh de bacillus stearothermophilus (formes apo et holo). Ces gapdh, nad dependantes, catalysent la phosphorylation oxydative du d-glyceraldehyde-3-phosphate (g3p) en acide 1,3-diphosphoglycerate (1,3-dpg): g3p+nad#++hpo#2#-#4 = 1,3-dpg+nadh+h#+ elles appartiennent au groupe des gapdh glycolytiques. Alors que les autres gapdh de structure 3d connues ont ete cristallisees en presence de sulfate, analogue du phosphate substrat de la reaction, les gapdh native et mutee de e. Coli ont pu etre cristallisees en presence de citrate, avec addition de nad pour saturer les sites de fixation du coenzyme. Les donnees cristallographiques sont: pour l'enzyme native: groupe d'espace c222#1, maille a=79,14a, b=189,56a, c=122,18a, facteur r=19,7% (58328 reflexions entre 8a et 1,8a). Pour l'enzyme mutee n313t: groupe d'espace c222#1, maille a=79,8a, b=188,8a, c=122,7a, facteur r=20,6% (46779 reflexions entre 8a et 2,1a). Pour les 2 structures, l'unite asymetrique comprend 2 monomeres. Elles ont ete resolues par la methode du remplacement moleculaire, avec pour modele la gapdh de b. Stearothermophilus. La comparaison des gapdh de e. Coli et de b. Stearothermophilus montre: une grande conservation de la structure, malgre une homologie de sequence de seulement 57,6%. Des differences localisees au niveau de certaines boucles et des interfaces, et dans l'orientation relative des domaines catalytiques et de fixation du cofacteur. La comparaison des gapdh native et mutee n313t de e. Coli montre que la zone asn31-va189 pourrait etre impliquee dans la cooperativite. La modelisation des complexes enzyme-substrat montre que le cofacteur nad/nadh ne peut pas etre present en meme temps que le substrat dans l'acylenzyme, et que le site pi est trop loin du substrat pour etre la position du phosphate inorganique reactif
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Kapoun, Vladislav. "Simulační model veřejného osvětlení pro Network Simlator 3." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-220386.
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This thesis is focused on the smart public lighting management possibilities. It describes smart public lighting management itself and the advantages of the new management possibilities compared to the current ones are illustrated as well. Furthermore, it deals with a comparison of the most used light resources and LED light resources. This thesis also outlines NS-3 simulation environment and states its advantages. Theoretical concept for energy-saving smart public lighting management system and its modifications for the needs of simulation is described in the paper. This theoretical concept is simulated and compared with the current smart public lighting management systems as well as with the systems designated by the third party.
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Scaparrotti, Giacomo. "Cross-simulator integration: ns3 as a network simulation back-end for Alchemist." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20440/.
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Innovative distributed systems are often studied with the aid of simulation, especially in the case of large scale and situated systems. One of the key aspects of distributed systems is the presence of a set of nodes which must communicate with each other in order to perform their collective task. Consequently, the behaviour of the network plays a key role in determining how the distributed system will act as a whole, but support for realistic simulation of network communication may not be available in simulators that focus on higher-level phenomena, such as the execution of a program on the nodes belonging to a distributed system. Network simulation is usually performed with dedicated simulators which, on the other hand, mostly focus on low-level aspects, such as the behaviour of the physical channels and of the network protocols. The present works aims at filling this gap between high-level distributed system simulation and low-level network simulation by creating a cross-simulator integration between Alchemist, a simulator for large scale situated distributed systems, and ns3, a network simulator, which has been exploited in order to give Alchemist the ability to accurately simulate the network interactions between the nodes. Finally, the whole system has been tested to demonstrate how different network setups can affect the execution of a program in a distributed system.
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Coufal, Tomáš. "Návrh laboratorních úloh pro výuku síťových technologií a protokolů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-400890.
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Diploma thesis deals with creation of laboratory exercises in ns-3 environment. Each one of three exercises consists of theoretical introduction and instructions to carry out the simulation. The first exercise´s topic is routing protocol BGP. The second exercise is focused on transport protocols TCP, UDP, SCTP. In the last exercise, the basic network devices and topologies are simulated. The ARP and RIPv2 protocols are simulated as well.
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Trávníček, Michal. "Simulácia dátových sietí s využitím priameho vykonávania kódu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220191.
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Purpose of this master thesis was to explain simulation of real network, point to the imperfection during these simulations and try to find out technologies and solutions that could improve credibility of simulation. For this purpose, network simulator ns-3 has been chosen which supports direct code execution together with Quagga software suite. Master thesis describes internet protocol IPv4, UDP protocol, basics of routing and detailed explanation of OSPF routing protocol. Focus in this thesis is also on general description of simulation, its kinds and detail explanation of discrete simulation that is used by ns-3 simulator. Next chapter explains theory of ns-3 simulator, its development, conceptual overview and objects. Direct code execution and Quagga that both help improve credibility of simulation, are described in last chapter of theoretical part of thesis. In practical part of thesis is explained how to install and configure all three implemantaions of ns-3 simulator on Ubuntu, linux distribution. On the basis of obtained knowledge, the simulation model has been designed, also there has been given detailed explanation of how to create new model of simulation and how to analyze its results for all implementation.
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Maréchal, Eric. "Purification et étude de la MGDG synthase de l'enveloppe des chloroplastes d'épinard." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10095.
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Le travail effectue dans le cadre de cette these est une contribution a la connaissance de l'udp-galactose : 1,2-sn-diacylglycerol galactosyltransferase (ec 2. 4. 1. 46), appelee aussi mgdg synthase, une enzyme qui est responsable de la synthese du monogalactosyldiacylglycerol (le lipide majeur de l'enveloppe des chloroplastes). Dans un premier temps (chapitre 1), cette enzyme a ete purifiee. Une fraction enrichie en enveloppe de chloroplastes de feuilles d'epinard est solubilisee par un detergent (le chaps). Cette fraction solubilisee est ensuite enrichie en activite de mgdg synthase par chromatographie sur colonne d'hydroxyapatite-agarose, biogel-p6dg, bleu-dextran-agarose, et chelating sepharose chargee avec du zinc. La proteine purifiee est visualisee par electrophorese sur gel de polyacrylamide, et possede un poids moleculaire apparent de 19 kda. Ce poids moleculaire est confirme par radiomarquage avec un reactif des lysines : la mgdg synthase est reperee car elle est protegee du radiomarquage par son substrat. Le second chapitre presente l'etude cinetique de l'enzyme. La mgdg synthase suit le modele de dilution de surface. Son mecanisme bireactionnel, relativement a ses deux substrats (udp-gal et diacylglycerol) est sequentiel et non ordonne. La specificite de l'enzyme par rapport a son substrat 1,2-sn-diacylglycerol est la plus forte pour le dilinoleoylglycerol. Le troisieme chapitre est une etude biochimique du site catalytique de l'enzyme. Deux sites de fixation distincts existent pour les deux substrats. Le site de fixation de l'udp-gal est masque par des reactifs des lysines (anhydride citraconique), le site de fixation du 1,2-diacylglycerol contient aussi des lysines, ainsi que des cysteines reduites et un metal (probablement du zinc).
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Afifi, Mohammed Ahmed Melegy Mohammed. "TCP FTAT (Fast Transmit Adaptive Transmission): A New End-To- End Congestion Control Algorithm." Cleveland State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=csu1414689425.
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