1,720,993 research outputs found
User contribution in peer-to-peer communities
No full textSoftware and Computer TechnologyElectrical Engineering, Mathematics and Computer Scienc
Tribler Download Core Improvement
No full textBitTorrent is a popular peer-to-peer file sharing protocol. From a user’s perspective, it is important that a BitTorrent client downloads the files as fast as possible. The socially enhanced BitTorrent client called Tribler – from the Delft University of Technology and the Vrije Universiteit – was presumed to be lacking in speed. This presumption started this thesis’ research project. The research focused on two questions. How poor is Tribler’s download performance and what determines the performance of a BitTorrent client in general? To understand the problem, we need to be aware that the limited available upload capacity of the peers in the swarm is a speed bottleneck and that one own’s upload capacity is a valuable, but limited currency that can be exchanged for speed from others. However, it is not known which behaviour is best. In order to solve this mystery, we have to compare different behaviours through measurement. Important aspects to measure include: \u95 Peer discovery and try out, measured by connection attempts and optimistic unchokes. \u95 Implementation of the tit-for-tat algorihtm, measured by chokes and unchokes. To measure and analyse these aspects, two approaches were taken. Our first de- sign involved modifying existing BitTorrent clients to log internal events, but its applicability was limited to open source clients. As a result, we came with a design that analysed network traffic and was therefore applicable to all clients. However, a wrongly taken design decision limited its analysis power. The knowledge gained from our analysis is that the initial phase and the end phase of a download are important. For the initial phase, a good discovery of peers required. For the end phase, a different piece selection algorithm is required. There are also some questions left that need to be answered and work to be done. Questions left are: \u95 Do different peer discovery algorithms benefit in different situations? \u95 Does the Mainline BitTorrent client benefit from its new DNA service or is it malware? Future work involves improving our measuring tool and answering these questions.Parallel and Distributed SystemsElectrical Engineering, Mathematics and Computer Scienc
Improving Peer-to-Peer Video Systems
No full textVideo Streaming is nowadays the Internet’s biggest source of consumer traffic. Traditional content providers rely on centralised client-server model for distributing their video streaming content. The current generation is moving from being passive viewers, or content consumers, to active content producers, and the traditional content distribution infrastructure needs to change and adapt. Peer-to-Peer (P2P) systems have proven to be a valuable solution for distributing content to a wide audience. However, they have been designed for file-sharing, and therefore require enhancements and modifications to fulfill the needs of video streaming distribution. In this thesis, we improve fully distributed P2P streaming systems through the design and evaluation of architectures and algorithms. We focus on three major challenges. First, we address the diversity of devices and connections in today’s Internet by describing the architecture for distributing multi bit-rate streaming content. Secondly, we present the design, implementation, and evaluation of a novel P2P streaming protocol specifically crafted to distribute streaming content. Finally, we provide a solution for increasing the privacy of P2P users without affecting their performance.PDSElectrical Engineering, Mathematics and Computer Scienc
Exploiting Graph Properties for Decentralized Reputation Systems
No full textIn online communities, users frequently interact with strangers in order to buy and sell products, watch videos, educating themselves, and playing games. Establishing trust among strangers is essential for the functionality of these communities but challenging, as well. Online reputation systems effectively establish trust among strangers by aggregating the history of user interactions in one reputation value per user. They differ from their offline counterparts in their large number of participants spread around the world, their explicit design, and the variety of defector strategies. This thesis studies reputation systems for decentralized networks such as distributed online social networks, online markets on mobile devices, and P2P networks. Due to the highly dynamic behavior of users and the scarcity of resources, several challenging scalability and security issues arise. To face these challenges, this thesis explores algorithms that exploit the graph structure induced by the user interactions in decentralized reputation systems. The socially rich available information of online communities allows the analysis of user behavior and its evolution over time. Using the key insights of this analysis, scalable and effective algorithms are designed in order to collect, store and aggregate information in decentralized reputation systems.Software TechnologyElectrical Engineering, Mathematics and Computer Scienc
Online Networks as Societies: User Behaviors and Contribution Incentives
No full textOnline networks like email, Facebook, LinkedIn, Wikipedia, eBay, and BitTorrent-like Peer-to-Peer (P2P) systems have become popular and powerful infrastructures for communication. They involve potentially large numbers of humans with their collective inputs and decisions, and they often rely on the cooperation and the contribution of their users. Nevertheless, users in online networks are often found to be selfish, strategic, or even malicious, rather than cooperative, and therefore they need to be incentivized for contributions. This thesis provides theoretical and practical insights into the correlation between user behaviors and contribution incentives in online networks. It contains a demonstration of user behaviors and their consequences at both the system and the individual level, an analysis of barter schemes and their limitations in incentivizing users to contribute, an evaluation of monetary schemes and their risks in causing the collapse of the entire system, and an examination of user interactions and their implications in inferring user relationships.Software and Computer TechnologyElectrical Engineering, Mathematics and Computer Scienc
Outsourcery: Simply extending home automation using plugins
No full textHomeWizard B.V. is looking to expand the range of compatible TCP/IP devices for its home automation hub. To this end, the company wants to use third-party plugins that control these devices. To allow even people with little programming experience to make devices compatible with the HomeWizard hub, these plugins have to be easy to create. These demands pose an interesting challenge: to create a system that is flexible enough to control hundreds of different devices, while being simple enough to be used by people with little programming experience. During the research phase of the project, existing home automation solutions were studied, as well as home automation techniques. The clients current position in the market was also researched to get a better understanding of the clients needs. During the implementation of the product, scrum was applied to manage the project. Prototypes were created in sprints of two weeks. A final prototype, called Outsourcery, is delivered at the end of the project. Outsourcery is a flexible home automation solution, facilitating the use of plugins to extend compatibility with both devices and network protocols. Outsourcery has been tested using unit tests and manual testing. An acceptance test determined that the creation of plugins is relatively easy. Outsourcery is a good start towards a universal home automation solution. However, it has still some way to go before it reaches maturity. Some required steps have been detailed in the report. Furthermore, some recommendations are done regarding the development of a plugin developer platform and making said platform available to customers.Bachelor Computer ScienceComputer ScienceElectrical Engineering, Mathematics and Computer Scienc
Power Management for Portable Devices
No full textElectrical Engineering, Mathematics and Computer Scienc
SwiftTV - Bringing 4th generation P2P to SmartTV
No full textSince their invention, TV's have become one of the most popular media devices and can be found in almost every livingroom in the world. For a long time, the functionality of the TV stayed the same: the ability to view television programs at certain fixed times of the day. Recently there has been development in the television market adding computing power and internet connectability to televisions. These new features open a whole new world of possibilities. The goal of this project was to create an application that runs on a Samsung SmartTV and uses the libswift peer-to-peer engine to download, upload and stream files. To create an application for a Samsung SmartTV a software development kit has been provided which allows programmers to create apps using JavaScript, HTML, CSS and Flash. This software development kit was used to create the front-end of our application. The front-end consists of an internal media player to handle streaming content and media playback found on an external USB device.Parallel and Distributed Systems GroupSoftware TechnologyElectrical Engineering, Mathematics and Computer Scienc
Tsukiji: A decentral market
No full textThis project creates a marketplace to trade commodities for real money. While many online marketplaces exist, they usually have one thing in common: a central point of authority. Our solution is Tsukiji, a completely decentralised marketplace, capable of scaling to thousands of users. Research has shown that implementations of this idea are scarce. Since the project is assigned by the group responsible for creating Tribler, this project follows their example in programming languages and libraries, such as Python and Twisted. Development of Tsukiji occurred in sprints of around 1 week, each sprint focusing on one or two specific features. Meetings with the product owner were planned after every development cycle, giving us feedback on the previous sprint and guiding the focus of the following sprint. The result is a light-weight, terminal-based, python application called Tsukiji. Users can post offers on the network and trade commodities for money. They communicate by sending messages using the gossip protocol, implemented with the Twisted library. Financial transactions are made using PayPal. With this, a fully decentralised market with a trustworthy payment system is created, allowing users to make trades without the risk of their trading platform being shut down.Parallel and Distributed SystemsElectrical Engineering, Mathematics and Computer Scienc
Autonomous Self-replicating Code
No full textDuring the project TENNET (the Tribler Exit Node NETwork) was constructed. A decentralized autonomously functioning agent that is capable of earning money by providing a Tribler exit node service. A Tribler exit node is a service used by Tribler (an anonymous file sharing platform) to be backwards compatible with torrents. TENNET will run this exit node on a server. It will then sell (what comes down to) Tribler upload capacity in exchange for Bitcoin. It will then use the gained bitcoin to buy a new VPS (Virtual Private Server) online, that it will install itself onto. From there, the cycle will continue, potentially resulting in a distributed network of Tribler exit nodes. During the development several prototypes and tests were constructed. * First prototype: buying a server and installing a new bitcoin wallet on this server fully automated. * Long term exit node test: running an exit node on multiple servers to see how they perform on different servers. * Second prototype: using a genetic algorithm, buy a server from the selection of VPS providers and install the agent on this together with a bitcoin wallet and Tribler exit node, then start all these services. * Third prototype: This was the finished product, capable of replicating and making money on it's own as well as the functionality of the second prototypeElectrical Engineering, Mathematics and Computer ScienceSoftware TechnologyDistributed System
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