367 research outputs found

    A new record of an interesting parasitic rotifer Balatro calvus Claparéde, 1867 in Hungary

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    Although widely distributed the parasitic rotifer Balatro calvus CLAPARÉDE, 1867 has only been sporadically observed. Here we document the presence of this species in enchytraeid (Annelida) specimens from different regions of Hungary

    NaMANET – Nagy kiterjedésű mobil ad hoc hálózatok vizsgálata = NaMANET - Investigation of Large-Scale Mobile Ad Hoc Networks

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    A NaMANET projekt keretében elsősorban a nagy kiterjedésű mobil ad hoc hálózatok, valamint a vezeték nélküli közösségi hálózatok témájával foglalkoztunk. A mobil ad hoc hálózatok közvetlen adatátvitelt biztosító kommunikációs megoldásokra épülő lokális hálózatok, míg a vezeték nélküli közösségi hálózatok ideális körülményeket nyújthatnak ad hoc alkalmazások implementálására és bevezetésére mintegy összekötő gerinchálózatot biztosítva a mobil ad hoc hálózati szigetek számára. Kutatásaink során modelleztük és szimulációk segítségével vizsgáltuk az alkalmazásterjedést nagy kiterjedésű ad hoc hálózatokban. Összehasonlítottuk különböző szolgáltatásmenedzsment architektúrák teljesítőképességét. Megvizsgáltuk különböző információterjesztési stratégiák hatékonyságát járművek alkotta ad hoc hálózatokban, valamint megvizsgáltunk különböző klaszterezési eljárásokat biztonság és megbízhatóság szempontjából szenzor hálózatokban. Foglalkoztunk okostelefonok ad hoc hálózatokban való használatával. Terveztünk és implementáltunk egy szolgáltatástámogatási keretrendszert demo alkalmazásokkal, valamint megvizsgáltuk az ad hoc hálózatok alkalmazhatóságának kérdéskörét beltéri navigációs rendszer esetén. Foglalkoztunk vezeték nélküli közösségi hálózatok tervezési, kiépítési, üzemeltetési kérdéseivel, továbbá kidolgoztunk egy link állapotváltozást előrejelző eljárást vezeték nélküli hálózatokra. Eredményeinket számos nemzetközi konferenciacikk, folyóiratcikk és könyvfejezet formájában publikáltuk. | In the NaMANET project, we mainly focused on the investigation of large-scale mobile ad hoc networks, and the field of wireless community networks. In mobile ad hoc networks, the mobile nodes close to each other can communicate directly with their neighbors, since wireless community networks can provide ideal conditions as a backbone of the ad hoc network islands for implementing and deploying ad hoc applications. In our research, we modeled and via simulations investigated application spreading in large-scale ad hoc networks. We compared the performance of different service management architectures. We investigated the efficiency of different message spreading strategies in vehicular ad hoc networks, moreover surveyed and analysed clustering algorithms and protocols used in sensor networks from the viewpoint of security and reliability. We also dealt with using smartphones in ad hoc networks. We developed and implemented a service provisioning framework for ad hoc networks together with some demo applications, and investigated the usability of ad hoc networks in indoor navigation. Furthermore, we dealt with the area of developing, deploying and maintaining wireless community networks, and developed a link state prediction algorithm for wireless networks. We published our results in several international conference papers, journal papers and book chapters

    Smart Timetable Service Based on Crowdsensed Data

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    The rapid technological development and the introduction of smart services make it possible for modern cities to offer an enhanced perception of city life for their inhabitants. For instance, a smart timetable service of the city’s public transportation lines updated in real-time can decrease unnecessary waiting times at stops and increase the efficiency of travel planning. However, the implementation of such a service in a traditional way requires the deployment and maintenance of some costly sensing and tracking infrastructure. Fortunately, mobile crowdsensing, when the crowd of passengers and their mobile devices are used to gather data, can be a viable and almost free of charge alternative for implementing sensing based smart city services. In this chapter, we put the emphasis on the introduction of a crowdsensing based smart timetable service, which has been developed as a prototype smart city application. The front-end interface of this service is called TrafficInfo. It is a simple and easy-to-use Android application which visualizes public transport information of the given city on Google Maps in real-time. The live updates of transport schedule information rely on the automatic stop event detection of public transport vehicles. TrafficInfo is built upon an Extensible Messaging and Presence Protocol (XMPP) based communication framework which was designed to facilitate the development of crowd assisted smart city applications. The chapter introduces this generic framework shortly, then describes the prototype smart timetable service

    Placement Optimization of Reference Sensors for Indoor Tracking

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    Efficient Event Detection in Public Transport Tracking

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    Abstract— Personal mobile devices are widespread and carried by their users most of the time over the day. Thanks to the integrated sensors they can report about visited places, movement types and speed of the users. However, efficient stopping event detection on public transport vehicles is still a challenge. These events, associated with the coordinates of real stations, can be useful to update public transit timetables according to real-time traffic. In field tests we evaluated the most commonly available suitable sensors’ precision and efficiency and developed our Stopping Event Detection Algorithm (SEDA), which utilizes only the accelerometer to find potential stopping times and the Wi-Fi sensor to validate or discard them by a novel localization method. Wi-Fi is used only 6.66% of the time of actual traveling on public vehicles. Our algorithm is shown to recognize properly 82.9-89.47% of public traffic stations while consuming daily only 13% the capacity of an average smartphone's battery

    A Publish-Subscribe Scheme Based Open Architecture for Crowd-Sourcing

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    Participatory sensing, when a crowd of users collaborate to collect useful information, based applications are getting popular these days thanks to the proliferation of powerful mobile devices. The built-in sensors of smartphones offer an easy and handy way to monitor the environment and collect data which can serve as the basis of smart applications. However, the quick and flexible development and deployment of these applications call for a unifying open architecture. In this paper we propose a publish-subscribe based open participatory sensing architecture

    Publish/Subscribe Communication for Crowd-sourcing Based Smart City Applications

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    Collecting data and monitoring our environment give the basis for smart city applications which are getting popular today. However, the traditional approach to deploy a sensing and monitoring infrastructure is usually expensive and not always practical. Mobile crowd-sourcing can open new ways for data collection and smart city services. In this case, mobile devices with their built-in sensors and their owners are used to monitor the environment. For instance, the timetable of a smart travel planner service can be updated in real-time based on the continuously monitored time gap by passengers between consecutive buses on a public transportation route. This requires a common communication model facilitating crowd-sourced data collection. In this paper, we overview the design considerations of crowd-sourcing based smart city applications, propose data collection via using the publish/subscribe communication model and investigate the possible use of the Extensible Messaging and Presence Protocol (XMPP) for such applications

    Evaluation of Simulation Engines for Crowdsensing Activities

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    The goal of this paper is to analyze existing simulation engines and assess how well-suited they are for simulating the formation, existence and dissolution of dynamic social networks, with a special emphasis on networks formed around crowdsensing efforts. The crowd in this context is a loosely-coupled social network of people, who use their mobile devices to collect and share data and receive some sort of service or satisfaction in return. Often it is hard to predict whether users would like a certain future crowdsensing application, therefore it is necessary to simulate the expected behavior of the crowd in a pre-specified simulation environment. This paper proposes an urban parking scenario, in which the drivers collect and share parking related events. The main part of this research is the analysis of three simulation engines, which will show which is the best suited for simulating dynamic social networks formed around crowdsensing efforts. The results will show that there are generic simulation environments capable of simulating large crowds, which also possess suitable visualization tools and integration with geospatial data
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