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Designing and implementing a web-based Network Controlling System (NCS) for automated real time routing service over the web, based on open source technologies: a case study for TehranSadidi, Javad 25 November 2013 (has links)
Nowadays, web-based applications are being developed every day. Web services play a main role in mutual information dissemination. Web-based routing services provide the possibility to use a routing service without needing to install professional spatial information software. Nor is it necessary to spend time gathering data, updating spatial data or running complicated algorithms. By using a web-based routing service, a client just opens a browser and defines the start and destination points. Then, the web-service can show the best route to the client. There are a number of free web-based routing services such as Google Maps, however, these services do not exploit a real time and dynamic routing services. The inability for current routing services to provide up to the second route information, offering automatic live correction with proprietary routing methods for classified users along with local database controlling facility for local administrators, can be a debilitating weakness for emergency and security personnel.
This research aims to develop current routing services to real time web-based service using open source technologies. The resulting program, Network Controlling System (NCS) updates and warns online users about closed or reopened parts of the network and corrects the found route whenever any update has happened. It is notable that all the mentioned processes happen automatically. NCS also exploits a live vectorial engine for segment controlling.
To implement and run the NCS, the following steps were taken:
• Running a simple routing service over the web according to the PgRouting project (FOSS4G2010) (http://pgrouting.org/) instruction
• Designing the conceptual architecture of the NCS
• Formulating the conceptual architecture to the programming codes
• Suggesting and evaluating new methods to offer real time capability to the routing system
• Integrating the NCS into the simple routing service
• Piloting the program in Tehran (capital of Iran)
After running a simple routing project without real time and controllable capabilities, the conceptual architecture of NCS was defined and programmed including the following components:
• A security protected administrator page as the entry web page for the administrator side.
• A text live search engine to search the target part of the network and submit updates.
• A vectorial search engine to find and locate the target part and its peripheral environment in larger scale of auxiliary information on other map servers like Google Maps/satellite/ terrain.
• Live vectorial warning to inform online users about closed parts and the ability to then re-open the after the closed street or segments.
• Live correction of the found route for online users. This facility would correct the found route whenever any update is happened for example a street or a subset of street is closed or reopened.
To program the conceptual architecture, the NCS was divided into two distinguishable parts: client-side and server-side. open source Technologies including open source Software and Open Standards web programming languages were used to program and run the model on the server. AJAX, JQuery, OpenLayers, GeoExt, ExtJS, JavaScript and HTML5 programming languages on the client-side along with PHP, SQL and PostGIS languages on the server-side were used to formulate the conceptual architecture of the NCS. GeoJSON and XML languages also work as exchange formats to act like brokers between the client and server-side. Ubuntu 12,04 (2013) was installed on the server as the platform and PostgreSQL server along with PostGIS and PgRouting extensions installed as relational database management system.
NCS integrated into the simple routing service offers designated real time service equipped with proprietary routing methods for classified users (from the simple routing service FOSSG2010 Pgrouting project), such as law officials and emergency personnel, who have authority to disregard traffic laws and restrictions.
To offer the routing live correction system in this research, three methods were designed, programmed and implemented. Then, a test was done to select the best method in which the least calculation capacity of the server is consumed. The evaluation results show that Check-Change-Correct method (designed and programmed for the first time in this research) imposes the least load average values to the server and subsequently, is able to serve more simultaneous users compare to other methods.
Finally, the research introduces a mobile controllable and real time routing service over the web, which can be used to decrease travelling time. This is very important in cities like Tehran, which suffers from a daily average of 182 accidents (http://www.jamejamonline.ir/ newstext.aspx, 28/3/ 2012), voice and chemical pollutions.
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Energy-efficient Real-time Coordination And Routing Framework For Wireless Sensor And Actor NetworksShah, Ghalib Asadullah 01 March 2007 (has links) (PDF)
In Wireless Sensor Actor Networks (WSANs), sensor nodes perform the sensing task and actor nodes take action based on the sensed phenomenon. The presence of actors in this configuration can not be benefited from, unless they are able to execute actions at right place and right time in the event region. The right place can be related to the accurate position of the sensor nodes. While, the right time is related to delivering the packets directly to the appropriate actors within the event specific response times. Hence, the efficient localization of sensor nodes, sensor-actor/actor-actor coordination and real-time routing is indispensable in WSANs. Furthermore, the limited energy levels and bandwidth of the state of art sensor nodes currently impose stringent requirements for low-complexity, low-energy, distributed coordination and cooperation protocols and their implementation.
In this study, we propose an integrated framework which addresses the issues of sensors localization, network configuration, data aggregation, real-time data delivery, sensor-actor/actor-actor coordination and energy saving mechanisms. The proposal incorporates novel approaches on three fronts / (1) timing-based sensors localization (TSL) algorithm to localize the sensor nodes relative to actors, (2) real-time coordination and routing protocols and (3) energy conservation. The distributed real-time coordination and routing is implemented in addressing and greedy modes routing. A cluster-based real-time coordination and routing (RCR) protocol operates in addressing mode. The greedy mode routing approach (Routing by Adaptive Targeting, RAT) is a stateless shortest path routing. In dense deployment, it performs well in terms of delay and energy consumption as compared to RCR.
To keep the traffic volume under control, the framework incorporates a novel real-time data aggregation (RDA) approach in RCR such that the packets deadlines are not affected. RDA is adaptive to the traffic conditions and provides fairness among the farther and nearer cluster-heads.
Finally, framework incorporates a power management scheme that eliminates data redundancy by exploiting the spatial correlation of sensor nodes.
Simulation results prove that the framework provides the real-time guarantees up to 95 % of the packets with lesser energy consumption of up to 33 % achieved using MEAC as compared to LEACH and SEP. The packet delivery ratio is also 60 % higher than that of semi-automated architecture. Furthermore the action accuracy is supported by TSL which restricts the localization errors less than 1 meter by tuning it according to the expected velocity of nodes and required accuracy.
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Optimisation du routage dans les réseaux de capteurs pour les applications temps-réel / Routing optimization in wireless sensor netwoks for real-time applicationsAissani, Mohamed 13 March 2011 (has links)
La résolution du problème des vides dans le routage géographique dédié aux réseaux de capteurs sans fil (RCS), rencontrés lors de la remontée des informations vers les nœuds collecteurs à partir des nœuds du réseau, constitue un verrou technologique qui reste un problème ouvert encore aujourd'hui. Cette thèse, contrairement aux méthodes traditionnelles, propose une nouvelle approche pour la prise en charge de ces vides tout en optimisant l'efficacité énergétique des nœuds déployés dans un RCS faisant ainsi du routage proposé une solution adéquate pour l'acheminement des informations en temps réel. Celui-ci se base sur l'information géographique concernant le nœud courant, les vides voisins et le nœud destinataire du paquet. Notre proposition agit aussi sur des mécanismes assurant la découverte, l'annonce et la maintenance des vides d'un RCS. Le premier protocole proposé, appelé VT-SPEED, est construit sur la base d'une fonction évolutive intégrant un mécanisme d'évitement adaptatif des vides et considérant simultanément la charge des nœuds candidats au routage et leur information géographique de localisation. Afin d'optimiser l'efficacité énergétique de VT-SPEED, notre proposition inclut par ailleurs de nouvelles routines sur la base de fonctions paramétriques pour la prise en compte de l'énergie dans le routage : (a) suppression des paquets retardés sur la base de leur échéance et (b) équilibrage de charge dans le choix des sauts des paquets. Les résultats enregistrés par le protocole résultant, appelé VE-SPEED, montrent que l'approche proposée prend en compte les flux de type temps-réel, possède une grande tolérance aux vides, conserve mieux l'énergie des nœuds de bordure, assure un meilleur équilibrage de charge, et consomme de manière optimisée l'énergie des nœuds capteurs / Resolution of the void-problem in geographical routing in Wireless Sensor Networks (WSN) is an open problem and it can be considered as key issue in disseminating data from sensor nodes to sinks. In this thesis, unlike previously-proposed methods, we address this problem in a different manner by proposing a novel approach to handle both voids and real-time flows with optimizing energy-efficiency of deployed nodes in a WSN. The proposed approach is based on the geographic information of the current node, of the neighbor voids and of the sink. Our proposal relies on the mechanisms that discover voids, announce them and then maintain them. The first proposed protocol, called VT-SPEED, is based on an adaptive void-avoidance mechanism that considers both load of routing candidate nodes and their localization information. To make VT-SPEED energy-aware, we also propose new routines based on parameterized functions that handle routing dissipation energy : (a) dropping out-of-order packets and (b) load-balancing when choosing next hop of packets. The resulting protocol, called VE-SPEED, has satisfactory results which show that the proposed approach satisfies the real-time constraints of data flows, tolerates voids, preserves energy resources of boundary nodes, balances load between nodes and has optimal energy consumption
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Mitigating Congestion by Integrating Time Forecasting and Realtime Information Aggregation in Cellular NetworksChen, Kai 11 March 2011 (has links)
An iterative travel time forecasting scheme, named the Advanced Multilane Prediction based Real-time Fastest Path (AMPRFP) algorithm, is presented in this dissertation. This scheme is derived from the conventional kernel estimator based prediction model by the association of real-time nonlinear impacts that caused by neighboring arcs’ traffic patterns with the historical traffic behaviors. The AMPRFP algorithm is evaluated by prediction of the travel time of congested arcs in the urban area of Jacksonville City. Experiment results illustrate that the proposed scheme is able to significantly reduce both the relative mean error (RME) and the root-mean-squared error (RMSE) of the predicted travel time. To obtain high quality real-time traffic information, which is essential to the performance of the AMPRFP algorithm, a data clean scheme enhanced empirical learning (DCSEEL) algorithm is also introduced. This novel method investigates the correlation between distance and direction in the geometrical map, which is not considered in existing fingerprint localization methods. Specifically, empirical learning methods are applied to minimize the error that exists in the estimated distance. A direction filter is developed to clean joints that have negative influence to the localization accuracy. Synthetic experiments in urban, suburban and rural environments are designed to evaluate the performance of DCSEEL algorithm in determining the cellular probe’s position. The results show that the cellular probe’s localization accuracy can be notably improved by the DCSEEL algorithm. Additionally, a new fast correlation technique for overcoming the time efficiency problem of the existing correlation algorithm based floating car data (FCD) technique is developed. The matching process is transformed into a 1-dimensional (1-D) curve matching problem and the Fast Normalized Cross-Correlation (FNCC) algorithm is introduced to supersede the Pearson product Moment Correlation Co-efficient (PMCC) algorithm in order to achieve the real-time requirement of the FCD method. The fast correlation technique shows a significant improvement in reducing the computational cost without affecting the accuracy of the matching process.
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