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1
Zinkhon, David C. "Undersea node localization using node-to-node acoustic ranges in a distributed Seaweb network". Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/March/09Mar%5FZinkhon.pdf.
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Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, March 2009.Thesis Advisor(s): Rice, Joseph A. "March 2009." Description based on title screen as viewed on April 24, 2009. Author(s) subject terms: Underwater acoustics, Seaweb, Localization, Difference linearization. Includes bibliographical references (p. 97-98). Also available in print.
2
Pandey, Santosh Agrawal Prathima. "Secure localization and node placement strategies for wireless networks". Auburn, Ala., 2007. http://hdl.handle.net/10415/1388.
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Kaiser, Tashniba. "Node Localization using Fractal Signal Preprocessing and Artificial Neural Network". WorldComp, International Conference on Security and Management, 2012, 2012. http://hdl.handle.net/1993/22730.
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This thesis proposes an integrated artificial neural network based approach to classify the position of a wireless device in an indoor protected area. Our experiments are conducted in two different types of interference affected indoor locations. We found that the environment greatly influences the received signal strength. We realized the need of incorporating a complexity measure of the Wi-Fi signal as additional information in our localization algorithm.
The inputs to the integrated artificial neural network were comprised of an integer dimension representation and a fractional dimension representation of the Wi-Fi signal. The integer dimension representation consisted of the raw signal strength, whereas the fractional dimension consisted of a variance fractal dimension of the Wi-Fi signal.
The results show that the proposed approach performed 8.7% better classification than the “one dimensional input” ANN approach, achieving an 86% correct classification rate. The conventional Trilateration method achieved only a 47.97% correct classification rate.
4
Pettersson, Christopher. "Automatic fault detection and localization in IPnetworks : Active probing from a single node perspective". Thesis, Linköpings universitet, Programvara och system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-120414.
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Fault management is a continuously demanded function in any kind of network management. Commonly it is carried out by a centralized entity on the network which correlates collected information into likely diagnoses of the current system states. We survey the use of active-on-demand-measurement, often called active probes, together with passive readings from the perspective of one single node. The solution is confined to the node and is isolated from the surrounding environment. The utility for this approach, to fault diagnosis, was found to depend on the environment in which the specific node was located within. Conclusively, the less environment knowledge, the more useful this solution presents. Consequently this approach to fault diagnosis offers limited opportunities in the test environment. However, greater prospects was found for this approach while located in a heterogeneous customer environment.
5
Lo, Geoffrey S. "Wireless body area network node localization using small-scale spatial information". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43256.
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Deploying wireless body area networks (WBANs) in the long-term at-home monitoring of a patient’s physiological and bio-kinetic conditions has become increasingly prevalent. However, such WBANs do not typically incorporate mechanisms to detect and correct for the possibility of accidentally switching up wearable wireless sensor nodes (W²SNs), where a node assigned to one limb is placed on another, and vice-versa, leading to possible incorrect prognoses from interpreting the data.
In this thesis, we present a new scheme to automatically identify and verify the locations of W²SNs in a WBAN. Using small-scale geospatial information, instantaneous atmospheric air pressures at each node are examined and compared to map and match them in physical space. By enhancing the context-awareness of WBANs, this enhancement enables unassisted sensor node placement, providing a practical solution to obtain and continuously monitor node locations at a sufficient resolution to recognize limb placement, without multidimensional fine-grain position information. Only a single atmospheric air pressure sensor (A²PS) is added to each W²SN; compared to existing localization techniques, no beacons or extra nodes are required, enabling an inexpensive and self-contained solution.
To quantify and validate the accuracy, consistency and reliability of this localization scheme, a statistical analysis on a set of commercially-available air pressure sensors and an experimental prototype WBAN is conducted to examine the scheme’s performance and limitations. This study has verified that this approach is indeed capable of distinguishing between positions indicative of expected separation between different limbs of the patient’s body. Based on a 60cm separation between nodes, the statistical analysis consistently exceeded 95% accuracy within the confidence interval (CI), demonstrating great promise for incorporation into commercial WBANs.
We also present and experimentally demonstrate an enhancement aiming to reduce false-positive (Type I) errors in conventional accelerometer-based on-body fall detection schemes. Our statistical analysis has shown that by continuously monitoring the patient’s limb positions, the W²SN position information would enable the WBAN to better classify ‘fall-like’ motion from actual falls, where the patient requires remote caregiver assistance.
6
Dong, Shaoqiang Agrawal Prathima. "Node placement, routing and localization algorithms for heterogeneous wireless sensor networks". Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Electrical_and_Computer_Engineering/Thesis/Dong_Shaoqiang_40.pdf.
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Smolau, Siarhei. "Evaluation of the Received Signal Strength Indicator for Node Localization in Wireless Sensor Networks". Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26078/26078.pdf.
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A wireless sensor network (WSN) consists of a large number of sensor nodes that are
capable of detecting many types of information from the environment, including temperature,
light, humidity, radiation and seismic vibrations. Current applications of
WSNs include: physical security, air traffic control, video surveillance, environment
and building monitoring. Such applications require that each sensor node knows its exact
location. In this context, the received signal strength indicator (RSSI) is often used
for distance measurements between the sensor nodes. This thesis presents a method
for the evaluation of the RSSI properties in application to node localization in WSN.
More specifically, a WSN application is implemented for collecting RSSI measurement
in different conditions. The application consists of two parts: an experiment control
script which runs on a computer, and an experiment mote firmware which runs on
each WSN node. Statistical analysis of variance (ANOVA) was performed to determine
the factors affecting the RSSI measurements. Result analysis shows that: the relation
between RSSI values and distances depends on the environment; the used WSN
motes are manufactured with enough precision, as the differences between the motes
are insignificant; even if the RSSI measurements have significant variation, the mean
RSSI values correlate with the distances; using different transmission power levels can
provide additional information about the distances.
8
Vícha, Tomáš. "Lokalizace objektů v prostředí bezdrátové senzorové sítě". Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2021. http://www.nusl.cz/ntk/nusl-445530.
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This thesis deals with the use of spatial awareness methods within technologies designed for creation of short-range wireless sensor networks. The thesis analyzes several techniques that can be used to estimate position of objects within the sensor network. For a practical solution, a method based on measuring the time differences of the sent messages was chosen. A circuit implementation of a network node based on the DW1000 chip, which works on ultra-wideband transmission technology, was implemented. A sensor network with the appropriate user application for its operation and display of localization results was also implemented.
9
Martynek, Tomáš. "Implementace bezkotevní lokalizační techniky do simulačního prostředí ns2". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218279.
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This thesis deals with the issue of localization in wireless sensor networks. It focuses on the implementation Anchor-Free localization techniques to NS2 and evaluation of its effectiveness. In the theoretical introduction is summarized IEEE802.15.4 and ZigBee technology. The following chapter describes the Anchor-Based and Anchor-Free localization methods. Furthermore, existing methods of measuring the distance of network nodes are described. Also pay attention NS2 environment, especially the inclusion of standard IEEE802.15.4. The section devoted to Anchor-Free algorithm describes how to search and select anchor modes. It also described the method of optimization by measuring the distance of neighboring nodes using the Mass-Spring Algorithm. Next chapter describe the inclusion of a new protocol called AFLOCAL into NS2 and detailed analysis of its function. Next described the process of localization and calculating the coordinates. Described was aslo a method of simulation and evaluation of results. In conclusion, the results are summarized and formulated the characteristics of designed protocol AFLOCAL.
10
Maňák, Jiří. "Energetická náročnost lokalizačních algoritmů". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219344.
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This masters thesis deals with technics of localization for wireless senzor networks with a focus on anchor free location algorithm by authors G. Jianquan and Z. Wei. It also describes the available simulations frameworks based on OMNeT++ platform and implementation of the anchor free algorithm in the simulation program Castalia. Furthermore, it deals with the energy demands of this algorithm based on results of simulations that were done for the communication unit IRIS.
11
Pasupathy, Karthikeyan. "Anchor Nodes Placement for Effective Passive Localization". Thesis, University of North Texas, 2010. https://digital.library.unt.edu/ark:/67531/metadc33132/.
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Wireless sensor networks are composed of sensor nodes, which can monitor an environment and observe events of interest. These networks are applied in various fields including but not limited to environmental, industrial and habitat monitoring. In many applications, the exact location of the sensor nodes is unknown after deployment. Localization is a process used to find sensor node's positional coordinates, which is vital information. The localization is generally assisted by anchor nodes that are also sensor nodes but with known locations. Anchor nodes generally are expensive and need to be optimally placed for effective localization. Passive localization is one of the localization techniques where the sensor nodes silently listen to the global events like thunder sounds, seismic waves, lighting, etc. According to previous studies, the ideal location to place anchor nodes was on the perimeter of the sensor network. This may not be the case in passive localization, since the function of anchor nodes here is different than the anchor nodes used in other localization systems. I do extensive studies on positioning anchor nodes for effective localization. Several simulations are run in dense and sparse networks for proper positioning of anchor nodes. I show that, for effective passive localization, the optimal placement of the anchor nodes is at the center of the network in such a way that no three anchor nodes share linearity. The more the non-linearity, the better the localization. The localization for our network design proves better when I place anchor nodes at right angles.
12
Kothapalli, Hindu. "Localization of nodes in wired and wireless networks". Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Kothapalli_09007dcc806b7c59.pdf.
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Thesis (M.S.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 25, 2009) Includes bibliographical references.
13
Švéda, Jaroslav. "Nalezení pozice stanic v Internetu pomocí umělých souřadnicových systémů". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218001.
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This thesis deals with predicting the latency between two network nodes, such as the two stations, two servers or server and station. The main reason for adoption of effective latency prediction techniques is the elimination of network load caused by unnecessary repeated transmissios or by direct measurement of the latency. Of the many proposed methods of latency estimation, this thesis is focused on methods using artificial coordinate systems with primary focus on the Vivaldi algorithm. Characteristics of the latency prediction methods and properties of various coordinate systems used in practice are evaluated. The issue of the number of dimensions of space defined only by the latency matrix between nodes is also mentioned. Furthermore, some other systems, based on logical clustering of nearby nodes, are mentioned. Description of simulation software VivaldiMonitor developed as part of the thesis is included. The primary purpose is analysis of the behavior of overlay networks implementing Vivaldi algorithm with less than a few hundred nodes. The Vivaldi algorithm is assessed by several simulations carried out using the aforementioned software.
14
Ash, Joshua N. "On singular estimation problems in sensor localization systems". Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196221762.
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Tao, Qian. "Cellular localization and gene expression of epstein-barr virus in non-neoplastic nasal mucosa and nasal lymphoma /". Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17538828.
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López, Villafuerte Freddy [Verfasser]. "Localization of wireless sensor nodes based on local network density / Freddy López Villafuerte". Berlin : Freie Universität Berlin, 2010. http://d-nb.info/1024104060/34.
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Zandian, Reza [Verfasser]. "Ultra-wideband Based Indoor Localization of Mobile Nodes in ToA and TDoA Configurations / Reza Zandian". Bielefeld : Universitätsbibliothek Bielefeld, 2019. http://d-nb.info/119663985X/34.
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Hedges, Mitchell Lawrence. "An investigation into the use of intuitive control interfaces and distributed processing for enhanced three dimensional sound localization". Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/d1020615.
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This thesis investigates the feasibility of using gestures as a means of control for localizing three dimensional (3D) sound sources in a distributed immersive audio system. A prototype system was implemented and tested which uses state of the art technology to achieve the stated goals. A Windows Kinect is used for gesture recognition which translates human gestures into control messages by the prototype system, which in turn performs actions based on the recognized gestures. The term distributed in the context of this system refers to the audio processing capacity. The prototype system partitions and allocates the processing load between a number of endpoints. The reallocated processing load consists of the mixing of audio samples according to a specification. The endpoints used in this research are XMOS AVB endpoints. The firmware on these endpoints were modified to include the audio mixing capability which was controlled by a state of the art audio distribution networking standard, Ethernet AVB. The hardware used for the implementation of the prototype system is relatively cost efficient in comparison to professional audio hardware, and is also commercially available for end users. the successful implementation and results from user testing of the prototype system demonstrates how it is a feasible option for recording the localization of a sound source. The ability to partition the processing provides a modular approach to building immersive sound systems. This removes the constraint of a centralized mixing console with a predetermined speaker configuration.
19
Kadlubiec, Janusz. "Dlouhodobé posuzování vozovek opravených recyklací podkladů". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225491.
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My work deals with monitoring communications sections, which were renovated zrecyklováním existing surface. I documented these communications and to assess their condition after the time of use. Subscribed sections I put into the database PMS.
20
Rosen, Gail L. "Signal processing for biologically-inspired gradient source localization and DNA sequence analysis". Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-07102006-123527/.
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Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2007.Oliver Brand, Committee Member ; James H. McClellan, Committee Member ; Paul Hasler, Committee Chair ; Mark T. Smith, Committee Member ; David Anderson, Committee Member.
21
Shen, Guowei [Verfasser], Reiner [Akademischer Betreuer] Thomä, Jörn [Gutachter] Thielecke y Günther [Gutachter] Schäfer. "Localization of Active Nodes within Distributed UWB Sensor Networks in Multipath Environments / Guowei Shen ; Gutachter: Jörn Thielecke, Günther Schäfer ; Betreuer: Reiner Thomä". Ilmenau : TU Ilmenau, 2012. http://d-nb.info/1178185621/34.
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Tautenhahn, Martin y Ivan Veselic'. "A note on correlated and non-monotone Anderson models". Universitätsbibliothek Chemnitz, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200800063.
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Pekárek, Jan. "Snížení chyby odhadu pozice u inkrementálních lokalizačních technik". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-218822.
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The diploma thesis describes localization of communications nodes in the Wireless Sensor Networks. This thesis contains basic algorithms for localization sensor's nodes as are Map-Growing and ABC (Assumption Based Coordinates). Then is chosen acceptable algorithm for simulation on random sensor networks. For research these problems is used software MATLAB. For a given the university's environment are researched appropriate algorithms with possible optimalization algorithms. The result of diploma thesis is a localization algorithm with initial multilateration system and this system is located in the center sensor's network. As algorithm IMap4-Growing (Improved Map4-Growing) with optimization, which uses optimization distance between sensors and radio range. In the diploma thesis is simulated optimalization algorithm Mass-Spring.
24
Shah, Ghalib Asadullah. "Energy-efficient Real-time Coordination And Routing Framework For Wireless Sensor And Actor Networks". Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608239/index.pdf.
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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.
25
Barlas, Marios Dimitrios. "Development and characterization of innovative nonvolatile OxRAM memory cells compatible with advanced nodes". Electronic Thesis or Diss., Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0229.
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La mémoire résistive à la base des oxydes de transition métallique (ReRAM) est une classe de technologies de mémoire non volatile dans lesquelles la commutation entre états de mémoire est rendue possible par la décomposition réversible de l’oxyde au moyen de la création et de la dissolution d’un chemin de percolation (filament). Les principaux avantages de cette technologie résident dans l’évolutivité de la cellule de mémoire, principalement en raison de la dimension inférieure à 10 nm du filament, de sa faible consommation d’énergie (<300 pJ / commutateur) et de la compatibilité des matériaux avec la technologie CMOS avancée. Néanmoins, deux obstacles majeurs ont jusqu'à présent empêché la mise en œuvre de ReRAM dans les réseaux de grande taille: premièrement, la nécessité d'une tension de claquage initiale supérieure à la tension de fonctionnement et, deuxièmement, les composantes de variabilité intrinsèque et extrinsique résultant de l'interaction des matériaux à son environnement ainsi qu’à la nature stochastique fondamentale de la conduction percolative. Ce travail est axé sur la technologie ReRAM à base de HfO2. D'abord, des alliages d'HfO2 sont étudiés. Dans la seconde partie, l’alliage HfSiOx proposé est intégré dans le BEOL d’un procédé de 130 nm et l’impact de l’intégration de la zone de commutation dans la formation, la commutation, l’évolution du taux d’erreur et la conservation des données est étudié. Dans la dernière partie, une intégration basée sur HfO2 dans le MOL ancien d’un processus CMOS FDSOI 300 mm avancé est étudiée, qui étudie les performances et les limitations standard de HfO2 ReRAMTransition Metal Oxide ReRAM is a class of non-volatile memory technologies where the switching between memory states is enabled by the reversible breakdown of the oxide by means of the creation and dissolution of a percolation path (filament). The main advantages of the technology lie in the scalability of the memory cell –mainly owed to the sub 10nm dimension of the filament, its low power consumption (< 300 pJ/ switch) and material compatibility to advanced CMOS. Nevertheless, there are two major roadblocks that have prevented so far the implementation of ReRAM in large arrays: first, the requirement for an initial breakdown happening voltages significantly higher than the operating voltage range and second, the intrinsic and extrinsic variability components arising from material interaction to its environment as well as the fundamental stochastic nature of percolative conduction. This work, is focused on HfO2 based ReRAM technology. In the first part, we investigate different dopants to engineer the conductive properties of HfO2 by combining a first-principles approach and in-depth material characterization techniques. In the second part, the proposed HfSiOx alloy is integrated in the BEOL of a 130nm process and the impact of the integration of the switching zone in forming, switching, error rate evolution and data retention is investigated. In the last part, a HfO2 based integration in the early MOL of an advanced FDSOI 300mm CMOS process is demonstrated investigating standard HfO2 ReRAM performances and limitations
26
Ben, Zid Maha. "Emploi de techniques de traitement de signal MIMO pour des applications dédiées réseaux de capteurs sans fil". Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENT017/document.
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Dans ce travail de thèse, on s'intéresse é l'emploi de techniques de traitement de signal de systèmes de communication MIMO (Multiple Input Multiple Output) pour des applications aux réseaux de capteurs sans fil. Les contraintes énergétiques de cette classe de réseau font appel à des topologies particulières et le réseau peut être perçu comme étant un ensemble de grappes de nœuds capteurs. Ceci ouvre la porte à des techniques avancées de communication de type MIMO. Dans un premier temps, les différents aspects caractérisant les réseaux de capteurs sans fil sont introduits. Puis, les efforts engagés pour optimiser la conservation de l'énergie dans ces réseaux sont résumés. Les concepts de base de systèmes MIMOs sont abordés dans le deuxième chapitre et l'exploration par voie numérique de différentes pistes de la technologie MIMO sont exposées. Nous nous intéressons à des techniques de diversité de polarisation dans le cadre de milieux de communication riches en diffuseurs. Par la suite, des méthodes de type beamforming sont proposées pour la localisation dans les réseaux de capteurs sans fil. Le nouvel algorithme de localisation est présenté et les performances sont évaluées. Nous identifions la configuration pour la communication inter-grappes qui permet pour les meilleurs compromis entre énergie et efficacité spectrale dans les réseaux de capteurs sans fil. Finalement, nous envisageons la technique de sélection de nœuds capteurs afin de réduire la consommation de l'énergie dans le réseau de capteur sans filThe aim of this work is to study from a signal processing point of view the use of MIMO (Multiple Input Multiple Output) communication systems for algorithms dedicated to wireless sensor networks. We investigate energy-constrained wireless sensor networks and we focus on cluster topology of the network. This topology permits for the use of MIMO communication system model. First, we review different aspects that characterize the wireless sensor network. Then, we introduce the existing strategies for energy conservation in the network. The basic concepts of MIMO systems are presented in the second chapter and numerical results are provided for evaluating the performances of MIMO techniques. Of particular interest, polarization diversity over rich scattering environment is studied. Thereafter, beamforming approach is proposed for the development of an original localization algorithm in wireless sensor network. The novel algorithm is described and performances are evaluated by simulation. We determine the optimal system configuration between a pair of clusters that permits for the highest capacity to energy ratio in the fourth chapter. The final chapter is devoted to sensor nodes selection in wireless sensor network. The aim of using such technique is to make energy conservation in the network
27
Tsai, Yi-Jhong y 蔡逸鐘. "Node Deployment Strategy for WSN-based Node-Sequence Localization". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/33913310477883604395.
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碩士龍華科技大學
電機工程研究所
99
In this thesis we focus on the research of deployment strategy of sensor nodes for Wireless Sensor Network (WSN) for localization based on node-sequence algorithm. To investigate the effects of locations of deployed sensor nodes on the location errors, we have first developed a node deployment tool kit for node-sequence localization. Based on the experience via the tool kit we then develop our node deployment methodologies. The node deployment strategy can be divided into two large categories depending on whether path of target movement is taken into consideration. (1) When not considering the path, deployment methods such as maintaining spacing between nodes, optimization with standard deviation of area of space cut by perpendicular bisectors, and optimization with the angle between perpendicular bisectors can be utilized to improve location errors. (2) When the path is taken into consideration, according to different path conditions the path can be first segmented and then processed with node surrounding algorithm with analysis on the impact of locations of deployed nodes on the location errors. Evaluation and analysis have also been conducted via ns2 network simulator. In the ns2 simulation the location estimation of the target can be derived via EKT distance. When EKT distance is 0, the target location can be estimated as the center of gravity of the polygon of the direct matched node sequence. When EKT distance is not 0 in cases such as not all node sequences can be gathered, node location can be estimated by searching for the location with minimal EKT distance in the neighboring polygons. In the simulation, we have also investigated the trend and the effect of node transmission range and sampling distance on the location errors. The evaluation results via ns2 simulation have shown that our node deployment strategy can be effective in reducing location error either with or without consideration of moving paths for node-sequence localization based on wireless sensor networks.
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Stoleru, Radu. "Robust node localization for wireless sensor networks /". 2007. http://wwwlib.umi.com/dissertations/fullcit/3280013.
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Oanh, Sai Van y 蔡文鶯. "Node Localization in Wireless Sensor Networks with Heuristic Optimization Methods". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/35824456358796780306.
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碩士國立高雄應用科技大學
電子工程系碩士班
104
In Wireless Sensor Networks, the precision of sensor nodes localization will directly affect to perform of WSNs in almost of applications. Therefore, localization problem is a very important work. Localization algorithm will help the network know about the position of unknown sensor nodes based on the location of anchors. Some heuristic optimization algorithms are being proposed and succeeded in applying to solve localization problems in Wireless Sensor Networks. In this context, the performance of these heuristic optimization algorithms in solving localization problem of WSNs and nonlinear functions in both of accuracy and execution time will be compared. An improvement in localization algorithm call Extended Localization Algorithm (ELA) also will be proposed to enhance the number of a node can be localized. This improvement is really potential to extend and apply in many problems of WSN that is related to localization algorithms.
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Huang, Sung-Sheng y 黃頌升. "Mobile Sensor Node Localization and Path Planning for Wireless Sensor Network". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/30328447555805168305.
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碩士國立中正大學
光機電整合工程所
96
Sensor network is composed of many sensor nodes and its characteristics including low power consumption, low cost, high precision and so on. Sensor nodes have processing data, communication, and receive data capability. But a common design of sensor nodes lacks of mobility, the application have greatly limitation. In this thesis, we design and implement a mobile sensor node. In order to apply indoor service for mobile sensor node, we develop an indoor localization system and propose a path planning algorithm. We use wireless LAN medium (Zigbee) to implement. However radio signal propagation is easily affected by obstacles that cause diffraction, reflections, scattering and multi-path in the building. In order to reduce the measurement error of RSS value we firstly utilize Kalman filter theory. Then we fuse RSS and Dead-Reckoning system by using CI (Covariance Intersection) theory to get more accuracy of localization. Using dynamic triangular localization method we can get the coordination of mobile sensor node. The average mean distance error is between 0.8 and 1m. In general, aging and children care problem will have great impact on our country. Our mobile sensor node also can apply for home care. When emergency situation occur, we can get the coordination of children and elder through indoor localization system. Mobile sensor node will find a path and move to accident place by path planning algorithm. It will also send a message to medical staff. We also develop remote control technology to know information well continuously.
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Chenji, Jayanth Harshavardhan. "A Fuzzy Logic-Based Approach for Node Localization in Mobile Sensor Networks". 2009. http://hdl.handle.net/1969.1/ETD-TAMU-2009-12-7510.
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In most range-based localization methods, inferring distance from radio signal
strength using mathematical modeling becomes increasingly unreliable and complicated
in indoor and extreme environments, due to effects such as multipath propagation
and signal interference. We propose FuzLoc, a range-based, anchor-based,
fuzzy logic enabled system system for localization. Quantities like RSS and distance
are transformed into linguistic variables such as Low, Medium, High etc. by binning.
The location of the node is then solved for using a nonlinear system in the fuzzy
domain itself, which outputs the location of the node as a pair of fuzzy numbers. An
included destination prediction system activates when only one anchor is heard; it
localizes the node to an area. It accomplishes this using the theoretical construct of
virtual anchors, which are calculated when a single anchor is in the node’s vicinity.
The fuzzy logic system is trained during deployment itself so that it learns to
associate an RSS with a distance, and a set of distances to a probability vector.
We implement the method in a simulator and compare it against other methods like
MCL, Centroid and Amorphous. Extensive evaluation is done based on a variety of
metrics like anchor density, node density etc.
32
Chang, Han-Ming y 張漢民. "Localization Mechanism with Mobile Reference Node in Grid-based Wireless Sensor Networks". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/83019888458665286461.
Texto completoResumen
碩士淡江大學
資訊工程學系碩士班
100
Wireless sensor network applications are based on monitoring or managing the sensing area by using the location information with sensor nodes. These sensor nodes are random deployed, so they have to be aware to their location before starting their tasks. Most sensor nodes need hardware support or receive packets with location information to estimate their location, and needs lots of time or costs. It may have a huge error. In this thesis we present a localization mechanism in wireless sensor networks. This mechanism can cooperate with node localization algorithm and mobile reference node moving direction scheme. We use a mobile reference node with GPS to move to the whole environment, and we use RSSI and trilateration to estimate unknown nodes’ location. We can obtain more unknown nodes location by mobile reference node moving. It decreases the energy consumption and average location error.
33
Chang, Chi-Yu y 張圻毓. "The Study of Relay Node Placement and Localization Problems in Wireless Sensor Networks". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/22483516411275875958.
Texto completoResumen
博士義守大學
資訊工程學系
102
In the thesis, we propose a linear time approximation algorithm for the minimum geometric disk cover (MGDC) problem in wireless sensor networks (WSNs). The proposed algorithm can be applied to the relay node placement problem of wireless sensor networks. Given a set P with n points in the Euclidean plane, the MGDC problem is to identify the smallest set of congruent disks with prescribed radius r that covers all points in P. It is known that the MGDC problem is NP-complete. A novel linear time approximation algorithm for the MGDC problem is proposed, which identifies covering disks using the regular hexagon tessellation of the plane. The approximation ratio of the proposed algorithm is (5+ϵ), where 0<ϵ≤15. Experiment results show that the worst case is rare, and on average, the proposed algorithm uses less than 1.7 times the optimal disks of the MGDC problem. Suppose in a WSN, the deployed relay nodes are homogeneous, and their communication ranges are circles with radius r, the WSN relay node placement problem can be resolved by first solving the MGDC problem and placing the relay nodes at the centers of the covering disks, and then, if necessary, deploying additional relay nodes to meet the connection requirement of relay nodes. For the case that needs to promptly deploy the relay nodes, this study provides a fast 7-approximation algorithm which uses on average less than twice the optimal number of relay nodes in the experiments. For the localization problem of the WSNs, we presents a low-cost yet effective scheme which uses only two anchor nodes and uses bilateration to estimate the coordinates of unknown nodes. Many localization algorithms of WSNs require the installation of extra components, such as a GPS, ultrasonic transceiver, and unidirectional antenna. The proposed localization scheme is range-free (i.e., not demanding any extra devices for the sensors). In this scheme, two anchor nodes are installed at the bottom-left corner (Sink X) and the bottom-right corner (Sink Y) of a square monitored region of the WSN. Sensors are identified with the same minimum hop counts pair to Sink X and Sink Y to form a zone, and the estimated location of each unknown sensor is adjusted according to its relative position in the zone. This study compares the proposed scheme with the well-known DV-Hop method. Simulation results show that the proposed scheme outperforms the DV-Hop method in localization accuracy, communication cost, and computational complexity.
34
Ahmad, Aitzaz 1984. "Timing Synchronization and Node Localization in Wireless Sensor Networks: Efficient Estimation Approaches and Performance Bounds". Thesis, 2012. http://hdl.handle.net/1969.1/148131.
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Wireless sensor networks (WSNs) consist of a large number of sensor nodes, capable of on-board sensing and data processing, that are employed to observe some phenomenon of interest. With their desirable properties of flexible deployment, resistance to harsh environment and lower implementation cost, WSNs envisage a plethora of applications in diverse areas such as industrial process control, battle- field surveillance, health monitoring, and target localization and tracking. Much of the sensing and communication paradigm in WSNs involves ensuring power efficient transmission and finding scalable algorithms that can deliver the desired performance objectives while minimizing overall energy utilization. Since power is primarily consumed in radio transmissions delivering timing information, clock synchronization represents an indispensable requirement to boost network lifetime. This dissertation focuses on deriving efficient estimators and performance bounds for the clock parameters in a classical frequentist inference approach as well as in a Bayesian estimation framework.
A unified approach to the maximum likelihood (ML) estimation of clock offset is presented for different network delay distributions. This constitutes an analytical alternative to prior works which rely on a graphical maximization of the likelihood function. In order to capture the imperfections in node oscillators, which may render a time-varying nature to the clock offset, a novel Bayesian approach to the clock offset estimation is proposed by using factor graphs. Message passing using the max-product algorithm yields an exact expression for the Bayesian inference problem. This extends the current literature to cases where the clock offset is not deterministic, but is in fact a random process.
A natural extension of pairwise synchronization is to develop algorithms for the more challenging case of network-wide synchronization. Assuming exponentially distributed random delays, a network-wide clock synchronization algorithm is proposed using a factor graph representation of the network. Message passing using the max- product algorithm is adopted to derive the update rules for the proposed iterative procedure. A closed form solution is obtained for each node's belief about its clock offset at each iteration.
Identifying the close connections between the problems of node localization and clock synchronization, we also address in this dissertation the problem of joint estimation of an unknown node's location and clock parameters by incorporating the effect of imperfections in node oscillators. In order to alleviate the computational complexity associated with the optimal maximum a-posteriori estimator, two iterative approaches are proposed as simpler alternatives. The first approach utilizes an Expectation-Maximization (EM) based algorithm which iteratively estimates the clock parameters and the location of the unknown node. The EM algorithm is further simplified by a non-linear processing of the data to obtain a closed form solution of the location estimation problem using the least squares (LS) approach. The performance of the estimation algorithms is benchmarked by deriving the Hybrid Cramer-Rao lower bound (HCRB) on the mean square error (MSE) of the estimators.
We also derive theoretical lower bounds on the MSE of an estimator in a classical frequentist inference approach as well as in a Bayesian estimation framework when the likelihood function is an arbitrary member of the exponential family. The lower bounds not only serve to compare various estimators in our work, but can also be useful in their own right in parameter estimation theory.
35
Mwila, Martin K. "An efficient approach for node localisation and tracking in wireless sensor networks". 2014. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001800.
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M. Tech. Electrical Engineering.Objectives of this research is to use the node orientation, coupled with antenna radiation pattern of each node, to improve the Received Signal Strength (RSS) range measurement technique. As energy eciency is critical to WSNs, it is necessary to minimize both computation and communication costs in any operation involving WSNs,including during the localisation process. To achieve that, accelerometer measurements are used to reduce the number of iteration of the optimisation process during the refinement phase by computing more accurately an initial position for the optimisation using dead reckoning and approach the localisation in a distributed manner. The contribution of this is the investigation and development of an ecient localisation algorithm that can be used on a low cost wireless sensor board developed using existing technology. A review of the existing methods is conducted to highlight the key aspect to consider when developing an ecient localisation algorithms. A mathematical modelling of the proposed algorithm is developed and simulation is conducted to analyse the performance of the algorithm. An exhaustive test bed hardware has been designed on which the algorithm can to be validated.
36
Liu, Hsi. "Antigen specific lymphocyte localization effect of recent Brucella abortus challenge on lymphocytes from a previously challenged lymph node, analysis by flourescent labelling and flow cytometry /". 1985. http://catalog.hathitrust.org/api/volumes/oclc/12777097.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1985.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 27-29).
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Vales, Ruben Oliveira. "Nomadic fog storage". Master's thesis, 2017. http://hdl.handle.net/10071/14930.
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Mobile services incrementally demand for further processing and storage. However,
mobile devices are known for their constrains in terms of processing, storage, and energy.
Early proposals have addressed these aspects; by having mobile devices access remote
clouds. But these proposals suffer from long latencies and backhaul bandwidth limitations
in retrieving data. To mitigate these issues, edge clouds have been proposed. Using this
paradigm, intermediate nodes are placed between the mobile devices and the remote
cloud. These intermediate nodes should fulfill the end users’ resource requests, namely
data and processing capability, and reduce the energy consumption on the mobile devices’
batteries.
But then again, mobile traffic demand is increasing exponentially and there is a greater
than ever evolution of mobile device’s available resources. This urges the use of mobile
nodes’ extra capabilities for fulfilling the requisites imposed by new mobile applications.
In this new scenario, the mobile devices should become both consumers and providers of
the emerging services. The current work researches on this possibility by designing,
implementing and testing a novel nomadic fog storage system that uses fog and mobile
nodes to support the upcoming applications. In addition, a novel resource allocation
algorithm has been developed that considers the available energy on mobile devices and
the network topology. It also includes a replica management module based on data
popularity. The comprehensive evaluation of the fog proposal has evidenced that it is
responsive, offloads traffic from the backhaul links, and enables a fair energy depletion
among mobiles nodes by storing content in neighbor nodes with higher battery autonomy.Os serviços móveis requerem cada vez mais poder de processamento e armazenamento. Contudo, os dispositivos móveis são conhecidos por serem limitados em termos de armazenamento, processamento e energia. Como solução, os dispositivos móveis começaram a aceder a estes recursos através de nuvens distantes. No entanto, estas sofrem de longas latências e limitações na largura de banda da rede, ao aceder aos recursos. Para resolver estas questões, foram propostas soluções de edge computing. Estas, colocam nós intermediários entre os dispositivos móveis e a nuvem remota, que são responsáveis por responder aos pedidos de recursos por parte dos utilizadores finais. Dados os avanços na tecnologia dos dispositivos móveis e o aumento da sua utilização, torna-se cada mais pertinente a utilização destes próprios dispositivos para fornecer os serviços da nuvem. Desta forma, o dispositivo móvel torna-se consumidor e fornecedor do serviço nuvem. O trabalho atual investiga esta vertente, implementado e testando um sistema que utiliza dispositivos móveis e nós no “fog”, para suportar os serviços móveis emergentes. Foi ainda implementado um algoritmo de alocação de recursos que considera os níveis de energia e a topologia da rede, bem como um módulo que gere a replicação de dados no sistema de acordo com a sua popularidade. Os resultados obtidos provam que o sistema é responsivo, alivia o tráfego nas ligações no core, e demonstra uma distribuição justa do consumo de energia no sistema através de uma disseminação eficaz de conteúdo nos nós da periferia da rede mais próximos dos nós consumidores.
38
Wei, Ying-Feng y 魏瀅峰. "Relative-Localization Identification of Random DistributedWireless Sensor Network Nodes". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/68279857056479752441.
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碩士臺灣大學
工程科學及海洋工程學研究所
98
In the past few years, localization technology has gained more and more attentions. Wireless sensor network is one of best solutions since nodes can be easily distributed around monitored environment and relay the required sensors information. Most methods require a pre-built infrastructure with anchor nodes, whose positions are known, to locate the blind nodes (unanchored nodes). These kinds of methods would take user much time to construct the system. For example, if user wants to move the locating system from one place to another, user should re-build all the anchor nodes due to the different environment. The most ideal method is to let user randomly distribute all the nodes and they will be located automatically. In this thesis, a relative-localization identification of random deployed non-anchored nodes will be presented. Based on relative RSSI information, the system can identify which sensor nodes are placed in locations that are planned on the map. The method can let user put any nodes anywhere (random distributed), and the nodes will locate themselves without knowing the coordinate (absolute or relative) beforehand. The main idea of this paper is: “Further nodes would get weaker signal strength, and vice versa.” Because the relationship between RSSI value and distance is not always fixed, the RSSI can not be transformed to distance directly. Nevertheless, we still can use the RSSI value to know which node is closer and which is further by the idea mentioned above. The distance relationship can draw the map which includes the relative locations of all the nodes. The algorithm and experimental verification of this method will all be detailed in this paper.
39
Αρβανιτόπουλος, Αναστάσιος. "Χρήση WSN για ιχνηλάτηση της τροχιάς ενός κινητού με εφαρμογή του walking GPS". Thesis, 2011. http://nemertes.lis.upatras.gr/jspui/handle/10889/4706.
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Τα τελευταια χρόνια ειμαστε μαρτυρες ενός εντυπωσιακού παραδόξου στο χώρο της τεχνολογίας. Ενώ όλη η ανθρωπότητα αναζητά το κάτι παραπάνω σε υπολογιστική ισχύ, σε χώρο αποθήκευσης και σε ταχύτητα, μικρές αυτόνομες συσκευές έρχονται να κατακτήσουν όλο και περισσότερους τομείς της καθημερινότητάς μας. Μονάδες με την ικανότητα της επεξεργασίας και της αποθήκευσης δεδομένων, της αίσθησης του περιβάλλοντος αλλά και της επικοινωνίας μεταξύ τους, ενσωματώνονται σχεδόν σε όλους τους τομείς δραστηριοποίησης του ανθρώπου. Ο τρόπος αυτό-οργάνωσης αυτών των κόμβων - μονάδων στα πλαίσια μεγάλων ασύρματων δικτύων αισθητήρων, και η συλλογή δεδομένων από μια ευρεία περιοχή, τους δίνει τη δυνατότητα λήψης αποφάσεων, πολλές φορές κρίσιμων, ανάλογα με τις επικρατούμενες συνθήκες.
Τα παραπάνω χαρακτηριστικά των δομικών στοιχείων των ασυρμάτων δικτύων αισθητήρων, σε συνδυασμό με τις υπηρεσίες της υψηλής και καθιερωμένης τεχνολογίας του συστήματος GPS (Global Positioning System) μπορούν να δημιουργήσουν έναν εκρηκτικό συνδυασμό και ερευνητικές ιδέες για ανάπτυξη αστικών εφαρμογών αυτοματισμού, στο πλαίσιο των λεγόμενων «έξυπνων πόλεων».
Μέσα σε ένα απέραντο δίκτυο ασυρμάτων αισθητήρων, αποτελούμενο από χιλιάδες οντότητες, η ικανότητα του κάθε κόμβου να εντοπίζει την θέση του και να την μοιράζεται με τους υπόλοιπους, κερδίζει ολοένα και περισσότερο έδαφος ειδικά σε θέματα δρομολόγησης. Η χρήση της τεχνολογίας GPS από έναν κόμβο, αντικείμενο που μελετάμε στη παρούσα εργασία, μπορεί να οδηγήσει από την επιτυχή εφαρμογή του Geographical Routing σε ένα WSN, μέχρι την υλοποίηση απαιτητικών εφαρμογών για αντιγραφή κίνησης αλλά και δημιουργίας «έξυπνων αυτοκινητόδρομων» μέσα στους οποίους θα γίνεται αυτόματη πλοήγηση των κινητών υπό την επίβλεψη ενός μεγάλου WSN με κόμβους που συνεργάζονται με το σύστημα δορυφορικού εντοπισμού θέσης αλλά και μεταξύ τους.
Όπως γίνεται άμεσα αντιληπτό, η παρούσα εργασία, που πραγματεύεται την σωστή συνεργασία και επικοινωνία ενός δικτύου ασυρμάτων αισθητήρων με την τεχνολογία GPS για την ιχνηλάτηση της πορείας ενός κινητού, μπορεί να δώσει μελλοντική τροφή για ενασχόληση σε πολλαπλά ερευνητικά επίπεδα.
Η εργασία μας χωρίστηκε σε τρείς θεματικές ενότητες. Η πρώτη αφορά τον τομέα του WSN και του προγραμματισμού των κόμβων, για επικοινωνία με τους δορυφόρους, με τον υπολογιστή αλλά και μεταξύ τους, με τις απαραίτητες λειτουργικές εφαρμογές που κληθήκαμε να υλοποιήσουμε. Η δεύτερη αναφέρεται στην εργασία μας από την πλευρά του υπολογιστή, που λειτουργεί σαν συλλέκτης των δεδομένων του δικτύου, και τη σύνδεση του συστήματός μας με την πρότυπη εφαρμογή Google EarthTM για απεικόνιση σε πραγματικό χρόνο της τροχιάς που ακολουθεί ένα κινητό. Η τρίτη ενότητα περιλαμβάνει εκτέλεση πειραμάτων χρήσης του συστήματος που σχεδιάσαμε και παράθεση οπτικοποιημένων αποτελεσμάτων, για την εύκολη εξαγωγή χρήσιμων συμπερασμάτων όσον αφορά στη λειτουργικότητά του.The last few years we witness a striking paradox in the field of technology. While all humanity is seeking for more computing power, more storage capabilities and more proccessing speed, small autonomous devices have appeared to occupy more and more areas of our lives in the daily routine. Units with the capabilities of data proccessing, data storage, enviromental sensing and communication with each other, are incorporated in almost all areas of human activity. The way in which these nodes are self-organized into large Wireless Sensor Networks and their ability to collect data from a wide area, enables them in taking decisions, critical ones sometimes, according to the prevailing conditions. The above characteristics of the components of wireless sensor networks, combined with the services of the established and standard technology of the GPS (Global Positioning System) can create ideas for research and development of urban applications of automation in the so-called “smart cities”. In a vast network of wireless sensors, consisting of thousands of entities, the ability of each node to detect its position and share it with others, is gaining more and more ground especially in routing topics. The use of GPS technology from a node, which is one of the subjects we study in this thesis, could lead from the successful implementation of the Geographical Routing, to the implementation of more demanding applications for motion replication but also to creating “smart highways” through which mobiles will execute an automatic navigation, supervised by a large WSN consisting of nodes cooperating with the satellite positioning system and with each other. As is readily apparent, the present thesis which is dealing with the good cooperation and communication of a wireless sensor network with the GPS technology in order to trace the path of a mobile, can provide room for future involvement in multiple levels of research. Our work was divided into three thematic sections. The first concerns the field of WSN and node programming so that they can be able to communicate with satellites, with the computer and with each other, by installing them with the necessary functional applications that we had to implement. The second section refers to our work on the computer side, which acts as a network data collector, and the link of our system with the standard Google EarthTM application to display the path of a mobile in real – time. The third section includes conducting experiments using the system we designed. The results are visualised and listed for an easy extraction of usefull conclusions regarding the functionality of our system.
40
Chen, I.-Ray y 陳奕瑞. "Dynamic Installation of the Reference Nodes for Indoor Localization Tracking". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/75159429931882373071.
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碩士淡江大學
資訊工程學系碩士班
99
In recent years, a number of wireless sensor network localization applications have been developed, such as personnel and object monitoring, and so on. Of all, IEEE 802.15.4/ZigBee wireless sensor network localization system has the features of low-power and low-cost, so it has become one of the widely used wireless sensor network localization systems. However, the chief drawback is that its Reference Node needs setting up in advance and if there are no appropriate measurement tools, it would be quite inconvenient and time-consuming to set it up manually. In this thesis, we propose a dynamic indoor localization system in which Reference Node can automatically calculates and sets up its own coordinates and we make Reference Node regulate its coordinates within a particular period of time. And finally we use the Dead-Reckoning Algorithm to correct the path of detected objects.
41
Huang, Yu-hsin y 黃瑀昕. "Localization and Target Tracking with Improved GDOP using Mobile Sensor Nodes". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/86277870222127100142.
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碩士國立中山大學
電機工程學系研究所
98
In wireless positioning system, in addition to channel error, the geometric re- lationship between sensor nodes and the target may also affect the positioning accuracy. The effect is called geometric dilution of precision (GDOP). GDOP is determined as ratio factor between location error and measurement error. A higher GDOP value indicates a larger location error in location estimation. Accordingly, the location performance will be poor. The GDOP can therefore be used as an in- dex of the positioning performance. In this thesis, approaches of tracking a moving target with extended Kalman filter (EKF) in a time-difference-of-arrival (TDOA) wireless positioning system are discussed. While the target changes its position with time, the geometric layout between sensor nodes and the target will become differ- ent. To maintain the good layout, the positioning system with mobile sensor nodes is considered. Therefore, the geometric layout can be possibly improved and GDOP effect can be reduced by the mobility of mobile sensor nodes. In order to find the positions that mobile sensor nodes should move to, a time-varying function based on the GDOP distribution is defined for finding the best solutions. Since the simu- lated annealing is capable of escaping local minima and finding the global minimum in an objective function, the simulated annealing algorithm is used in finding the best solutions in the defined function. Thus the best solutions can be determined as the destinations of mobile sensor nodes. When relocating mobile sensor nodes from their current positions to the destinations, they may pass through or stay in high GDOP regions before arriving at the destinations. To avoid the problem, we establish an objective function for path planning of mobile sensor nodes in order to minimize the overall positioning accuracy. Simulation results show that the mobile sensor nodes will accordingly change their positions while the target is moving. All the sensor nodes will maintain a surrounding region to localize the target and the GDOP effect can be effectively reduced.
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Carvalho, Guilherme. "Unmanned Air Vehicle Based Localization and Range Estimation of Wi-Fi Nodes". Dissertação, 2014. http://hdl.handle.net/10216/73751.
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Carvalho, Guilherme Gonçalves Coelho de Freitas. "Unmanned Air Vehicle Based Localization and Range Estimation of Wi-Fi Nodes". Dissertação, 2014. https://repositorio-aberto.up.pt/handle/10216/71565.
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Carvalho, Guilherme Gonçalves Coelho de Freitas. "Unmanned Air Vehicle Based Localization and Range Estimation of Wi-Fi Nodes". Master's thesis, 2014. https://repositorio-aberto.up.pt/handle/10216/71565.
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Ou, Chia-Ho y 歐家和. "Mobile Assisting Nodes for Localization and Transmission in Wireless Sensor Ad Hoc Networks". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/00069536928348229686.
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博士國立成功大學
電機工程學系碩博士班
93
Many research challenges in mobile ad hoc and wireless sensor networks, such as capacity, transmission, coverage, localization, security etc., need mobility support to upgrade their performance. This thesis develops mobile assisting nodes to support localization process in sensor networks and to improve data transmission in disconnected ad hoc networks. Localization is one of the substantial issues in wireless sensor networks. Several approaches, including range-based and range-free, have been proposed to calculate positions for randomly deployed sensor nodes. With specific hardware, the range-based schemes typically achieve high accuracy based on either node-to-node distances or angles. On the other hand, the range-free mechanisms support coarse positioning accuracy with the less expense. This thesis describes range-free localization schemes using mobile assisting nodes for two & three-dimensional wireless sensor networks. Each assisting node equipped with the GPS moves in the sensing field and broadcasts its current position periodically. The sensor nodes obtaining the information are able to compute their locations. With the scheme, no extra hardware or data communication is needed for the sensor nodes. Moreover, obstacles in the sensing fields can be tolerated. The localization mechanism has been implemented in the network simulator ns-2. The simulation results demonstrate that the scheme outperformed other range-free mechanisms. An ad hoc network topology could be partitioned due to node mobility or geographic limitations. A serious problem, disconnection in the ad hoc network, thus affects both data communication and information availability. However, most previous routing protocols assumed that the ad hoc network was never partitioned. This thesis also utilizes the assisting nodes to recover the disconnected mobile ad hoc networks with two movement algorithms. With Boundary Movement Mechanism (BMM), the assisting nodes move to boundaries of network partitions for linking disconnected networks. With Zone Movement Mechanism (ZMM), the assisting nodes travel along the data delivery zones to help relaying packets. Both algorithms are distributed and self-organized. In addition, they can be easily integrated with routing protocols. Both algorithms have been implemented in the network simulator ns-2. Three other strategies, including random stationary, random movement, and circular movement, were also evaluated for performance comparison. The simulation results show that both BMM and ZMM can efficiently improve data delivery and recover the network partitions.
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Dixit, Vijay Vasant. "A particle filter based framework for indoor wireless localization using custom IEEE 802.15.4 nodes". 2008. http://hdl.handle.net/10106/1818.
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Behzad, Ali Reza. "Localization of latent adenovirus infection in human lungs and lymph nodes by in situ PCR". Thesis, 1998. http://hdl.handle.net/2429/7995.
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Cigarette smoking is a major risk factor for chronic obstructive pulmonary disease (COPD), but
only 15 to 20% of smokers develop airways obstruction. Respiratory infection caused by group
C adenoviruses is a possible independent risk factor for COPD. Our working hypothesis is that
adenoviral E l A D N A persists in airway epithelial cells following respiratory infections and is
capable of amplifying cigarette smoked-induced airway inflammation. To develop a protocol
that has the potential to detect low copy numbers of adenovirus E l A D N A in histological
preparations of human lungs and lymph nodes, we first optimized in situ amplification o f E l A
DNA and subsequent detection of the D N A by in situ hybridization (indirect in situ PCR) on
cytospin and paraffin embedded preparations of Graham 293 cells which are known to have 4 to
5 copies of adenoviral E l A gene per cell. Using optimal conditions established for this indirect
in situ PCR on paraffin embedded sections of Graham 293 cells, this procedure was performed
on paraffin embedded sections of guinea pig lungs 20 days after the resolution of an acute
infection with adenovirus 5 when no replicating virus could be recovered from these lungs
(Vitalis, et al., 1996) and lungs and lymph nodes from COPD and non-COPD patients. For
successful indirect in situ amplification of E l A D N A in Graham 293 cells, a "hot start"
technique with 2 m M MgCl₂, 1.5 µM E l A primers and 30 cycles of amplification was used.
Application of indirect in situ PCR on cytospin preparations of Graham 293 cells after
pretreatment with 50 µg/ ml proteinase K for 5 minutes at 37°C resulted in nuclear staining in
approximately 60% of the cells, while paraffin embedded 293 cells that had been digested with 1
mg/ ml pepsin in 0.2 N HC1 at room temperature exhibited nuclear staining in approximately
40% of the cells. Staining was not seen in uninfected A549 cells nor in Graham 293 cells
hybridized with an irrelevant probe or when Taq polymerase was omitted during amplification.
Indirect in situ P CR on paraffin embedded sections of latently infected guinea pig lungs revealed nuclear staining in bronchiolar and type II alveolar epithelial cells. Nuclear staining was also
observed in alveolar epithelial cells when indirect in situ PCR was performed on paraffin
embedded sections of lungs from COPD patients. As a comparison, direct in situ PCR, where
labeled nucleotide is incorporated during amplification, was performed on cytospin and paraffin
embedded sections of Graham 293 cells using optimal conditions established for indirect in situ
PCR. Our preliminary results from direct in situ PCR revealed significant problems of
nonspecific signals. Our findings indicate that indirect in situ P C R allows the detection of 4 to 5
copies of adenovirus E l A D N A in Graham 293 cells. Localization of adenovirus E l A D N A in
alveolar epithelial cells could have important implications regarding the regulation of
proinflammatory agents that mediate neutrophil migration into the alveolar walls.
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Yeh, Sheng-Wei y 葉昇韋. "Simulation and Analysis of Collaborative Localization mechanism based on Distance Estimation between Nodes in Wireless Ad Hoc Networks". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/49976747161705826668.
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碩士國立臺北教育大學
資訊科學系碩士班
101
In recent years, the mobile device and wireless ad hoc network technique have been well developed. In addition, the applications of location technique also become mature. Therefore, under the wireless ad hoc network with enormous nodes, utilizing the received signal strength (RSS) between some fixed reference nodes and the collaborative localization mechanism to find the location of blind nodes is a popular issue in research. Regarding the related works, the algorithm which depends on the received signal strength indicator (RSSI) is the most intuitive way and doesn’t need to cooperate with other hardware devices. However, the accuracy of RSSI would be greatly affected by the outside interference. Besides, owing to the enormous number of nodes in massive ad hoc network, it is complicated to obtain the related parameters and datum which are required for simulation. In this thesis, the distance between any two nodes is estimated by utilizing RSSI and related distance model. And a collaborative localization mechanism is proposed. In this mechanism, a blind node’s location can be calculated by estimating the distance between more than three reference nodes and then using multilateration technique. Under the scenario that the distance between any two nodes is less than 150m, the simulation results demonstrate that the deviation distance between the practical location and the location obtained from proposed method can improve to be less than 6.09 meters.
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Adewumi, Omotayo Ganiyu. "Perturbation analysis and performance evaluation of a distance based localisation for wireless sensor networks". 2013. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001366.
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M. Tech. Electrical Engineering.Discusses node location as a major problem when considering several areas of application based on wireless sensor networks. Many localisation algorithms have been proposed in the literature to solve the problem of locating sensor nodes in WSN. However, most of these algorithms have poor localisation accuracy and high computational cost. Due to these limitations, this research study considers the modelling of an efficient and robust localisation scheme to determine the location of individual sensor nodes in WSN. To successfully solve this task, this research study focuses on the aspect of improving the position accuracy of wireless sensor nodes in WSN. The study considers a distance based cooperative localisation algorithm called Curvilinear Component Analysis Mapping (CCA-MAP) to accurately localise the sensor nodes in WSN. CCA-MAP is used because it delivers improved position accuracy and computational efficiency.
50
Caetano, José Miguel Marques. "Development of an Odor Compass: 2D Thermal Anemometer with Olfactory Information". Master's thesis, 2017. http://hdl.handle.net/10316/83123.
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Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e TecnologiaMuitos animais usam o olfato como um sentido de orientação combinando a informação sobre a concentração de um odor específico, presente no ar, e a velocidade do vento. Este tipo de deteção está ligado aos conceitos de deteção baseados em quimiotaxia e anemotaxia, uma vez que se consideram as propriedades químicas e eólicas aquando da localização da origem de um odor. No entanto, o olfato é muitas vezes desprezado, pelos seres humanos, como um sentido de orientação, não sendo, portanto, objeto de profunda investigação e/ou desenvolvimento. Assim, esta tese pretende dar uma contribuição nesta área através do desenvolvimento de um compasso de odores baseado em métodos térmicos, para medir as propriedades de um fluido, e um sensor de gás eletroquímico, de forma a medir a concentração do odor. Os compassos de odor são adequados para o uso em robôs móveis, possibilitando o rastreamento ativo de um odor, e em redes de sensores ambientais, permitindo um rastreamento estático de odor. Estes podem, portanto, ser usados em aplicações como o controlo de ambientes de vida e de trabalho num edifício, inspeção de ambientes perigosos utilizando robôs móveis, deteção de drogas e explosivos, e deteção precoce de incêndios florestais. Para desenvolver tal dispositivo, foram colocados vários termístores, também designados de elementos aquecidos, em torno de uma estrutura triangular, permitindo que a relação entre as suas respostas possa ser utilizada para determinar a direção da origem de um odor enquanto se usa um sensor de gás de óxidos metálicos para medir a concentração do mesmo.Testes em laboratório realizados com etanol, de forma a produzir a quantidade desejada de odor, e um processo de calibração completamente automatizado, mostraram que o sensor desenvolvido consegue indicar a direção da origem de um odor com precisão, medindo a velocidade do fluxo de ar com um erro absoluto médio de 0,0245 m/s e a direção do fluxo de ar com um erro absoluto médio de 3%.
Many animals use olfaction as a sense of orientation by combining the information regarding the concentration of a specific odor present in the air and the velocity of the wind. This type of detection is linked to the concepts of chemotaxis and anemotaxis based detection, since both chemical and wind properties are considered when locating the source of an odor. However, olfaction is often disregarded by humans as a sense of orientation, thus not being subject of deep research and/or development. Therefore, this thesis intends to give a contribution in this area through the development of an odor compass based on thermal methods for measuring the flow properties of a fluid and an electrochemical gas sensor for measuring its odor concentration. Odor compasses are suitable for usage in both mobile robots, in order to perform an active odor tracing, and environmental sensor networks, allowing for a static odor tracing. They can, therefore, be used in applications like control of living and working environments in a building, inspection of dangerous environments with mobile robots, drugs and explosives detection and earlier detection of active wildfires. To develop such a device, multiple thermistors, also referred to as heated elements, were placed around a triangular structure, so that the relation between their responses can be used to determine the direction of the odor source, while a metal oxide gas sensor was used to measure the odor concentration.Indoor experiments realized with ethanol, in order to produce the desired amount of odor, and a fully automated calibration process showed that the developed sensor could indicate the direction of the odor source with precision, measuring the airflow velocity with a mean absolute error of 0.0245 m/s and the airflow direction with a 3% mean absolute error.