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Fraher, Patrick M. A. "Environmental sensor validation." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308651.
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Hall, Geoffrey G. "Remote environmental sensor array system." Thesis, Kingston, Ont. : [s.n.], 2007. http://hdl.handle.net/1974/943.
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Hernandez, Unpingco Jose. "Environmental source tracking using one sensor /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9821366.
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Myint, Cho Zin. "Reconfigurable Wireless Sensor Network Design for Environmental Monitoring in IoT Environment." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/76187.
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This study presents a reconfigurable wireless sensor network (WSN) based water quality monitoring (WQM) system in an IoT environment to measure five parameters of water such as water temperature, water level, water pH, turbidity of water and CO2 on the surface of water using sensors, Field Programmable Gate Array (FPGA), Zigbee wireless communication protocol and personal computer (PC), a VHDL language and C++ program.
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ILIE, Ana Maria Carmen. "Smart Sensor Technology for Environmental Monitoring Applications." Doctoral thesis, Università degli studi di Ferrara, 2018. http://hdl.handle.net/11392/2487882.
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Research Project focused on developing innovative devices using the low-cost sensors to obtain the concentrations of greenhouse gases (GHGs) such as carbon dioxide (CO2) and methane (CH4) as well as obtain a good water quality as a 2nd treatment in the Wastewater Treatment Plant. In addition to sensor calibration, the multi-parameter monitor prototype were tested in several contexts: a) Laboratory scale with natural soil columns, to figure out the sensor response under controlled conditions, calibration and validation; b) Field scale in many geological contexts, for Air-Soil quality (methane and carbon dioxide measurements): Natural Gas Storage Site in Minerbio, Italy; Drilling and Hydraulic Fracturing activities in Greeley, CO, USA; for Water Quality: Wastewater Treatment Plant in Algarve, Portugal. The monitoring system provided a huge set of data for which can be used statistical analysis, management and processing (Big DATA). The source identification of greenhouse gas emissions is identified in several IPCC reports that climate change is the major emergency for the socio / economic / environmental equilibrium of Earth planet. No outliers were identified as methane gas concentrations at Minerbio gas storage site, Italy and at Hydraulic activities in Greeley, Colorado. The soil column experiments for infiltration basins in the Wastewater treatment plant in Algarve, Portugal, gave us good results, the water quality was improved after the 2nd treatment. The low-cost sensors (gas – water) gave as a good calibration and validation with r2 coefficient of correlation of 0.70 – 0.96.<br>Il progetto di ricerca si è concentrato sullo sviluppo di dispositivi innovativi utilizzando i sensori a basso costo per ottenere le concentrazioni di gas (GHG) quali anidride carbonica (CO2) e metano (CH4) e ottenere una buona qualità dell'acqua come secondo trattamento nelle acque reflue nell’impianto di trattamento. Oltre alla calibrazione del sensore, il prototipo di monitoraggio multiparametro è stato testato in diversi contesti: a) Nel laboratorio con colonne di terreno naturali, suoli, per determinare la risposta del sensore in condizioni controllate, calibrazione e validazione; b) Scala di campo in molti contesti geologici, per la qualità Aria-suolo (misure di metano e anidride carbonica, radon) nel sito di stoccaggio di gas naturale a Minerbio, Italia; Attività di perforazione e fratturazione idraulica in Greeley, Colorado, USA; per la qualità dell'acqua: impianto di trattamento delle acque reflue in Algarve, Portogallo. Il sistema di monitoraggio ha fornito un enorme set di dati per i quali è stato possibile utilizzare analisi statistiche, gestione ed elaborazione (Big DATA). L'identificazione della fonte delle emissioni di gas è stata identificata in diversi rapporti dell'IPCC secondo cui i cambiamenti climatici rappresentano l'emergenza principale per l'equilibrio socio / economico / ambientale del pianeta Terra. Non sono stati identificati valori anomali come concentrazioni di gas metano nel sito di stoccaggio di Minerbio (Italia) e nelle attività di perforazione in Greeley, Colorado, USA. Gli esperimenti con la colonna di terreno per i bacini di infiltrazione nell'impianto di trattamento delle acque reflue in Algarve, in Portogallo, ci hanno dato buoni risultati, la qualità dell'acqua è stata migliorata dopo il 2 ° trattamento. I sensori a basso costo (gas - acqua) per la qualita’ dell’aria e del suolo, hanno fornito una buona calibrazione e validazione con coefficiente di correlazione r2 di 0,70 - 0,96.
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Mokhtary, Mandana. "Sensor Observation Service for Environmental Monitoring Data." Thesis, KTH, Geodesi och geoinformatik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-95830.
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The Swedish Environmental Protection Agency (Naturvårdsverket) is the public agency in Sweden with responsibility to overview the conditions of the environment and the policies related to the environmental monitoring data. Nowadays, observation data are stored in several different data models in this organization, leading to difficulties in finding, understanding and consequently using data in terms of analysis and management of environmental issues. One common model that uniformly structures observation data could largely make it easier for decision makers to find the required information. The aim of this study is to build an interoperable data model for environmental monitoring observation in Naturvårdsverket based on OGC-SWE standard formats. The proposed solution relies on Sensor Web architecture, which is the set of data model definitions andweb service specifications. Also, this methodology is based on open source components; therefore it is cost-effective for the users. The Service Oriented Architecture (SOA) is used to create a uniform model by using communication protocols such as Extensible Markup Language (XML) and Simple Object Access Protocol (SOAP). The primary findings of the thesis is that when the observation is encoded into the standard format from the beginning, then it is easier to parse these documents and find the required information for the end users without knowing how these information are gathered and stored. The client scan send a request to the Sensor Observation Service (SOS) and receive the observation that is structured based on Observation and Measurements (O&M).
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Conde, Erick F. "Environmental Sensor Anomaly Detection Using Learning Machines." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1050.
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The problem of quality assurance/quality control (QA/QC) for real-time measurements of environmental and water quality variables has been a field explored by many in recent years. The use of in situ sensors has become a common practice for acquiring real-time measurements that provide the basis for important natural resources management decisions. However, these sensors are susceptible to failure due to such things as human factors, lack of necessary maintenance, flaws on the transmission line or any part of the sensor, and unexpected changes in the sensors' surrounding conditions. Two types of machine learning techniques were used in this study to assess the detection of anomalous data points on turbidity readings from the Paradise site on the Little Bear River, in northern Utah: Artificial Neural Networks (ANNs) and Relevance Vector Machines (RVMs). ANN and RVM techniques were used to develop regression models capable of predicting upcoming Paradise site turbidity measurements and estimating confidence intervals associated with those predictions, to be later used to determine if a real measurement is an anomaly. Three cases were identified as important to evaluate as possible inputs for the regression models created: (1) only the reported values from the sensor from previous time steps, (2) reported values from the sensor from previous time steps and values of other water types of sensors from the same site as the target sensor, and (3) adding as inputs the previous readings from sensors from upstream sites. The decision of which of the models performed the best was made based on each model's ability to detect anomalous data points that were identified in a QA/QC analysis that was manually performed by a human technician. False positive and false negative rates for a range of confidence intervals were used as the measure of performance of the models. The RVM models were able to detect more anomalous points within narrower confidence intervals than the ANN models. At the same time, it was shown that incorporating as inputs measurements from other sensors at the same site as well as measurements from upstream sites can improve the performance of the models.
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Tosatto, Silvia. "A teledetection system based on surface plasmon resonance sensors for environmental pollutants." Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3422980.
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Surface Plasmon Resonance (SPR) sensors are thin-film refractometers that measure changes in the refractive index that take place at the surface of a metal film supporting a surface plasmon (Homola, 2008).
The research activity consisted on a study and realization of innovative Surface Plasmon Resonance based sensors and of their applications, in particular for the environment monitoring.
In order to investigate the possibility of creating innovative SPR sensors, computer simulations of optical structures supporting surface plasmon polaritons and comprising peculiar materials were implemented. In particular SPR sensors based on metals showing Inverted Surface Plasmon Resonance and a single layer of Graphene (SGL) were simulated. An article has been submitted on this study.
Surface Plasmon Resonance sensor prototypes were also realized in laboratory. By means of a first SPR sensor with dynamic setup, measurements with Helium and Pentane gases were made, then an SPR sensor with a static setup was assembled, refined and as a following improvement in the optical components an adaptive mirror also introduced, which was able to counteract, if present, a lens defocus, spherical aberration, coma and astigmatism .
Moreover the elements of a feasible wireless sensor network based on Surface Plasmon Resonance sensors, the possible data that can be inferred from a SPR sensor and a possible data handling strategy were determined along with an evaluation of the sensor module energy requirements.
Then two small wireless sensor network test setups were implemented in laboratory, each one composed of two SPR sensors controlled by a computer or a microcontroller, ZigBee antennas and a main computer for the data reception and diffusion into Internet.
The feasibility of a Wireless Sensor Network based on SPR sensors, conceived for environmental pollutants detection and with broadband internet connection, has been demonstrated and two different laboratory setups for a test Wireless Sensor Network based on Surface Plasmon Resonance Sensors were realized.<br>I sensori basati sulla plasmonica di superficie (SPR) sono rifrattometri, basati sulla fisica dei film sottili, che misurano le variazioni di indice di rifrazione che avvengono sulla superficie di uno strato metallico supportante un plasmone di superficie (Homola , 2008).
L’ attività di ricerca si è sviluppata come uno studio ed implementazione di sensori SPR innovativi e delle loro possibili applicazioni, in particolare per la rilevazione di sostanze inquinanti.
Sono stati simulati in ambiente Matlab sensori SPR innovativi, comprendenti materiali peculiari. Tali sensori comprendono in particolare metalli mostranti una Risonanza Plasmonica Invertita (ISPR), oltre che un singolo strato di Graphene (SGL). Un articolo è stato sottomesso su tali studi.
Sono stati inoltre implementati in laboratorio vari prototipi di sensori basati sulla plasmonica di superficie. Innanzi tutto sono state effettuate delle misure di riflettività con i gas elio e pentano mediante un sensore basato sulla plasmonica di superficie e con un setup dinamico, quindi è stato creato un nuovo sensore utilizzante un un sistema ottico di tipo statico ed un prisma cilindrico ad alto indice di rifrazione, migliorando il più possibile la qualità del fascio ottico e filtrandolo opportunamente. Altresì è stato innovativamente utilizzato nel setup ottico uno specchio deformabile, in grado di correggere le aberrazioni ottiche presenti nello stesso.
Oltre a ciò sono stati individuati i possibili elementi di una rete wireless di sensori SPR progettata per il monitoraggio ambientale, i dati ottenibili da un sensore SPR, una strategia per la diffusione dei dati ed una stima dei consumi energetici.
Infine sono stati implementati in laboratorio due diversi setup di prova per una piccola rete wireless di sensori, formata da due sensori SPR controllati da un computer o da un microcontrollore, antenne ZigBee e da un computer principale per la ricezione, analisi e diffusione in Internet dei dati.
L’ attività di ricerca presentata in questa tesi ha quindi dimostrato la possibilità della creazione di una rete wireless di sensori basati sulla Plasmonica di Superficie e con accesso Internet a banda larga, finalizzata alla rilevazione di sostanze inquinanti in ambiente acquoso, e due piccole versioni di prova della stessa sono state implementate in laboratorio.
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Marinakis, Dimitrios. "Inferring environmental representations through limited sensory data with applications to sensor network self-calibration." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66780.
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This thesis addresses the problem of using distributed sensing for automatically inferring a representation of the environment, i.e. a map, that can be useful for the self-calibration of intelligence systems, such as sensor networks. The information recovered by such a process allows typical applications such as data collection and navigation to proceed without labour intensive input from a human technician. Simplifying the deployment of large scale sensor networks and other intelligent systems will effectively reduce their cost and improve their widespread availability and hence aid their practical application to tasks such as the monitoring of carbon emissions and greenhouse gases. In our research we focus on algorithms and techniques for recovering two types of information from the immediate environment: topology information that indicates physical connectivity between regions of interest from the point of view of a navigating agent; and a probability distribution function (PDF) describing the position of components of the intelligent system. We consider situations where data is collected from systems that comprise of: a number of stationary network components; stationary network components augmented with a mobile robot; or a mobile robot only. Our approaches are, for the most part, based on statistical methods that employ stochastic sampling techniques to provide approximate solutions to problems for which computing the optimal or exact solution is intractable. Numerical simulations and experiments conducted on hardware suggest that this research has promising real world applications in the area of sensor network self-configuration.<br>Ce thèse s'adresse au problème de l'emploi de la détection dispersée pour déduire automatiquement une représentation de l'environnement, c'est-à-dire une carte, qui peut servir dans l'autocalibrage des systèmes intelligents tels que les réseaux des capteurs. L'information récupérée par un tel processus permet aux applications typiques telle que la collecte des données et la navigation de continuer sans une contribution de main d'œuvre de la part d'un technicien humain. Simplifier la répartition en grand des réseaux de capteurs et d'autres systèmes intelligents réduira effectivement leur coût et améliora leur disponibilité répandue, donc il facilitera leur application pratique aux tâches comme le contrôle des émissions de carbone et les gaz à effet de serre.Dans nos recherches nous nous concentrons sur les algorithmes et les techniques pour récupérer deux types d'information de l'environnement immédiat : l'information topologique qui indique la connectivité physique entre les régions d'intérêt du point de vue d'un agent navigateur; et une fonction de dispersion de probabilité (PDF) qui décrit la position des élément du système intelligent. Nous considérons les situation où les données se recueillent des systèmes composés de: plusieurs éléments fixes du réseau; des éléments fixes du réseau augmentés d'un robot mobile; un robot mobile seulement. Nos approches sont, pour la plupart, fondées sur des méthodes statistiques qui emploient des techniques stochastiques d'échantillonnage pour fournir des solutions approximatives aux problèmes dont le calcul d'une solution exacte ou optimale reste réfractaire. Les simulations numériques et les expériences exécutées au matériel suggèrent que ces recherches promettent des applications actuelles et pratiques dans le domaine d'autocalibrage des réseaux de capteurs.
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Suzuki, Takeharu, and n/a. "Integrated, Intelligent Sensor Fabrication Strategies for Environmental Monitoring." Griffith University. School of Microelectronic Engineering, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040813.131206.
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The humidity, temperature, wind speed/direction micro sensors can be manufactured individually, resulting in three individual substrates. The integration of the three sensors into a single substrate is a vital challenge to achieve an integrated intelligent sensor so called a multiple sensor. This requires the integration of process flows and is a major challenge because adequate sensor performance must be maintained. Polyimide was selected as a humidity sensing material for its compatibility with conventional integrated circuit fabrication technology, negligible temperature dependence and good resistance against contamination. Nickel was selected for the temperature and wind speed/direction sensor because of its useful temperature coefficient and the advantage of its cost. Since the known wet etchant for nickel requires hard-baked photoresist, a method which does not attack the polyimide while removing the photoresist must be developed. The method developed for etching nickel employs hard-bake-free photoresist. Other challenge was ensuring good thermal isolation for the wind speed/direction sensor fabricated on a silicon nitride layer preformed on top of a silicon wafer. Since silicon acts as a good heat sink, the silicon under the sensor was etched entirely away until the silicon nitride layer was reached. This structure achieved good thermal isolation resulting in small power consumption. This low power feature is essential for sensors deployed in fields where power access or replacement of power sources is restricted. This structure was compared with the structure created by polyimide plateau on a silicon nitride layer coated on a silicon substrate as a function of power consumption. Based on the examination of thermal isolation, the multiple sensor utilizing a MEMS technique was fabricated with a single-sided mask aligner. The characteristics of humidity sensors fabricated with polyimide were examined in detail with respect to variations of electrode structures, improvement of sensitivity, effect of process temperature, temperature and frequency dependence, and stability. The humidity sensor constructed with O2 plasma treated polyimide resulted an improvement in sensitivity and hysteresis. The investigation using XPS, FTIR and AFM concluded the chemical modification of polyimide played an important role in this improvement. The design, fabrication and results of a series of humidity sensors are quantified. There is always no unique packaging solution for sensors because of the application-specific nature of the sensors. This intelligent environmental monitoring system was designed to accommodate both an environmental sensor and its signal conditioning electronics circuitry (SICONEC) into a single package. The environmental sensors need direct exposure to the environment while SICONEC needs a sealed encapsulation to avoid environmental damage. A new style of packaging addressing these requirements was demonstrated using a hot embossing machine. The hot embossing machine was used to embed an integrated circuit (IC) in a bare die condition into a polycarbonate (PC) sheet. In this case, the IC was flipped down against the PC, which protects the front side of the IC from the environmental damages. In a test phase, a die containing operational amplifiers was embossed into the PC. A humidity sensor and surface mount resisters were placed on the same surface of the PC to test the validity of this new technique. Interconnection between the embossed die and the humidity sensor was established using bonding wires. Copper tracks were also used to ensure all electrical connections for the die, the humidity sensor and the resistors. The results clarified the method developed. Details of process methods, issues and further potential improvement are reported.
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Truax, Stuart. "A microscale chemical sensor platform for environmental monitoring." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/45780.
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The objective of this research is to apply micromachined silicon-based resonant
gravimetric sensors to the detection of gas-phase volatile organic compounds (VOCs). This
is done in two primary tasks: 1) the optimization and application of silicon disk resonators
to the detection of gas-phase VOCs, and 2) the development and application of a novel
gravimetric-capacitive multisensor platform for the detection of gas-phase VOCs.
In the rst task, the design and fabrication of a silicon-based disk resonator structure
utilizing an in-plane resonance mode is undertaken. The resonance characteristics of the
disk resonator are characterized and optimized. The optimized characteristics include the
resonator Q-factor as a function of geometric parameters, and the dynamic displacement
of the in-plane resonance mode. The Q-factors of the disk resonators range from 2600 to
4360 at atmosphere for disk silicon thicknesses from 7 µm to 18 µm, respectively.
The resonance frequency of the in-plane resonance mode ranges from 260 kHz up to 750 kHz.
The disk resonators are applied to the sensing of gas-phase VOCs using (poly)isobutylene
as a sensitive layer. Limits of detection for benzene, toluene and m-xylene vapors of 5.3
ppm, 1.2 ppm, and 0.6 ppm are respectively obtained. Finally, models for the limits of
detection and chemical sensitivity of the resonator structures are developed for the case of
the polymer layers used.
In the second task, a silicon-based resonator is combined with a capacitive structure
to produce a multisensor structure for the sensing of gas-phase VOCs. Fabrication of the
multisensor structure is undertaken, and the sensor is theoretically modeled. The baseline
capacitance of the capacitor component of the multisensor is estimated to be 170 fF. Finally,
initial VOC detection results for the capacitive aspect of the sensor are obtained.
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Suzuki, Takeharu. "Integrated, Intelligent Sensor Fabrication Strategies for Environmental Monitoring." Thesis, Griffith University, 2004. http://hdl.handle.net/10072/367295.
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The humidity, temperature, wind speed/direction micro sensors can be manufactured individually, resulting in three individual substrates. The integration of the three sensors into a single substrate is a vital challenge to achieve an integrated intelligent sensor so called a multiple sensor. This requires the integration of process flows and is a major challenge because adequate sensor performance must be maintained. Polyimide was selected as a humidity sensing material for its compatibility with conventional integrated circuit fabrication technology, negligible temperature dependence and good resistance against contamination. Nickel was selected for the temperature and wind speed/direction sensor because of its useful temperature coefficient and the advantage of its cost. Since the known wet etchant for nickel requires hard-baked photoresist, a method which does not attack the polyimide while removing the photoresist must be developed. The method developed for etching nickel employs hard-bake-free photoresist. Other challenge was ensuring good thermal isolation for the wind speed/direction sensor fabricated on a silicon nitride layer preformed on top of a silicon wafer. Since silicon acts as a good heat sink, the silicon under the sensor was etched entirely away until the silicon nitride layer was reached. This structure achieved good thermal isolation resulting in small power consumption. This low power feature is essential for sensors deployed in fields where power access or replacement of power sources is restricted. This structure was compared with the structure created by polyimide plateau on a silicon nitride layer coated on a silicon substrate as a function of power consumption. Based on the examination of thermal isolation, the multiple sensor utilizing a MEMS technique was fabricated with a single-sided mask aligner. The characteristics of humidity sensors fabricated with polyimide were examined in detail with respect to variations of electrode structures, improvement of sensitivity, effect of process temperature, temperature and frequency dependence, and stability. The humidity sensor constructed with O2 plasma treated polyimide resulted an improvement in sensitivity and hysteresis. The investigation using XPS, FTIR and AFMconcluded the chemical modification of polyimide played an important role in this improvement. The design, fabrication and results of a series of humidity sensors are quantified. There is always no unique packaging solution for sensors because of the application-specific nature of the sensors. This intelligent environmental monitoring system was designed to accommodate both an environmental sensor and its signal conditioning electronics circuitry (SICONEC) into a single package. The environmental sensors need direct exposure to the environment while SICONEC needs a sealed encapsulation to avoid environmental damage. A new style of packaging addressing these requirements was demonstrated using a hot embossing machine. The hot embossing machine was used to embed an integrated circuit (IC) in a bare die condition into a polycarbonate (PC) sheet. In this case, the IC was flipped down against the PC, which protects the front side of the IC from the environmental damages. In a test phase, a die containing operational amplifiers was embossed into the PC. A humidity sensor and surface mount resisters were placed on the same surface of the PC to test the validity of this new technique. Interconnection between the embossed die and the humidity sensor was established using bonding wires. Copper tracks were also used to ensure all electrical connections for the die, the humidity sensor and the resistors. The results clarified the method developed. Details of process methods, issues and further potential improvement are reported.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Microelectronic Engineering<br>Full Text
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Kawaguchi, Nobuo, and Yuya Negishi. "Instant Learning Sound Sensor: Flexible Environmental Sound Recognition System." IEEE, 2007. http://hdl.handle.net/2237/15456.
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Tashtoush, Nehad M. "SAW humidity sensor and an environmental electronic nose system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25915.pdf.
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Ramasubramanian, Vasant. "Quadrasense : immersive UAV-based cross-reality environmental sensor networks." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101827.
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Thesis: S.M., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2015.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 74-75).<br>Quadrasense explores futuristic applications in environmental sensing by integrating ideas of cross-reality with semi-autonomous sensor-aware vehicles. The cross-reality principals of telepresence, augmented reality, and virtual reality are enabled through an Unnamed-Aerial-Vehicle, a specialized imaging system, a Head-Mounted-Display, a video game engine and a commodity computer. Users may move between any of the three modes of interaction, in real-time, through a singular visual interface. Utilizing an environment built with video game technology, a system was developed that can track and move a UAV in the physical world, towards goals of sensing, exploration and visualization. This application expands on the use of video games engines for simulation by directly joining the virtual and real worlds.<br>by Vasant Ramasubramanian.<br>S.M.
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Han, Wei. "Three-tier wireless sensor network infrastructure for environmental monitoring." Diss., Kansas State University, 2011. http://hdl.handle.net/2097/9183.
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Doctor of Philosophy<br>Department of Biological & Agricultural Engineering<br>Naiqian Zhang<br>A two-tier wireless data communication system was developed to remotely monitor sediment concentration in streams in real time. The system used wireless motes and other devices to form a wireless sensor network to acquire data from multiple sensors. The system also used a Stargate, a single-board computer, as a gateway to manage and control data flow and wireless data transfer. The sensor signals were transmitted from an AirCard on the Stargate to an Internet server through the General Packet Radio Service (GPRS) provided by a commercial GSM cellular carrier. Various types of antennas were used to boost the signal level in a radio-hostile environment. Both short- and long-distance wireless data communications were achieved. Power supplies for the motes, Stargate, and AirCard were improved for reliable and robust field applications. The application software was developed using Java, C, nesC, LabView, and SQL to ensure seamless data transfer and enable both on-site and remote monitoring. Remote field tests were carried out at different locations with different GPRS signal strengths and a variety of landscapes.
A three-tier wireless sensor network was then developed and deployed at three military installations around the country – Fort Riley in Kansas, Fort Benning in Georgia, and Aberdeen Proving Ground in Maryland - to remotely monitor sediment concentration and movement in real time. Sensor nodes, gateway stations, repeater stations, and central stations were strategically deployed to insure reliable signal transmissions. Radio signal strength was tested to analyze effects of distance, vegetation, and topographical barriers. Omni- and Yagi-directional antennas with different gains were tested to achieve robust, long-range communication in a wireless-hostile environment. Sampling times of sensor nodes within a local sensor network were synchronized at the gateway station. Error detection algorithms were developed to detect errors caused by interference and other impairments of the transmission path. GSM and CDMA cellular modems were used at different locations based on cellular coverage. Data were analyzed to verify the effectiveness and reliability of the three-tier WSN.
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Opoku, Asare K. (Kennedy). "Enabling environmental fingerprinting with an NFC-powered sensor board." Master's thesis, University of Oulu, 2018. http://jultika.oulu.fi/Record/nbnfioulu-201806062468.
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Abstract. In recent times, people have become concerned about their environmental conditions, amid deteriorating global statistics on bad air quality, global warming and UV light exposure. Conventional technologies for reading environmental conditions are expensive, bulky and situated, yet, people are mobile and need portable tools to be aware of their immediate environmental conditions on demand. Smartphones are now widely used, endowed with sensors and wireless communication technologies such as Bluetooth, and Near Field Communication (NFC) for external sensor connectivity, making smartphones a viable tool for fingerprinting the environment. This thesis outlines the design, evaluation and implementation of a mobile-enabled system for environmental data collection using a portable NFC powered sensor board. The name of the system developed in this thesis is the S3 system.
The S3 system is a two-tier system which consists of S3 Android application and an online dashboard with a data repository. The S3 Android application is used for collecting and visualising environmental data; temperature, humidity, UV, ambient light, with a smartphone and a credit card-size NFC powered sensor board. The sensor data is then periodically synced to the online data repository. Additional features of the S3 application include automated feedback sampling, introductory tutorial, and user preference settings. The thesis further details the design and implementation process with scenarios, use cases, paper sketches, expert review of sketches, interface mockups, evaluation of prototype with a user study, quantitative and qualitative analysis of user study data, and finally the implementation of the S3 application. The thesis also presents a test run to demonstrate the capabilities of the S3 system as a mobile-enabled solution for crowdsourced environmental fingerprint datasets.
To the end user, the work in this thesis provides the S3 application and the NFC powered sensor card as a portable tool for personalised environmental fingerprinting. On the other hand, the intervention in this thesis will have an impact on research since the crowdsourced environmental fingerprint datasets can be valuable datasets for research. As a TEKES project, the solution also provides a proof of concept for further improvement and deployment into the commercial software market.
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Bayat, Daryoush. "Development of a long range wireless sensor platform." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2011. https://ro.ecu.edu.au/theses/469.
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Wireless Sensor Networks have emerged as an exciting field in recent years. There have been numerous studies on how to improve and standardise different aspects of wireless sensor networks. This paper aims to develop a wireless sensor network suitable for environmental monitoring applications. More specifically this paper aims to address the limited communication range of the existing wireless sensor technology. In order to achieve the desired objectives, we have initially developed a hardware platform and then integrated the hardware with a long range RF radio module to achieve the goals. The system is further enhanced with mesh networking capabilities to increase the communication range and overall reliability of the network. The developed wireless sensor network is composed of sensors, microcontroller, RF radio module, antenna and expansion connectors for additional sensors and peripheral devices. The developed wireless sensor network has been rigorously tested under three different scenarios to ensure the correct operation of the mesh network, communication range and effect of environmental obstacles such as vegetation and trees. The developed wireless sensor network has been proven to be a suitable platform for environmental monitoring applications and the modular design has made it very easy to optimise it for different applications.
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Olson, Noah Gale 1969. "Mechanical and optical behavior of a novel optical fiber crack sensor and an interferometric strain sensor." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/29259.
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Thesis (Ph. D .)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2002.<br>Includes bibliographical references.<br>The proper interpretation of measurements from an optical fiber sensor requires a full understanding of its mechanical response to external action and the corresponding change in optical output. To quantify the mechanical behavior it is necessary to know the mechanical properties of the fiber coatings. A new method for measuring the coating stiffness directly on the fiber uses nano-indentation. Special sample preparation and testing procedures were developed for the measurement of very low modulus materials using the Nano Indenter II. Results are obtained for two different acrylate coated optical fibers, namely Corning SMF28 and 3M FS-SN-4228. These results are used in understanding the behavior of the novel crack sensor and of an interferometric strain sensor. A distributed crack sensor that does not require prior knowledge of crack location and employs a small number of fibers to monitor a large number of cracks is developed. The basic design of the sensor is a polymer sheet containing an inclined fiber that is coupled to a structure. The sensor principle is that cracking in the structural member leads to cracking in the polymer sheet which induces fiber bending leading to signal loss. Monitoring the backscattered signal provides crack opening size and location. A theoretical model for optical fiber loss prediction is developed based on a combination of mechanical and optical analyses.<br>(cont.) Model prediction is found to be in relatively close agreement with experimental results. Model simulation can hence be carried out to provide guidelines for designing crack sensors for various applications. The behavior of both coated and uncoated fibers for strain measurement applications is also examined. A theoretical assessment using a three-dimensional finite element model for both coated and uncoated optical fibers is presented. Results show that the coating stiffness can significantly affect the strain transfer from the member under load to the optical fiber. The three-dimensional finite element model can provide guidelines for the optimized design of strain sensors. A straightforward analytical solution shows good equivalence with the theoretical solution under certain conditions. Experiments using an interferometer were conducted to verify the results of the theoretical study and show good correspondence.<br>by Noah Gale Olson.<br>Ph.D .
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DANG, THUY PHUOC-VINH. "Water Security Remote Sensor Data Telemetry System." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1213206918.
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Benton, Erin Nicole. "Development and Testing of Gold(I) and Europium(III) Based Sensors for Environmental Applications." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505138/.
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This dissertation focuses on the development, characterization, and analysis of luminescent materials and coatings for sensing applications, including CO2, heavy metals, and silver. Chapter 2 involves the use of a gold(I) pyrazolate trimer that is able to detect silver ions with an AgNP medium. Detection of silver is vital, because there is an influx of silver into our environment caused by the increased use of AgNP. Therefore, having a sensor that is able to differentiate between and detect only Ag ions is an important first step to solving the toxicity mystery of AgNPs. Chapter 3 focuses on the development of sensor coatings containing a Eu(III) based luminescent system for sensing dissolved CO2 without the aid of an absorption-based dye. It is well-known that monitoring CO2 levels in our environment is important since even at low concentrations it can cause adverse health effects to the human body. This work demonstrates a pH-sensitive Eu complex being used directly as a CO2 sensor without the aid of any other absorption-based dye. Chapter 4 explores the idea of developing a heavy metal sensor for lead and its ability to detect lead in wide concentration range upon changing the pH of the medium and the polymer matrix. Different heavy metals have toxicity at different concentrations, therefore, being able to change the dynamic range of the sensor is advantageous. This research is the first step towards developing a luminescent Pb sensor with a tunable dynamic range.
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Narayan, Raghu B. (Raghu Bangalore) 1977. "Wireless sensor network for ground-water monitoring." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/84823.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2002.<br>Leaf 78 blank.<br>Includes bibliographical references (leaves 76-77).<br>by Raghu B. Narayan.<br>M.Eng.
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Le, Borgne Yann-Aël. "Learning in wireless sensor networks for energy-efficient environmental monitoring." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210334.
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Wireless sensor networks form an emerging class of computing devices capable of observing the world with an unprecedented resolution, and promise to provide a revolutionary instrument for environmental monitoring. Such a network is composed of a collection of battery-operated wireless sensors, or sensor nodes, each of which is equipped with sensing, processing and wireless communication capabilities. Thanks to advances in microelectronics and wireless technologies, wireless sensors are small in size, and can be deployed at low cost over different kinds of environments in order to monitor both over space and time the variations of physical quantities such as temperature, humidity, light, or sound. <p><p>In environmental monitoring studies, many applications are expected to run unattended for months or years. Sensor nodes are however constrained by limited resources, particularly in terms of energy. Since communication is one order of magnitude more energy-consuming than processing, the design of data collection schemes that limit the amount of transmitted data is therefore recognized as a central issue for wireless sensor networks.<p><p>An efficient way to address this challenge is to approximate, by means of mathematical models, the evolution of the measurements taken by sensors over space and/or time. Indeed, whenever a mathematical model may be used in place of the true measurements, significant gains in communications may be obtained by only transmitting the parameters of the model instead of the set of real measurements. Since in most cases there is little or no a priori information about the variations taken by sensor measurements, the models must be identified in an automated manner. This calls for the use of machine learning techniques, which allow to model the variations of future measurements on the basis of past measurements.<p><p>This thesis brings two main contributions to the use of learning techniques in a sensor network. First, we propose an approach which combines time series prediction and model selection for reducing the amount of communication. The rationale of this approach, called adaptive model selection, is to let the sensors determine in an automated manner a prediction model that does not only fits their measurements, but that also reduces the amount of transmitted data. <p><p>The second main contribution is the design of a distributed approach for modeling sensed data, based on the principal component analysis (PCA). The proposed method allows to transform along a routing tree the measurements taken in such a way that (i) most of the variability in the measurements is retained, and (ii) the network load sustained by sensor nodes is reduced and more evenly distributed, which in turn extends the overall network lifetime. The framework can be seen as a truly distributed approach for the principal component analysis, and finds applications not only for approximated data collection tasks, but also for event detection or recognition tasks. <p><p>/<p><p>Les réseaux de capteurs sans fil forment une nouvelle famille de systèmes informatiques permettant d'observer le monde avec une résolution sans précédent. En particulier, ces systèmes promettent de révolutionner le domaine de l'étude environnementale. Un tel réseau est composé d'un ensemble de capteurs sans fil, ou unités sensorielles, capables de collecter, traiter, et transmettre de l'information. Grâce aux avancées dans les domaines de la microélectronique et des technologies sans fil, ces systèmes sont à la fois peu volumineux et peu coûteux. Ceci permet leurs deploiements dans différents types d'environnements, afin d'observer l'évolution dans le temps et l'espace de quantités physiques telles que la température, l'humidité, la lumière ou le son.<p><p>Dans le domaine de l'étude environnementale, les systèmes de prise de mesures doivent souvent fonctionner de manière autonome pendant plusieurs mois ou plusieurs années. Les capteurs sans fil ont cependant des ressources limitées, particulièrement en terme d'énergie. Les communications radios étant d'un ordre de grandeur plus coûteuses en énergie que l'utilisation du processeur, la conception de méthodes de collecte de données limitant la transmission de données est devenue l'un des principaux défis soulevés par cette technologie. <p><p>Ce défi peut être abordé de manière efficace par l'utilisation de modèles mathématiques modélisant l'évolution spatiotemporelle des mesures prises par les capteurs. En effet, si un tel modèle peut être utilisé à la place des mesures, d'importants gains en communications peuvent être obtenus en utilisant les paramètres du modèle comme substitut des mesures. Cependant, dans la majorité des cas, peu ou aucune information sur la nature des mesures prises par les capteurs ne sont disponibles, et donc aucun modèle ne peut être a priori défini. Dans ces cas, les techniques issues du domaine de l'apprentissage machine sont particulièrement appropriées. Ces techniques ont pour but de créer ces modèles de façon autonome, en anticipant les mesures à venir sur la base des mesures passées. <p><p>Dans cette thèse, deux contributions sont principalement apportées permettant l'applica-tion de techniques d'apprentissage machine dans le domaine des réseaux de capteurs sans fil. Premièrement, nous proposons une approche qui combine la prédiction de série temporelle avec la sélection de modèles afin de réduire la communication. La logique de cette approche, appelée sélection de modèle adaptive, est de permettre aux unités sensorielles de determiner de manière autonome un modèle de prédiction qui anticipe correctement leurs mesures, tout en réduisant l'utilisation de leur radio.<p><p>Deuxièmement, nous avons conçu une méthode permettant de modéliser de façon distribuée les mesures collectées, qui se base sur l'analyse en composantes principales (ACP). La méthode permet de transformer les mesures le long d'un arbre de routage, de façon à ce que (i) la majeure partie des variations dans les mesures des capteurs soient conservées, et (ii) la charge réseau soit réduite et mieux distribuée, ce qui permet d'augmenter également la durée de vie du réseau. L'approche proposée permet de véritablement distribuer l'ACP, et peut être utilisée pour des applications impliquant la collecte de données, mais également pour la détection ou la classification d'événements. <p><br>Doctorat en Sciences<br>info:eu-repo/semantics/nonPublished
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Lu, Bowen. "Bayesian estimation of environmental fields using mobile wireless sensor networks." Thesis, University of Essex, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635987.
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Environmental fields widely exist around us in our daily life and some of them are so important that cannot be ignored. For instance, temperature distribution, environment contamination and nuclear leaking can all be categorised as envirornmental fields. Some of the fields are invisible, some are dynamic changing and some are harmful to human. Therefore, deploying a mobile wireless sensor network (WSN) will be a better solution than manually sampling and estimating an environmental field. Bayesian framework is an elegant mathematical model that interprets the recognition procedures of human being and is widely used for iterative learning processes. Based on two regression methods in this platform, a complete field estimation solution for mobile WSNs is proposed. First, two distributed platforms are provided based on support vector regression (SVR), and centroidal Voronoi tessellation (CVT) is employed to optimise the sensor deployment. Second, to overcome the defects existed in the solution of SVR-CVT, Gaussian process regression (GPR) is being investigated due to its additional estimation accuracy information. To further improve the performance of this GPR based solution. A data selection strategy for GPR and a hybrid criterion for CVT are investigated.
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Bragg, Graeme McLachlan. "Standards-based Internet of Things sub-GHz environmental sensor networks." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/415864/.
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In recent years there has been shift in the use of wireless sensor networks from standalone systems that use bespoke methods of communication and data transfer to systems that use Internet standards and can interact more directly with the Internet. This has allowed wireless sensor networks to become a key enabler of the Internet of Things; however, the same is not true for environmental sensor networks as the focus of most existing research into Internet of Things wireless sensor networks has been on 2.4 GHz designs for indoor, urban and agricultural applications. In these applications, power, Internet connectivity and physical access are less of a challenge when compared to a typical environmental sensor network. Environmental sensor networks are used for monitoring natural processes and are generally deployed in harsh, remote environments where these factors are more of a concern. Sub-GHz radios are commonly used for communication due to their increased range and desirable propagation characteristics. Unlike wireless sensor networks, environmental sensor networks have been slow to adopt Internet standards and have continued to rely on bespoke methods of communication and data transfer, keeping their usability low. This has impeded the adoption of environmental sensor networks for earth sciences research. This thesis investigates whether the Internet standards that have helped to make wireless sensor network an important part of the Internet of Things can be applied to sub-GHz environmental sensor networks. It is demonstrated that 6LoWPAN can successfully be used with an 868 MHz network in a series of real-world deployments in the Highlands of Scotland that collected usable earth science data and facilitated research in other fields. Additionally, the suitability of these standards for real-world networks is assessed in terms of energy, throughput and latency performance and compared to a theoretical 2.4 GHz network. An publicly available open source Contiki radio driver for the CC1120 was developed as part of this work. Additionally, timing parameters for using ContikiMAC with 868 MHz radios were determines and shared with researchers at other institutions, facilitating further research into sub-GHz IoT ESNs by other researchers.
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Peng, Yang. "Smart sensing design for environment monitoring sensor networks." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Summer2008/y_peng_072208.pdf.
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Davis, Steven. "Characterisation of nanocrystalline tin oxide sensor materials." Thesis, University of Kent, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244334.
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Chatdarong, Virat 1978. "Multi-sensor rainfall data assimilation using ensemble approaches." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35493.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2006.<br>Includes bibliographical references (p. 195-203).<br>Rainfall is a major process transferring water mass and energy from the atmosphere to the surface. Rainfall data is needed over large scales for improved understanding of the Earth climate system. Although there are many instruments for measuring rainfall, none of them can provide continuous global coverage at fine spatial and temporal resolutions. This thesis proposes an efficient methodology for obtaining a probabilistic characterization of rainfall over an extended time period and spatial domain. The characterization takes the form of an ensemble of rainfall replicates, each conditioned on multiple measurement sources. The conditional replicates are obtained from ensemble data assimilation algorithms (Kalman filters and smoothers) based on a recursive cluster rainfall model. Satellite measurements of cloud-top temperatures are used to identify areas where rainfall can possibly occur. A variational field alignment algorithm is used to estimate rainfall advective velocity field from successive cloud-top temperature images. A stable pseudo-inverse improves the stability of the algorithms when the ensemble size is small. The ensemble data assimilation is implemented over the United States Great Plains during the summer of 2004.<br>(cont.) It combines surface rain-gauge data with three satellite-based instruments. The ensemble output is then validated with ground-based radar precipitation product. The recursive rainfall model is simple, fast and reliable. In addition, the ensemble Kalman filter and smoother are practical for a very large-scale data assimilation problem with a limited ensemble size. Finally, this thesis describes a multi-scale recursive algorithm for estimating scaling parameters for popular multiplicative cascade rainfall models. In addition, this algorithm can be used to merge static rainfall data from multiple sources.<br>by Virat Chatdarong.<br>Ph.D.
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Hari, Piyush. "Development of software architecture for environmental monitoring using wireless sensor networks." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35083.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2006.<br>Includes bibliographical references (leaves 53-54).<br>In this thesis, I describe the development of the software architecture for temperature monitoring using Wireless Sensor Networks (WSN). The goal of the software is to provide a means to remotely monitor and analyze temperature data in a closed environment. This architecture forms a building block to achieve the larger aim of energy management in built facilities. A 16 node wireless sensor network was set up to monitor ambient temperature at various locations in MIT. A console application was developed in the C# language to collect temporal sensor data and store it in a SQL database. The application also provides a management system for fire hazard warnings by sending e-mails and calling mobile phones. An ASP.NET web application is then developed to retrieve temperature data over Internet. The data is accessible in different formats-table, XML and visualized in graphical form. This application lets the user register their phone numbers and e-mails to be informed in case of a fire emergency or excessive heating/cooling. A mobile application is developed on top of the web application to increase the range of data access to handheld Internet enabled telephony devices such as mobile phones and PDAs.<br>(cont.) The web access is implemented in XHTML-MP with a .NET web service and J2EE web service client back end. A desktop application is then used to access the real time temperature data through a PC desktop connected to the Internet. Spatial representation of data is visualized by overlaying the temperature profiles with floor plans and maps of the buildings using GIS.<br>by Piyush Hari.<br>S.M.
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Spreeth, Gideon. "Design of a low power wireless sensor network for environmental monitoring." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/1606.
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Thesis (MScEng (Electrical and Electronic Engineering))--Stellenbosch University, 2008.<br>A WSN (wireless sensor network) consists of a collection of small, low power electronic
devices that can sense their environment and communicate with each other in order to
send data to a base station for logging and monitoring. Research done on WSNs has
increased rapidly over the past few years, as the necessary RF hardware has become
cheaper and smaller. The wealth of information and hardware available in this field has
made it possible to design and deploy networks for a multitude of monitoring purposes,
on almost any terrain, without an existing telecommunication infrastructure.
This thesis presents research into some major aspects of WSNs and the implementation of
a test system with wireless sensor motes, that can be used for environmental monitoring,
conservation purposes, impact studies, early warning systems for floods, fires etc. The
system also has a wide range of possible uses in agriculture, as more data and better
control over crops can increase yield.
The power constraint of sensor nodes is one of the biggest concerns, as batteries can
be depleted quickly and render a system useless. For this reason, work was focused on
reducing power consumption of the hardware by means of various methods. Power use was
also simulated very successfully, giving a accurate way of predicting node lifetime with
a variety of battery types. The system was implemented on the Tmote Sky hardware
platform using the open source sensor network operating system, TinyOS.
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Bader, Sebastian. "On the lifetime and usability of environmental monitoring wireless sensor networks." Doctoral thesis, Mittuniversitetet, Avdelningen för elektronikkonstruktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-20046.
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Wireless sensor networks have been demonstrated, at an early stage in their development, to be a useful measurement technology for environmental monitoring applications. Based on their independence from existing infrastructures, wireless sensor networks can be deployed in virtually any location and provide sensor samples in a spatial and temporal resolution, which otherwise would only be achievable at high cost or involve significant work by humans.The feasibility of the usage of wireless sensor networks in real-world applications, however, is only maintained if certain technological challenges are overcome. Amongst these challenges, are the limited lifetime of the distributed sensor nodes, and user interfaces, which allow for the technology to be utilized in an efficient manner. Contributions to the solution of these challenges have been the objective of this thesis. After an analysis of the contributions wireless sensor networks can provide to the application domain of environmental monitoring, and the introduction to the restrictions, which are posed by a limited operational lifetime and low system usability, these issues are addressed at the system level of sensor nodedevices. The lifetime of sensor nodes, which is closely linked to the lifetime of the complete wireless sensor network, is addressed with regards to the energy efficiency of nodes, as well as the utilization of solar energy harvesting in order to increase the available energy resources. With respect to energy efficiency, an analysis has been performed of the contributions to the energy consumption of environmental monitoring sensor nodes, which leads to the desire to minimize the nodes' duty cycles and quiescent currents. A sensor node design is presented, which features energy efficiency as a key attribute by utilizingmodern semiconductor architectures. Moreover, an argument for the usage of synchronization-based, contention-free communication is made in order to reduce active communication periods and, thus, the duty cycle of a sensor node. A synchronization method with its focus on low protocol overhead is introduced as a basis for such communication forms. After an initial feasibility study in relation to using battery-less solar energy harvesting architectures in locations with limited solar irradiation, multiple architectural implementations are analyzed in a comparative manner. Among these comparisons is an analysis of short-termenergy storage devices in the form of double-layer capacitors and thin-film batteries, which provide prolonged component lifetimes than those for conventional secondary batteries, but which can only buffer for short periods of time due to their limited energy capacity. In order to be able to dimension such energy harvesting systems with respect to the individual application constraints at hand, state of charge simulations are proposed. Amethod for such simulations is presented and demonstrated for the implementation of an energy harvester model on a component basis. While the modeling in this manner is time consuming, the model can predict the state of charge of the energy buffer in the architecture with a high level of accuracy. Finally, a method for the systematic evaluation of solar energy harvesting architectures is presented. The presented method can be summarized as a solar energy harvesting testbed, which utilizes configurable energy harvesting circuits in order to create a deploy-once-test-many type of system. The output results of this testbed can significantly improve the efficiency of architecture comparisons and system modeling. Contributions to the improvement of the usability of wireless sensor nodes are made on two separate levels, namely, developer usability and end user usability. A method for the programming of sensor nodes based on hierarchical finite state machines is presented, which improves the usability of software development by creating familiarity for technically experienced users. Moreover, the utilization of finite state machine principles allows for the software to be developed in a systematic andmodular manner. As implemented applications typically require to be verified, which, in the environmental monitoring domain, usually results in outdoor deployments, usability considerations for sensor nodes are presented, which can simplify this process. Special attention has been paid in order for these improvements to be achieved with low overheads. While software development is a familiar concept for most system developers, this is not the case for the end users of these systems, who are typically domain experts. In order to allow for wireless sensor nodes to be operated by domain experts, a method for the configuration of sensor nodes has been proposed.The method uses a combination of graphical specification of the node behavior and a configurable sensor node. Theevaluation of this method, which has been based on a proof-of-concept implementation, demonstrated that the performance can remain high, while end users, without technical experience, are enabled to configure sensor nodes without prior training. In summary, the contributions, presented in this thesis, address system lifetime and usability with regards to the sensor node level. The results have led to the implementation of an energy efficient sensor node, which allows for the operation frombattery-less solar energy harvesting sources. Furthermore, support tools for the implementation of these nodes, both on the hardware and software level, have been proposed.
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Dowker, Kenneth Paul. "Long period fibre grating as gas sensor for environmental pollution monitoring." Thesis, Sheffield Hallam University, 2003. http://shura.shu.ac.uk/19578/.
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The principle objective of the work presented in this thesis is to investigate and demonstrate the possibility of utilising the inherent properties of long-period gratings (LPGs) to detect the existence and concentration of a given gas in the region immediately surrounding the fibre cladding. The principle and the viability of using LPGs for sensor applications is supported by the preliminary results reported here. However, the sensitivity of the sensor requires further improvement before it can in any way challenge the existing sensors in this field. The operational characteristics and limitations of existing optical sensors are reviewed and the advantages of a LPG based optical sensor highlighted. Thorough explanations of the theory and principles of light propagation, mode formation, and mode coupling in optical fibres are presented. Computer simulations predicting the optical effects due to changes in ambient indices from theoretical conditions are successfully derived, confirming the results obtained by experimental investigation. Various established coating methods are investigated and utilised in the application of optically sensitive compounds adsorbed onto the cladding with different levels of success, the poly-electrolyte self assembly (PESA) and evaporation methods proving most suitable. A novel method of monitoring the build up of PESA layers in-situ using surface plasmon resonance (SPR) methods is introduced. The coating chemicals used in this investigation showed some optical sensitivity at the optimum wavelengths used in optical fibres to the various gases being monitored, in most cases causing a detectable change in the optical characteristics of the modes in the LPG.This study has shown the possibility of using a suitably prepared LPG as a gas sensor. The LPG is coated with a chemical whose refractive index is changed by absorption of a given gas and thus the change in the coupling wavelengths being caused by the existence of the gas. Maximum shifts in coupling wavelength of +/-1.5 nm for relatively high gas concentrations are observed. The possibility of using a coating material which absorbs water, or surrounding the LPG with a suitable liquid is also demonstrated, the refractive index of the coating or liquid and thus the coupling wavelength shift being affected by the reaction of the gas. The possibility of using a single temperature immune LPG for ambient index sensing by observing different coupling wavelengths in the same grating is also reported.
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Ntshongontshi, Nomaphelo. "Molecularly imprinted polymer sensor systems for environmental estrogenic endocrine disrupting chemicals." University of the Western Cape, 2018. http://hdl.handle.net/11394/6241.
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Philosophiae Doctor - PhD (Chemistry)<br>There is growing concern on endocrine disrupting compounds (EDCs). The presence of drugs
in water supplies was first realized in Germany in the early 1990s when environmental
scientists discovered clofibric acid. Clofibric acid has the ability to lower cholesterol in ground
water below a water treatment plant. Endocrine disrupting compounds can be defined as those
chemicals with the ability to alter daily functioning of the endocrine system in living organisms.
There are numerous molecules that are regarded or referred to as EDCs such as but not limited
to organochlorinated pesticides, industrial chemicals, plastics and plasticizers, fuels, estrogens
and many other chemicals that are found in the environment or are in widespread use. 17?-
estradiol is the principal estrogen found in mammals during reproductive years. Estriol is
produced in large quantities during pregnancy. 17?-estradiol is the strongest, estriol the
weakest. Estriol is water soluble, estrone and estradiol are not. Although estrogen is produced
in women they are also at risk of over exposure to estrogen. Pesticides are extensively used
today in agricultural settings to prevent and control pests. Various pesticides, including banned
organochlorines (OCs) and modern non-persistent pesticides, have shown the ability to disrupt
thyroid activity, disturbing the homeostasis of the thyroid system. Because these EDCs have
adverse effects on health of both human and wildlife, it is imperative to develop viable costeffective
analytical methods for the detection of these EDCs in complicated samples and at
very low concentrations. Very high selectivity towards particular compounds is a very
important property for the suitability of a detection method. This is because these compounds
mostly coexist in complex matrices which makes the detection of a specific compound very
challenging. It is paramount to develop highly sensitive and selective methods for the detection
of these estrogens and phosphoric acid-based pesticides at trace levels.<br>2021-08-31
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Cheekiralla, Sivaram M. S. L. 1980. "Development of a wireless sensor unit for tunnel monitoring." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/30043.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004.<br>Includes bibliographical references (p. 133-138).<br>In this thesis we describe the development of a wireless sensor module for tunnel monitoring. The tunnel in question is a part of the London Underground system. Construction of a new tunnel beneath the existing tunnel is anticipated to cause quantifiable vertical displacement. To ensure safe operation of the tunnel during the construction activity, a real-time monitoring system has been created to measure vertical displacements along the critical zone near Highbury & Islington station. A geomechanical analysis, provided by a third party, is used to establish the allowable maximum displacement. A custom wireless sensor module was developed from off-the-shelf components. This module consists of a sensor device, microcontroller, ADC and RF transmitter. The integration of these components is described in detail. Deployment details and some preliminary results are presented.<br>by Sivaram M.S.L. Cheekiralla.<br>S.M.
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Ber, Marti Jordi 1976. "Innovation in the AEC industry through wireless sensor networks." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/31122.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2005.<br>"June 2005."<br>Includes bibliographical references (leaves 67-69).<br>I came to the Massachusetts Institute of Technology (MIT) to learn about technological innovation and entrepreneurship. More precisely, I wanted to know more about how to leverage Information Technology (IT) in the Architecture, Engineering and Construction (AEC) Industry. IT can introduce great efficiencies and productivity gains in construction.<br>by Jordi Ber Marti.<br>M.Eng.
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Song, Heewon 1977. "Implementing a wireless base station for a sensor network." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/30047.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004.<br>Includes bibliographical references (leaves 68-69).<br>Using wireless sensor networks for monitoring infrastructure is a new trend in civil engineering. Compared with traditional ways to monitor infrastructure, wireless sensor networks are cheap, safe, and compact. However, there are many available wireless communication techniques and hardware for a wireless sensor network. Therefore, it is an important step to choose the best communication method and hardware to construct a wireless sensor network for a particular infrastructure. The London Underground project, which is described in this thesis as a reference case study, demands real-time data transmission, low-power network, and wireless network communication, and also a hardware/software system to collect, archive and display data from the monitoring activity. We consider the trade-offs in choosing 802.1 lb as a communication method. A web service architecture for data visualization is then described. Finally we discuss the appropriate selection of a computer device to serve as the base station.<br>by Heewon Song.<br>M.Eng.
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Kokossalakis, George 1976. "Acoustic data communication system for in-pipe wireless sensor networks." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/34379.
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Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2006.<br>Includes bibliographical references.<br>Sustainability of aging infrastructure is one of the greatest current civil engineering challenges, especially in the case of pipelines, where no direct access is available. Being simultaneously massive and distributed, their normal operation is critical for the health and prosperity of the community. In current practice, the condition of pipelines is assessed by non-destructive inspection techniques. Nonetheless, frequent pipeline failures warrant the continuous assessment of their condition, in order to schedule the maintenance activities accordingly, and assure their safe operation. Continuous monitoring necessitates the deployment of autonomous wireless sensor networks (WSN). This thesis proposes solutions for the communication and power units of a WSN for monitoring underground water pipelines. Regarding the communication unit, it is proposed to use the pipeline as an acoustic waveguide for the transmission of appropriately modulated acoustic waves that encapsulate the digital data, since radio frequency transmission is not feasible underground. The confined acoustic channel imposes severe distortion on the propagating signal. In order to compensate for the dispersion and ambient noise, the proposed communication system employs an elaborate set of signal processing steps, such as Reed-Solomon Encoding, Barker Code Synchronization, Adaptive Equalization, Bandpass Filtering, Stacking and application of Inverse Transfer Function techniques. The robust performance of the proposed system is evaluated and verified by means of numerical simulations and scaled laboratory experiments.<br>(cont.) The bandwidth vs. power relationship is identified as the major trade-off for its design, since the in-pipe acoustic channel is bandwidth limited, while the WSN application is power limited. Excessive bandwidth use would impose severe distortion on the propagating signal, while power limitations restrict the use of bandwidth efficient digital communication techniques. In order to address the power availability, a miniature power harvesting system, extracting energy from the flow of water inside the pipeline, is proposed, composed of a generator and a turbine combination. A hybrid design presenting the high efficiency of Gorlov's helical turbine and the high startup torque of Savonius turbine is provided. The resulting power harvesting system is capable of sustaining a continuous 1 watt of power under normal water pipeline operating conditions.<br>by George Kokossalakis.<br>Sc.D.
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Greene, David C. (David Carl) 1978. "Sensor technology and applications to a real-time monitoring system." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8616.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.<br>Includes bibliographical references (p. 85-87).<br>Large-scale structures such as bridges, dams and buildings have caused countless fatalities in the past decades because engineers were not able to detect the early signs of failure. It is believed that with the implementation of a distributed sensor network, many of these unfortunate events could have been avoided. The ultimate goal in applying distributed sensors is for structures to combine mechanical systems and computer processing to allow them to adapt themselves in extreme conditions without human assistance. The Flagpole project is attempting to build such a monitoring system by instrumenting a model of a flagpole in a laboratory environment. The selected sensors, accelerometers, strain gauges and thermocouples, provide a complete description of the model's behavior to the physical environment. These sensors stream data into a data acquisition system, which buffers the data and directs it to a database for storage. Visualization software allows for Internet users to view the data in real-time and analyze the model's reaction to current external forces. For this system to become more automated, new sensor technology must be explored. Recent advances in the field of MEMS technology and wireless communication should be examined to build a system that incorporates decision-making at the sensor level and is expandable to larger scale systems.<br>by David C. Greene.<br>M.Eng.
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Williams, Adrienne Dee. "DNA-Nucleobase Guanine as Passivation/Gate Dielectric Layer for Flexible GFET-Based Sensor Applications." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1440775088.
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Cianci, Christopher Michael. "Distributed intelligent algorithms for robotic sensor networks monitoring discontinuous anisotropic environmental fields /." Lausanne : EPFL, 2009. http://library.epfl.ch/theses/?nr=4247.
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Thèse Ecole polytechnique fédérale de Lausanne EPFL, no 4247 (2009), Faculté informatique et communications IC, Programme doctoral Informatique, Communications et Information, Institut des sciences et technologies de l'environnement ISTE (Laboratoire de systèmes et algorithmes intelligents distribués DISAL). Dir.: Alcherio Martinoli.
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Canhoto, Olinda. "Applications of volatile fingerprint sensor arrays for rapid detection of environmental contaminants." Thesis, Cranfield University, 2005. http://hdl.handle.net/1826/919.
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The electronic nose (e-nose) technology has rapidly evolved in the past decade with a range of applications in the food industry, medical diagnosis, and recently environmental monitoring. This is the first time that this technology has been examined in detail for a range of specific environmental applications including: detection of low concentrations of bacterial, fungal and heavy metal contaminants in potable water; analyses of changes in the microbial activity of soil samples amended with heavy metals; and the detection of fungal contaminants in paper samples from library material. In some studies comparisons between different e-nose systems has also been carried out.
The e-nose system based on a conducting polymer (CP) sensor array Bloodhound (BH114) was able to detect different bacterial species (Escherichia coli, Pseudomonas aeruginosa and Enterobacter aerogenes), initially inoculated in tap, reverse osmosis and bottled water with a concentration of 102 cells mL-1, after 24 hrs incubation. In the presence of low concentrations (0.5 ppm) of a mixture of heavy metal ions including cadmium, lead and zinc, the volatile pattern produced by the bacterial species was discriminated from that where no metal was added, probably due to a change in the microbial metabolism.
The Bloodhound e-nose system was also used to detect fungal spores of Aspergillus fumigatus, Fusarium culmorum and a Penicillium species, inoculated in water samples. The initial concentrations were 102 – 105 spores mL-1. Good discrimination was observed between the control samples after 24 hrs incubation at 25oC. After 48 hrs incubation, it was possible to differentiate between the various spore concentrations present in water samples. Good reproducibility was achieved as results from different days were consistent and data could be pooled and combined for analysis.
A comparative study was performed with three e-nose instruments, two of them had CP sensor arrays (Bloodhound (BH-114); Neotronics (eNOSE 4000), and the third was a metal oxide (MO) sensor-based system, the NST 3220. The experiments carried out
with the CP based-systems showed similar results when analysing water samples contaminated with 104 and 102 bacterial cells mL-1 after 24 hrs incubation. Both CP and MO based e-nose systems could differentiate control water samples from those contaminated with both bacteria and fungal spores. GC-SPME analyses confirmed the results obtained with the e-nose system of metal ions and bacterial cells in water samples.
At-line studies were performed with the MO array-based system (NST 3220), for the detection of contamination episodes. E. coli and P. aeruginosa cells were used as contamination agents for tap and reverse osmosis sterile water, in two concentration levels, 102 and 106 cells mL-1. The samples collected downstream in a simulated watercourse, were analysed by the e-nose over a period of 1-2 hrs. The results suggested the potential of this technique to monitor episodes of bacterial cells at a low concentration in water samples.
Experiments performed in soil samples artificially and naturally contaminated with heavy metal ions were analysed with the MO-based e-nose system. Results indicated that for artificially contaminated soil samples, after 40 days incubation the control samples could be discriminated from those containing 3 and 100 ppm of metal ions. For naturally contaminated soils, the sensor array was only able to separate samples containing a high concentrations of metal ions.
Headspace analysis of cellulose-based agar showed good discrimination between Aspergillus terreus, A. hollandicus and Eurotium chevallieri, after 20 hrs incubation at 25oC. An increase in the incubation period to 40 hrs resulted in better separation between the control and fungal treatments. In situ studies performed on paper samples suggested that the e-nose was able to discriminate between control samples and paper inoculated with 103 fungal spores mL-1. The substrate was a determinant factor in the headspace analysis of microbial species. It was shown that the same fungal species produced different volatile profiles according to the growth substrate.
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Roberts, Darrin F. "An environmental assessment of sensor-based variable-rate nitrogen management in corn." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4544.
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Thesis (M.S.) University of Missouri-Columbia, 2006.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 26, 2007) Includes bibliographical references.
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YU, JINSONG. "Development of Microfabricated Electrochemical Sensors for Environmental Parameter Measurements Applicable to Corrosion Evaluation and Gaseous Oxygen Detection." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1206981091.
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Koch, John R. "A hybrid sensor network for watershed monitoring." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2008. http://scholarsmine.mst.edu/thesis/pdf/jrk4y8_09007dcc804f8fe6.pdf.
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Thesis (M.S.)--Missouri University of Science and Technology, 2008.<br>Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 27, 2008) Includes bibliographical references (p. 84-86).
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Zhou, Yuhua Ph D. Massachusetts Institute of Technology. "Multi-sensor large scale land surface data assimilation using ensemble approaches." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/34610.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2006.<br>Includes bibliographical references (p. 223-234).<br>One of the ensemble Kalman filter's (EnKF) attractive features in land surface applications is its ability to provide distributional information. The EnKF relies on normality approximations that improve its efficiency but can also compromise the accuracy of its distributional estimates. The effects of these approximations are evaluated by comparing the conditional marginal distributions and moments estimated by the EnKF to those obtained from an SIR particle filter, which gives exact solutions for large ensemble sizes. The results show that overall the EnKF appears to provide a good approximation for nonlinear, non-normal land surface problems. A difficulty in land data assimilation problems results from the high dimensionality of states created by spatial discretization over large computational grids. The high dimensionality can be reduced by exploiting the fact that soil moisture field may have significant spatial correlation structure especially after extensive rainfall while it may have local structure determined by soil and vegetation variability after prolonged drydown. This is confirmed by SVD of the replicate matrix produced in an ensemble forecasting experiment. Local EnKF's are suitable for problems during dry periods but give less accurate results after rainfall.<br>(cont.) The most promising option is to develop a generalized method that reflects structural changes in the ensemble. A highly efficient ensemble multiscale filter (EnMSF) is then proposed to solve large scale nonlinear estimation problems with arbitrary uncertainties. At each prediction step realizations of the state variables are propagated. At update times, joint Gaussian distribution of states and measurements are assumed and the Predictive Efficiency method is used to identify a multiscale tree to approximate statistics of the propagated ensemble. Then a two-sweep update is performed to estimate the state variables using all the data. By controlling the tree parameters, the EnMSF can reduce sampling error while keep long range correlation in the ensemble. Applications of the EnMSF to Navier-Stokes equation and a nonlinear diffusion problem are demonstrated. Finally, the EnMSF is successfully applied to soil moisture and surface fluxes estimation over the Great Plains using synthetic multiresolution L-band passive and active microwave soil moisture measurements following HYDROS specifications.<br>by Yuhua Zhou.<br>Ph.D.
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Iyiola, Samuel Oluwagbemi. "Moteino-Based Wireless Data Transfer for Environmental Monitoring." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984271/.
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Data acquisition through wireless sensor networks (WSNs) has enormous potential for scalable, distributed, real-time observations of monitored environmental parameters. Despite increasing versatility and functionalities, one critical factor that affects the operation of WSNs is limited power. WSN sensor nodes are usually battery powered, and therefore the long-term operation of the WSN greatly depends on battery capacity and the node's power consumption rate. This thesis focuses on WSN node design to reduce power consumption in order to achieve sustainable power supply. For this purpose, this thesis proposes a Moteino-based WSN node and an energy efficient duty cycle that reduces current consumption in standby mode using an enhanced watchdog timer. The nodes perform radio communication at 915 MHz, for short intervals (180ms) every 10 minutes, and consume 6.8 mA at -14dBm. For testing, the WSN node monitored a low-power combined air temperature, relative humidity, and barometric pressure sensor, together with a typical soil moisture sensor that consumes more power. Laboratory tests indicated average current consumption of ~30µA using these short radio transmission intervals. After transmission tests, field deployment of a star-configured network of nine of these nodes and one gateway node provides a long-term platform for testing under rigorous conditions. A webserver running on a Raspberry Pi connected serially to the gateway node provides real-time access to this WSN.
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Bigham, Daniel. "Calibration and testing of a wireless suspended sediment sensor." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/13798.
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Master of Science<br>Department of Biological and Agricultural Engineering<br>Naiqian Zhang<br>A real time wireless, optical sensor network was tested for long-term, remote monitoring of suspended sediment concentrations (SSC) in streams. The sensor and control board assembly was calibrated using a two-stage calibration procedure, including a pre-calibration conducted in the laboratory to adjust the sensitivity of the sensor and a field calibration using grab samples to establish an effective statistical model to predict SSC from the sensor signals. The assembly was installed in three military bases around the United States. These bases were Fort Riley, Kansas; Fort Benning, GA; and Aberdeen Proving Ground, MD. The types of water bodies and watersheds varied greatly among the sites, which allowed the sensor to be tested under versatile conditions for potential widespread use.
The results show that the sensor was capable of measuring SSC at each watershed independently. The calibration model developed for each sensor can be used to predict SSC from real-time sensor data. A data processing algorithm was developed to lessen the effect of fouling and clogging on sensor signals, along with eliminating anomalies in the data gathered. The results of this study displayed meaningful prediction data that can be used to estimate SSC in a stream over a long period of time. Information obtained in this study can be used as a launching point for future work and understanding of stream processes.
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Yang, Jue. "Design and Implementation of Large-Scale Wireless Sensor Networks for Environmental Monitoring Applications." Thesis, University of North Texas, 2010. https://digital.library.unt.edu/ark:/67531/metadc28493/.
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Environmental monitoring represents a major application domain for wireless sensor networks (WSN). However, despite significant advances in recent years, there are still many challenging issues to be addressed to exploit the full potential of the emerging WSN technology. In this dissertation, we introduce the design and implementation of low-power wireless sensor networks for long-term, autonomous, and near-real-time environmental monitoring applications. We have developed an out-of-box solution consisting of a suite of software, protocols and algorithms to provide reliable data collection with extremely low power consumption. Two wireless sensor networks based on the proposed solution have been deployed in remote field stations to monitor soil moisture along with other environmental parameters. As parts of the ever-growing environmental monitoring cyberinfrastructure, these networks have been integrated into the Texas Environmental Observatory system for long-term operation. Environmental measurement and network performance results are presented to demonstrate the capability, reliability and energy-efficiency of the network.
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Xu, Guoxiang. "Environmental Remediation with Fenton Reagents and Synthesis of a Novel Halide Fluorescence Sensor." ScholarWorks@UNO, 2005. http://scholarworks.uno.edu/td/144.
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Suwannee River fulvic acid (SRFA) and humic acid (SRHA) were used as dissolved organic matter (DOM) and were applied to probe the effect of DOM. Addition of DOM resulted in decreased first order rate constants for all species selected. The inhibition became more significant as the hydrophobicity of the species increased. The decrease could not be simply attributed to the binding of hydrophobic species to DOM. This can be explained by the physical isolation of iron (II), which binds to hydrophilic sites of DOM and is the hydroxyl radical generation site, from hydrophobic pollutants which bind to hydrophobic sites of DOM. Accordingly, species which could compete agains t this physical isolation by DOM and bring iron (II) closer to target species could increase the degradation rates. This was observed with application of carboxymethyl-ß-cyclodextrin (CMßCD). Effects from concentration, structure of the target species and acidity etc., were studied. The increased degradation rates were observed even in the presence of DOM. Studies on ternary complexes of hydrophobic pollutants, iron (II) and CMßCD were carried with ESMS, UV and Fluorescence experiments and further calix[6]arene derivatives. Along with the fact that CMßCD can increase the solubility of hydrophobic species and remove them from contaminated sites, this indicates a potential application to in-situ degradation systems. Initial two -phase studies were carried out with quartz sand deposited with polycholobiphenyl (PCBs) and polycyclic aromatic hydrocarbons (PAHs). Successful degradations were observed with PCBs but not PAHs. The difference is attributed to the slow equilibrium of sorbed PAHs with dissolved CMßCD and the higher PAH loading used in these experiments. A halide sensor-molecule (1, 8-diphenylureaylnaphthalene), which performs with increasing fluorescence in the presence of fluoride and decreasing fluorescence with all other halides, was synthesized and reported. Studies using NMR and computer modeling with SPARTAN were carried out to compare the sensor-molecule with an analog, 2, 3-diphenylureaylnaphthalene. Both studies indicated that only fluoride can be accommodated in the space between the urea group protons to form a strong interaction. The sensor-molecule could to lead to improved sensors that overcome limitations with current fluorescence-quenching based anion sensors.
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Sendra, Compte Sandra. "Deployment of Efficient Wireless Sensor Nodes for Monitoring in Rural, Indoor and Underwater Environments." Doctoral thesis, Editorial Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/32279.
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Existen muchos trabajos relacionados con el diseño y desarrollo de nodos sensores, donde se presentan gran variedad de aplicaciones. Las redes de sensores inalámbricos pueden facilitarnos y mejorar algunos aspectos de nuestra vida diaria. Es fácil, pensar que si este tipo de dispositivo es tan beneficioso para nosotros y para el entorno donde vivimos, su precio debería ser relativamente barato. Pero podemos comprobar que esto no es así. ¿Por qué estos dispositivos son tan caros? ¿Sería posible desarrollar dispositivos con las mismas capacidades y precios más económicos? ¿Cómo puedo fabricar mis nodos sensores de bajo coste?
Esta tesis responde a estas preguntas y muestra algunas de las muchas aplicaciones que los nodos sensores pueden tener. En esta tesis hemos propuesto (e implementado en algunos casos) el desarrollo de nodos sensores para la monitorización del medio, a partir de dispositivos de bajo coste. Para la implementación de un nodo sensor, y en definitiva la red que une a todos estos nodos, es importante conocer el medio donde trabajarán. A lo largo de este documento se presentan las investigaciones llevadas a cabo para el desarrollo de sensores en tres ámbitos de aplicación.
En el primero de ellos, se desarrollan dispositivos multisenores para la monitorización del medio. La aplicación de las redes de sensores inalámbricas al medio natural, precisa un estudio de cómo se ven afectadas las señales, en función de la distancia, vegetación, humedad del ambiente, etc. Focalizamos nuestros desarrollos en la verificación de incendios en zonas rurales y en el control de plagas en viñedos donde la detección precoz de estos eventos genera elevados ahorros económicos. También proponemos el desarrollo de una red de collares sensores para ganado domestico, que nos ayudará a reducir y prevenir en muchos casos, los ataques de lobos y hurtos de crías. Por último, dentro de este grupo, presentamos una red permite detectar anomalía de los materiales en edificios y red de sensores que nos permite monitorizar las personas mayores o deficientes, que se mueven junto con un grupo, en una excursión o actividad.
El segundo grupo de aplicaciones, hace referencia a la monitorización de espacios en entornos de interior. Para ello hemos analizado el comportamiento de las señales inalámbricas en diferentes escenarios. Los resultados, nos han permitido extraer un nuevo método de diseño de las redes inalámbricas en interiores. Nuestro método, permite definir la mejor ubicación de los dispositivos de red y nodos sensores en interiores con un ahorro en el número de sensores del 15%.
Por último, se presenta el estudio sobre las comunicaciones subacuáticas basadas en las ondas electromagnéticas donde analizamos la dependencia de las comunicaciones subacuáticas en agua dulce en función de la frecuencia, temperatura, tasas de transferencia de datos y modulación.
Relacionado con el medio subacuático, presentamos 2 propuestas. La primera de ellas hace referencia a la implementación de una red de sensores para granjas marinas que nos permite reducir la cantidad de residuos depositados en el lecho marino y reducir el porcentaje de comida desperdiciada. La segunda propuesta es el desarrollo de dos sensores oceanográficos que nos permitirían controlar la cantidad de comida y heces depositadas en el suelo y controlar la turbidez del agua de manera muy simple y económica
Todos estos desarrollos y propuestas, han estado precedidos por un exhaustivo estudio sobre los problemas energéticos que las redes de sensores inalámbricas presentan y las técnicas que pueden emplearse, para prolongar la vida útil de la red y mejorar su estabilidad.<br>There are many works related to the design and development of sensor nodes which present
several applications. Wireless sensor networks can facilitate and improve some aspects of our daily
lives. It is easy to think that if this type of device is so beneficial to us and to our environment, its
price should be relatively cheap. But we can see that this is not true. Why these devices are so
expensive? Would it be possible to develop devices with the same capabilities and lower prices?
How can I make my low-cost sensor nodes?
This dissertation answers these questions and shows some of the many applications that sensor
nodes may have. In this dissertation, we propose (and implement in some cases) the development of
sensor nodes for environmental monitoring, from low-cost devices. For the implementation of a
sensor node and network which joins all these nodes, it is important to know the environment where
they will work. Throughout this dissertation, we present the research carried out for the
development of sensors in three main application areas.
In the first of these areas, we present multisensor devices developed for environmental
monitoring. The application of wireless sensor networks to the environment requires a study of how
signals are affected depending on the distance, vegetation, ambient humidity, etc. We focus our
developments on the fire detection in rural areas and on the control of pests in vineyards where the
early detection of these events generates high economic savings. We also propose the development
of a sensor network which will help us to reduce and prevent wolves¿ attacks and theft in livestock.
Finally, within this group, we present a network to detect material anomalies in building and a
sensor network which allows us to monitor the elderly or disabled people who move along with a
group on a tour or activity.
The second group of applications is related to the monitoring of spaces in indoor environments.
For this, we analyze the behavior of wireless signals in different scenarios. These results allowed us
to extract a new method for designing wireless networks in indoor environments. Our method
allows defining the best location of network devices and sensor nodes indoors saving 15% of the
sensors needed.
Finally, we present a study on underwater freshwater communications based on electromagnetic
waves, where we analyze the dependency of underwater communications as a function of working
frequency, temperature, data transfer rates and modulation.
Related to underwater environment, we present two proposals. First one refers to the
implementation of a sensor network for marine farms which allows us to reduce the amount of
waste deposited on the seabed and reduce the percentage of wasted food. The second proposal is the
development of two oceanographic sensors which allow us to control the amount of food and feces
deposited in seabed and the water turbidity control in a very simple and inexpensive way.
All these developments and proposals have been preceded by a comprehensive study on the
energy problems in wireless sensor networks. We have also presented several techniques which can
be used to prolong the network lifetime and improve its stability.<br>Sendra Compte, S. (2013). Deployment of Efficient Wireless Sensor Nodes for Monitoring in Rural, Indoor and Underwater Environments [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32279<br>Alfresco