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Title
Design and deployment of low-cost wireless sensor networks for real-time event detection and monitoring
Creator
Phillips, Dennis Edward
Date
2018
Collection
Electronic Theses & Dissertations
Description
As sensor network technologies become more mature, they are increasingly being applied to a wide variety of environmental monitoring applications, ranging from agricultural sensing to habitat monitoring, oceanic and volcanic monitoring. In this dissertation two wireless sensor networks (WSNs) are presented. One for monitoring residential power usage and another for producing an image of a volcano's internal structure.The two WSNs presented address several common challenges facing modern...
Show moreAs sensor network technologies become more mature, they are increasingly being applied to a wide variety of environmental monitoring applications, ranging from agricultural sensing to habitat monitoring, oceanic and volcanic monitoring. In this dissertation two wireless sensor networks (WSNs) are presented. One for monitoring residential power usage and another for producing an image of a volcano's internal structure.The two WSNs presented address several common challenges facing modern sensor networks. The first is in-network processing and assigning the processing tasks across a heterogeneous network architecture. By efficiently utilizing in-network processing power consumption can be reduced and operational lifetime of the network can be extended. As nodes are embedded into various environments sensing accuracy is intrinsically affected by physical noise. The second challenge relates to how to deal with this noise in a way which increases sensing accuracy. The third challenge is ease of deployment. As WSNs become more common place they will be installed by non-experts.As a key technology of home area networks in smart grids, fine-grained power usage monitoring may help conserve electricity. Smart homes outfitted with network connected appliances will provide this capability in the future. Until smart appliances have wide adaption there is a serious gap in capabilities. To fill this gap an easy to deploy monitoring system is needed. Several existing systems achieve the goal of fine-grained power monitoring by exploiting appliances' power usage signatures utilizing labor-intensive in situ training processes. Recent work shows that autonomous power usage monitoring can be achieved by supplementing a smart meter with distributed sensors that detect the working states of appliances. However, sensors must be carefully installed for each appliance, resulting in high installation cost. Supero is the first ad hoc sensor system that can monitor appliance power usage without supervised training. By exploiting multi-sensor fusion and unsupervised machine learning algorithms, Supero can classify the appliance events of interest and autonomously associate measured power usage with the respective appliances. Extensive evaluation in five real homes shows that Supero can estimate the energy consumption with errors less than 7.5%. Moreover, non-professional users can quickly deploy Supero with considerable flexibility.There are a number of active volcanos around the world with large population areas located nearby. An eruption poses a significant threat to the adjacent population. During times of increased activity being able to obtain a real-time images of the interior would allow seismologists to better understand volcanic dynamics. Volcano tomography can provide this valuable information concerning the internal structure of a volcano. The second sensor network presented in this dissertation is a seismic monitoring sensor network featuring in-network processing of the seismic signals with the capability to perform volcano tomography in real-time. The design challenges, analysis of processing/network processing times in the information processing pipeline, the system designed to meet these challenges and the results from deploying a prototype network on two volcanoes in Ecuador and Chile are presented. The study shows that it is possible to achieve in-network seismic event detection and real-time tomography using a sensor network that is 2 orders of magnitude less expensive than traditional seismic equipment.
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Title
Towards discrete-pulse-based networking and event detection architectures for resource-constrained applications
Creator
Das, Saptarshi (Graduate of Michigan State University)
Date
2019
Collection
Electronic Theses & Dissertations
Description
"In this dissertation thesis, we develop a scalable and energy-efficient discrete-pulse-based networking architecture along with a Spiking-Neuron-based low-power detection framework for use in resource-constrained settings. Applications such as Structural Health Monitoring (SHM) using wireless sensor networks powered by ambient energy harvesting are particularly suited for such a framework. The key idea in pulse-based networking is to eschew unnecessary overhead as incurred in traditional...
Show more"In this dissertation thesis, we develop a scalable and energy-efficient discrete-pulse-based networking architecture along with a Spiking-Neuron-based low-power detection framework for use in resource-constrained settings. Applications such as Structural Health Monitoring (SHM) using wireless sensor networks powered by ambient energy harvesting are particularly suited for such a framework. The key idea in pulse-based networking is to eschew unnecessary overhead as incurred in traditional packet-based networking and encode only the essential information using small number of discrete pulses and their positions with respect to a synchronized time frame structure. The baseline pulse networking does not scale well with increase in network size. In order to ameliorate this, we develop a scalable time frame structure for use in applications with large network size while preserving the energy advantages of pulse networking. In addition, we stress the importance of judicious use of erratic energy availability in ambient energy harvesting powered systems. To that effect, we build energy-awareness syntaxes within the pulse networking framework for better utilization of energy resources in such systems. We also demonstrate the feasibility of pulse networking over a through-substrate ultrasonic link layer and the advantages thereof in terms of utilizing existing infrastructure and removing the need for radio retrofits. We explore how the protocol performance varies for an airplane stabilizer monitoring application powered by ambient vibration energy harvesting in different energy availability scenarios. Beyond this, we also develop a Spiking-Neuron-based low-power event pattern detection architecture and illustrate how this can be incorporated within a pulse-networked SHM system. The Spiking Neuron based architecture is evidenced to be simpler in terms of implementation but more efficient in terms of computation and energy usage, thus enabling in-situ detection even at intermediate nodes in the network and robust low-power event pattern detection immune to pulse drifts and errors."--Pages ii-iii.
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Title
Wireless sensors for enhancing food supply chain visibility
Creator
Karuppuswami, Saranraj
Date
2019
Collection
Electronic Theses & Dissertations
Description
"The demand for providing safe and quality food from the farm to the plate had led to the development of sensor technologies for quality control and real-time end-to-end monitoring of food along the supply chain. These advanced sensors serve as the first line of defense against food-borne outbreaks, economically motivated adulteration, and food contamination preventing illness, deaths, huge economic losses and promotes global health and well-being. The key goal is to ensure that the food...
Show more"The demand for providing safe and quality food from the farm to the plate had led to the development of sensor technologies for quality control and real-time end-to-end monitoring of food along the supply chain. These advanced sensors serve as the first line of defense against food-borne outbreaks, economically motivated adulteration, and food contamination preventing illness, deaths, huge economic losses and promotes global health and well-being. The key goal is to ensure that the food reaching the fork meets the highest safety standards by promoting tamper-free sustainable practices along the food supply chain. Real-time food monitoring also prevents unnecessary wastage due to spoilage or good food being thrown out due to misconception of the labeled expiration date. In this dissertation, a number of RF passive wireless sensing approaches are presented that allows simultaneous tracking and quality monitoring of packaged food products as it moves along the supply chain. The end goal is to develop a low cost, long range, battery-free, and real time sensor tag which can detect multiple parameters of the packaged food simultaneously and at the same time provide the identification information. In order to realize a multi-functional sensor tag, a number of sensing approaches are developed targeting four different types of food related quality control challenges; Adulteration, Contamination, Wastage, and Spoilage. To identify and eliminate food adulteration, magnetoelastic based dielectric and viscosity sensors are developed. These hybrid sensors are shorter range sensors and a number of liquid food items such as milk and oil are characterized. A sensing approach that utilizes 3D printed RF sensors coupled to a microfludic channel for liquid profling by monitoring the dielectric constant is developed for food quality detection. Next, to prevent contamination, capacitance based short range inductor-capacitor (LC) tanks are developed. An interdisciplinary approach which is a confluence of carbohydrate coated nano particles capturing bacteria in liquid food with RF detection is developed. A common method to prevent wastage or spoilage is to detect and profile aroma emitted from food. Adsorption, absorption, and capillary condensation based short range as well as long range sensors that monitor the dielectric constant or the conductivity of the target food are developed. First, a short range capillary condensation based sensor is demonstrated for volatile profiling using a porous substrate and an LC tank. This is followed by demonstrating sensitivity and specificity of different thin-film coated short range sensors that detect vapors that are directly related to the spoilage index of the food. Finally, a long range passive sensor integrated with ID is demonstrated for detecting Ammonia in packaged food. The developed sensor is compatible with existing RFID infrastructure and is capable of digitizing the sensor information along with the identification information for transmission. Overall, the work demonstrates that a passive multi-modal sensor provides additional information about products moving across the supply chain transforming the tracebility-centric supply chain into a value-centric one with increased visibility and empowers the different stake holders with the quality information as the product moves along the supply chain."--Pages ii-iii.
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Title
Transmission timing modulation for information coding in energy-constrained wireless networks
Creator
Feng, Dezhi
Date
2020
Collection
Electronic Theses & Dissertations
Description
The objective of this thesis is to develop a framework of transmission timing-based modulation framework for improving energy efficiency, security, and information transfer capacity in embedded wireless networks with very thin energy budgets. The key idea is to modulate both intra-PDU (Protocol Data Unit) and inter-PDU timing for addressing energy, security, and information transfer capacity in wireless embedded networks. As for energy efficiency, we developed a novel pulse position-coded PDU...
Show moreThe objective of this thesis is to develop a framework of transmission timing-based modulation framework for improving energy efficiency, security, and information transfer capacity in embedded wireless networks with very thin energy budgets. The key idea is to modulate both intra-PDU (Protocol Data Unit) and inter-PDU timing for addressing energy, security, and information transfer capacity in wireless embedded networks. As for energy efficiency, we developed a novel pulse position-coded PDU (PPCP) paradigm. The core idea is to encode a protocol data unit (PDU) in terms of the silence duration between two sets of delimiter pulses, whose positions are modulated based on the value of the PDU. This PPCP architecture achieves significant energy savings by using a lesser amount of bit/pulse transmissions, and by eliminating long multi-bit preambles and headers, which are normally used in traditional packets. The proposed multi-access pulse-based PDU scheme enables medium sharing among many sensor nodes without requiring per-PDU frame synchronization. As for security, we developed the concept of a novel chaotic pulse position coded protocol data unit (CPPCP) for secure embedded networking. The core idea of CPPCP is to encode a protocol data unit (PDU) with a wideband pulse train with chaotically-varied inter-pulse intervals. The architecture ensures communication security by introducing randomness between data symbols, noise-like frequency spectrum, and significant energy savings by using a smaller number of pulse transmissions compared to existing secure coding schemes such as Bluetooth Low Energy (BLE). Compared with the traditional key-based cryptographic techniques, CPPCP suppresses decipherable information by eliminating symbol periodicity. The mechanism can also be piggy-backed on traditional cryptography solutions to achieve higher levels of security. Finally, for enhancing the information transfer capacity, we developed a data packet position modulation (DPPM) paradigm. Packet transmissions in low duty cycle networks are often scheduled as TDMA slots, whose periodicity is determined based on application sampling requirements and the energy in-flow, often in the form of energy harvesting. The key idea of DPPM is to modulate the inter-packet spacing for coding additional information without incurring additional transmission energy expenditures. We first developed a have a DPPM based networking solution for single-hop transmit-only networks in which a number of low-energy nodes transmit data to an aggregator. The architecture is developed for a two-node point-to-point link, followed by a multipoint-to-point multi-access network. Detailed analytical and simulation models are developed to demonstrate the performance of a symmetric and an asymmetric version of DPPM.
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