Energy e ciency is a critical constraint in wireless sensor networks. Wireless sensor networks (WSNs) consist of a large number of battery-powered sensor nodes, connected to each other and equipped with low-power transmission radios. Usually, the sensor nodes closer to the sink are more likely to become overloaded and subject to draining their battery faster than the nodes farther away, creating a funneling e ect. The use of a mobile device as a sink node to perform data gathering is a well known solution to balance the energy consumption in the entire network. To address this problem, in this work we consider the use of an UAV as a mobile sink. An unmanned aircraft vehicle (UAV) is an aircraft without a human pilot on-board, popularly known as a Drone. In this thesis, besides the use of the UAV as a mobile sink node, we propose an UAV-aided algorithm for data gathering in wireless sensor networks, called Humming- bird. Our distributed algorithm is energy-e cient. Rather than using an arbitrary path, the UAV implements an approximation algorithm to solve the well-known NP- Hard problem, the Traveling Salesman Problem (or TSP), to setup the trajectory of node points to visit for data gathering. In our approach, both the path planning and the data gathering are performed by the UAV, and this is seamlessly integrated with sensor data reporting. The results, using ns-3 network simulator show that our algorithm improves the network lifetime compared to regular (non-UAV) data gathering, especially for data intensive applications. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

A method for modeling and simulating neural action potential (AP) propagation along the length of an axon containing a number of Ranvier nodes is proposed in this dissertation. A system identification approach is adopted to represent node of Ranvier (NR) response to current pulse stimulus in the form of transfer function representations for NR excitability. Segments of myelinated internodal (IN) and NR regions are cascaded, representing the remaining downstream axon after a site-of-stimulus introduction of an external current pulse. This cascading network is used to simulate "cable" properties and signal propagation along the length of the axon. This work proposes possible solutions to attenuation losses inherited in the classical myelinated cable models and accounts for neuronal AP velocity as well as introducing signal attenuation and transient delays associated with internodal demyelination. This model could aide as a predictive tool for the diagnosis and analysis of axonal signal integrity associated with demyelination pathology. Possible applications could include functional stimulation control methodologies for axon bundles that may exhibit signal fidelity issues associated with demyelination. It is further proposed that this model may serve as an instructive tool for further development and incorporation of other axon dynamic behaviors such as: relative refractory periods of AP generation, NR AP recovery mechanisms and responses to varied current stimulus input. / by George Jason Morales. / Thesis (Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

Wireless sensor networks (WSNs) provide rapid, untethered access to information, eliminating the barriers of distance, time, and location for many applications in national security, civilian search and rescue operations, surveillance, border monitoring, and many more. Sensor nodes are resource constraint in terms of power, bandwidth, memory, and computing capabilities. Sensor nodes are typically battery powered and depending on the application, it may be impractical or even impossible to recharge them. Thus, it is important to develop mechanisms for WSN which are energy efficient, in order to reduce the energy consumption in the network. Energy efficient algorithms result in an increased network lifetime. Data gathering is an important operation in WSNs, dealing with collecting sensed data or event reporting in a timely and efficient way. There are various scenarios that have to be carefully addressed. In this dissertation we propose energy efficient algorithms for data gathering. We propose a novel event-based clustering mechanism, and propose several efficient data gathering algorithms for mobile sink WSNs and for spatio-temporal events. Border surveillance is an important application of WSNs. Typical border surveillance applications aim to detect intruders attempting to enter or exit the border of a certain region. Deploying a set of sensor nodes on a region of interest where sensors form barriers for intruders is often referred to as the barrier coverage problem. In this dissertation we propose some novel mechanisms for increasing the percentage of events detected successfully. More specifically, we propose an adaptive sensor rotation mechanism, which allow sensors to decide their orientation angle adaptively, based on the location of the incoming events. In addition, we propose an Unmanned Aerial Vehicle UAV aided mechanism, where an UAV is used to cover gaps dynamically, resulting in an increased quality of the surveillance. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

The quantitative assessment of lymph node size plays an important role in treatment of diseases like cancer. In current clinical practice, lymph nodes are analyzed manually based on very rough measures of long and/or short axis length, which is error prone. In this paper we present a graph-based lymph node segmentation method to enable the computer-aided three-dimensional (3D) assessment of lymph node size. Our method has been validated on 111 cases of enlarged lymph nodes imaged with X-ray computed tomography (CT). For unsigned surface positioning error, Hausdorff distance and Dice coefficient, the mean was around 0.5 mm, under 3.26 mm and above 0.77 respectively. On average, 5.3 seconds were required by our algorithm for the segmentation of a lymph node.

There has been growing interest in the Mobile WSN applications where mobility is the fundamental characteristic of the sensor nodes. Mobility poses many challenges to the routing protocols used in such applications. In this thesis we evaluate the performance of Collection Tree Protocol as applied in mobile WSN scenarios. The simulation study shows CTP performs poorly in mobile scenario because of the frequent tree re-generation resulting from node movements. We compare Collection Tree Protocol with reactive ad hoc network routing protocols. The simulation results show that collection tree protocol performs better than reactive MANET protocols in terms of data delivery ratio and control overhead under low traffic rates. The end-to-end delay obtained in case of reactive protocols is also higher compared to that obtained when using CTP, which is due to their route discovery process. This thesis presents an improved data collection protocol Fixed Node Aided CTP based on the analysis of CTP. The protocol introduces the concept of fixed aided routing into CTP. It is shown that our enhanced CTP outperforms CTP in terms of data delivery ratio and control overhead chosen as performance metrics. / UOIT

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This thesis provides design approaches for waveguide filter with prescribed transmission zeros. The emphasis is on a new class of filter, developed in recent years by utilizing non-resonating nodes (NRNs). First, a novel circuit model of the coupling irises of waveguide filters is developed in order to aid the design of waveguide filters with NRNs for relatively wide band applications. Also, analytical solutions of the circuit parameters are presented and verified by experimental design. Secondly, based on this new circuit model, a systematic approach for the design of filters with NRNs is developed and illustrated with two filters. The first has intermediate fractional bandwidth of 3.5%; Good results are obtained without performing global optimization. The second has a relatively wide fractional bandwidth of 8.33% and good results are achieved with very limited global optimization. The results are verified by EM simulations. Furthermore, for choosing an empty waveguide to realize the NRNs, some novel criteria are proposed to improve the spurious free window of the filter.

This thesis provides design approaches for waveguide filter with prescribed transmission zeros. The emphasis is on a new class of filter, developed in recent years by utilizing non-resonating nodes (NRNs). First, a novel circuit model of the coupling irises of waveguide filters is developed in order to aid the design of waveguide filters with NRNs for relatively wide band applications. Also, analytical solutions of the circuit parameters are presented and verified by experimental design. Secondly, based on this new circuit model, a systematic approach for the design of filters with NRNs is developed and illustrated with two filters. The first has intermediate fractional bandwidth of 3.5%; Good results are obtained without performing global optimization. The second has a relatively wide fractional bandwidth of 8.33% and good results are achieved with very limited global optimization. The results are verified by EM simulations. Furthermore, for choosing an empty waveguide to realize the NRNs, some novel criteria are proposed to improve the spurious free window of the filter.

Staging is critical in the management of cancer. Sentinel lymph node (SLN) biopsy is one method used in the assessment of cancer spread. SLN procedures are standard practice in the management of some cancers although; these procedures have only recently been developed and refined. SLN procedures are commonly used in the management of melanomas and breast cancers in patients with no evidence of metastatic disease on clinical exam. SLN procedures include detection, localization, and assessment of SLNs. The detection/localization components vary in technique and rates of success. The procedures with the least number of detection/localization techniques generally include the use of blue dye or the use of a radiotracer with intraoperative gamma counting. The most complex procedures involve the use of blue dye, the use of a radiotracer with preoperative gamma imaging and preoperative gamma counting, intraoperative gamma counting, or some combination of these techniques. The ideal procedure for SLN would include all the listed techniques however; all facilities do not incorporate the most complete procedure, for different reasons. An investigation using a small FOV (5 in x 5 in) gamma camera intraoperatively for SLN procedures in melanoma and breast cancer patients was performed. A smaller FOV camera is capable of obtaining some of the same information as a conventional gamma camera. It is possible that centers, which do not or are not able to take advantage of preoperative imaging, may find the use of a smaller FOV gamma camera in the operating room useful. The investigation consisted of a total of 41 patients; it was split into two studies, Study 1: melanoma and study 2: breast cancer. The melanoma study found the added use of a smaller FOV camera under the parameters of this study to be minimal. Study 2 was broken into two branches; branch 1: camera/probe/dye and branch 2: probe/dye, for a comparison study. Comparing the two branches did not show the smaller FOV camera to reduce the time spent in the operating room versus using the probe and blue dye.

Multicasting in mobile ad hoc networks (MANETs) is an efficient method for group communications that has received considerable attention. However, developing a scalable, robust and efficient multicast method in MANETs is difficult owing to group membership management and the ability to maintain a multicast structure over a dynamic topology. This work presents a novel Robust Mesh-based Multicast Protocol (RMMP) that integrates the advantages of tree-based and mesh-based multicast protocols and reduces data recovery time when paths break. The proposed RMMP is performed in two ways. One is to construct a multicast structure using a binary tree, and the other is to provide a second-route discovery scheme. The former distributes transmission averagely among member nodes, and the latter reduces the number of articulation nodes to eliminate loss of data packets. Simulation results demonstrate that the RMMP is suitable for heavy traffic loads, and achieves a high delivery ratio. Furthermore, the RMMP is robust in recovering data transmission when paths break.