Doctor of Philosophy, The Ohio State University, 2007, Food, Agricultural, and Biological Engineering

Advancements in sensing and monitoring of air quality parameters within confined animal feeding operations have been realized through the application of embedded systems and advanced networking. The development of an embedded vibration sensor to detect the presence of ventilation fan activity provided researchers with an improved method to monitor ventilation from high capacity CAFO facilities. Experiments revealed over estimation errors common to the majority of passive ventilation sensors. Analysis of ventilation sensor systems resulted in proposed limits to overall measurement error by minimizing the modulus of fan on-time and sampling time. Controller Area Networks were found to be a viable means to link multiple analog and digital sensors through a multi-master based embedded network. It was found that signal attenuation was significant as bus lengths increased to a maximum of 600 meters. This attenuation was counteracted by reducing the baud rate of the communication and allowing for longer bit times. Signal reflection of the individual bits was another major factor of transmission error caused by the mismatch of impedance between the signal wire and the termination resistor. Wireless sensor networks were also evaluated for their potential to act as the data communication network within a multi-point sampling system inside a CAFO. Results from experimental path loss studies found many factors including antenna orientation, enclosure thickness, free space, antenna height, animal cages, and concrete floor separations to all be statistically relevant factors in determining the overall system path loss. It was further found that linear separation within an aisle and number of cage separations provided the highest levels of signal attenuation. A model was developed to predict the path loss at any point within a poultry layer facility based on the aisle and cage separation terms. The model was able to predict 86% of the system variability and was able to produce an (open full item for complete abstract)

Committee: Lingying Zhao (Advisor) Subjects: Engineering, Agricultural

Master of Science (MS), Ohio University, 1983, Electrical Engineering & Computer Science (Engineering and Technology)

Evaluation of a terrain-sensitive, propagation path loss model based upon the geometrical theory of diffraction, modified for finite conductivity and local surface roughness.

Committee: C Kent (Advisor) Subjects:

Master of Science (MS), Ohio University, 2006, Electrical Engineering & Computer Science (Engineering and Technology)

This work is a collection of new measurement results for indoor channel characteristics in two unlicensed bands. Part of the work is also an extension of another Ohio University student's MS Thesis [3]. The effects of human movement on the propagation characteristics were not taken into consideration in that work, and that is one of our contributions here. The measurement and characterization of propagation path loss vs. distance on single and multiple floors with and without the movement of people in an indoor environment were performed. It has been observed that the propagation within buildings is strongly influenced by specific features such as the layout of the building, construction materials, and the building type. We have used our measurements and results from a database to estimate building material composition. A widely used propagation model is one in which there is a dominant signal arriving along with many weaker signals: this gives rise to a Ricean amplitude distribution. We have computed the Rice factor from our measurements, using the moment estimation method. We have also made a first attempt to estimate the Doppler spectrum from the signal power samples due to the time variations of the scatterers.

Committee: David Matolak (Advisor) Subjects:

Master of Science (MS), Ohio University, 2004, Electrical Engineering & Computer Science (Engineering and Technology)

This thesis deals with the characterization of indoor wireless channels in the ISM bands (902-928 MHz and 2.4-2.5 GHz). This characterization encompasses estimation of propagation path loss vs. distance, magnitude of the channel transfer functions and amplitude correlation functions using propagation measurements. The thesis explains the various propagation models, their importance and the parameters used in these models to characterize indoor channels. The experiments supporting this thesis were conducted in Stocker Center, the engineering school of the university. In the first part, path loss vs. distance on various floors was measured. The results were used to determine the path loss exponent and standard deviation. The second part of the thesis addresses dispersive channel parameters and measurements of the amplitude-squared transfer functions and amplitude correlation functions. These measurements and models are a useful first-order description of the channel.

Committee: D. Matolak (Advisor) Subjects:

Doctor of Philosophy (Ph.D.), University of Dayton, 2012, Electrical Engineering

In recent years there has been growing interest in Ad-hoc and Wireless Sensor Networks (WSNs) for a variety of indoor applications. Localization information in these networks is an enabling technology and in some applications it is the parameter of primary importance. WSNs are being used in a variety of ways - from reconnaissance and detection in military to biomedical applications and a wide variety of commercial endeavors. In recent years, position-based services have become more important. Thus, recent developments in communications and RF technology have enabled system concept formulations and designs for low-cost radar systems using state-of-the-art software radio modules, which are capable of local processing and wireless communication, a reality. Such nodes are called as sensor nodes. Each sensor node is capable of only a limited amount of processing. This research focused on the modeling and implementation of distributed, mobile radar sensor networks. In particular, we worked on the problem of Position-Adaptive Direction Finding (PADF), to determine the location of a non-collaborative transmitter, possibly hidden within a structure, by using a team of cooperative intelligent sensor networks. Our purpose is to further develop and refine position-adaptive RF sensing techniques based on the measurement and estimation of RF scattering metrics. Topics planned for this entrepreneurial research project are focused on the investigation, analysis/simulation, and development of real time multi-model (i.e., complex multipath) environments scattering decompositions for PADF geometries. PADF is based on the formulation and investigation of path-loss based RF scattering metrics (i.e., estimation of distributed Path Loss Exponent, or PLE) that are measured and estimated across multiple platforms in order to enable the robotic/intelligent position-adaptation (or self-adjustment) of the location of each platform. We provide a summary of recent experimental results in localiz (open full item for complete abstract)

Committee: Raul Ordonez PHD (Committee Chair); Robert Penno PHD (Committee Member); John Loomis PHD (Committee Member); Robert Gorton PHD (Committee Member) Subjects: Electrical Engineering