Doctor of Philosophy, The Ohio State University, 2022, Human Ecology: Human Development and Family Science

According to the American Society of Metabolic and Bariatric Surgery (ASMBS) clinical practice guidelines, all patients seeking bariatric surgery are required to have a preoperative psychological evaluation. The purpose of the psychological evaluation is to assess current and untreated mental health diagnoses, disordered eating, substance use and psychosocial history prior to surgery (Mechanick et al., 2020). However, there is no clear guidance on how these areas should be assessed within the evaluation. These guidelines also do not provide guidance on how providers should assess family/relational contexts that may also influence the patients' ability to modify and maintain health behaviors. This is critical information that is needed to establish consistency of the preoperative psychological evaluation process between centers to ensure equity for bariatric patients in the evaluation process between centers. This current dissertation presents the results of three studies which investigated associations between psychological evaluation pass/delay rates, demographics, current diagnoses (mental health, disordered eating, substance use), postoperative outcomes, impairment/no impairment on that piloted relational screener, and whether a patient completed the behavioral health consultation once screening as impaired. It also explored the preliminary feasibility of piloting a brief relational screener alongside the standard psychological evaluation and referral pathways. The first study provides evidence about which mental health, disordered eating, and substance use diagnoses associate with patient pass and delay rates from the bariatric surgery preoperative psychological evaluation. It also investigated reasons, recommendations, and referrals for delay and denial after the postoperative psychological evaluation. Significant associations between pass/delay rates and demographics, current mental health treatment, and having a current mental health, disordered (open full item for complete abstract)

Committee: Keeley Pratt (Advisor); Natasha Slesnick (Committee Member); Ashleigh Pona (Committee Member); Brian Focht (Committee Member); Lorraine Wallace (Committee Member) Subjects: Health Sciences; Psychotherapy; Social Psychology

Master of Science in Electrical Engineering, Cleveland State University, 2021, Washkewicz College of Engineering

In this thesis, we draw attention to the problem of cross-service attacks, that is, attacks that exploit information collected about users from one service to launch an attack on the same users on another service. With the increased deployment and use of what fundamentally are integrated-services networks, such as 4G/LTE networks and now 5G, we expect that cross-service attacks will become easier to stage and therefore more prevalent. As running example to illustrate the effectiveness and the potential impact of cross-service attacks we will use the problem of account association in 4G/LTE networks. Account association attacks aim at determining whether a target mobile phone number is associated with a particular online account. In the case of 4G/LTE, the adversary launches the account association attacks by sending SMS messages to the target phone number and analyzing patterns in traffic related to the online account. We evaluate the proposed attacks in both a local 4G/LTE testbed and a major commercial 4G/LTE network. Our extensive experiments show that the proposed attacks can successfully identify account association with close-to-zero false negative and false positive rates. Our experiments also illustrate that the proposed attacks can be launched in a way that the victim receives no indication of being under attack.

Committee: Ye Zhu (Committee Chair); Yongjain Fu (Committee Member); Sui-Tung Yau (Committee Member) Subjects: Computer Engineering; Computer Science; Electrical Engineering; Information Technology; Technology

MS, University of Cincinnati, 2020, Engineering and Applied Science: Electrical Engineering

The following thesis presents a multiuser coordinating scheme used in an indoor positioning system for first responders using the LTE Sidelink waveform on software defined radios (SDR), in order to estimate time-of-arrivals (TOA) between any two devices which are required for locations estimation using the differential Time Difference of Arrival (dTDOA) algorithm. When first responders enter a building to execute a rescue mission, they may not be aware of their surroundings inside the building which may put their lives at risk. The locations estimated from the indoor positioning system can be integrated with Building Information Modeling (BIM) layout, this reduces risk for the first responders as they will be more aware of their surroundings and helps them to carry out their rescue mission safely. The transceiver software for the SDRs was developed by using the LTE Sidelink waveform instead of commercial location services like the global positioning system (GPS) since it cannot penetrate buildings for an indoor setting, or like Wi-Fi signals which may be present inside buildings but may not be available during an emergency situation. The developed transceiver is simulated in MATLAB on one laptop computer going through six different stages of multiuser coordination scheme. For over the air tests in an actual indoor setting, the transceiver software developed on MATLAB is embedded onto software defined radios (SDR) and is tested at the Pavilion building at the University of Cincinnati. The following thesis mainly focuses on the Multi-User Coordination Scheme (MUCS) developed for the indoor positioning system. The over the air testing consists of 6 Universal Software Radio Peripheral (USRPs) SDRs at random locations, each USRP has two channels of which one is used for transmission and other for reception. The performance metrics for evaluating results from simulation and over the air results are average mean error and standard deviation of distance between the es (open full item for complete abstract)

Committee: H. Howard Fan Ph.D. (Committee Chair); Badri Vellambi Ravisankar Ph.D. (Committee Member); Xuefu Zhou Ph.D. (Committee Member) Subjects: Electrical Engineering

Doctor of Philosophy, The Ohio State University, 2020, Electrical and Computer Engineering

With the increasing demands for wireless control, infotainment communication and telematics service, modern cars are equipped with more and more radio frequency (RF) systems such as Global Navigation Satellite System (GNSS), Satellite Digital Audio Radio Service (SDARS), Cellular, Vehicle-to-Everything (V2X), and Wireless Local Area Network (WLAN), for navigation, communication, and entrainment needs. Not only does the number of frequency bands increase, but also the operating frequency goes higher and higher for more bandwidths. However, operating at a higher frequency is accompanied by faster fading issue which can be mitigated via the utilization of diversity reception from multiple antennas with different pattern coverages, polarizations, and spatial locations. However, packing many antennas into a compact low-profile volume as demanded by automobile manufacturers is no easy task because 1) the dimensions of antennas are typically comparable to a quarter to one half of operating wavelengths, and 2) strong coupling and blockage effects occur when other antennas are in proximity (less than a quarter of wavelengths). In addition, the most critical practical requirements of the next generation automobile antennas are low cost, easy installation, low profile, small footprint, covers from 0.7 GHz to 6 GHz, and support up to 4 channels MIMO radios. Unlike the conventional approach of using different antennas for LTE cellular, WLAN, and V2X different systems, Our proposed a compact ultra-wide bandwidth (UWB) universal antenna system reduced the total number of antennas, and thus overall antenna volume, by combing LTE, WLAN, and V2X operations into the same antenna body due to their similarity in pattern coverage and polarization requirements. Note that this is actually very challenging since the antenna needs to work over a very wide bandwidth to support 4G LTE (700 MHz-960 MHz, 1700MHz-2100MHz, 2500MHz-2700MHz, 3400MHz-3700MHz), C-Band of 5G sub6 (3300MHz-5000 (open full item for complete abstract)

Committee: Chi-Chih Chen (Advisor); Nima Ghalichechian (Committee Member); Fernando Teixeira (Committee Member); C.K. Shum (Committee Member) Subjects: Electrical Engineering; Electromagnetics

MS, University of Cincinnati, 2019, Engineering and Applied Science: Electrical Engineering

The following research presents seven line-of-sight (LOS) time-of-arrival (TOA) estimation and multipath mitigation techniques for an ad hoc positioning system built upon new Long-Term-Evolution (LTE) Sidelink, or proximity service (ProSe), waveforms. The positioning system allows emergency first responders to receive accurate location information within indoor environments. Conventional services, such as the Global Positioning System (GPS), are not strong enough to penetrate buildings. Therefore, they are unavailable indoors. The LTE Sidelink waveforms allow communication devices within close proximity to communicate with one another, relieving the need to be connected to a larger network or infrastructure. Signals reflect more frequently indoors, bouncing off walls and objects. This results in severe multipath distortion and, therefore, potentially erroneous TOA measurements. The techniques, categorized as traditional or neural-network-based, were researched and developed to combat this multipath error. To evaluate each method, LTE Sidelink waveforms were generated then passed through a simulated noisy and multipath-laden channel. The techniques processed the channel outputs. The average difference between the true and estimated TOA over 500 independent tests determined performance. Simulations covered several LTE and reference signal configurations. Much of the previous work reviewed assumes multipath signal components have lower power than the LOS component. This is not always the case indoors. For an LTE bandwidth (BW) of 5 MHz, the LTE configuration for which the positioning system is designed, neural network methods outperform traditional techniques. Of the traditional methods, Projection onto Convex Sets or Modified Conventional Correlation perform best, with TOA estimation error decreasing as reference signal BW increases.

Committee: H. Howard Fan Ph.D. (Committee Chair); Badri Narayanan Vellambi Ravisankar (Committee Member); Xuefu Zhou Ph.D. (Committee Member) Subjects: Electrical Engineering

Doctor of Philosophy, The Ohio State University, 2017, Electrical and Computer Engineering

Increasing demand for supporting more wireless services with higher performance and reliability within the frequency bands that are most conducive to operating cost-effective cellular and mobile broadband is aggravating current electromagnetic spectrum congestion. This situation motivates technology and management innovation to increase the efficiency of spectral use. If primary-secondary spectrum sharing can be shown possible without compromising (or while even improving) performance in an existing application, opportunities for efficiency may be realizable by making the freed spectrum available for commercial use. While both active and passive sensing systems are vitally important for many public good applications, opportunities for increasing the efficiency of spectrum use can be shown to exist for both systems. This dissertation explores methods and technologies for remote sensing systems that enhance spectral efficiency and enable dynamic spectrum access both within and outside traditionally allocated bands.

Committee: Joel Johnson (Advisor); Emre Ertin (Committee Member); Graeme Smith (Committee Member) Subjects: Electrical Engineering; Electromagnetics

MS, University of Cincinnati, 2015, Engineering and Applied Science: Computer Science

E-SCALE, Energy-efficient Scalable sensor Coverage with cell-phone Apps using LTE, is a newly adopted approach to provide large scale sensor coverage using cell phones and cellular network infrastructure. The focus of this thesis is to propose the idea of E-SCALE, extend it through simulations to determine how E-SCALE and its traffic can impact the key performance indices of the backbone network, i.e., LTE in this case. E-SCALE addresses the problem of providing occasional sensor coverage in a public area that occasionally hosts a large number of people. Since, investing for permanent sensor network based surveillance infrastructure in such places involves fairly large amount of money. Thus, E-SCALE is conceived for providing on-the-fly safety surveillance for occasional crowd. In our simulation we have taken LTE as the backbone infrastructure essential for E-SCALE. Our simulation results shows that a large area occupied by a crowd can be taken under environmental and safety surveillance monitoring by simply using the cell phones' sensors of the people gathered over the concerned area. E-SCALE can also take care of the battery power saving of the audience's cell phones to make it an energy-efficient technique. Smart phones are mostly equipped with hi-end sensor systems like temperature sensors, toxic-gas-sensors and likewise many more to be expected in near future. Hence, without any requirement of explicit sensors deployment for say, fire-safety, air-pollution, toxic gas detection, etc., a large area with gathering of people can be monitored continually, effectively and that's too in an energy efficient way.This thesis reports detail simulation results how this sensor data traffic could affect the LTE network performance. Another effort is made to reduce the battery power consumption of the user equipment so that the guests can freely use applications other than E-SCALE during the gatherings and the user equipment do not suffer from drainage of high battery power. (open full item for complete abstract)

Committee: Dharma Agrawal D.Sc. (Committee Chair); Raj Bhatnagar Ph.D. (Committee Member); Chia Han Ph.D. (Committee Member) Subjects: Computer Science