PHD, Kent State University, 2022, College of Arts and Sciences / Department of Computer Science

Recently, location-based social networks, that involve both social and spatial information, have received much attention in many real-world applications such as location-based services (LBS), map utilities, business planning, and so on. User's location is one of the most important components of user context that implies extensive knowledge about an individual's interests and behavior, thereby providing researchers with opportunities to better understand users in a social structure according to not only online user behavior but also the user mobility and activities in the physical world. In this dissertation, we have an initial study of query processing over spatial-social networks and propose suitable solutions of query processing over spatial-social networks by proposing new novel queries that are Community Search (CS), Group Planning (GP), and Community Detection (CD) over the spatial-social network settings. For each proposed query over spatial-social networks, we have designed effective pruning strategies to reduce the search space by filtering false alarms, proposed effective indexing mechanisms to facilitate the query processing, and develop efficient query answering algorithms via index traversals. Extensive experiments have been conducted to evaluate the efficiency and effectiveness of our proposed queries processing approaches.

Committee: Xiang Lian (Advisor); Gokarna Sharma (Committee Member); Jay Lee (Committee Member); Omar De La Cruz Cabrera (Committee Member); Qiang Guan (Committee Member) Subjects: Computer Science

Master of Science (MS), Ohio University, 2021, Electrical Engineering (Engineering and Technology)

Over the coming decades, as the volume of space missions continues to grow and iversify, so too does the demand for methods to achieve improved position, navigation, and timing service performance in geostationary orbit and beyond. For high-altitude spacecraft to utilize GNSS navigation techniques, it is required that they must utilize signals from GNSS space vehicles from across the limb of the Earth, which severely limits the quality and quantity of measurements that can be made. The performance potential for such a spacecraft can be improved, however, by having the ability to utilize any combination of satellites visible at a given time, across all GNSS constellations. Interoperability of this kind depends primarily on the ability to resolve the differences in each system's specific time scale. This thesis proposes and develops methods to provide high-accuracy GNSS measurements from a GNSS receiver in low Earth orbit to facilitate the estimation of GNSS inter-constellation timing offsets. The Bobcat-1 CubeSat was developed to support the collection of this data, and this thesis describes the capabilities and measurement accuracy achieved by the CubeSat as well as the post-processing performed to produce precise inter- constellation timing offsets. Furthermore, a study was conducted using a simulation that was developed to evaluate the performance impacts that GNSS system time offsets impose on a user in geostationary orbit. This study produces quality of service benchmarks that are used to provide performance targets for the accuracy of the inter-constellation time offset estimates enabled by data from Bobcat-1. This thesis compares the inter-constellation timing offset estimates achieved by these methods against the Galileo-to-GPS time offset that is produced by the Galileo Control Segment and included within the navigation messages of Galileo space vehicles.

Committee: Sabrina Ugazio (Advisor); Frank Van Graas (Committee Member); Chad Mourning (Committee Member); Nathaniel Szewczyk (Committee Member) Subjects: Aerospace Engineering; Electrical Engineering

Master of Sciences (Engineering), Case Western Reserve University, 2018, EMC - Mechanical Engineering

The knowledge and understanding of the dynamic frictional response of granular geo-materials found in earthquake faults using experimental and modeling techniques has consistently proven to be the key to advancements in the research of fault mechanics. In the present study, a modified torsional Kolsky bar apparatus is adapted to investigate the frictional and microstructural behavior of confined granular rock gouge under seismically relevant normal stresses and slip velocities. Slip speeds ranging between ~ 2 m/s and 6 m/s are achieved at normal stresses ranging between ~ 50 and 125 MPa. The maximum slip distance obtained during the frictional slip is about 5 mm. Moreover, microstructural analyses of sheared gouge material is conducted using a high-resolution scanning electron microscope to reveal any possible principle slip zones as well as alterations in grain shape and size with slip and increased normal stress.

Committee: Vikas Prakash (Advisor); Ashley Griffith (Committee Member); Bo Li (Committee Member) Subjects: Mechanical Engineering

MARCH, University of Cincinnati, 2017, Design, Architecture, Art and Planning: Architecture

This paper reviews some of the earliest thoughts about the introduction of natural elements such as biology and geology into architectural design and discusses several designers' contributions, showing how they pushed the concept forward. It then explores one of the most important features of sedimentary rock formations (commonly seen around the Great Lakes area), called “cross bedding.” After some digital and physical simulations of cross bedding's irregular waving surface, the paper discusses the potential architectural applications. Last, it introduces a design proposal using cross bedding as part of the building components to design a tourist center near Watkins Glen, NY, and the Finger Lakes.

Committee: Christoph Klemmt A.A. Dipl. (Committee Chair); Elizabeth Riorden M.Arch. (Committee Member) Subjects: Architecture

Master of Science, University of Toledo, 2016, Civil Engineering

The motivation of this research originates from the hypothesis that the sinkhole occurrences in the karst areas are significantly affected by the mechanical behavior of geomaterials, chemical dissolution, hydrological transport and scenarios. The development and formation of sinkholes is strongly dominated by the geo-mechanical characteristics of soil and rock behavior complicated by the chemical interaction and hydraulic transport processes. Sinkholes formed in soils can be sudden and catastrophic in nature and involve many intricate processes which have not yet been assessed properly. This thesis presents preliminary results of an ongoing research focusing on mechanical and coupled hydro-mechanical modelling approaches, aimed to understand the diverse and intricate mechanisms behind the formation and development of cover-collapse and cover-subsidence types of sinkholes. The feasibility of the geomechanics approach of the sinkholes, understanding the critical factors and mechanisms involved in the formation of sinkholes and their deformation characteristics has been assessed using FLAC 2D. First, a parametric study was conducted in order to examine the effects of shape and size of the cavity, overburden thickness and pressure related to vertical stress and deformation. Larger sizes of the cavity and higher overburden pressures cause higher deformation at the cavity resulting in sinkhole development. Similarly, shape of the cavity is also an influential factor inducing sinkhole formation. Circular cavities are found more stable than the square and rectangular cavities. Second, the FLAC was also used to model the behavior of geomaterials around a cavity in various potential water drawdown scenarios. Deeper lowering of the water table was found to cause larger deformation. Moreover, the influence of the slow and rapid drawdown of the water is studied thoroughly, the results show that the rapid drawdown induces fast creation of sinkholes. However, slow drawdown has li (open full item for complete abstract)

Committee: Liangbo Hu (Committee Chair); Brian W. Randolph (Committee Member); Eddie Chou (Committee Member) Subjects: Civil Engineering

Master of Science, The Ohio State University, 2016, Dentistry

Purpose: To determine the relationship between toxic stress from negative social determinants of health and behavior of children at the initial dental visit. Methods: Using a 17-state sample of children 4-5 years-old, behavior ratings, using a 4-point scale, applied by trained dental professionals at initial dental visits were analyzed using bivariate and multivariate logistic regression models as well as Naive Bayes classification and chi-squared tests. Each child's behavior rating was correlated with social determinants using geographic mapping for racial/ethnic status, violence, education level, income, living conditions and other factors known to influence health. Results: Behavior ratings for 4-year-old (n=17,486) and 5-year-old (n=19,613) children were obtained for first dental visit over a five year period (2009-2013). Behavior was good (n=11,999) and not good (n=25,100). The odds ratio correlating individual socioeconomic factors to behavior showed that children with more negative behavior were more likely to experience violent crime (P=.0004), parental unemployment (P=.0002), less parental education (P=.0006), high expense on food and transportation per capita income (P=.0005), living in a more densely populated area (P=.028), non-homeowner (P=.0001), with a greater amount spend on housing per capita income (P=.0009), African-American (P=.0008), and a lower median household age (P=.0003). Children with good behavior rating were more likely to be of Latino or white ethnicity (P=.0002), come from homes owned by parents (P=.007), having a male to female ratio closer to 1:1 (P=.031), spent a greater amount on health related expenses (P=.015), and a larger average home size (P=.0002). Conclusion: This study of 37,099 4-and-5-year-old children, found poorer behavior at initial dental examination for children exposed to violence crime, parental unemployment, less parental education, high expense on food and transportation per capita income, non-homeo (open full item for complete abstract)

Committee: Paul Casamassimo (Advisor); Dennis McTigue (Advisor); Nowak Arthur (Advisor) Subjects: Dentistry

Doctor of Philosophy, The Ohio State University, 2015, Animal Sciences

Study of cell cycle activity is critical to understand development of adipose tissue, because the switch on and off of cell cycle activity is tightly related to hyperplasia and hypotrophy of the fat cells. Three cell cycle inhibitors - CCNG2, CDKN2C and PMP22, and three cell cycle activators for adipose tissue - CCNA1, CCND3 and ANAPC5, were selected as important cell cycle regulators for adipogenesis based on analyses of Gene Expression Omnibus (GEO) DataSets (GDSs) in the website of the National Center for Biotechnology Information (NCBI). The three important cell cycle inhibitors showed higher expression in fat cells than in preadipocytes and increased exprerssion during primary cell culture and development of adipose tissue in quantitative real-time PCR (qPCR) or western blotting. The results suggest that expression of these cell cycle inhibitors generally increases with the differentiation of fat cells and the growth of pig adipose tissue. In broiler chickens, expression of CCNG2, CDKN2C, CCND3 and ANAPC5 reaches a peak at post-hatch day 5 and decreases in the later stages, suggesting that day 5 may be an important time with active proliferation and differentiation of preadipocytes. The result of PCNA immunostaining suggests that proliferation activity of fat cells keeps decreasing from embryo day 15 to post-hatch day 33. The result of H&E staining suggests that fat cell size keeps increasing until post-hatch day 11. Therefore, both hypertrophic and hyperplastic growth is active before post-hatch day 5. From post-hatch day 5 to day 11, as proliferation activity decreases and most preadipocytes become differentiated, hypertrophic growth gradually becomes dominant. In the third experiment, some tissue specific secretory factors in mouse were selected based on GEO data analysis and bioinformatic tools. The tissue specific expressions of the selected genes were confirmed using semi-quantitative PCR. Secretion of five novel genes were then validated thro (open full item for complete abstract)

Committee: Michael Davis E. (Advisor); Kichoon Lee (Committee Member); Macdonald Wick (Committee Member); Harald Vaessin (Committee Member) Subjects: Animal Sciences; Animals; Bioinformatics; Biology

Doctor of Philosophy, The Ohio State University, 2014, Geography

If nations are imagined communities, how are they imagined geographically? This dissertation answers the question by investigating discourses of geographical self-awareness in South Korea. This dissertation investigates how the imagined geography of South Korea reinforces the Korean national identity through three case studies. In South Korea, the national geography is narrated as being vulnerable and at the same time as embodying the indomitable spirit of the tiger. The narrative runs through the establishment of the peace monument for Comfort Women; the construction of the Jeju naval base against commies; and the donation of foreign aid to Africa. The dissertation concludes that the imagined geography of South Korea reinforces an exclusive and defensive Korean one-ness that yearns for a place in the world.

Committee: Daniel Sui (Advisor); Darla Munroe (Advisor); Nancy Ettlinger (Committee Member); Kendra McSweeney (Committee Member) Subjects: Asian Studies; Geography

Master of Science, The Ohio State University, 2010, Computer Science and Engineering

Cable networks demand a high level of reliability as critical services are carried over them. Maintenance operations will be greatly facilitated if faults can be geographically located on the network topology. We demonstrate the application of knowledge-based techniques and a novel ontology based software framework for topology discovery and geo-localization by integrating topology data with data from GIS based systems, where these databases have incomplete, obsolete or inaccurate information. In addition to addressing this specific problem this framework may be generalized for integration of data from multiple sources with syntactic heterogeneity.

Committee: Dr. Rajiv Ramnath (Advisor); Dr. Ola Ahlqvist (Committee Member); Dr. Jay Ramanathan (Committee Member) Subjects: Computer Science