Bachelor of Science (BS), Ohio University, 2024, Astrophysics

Through a collaboration with the Dark Energy Spectroscopic Instrument (DESI), this thesis utilizes the DESI N-body simulation mock galaxies to perform statistical analyses over the data. Through this analysis, best-fit cosmological parameters are determined. The processes followed within this thesis paper outline the typical DESI analysis process when performing parameter estimation.

Committee: Hee-Jong Seo (Advisor); David Drabold (Advisor) Subjects: Astrophysics

DMA, University of Cincinnati, 2014, College-Conservatory of Music: Flute

Recent innovations by the Garner Headjoint Company in machine standardizing the making of flute headjoints has allowed us to reopen a seemingly closed discussion into the apparent differences in the power spectrum (strengths of each harmonic in the sound) produced by flutes made of different materials. Because of their standardized geometry, we can be reasonably sure that differences in power spectrum will be due to the variation in metal. Previous studies have implied that the physical composition of the flute is irrelevant to the sonic output. However, in this study, we will approach this problem by eliminating as many variables as possible besides the metals, including replacing the human flutist with an angularly accurate flute machine that plays the headjoints using a source of high purity compressed nitrogen funneled through a copper tube formed into the shape of a flute embouchure. Data acquisition was performed in a mostly anechoic chamber normally used to test the acoustics of jet engines by an array of thirteen microphones. From this, we produced unique physical portraits for six Garner headjoints sounded alone and fitted to silver Yamaha #YFL-587HCT #548, and 14K gold Yamaha YFL-997 HCT # 977A C338. While we were unable to find definite patterns explaining the power spectra we observe, this study represents a first step towards a more complete understanding of the precise effect of the materials used on the sound produced.

Committee: Bradley Garner D.M.A. (Committee Chair); Steven Cahn Ph.D. (Committee Member); Howard Everett Jackson Ph.D. (Committee Member) Subjects: Acoustics

PhD, University of Cincinnati, 2008, Medicine : Biostatistics (Environmental Health)

Allele frequency distribution (AFD) is the summarized distribution of allele frequencies of genetic loci in the studied population. AFD contains important information of population demographic history and plays a crucial in the efficient conduct of genetic association studies. Unlike the allele frequency spectrum (AFS), which is a sample level concept and has received much attention, few studies have been examined AFD due to the limitation of empirical data and computational tools. In this dissertation, we investigated AFD and its related problems relevant to genome-wide association (GWA) studies. First, we established an empirical method for estimating AFD based on observable AFS data. The method is proved to be effective and efficient. Based on data from the ‘Program for Genomic Association' (PGA) project and HapMap ENCODE project, we estimated AFD for European and African populations to be used for further analysis. We next brought up an AFD-like complex disease model which is the different from the long-debated ‘Common disease common variant” (CDCV) and “Common disease rare variant” (CDRV) model. This model is theoretically reasonable and it is compatible with observable results from human Genome-wide association (GWA) studies. Finally, we compared statistical power for common frequentist's test methods and Bayesian methods in GWA studies using the simulation strategy on our AFD and complex disease model. To avoid complicated multiple testing problem, instead of traditional power, we used ‘Rank Power' which is based on the probability of true alternative hypotheses given first N ranked hypotheses are declared to be significant. The results showed that current test methods share the similar power and the improvement of Bayesian methods in GWA studies is marginal. Results of this study further augment the analytical principles and methods involved in complex disease genetic studies and in the development of efficient designs and providing statistical solutions for (open full item for complete abstract)

Committee: Ranjan Deka PhD (Committee Chair); Ranajit Chakraborty PhD (Committee Member); Ge Zhang PhD (Committee Member); Marepalli Rao PhD (Committee Member) Subjects: Biostatistics

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

In this research, a DS-CDMA system with QPSK modulation and multiuser interference is analyzed and simulated. We investigate the BER performance for disparate data and chip rates on the I- and Q- channels for synchronous and asynchronous transmission using both orthogonal and random codes. Comparisons are made concerning the performance of the system in AWGN and Rayleigh fading channels. Power spectra for various cases are analyzed and the results show that we obtain moderate spectrum shaping and reduction in side lobes for some parameter sets. This thesis shows through using theoretical analysis and computer simulations that synchronous and asynchronous transmissions with random codes have similar performance. Our results also show that the BER is a function of the number of interfering users and processing gain, and that our disparate chip and data rate scheme presents another effective option for multi-rate transmission.

Committee: David Matolak (Advisor) Subjects:

Master of Sciences (Engineering), Case Western Reserve University, 2010, Biomedical Engineering

Study of recorded data has demonstrated that the brain exhibits gross dynamics with key spectral properties; namely that the dynamics consist of the superposition of background pink noise (P ∝ f−α) and a number of specific frequency bands. These dynamics emerge from the attributes of individual neurons, as well as manner in which those neurons are connected into a network. This work presents a novel method to reconstruct families of networks from observed dynamics given only the channel-averaged power spectrum of the dynamics and a single global constraint on network architecture. This method demonstrates that alterations in the power spectrum as a result of disease lead to observable changes in network architecture which this method is able to distinguish.

Committee: Roberto F. Galán PhD (Advisor); Kenneth J. Gustafson PhD (Committee Chair); Robert F. Kirsch PhD (Committee Member); Cameron C. McIntyre PhD (Committee Member); Dawn M. Taylor PhD (Committee Co-Chair) Subjects: Biomedical Research; Engineering; Mathematics; Neurology

Doctor of Philosophy, Case Western Reserve University, 2008, Mechanical Engineering

The scope of this dissertation is to develop and apply a non-intrusive molecular Rayleigh scattering diagnostic that is capable of providing time-resolved simultaneous measurements of gas temperature, velocity, and density in unseeded turbulent flows at sampling rates up to 32 kHz. Molecular Rayleigh scattering is elastic light scattering from molecules; the spectrum of Rayleigh scattered light contains information about the gas temperature and velocity of the flow. Additionally, the scattered signal is directly proportional to the molecular number density. These characteristics are utilized in the development of the measurement technique. This dissertation results in the following: 1. Development of a point-based Rayleigh scattering measurement system that provides time-resolved simultaneous measurement of temperature, velocity, and density at sampling rates up to 32 kHz. 2. Numerical modeling of the light scattering and detection process to evaluate uncertainty levels and capabilities of the measurement technique. 3. Validation of the developed measurement system in benchmark flow experiments in which velocity and temperature fluctuations were decoupled and independently forced at various amplitudes and frequencies. 4. Demonstration of simultaneous measurement of all three quantities in an electrically-heated free jet facility at NASA Glenn Research Center. 5. Comparison of Rayleigh scattering measurements in all experiment phases with thermal anemometry measurements. The experimental measurements are presented in terms of first-order time-series results that are measured directly by the technique, and second-order statistics, such as power spectral density and rms fluctuations, which are calculated from the direct time-resolved quasi-instantaneous measurements. Temperature fluctuation results are compared with constant current anemometry measurements and velocity fluctuation results are compared with constant temperature anemometry measurements. Experiments were (open full item for complete abstract)

Committee: Chih-Jen Sung (Advisor) Subjects: Engineering, Mechanical