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No description available.

No description available.

Pulse responses are not suitable for evaluating H(z) frequency responses that include digital errors. Digital error effects, however, are conveniently included in H(z) frequency response calculations based on the step response. A non-real time algorithm for computing the frequency response of a real time digital filters based on the filter step response is developed and verified through an example.

The hardware available for digital signal processing is evaluated. The elements required for implementation of digital signal processing applications are identified. These elements--memories, ALUs and multipliers -- are analyzed. Then the operation of parts which make up a range of possible solutions are evaluated. Thus, the graduating engineer is aided in making a transition from the theoretical to the practical world.

The TMS320 single-chip digital signal processor, produced by Texas Instruments, shows promise for a long life-cycle not only because it fills a technical need in the digital signal processing field; but because it also represents an excellent early design. Furthermore, Texas Instruments has provided thorough software and development support. However, this chip was not designed to support digital signal processing applications which require multiple-precision operations. In this paper, algorithms were developed and expressed in macros that provide the capability of modeling systems requiring multiple-precision operations. Finally, a performance envelope showing the system complexity versus sampling bandwidth limitations is provided to show the capability of the TMS320 in digital signal processing applications requiring multiple-precision.

Many have been searching for and contemplating the origins of syphilis. By understanding its emergence as a human pathogen we will be better able to elucidate its evolution through time and space as well as shed light on its current state. Ancient DNA techniques used to isolate Treponema pallidum subspecies pallidum DNA from archaeological human specimens provides direct evidence of its existence in the past. To date, only Kolman et al. (1999) have been successful in this endeavour. Along with this protocol, two other published protocols and novel allele specific techniques this thesis aims to add new cases of venereal syphilis identification from historic human remains. To accomplish this, sixteen skeletal samples from different time periods and geographic locations were collected for this project. Of importance are those dating from the Civil War time period from the United States as medical documents state these individuals suffered and/or died from the complications of syphilis. Samples from the United Kingdom are also critical to this analysis as they have confirmed pre-Columbian dates. Along with attempts to isolate bacterial DNA, endogenous DNA (mitochondrial and amelogenin) is analyzed to provide an idea of the different levels of molecular preservation. General preservation as well as the identification of syphilis are also performed using microscopic techniques. By using a tiered approach (macroscopic to microscopic to molecular), a better idea of both preservation and disease presence can be ascertained. Results indicate that although syphilis could be identified at both the macroscopic and microscopic levels for some individuals and endogenous DNA was present, treponemal DNA failed to amplify. Many different reasons are suggested, for example poor conservation methods, misdiagnosis and diagenesis, but the most important possibility is the lack of bacterial DNA in bone at later stages of syphilis which was confirmed using the rabbit model. As a result, the present techniques may not be conducive for treponemal DNA isolation from ancient human remains. / Thesis / Doctor of Philosophy (PhD)

This dissertation examines brain lateralization and interhemispheric asymmetry patterns found in youths with Attention-Deficit / Hyperactivity Disorder (ADHD). Prior research groups have found mixed findings with respect to left and right hemisphere alterations from ADHD subjects using structural magnetic resonance imaging. In these investigations, we propose the use of Asymmetry Index (AI), a subject-specific metric that quantifies the extent of brain asymmetry and allows each subject to serve as their own control, thus reducing variability when pooling across different sites. We compare AI metric with laterality across volumetric, surface area, thickness, morphology, and white matter measures in order to characterize the ADHD brain over the course of neurodevelopment, psychotropic therapy, and behavioral presentations. Linear mixed effects models were characterized to account for individual differences and maturation. We reproduce the findings across several regional and international data consortiums that contain both cross-sectional and longitudinal ADHD neuroimaging data. Structural asymmetry group differences were more significant than lateralized comparisons across a number of volumetric and white matter measures, confirming asymmetry is robust at detecting differences between healthy controls and ADHD brains. However, the effects of medication and behavioral phenotypes failed to reproduce significant alterations across symmetry measures. We discuss these implications in light of recent evidence of possible neuroprotective features of ADHD. Future work may investigate the extent to which these brain asymmetry differences are causal or compensatory. Although structural AI is unlikely to provide a useful biomarker for ADHD, a deeper understanding of these asymmetry patterns could lead to better profiling of the clinical diagnostics and to personalized treatments.

We present 197 planet candidates discovered using data from the first year of the NASA K2 mission (Campaigns 0-4), along with the results of an intensive program of photometric analyses, stellar spectroscopy, high-resolution imaging, and statistical validation. We distill these candidates into sets of 104 validated planets (57 in multi-planet systems), 30 false positives, and 63 remaining candidates. Our validated systems span a range of properties, with median values of R-P = 2.3 R-circle plus, P = 8.6 days, T-eff = 5300 K, and Kp = 12.7 mag. Stellar spectroscopy provides precise stellar and planetary parameters for most of these systems. We show that K2 has increased by 30% the number of small planets known to orbit moderately bright stars (1-4 R-circle plus, Kp = 9-13. mag). Of particular interest are 76 planets smaller than 2 R-circle plus, 15 orbiting stars brighter than Kp = 11.5. mag, 5 receiving Earth-like irradiation levels, and several multi-planet systems-including 4 planets orbiting the M dwarf K2-72 near mean-motion resonances. By quantifying the likelihood that each candidate is a planet we demonstrate that our candidate sample has an overall false positive rate of 15%-30%, with rates substantially lower for small candidates (<2 R-circle plus) and larger for candidates with radii >8 R-circle plus and/or with P < 3 days. Extrapolation of the current planetary yield suggests that K2 will discover between 500 and 1000 planets in its planned four-year mission, assuming sufficient follow-up resources are available. Efficient observing and analysis, together with an organized and coherent follow-up strategy, are essential for maximizing the efficacy of planet-validation efforts for K2, TESS, and future large-scale surveys.

We present a catalog of 11 multiplanet systems from Campaigns 1 and 2 of the K2 mission. We report the sizes and orbits of 26 planets split between seven two-planet systems and four three-planet systems. These planets stem from a systematic search of the K2 photometry for all dwarf stars observed by K2 in these fields. We precisely characterized the host stars with adaptive optics imaging and analysis of high-resolution optical spectra from Keck/HIRES and medium-resolution spectra from IRTF/SpeX. We confirm two planet candidates by mass detection and validate the remaining 24 candidates to >99% confidence. Thirteen planets were previously validated or confirmed by other studies, and 24 were previously identified as planet candidates. The planets are mostly smaller than Neptune (21/26 planets), as in the Kepler mission, and all have short periods (P < 50 days) due to the duration of the K2 photometry. The host stars are relatively bright (most have Kp < 12.5 mag) and are amenable to follow-up characterization. For K2-38, we measured precise radial velocities using Keck/HIRES and provide initial estimates of the planet masses. K2-38b is a short-period super-Earth with a radius of 1.55 +/- 0.16 R-circle plus, a mass of 12.0 +/- 2.9M(circle plus), and a high density consistent with an iron-rich composition. The outer planet K2-38c is a lower-density sub-Neptune-size planet with a radius of 2.42 +/- 0.29 R-circle plus and a mass of 9.9 +/- 4.6M(circle plus) that likely has a substantial envelope. This new planet sample demonstrates the capability of K2 to discover numerous planetary systems around bright stars.