Electronic Theses and DissertationsSelected theses and dissertations from Baylor University departments that offer graduate degrees.https://hdl.handle.net/2104/92212019-03-21T00:16:04Z2019-03-21T00:16:04ZCorrelation of Skin Friction and Convective Heat Transfer on Surfaces with Realistic Roughness Variationshttps://hdl.handle.net/2104/105332019-02-13T09:04:26ZCorrelation of Skin Friction and Convective Heat Transfer on Surfaces with Realistic Roughness Variations
Kinematic effects of mechanical horse simulated hippotherapy.https://hdl.handle.net/2104/105262019-02-02T09:05:27Z2018-07-10T00:00:00ZKinematic effects of mechanical horse simulated hippotherapy.
Hippotherapy is the use of horseback riding as a form of therapy for a variety of disabilities such as cerebral palsy, multiple sclerosis, and autism. It is also known that hippotherapy can be beneficial for stroke patients and for people suffering lower back pain. Studies have shown that horses' walking patterns exhibit similarities to those of normal human gait, and can have positive effects on people with disabilities or injuries. The aim of this study was to measure and analyze the human body motion responses produced by non-disabled riders of a mechanical horse-riding simulator (MHS) that was developed at Baylor University. In addition, pre and post-test measures were analyzed to compare the after-effects of riding. During riding, the healthy riders' trunk motions tracked closely with the mechanical horse motion in all three anatomical planes. Balance tests showed that the riders, on average, decreased sway in the frontal and sagittal planes after riding, but increased yaw in the transverse plane. The results that the MHS can produce similar kinematic effects to that of a horse should be of interest for the purpose of broadening accessibility to the potential benefits of equine-like motion therapy.
2018-07-10T00:00:00ZThe Elkins Hypnotizability Scale : validity, reliability, factor structure, and acceptability within a clinical sample.https://hdl.handle.net/2104/105252019-02-02T09:05:22Z2018-07-18T00:00:00ZThe Elkins Hypnotizability Scale : validity, reliability, factor structure, and acceptability within a clinical sample.
The current dissertation aimed to explore the reliability, validity, and factor structure of the Elkins Hypnotizability Scale (EHS) in a clinical sample of 173 post-menopausal women (Study 1). Study 1 included pre-existing data from a randomized-controlled trial on clinical hypnosis in the treatment of post-menopausal hot flashes. As hypothesized, the EHS demonstrated adequate reliability (α = .797) and high convergent validity with the current gold standard measure of hypnotizability, the Stanford Hypnotic Susceptibility Scale, Form C (SHSS: C) (ρ = .894). Results provided evidence that the EHS (M = 8.580) and SHSS: C (M = 8.415) were perceived to be equally pleasant. Additionally, Study 1 results indicated a high correlation between the SHSS: C and a shortened clinical version of the EHS (EHS: C) (ρ = .849), and a significant positive correlation between participants’ levels of dissociation on the EHS imagery task and total EHS score (ρ = .740). Study 1 confirmatory factor analysis results did not support the proposed four-factor structure of the EHS or SHSS: C. The results instead indicated that both the EHS (χ2 (9) = 8.412, p = .4932; CFI = 1.00; RMSEA < .001) and SHSS: C (χ2 (54) = 80.778, p = .0106; CFI = .971; RMSEA = .054) reflect a unidimensional structure in which the individual items on the scales are indicators for a general hypnotizability latent variable. Study 2 examined whether the model fit in Study 1 held in a multi-group sample consisting of the clinical sample in Study 1 and a collegiate sample of 225 Baylor University students. As predicted, measurement invariance test results suggested that the EHS (χ2 (18) = 38.575, p = .003, CFI = .986, RMSEA = .076) and the SHSS: C (χ2 (130) = 180.400, p = .002, CFI = .983, RMSEA = .044) demonstrate the same parsimonious single-factor structure, as demonstrated in Study 1. More specifically, the EHS reflected configural invariance across samples and the SHSS: C reflected strict invariance across samples. Implications for use of the EHS and EHS: C in clinical and research settings, as well as study limitations, and directions for future research were explored.
2018-07-18T00:00:00ZMoment representations of exceptional orthogonal polynomials.https://hdl.handle.net/2104/105242019-02-02T09:05:20Z2018-07-12T00:00:00ZMoment representations of exceptional orthogonal polynomials.
Exceptional orthogonal polynomials (XOPs) can be viewed as an extension of their classical orthogonal polynomial counterparts. They exclude polynomials of a certain order(s) from being eigenfunctions for their corresponding exceptional differential operator, while surprisingly still forming a complete set of eigenpolynomials for that operator. In Chapters Two and Three, we examine the (so-called) Type I $X_1$-Laguerre polynomial sequence, where the constant polynomial is omitted, and the Type I $X_2$-Laguerre polynomial sequence, where both the constant and linear polynomials are omitted. In the literature, one method presented for obtaining XOPs has been to apply Gram--Schmidt orthogonalization to a so-called ``flag". For our purposes, a flag is an infinite set of mutually linearly independent vectors which span the space of a particular XOP. Here, we use a known flag to generate the $X_1$ sequence, and find a new flag to generate the $X_2$ sequence. The particular canonical flag we pick keeps both the determinantal representation and the moment recursion manageable. We also develop a flag that could be extended to the general $X_m$ exceptional Laguerre polynomials. We derive two representations for the $X_1$ polynomials in terms of moments by using determinants. The first representation in terms of the canonical moments is rather cumbersome. We introduce adjusted moments and find a second, more elegant formula. We deduce a recursion formula for the moments and the adjusted ones. The adjusted moments are also expressed via a generating function. These representations are then extended to the $X_2$ case. We explore various complicating factors that arise in moving on to XOPs of a higher co-dimension.
Finally, by employing the Darboux transform, these representations in terms of adjusted moments are then generalized to any of the $X_1$ exceptional orthogonal polynomials, regardless of the underlying family (Jacobi or Laguerre). We include a recursion formula for the adjusted moments, and provide the initial adjusted moments for each system. Throughout we relate to the various examples of $X_1$ exceptional orthogonal polynomials, but we especially focus on and provide complete proofs for the Jacobi and the Type III Laguerre cases, as they are less prevalent in literature.
2018-07-12T00:00:00Z