A prototype Compton scatter camera for imaging gamma rays has been built and tested. This camera addresses unique aspects of gamma-ray imaging at nuclear industrial sites, including gamma-ray energies in the 0.5 to 3.0 MeV range and polychromatic fields. Analytic models of camera efficiency, resolution and contaminating events are developed. The response of the camera bears strong similarity to emission computed tomography devices used in nuclear medicine. A direct Fourier based algorithm is developed to reconstruct two-dimensional images of measured gamma-ray fields. Iterative ART and MLE algorithms are also investigated. The point response of the camera to gamma rays of energies from 0.5 to 2.8 MeV is measured and compared to the analytic models. The direct reconstruction algorithm is at least ten times more efficient than the iterative algorithms are also investigated. The point response of the camera to gamma rays energies from 0.5 to 2.8 MeV is measured and compared to the analytic models. The direct reconstruction algorithm is at least ten times more efficient than the iterative algorithms and produces images that are, in general, of the same quality. Measured images of several phantoms are shown. Important results include angular resolutions as low as 4.4{degrees}, reproduction of phantom …

This qualitative study examined the characteristics of the mother-child relationship of adult survivors of childhood sexual abuse at the time of the abuse. The study consisted of data from the McMaster Family Assessment Device (FAD), the Family of Origin Scale (FOS), and a set of structured interview questions designed by the researcher. Autonomy/intimacy concepts from the FOS examined constructs of clarity of expression, responsibility, respect, openness, acceptance of loss and separation, expression of a wide range of feelings, conflict resolution, mood and tone, and empathy.

Information systems research tends to ignore individual differences in users. This laboratory experiment sought to illuminate contributions of decision-makers' cognitive processes to decision outcome as reflected in four hypothesis sets: the impact of imagery preference and presentation format upon (HI) recall accuracy and upon hemispheric activation during (H2) encoding and (H3) recall, and (H4) to examine the relationship between hemispheric activation differences and accuracy differences. Point-value (specific values) and intraset-pattern (relationships between values) recall were considered. Thirty MBA students, grouped by imagery preference (cognitive style) as favoring verbal (textual) or visual (graphical) information presentation, performed computer-based recall tasks using tabular and graphical formats in a repeated measures design. Hemispheric activation (cognitive process) was assessed using ratios of EEG activity in six frequency bands captured from six pairs of homologous electrode sites during encoding and recall.

The purpose of this study was to investigate the ability of trained musicians and musically untrained college students to discriminate music instrument timbre as a function of duration. Specific factors investigated were the thresholds for timbre discrimination as a function of duration, musical ensemble participation as training, and the relative discrimination abilities of vocalists and instrumentalists. Under the conditions of this study, it can be concluded that the threshold for timbre discrimination as a function of duration is at or below 20 ms. Even though trained musicians tended to discriminate timbre better than musically untrained college students, musicians cannot discriminate timbre significantly better then those subjects who have not participated in musical ensembles. Additionally, instrumentalists tended to discriminate timbre better than vocalists, but the discrimination is not significantly different. Recommendations for further research include suggestions for a timbre discrimination measurement tool that takes into consideration the multidimensionality of timbre and the relationship of timbre discrimination to timbre source, duration, pitch, and loudness.

The purpose of this study was to investigate the effects of Project SAIL, a program designed to increase student achievement through interdisciplinary learning, upon the achievement, attendance, and attitude toward school of the ninth grade students who participated in it. The study also identified its benefits and liabilities from the perspective of teachers and students.

The purpose of this study is to examine historically the presidential administration of John Christopher Stevens at Abilene Christian University from 1969 to 1981. During this time the institution grew in enrollment, faculty, facilities, endowment, and quality of educational opportunity. Limited to selected experiences and accomplishments, this dissertation examines Stevens' personal and administrative characteristics through interviews with him and those who worked with him. Materials were also used from Stevens' Presidential Archives in the Callie Faye Milliken Special Collections of the Herman and Margaret Brown Library at Abilene Christian University.

An activity for principal improvement that has not received much attention is the structured management effectiveness profile. The concept is to provide the principal and a group of teachers at that campus with an opportunity for assessment of the principal's management and leadership skills. A comparison between the two provides the principal with information on their perceived management strengths and weaknesses. One such profile, available through the American Association of School Administrators is the Educational Administrator Effectiveness Profile (EAEP). The EAEP was originally given to 66 principals in Tarrant County, Texas. This study reports the results of reassessment of 40 of those principals after a five year period.