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Judgment of Intonation in the Context of Three-Part Woodwind Ensemble Performances

Description: The purpose of the study was to determine judgments of trained musicians regarding the intonation of complex tones in the context of synthesized woodwind ensemble performances. Problems included in the study were (1) estimation of the point in pitch deviation which would result in out-of-tune judgments, (2) investigation of timbral effects on judged intonation, and (3) investigation of effects of mistuning within differential voices.
Date: August 1987
Creator: Henry, Robert E.
Partner: UNT Libraries
open access

Academic Achievement and the Ability of Post-Secondary Students to Read Assigned Materials

Description: This study provides a rationale for adopting course materials. It demonstrates the relationship between ability to read assigned materials and academic achievement, and that selection of materials creates two groups having different probabilities of success. The sample was selected from a population of all students enrolled in Principles of Economics courses at North Texas State University in the spring semester of 1986. The Nelson-Denny Reading Test was used to determine reading ability. Assigned materials were analyzed for readability. A frustration level was determined and used to divide the sample: the group of interest, those with reading abilities below the frustration level who underwent the treatment of reading materials written above their ability to comprehend; and the comparison group, those with reading abilities above the frustration level who did not undergo the treatment.
Date: August 1987
Creator: Cohick, Mikel William
Partner: UNT Libraries
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A Comparative Analysis of Guided vs. Query-Based Intelligent Tutoring Systems (ITS) Using a Class-Entity-Relationship-Attribute (CERA) Knowledge Base

Description: One of the greatest problems facing researchers in the sub field of Artificial Intelligence known as Intelligent Tutoring Systems (ITS) is the selection of a knowledge base designs that will facilitate the modification of the knowledge base. The Class-Entity-Relationship-Attribute (CERA), proposed by R. P. Brazile, holds certain promise as a more generic knowledge base design framework upon which can be built robust and efficient ITS. This study has a twofold purpose. The first is to demonstrate that a CERA knowledge base can be constructed for an ITS on a subset of the domain of Cretaceous paleontology and function as the "expert module" of the ITS. The second is to test the validity of the ideas that students guided through a lesson learn more factual knowledge, while those who explore the knowledge base that underlies the lesson through query at their own pace will be able to formulate their own integrative knowledge from the knowledge gained in their explorations and spend more time on the system. This study concludes that a CERA-based system can be constructed as an effective teaching tool. However, while an ITS - treatment provides for statistically significant gains in achievement test scores, the type of treatment seems not to matter as much as time spent on task. This would seem to indicate that a query-based system which allows the user to progress at their own pace would be a better type of system for the presentation of material due to the greater amount of on-line computer time exhibited by the users.
Date: August 1987
Creator: Hall, Douglas Lee
Partner: UNT Libraries
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A Behavioral Modification Analysis of the Effects of Multimedia First Aid Training on Injuries in an Industrial Setting

Description: Past research has shown a correlation between first-aid training and the reduction of injuries. This connection has been noted in off-the-job situations in addition to industrial studies. This project is an extension of those past findings with three notable differences: total population training was studied, as the intervention instead of just saturation treatment; attention was given to the effect that the half-life of training had upon injury reduction; and three randomly chosen small groups we're studied to determine short range effects. The theoretical bases from which the study hypothesis was developed originated in the Behavioral Science and Psychology literature. Discussions are developed around the mental structuring of accidental potential situations in the case of a person trained in first-aid principles. Behavior Modification was one of the principles of change that offered a.safer environment through first-aid training. Group contagion provided the setting for development of a safer place to work because of socialization to a "safe attitude." The intervention, American National Red Cross Standard Multimedia First-Aid Course, provided some of the mental developments toward modification of behavior. These were the modeling and rehearsal features of the course. A connection between group deviance and accident "proneness" led to a proposal that avoidance behavior was the resultant of the training.
Date: May 1987
Creator: Sturrock, James Lee
Partner: UNT Libraries
open access

An Experimental Investigation into the Interaction Between Modality Preference and Instruction Mode in the Learning of Spelling Words by Upper-Elementary Learning Disabled Students

Description: This study investigated the effects of selected spelling teaching methods on spelling mastery of upper-elementary, learning disabled students. It also examined the value of assessing learning disabled students' modality preferences for diagnostic/prescriptive purposes.The study's significance is that it sought to (a) determine whether students classified as learning disabled can identify their preferred learning modes; (b) determine whether matching modes of instruction to students' modality reference(s) results in greater achievement; and (c) identify a systematic way of prescribing instruction for learning disabled students.
Date: August 1987
Creator: Hill, Gerald D. (Gerald Dean)
Partner: UNT Libraries
open access

Therapeutic Effects of Group Counseling with Visually-Impaired Elderly Adults

Description: The purpose of this study was twofold: (a) to determine the therapeutic effectiveness of group counseling with visually-impaired elderly adults, and (b) to provide information concerning the effectiveness of group counseling to practitioners in the field. The study reviewed the literature regarding aging and vision, psychosocial reactions to vision loss, and group counseling with the visually-impaired and the elderly. Twenty subjects, who were above age 65 and had recently experienced a severe loss of vision, were selected to participate in the study. Ten subjects were assigned to an experimental counseling group and 10 subjects were assigned to a no-treatment control group. The experimental group participated in 1-1/2 hour group sessions once a week for 10 weeks. Both the experimental group and the control subjects were administered pre- and post-tests. The tests measured depression, anxiety, self-esteem, and life satisfaction.
Date: December 1987
Creator: Schor, Mark Melvin
Partner: UNT Libraries
open access

Comparison of Methods for Computation and Cumulation of Effect Sizes in Meta-Analysis

Description: This study examined the statistical consequences of employing various methods of computing and cumulating effect sizes in meta-analysis. Six methods of computing effect size, and three techniques for combining study outcomes, were compared. Effect size metrics were calculated with one-group and pooled standardizing denominators, corrected for bias and for unreliability of measurement, and weighted by sample size and by sample variance. Cumulating techniques employed as units of analysis the effect size, the study, and an average study effect. In order to determine whether outcomes might vary with the size of the meta-analysis, mean effect sizes were also compared for two smaller subsets of studies. An existing meta-analysis of 60 studies examining the effectiveness of computer-based instruction was used as a data base for this investigation. Recomputation of the original study data under the six different effect size formulas showed no significant difference among the metrics. Maintaining the independence of the data by using only one effect size per study, whether a single or averaged effect, produced a higher mean effect size than averaging all effect sizes together, although the difference did not reach statistical significance. The sampling distribution of effect size means approached that of the population of 60 studies for subsets consisting of 40 studies, but not for subsets of 20 studies. Results of this study indicated that the researcher may choose any of the methods for effect size calculation or cumulation without fear of biasing the outcome of the metaanalysis. If weighted effect sizes are to be used, care must be taken to avoid giving undue influence to studies which may have large sample sizes, but not necessarily be the most meaningful, theoretically representative, or elegantly designed. It is important for the researcher to locate all relevant studies on the topic under investigation, since selective or even random …
Date: December 1987
Creator: Ronco, Sharron L. (Sharron Lee)
Partner: UNT Libraries
open access

Forecasting Future Events Affecting One Institution of Higher Education in the State of Texas: A Delphi Application

Description: The purpose of this study was to investigate the possible events in the external environment between 1987 and 1997 that may affect the future of North Texas State University. Two groups of experts participated in the study, a group of individuals from outside North Texas State University and a group of experts from the university.
Date: December 1987
Creator: Bollinger, Julie R., 1952-
Partner: UNT Libraries
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A Comparative Study of Children's Intensity of Task-Involvement in a Selected Nursery School

Description: The problem of this study was a comparison of young children's intensity of task—involvement in child—selected activities. A group of 23 children, four to six years of age, was selected as the subjects from a university affiliated child development laboratory school. These children were observed during child-selected activities for five consecutive weeks. The instrument utilized to collect the data was the Intensity Of Involvement Scale, composed of seven categories of intensity from "Unoccupied" to "Complete." To obtain reliable data, two observers were involved in the observation and a carefully planned procedure of observation was followed accurately. The comparison of children's intensity of task-involvement among child-selected activities, using statistical methods of mean and standard deviation, yielded a similar result among various groups of children. The learning centers in which children were involved most intensely were water play, family living, manipulative, and art centers. The children, however, were involved in the reading, block, and writing centers less intensely. In comparing children's intensity of task-involvement between age-groups and sex-groups, the analyses of two-way t-test revealed that age-differences were significant (p<.05) but sex-differences were not significant in children's overall intensity of task-involvement. Also, the results showed that the significance of differences in children's intensity of task-involvement in each child-selected activity depended more upon the age than the sex of children. In addition, individual differences in children's intensity of task-involvement were examined using mean, frequency distribution, and range. The finding was that children differed from one another in their degrees and variability of intensity of task-involvement in child-selected activities.
Date: August 1987
Creator: Roan, Bi-Sho
Partner: UNT Libraries
open access

Gender and Earnings: Examining the Earnings Gap Between Men and Women Across Metropolitan Labor Markets

Description: The earnings gap between men and women, an apt indicator of women's status relative to men's, was roughly constant for the thirty-five years between 1950 and 1985. During this period women earned about 60 to 65 cents for every dollar earned by men. The purpose of this study is to analyze the determinants of this wage gap. Because much existing research suggests that a large portion of the gender gap in pay results from the segregation of women into low-paying jobs, the present study focuses on the role of gender segregation in the workplace. Other potential contributors to the earnings gap are also examined (women's domestic obligations, educational attainment, women's labor force participation rates, and the industrial mix in Standard Metropolitan Statistical Areas). The position of women as a group in the labor market is of primary interest in this research. Accordingly, the analysis was conducted on an aggregate level across labor markets. The data were drawn from the Bureau of the Census Census of the Population: 1980—Detailed Population Characteristics. The project uses a cross-sectional research design, the primary statistical technique used being multiple regression analysis. Findings reveal that workplace segregation and the industrial characteristics of SMSA labor markets have the strongest effect on the size of the gender-based earnings gap. Specifically, workplace segregation is positively related to the size of the earnings gap between men and women. The presence of above average levels of manufacturing activity in an SMSA is associated with a larger earnings gap while the presence of above average levels of service sector and government employment opportunities in an SMSA is associated with smaller earnings differentials between men and women. This study enhances the understanding of the effects of structural variables on the earnings determination process for men and women and provides insight into the collective …
Date: December 1987
Creator: Dunn, Dana
Partner: UNT Libraries
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Spółka Nakładowa Młodych Kompozytorów Polskich (1905-1912) and the Myth of Young Poland in Music

Description: This study deals with the four-composer Polish musical association, Young Polish Composers' Publishing Company, which became commonly known as the group Poland in Music. Young Poland in Music is considered by Polish and non-Polish music historians to be the signal inaugurator of modernism in Polish music. However, despite this most important attribution, the past eighty-odd years have witnessed considerable confusion over the perceptions of: 1) exactly who constituted the publishing company, 2) why it was founded, 3) what the intentions of its members were, and 4) the general reception its members' music received. This paper addresses and resolves this multiple confusion. Chapter I presents an introductory survey of the political, socio/cultural, and musical developments of Poland between 1772 and c1900, the period of the Polish Partitions through the beginnings of the "Young Poland" era. Chapter II presents a discussion of the facts surrounding the founding of the publishing company, as well as a discussion of the eighty-odd years of historical misinterpretations that have developed about the composers' company and its relationship to "Young Poland in Music." Chapter III discusses the interpersonal relationships of the composers and other persons directly involved with them and their company, and the impact that these relationships had on the publishing company. Additionally, the chapter brings into focus the specific relationships between the musicologist, Adolf Chybiński, the company, and its individual members. The chapter concludes with a discussion of the actual publishing activities of the company. Chapter IV examines the three concerts sponsored by the company and their critical receptions in Warsaw and Berlin through the surviving reviews and comments of leading contemporary music critics, the concert participants, the composers' close colleagues, and the composers themselves. Finally, Chapter V contains a brief discussion of the music presented on the three concerts, characterizing the works within the …
Date: December 1987
Creator: Hebda, Paul Thomas
Partner: UNT Libraries
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Two Photon Resonant Picosecond Pulse Propagation in Lithium Vapor

Description: The work of this dissertation has been to prove that the coherence of multiphoton excitation can be studied by an appropriately phased and time delayed sequence of pulses. An application of this fundamental study of coherence has been made for the enhancement of third harmonic generation. The coherent recovery of the energy lost to the two photon absorption process enalled a larger propagation distance for the fundamental than in an interaction which is incoherent or coherent, but not using a 90 degree phase shifted pulse pair. Phase matching over this longer propagation distance gave an enhancement of third harmonic generation.
Date: August 1987
Creator: Mukherjee, Anadi
Partner: UNT Libraries
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The Relationship of Locus of Control Orientation to the Academic Achievement of Doctoral Students

Description: This study sought to determine the extent a relationship exists between locus of control and the rate of completion for proposal and dissertation defense among doctoral students. Levenson's Internal, Powerful Others, and Chance scales were utilized to identify locus of control orientation. Findings indicated that: (1) a majority, 102, scored highest on the Internal scale; (2) Internal scale scores above the median related to increased probability of a proposal and dissertation defense and to reduced time in reaching those points; (3) no significant difference was found between male and female defensive externals in completing the proposal or dissertation defense; and (4) females tended to score higher than males on the Internal scale. Among conclusions drawn are: (1) Internal scale scores above the median relate to a reduced length of time to complete the proposal and dissertation defense; and (2) few doctoral candidates scoring higher on the Powerful Others or Chance scales were identified in this doctoral program after the point of qualifying examinations.
Date: May 1987
Creator: Wentzel, Marcela Luise
Partner: UNT Libraries
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The Departing Experience: a Qualitative Study of Personal Accounts by Women Who Are Former Athletic Directors of Intercollegiate Athletic Programs for Women

Description: What happened to women who are former athletic directors of intercollegiate athletic programs during each of the four stages of the departing experience was the problem of this study. A qualitative design using personal interviews for data collection and ethnoscientific explanation for analysis of the data were used to study thirty-one women who were athletic directors between 1975 and 1986. Analytical tasks performed for each of the four levels of analysis helped answer research questions directed toward finding patterns among women in the following areas: what happened to them within and throughout the four stages of the departing experience, reasons they left the position of athletic director, and satisfaction in their subsequent job. Analysis of the data established that the departing experience occurred in four stages. How the subjects responded to the way that opportunities for female student-athletes were offered during each st3ge of the departing experience determined whether they were in positive or negative circumstances. Sixteen subjects either were in positive circumstances throughout the departing experience or ended it in positive circumstances. Fifteen subjects were either in negative circumstances throughout the departing experience or ended it in negative circumstances. The ability to reevaluate their beliefs and values, adapt to changes in their programs, make rational decisions, and influence others to support their decisions determined whether they were in positive or negative circumstances in each stage of the departing experience. In general, the findings of this study support literature on women in administrative positions and literature on the effects of job loss and job change.
Date: December 1987
Creator: Disselkoen, Jackie M.
Partner: UNT Libraries
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Six Odes by C.F. Gellert set by C.P.E. Bach and Ludwig van Beethoven: A Comparative Analysis, a Lecture Recital Together with Three Recitals of Selected Works by Monteverdi, Caldara, Mozart, Brahms, Mendelssohn, Ives, Honegger, and Others

Description: The lecture recital was given on July 13, 1987. The discussion of the poetry by C. F. Gellert and the musical settings by C. P. E. Bach and Ludwig van Beethoven including analyses of all the pieces was followed by their performance. In addition to the lecture recital, three other public recitals were given: three of solo literature for voice and piano and one of vocal chamber literature. These included the works of Monteverdi, Caldara, Mozart, Brahms, Strauss, Mendelssohn, Ives, Honegger, Debussy, Faure", and others. All of these recitals were recorded on magnetic tape and filed along with the written version of the lecture material as a part of the dissertation.
Date: August 1987
Creator: Seelig, Timothy
Partner: UNT Libraries
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The Impact of a Nursing Program on Stress, Physical Illness, Anxiety, and Self-Concept of Participants in a Community College Nursing Program

Description: This research study was designed to investigate the relationship between participation in a nursing education program and the factors of stress, physical illness, anxiety, and self-concept experienced by the participants. Also, the study examined the relationship between age of participants and these same factors. The purposes of this study were (1) to determine if beginning and ending nursing students differ in stress, physical illness, anxiety, and self-concept, (2) to examine the relationship between age of nursing students and stress, physical illness, anxiety, and self-concept, (3) to provide information that may help develop a theoretical base concerning stressful life events and illness in nursing students, and (4) to provide information that may be beneficial with regard to future research involving stress, physical illness, anxiety, self-concept, and age in nursing students.
Date: May 1987
Creator: Gray, Sylvia Jane
Partner: UNT Libraries
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Studies on Hog Plasma Lecithin:cholesterol Acyltransferase: Isolation and Characterization of the Enzyme

Description: Lecithin:cholesterol acyltransferase (LCAT) was isolated from hog plasma and basic physicochemical properties and functionally important regions were investigated. Approximately one milligram of the enzyme was purified to apparent homogeneity with approximately a 20,000-fold increase in specific activity. In the plasma, hog LCAT was found to associate with high-density lipoproteins (HDL) probably through hydrophobic interactions with apolipoprotein A-I. HDL was the preferred lipoprotein substrate of the enzyme as its macromolecular substrate. The enzyme was found to contain 4 free sulfhydryl groups; at least one of these appeared to be essential for catalytic activity. The enzyme had a tendency to aggregate at high concentrations. More than half of the tryptophan and none of the tyrosine residues of the enzyme were shown to be exposed to the aqueous environment based on fluorescence and absorbance studies, respectively.
Date: May 1987
Creator: Park, Yong Bok
Partner: UNT Libraries
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An Analysis of the Utilization of Needs Assessments by Training and Development Professionals

Description: The purpose of this study was to analyze the utilization of needs assessments by training and development professionals in a large metropolitan training association. The study sought to determine (1) how frequently needs assessments were used; (2) how the results of needs assessments were used; (3) whether the needs assessment model was developed by in-house staff or outside consultants; (4) whether needs assessments were utilized more frequently within specific industry groups; and (5) the respondents' perceived level of importance placed on the needs assessment process. To accomplish these objectives, this study surveyed members of the Dallas chapter of the American Society for Training and Development (ASTD).
Date: May 1987
Creator: Hires, Teri Meadows
Partner: UNT Libraries
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The Attitudes of International Students Toward University Withdrawal

Description: The purpose of this study was to determine if significant differences existed in attitudes of international students concerning college withdrawal. Data collection involved 200 freshmen international students from two universities in Texas. Two questionnaires were distributed to the students to determine attitudes toward college withdrawal. The instrument used to score the attitudes was the Purdue Master Attitude Scale. The analysis of variance was used for the statistical evaluation. The statistics indicated there was no significant differences between the students tested in the study and that the students had favorable attitudes toward college and unfavorable attitudes toward college withdrawal. Based on the findings of this study, universities should devise an extensive counseling and orientation program in order to provide students opportunities to complete their college education.
Date: December 1987
Creator: Ghoreyshi, Mohammad
Partner: UNT Libraries
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Neuropharmacological Characteristics of Tolerance for Cocaine Used as a Discriminative Stimulus

Description: The main purpose of this research was to investigate the phenomenon of tolerance to cocaine. Tolerance is operationally defined as a decreased drug effect due to prior history of drug administration. The animal model that was chosen to investigate tolerance to cocaine was the drug discrimination model, which is an animal analogue of human subjective drug effects. In the drug discrimination procedure, animals are trained to emit one behavior when injected with saline. In the present experiments, rats were trained to press one lever when injected with cocaine, 10 mg/kg, and a different lever when injected with saline for food reinforcement. Once rats are trained, they can accurately detect the cocaine stimulus greater than 95% of the time.
Date: August 1987
Creator: Wood, Douglas M. (Douglas Michael)
Partner: UNT Libraries
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Holistic Evaluation of Peer Writings by Able and Less Able Readers in Eighth and Tenth Grades

Description: The purpose of this study was to examine the use of general impression scoring by teachers and students, and to compare the criteria used in evaluating student writings. Subjects for the study were 40 eighth grade and tenth grade students of varying reading ability in regular English classes in a suburban school district. Teachers and students evaluated two sets of writings in the narrative, classificatory and descriptive modes, generated by ninth grade students in regular English classes in the same school district. In addition, a comment, citing criteria upon which evaluation was based, was made on each writing. The design for this study was an extended factorial analysis. A three way analysis of variance was computed for ability and grade for each level of quality of writing in each mode of discourse. Six hypotheses were tested. Hypotheses one and two dealt with comparison of ratings by students who differed by ability and grade. No significant differences were found. Hypotheses three and four dealt with interaction between grade, ability and mode of discourse. No significant interaction was found. Hypotheses five and six dealt with differences in evaluations between teachers and students of varying ability. A significant difference was found in how teachers and students evaluate writing (p .01). Examination of criteria used in evaluating writings indicated that teachers consistently referred to elements of the text. Students also made text-based comments. In addition, students responded subjectively, referring to common experience, interest, and memories cued by the text.
Date: August 1987
Creator: Peters, Elaine
Partner: UNT Libraries
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Invertible Ideals and the Strong Two-Generator Property in Some Polynomial Subrings

Description: Let K be any field and Q be the rationals. Define K^1[X] = {f(X) e K[X]| the coefficient of X in f(X) is zero} and Q^1β[X] = {f(X) e Q[X]| the coefficent of β1(X) in the binomial expansion of f(X) is zero}, where {β1(X)}^∞ i=0 are the well-known binomial polynomials. In this work, I establish the following results: K^1[X] and Q^1β[X] are one-dimensional, Noetherian, non-Prüfer domains with the two-generator property on ideals. Using the unique factorization structure of the overrings K[X] and Q[X], the nonprincipal ideal structures of both rings are characterized, and from this characterization, necessary and sufficient conditions are found for a nonprincipal ideal to be invertible. The nonprincipal invertible ideals are then characterized in terms of the coefficients of the generators, and an explicit formula for the inverse of any proper invertible ideal is found. Finally, the class groups of both rings are shown to be torsion free abelian groups. Let n be any nonnegative integer. Results similar to the above are found in the generalizations of these two rings, K^n[X] and q^nβ[X], where the coefficients on the first n nonconstant basis elements are zero. For the domains K^1[X] and Q^1β[X], the property of strong two-generation is explored in detail and the following results are established: 1. K^1[X] and Q^1β[X] are not strongly two-generated, 2. In either ring, any polynomial with a constant term, or of degree two or three is a strong two-generator. 3. In K^1[X] any polynomial divisible by X^4 is not a strong two-generator, 4. An ideal I in K^1[X] or Q^1β[X] is strongly two-generated if and only if it is invertible.
Date: May 1987
Creator: Chapman, Scott T. (Scott Thomas)
Partner: UNT Libraries
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An Investigation of Asymmetrical Power Relationships Existing in Auditor-Client Relationship During Auditor Changes

Description: In recent years, considerable interest has been stimulated concerning potential conflicts of interest between a company's management and their independent auditors. Many researchers examined the association between corporations who changed their present auditors, and factors such as auditor's opinion on the financial statements, management changes, mergers, financial distress, etc. Some of these research efforts resulted in findings that were inconsistent with each other. The current research was therefore undertaken with the objective of developing a theoretical model of auditor change process and to explain the justification for considering certain specific factors that may be present in an auditor-client relationship. The research design and the methodology for analyses were developed on the basis of the theory on power conflicts found in political science literature and by the use of Wrong's power model on authority relationship. Sources of power such as the size of an audit firm, size of a corporation, the stock exchange membership, the ability of an auditor to qualify the opinion on the financial statements, the ability of the management of a corporation to terminate the audit contract following the issue of a qualified opinion, and change of a corporation's CEO were identified and converted into independent variables. Data were collected from secondary sources on a sample of 200 corporations, 100 companies that had changed their audit firm at least once during the period 1983-85, and 100 corporations that did not change their audit firm during this period. The resulting data were analyzed using the MDS-ALSCAL procedure and logit regression with maximum likelihood estimators. The findings of this research support the power model and its relevancy to the study of auditor-client relationship. The variables, client size, stock exchange membership, and audit firm size were found to have a significant association with corporations who changed their audit firms. However, the …
Date: August 1987
Creator: Sriram, Srinivasan
Partner: UNT Libraries
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Photon Exchange Between a Pair of Nonidentical Atoms with Two Forms of Interactions

Description: A pair of nonidentical two-level atoms, separated by a fixed distance R, interact through photon exchange. The system is described by a state vector which is assumed to be a superposition of four "essential states": (1) the first atom is excited, the second one is in the ground state, and no photon is present, (2) the first atom is in its ground state, the second one is excited, and no photon is present, (3) both atoms are in their ground states and a photon is present, and (4) both atoms are excited and a photon is also present. The system is initially in state (1). The probabilities of each atom being excited are calculated for both the minimally-coupled interaction and the multipolar interaction in the electric dipole approximation. For the minimally-coupled interaction Hamiltonian, the second atom has a probability of being instantaneously excited, so the interaction is not retarded. For the multipolar interaction Hamiltonian, the second atom is not excited before the retardation time, which agrees with special relativity. For the minimally-coupled interaction the nonphysical result occurs because the unperturbed Hamiltonian is not the energy operator in the Coulomb gauge. For the multipolar Hamiltonian in the electric dipole approximation the unperturbed Hamiltonian is the energy operator. An active view of unitary transformations in nonrelativistic quantum electrodynamics is used to derive transformation laws for the potentials of the electromagnetic field and the static Coulomb potential. For a specific choice of unitary transformation the transformation laws for the potentials are used in the minimally-coupled second-quantized Hamiltonian to obtain the multipolar Hamiltonian, which is expressed in terms of the quantized electric and magnetic fields.
Date: May 1987
Creator: Golshan, Shahram Mohammad-Mehdi
Partner: UNT Libraries
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