You limited your search to:

  Access Rights: Public
  Partner: UNT Libraries
 Collection: UNT Theses and Dissertations
Declining Participation in Fraternity and Sorority Life: a Comparison of Perceptions of Greek-lettered Organizations Between Affiliated and Non-affiliated Students

Declining Participation in Fraternity and Sorority Life: a Comparison of Perceptions of Greek-lettered Organizations Between Affiliated and Non-affiliated Students

Date: May 2014
Creator: Shirley, Zachary E.
Description: This quantitative study was used to determine the perceptions that may have caused a decline in membership in fraternities and sororities and to examine active organization involvement between affiliated and unaffiliated students at a single higher education institution in northeast Texas. Eight perceptions were given regarding fraternity and sorority life and why students chose to remain unaffiliated with fraternities or sororities. The instrument used was a modified version of the Extracurricular Involvement Inventory, created by Winston and Massaro (1987) and was administered to participants online via Survey Monkey. There were 206 participants total: 55.3% were female, and 44.7% were male. Regarding ethnicities, 47.0% were African American, 37.5% were Caucasian, and 15.5% were Hispanic/Latino. Out of the participants, 20.9% were in their freshman or sophomore year, 23.8% were juniors, 33.5% were seniors, and 21.8% were graduate students. Participants’ ages ranged from 18 to 32, with a mean of 22.89 (SD = 2.81). The research questions were analyzed using two techniques: logistic regression for the first question and multiple regression for the second question. Findings for the first research question indicated that lack of values, lack of diversity, poor academic attitudes, and a requirement of too much time were primary reasons unaffiliated ...
Contributing Partner: UNT Libraries
Defining the Contralto Voice Through the Repertoire of Ralph Vaughan Williams

Defining the Contralto Voice Through the Repertoire of Ralph Vaughan Williams

Date: May 2014
Creator: Daniels, Sarah M.
Description: At the beginning of the twentieth century, the recognition of the contralto voice type had reached its apex in England. Throughout the remainder of the century, the number and popularity of recorded contraltos has decreased alongside the rise of the mezzo-soprano voice type. Due to the contralto’s decline and the lack of repertoire composed specifically for the voice, the definition of “contralto” remains somewhat ambiguous. The large contralto repertoire of English composer Ralph Vaughan Williams displays a unique sensitivity to the contralto, particularly with regards to vocal range, flexibility, tessitura, and sustainability. These works thus suggest a new perspective for the voice type. The scope of Vaughan Williams’s oeuvre examined includes each of his operatic roles for contralto and choral works featuring the contralto. Also examined will be the compositional techniques implemented within these pieces which demonstrate the strengths and weaknesses of the contralto voice. A workable definition of the voice type for the pedagogue and performer is included.
Contributing Partner: UNT Libraries
Design and Application of a New Planar Balun

Design and Application of a New Planar Balun

Date: May 2014
Creator: Mohamed, Younes
Description: The baluns are the key components in balanced circuits such balanced mixers, frequency multipliers, push–pull amplifiers, and antennas. Most of these applications have become more integrated which demands the baluns to be in compact size and low cost. In this thesis, a new approach about the design of planar balun is presented where the 4-port symmetrical network with one port terminated by open circuit is first analyzed by using even- and odd-mode excitations. With full design equations, the proposed balun presents perfect balanced output and good input matching and the measurement results make a good agreement with the simulations. Second, Yagi-Uda antenna is also introduced as an entry to fully understand the quasi-Yagi antenna. Both of the antennas have the same design requirements and present the radiation properties. The arrangement of the antenna’s elements and the end-fire radiation property of the antenna have been presented. Finally, the quasi-Yagi antenna is used as an application of the balun where the proposed balun is employed to feed a quasi-Yagi antenna. The antenna is working in the S-band radio frequency and achieves a measured 36% fractional bandwidth for return loss less than -10 dB. The antenna demonstrates a good agreement between its measurement ...
Contributing Partner: UNT Libraries
Design of Tunable/reconfigurable and Compact Microwave Devices

Design of Tunable/reconfigurable and Compact Microwave Devices

Date: May 2014
Creator: Zhou, Mi
Description: With the rapid development of the modern technology, radio frequency and microwave systems are playing more and more important roles. Since the time the first microwave device was invented, they have been leading not only the military but also our daily life to a new era. In order to make the devices have more practical applications, more and more strict requirements have been imposed. For example, good adaptability, reduced cost and shrank size are highly required. In this thesis, three devices are designed based on this requirement. At first, a symmetric four-port microwave varactor based 90-degree directional coupler with tunable coupling ratios and reconfigurable responses is presented. The proposed coupler is designed based on the modified structure of a crossover, where varactors are loaded. Then, a novel reconfigurable 3-dB directional coupler is presented. Varactors and inductors are loaded to the device to realize the reconfigurable performance. By adjusting the voltage applied to the varactors, the proposed coupler can be reconfigured from a branch-line coupler (90-degree coupler) to a rat-race coupler (180 degree coupler) and vice versa. At last, two types (Type-I and Type-II) of microwave baluns with generalized structures are presented. Different from the conventional transmission-line-based baluns where λ/2 transmission ...
Contributing Partner: UNT Libraries
Development and Validation of an Instrument to Operationalize Information System Requirements Capabilities

Development and Validation of an Instrument to Operationalize Information System Requirements Capabilities

Date: May 2014
Creator: Pettit, Alex Z.
Description: As a discipline, information systems (IS) has struggled with the challenge of alignment of product (primarily software and the infrastructure needed to run it) with the needs of the organization it supports. This has been characterized as the pursuit of alignment of information technology (IT) with the business or organization, which begins with the gathering of the requirements of the organization, which then guide the creation of the IS requirements, which in turn guide the creation of the IT solution itself. This research is primarily focused on developing and validating an instrument to operationalize such requirements capabilities. Requirements capabilities at the development of software or the implementation of a specific IT solution are referred to as capabilities for software requirements or more commonly systems analysis and design (SA&D) capabilities. This research describes and validates an instrument for SA&D capabilities for content validity, construct validity, internal consistency, and an exploratory factor analysis. SA&D capabilities were expected to coalesce strongly around a single dimension. Yet in validating the SA&D capabilities instrument, it became apparent that SA&D capabilities are not the unidimensional construct traditionally perceived. Instead it appears that four dimensions underlie SA&D capabilities, and these are associated with alignment maturity (governance, partnership, ...
Contributing Partner: UNT Libraries
Development of a Cost Effective Wireless Sensor System for Indoor Air Quality Monitoring Applications

Development of a Cost Effective Wireless Sensor System for Indoor Air Quality Monitoring Applications

Date: May 2014
Creator: Abraham, Sherin
Description: Poor air quality can greatly affect the public health. Research studies indicate that indoor air can be more polluted than the outdoor air. An indoor air quality monitoring system will help to create an awareness of the quality of air inside which will eventually help in improving it. The objective of this research is to develop a low cost wireless sensor system for indoor air quality monitoring. The major cost reduction of the system is achieved by using low priced sensors. Interface circuits had to be designed to make these sensors more accurate. The system is capable of measuring carbon dioxide, carbon monoxide, ozone, temperature, humidity and volatile organic compounds. The prototype sensor node modules were developed. The sensor nodes were the connected together by Zigbee network. The nodes were developed in such a way that it is compact in size and wireless connection of sensor nodes enable to collect air quality data from multiple locations simultaneously. The collected data was stored in a computer. We employed linear least-square approach for the calibration of each sensor to derive a conversion formula for converting the sensor readings to engineering units. The system was tested with different pollutants and data collected was ...
Contributing Partner: UNT Libraries
Development of High Gain Ultraviolet Photo Detectors Based on Zinc Oxide Nanowires

Development of High Gain Ultraviolet Photo Detectors Based on Zinc Oxide Nanowires

Date: May 2014
Creator: Mallampati, Bhargav
Description: Semiconductor nanowires acts as an emerging class of materials with great potential for applications in future electronic devices. Small size, large surface to volume ratio and high carrier mobility of nanowires make them potentially useful for electronic applications with high integration density. In this thesis, the focus was on the growth of high quality ZnO nanowires, fabrication of field effect transistors and UV- photodetectros based on them. Intrinsic nanowire parameters such as carrier concentration, field effect mobility and resistivity were measured by configuring nanowires as field effect transistors. The main contribution of this thesis is the development of a high gain UV photodetector. A single ZnO nanowire functioning as a UV photodetector showed promising results with an extremely high spectral responsivity of 120 kA/W at wavelength of 370 nm. This corresponds to high photoconductive gain of 2150. To the best of our knowledge, this is the highest responsivity and gain reported so far, the previous values being responsivity=40 kA/W and gain=450. The enhanced photoconductive behavior is attributed to the presence of surface states that acts as hole traps which increase the life time of photogenerated electrons raising the photocurrent. This work provides the evidence of such solid states and preliminary ...
Contributing Partner: UNT Libraries
Does Underwriter Size Matter?  Only Within the Right Context

Does Underwriter Size Matter? Only Within the Right Context

Date: May 2014
Creator: Kendall, Lynn K.
Description: The initial matching relationships between underwriters and bonds/issuing firms and the certification quality of underwriters, as determined by changes in the issuing firm’s financial strength post issue, are the two primary research topics in this dissertation. Based on total underwriter syndicate market share, two distinct categories, low market power (LMP) syndicates and high market power (HMP) syndicates were defined. Firm financial strength is examined based on a new factor developed in this research. A comparison of the two underwriting categories, or pools, indicates that the HMP underwriters take on firms of lower initial financial strength and additionally, the issuing firms decline more in financial strength two years following bond issuance than do firms using LMP underwriters. Notwithstanding these results, the more interesting findings are the relationships within each of these pools. In the LMP pool of underwriters, financially stronger firms used the larger LMPs to underwrite their bonds, while the weaker firms used smaller LMPs. In contrast, among HMP underwriters, the largest HMPs aligned with the firms of relatively lower financial strength. The relationships in both pools reverse when changes in financial strength are examined. Larger LMPs are associated with greater issuing firm financial decline while larger HMPs correlate with ...
Contributing Partner: UNT Libraries
Douglas Campbell: American Horn Pedagogue and Performer

Douglas Campbell: American Horn Pedagogue and Performer

Date: May 2014
Creator: Suchodolski, Heather Blase
Description: While the word “pedagogue” may evoke a vision of an instructor who is dogmatic and set in his own ways, the word descends from Greek origins: ped “child” + agogos “leader.” A pedagogue is, by definition, literally the servant who escorts the child to and from school – the “pedagogue” accompanies the student on the journey for knowledge. True to this definition, Douglas Campbell is model pedagogue – one who gently guided his countless students throughout their musical journeys. As Professor of Music (Horn) at Michigan State University for 45 years, and Horn Instructor at Interlochen Arts Camp for 25 years, Campbell was a significant influence on many developing hornists. Following their study with him, Campbell's students eventually won orchestral and college teaching positions across the United States and throughout the world. Having influenced an extraordinary number of horn students during his tenures at Michigan State University and Interlochen Arts Camp, Douglas Campbell's life and career serve as an excellent example of contemporary horn pedagogy in the United States. This dissertation provides a detailed biography of Douglas Campbell and provides evidence of his contributions to American horn pedagogy, while documenting Campbell’s performing career with the Richards Quintet, which toured the ...
Contributing Partner: UNT Libraries
Dual-band Microwave Device Design

Dual-band Microwave Device Design

Date: May 2014
Creator: Li Shen, Andres E.
Description: This thesis presents a brief introduction to microwave components and technology. It also presents two novel dual-band designs, their analysis, topology, simulation and fabrication. In chapter 2, a novel dual-band bandpass filter using asymmetric stub-loaded stepped-impedance resonators (SLSIRs) operating at 1 and 2.6 GHz is shown. This type of design applies suitable arrangements to improve the filter’s performance. Then, in chapter 3, a novel dual-band balun (transforms unbalanced input signals to balanced output signals or vice versa) operating at 1.1 and 2 GHz with flexible frequency ratios is presented, which has more advantages in microwave applications. Then, conclusion and future works are discussed in chapter 4.
Contributing Partner: UNT Libraries