Automatic Software Test Data Generation

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In software testing, it is often desirable to find test inputs that exercise specific program features. Finding these inputs manually, is extremely time consuming, especially, when the software being tested is complex. Therefore, there have been numerous attempts automate this process. Random test data generation consists of generating test inputs at random, in the hope that they will exercise the desired software features. Often the desired inputs must satisfy complex constraints, and this makes a random approach seem unlikely to succeed. In contrast, combinatorial optimization techniques, such as those using genetic algorithms, are meant to solve difficult problems involving simultaneous satisfaction of many constraints.
Date: December 2002
Creator: Munugala, Ajay Kumar
System: The UNT Digital Library

Cognitive and Perceptual-Motor Indicators of Lateralized vs. Diffuse Brain Damage in Adults.

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Among the goals of the neuropsychological assessment are to detect the presence of brain damage, localize which areas of the brain may be dysfunctional and describe subsequent functional impairments. The sensitivity of neuropsychological instruments in carrying out these functions is a question of some debate. The purpose of this study is to determine the utility of lateralizing indicators from the WAIS-III, McCarron Assessment of Neuromuscular Development (MAND) and Haptic Visual Discrimination Test (HVDT), from the McCarron-Dial System Neuropsychological Assessment Battery (MDS), in ascertaining the presence or absence of brain damage as well as location of lesion. The classification accuracies of using performance level indicators from these tests and lateralizing indicators, alone and together, were compared.
Date: December 2002
Creator: Gregory, Erin Kathleen Taylor
System: The UNT Digital Library

Development, Validation, and Evaluation of a Continuous, Real-time, Bivalve Biomonitoring System

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A biological monitoring tool to assess water quality using bivalve gape behavior was developed and demonstrated. The purpose of this work was to develop methodologies for screening water quality appropriate to the goals of the watershed paradigm. A model of bivalve gape behavior based on prediction of behavior using autoregressive techniques was the foundation of the bivalve biomonitoring system. Current technology was used in developing the system to provide bivalve gape state data in a continuous real-time manner. A laboratory version of the system, including data collection and analysis hardware and software, was developed for use as a toxicological assay for determination of effective concentrations of toxicant(s) or other types of stress on bivalve gape behavior. Corbicula fluminea was monitored and challenged with copper, zinc, and chlorpyrifos using the system. Effective concentrations of 176±23µg/L copper, 768±412µg/L zinc, and 68µg/L chlorpyrifos were observed using a natural water with high dissolved organic carbon concentrations. A rugged field version of the bivalve biomonitoring system was developed and deployed in two locations. The field systems were fitted with a photovoltaic array, a single board computer, and a CDPD telemetry modem for robust remote operation. Data were telemetered at a time relevant rate of once …
Date: December 2002
Creator: Allen, H. Joel
System: The UNT Digital Library

Discovering the Parameters of a Successful Piece: While Developing a Body of Work that Represents My Passion for Clay and My Enthusiasm for Life

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Chapter I describes the purpose of the project, which was to develop a body of work that exhibits all that I am at this point in time. The questions I presented to myself were the following: 1. A successful piece is defined by what parameters? 2. What visual qualities indicate my passion for clay and my enthusiasm for life? Chapter II lists and explains the five parameters of a successful piece, which are composition, firing, mark making, color contrast, and movement. Furthermore there is an explanation on how these parameters visually display my passion for clay and my enthusiasm for life. Chapter III is a summary concluding that by discovering my five parameters of a successful piece I now understand the elements that I am searching for in my work. My work will grow from this understanding as long as I have the same passion for clay and enthusiasm for life.
Date: December 2002
Creator: Lichman, Brenda C.
System: The UNT Digital Library

The Effects of Reinforcing Operant Variability on Task Acquisition

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Neuringer, Deiss, and Olson (2000) was replicated and extended to determine the effect of variability contingencies on task acquisition for twelve 7-9 year old children. Subjects first learned to press a computer's shift keys with increasing response variation. Each subject was then exposed to one of three experimental conditions during which they received a point for target responses. Variability condition subjects received additional points on a variable interval schedule for nontarget responses occurring less than 3% of the time. The any condition subjects received additional points on a variable interval schedule for any nontarget response. Control subjects received points only for target responses. All variability condition and two control subjects learned the target response. All any condition subjects and two control subjects did not.
Date: December 2002
Creator: Seymour, Kail H.
System: The UNT Digital Library

Ensuring Authenticity and Integrity of Critical Information Using XML Digital Signatures

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It has been noticed in the past five years that the Internet use has been troubled by the lack of sufficient security and a legal framework to enable electronic commerce to flourish. Despite these shortcomings, governments, businesses and individuals are using the Internet more often as an inexpensive and ubiquitous means to disseminate and obtain information, goods and services. The Internet is insecure -- potentially millions of people have access, and "hackers" can intercept anything traveling over the wire. There is no way to make it a secure environment; it is, after all, a public network, hence the availability and affordability. In order for it to serve our purposes as a vehicle for legally binding transactions, efforts must be directed at securing the message itself, as opposed to the transport mechanism. Digital signatures have been evolved in the recent years as the best tool for ensuring the authenticity and integrity of critical information in the so called "paperless office". A model using XML digital signatures is developed and the level of security provided by this model in the real world scenario is outlined.
Date: December 2002
Creator: Korivi, Arjun
System: The UNT Digital Library

The Impact of Drug Testing on Secondary School Students

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The purpose of this study determined whether use of student random drug testing provided an effective means to reduce drug usage by secondary school students. The participants included 50,214 7th through 12th grade students in 12 selected public schools. All school districts participated in the Texas School Survey of Substance Use in 1994, 1996, 1998, and 2000. The six districts in the experimental group used drug testing as a method of reducing drug usage among students. The six districts in the control group did not use drug testing. Although athletes and students involved in extracurricular activities remain the focus of random dug testing, this research focused on an entire school population to determine whether drug testing only a select group of students reduced reported drug usage in the entire school. Two questions guided the research: First, does the use of random drug testing have an impact on student drug usage? Second, does the year of implementation of random drug testing have an impact on students' self-reported drug usage? The findings for each research question were categorized according to nine illegal drugs. The researcher used a one-way repeated measures factorial design. The data were analyzed via the univariate (split-plot) 2 x …
Date: December 2002
Creator: Lee, Elton David
System: The UNT Digital Library

Implementation of Back Up Host in TCP/IP

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This problem in lieu thesis is considering a TCP client H1 making a connection to distant server S and is downloading a file. In the midst of the downloading, if H1 crashes, the TCP connection from H1 to S is lost. In the future, if H1 restarts, the TCP connection from H1 to S will be reestablished and the file will be downloaded again. This cannot happen until host H1 restarts. Now consider a situation where there is a standby host H2 for the host H1. H1 and H2 monitor the health of each other by heartbeat messages (like SCTP). If H2 detects the failure of H1, then H2 takes over. This implies that all resources assigned to H1 are now reassigned or taken over by H2. The host H1 and H2 transmit data between each other when any one of it crashed. Throughout the data transmission process, heart beat chunk is exchanged between the hosts when one of the host crashes. In particular, the IP addresses that were originally assigned to H1 are assigned to H2. In this scenario, movement of the TCP connection between H1 and S to a connection between H2 and S without disrupting the TCP …
Date: December 2002
Creator: Golla,Mohan
System: The UNT Digital Library

Integrating life cycle analysis and the ecological footprint calculator to foster sustainable behaviors

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Many tools have been developed to assess global, national or regional sustainable development policies. However, as governments develop sustainable policies, individuals must also feel empowered to affect their personal impact on the planet. This thesis integrates three sustainability concepts that lend themselves to individual sustainability: The natural step, life cycle assessment, and the ecological footprint. TNS serves to provide the meaning and substance toward sustainable development. LCA helps provide the framework for assessing sustainability. The EF calculator determines the driving components and measures the qualitative decisions made through TNS and LCA. From the analysis of the household footprint calculator a simplified footprint calculator was developed to assist individuals and communities in setting benchmarks and goals as they move away from over-consumption and towards a sustainable lifestyle.
Date: December 2002
Creator: Anderle, Kathryn
System: The UNT Digital Library

Investigations of Thermochemistry and the Kinetics of H Atom Radical Reactions

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The thermochemistry of several species, and the kinetics of various H atom radical reactions relevant to atmospheric and combustion chemistry were investigated using ab initio theoretical techniques and the flash photolysis / resonance fluorescence technique. Using ab initio quantum mechanical calculations up to the G3 level of theory, the C-H bond strengths of several alkanes were calculated. The bond strengths were calculated using two working reactions. From the results, it is apparent that the bond strengths decrease as methyl groups are added to the central carbon. The results are in good agreement with recent experimental halogenation kinetic studies. Hydrogen bond strengths with sulfur and oxygen were studied via CCSD(T) theory, together with extrapolation to the complete basis set limit. The results for the bond dissociation energies (ground state at 0 K, units: kJ mol-1) are: S-H = 349.9, S-D = 354.7, HS-H = 376.2, DS-D = 383.4, and HO-H = 492.6. These data compare well with experimental literature. The rate constants for the isotopic reactions of H + H2S, D + H2S, H + D2S, and D + D2S are studied at the QCISD(T)/6-311+G(3df,2p) level of theory. The contributions of the exchange reaction versus abstraction are examined through transition state …
Date: December 2002
Creator: Peebles, Lynda Renee
System: The UNT Digital Library

Layered Double Hydroxides: Morphology, Interlayer Anion, and the Origins of Life

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The preparation of layered double hydroxides via co-precipitation of a divalent/trivalent metal solution against a base results in 1 mm LDH particles with a disorganized metal lattice. Research was performed to address these morphological issues using techniques such as Ostwald ripening and precipitation via aluminate. Another interesting issue in layered double hydroxide materials is the uptake and orientation of anions into the interlayer. Questions about iron cyanide interlayer anions have been posed. Fourier transform infared spectroscopy and powder x-ray diffraction have been used to investigate these topics. It was found that factors such as orientation, anion charge, and anion structure depended on the divalent/trivalent metal ratio of the hydroxide layer and reactivity time. The cyanide self-addition reaction is an important reaction of classical prebiotic chemistry. This reaction has been shown to give rise to amino acids, purines and pyrimidines. At cyanide concentrations similar to that expected on the early earth, hydrolysis to formamide rather than self-addition occurs. One theory to alleviate this side reaction is the use of minerals or clays that are thought to concentrate and catalyze prebiotics of interest. Layered double hydroxides have been studied as a catalyst for this reaction.
Date: December 2002
Creator: Halcom-Yarberry, Faith Marie
System: The UNT Digital Library

Nature By Design

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Organic forms representing nature, but not particular species, are combined with elements signifying attitudes toward the natural world with an emphasis on North American culture. The viewer is encouraged to consider human effects on the environment. Aquarium Night Light and Trophy both refer to the human tendency for commercial exploitation coupled with the creation of nature images we sometimes seem to prefer over the reality of the natural world. Reliquary metaphorically connects traditional religious connotations associated with saints' relics to both a biblical injunction to use anything we needed from the natural world and our contemporary belief that exposure to nature can have beneficial effects on human mental, spiritual, and physical health.
Date: December 2002
Creator: Lingle, Linda A.
System: The UNT Digital Library

Performance Evaluation of MPLS on Quality of Service in Voice Over IP (VoIP) Networks

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The transmission of voice data over Internet Protocol (IP) networks is rapidly gaining acceptance in the field of networking. The major voice transmissions in the IP networks are involved in Internet telephony, which is also known as IP telephony or Voice Over IP (VoIP). VoIP is undergoing many enhancements to provide the end users with same quality as in the public switched telephone networks (PSTN). These enhancements are mostly required in quality of service (QoS) for the transmission of voice data over the IP networks. As with recent developments in the networking field, various protocols came into market to provide the QoS in IP networks - of them, multi protocol label switching (MPLS) is the most reliable and upcoming protocol for working on QoS. The problem of the thesis is to develop an IP-based virtual network, with end hosts and routers, implement MPLS on the network, and analyze its QoS for voice data transmission.
Date: December 2002
Creator: Chetty, Sharath
System: The UNT Digital Library

A Physiological Age-Grading System for Female Hydrellia pakistanae Deonier (Diptera: Ephydridae)

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Conflicting opinions about the effectiveness of H. pakistanae as a biological control agent for hydrilla prompt researchers to find a method for assessing the fly's success. Developing a physiological age-grading system for the fly using ovarian morphology to detect changes in reproductive activity is useful for evaluating reproductive status of the fly in field populations. Changes in the appearance of follicular relics in ovaries with oviposition provide a reliable method to estimate fecundity. Characteristics of follicular relics were used to develop a system with eight physiological age classes, three nulliparous and five parous. Changes that occur in the fat body were used to assist in classification of nulliparous females or those with low egg counts.
Date: December 2002
Creator: Lenz, Jennifer Marie
System: The UNT Digital Library

A Quality of Service Aware Protocol for Power Conservation in Wireless Ad Hoc and Mobile Networks

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Power consumption is an important issue for mobile computers since they rely on the short life of batteries. Conservation techniques are commonly used in hardware design of such systems but network interface is a significant consumer of power, which needs considerable research to be devoted towards designing a low-power design network protocol stack. Due to the dynamic nature of wireless networks, adaptations are necessary to achieve energy efficiency and a reasonable quality of service. This paper presents the application of energy-efficient techniques to each layer in the network protocol stack and a feedback is provided depending on the performance of this new design. And also a comparison of two existing MAC protocols is done showing a better suitability of E2MAC for higher power conservation. Multimedia applications can achieve an optimal performance if they are aware of the characteristics of the wireless link. Relying on the underlying operating system software and communication protocols to hide the anomalies of wireless channel needs efficient energy consumption methodology and fair quality of service like E2MAC. This report also focuses on some of the various concerns of energy efficiency in wireless communication and also looks into the definition of seven layers as defined by International …
Date: December 2002
Creator: Gangidi, Murali
System: The UNT Digital Library

Ranges of consideration: crossing the fields of ecology, philosophy and science studies.

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Environmental issues are often complex with many different constituents operating according to a broad range of communication techniques. In order to foster negotiations, different perspectives need to be articulated in lucid ways sensitive to various viewpoints and circumstances. In my thesis I investigate how certain approaches to environmental discourse effect dialogue and negotiation. My first two chapters focus on environmental problems surrounding rangeland ecology along the U.S./Mexico border; whereas the last two chapters explore more theoretical conflicts concerning the philosophy of nature. Throughout the thesis I show the significance of nonhumans (prairie dogs, cattle, biological assessment sheets, environmental laws, etc.) in the human community. Only by considering the roles of nonhumans do we broaden and enrich the conversation between ourselves concerning environmental issues.
Date: December 2002
Creator: Dinneen, Nathan
System: The UNT Digital Library

The relationship between training in learning style adaptation and successful completion of entry-level community college classes.

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The purpose of this study was to determine if there was a relationship between training in learning style adaptation and successful completion of community college courses. The rationale for conducting this study was based on the need for students to learn how to adapt their learning style in order to more effectively learn in any situation. It is also important that community colleges implement strategies that assist in student retention. The learning styles of entry-level community college students were measured using Kolb's Learning Style Inventory Version 3. Students enrolled in entry-level college courses at a small North Texas community college were studied. The Chi-square Test of Independence with a 2 x 2 design was employed. Findings indicated that there was no statistically significant difference in the relationship between students receiving training in learning styles adaptation and successful completion of entry-level college courses, and that students who attended a learning styles training session and those who did not attend a learning styles training session had an equal chance of succeeding in entry-level community college courses. Findings also indicated that students with Accommodating and Assimilating learning styles are less likely to successfully complete an entry-level college course than are students with Diverging …
Date: December 2002
Creator: Ferrell, Dawn M.
System: The UNT Digital Library

Removal of selected water disinfection byproducts, and MTBE in batch and continuous flow systems using alternative sorbents.

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A study was conducted to evaluate the sorption characteristics of six disinfection byproducts (DBPs) on four sorbents. To investigate sorption of volatile organic compounds (VOCs), specially designed experimental batch and continuous flow modules were developed. The investigated compounds included: chloroform, 1,2-dichloroethane (DCE), trichloroethylene (TCE), bromodichloromethane (BDCM), methyl tertiary butyl ether (MTBE), bromate and bromide ions. Sorbents used included light weight aggregate (LWA), an inorganic porous material with unique surface characteristics, Amberlite® XAD-16, a weakly basic anion exchange resin, Amberjet®, a strongly basic anion exchange resin, and granular activated carbon (GAC). Batch experiments were conducted on spiked Milli-Q® and lake water matrices. Results indicate considerable sorption of TCE (68.9%), slight sorption of bromate ions (19%) and no appreciable sorption for the other test compounds on LWA. The sorption of TCE increased to 75.3% in experiments utilizing smaller LWA particle size. LWA could be a viable medium for removal of TCE from contaminated surface or groundwater sites. Amberlite® was found unsuitable for use due to its physical characteristics, and its inability to efficiently remove any of the test compounds. Amberjet® showed an excellent ability to remove the inorganic anions (>99%), and BDCM (96.9%) from aqueous solutions but with considerable elevation of pH. …
Date: December 2002
Creator: Kadry, Ahmed Y.
System: The UNT Digital Library

Server load balancing.

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Server load balancing technology has obtained much attention as much business proceeded towards e-commerce. The idea behind is to have set of clustered servers that share the load as against a single server to achieve better performance and throughput. In this problem in lieu of thesis, I propose and evaluate an implementation of a prototype scalable server. The prototype consists of a load-balanced cluster of hosts that collectively accept and service TCP connections. The host IP addresses are advertised using the Round Robin DNS technique, allowing any host to receive requests from any client. Once a client attempts to establish a TCP connection with one of the hosts, a decision is made as to whether or not the connection should be redirected to a different host namely, the host with the lowest number of established connections. This problem in lieu of thesis outlines the history of load balancing, various options available today and finally approach for implementing the prototype and the corresponding findings.
Date: December 2002
Creator: Kanuri, Jaichandra
System: The UNT Digital Library

The Tone Clock: Peter Schat's System and an Application to His Etudes for Piano and Orchestra, Opus 39

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The scope of this study includes relevant background information on Peter Schat and his compositions and process, an explanation of the Tone Clock system and a detailed analysis of one of his compositions, the Etudes for Piano and Orchestra, Opus 39. The intent is to demonstrate how the Tone Clock naturally evolved from the practices of the Second Viennese School and how it relates to both new and existing modern music. The study is divided into five chapters. Chapter 1 presents a brief introduction to Peter Schat and the Tone Clock. Chapter 2 provides a more detailed biography of Peter Schat and traces the development and evolution of his compositional techniques, ultimately culminating in the Tone Clock. Chapter 3 provides a basic explanation of the Tone Clock itself, with demonstrations of various components through musical examples and illustrations. Chapter 4 is a detailed analysis of the Etudes for Piano and Orchestra, Opus. 39. Chapter 5 summarizes the results of the study, with special attention to the impact of the Tone Clock on performance from the perspective of the performer. The analysis of the Etudes was completed by using the Tone Clock as an analytical tool, aided by the composer's original …
Date: December 2002
Creator: Petrella, Diane Helfers
System: The UNT Digital Library

Wisdom and Law: Political Thought in Shakespeare's Comedies

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In this study of A Midsummer Night's Dream, The Merchant of Venice, and Measure for Measure I argue that the surface plots of these comedies point us to a philosophic understanding seldom discussed in either contemporary public discourse or in Shakespearean scholarship. The comedies usually involve questions arising from the conflict between the enforcement of law (whether just or not) and the private longings (whether noble or base) of citizens whose yearnings for happiness tend to be sub- or even supra-political. No regime, it appears, is able to respond to the whole variety of circumstances that it may be called upon to judge. Even the best written laws meet with occasional exceptions and these ulterior instances must be judged by something other than a legal code. When these extra-legal instances do arise, political communities become aware of their reliance on a kind of political judgment that is usually unnoticed in the day-to-day affairs of public life. Further, it is evident that the characters who are able to exercise this political judgment, are the very characters whose presence averts a potentially tragic situation and makes a comedy possible. By presenting examples of how moral and political problems are dealt with by …
Date: December 2002
Creator: Major, Rafael M.
System: The UNT Digital Library

Application of Thermomechanical Characterization Techniques to Bismuth Telluride Based Thermoelectric Materials

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The thermoelectric properties of bismuth telluride based thermoelectric (TE) materials are well-characterized, but comparatively little has been published on the thermomechanical properties. In this paper, dynamic mechanical analysis (DMA) and differential scanning calorimetry data for bismuth telluride based TE materials is presented. The TE materials' tan delta values, indicative of viscoelastic energy dissipation modes, approached that of glassy or crystalline polymers, were greater than ten times the tan delta of structural metals, and reflected the anisotropic nature of TE materials. DMA thermal scans showed changes in mechanical properties versus temperature with clear hysteresis effects. These results showed that the application of DMA techniques are useful for evaluation of thermophysical and thermomechanical properties of these TE materials.
Date: August 2002
Creator: White, John B.
System: The UNT Digital Library

Breaking Through: A Composition for Symphony Orchestra

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Breaking Through is a single-movement composition for symphony orchestra based on a fourteen-note melody. Every harmonic and melodic figure except the bass line is derived from this source melody. The structure of the work is based on a number of musical dichotomies that work on both local and large-scale levels. The local dichotomies contrast consonance with dissonance and ambiguity with clarity (in respect to texture and rhythm). The dichotomy of two-part form versus three-part form and the dichotomy of simplicity versus complexity operate on the large scale. The unity lended by the single source melody coupled with the contrasts furnished by the aforementioned dichotomies allow Breaking Through to be both coherent and interesting.
Date: August 2002
Creator: Dribus, John Alexander
System: The UNT Digital Library

Changing Privacy Concerns in the Internet Era.

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Privacy has always been a respected value regardless of national borders, cultural differences, and time in every society throughout history. This study focuses on the unprecedented changes in the traditional forms of privacy and consequent concerns with regard to invasion of privacy along with the recent emergence and wide use of the Internet. Government intrusion into private domains through the Internet is examined as a major concern. Privacy invasions by Web marketers, hacker threats against privacy, and employer invasion of employee privacy at the workplace are discussed respectively. Then a set of possible solutions to solve the current problems and alleviate the concerns in this field is offered. Legal remedies that need to be performed by the government are presented as the initial solution. Then encryption is introduced as a strong technical method that may be helpful. Finally, a set of individual measures emphasized as complementary practical necessities. Nevertheless, this study indicates that technology will keep making further changes in the form and concerns of privacy that possibly may outdate these findings in the near future, however, privacy itself will always remain as a cherished social value as it has always been so far.
Date: August 2002
Creator: Demir, Irfan
System: The UNT Digital Library