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Resource-Efficient and Robust Distributed Computing
No full textThere has been a tremendous growth in the size of distributed systems in the past three decades. Today, distributed systems, such as the Internet, have become so large that they require highly scalable algorithms; algorithms that have asymptotically-small communication, computation, and latency costs with respect to the network size. Moreover, systems with thousands or even millions of parties distributed throughout the world is likely in danger of faults from untrusted parties.
In this dissertation, we study scalable and secure distributed algorithms that can tolerate faults from untrusted parties. Throughout this work, we balance two important and often conflicting characteristics of distributed protocols: security and efficiency. Our first result is a protocol that solves the MPC problem in polylogarithmic communication and computation cost and is secure against an adversary than can corrupt a third of the parties. We adapted our synchronous MPC protocol to the asynchronous setting when the fraction of the corrupted parties are less than 1/8. Next, we presented a scalable protocol that solves the secret sharing problem between rational parties in polylogarithmic communication and computation cost.
Furthermore, we presented a protocol that can solve the interactive communication problem over a noisy channel when the noise rate in unknown. In this problem, we have focused on the cost of the protocol in the resource-competitive analysis model. Unlike classic models, resource-competitive models consider the cost that the adversary must pay to succeed in corrupting the protocol.National Science FoundationComputer ScienceDoctoralUniversity of New Mexico. Dept. of Computer ScienceSaia, JaredEvans, DavidLuan, ShuangYoung, Maxwel
In Search of the Broad Spectrum Revolution in Paleolithic Southwest Europe [dataset]
No full textSupplementary data for the book:
Jones, E. L. (2016). In Search of the Broad Spectrum Revolution in Paleolithic Southwest Europe (SpringerBriefs in Archaeology). New York: Springer International.
The data are available in both Excel and CSV formats.This dataset includes raw archaeofaunal abundance data and contextual information for assemblages included in compositional meta-analyses reported in the book In Search of the Broad Spectrum Revolution in Paleolithic Southwest Europe. The raw data is reported in the .csv and .xlsx files; the Readme document explains the organization and column headings in the datasheets; and the sources file provides complete reference information for all works cited. Portions of the research reported here were supported by the Graduate School of the University of Washington and the Office of Research at the University of New Mexico, by a Chateaubriand Fellowship from the Mission Scientifique et Technologique of the Embassy of France in the United States, and by the National Science Foundation under Grants No. 947900 and 1148146
Investigation of Infrared Detectors Based on the Gallium-free Superlattice
No full textInfrared detection has proven to be an essential capability in a variety of fields, primarily the medical and defense fields. The current industry standard material is HgCdTe, which has been developing since its inception in the late 1950s.
SLS materials are created from very thin layers, on the order of several to several tens of atomic monolayers, of two different bulk materials. These layers are alternated periodically, which results in entirely new material properties. The most common variety of SLS is the InAs-GaSb SL. This material shows great promise, but has not yet exceeded the performance of MCT detectors. This is due to the fact that the performance of the InAs-GaSb SL is limited by its Shockley-Reed-Hall (SRH) carrier lifetime. A new type of SLS, called the Ga-free SL, has demonstrated a much longer SRH lifetime, and has the potential to exceed the performance of the InAs-GaSb SL.
The focus of this dissertation is the use and optimization of the Ga-free SLS in infrared detectors. This optimization is accomplished though a series of studies that focus on several aspects of growing Ga-free SL-based detectors, including
1. Initial device characterization
2. Doping level in the detector absorber region
3. As:In BEP ratio
4. MMBE-based InAs-InSb vs. ternary InAsSb growth
5. InAs-on-InAsSb interface optimization
The first electrical characterizations of a Ga-free SL detector are reported from the initial device. This device was a MWIR PIN design created from a 14ML InAs - 12ML InAs_{0.65}Sb_{0.35} superlattice. The results of this showed an unexpectedly high level of dark current. The cause of this current was investigated using a curve-fitting program provided by IRNova, which showed that trap-assisted tunneling may be the cause of this result.
The next study compared varied levels of doping in the absorber region of a Ga-free SL MWIR PIN detector. The designs for these devices were similar to the initial device, but the InAsSb composition was changed to be InAs_{0.81}Sb_{0.19}, which provided a better lattice match to the GaSb substrate. The absorber regions were doped at NID (reference), 5x10^{15}, 1x10^{16}, and 3x10^{16} cm^{-3} p-type. P-type doping was chosen to offset the intrinsic n-type behavior of the Ga-free material. The results showed that the highest doping level, at 3x10^{16} cm^{-3}, resulted in the lowest dark current (0.00248 vs. 0.08353 A/cm^{2} for the best device from each sample). The quantum efficiency for this device was slightly reduced from the reference sample, (37.4% vs. 42.4%), as a tradeoff for the reduced dark current levels. The dark current levels of these devices were reduced as the doping increased, thereby indicating G-R dominance.
The BEP ratio study tested several As:In ratios with the purpose of optimizing the growth conditions for an MWIR Ga-free SL. This study performed electrical characterization on three samples with BEP ratios of 5:1, 6:1, and 7:1. These devices were grown using the same MWIR PIN design used in the doping study. Both quantum efficiency and dark current levels from these devices indicated that the 7:1 As:In BEP ratio was an improvement on the lower ratios.
The fourth study discussed in this dissertation compared an MWIR Ga-free SL grown using an MMBE-grown InAs-InSb alloy in place of the InAsSb ternary material with an MWIR Ga-free reference sample. The purpose of this was to determine if the use of the MMBE technique during growth had adverse effects on the electrical performance of the resulting detectors. However, the dark current of the MMBE-based device was lower than the reference sample (0.0853 vs. 0.1227 A/cm^{2} at -10mV bias and 80K), and the quantum efficiency was higher (39.7% vs. 24.1% at -10mV bias and 80K). This indicated that MMBE may improve the resulting devices, rather than detract from their performance.
The final study tested a series of interface layers placed at the InAs-on-InAsSb interface. This was intended to minimize the diffusion of Sb from the InAsSb layer into the following InAs layer. These samples were the same design as used in previous studies, with the exception that the InAsSb layers were all replaced with MMBE InAs-InSb (as tested in the MMBE study). The interface layers tested were a 1 second growth interrupt, a 1 second As soak, a 1 second Al flash, and a 1ML AlSb layer. A reference sample with no special interface layer was also grown. The results showed that the reference, the As soak, and the AlSb layer all showed comparable performance, whereas the Al flash and growth interrupt reduced the quality of the resulting devices. From the resulting data, further study of the use of an As soak is encouraged.U.S. GovernmentElectrical EngineeringDoctoralUniversity of New Mexico. Dept. of Electrical and Computer EngineeringKrishna, SanjayKrishna, SanjayBalakrishnan, GaneshSteenbergen, ElizabethSheik-Bahae, Mansoo
Movement as the Driving Force: Empowering Live Dance Performance Through the Integration of Film
No full textDance and film are two distinct mediums of expression. Movement drives both of
these art forms and is the commonality that serves as the thread that connects them. These
mediums serve as modes of discovery, thinking, and representation. Time and space are
shared components between dance and film. Over the past century, there have been many
different relationships on and off the stage between the two and as a result of this, new
genres like screendance, dance for film, and multimedia performance have emerged. Live
dance performance has been strengthened by the possibilities and uses of multimedia
elements in real time.
After creating the MFA Thesis Concert C’est la Vie | Exquisite Corpse that
correlates with this dissertation, I was left yearning for more knowledge of the medium
and discipline of film. Film expanded the possibilities of time, space, and movement for
the choreographic process and the live dance performance. Therefore, I argue that by
having a deeper understanding of film, live dance performance can be empowered.
Through the experience of creating an evening of live dance integrated with film,
I will explain how these two mediums inform each other in process and product. Even
though dance and film are independent, deeply rooted historical art forms, having a
deeper understanding of the capacity of film presents the opportunity to enhance the
performance on stage. This collaboration creates possibilities that lead to further trans-disciplinary
discourse and an unlimited creative process.DanceDoctoralUniversity of New Mexico. Dept. of Theater and DanceJewell, DonnaSantos Newhall, Mary AnnePredock-Linnell, JenniferHamp, AmandaConde Reche, VladimirGandert, Migue
Cultural Competency in the Dental Hygiene Curricula: A Survey
No full textAs the population of the nation becomes more diverse, dental hygiene programs must ensure graduates are receiving cultural competency training in entry-level educational programs. The purpose of this study was to establish a baseline for what topics of cultural competency training are or are not being incorporated into dental hygiene schools and to determine if differences exist between topics covered amongst the types of degree-granting institutions. Topics were investigated via survey instrument and data was collected from 76 U.S dental hygiene program directors. Results of this study emphasized the similarities between entry-level dental hygiene programs and illustrated a lack of difference between topics of cultural competency training taught between associate and baccalaureate-granting dental hygiene institutions. More effort must be made by all entry-level degree granting dental hygiene program to ensure cultural competency training is implemented.Dental HygieneMastersUniversity of New Mexico. Division of Dental HygieneNathe, ChristineAboytes, Dian
THE EFFECT OF RELATIVE ELECTRODE SIZE ON THE PERFORMANCE OF A SUPERCAPACITIVE MICROBIAL FUEL CELL DESIGN
No full textSupercapacitive microbial fuel cells with various anode and cathode dimensions were investigated in order to determine the effect on capacitance and delivered power quality. The cathode size was determined to be the limiting component of the system, while anode size showed little effect on the device’s performance. By doubling the cathode area, peak power output was improved by roughly 120% for a 10 ms pulse discharge. Doubling the cathode area also had a positive effect on the internal resistance of the cell, lowering the equivalent series resistance by approximately 47%. Doubling the anode area increased peak power output slightly, with an 11% increase in peak power output observed. A model was constructed in order to predict the performance of a hypothetical cylindrical MFC design with larger relative cathode size. The analysis predicts that a small device based on conventional materials with a volume of approximately 21 cm3 would be capable of delivering a peak power output of approximately 76 mW at 190 mA, or ~1200 W/m3Bill & Melinda Gates FoundationNanoscience & Microsystems EngineeringMastersUniversity of New Mexico. Nanoscience and Microsystems ProgramAtanassov, PlamenSantoro, CarloCerrato, Jos
THE IMPACT OF A THEORY-BASED WEB INTERVENTION ON THE INTENTION TO USE PRESCRIPTION DRUGS FOR NON-MEDICAL PURPOSES AMONG COLLEGE STUDENTS: A RANDOMIZED CONTROLLED TRIAL
No full textThe nonmedical use of prescription drugs (NMUPD) among college students is escalating at an alarming rate. A limited number of studies have utilized a theoretical framework to understand and change this behavior. The main objectives for this study were (1) to utilize the reasoned action approach (theoretical framework) to design and evaluate an intervention to change students’ intentions toward NMUPD, and (2) to test the predictive validity of the reasoned action approach in understanding NMUPD.
Methods: The intervention was designed and tested during a pilot phase. Using a two-group post-test controlled trial, students were randomly assigned to either the intervention group or the control groups. The numbers of respondents in the intervention group were 188, and in the control group were 199. A survey was conducted to test the effectiveness of the intervention and the predictive validity of the reasoned action approach in understanding NMUPD
Results: Overall, college students have strong intentions to avoid NMUPD. They also have negative attitudes toward NMUPD, high perceived norms that their important referents will not approve their NMUPD, and high perception that NMUPD is under their control. The intervention was able to bring changes in attitudes between the intervention and control groups. However, no changes were observed in intentions, perceived norms, perceived behavioral control, nor in their underlying beliefs. The reasoned action approach major constructs (attitudes, norms, and perceived behavioral control) were successful in explaining 37% of the variance in students’ intentions to avoid NMUPD. The most significant predictor of students’ intentions was perceived norms. The demographic factors that were significantly associated with intentions to avoid NMUPD included previous NMUPD, gender, tobacco use, marijuana use, and alcohol consumption. An analysis restricted to only those who reported NMUPD, showed that students who used stimulants have lower intentions to avoid NMUPD, more favorable attitudes toward NMUPD, but lower perceived norms that their important referents will not approve their NMUPD.
Conclusion: The reasoned action approach was successful in predicting students’ intentions to avoid NMUPD, though the theory-based intervention was less successful in influencing and changing these intentions. More research is needed to improve the intervention dissemination and utilization. Future interventions should focus on both reducing the perceived social pressure and the approval of NMUPD, in addition to changing favorable attitudes toward NMUPD into unfavorable attitudes, especially among stimulants users.Pharmaceutical SciencesDoctoralUniversity of New Mexico. College of PharmacyRaisch, DennisBorrego, MatthewHamidovic, AjnaSleath, Bets
The Framework for Information Literacy: Academic Librarians' Perceptions of Its Potential Impact on Higher Education Library Praxes
No full textThe Framework for Information Literacy for Higher Education ("the Framework") may serve to influence academic library praxes. A total of 138 academic librarian participants were randomly selected (32 deans and 106 non-deans) from public and private institutions. The institutions spanned across six accrediting regions recognized by the Council for Higher Education Accreditation. Participants completed a 22-item survey designed to elicit their perceptions of the Framework's impact. Professional position (deans or non-deans) was significantly correlated with the perceived level of impact that the Framework might have on library praxes. That is, deans tended to rate the Framework at a higher level of impact than non-deans. The final question on the survey was open-ended, asking participants to explain their rating of overall impact the Framework may have on library practices at their institutions. Qualitative coding of responses to the final question revealed three themes indicating advantages of the Framework, and twelve themes indicating challenges of the Framework. Findings from this study may be useful to academic librarians, discipline faculty, and other institutional stakeholders in determining how information literacy instruction is defined, promoted, and taught in higher education. Findings may also serve to initiate and illuminate conversations around the Framework, and how to approach possible implementation.Organization, Information & Learning SciencesDoctoralUniversity of New Mexico. Division of Educational Leadership and Organizational LearningBoverie, PatriciaWilkinson, FrancesGreen, AlisonEmmons, Mar
Enhanced Laminar Convective Heat Transfer using Microstructured Superhydrophobic Surfaces
No full textFor many centuries, researchers have investigated the complex interactions between a solid surface and a fluid in motion relative to the surface. For many cases, the classical no slip boundary condition holds true. However, there are a subset of situations where this assumption is not valid, and slip between the surface and fluid must be considered. One such example is a micropatterned, superhydrophobic surface, which has been shown to enable slip resulting in a decrease in drag and pressure loss for both laminar and turbulent flow. The hydrodynamic effects of these surfaces have been studied in depth, but the effects on heat transfer are largely unknown. The primary goal of this research effort was to explore the effects of slip flow on laminar convective heat transfer resulting from micropatterned, superhydrophobic surfaces.
The first step toward achieving the research goal was to develop a model to study first order effects, predict the effect of slip flow on heat transfer, and design the experimental setup. The general momentum equation for Poiseuille flow was solved using modified boundary conditions consistent with slip flow, and the resulting velocity profile was input into the thermal balance equation which was numerically solved. The model assumed hydrodynamic slip but not thermal slip nor a temperature jump at the boundary, and as a result, it predicted a net increase in heat transfer performance.
For the experimental portion of the study, laminar Poiseuille flow in a parallel plate configuration with a constant temperature boundary condition at 273 K using an ice bath was studied. Four sets of copper sample plates measuring 15 cm by 3.8 cm were fabricated with different surface condition: 1) uncoated smooth, 2) hydrophobic coated smooth, 3) uncoated micropatterned, and 4) hydrophobic coated micropatterned. The micropattern was a laser machined array of 25 m x 25 m microridges oriented in the streamwise direction. Contact angle measurements were made on all of the test samples to ensure the coated plates were hydrophobic and the uncoated plates were not.
From the experimental results, several observations and conclusions were made. First, only the micropatterned, superhydrophobic coated sample achieved a slip state with an average slip length of 0.3 mm. Second, hydrodynamic slip was observed without the accompaniment of thermal slip since the heat transfer performance for the superhydrophobic sample was as good as or better than the baseline sample for all flow rates tested. Finally, it was concluded that micropatterned superhydrophobic surfaces reduce pressure loss and improve heat transfer as seen by the improved efficiency factor, which is the ratio between the Nusselt number and the friction loss.EngineeringDoctoralUniversity of New Mexico. Dept. of Mechanical EngineeringVorobieff, PeterTruman, C. RandallPetsev, Dimitervan Swol, FrankMammoli, Andre