Browsing by Subject "Mobility"
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Item Assessment of boar sperm samples by computer-assisted sperm anaylsis and the mobility assay(2007-05) Tilley, Breanna; Vizcarra, Jorge A.; Alvarado, Christine Z.; Glayean, MichealThe sperm mobility assay (Accudenz) used in the present study measures sperm penetration into a biologically inert gradient solution. When a sample of sperm is overlaid in a cuvette containing Accudenz, sperm penetrate the solution and then measured with a spectrophotometer. The mobility assay has been successfully used to select chicken and turkey sperm donors. We validated this assay for semen from boars. Absorbance was measured after overlaying stored semen (24h) from each boar in prefilled cuvettes for 1, 5, 10, 15, 20, 40 min. There were no significant differences between sperm concentrations 1 x 108 and 5 x 107 viable sperm/mL. Absorbance was half-maximal at 13.1 min. In addition, there was medium repeatability for individual boars. There were positive correlations between mobility values and several computer-assisted sperm analysis (CASA) measurements, and low to high reproducibility for several CASA measurements. We concluded that further study is needed to find the proper Km and, the mobility and CASA measurements are correlated.Item Demonstration of decision support tools for evaluating ground combat system survivability, lethality, and mobility at the tactical, operational, and strategic levels of war(2011-08) Keena, Joshua Monroe; Moon, T. J. (Tess J.); Campbell, Matthew I.; Fahrenthold, Eric P.; Fair, Harry D.; Funk, Paul E.; Howell, John R.Decision makers often present military researchers with a most daunting challenge: to pursue, with some level of prophetic certainty, innovative concepts that will yield increased capabilities during future wars against forecasted threats in not-yet- determined locations. This conundrum is complicated further with the requirement that the proposed technology yield benefit throughout the various strata of military operations. In the maturation of an advanced capability enabled by a technological advancement, a groundbreaking design should simultaneously demonstrate performance overmatch against an envisioned foe while showing that the costs associated with development, procurement, and operation outweigh reverting to an incremental advancement in the conventional means of delivering combat power. This manuscript focuses on the construction and utilization of decision support tools for use by scientists and engineers charged with providing a quantitative evaluation of an advanced ground combat system. The concepts presented focus on the effects and synergy regarding the combat vehicle principal attributes of survivability, lethality, and mobility. Additionally, this study provides a framework for analysis of these attributes when screened at the tactical, operational, and strategic levels of war. These concepts are presented and demonstrated from both the candidate selection (or choice) perspective, and the concept development (or design) perspective. As an example of this approach, this study includes a comparison of conventional powder gun cannonry versus a specific type of electromagnetic launch device known as the railgun. The decision support tools formulated in this dissertation allow the user to distill, at a coarse level of fidelity, the parametric relationships between system survivability, lethality, and mobility for advanced weapon system concepts. The proposed methods are suited for evaluation at the nascent stages of development, when the information normally applied in standard methods is sparse. This general approach may also be valuable in contemporary acquisition strategies employed in urgent fielding efforts, where the immediacy of the problem can benefit from an expedient and efficient method of analyzing the coupled and synergistic effects of implementing a proposed technology. While advantage is typically measured in terms of performance overmatch at the platform level, the broadening of this consideration vertically to higher levels of military command can aid in identifying the competing issues and complementary relationships related to a technical approach. Finally, given the backdrop demonstration for the framework, this manuscript may serve as a brief summary of system fundamentals and design theory for direct fire powder gun cannonry and electromagnetic railguns.Item Device physics and device mechanics for flexible MoS2 thin film transistors(2015-08) Chang, Ph. D., Hsiao-Yu; Akinwande, Deji; Lu, Nanshu; Lee, Jack; Lai, Keji; Dodabalapur, AnanthWhile there has been increasing studies of MoS2 and other two-dimensional (2D) semiconducting dichalcogenides on hard conventional substrates, experimental or analytical studies on flexible substrates has been very limited so far, even though these 2D crystals are understood to have greater prospects for flexible smart systems. In the first part, we report detailed studies of MoS2 transistors on industrial plastic sheets. Failure mechanisms under strain are studied with bending test and stretching test. Experimental investigation identifies that crack formation in the dielectric and the buckling delamination in MoS2 are responsible for the degradation of the device performance. Several approaches to improve device flexibility were discussed. In the second part, electronic transport properties in multilayer MoS2 are investigated with Y-function method. By combining experiments and analysis, we show that the Y-function method offers a robust route for evaluating the low-field mobility, threshold voltage and contact resistance even when the contact is a Schottky-barrier as is common in two-dimensional transistors. In addition, an independent transfer length method (TLM) evaluation corroborates the modified Y-function analysis. The last part, we demonstrate the first RF performance for transferred CVD-grown MoS2 FETs on the flexible substrate. Our result suggests that the large-area CVD-grown MoS2 provides a practical route to realize low-power, high speed electronics circuit applications in the future.Item Discharge gait speed and hospital readmission for the elderly population: A pilot study(2015-06-02) Martinez, Gabriela E.; Lawson, Kayla; Braden, HeatherABSTRACT Objective: To describe whether discharge gait speed, after a course of physical therapy, is related to hospital readmission in the elderly population. Design: Observational cross-sectional study of discharge gait speed and a tracking system linking those who were readmitted to the hospital in 3 and 6 months post-discharge. Setting: Acute care, skilled nursing, and inpatient rehabilitation facilities of a regional medical center in the United States. Participants: Individuals (N=172) that were admitted with physical therapy orders with full weight bearing status who could ambulate 20 feet and consented to participate. Participants who had orthopedic or neurologic primary diagnoses or elective surgeries were excluded. Participants were contacted at home at 3 month and 6 months after inpatient stays to determine subsequent readmissions to any inpatient facility. Main Outcome Measure: Discharge gait speed and 3 and 6 month inpatient readmission. Results: Participants who required readmission to an inpatient setting had discharge gait speed of 0.44 m/s Ā±0.08 (N=12) while those not readmitted had a discharge gait speed of 0.52 m/s Ā±0.10 (N=23). Independent t-tests failed to show significant differences in the two speeds with the limited participant size. Conclusions: Although significant differences in discharge gait speed were not realized in this small pilot study, discharge gait speed has the potential to be an informative measure of patient status after initial inpatient stay, given the appropriate statistical power. This is a pilot study that requires additional data collection (N=318) to obtain a power of 80% with the possibility of realized differences in the two groups.Item Exploiting temporal stability and low-rank structure for localization in mobile networks(2010-08) Rallapalli, Swati; Zhang, Yin, doctor of computer science; Qiu, Lili, Ph. D.Localization is a fundamental operation for many wireless networks. While GPS is widely used for location determination, it is unavailable in many environments either due to its high cost or the lack of line of sight to the satellites (e.g., indoors, under the ground, or in a downtown canyon). The limitations of GPS have motivated researchers to develop many localization schemes to infer locations based on measured wireless signals. However, most of these existing schemes focus on localization in static wireless networks. As many wireless networks are mobile (e.g., mobile sensor networks, disaster recovery networks, and vehicular networks), we focus on localization in mobile networks in this thesis. We analyze real mobility traces and find that they exhibit temporal stability and low-rank structure. Motivated by this observation, we develop three novel localization schemes to accurately determine locations in mobile networks: 1. Low Rank based Localization (LRL), which exploits the low-rank structure in mobility. 2. Temporal Stability based Localization (TSL), which leverages the temporal stability. 3. Temporal Stability and Low Rank based Localization (TSLRL), which incorporates both the temporal stability and the low-rank structure. These localization schemes are general and can leverage either mere connectivity (i.e., range-free localization) or distance estimation between neighbors (i.e., range-based localization). Using extensive simulations and testbed experiments, we show that our new schemes significantly outperform state-of-the-art localization schemes under a wide range of scenarios and are robust to measurement errors.Item From disease to desire : Panama and the rise of the Caribbean vacation(2016-05) Scott, Blake Charles; Guridy, Frank Andre; Garrard-Burnett, Virginia; Lawrence, Mark Atwood; Raby, Megan; Sutter, Paul S.This dissertation traces the historical ārootsā and āroutesā of a transnational tourism industry stretching from the Straits of Florida to the Isthmus of Panama. The project describes the emergence of a quintessential āCaribbean vacationā and critically examines ideas and social practices guiding U.S. travelers comfortably into the tropics. Focusing on historical linkages embedded in a key trade route ā coalescing at the Isthmus of Panama ā the dissertation shows how leisure travel reshaped the history of U.S.-Caribbean relations. The building of the Panama Canal between 1904 and 1914 marked a profound shift in U.S. traveling culture. Modern tourism emerged within the crucible of U.S. empire building and its associated cultural, scientific, and infrastructural developments. My research documents this history through the stories of a wide range of travelers who helped shape and define the Caribbeanās tourism industry. By paying close attention to specific cases of mobility and sometimes immobility, the dissertation analyzes broader trends that still effect the tourist experience. Chapters highlight the stories of U.S. frontiersmen who became tourist entrepreneurs in the early twentieth century; national elites in Panama and Cuba who turned liberal aspirations of progress and desirable immigration into tourism development; naturalists and explorers from the Smithsonian who produced knowledge not only for science but also for tourists in search of adventure and discovery in exotic lands; and traveling writers from the āLost Generationā who articulated new motivations and means of escape for folks at home tired of the drudgery of modern life. These diverse social groups have rarely, if ever, been analyzed in relation to the Caribbeanās modern tourism industry. Their ideas and their travels, I show, influenced the way generations of tourists dreamed of and experienced the Caribbean.Item The impact of weightsā specifications with the multiple membership random effects model(2015-05) Galindo, Jennifer Lynn; Beretvas, Susan Natasha; Whittaker, Tiffany; Pituch, Keenan; Dodd, Barbara; Hersh, MatthewThe purpose of the simulation was to assess the impact of weight pattern assignment when using the multiple membership random effects model (MMREM). In contrast with most previous methodological research using the MMREM, mobility was not randomly assigned; rather the likelihood of student mobility was generated as a function of the student predictor. Two true weights patterns were used to generate the data (random equal and random unequal). For each set of generated data, the true correct weights and two incorrect fixed weight patterns (fixed equal and fixed unequal) that are similar to those used in practice by applied researchers were used to estimate the model. Several design factors were manipulated including the percent mobility, the ICC, and the true generating values of the level one and level two mobility predictors. To assess parameter recovery, relative parameter bias was calculated for the fixed effects and random effects variance components. Standard error (SE) bias was also calculated for the standard errors estimated for each fixed effect. Substantial relative parameter bias differences between weight patterns used were observed for the level two school mobility predictor across conditions as well as the level two random effects variance component, in some conditions. Substantial SE bias differences between weight patterns used were also found for the school mobility predictor in some conditions. Substantial SE and parameter bias was found for some parameters for which it was not anticipated. The results, discussion, future directions for research, and implications for applied researchers are discussed.Item Investigation of charge transport in organic photovoltaic materials using lateral device structures(2016-08) Slobodyan, Oleksiy Viktor; Dodabalapur, Ananth, 1963-; Bank, Seth; Vanden Bout, David; Yu, Edward; Wang, ZhengUnderstanding of charge carrier transport and recombination in bulk heterojunction (BHJ) materials is important for continued improvement of organic photovoltaics (OPVs). Solar cell efficiencies now approach 12% and answers to lingering questions create a roadmap for increasing this value. OPVs are made as vertical structures and majority of analyses in literature are directed to this structure. In this dissertation, theoretical and experimental analyses of lateral devices are developed to compliment the knowledge base established with vertical devices. Lateral OPVs offer unique insights into transport and recombination physics in BHJs: they decouple charge extraction from charge photogeneration, allow clear formation of space-charge regions and recombination zone, open the BHJ to probing, and allow comparison of ambipolar to unipolar electron & hole currents. Lateral OPVs are simulated to understand their current-voltage behavior and link it to development of space-charge. Modeling focuses on the intermediate 3um channel length. At this transport length effects of space-charge behavior are clearly present and all photogenerated charge can be extracted. Modeling work is used to support analysis of experimental results. BHJs made of electron-transporter [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and hole transporting polymer poly[3-hexylthiophene-2,5-diyl] (P3HT) and co-polymer poly[2-(5-(4,4-dioctyl-4H-silolo[3,2-b:4,5-bā]dithiophen-2-yl)-3-tetradecylthiophen-2-yl)-5-(3-tetradecylthiophen-2-yl)thiazolo[5,4-d]thiazole] (PDTSi-TzTz) are studied. Transport in PDTSi-TzTz:PCBM is analyzed by profiling the channel potential. The channel potential and current-voltage measurements are used to obtain carrier mobilities and recombination rates. High charge collection efficiency is found even at transport lengths greater than 1 micron. Photocurrent and extracted unipolar injection currents in P3HT:PCBM blends are studied. These measurements yield intensity-dependent mobilities of both electrons and holes. Extraction of both mobility values in the same BHJ point to electron mobility as the limiting factor in OPV performance.Item Mechanical stress and circuit aging aware VLSI CAD(2010-12) Chakraborty, Ashutosh; Pan, David Z.; Abraham, Jacob; Orshansky, Michael; Saxena, Prashant; Touba, NurWith the gradual advance of the state-of-the-art VLSI manufacturing technology into the sub-45nm regime, engineering a reliable, high performance VLSI chip with economically attractive yield in accordance with Moore's law of scaling and integration has become extremely difficult. Some of the most serious challenges that make this task difficult are: a) the delay of a transistor is strongly dependent on process induced mechanical stress around it, b) the reliability of devices is affected by several aging mechanisms like Negative Bias Temperature Instability (NBTI), hot carrier injection (HCI), etc and c) the delay and reliability of any device are strongly related to lithographically drawn geometry of various features on wafer. These three challenges are the main focus of this dissertation. High performance fabrication processes routinely use embedded silicon-germanium (eSiGe) technology that imparts compressive mechanical stress to PMOS devices. In this work, cell level timing models considering flexibility to modulate active area to change mechanical stress, were proposed and exploited to perform timing optimization during circuit placement phase. Analysis of key physical synthesis optimization steps such as gate sizing and repeater insertion was done to understand and exploit mechanical stress to significantly improve delay of interconnect and device dominated circuits. Regarding circuit reliability, the proposed work is focused on reducing the clock skew degradation due to NBTI effect specially due to the use of clock gating technique for achieving low power operation. In addition, we also target the detrimental impact of burn-in testing on NBTI. The problem is identified and a runtime technique to reduce clock skew increase was proposed. For designs with predictable clock gating activities, a zero overhead design time technique was proposed to reduce clock skew increase over time. The concept of using minimum degradation input vector during static burn-in testing is proposed to reduce the impact of burn-in testing on parametric yield. Delay and reliability strongly depend on dimension of various features on the wafer such as gate oxide thickness, channel length and contact position. Increased variability of these dimensions can severely restrict ability to analyze or optimize a design considering mechanical stress and circuit reliability. One key technique to control physical variability is to move towards regular fabrics. However, to make implementation on regular fabrics attractive, high quality physical design tools need to be developed. This dissertation proposes a new circuit placement algorithm to place a design on a structured ASIC platform with strict site and clock constraints and excellent overall wirelength. An algorithm for reducing the clock and leakage power dissipation of a structured ASIC by reducing spine usage is then proposed to allow lower power dissipation of designs implemented using structured ASICs.Item Mobile computing in a clouded environment(2009-12) Rosales, Jacob Jason; Julien, Christine; Bard, WilliamCloud Computing has started to become a viable option for computing centers and mobile consumers seeking to reduce cost overhead, power consumption, and increase software services available within their platform. For instance distributed memory constrained mobile devices can expand their ability to share real time data by utilizing virtual memory located within the cloud. Cloud memory services can be configured to restrict read and write access to the shared memory pool on a partner by partner basis. Utilization of such resources in turn reduces hardware requirements on mobile devices while lessening power consumption for each physical resource. Within the Cloud Computing paradigm, computing resources are provisioned to consumers on demand and guaranteed through service level agreements. Although the idea of a computing utility is not new, its realization has come to pass as researchers and corporate companies embark on a journey of implementing highly scalable cloud environments. As new solutions and architectures are proposed, additional use cases and consumer concerns have been revealed. These issues range from consumer security, adequate service level agreements and vendor interoperability, to cloud technology standardizations. Further, the current state of the art does not adequately address these needs for mobile consumers, where services need to be guaranteed even as consumers dynamically change locations. Due to the rapid adoption of virtualization stacks and the dramatic increase of mobile computing devices, cloud providers must be able to handle logical and physical mobility of consumers. As consumers move throughout geographical regions, there exists the probability that a consumerās new locale may hinder a producerās ability to uphold service level agreements. This inability is due to the fact that a producer may not have physical resources located relatively close to a mobile consumerās new locale. As a consequence, producers must either continue to provide degraded resource consumption or migrate workloads to third party producers in order to ensure service level agreements are maintained. The goal of this report is to research existing architectures that provide the ability to adequately uphold service level agreements as mobile consumers move from locale to locale. Further we propose an architecture that can be implemented along with existing solutions in order to ensure consumers receive adequate service levels regardless of locality. We believe this architecture will lead to increased cloud interoperability and decreased consumer to producer platform coupling.Item MOBILITY AND STUDENT ACHIEVEMENT IN TEXAS: A MULTIYEAR, STATEWIDE INVESTIGATION(2016-08-04) Bostick, Benjamin Mark; Slate, John R.; Martinez-Garcia, Cynthia; Moore, George W.Purpose The first purpose of this journal-ready dissertation was to investigate the relationship of mobility to student achievement in Grade 6 students when controlling for economic status and not controlling for economic status. The second purpose was to examine the relationship of mobility to Grade 7 studentsā academic achievement when controlling for and not controlling for economic status. Finally, the third purpose was to examine the relationship of mobility to the academic achievement of Grade 8 students when controlling for and not controlling for economic achievement. Method A non-experimental research design was used in this study. Participants were selected from the Texas Education Agency Public Education Information Management System. This database is publicly accessible and contains archival data about studentsā enrollment, demographic, and testing history. Archival data were obtained for the 2002-2003, 2003-2004, 2004-2005, 2005-2006, 2006-2007, and 2007-2008 school years for Grade 6, 7, and 8 students in an accountability subset for a campus or district. Raw scores from the Texas Assessment of Knowledge and Skills Reading, Mathematics, Science, and Writing tests were analyzed to determine if mobility, as measured by a student being enrolled at a campus less than 83% of the school year, had an effect on academic achievement, and if that effect persisted when controlling for economic status. ā Findings Results were consistent across all three grade levels and all subject areas. Statistically significant results were present for all analyses when controlling for and not controlling for economic status. Effect sizes for the relationship between economic status and academic achievement were large. Effect sizes for the relationship between mobility and academic achievement were trivial when controlling for and not controlling for economic status. Average scores for mobile students were between 1.93 and 3.69 points lower than the average scores of non-mobile students in reading; 2.57 and 5.63 points lower than the average scores of non-mobile students in mathematics; 1.66 and 2.42 points lower than the average scores of non-mobile students in writing; and 4.65 to 5.02 points lower than the average scores of non-mobile students in science. As such, results were congruent with the extant literature.Item Natural Organic Matter (NOM) in Aquatic Systems: Interactions with Radionuclides (234Th (IV), 129 I) and Biofilms(2011-10-21) Zhang, SaijinA series of laboratory and field investigations were carried out to elucidate the importance of natural organic matter in aquatic systems, i.e., trace element scavenging (e.g., 234Th) by exopolymeric substances (EPS), formation of biofilms, as well as interactions with 129I. A method involving cross flow ultrafiltration, followed by a three-step cartridge soaking and stirred-cell diafiltration, was developed for isolating EPS from phytoplankton cultures, especially in seawater media. EPS isolated from a marine diatom, Amphora sp. was then subjected to semi-quantitative (e.g., carbohydrate, proteins) and quantitative analysis (e.g., neutral sugars, acidic sugars, sulfate). It appeared that Th (IV) binding by EPS was dominated by the acidic polysaccharides of fraction. For EPS of biofilms collected from polluted streams, hydrophobic proteins were the most abundant components in EPS, followed by more hydrophilic carbohydrates. However, chemical composition of carbohydrates or proteins, i.e., monosaccharides and amino acids, respectively, varied with environmental conditions and substrata applied, which suggests that the formation of biofilms on different substrates is regulated by specific properties of microorganisms, environmental conditions and nature of substratum. No correlation between relative hydrophobicity of substratum and development of biofilm was found in this study. A sensitive and rapid GC-MS method was developed to enable the determination of isotopic ratios (129I/127I) of speciated iodine in natural waters. At the F-area of the Savannah River Site (SRS), iodine species in the groundwater consisted of 48.8 percent iodide, 27.3 percent iodate and 23.9 percent organo-iodine. Each of these iodine species exhibited vastly different transport behavior in the column experiments using surface soil from the SRS. Results demonstrated that mobility of iodine species depended greatly on the iodine concentration, mostly due to the limited sorptive capacity for anions of the soil. EPS, especially enzymes (e.g., haloperoxidases) could facilitate the incorporation of iodide to natural organic carbon. At high input concentrations of iodate (78.7 ?M), iodate was found to be completely reduced and subsequently followed the transport behavior of iodide. The marked reduction of iodate was probably associated with natural organic carbon and facilitated by bacteria, besides inorganic reductants (e.g., Fe2 ) in sediments and pore water.Item Practices of place : ordinary mobilities and everyday technology(2016-05) Gaughen, Brendan Christopher; Meikle, Jeffrey L., 1949-; Hoelscher, Steven; Adams, Paul; Strover, Sharon; Campbell, CraigThis study examines four distinct ways people have encountered and interacted with place and explores how these experiences are impacted by certain technologies, paying close attention to the human experience of mobility. A fundamental idea in this study is that mobility is a crucial component to human identity and it is too limiting to view mobility as an abstraction absent of lived experience, as many postmodern theorists have done. Viewing mobility as an interrelation between people, place, and technology that shapes human beings and the physical environment, this study seeks to show how certain interactions with place contribute to a sense of self and identity for the individuals and communities discussed therein. The primary attempt in this study is to demonstrate how and why place is used in different ways by different people through various acts of mobility. Many of these practices, I believe, emerge as a response to postmodernity, even if their participants are unaware of larger structural processes. These practices are attempts to create stable meanings, definitions, and identities, to make known the unknown, to provide people with a sense of agency and autonomy, and give aspects of permanence to the ephemeral all in order to resist the destabilization, uncertainty, and powerlessness that exist in the present. Employing strategies such as bricolage and poetics, the human actors described in this study employ various practices of place in order to create meaning for themselves and the places they inhabit. This interdisciplinary project contributes to discourses of human geography, digital humanities, and material culture by locating previously unexplored intersections and relationships between place, practice, mobility, technology, and the human experience of being in place.Item Reframing Harlem River : Manhattan-Bronx waterfront community design(2014) Yang, Sheng, M. of Architecture; Almy, Dean; Alter, KevinToday a renewed interest in the recreational value of the Harlem River, paired with new real estate pressures that are reshaping East Harlem and the Southern portion of the Bronx, the moment is ripe to rethink the current scalar incongruence between city, mobility corridors and the water edge. Both in the case of Manhattan and the Bronx the expansive geometries of the mobility infrastructure has inscribed, along both edges, a physical and operative footprint that is at odds with the scale of the water's edge and the city. This design is to propose an idea to renovate Harlem waterfront area into interactive and livable place in the densely populated city. The first point is to accommodate a number of people with enough housing units, and then hopefully this area could be a catalyst to increase vitality of nearby area. This is a mixed-use area that includes commercial, residences, offices, athletics and recreations, and a pedestrian bridge connecting to Manhattan.Item Retrospect on contemporary Internet organization and its challenges in the future(2011-05) Gutierrez De Lara, Felipe; Bard, William Carl, 1944-; Julien, ChristineThe intent of this report is to expose the audience to the contemporary organization of the Internet and to highlight the challenges it has to deal with in the future as well as the current efforts being made to overcome such threats. This report aims to build a frame of reference for how the Internet is currently structured and how the different layers interact together to make it possible for the Internet to exist as we know it. Additionally, the report explores the challenges the current Internet architecture design is facing, the reasons why these challenges are arising, and the multiple efforts taking place to keep the Internet working. In order to reach these objectives I visited multiple sites of organizations whose only reason for existence is to support the Internet and keep it functioning. The approach used to write this report was to research the topic by accessing multiple technical papers extracted from the IEEE database and network conferences reviews and to analyze and expose their findings. This report utilizes this vii information to elaborate on how network engineers are handling the challenges of keeping the Internet functional while supporting dynamic requirements. This report exposes the challenges the Internet is facing with scalability, the existence of debugging tools, security, mobility, reliability, and quality of service. It is explained in brief how each of these challenges are affecting the Internet and the strategies in place to vanquish them. The final objectives are to inform the reader of how the Internet is working with a set of ever changing and growing requirements, give an overview of the multiple institutions dedicated to reinforcing the Internet and provide a list of current challenges and the actions being taken to overcome them.Item Ride to live, live to ride : motorcycle dispatches from MaceiĆ³(2015-05) Layton, Katherine Alice; Leu, Lorraine; Ali, Kamran ATraffic codes and highways exist as powerful tools of measurement and coding by the State that attempt to regulate and control the mobility of bodies through space. In Brazil, these measures and codes function according to capitalist hierarchies of commodities, social practices of exclusion that severely debilitate the mobility of all but a few, and the colonial histories upon which these were constructed. This thesis examines such processes at work in the use of motorcycles as a form of transport for low and low-middle income social groups in an urban setting in the Northeast of Brazil. The simplistic categorization of motorcycles as dangerous, a hackneyed explanation for the high number of accidents and fatalities involving motorcycles in Brazil, reveals exclusion and colonial power at work. This thesis aims to explore the presumption and inscription of motorcycles and their riders as inherently dangerous or threatening actors in order to answer the deceptively simple question: why are motorcycles considered hazardous?Item The road less traveled : forms of mobility in The motorcycle diaries(2012-05) Mills, Brian Scott; Zonn, Leo; Adams, Paul C.; Ramirez Berg, CharlesThe Road Less Traveled is about engaging film from a geographic perspective, specifically analyzing the underlying structures, cultural contexts and forces affecting the movements of the two main protagonists of the film The Motorcycle Diaries. The focus at the individual scale aims to reveal not just how and where, but why people chose to move where they do. The paper is divided into five main chapters: mobility as resistance, mobility as structured process in the form of motility and moorings, forced mobility as distinctive from chosen mobility, mobility as discovery and a final body chapter that demonstrates examples of all these types of mobility. These sections will mainly flow as neoformal, mostly chronologic descriptions of the film text, but will also occasionally reference the written text of the two diaries on which the movie is based. While the main character of the film is Che Guevara, no attention will be dedicated to his revolutionary life outside of the time frame encompassed by the film.Item Spatially explicit, individual-based modelling of pastoralists' mobility in the rangelands of east Africa(Texas A&M University, 2005-11-01) MacOpiyo, Laban AderoAn agent based-model of mobility of pastoralists was developed and applied to the semi-arid rangeland region extending from southern Ethiopia to northern Kenya. This model was used to investigate temporal adaptation of pastoralists to the spatial heterogeneity of their environment. This dissertation describes the development, structure, and corroboration process of the simulation model, Pastoral Livestock Movement Model (PLMMO). PLMMO is a spatially explicit, individual-based pastoralists-animal foraging and movement model. It simultaneously simulates the foraging and movement behavior of individual pastoralists and their livestock in a rangeland ecosystem. Pastoralists?? herd mobility patterns and other measures of movement were compared to data from field studies. Predictions of the model correspond to observed mobility patterns across seasons. The distances moved were found to be significantly correlated (r2 = 0.927 to 0.977, p<0.0001) to drought and non-drought climatic regimes. The PLMMO model therefore proved to be a useful tool for simulating general movement patterns of pastoralists relative to movement range sizes in the pastoral rangelands of southern Ethiopia and northern Kenya. We then used the PLMMO model to explore the impact of emerging changes in rangeland use in the study area. The ways in which pastoralists?? mobility patterns adapt to emerging challenges in the study area were explored by simulating the following four scenarios: 1) climate change with concomitant reduction in forage yield, 2) climate change with concomitant improvement and higher variability in forage yield, 3) increased livestock population densities and 4) improved access to water. The climate induced change scenario with increased and more variable forage production resulted in the shortest distances moved by pastoralists in comparison to all other scenarios. The total search distances under this scenario were only 20% of normal season distances. The improved water access scenario also returned a significant (p=0.017) drop in distances moved. There was, however, no significant impact on either increase in livestock numbers or reduction in available forage on mobility. We judged the agent-based model PLMMO developed here as a robust system for emulating pastoral mobility in the rangelands of eastern Africa and for exploring the consequences of climate change and adaptive management scenarios.