92 research outputs found

    Emotional and attitudinal responses to remote versus co-located usability testing

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    Current usability testing is often conducted via face-to-face interactions. This method can be costly, both in terms of timelines and budget. However, remote usability testing has been shown to be a viable alternative, in that performance scores have been shown to be quite similar to face-to-face methods. Although performance appears similar, remote usability testing may present challenges that threaten the validity and reliability of usability testing results. Rather than focusing on the performance of users in remote versus co-located conditions, the proposed study investigates the emotional and attitudinal responses of users engaged in software usability tests. The purpose of this study was to compare users’ anxiety and satisfaction with communication in remote and face-to-face usability tests. It was hypothesized that participants in the remote condition would exhibit a lower level of anxiety and be less satisfied with the communication method. Multiple usability tasks were administered and measures were recorded at three time intervals. Responses on the Social Anxiety Thoughts (SAT) questionnaire and the Communication Satisfaction Inventory (CSI) were collected. Although there were no significant differences between the groups in terms of anxiety and communication satisfaction, methodological limitations may have prevented the detection of differences and additional research is required to explore the strengths and weaknesses of remote usability testing

    An investigation of the accuracy of pressure measurements and pressure interpolation on the roof of a low-rise building

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    With three of the largest metropolitan areas in the United States along the Gulf coast (Houston, Tampa, and New Orleans), residential populations ever increasing due to the subtropical climate, and insured land value along the coast from Texas to the Florida panhandle greater than $500 billion, hurricane related knowledge is as important now as ever before. This report focuses on model-scale low-rise building wind tunnel tests done in connection with full-scale low-rise building tests. Mainly, pressure data collection equipment and methods used in the wind tunnel are comparable to pressure data collection equipment and methods used in the field

    Iron and zinc isotopes reveal redox reactions associated with fluid flow in subduction zones:

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    Thesis advisor: Ethan BaxterThesis advisor: Mark BehnSubduction zones are areas of significant mass transfer between Earth’s crust and mantle. The dehydration of water-rich minerals such as serpentinite and lawsonite introduces water and volatiles into the subduction interface, that then travel to the mantle wedge above. The chemical composition, speciation, and redox effect of these fluids carry important implications for arc volcanism and the mobility of economically significant elements. This study uses Fe and Zn isotopic variation in eclogite-breccias from the Monviso ophiolite, combined with Sm-Nd garnet geochronology, to study the composition and redox effects of fluids that were produced during eclogite and blueschist facies metamorphism, and the timescales over which the brecciation and fluid flux events happened. Fe and Zn isotopic measurements were made on a series of four breccia matrix generations (M1-M4), generated during the progressive brecciation of the original Fe-Ti gabbros and the influx of both internally and externally derived fluids. The ∂56Fe and ∂66Zn data display a bi-modal distribution, with early matrix crystallization (M1-3) imparting progressively lighter ∂66Zn values while the ∂56Fe remains relatively unchanged. The last stage of metasomatic rind formation (M4) is associated with a decrease in both Fe and Zn isotopic values and a particularly significant shift in the Fe isotopes. This distribution suggests that early brecciation (M1-3) resulted from small-scale internal fluid flow that did not have a measurable effect on the isotopic composition and redox state of the system. By contrast, late metasomatic rind formation (M4) was facilitated by the flow of large amounts of external fluids with a strongly negative Fe and Zn isotope signature that affected the redox state of the mafic slab and may be responsible for transferring oxidized material into the mantle wedge. Dating of the M4 matrix generation yielded an age of 41.31± 0.60 Ma. A compilation of age data from Monviso suggests peak metamorphism and initial brecciation (M1 formation) likely occurred at ~45 Ma, the formation of the M4 matrix representing the end of eclogite-facies retrogression and brecciation at ~41 Ma, and final blueschist and greenschist retrogression at ~38-35Ma, yielding timescale of ~4Ma for the entire history of brecciation and fluid flux associated with the Monviso eclogite breccias.Thesis (MS) — Boston College, 2022.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Earth and Environmental Sciences

    TermPicks: a century of Greenland glacier terminus data for use in scientific and machine learning applications

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    Marine-terminating outlet glacier terminus traces, mapped from satellite and aerial imagery, have been used extensively in understanding how outlet glaciers adjust to climate change variability over a range of timescales. Numerous studies have digitized termini manually, but this process is labor intensive, and no consistent approach exists. A lack of coordination leads to duplication of efforts, particularly for Greenland, which is a major scientific research focus. At the same time, machine learning techniques are rapidly making progress in their ability to automate accurate extraction of glacier termini, with promising developments across a number of optical and synthetic aperture radar (SAR) satellite sensors. These techniques rely on high-quality, manually digitized terminus traces to be used as training data for robust automatic traces. Here we present a database of manually digitized terminus traces for machine learning and scientific applications. These data have been collected, cleaned, assigned with appropriate metadata including image scenes, and compiled so they can be easily accessed by scientists. The TermPicks data set includes 39 060 individual terminus traces for 278 glaciers with a mean of 136 ± 190 and median of 93 of traces per glacier. Across all glaciers, 32 567 dates have been digitized, of which 4467 have traces from more than one author, and there is a duplication rate of 17 %. We find a median error of ∼ 100 m among manually traced termini. Most traces are obtained after 1999, when Landsat 7 was launched. We also provide an overview of an updated version of the Google Earth Engine Digitization Tool (GEEDiT), which has been developed specifically for future manual picking of the Greenland Ice Sheet

    Differentials of fertility in North and South Gondar zones, northwest Ethiopia: A comparative cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Ethiopia is one of the most densely populated countries in Africa with an estimated population of 77.1 million in mid-2007. Uncontrolled fertility has adversely influenced the socio-economic, demographic and environmental situations of the country. It is one of the largest and poorest countries that, even in the midst of crisis, has maintained high levels of fertility. This study was aimed at investigating the most important factors influencing fertility behavior in Northwest Ethiopia.</p> <p>Methods</p> <p>A comparative cross-sectional study which included 2424 women aged 25 years and above was undertaken in the Amhara region of Northwest Ethiopia. The study subjects were grouped into high fertile and low fertile categories. There were 1011 and 1413 women in the high and low fertile groups, respectively. A multi-stage cluster sampling stratified by place of residence was employed to select the required study subjects. Both bivariate and multivariate logistic regression techniques were used to analyze the data.</p> <p>Results</p> <p>Among the 25 variables considered in this study, only 9 of them were found significantly and independently associated with the level of fertility. Women with at least secondary education were at a lower risk of high fertility with OR = 0.37 (95% CI: 0.21 to 0.64) compared to those with no formal education. However, women with primary education did not show any significant difference when compared with the same baseline group. Age at first marriage was inversely associated with the number of children ever born alive. Place of residence, household expenditure, number of children who have died, attitude towards using contraceptives, women's knowledge on the safe period, and current marital status were the other variables that showed significant associations with the level of fertility.</p> <p>Conclusion</p> <p>Female education beyond the primary level, reduced infant and child mortality, delayed marriage and correct knowledge on the safe period during the menstrual cycle were amongst the main factors that had a bearing on high fertility.</p
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