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Optimizing Peak Gust and Maximum Sustained Wind Speed Estimates from Mid-Latitude Wave CyclonesJoyner, Timothy Andrew 12 April 2013 (has links)
Wind storms cause significant damage and economic loss and are a major recurring threat in many countries. Maximum sustained and peak gust weather station data from multiple historic wind storms occurring over more than three decades across Europe were analyzed to identify storm tracks, intensities, and areas of frequent high wind speeds. Wind surfaces for maximum sustained and peak gust winds were estimated based on an anisotropic (directionally-dependent) kriging interpolation methodology. Overall, wind speed magnitudes and high intensity locations were identified accurately for each storm. Directional trends and wind swaths were also consistently located in appropriate locations based on known storm tracks. Anisotropic kriging proved to be superior to isotropic (non-directional) kriging when modeling continental-scale wind storms because of the identification of strong directional correlations across space. Results suggest that coastal areas and mountainous areas experience the highest wind intensities during wind storms. These same areas also experience high variability over short distances and thus the highest error measurements associated with concurrent interpolated surfaces. For this reason, various covariates were utilized in conjunction with the cokriging interpolation technique and improved the interpolated wind surfaces for five wind storms that impacted both the mountainous and topographically-varied Alps region and the coastal regions of Europe. Land cover alone reduced station-measured standard error most significantly in a majority of the models, while aspect and elevation (singularly and collectively) also reduced station standard error in most models as compared to the original kriging models.
Additional comparisons between different areal scales of kriging/cokriging models revealed that some surface wind variability is muted at the continental scale, but identifiable at the local scale. However, major patterns and trends are more difficult to ascertain for local-scale surfaces when compared to continental-scale surfaces. Large station error can be reduced through local kriging/cokriging, but additional research is needed to merge local-scale semivariograms with continental-scale models. Results showed substantial improvements in wind speed surface estimates over previous estimates and have major implications for catastrophe modeling companies, insurance needs, and construction standards. Implications of this research may be transferrable to other geographies and create an impetus for database and covariate improvement.
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Palate Shape and Depth: A Shape Matching and Machine Learning Method for Assessment of Ancestry from Skeletal RemainsMaier, Christopher Allan 15 April 2013 (has links)
The assessment of ancestry from skeletal remains is a vital aspect of forensic anthropology. As such, a myriad of techniques exists for estimating this particular component of the biological profile. The most traditional of these methods utilizes the naked eye and the observers experience. As replicability has become more important, objective, metric techniques have been developed. This study attempts to merge these two subfields: by taking a traditionally non-metric feature, palate shape, and using a computer, evaluating it quantitatively. Using 3D digitizer technology in conjunction with shape matching and machine learning methods common in computer science, palate shape curves were collected from 376 individuals of varying backgrounds from mixed historic and modern contexts. Additionally, measurements were taken to capture palate depth, which is a novel measurement in this study. Results of the computer analysis indicated palate shape was an accurate indicator of ancestry 58% of the time. This number improved slightly when the historic sample was examined on its own (61%), but not to such a degree as to indicate a significant difference. This result may indicate that secular change in the human skeleton is not affecting this region, or at least that secular change does not affect the shape of the palate as it relates to ancestry. Cluster analysis of the curves revealed that the parabolic, hyperbolic, and elliptical shapes are relatively discrete from one another, with the only major overlap in shape being between white and Hispanic individuals. The results regarding depth are rudimentary at this stage; however, results indicate that the depth of the palate in Hispanic individuals is significantly deeper than in other ancestry groups.
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Secular Change in the Rate of Dental ImpactionHeim, Kelly 19 April 2013 (has links)
Current literature on the prevalence of impaction has not addressed the change over time (secular change) as it relates to the dimensions of the dental arcade. It has been suggested both that the prevalence of impaction is increasing and that the dimensions of the dental arcade may be decreasing, but no studies have investigated these two variables in conjunction with one another. This study aims to record secular change in the prevalence of impaction by utilizing two sets of data: individuals from the Terry collection represent a historic population from the late 19th and early 20th centuries, and individuals from the donated skeletal collections housed at the W. M. Bass Forensic Anthropology Center and the Forensic Anthropology and Computer Enhancement Services (FACES) Laboratory represent a contemporary modern population. In addition to recording dental impactions by visual inspection, dental arcade widths and depths were taken in both the maxillae and mandible; these measurements formed a trapezoid with which the relative dental arcade area could be calculated. This study found that the overall prevalence of impaction has increased significantly between the historic and modern samples. The maxillary dental arcade is significantly larger in the modern sample than in the historic; the mandibular dental arcade shows no significant difference. However, scatterplots and linear regression equations show a decrease in the size of the dental arcade area for both the maxillae and the mandible. These results show that secular change in occurring. The proposed negative correlation between the prevalence of dental impaction and the relative size of the dental arcade does appear to exist, although this cannot be statistically demonstrated in this study.
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A City and Its River: An Urban Political Ecology of The Loop and Bridgeport in ChicagoWolf, Garrett Charles 08 May 2012 (has links)
Todays urban environment is produced, both physically and perceptually, by a myriad of factors. Through a comparative study of two Chicago neighborhoods along the Chicago River, the Loop and Bridgeport, I construct the network of political, social, and economic factors that create the urban environment of the Chicago River in and along these places. I explore residents perception of who controls the production of the urban environment as it relates to the Chicago River, and how the socio-environment is created. In this study, I utilize an urban political ecology approach that recognizes that environments produced simultaneously by social and physical processes are historically situated and that there is nothing inherently unnatural about urban, produced environments, but that these environments are a result of historically and spatially contextualized socio-environmental processes. Using this approach in conjunction with interviews, surveys, and participant observation, I analyze these factors to determine who the residents of these neighborhoods perceive as exerting control over the production of the environment of the Chicago River and how these various entities, along with the numerous processes that influence the environment of the river, are mobilized to serve particular purposes. This research allows me to view the interrelated entities that contribute to the production of the environment of the Chicago River as well as to understand that social factors and pressures that have both historically and recently played a larger role in this production than are often ascribed to them by residents.
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Drought in Georgia: Water Scarcity Issues and ImplicationsChaisson, Samantha Kay 05 June 2012 (has links)
Population growth and hydrological drought threaten the water supply of Atlanta,
Georgia. In Georgia, water policy changed rapidly due to stress on the resource, regulation
increased, and the state promoted a culture of conservation to combat water scarcity. This
study examines how regulatory measures, including legislative acts and Governors executive
orders, have impacted the populations attitudes and behaviors towards water consumption.
Furthermore, public spaces are used to measure public perception of water policy, and serve as a
physical representation of the culture shift.
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Understanding Public Perceptions of Global WarmingShao, Wanyun 06 June 2012 (has links)
In this dissertation, I investigate the determinants on Americans perceptions of global warming and individuals environmentally significant behaviors to reduce global warming. Specially, I examine how contextual variables, primarily represented by local weather and climate, attitudinal variables, and socio-demographic characteristics affect public opinion towards global warming, personal voluntary actions and willingness to address global warming.
The research of this dissertation reveals some important findings. First, local weather and climaterepresented by long-term temperature trendsis found to have significant effects on public perceptions of global warming and private-sector environmentally significant behaviors. In particular, the summer temperature trend over the past 10 years has consistently shown to have positive effects on public acceptance of anthropogenic global warming and concern for global warming. In other words, individuals are most sensitive to summer temperature and more likely to translate increasingly hot summers into perceptions of anthropogenic global warming and their concern for this issue. Second, consistent with the results of previous studies, global warming has become a politically polarized issue. Specifically, Democrats and political liberals are more likely than Republicans and political conservatives to accept the notion of anthropogenic global warming, show higher level of concern for global warming, and participate in private-sector environmentally significant behaviors to reduce global warming. Third, attitudinal variables play an important role in affecting public perceptions of global warming and individuals environmentally significant behaviors. For instance, personal attitudes toward scientists are found to be a strong group of predictors on public opinion toward global warming. In addition, attitudinal variablesincluding individuals environmental views and perceptions of global warmingoutperform socio-demographic characteristics and contextual forces in explaining the variance of personal actions and public willingness to pay more to reduce global warming. Finally, objective macro-economic conditions, represented by county-level unemployment rate in this dissertation are not found to have any consistently significant effect on either public perceptions of global warming or individuals environmentally significant behaviors.
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Urban Population Density and Environmental Quality in Port-au-Prince, Haiti: A Geo-Statistical AnalysisJoseph, Myrtho 14 June 2012 (has links)
This dissertation revolves around three issues on the urban area of Port-au-Prince, Haiti: the population distribution pattern, its estimation from remote sensing images, and its relationship with environmental quality. It follows a three-paper format. Paper 1 examines the population density pattern by the monocentric and polycentric models, based on the 2003 census data. The regression results show a poor fitting power of monocentric functions, and improved but less than satisfactory R2 by polycentric functions. A five-sector conceptual model is proposed to capture the urban structure shaped by the absence or lack of institutional enforcement of land use regulations and urban planning. Paper 2 proposes a population estimation model based on Landsat ETM+ images that are widely available. The subpixel vegetation-impervious surface-soil (VIS) fractions derived from the Landsat multispectral bands (the mean value of houses fraction image, the mean value of vegetation and the standard deviation of vegetation fraction image) are used as predictors for urban population density. The research indicates that the geographically weighted regression (GWR) model, which accounts for spatial non-stationarity, performs much better than its Ordinary Least Square counterpart. Paper 3 uses multiple factors to assess and map the urban environmental quality (UEQ). In addition to parameters typically considered in previous studies, this study includes natural hazards and other parameters unique to Port-au-Prince. Crowdedness, waste, lack of vegetation, presence of slums and water body pollutions are considered as the most critical factors (negatively) affecting the quality of the environment in Port-au-Prince. All are exacerbated by population pressure on the resources, i.e., population density. The scores for corresponding factors are integrated together by weights extracted from a panel of local experts. The overall UEQ results are validated by field surveys. Each paper discusses important implications of major findings for public policy and planning
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An Analysis of Tropical Storm Surge Trends for the Atlantic Coast of the United StatesBeckage, Stephen 19 June 2012 (has links)
Tropical cyclone generate storm surge is responsible for damage to lives and livelihoods on a global scale. In spite of this inherent danger, the scientific community currently lacks a global database of peak storm surge events. Thus, SURGEDAT was created to fill this void. Research began on the Gulf of Mexico, and the research presented here creates a database of peak surges for the Atlantic Coast of the United States (ACUS) between the years of 1898-2011. A total of 25 sources were utilized for creation of this database, with many more being consulted but not included in the final product. A database of 72 surge events ≥ 1.22 m was created, with the largest event being a 6.49 m surge in Fairhaven, MA in 1938. Spatial analysis reveals high levels of surge activity in south Florida and North Carolina, with diminished activity from Virginia to Maine. Statistical analysis tested surge frequency and magnitude versus two teleconnections: the Atlantic Multidecadal Oscillation (AMO), and the Southern Oscillation Index (SOI). Statistically significant links were found between AMO phase and surge frequencies; however, no links were found between AMO phase and surge height. No statistically significant links between SOI and magnitude or frequency were detected. Return periods associated with surge events were calculated through three quantile estimation methods the Pareto distribution and the Huff-Angel and Southern Regional Climate Center (SRCC) linear regression methods. The SRCC method produced the best quantile estimates of surge heights along the ACUS, with a 100-yr event of 6.49 m and a 2-yr event of 1.55 m. A K-means cluster analysis was performed to split the ACUS region into 10 zones, and the SRCC method was employed to produce quantile estimates on a regional level. Zone 7, centered on Charleston, SC, produced the highest 100-yr return period (5.64 m), followed by Zone 1, centered on New Bedford, MA (5.61 m).
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GIS-Based Urban Land Use Characterization and Population Modeling with Subpixel Information Measured from Remote Sensing DataTang, Quan 21 June 2012 (has links)
This dissertation provides deeper understanding on the application of Vegetation-Impervious Surface-Soil (V-I-S) model in the urban land use characterization and population modeling, focusing on New Orleans area.
Previous research on the V-I-S model used in urban land use classification emphasized on the accuracy improvement while ignoring the discussion of the stability of classifiers. I developed an evaluation framework by using randomization techniques and decision tree method to assess and compare the performance of classifiers and input features. The proposed evaluation framework is applied to demonstrate the superiority of V-I-S fractions and LST for urban land use classification. It could also be applied to the assessment of input features and classifiers for other remote sensing image classification context.
An innovative urban land use classification based on the V-I-S model is implemented and tested in this dissertation. Due to the shape of the V-I-S bivariate histogram that resembles topological surfaces, a pattern that honors the Lu-Wengs urban model, the V-I-S feature space is rasterized into grey-scale image and subsequently partitioned by marker-controlled watershed segmentation, leading to an urban land use classification. This new approach is proven to be insensitive to the selection of initial markers as long as they are positioned around the underlying watershed centers.
This dissertation links the population distribution of New Orleans with its physiogeographic conditions indicated by the V-I-S sub-pixel composition and the land use information. It shows that the V-I-S fractions cannot be directly used to model the population distribution. Both the OLS and GWR models produced poor model fit. In contrast, the land use information extracted from the V-I-S information and LST significantly improved regression models. A three-class land use model is fitted adequately. The GWR model reveals the spatial nonstationarity as the relationship between the population distribution and the land use is relatively poor in the city center and becomes stronger towards the city fringe, depicting a classic urban concentric pattern. It highlighted that New Orleans is a complex metropolitan area, and its population distribution cannot be fully modeled with the physiogeographic measurements.
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GIS-Based Spatial Analysis of Place Names in Yunnan, ChinaZhang, Ling 05 September 2012 (has links)
Yunnan, with the largest number of minority languages in China, is labeled as The Museum of Dialects. The rich diversity of ethnic groups is reflected in its toponyms (place names). The objectives of this study are to (1) construct a GIS database of toponyms in Yunnan at the prefecture, county and township levels from a comprehensive toponymical dictionary series of China; (2) analyze the spatial distribution of Han, Tibeto-Burman (Zang-Mian) and Kam-Tai (Zhuang-Dong) toponyms and its association with environmental factors; and (3) examine the historical evolution of toponyms. Results show that the study shows that the highest concentrations of Zang-Mian toponyms are in north and the eastern mountainous areas, and Zhuang-Dong concentrate in the southwest and southeast areas with lower elevations. Statistical analysis reveals that Zhuang-Dong toponyms tend to have lower elevations than Han toponyms, and Zang-Mian toponyms tend to in places higher than Han toponyms. Both minority groups of toponyms are slightly farther from rivers but closer to railways or the major cities than Han toponyms. The standard distance and standard deviation methods help reveal the historical trend of gradual expansion of Han settlement in Yunnan as recorded in the time stamps of toponyms. In Ming Dynasty,Han people spreaded out into south and north, especially the north area. In the Qing Dynasty, Han people expanded to the frontier areas. This suggests that the most significant spread of Han settlement in Yunnan happened in the Qing dynasty.
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