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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
311

Dynamic Model Pooling Methodology for Improving Aberration Detection Algorithms

Sellati, Brenton J 01 January 2010 (has links) (PDF)
Syndromic surveillance is defined generally as the collection and statistical analysis of data which are believed to be leading indicators for the presence of deleterious activities developing within a system. Conceptually, syndromic surveillance can be applied to any discipline in which it is important to know when external influences manifest themselves in a system by forcing it to depart from its baseline. Comparing syndromic surveillance systems have led to mixed results, where models that dominate in one performance metric are often sorely deficient in another. This results in a zero-sum trade off where one performance metric must be afforded greater importance for a decision to be made. This thesis presents a dynamic pooling technique which allows for the combination of competing syndromic surveillance models in such a way that the resulting detection algorithm offers a superior combination of sensitivity and specificity, two of the key model metrics, than any of the models individually. We then apply this methodology to a simulated data set in the context of detecting outbreaks of disease in an animal population. We find that this dynamic pooling methodology is robust in the sense that it is capable of superior overall performance with respect to sensitivity, specificity, and mean time to detection under varying conditions of baseline data behavior, e.g. controlling for the presence or absence of various levels of trend and seasonality, as well as in simulated out-of-sample performance tests.
312

Creation of three nutritional mixes based on amaranth (Amaranthus caudatus) and other Andean crops for school-aged children (Cochabamba-Bolivia)

Delgadillo Barriga, Sandra Carola 01 January 2002 (has links) (PDF)
In Bolivia we have three very valuable Andean grains: amaranth (Amaranthus caudatus), quinoa (Chenopodium quinua), and canihua (Chenopodium pallidicaule), which combined with cereals and legumes can become a complete and balanced food in order to combat the malnutrition that is so widespread in our region. In this study, various nutritional mixes were formulated, based on amaranth and other Andean crops, and the three best were chosen according to nutrition, palatability, and cost. They were: Andean Baby Food, Mixicereal, and Amaranth Cookie, which have an amino acid complement between 79% and 100% and give satisfactory amounts of protein, energy, and minerals for school-aged children. Afterward, the biological quality of the three foods was determined through biological evaluation studies, determining weight gain to be between 64.26 and 87.28, digestibility between 60% and 78%, and PER between 1.75 and 2.36. The cost of the three final products was less than 0.08 cents of an American dollar for every 100 grams of mix. Finally, sensory analyses were performed on the three products with 90 children, from 5 to 9 years old, from two rural schools in Quillacollo province, Cochabamba, and a preference for Mixicereal was observed. Based on these results, we conclude that the three mixes studied are excellent nutritional complements, with high biological value, sensory acceptability, and within the means of a population with scarce economic resources.
313

Growing Conflict: Agriculture, Innovation, and Immigration in San Luis Obispo County, 1837–1937

Jenzen, Douglas P 01 March 2011 (has links) (PDF)
The history of San Luis Obispo and its surrounding areas is complex. Agriculture, innovation, and immigration have all contributed to the formation of the region. The Spanish, Mexican, and early American periods established the framework successive waves of immigrants had to live within. Native Americans and immigrants from China, Portugal, Switzerland, Japan, the Philippines, and other regions of the United States have all toiled in the fields and contributed to America’s tables at various points throughout county history. Many contingencies determined the treatment of successive waves of immigrants. Growth and development are taking place at exponential rates on the very land that witnessed the first local agriculture and the conflicts surrounding the burgeoning industry.
314

The history of the American fruit industry in the Caribbean

Irons, Oliver Eller 01 January 1929 (has links) (PDF)
The Caribbean countries have attracted increasing interest from students of American political history and the more their history is investigated, the more do we realize the growing significance of the role played by American capital in the development of their industries. The literature of tropical agriculture is coming to be more extensively available but until only recently has this subject received slight attention from our writers. The concentration of any attention on the fruit phase of tropical agriculture by American students of history and economics has been nearly wholly lacking, as well as receiving only scant attention from writers not connected with interests having financial investments in the Caribbean. The American people have every reason to be more actively interested in tropical agriculture, and the general public should familiarize itself more intimately with the tropical fruits that are now fast becoming a staple food for every American household.
315

Developing a precision agriculture framework to assess financial viability of decisions in farming and conservation

Sublett, Jennifer 08 December 2023 (has links) (PDF)
Agricultural producers are invested in managing the impacts of crop damage on their yields and profit. When damage occurs early enough in an agricultural growing season, farmers have the option to replant their corn stand in an effort to recoup some of the lost profits. In this thesis two different types of naturally occurring damage, wildlife depredation and persistent weed or insect patches, were simulated on two representative regions of Mississippi. These data were then used to assess the financial viability of a range of damage mitigation methods, including partial replanting, enrollment into a government conservation buffer, and no action. Replanting was demonstrated to be generally the most economically viable method of management across all simulation scenarios. This analysis showed a lower return on conservation enrollment than expected, indicating that an increase in financial benefits for some conservation programs may be warranted.
316

Impacts of Pollution Control, Ecosystem Conservation, and Infrastructure on the Agriculture-Land-Environment Nexus

Zhan Wang (16627161) 21 July 2023 (has links)
<p>A major challenge of achieving sustainable development is to balance two critical targets with finite resources: to secure food security for a growing population with rising consumption demands, and to prevent further pollution into the environment and losses in ecosystem services. More importantly, the targets of food production and environment protection are not only related to socio-economic and technological development, but also tangled together both ecologically and economically, in particular regarding competition for land – the necessary natural resource for achieving both targets. In view of this, a comprehensive understanding about how to achieve sustainable development requires integrated analyses of the nexus of agricultural production, land use and environmental protection (the “agriculture-land-environment nexus”), interactions between these components,  and their responses to socio-economic development and policies. </p> <p><br></p> <p>This dissertation consists of three essays focusing on the impacts of environmental protection polices and infrastructure on the agriculture-land-environment nexus. The first essay analyzes how pollution reduction influences ecosystem services, with both a theoretical model and also empirical analysis with city-level data from China. Existing literature from the environmental and ecological fields reports that pollution reduction contributes to ecosystem services, but the ecosystem effects via economic channels remain under-addressed. We find when integrated together with an economic system, the reduction of pollution causes losses in the area of natural land that supports ecosystem services, which is further supported by empirical evidence. This finding emphasizes the importance of taking ecosystem effects into account on the design, implementation and evaluation of pollution control policies.</p> <p><br></p> <p>The second essay researches the impact of a large-scale forestry and grassland conservation policy in China, the grain-to-green project (GTGP), on cropland supply and crop production. In this essay, we first develop a theoretical model of the relationships between cropland supply, land value (with market access as proxy) and GTGP, and then empirically test these relationships using gridded data from China. We find GTGP not only directly reduces cropland area, but also restricts the elasticity of cropland supply in response to market access. Furthermore, we apply the GTGP’s impacts on cropland supply elasticity on a grid-solving computable model, in order to both validate the model and elasticity estimates via hindcasting and evaluate the GTGP’s impact on agricultural production via simulation. In the computable model where all grids are connected with crop markets, we find two effects of GTGP on agriculture: the direct effect that restricts cropland use and crop production in regions where it is implemented, and the indirect effect that increases crop production on regions not restricted or less restricted by GTGP. Essay 2 contributes to the literature by not only estimating the pattern of gridded cropland supply in China, but also reveals the indirect effect of GTGP on agriculture, which has seldom been researched. </p> <p><br></p> <p>The third essay researches the impact of transportation infrastructure on Brazilian agriculture, land use, and greenhouse gas (GHG) emissions. Combining a geographic information system (GIS) based analysis and computable model simulation, we find the expansion of infrastructure mainly contributes to the transportation cost reduction in inland Brazil and causes local cropland expansion and increased GHG emissions from land conversion. However, the shifting of crop production towards inland Brazil reduces the demand for cropland in southeastern and southern Brazil, which offsets the impact on cropland expansion and GHG emissions at the national level. Findings in Essay 3 indicate the importance of capturing both spatial heterogeneity and spatial spillover effects of infrastructure expansion when evaluating agricultural and environmental impacts. </p>
317

Assessment of the Economic and Ecosystem Service Contributions of USDA Forest Service Landowner Assistance Programs in the Conterminous United States

Dias, Jacqueline S 18 March 2022 (has links)
Forests provide immense goods and services to both local and regional communities. The USDA Forest Service’s, State and Private Forestry program administer multiple landowner assistance programs aimed at helping private forest owners while supporting the continued supply of ecosystem services (e.g., timber harvesting, recreation, carbon sequestration and storage). The two landowner assistance programs assessed in this study are the Forest Legacy Program (FLP) and the Forest Stewardship Program (FSP). A majority of the nation’s forests are privately owned, many of which are facing deleterious impacts like wildfires, invasive species, development pressures, and other adverse effects from climate change. The goal of this project is to (1) quantify the economic contributions emanating from lands participating in FLP and FSP in the conterminous US and (2) quantify and value the carbon sequestration on lands participating in FLP and FSP in New England. IMPLAN is an input-output modeling system, used in Chapter 1, that estimates how money flows through a regional economy. The results from the IMPLAN analysis suggest that FLP lands in the conterminous US contribute an estimated 4,560 jobs and $306.8 million in value-added from timber harvesting and recreation. Further, FSP lands contribute an estimated 27,700 jobs and $1.8 billion in value added from timber harvesting and recreation. Using Forest Inventory and Analysis carbon sequestration data and the social cost of carbon, the results of chapter 2 suggest that, in New England, FLP lands sequester 147,000 metric tons of CO2, or $7.5 million in aboveground CO2, per year. FSP lands in New England are estimated to sequester 82,000 metric tons of CO2, or $4.1 million in CO2, per year. Quantifying and estimating the economic and ecosystem service contributions emanating from lands participating in FLP and FSP provide a framework for understanding the total benefits associated with these programs (e.g., supporting rural economies, impacting climate change and the global carbon network, etc.).
318

A Prototype Decision Support System for the Productive Reuse of Vacant and Underutilized Urban Land

Kirnbauer, Margaret C. 10 1900 (has links)
<p>Many cities around the world struggle with the presence of vacant and underutilized land in the urban environment. There is growing momentum across many municipal jurisdictions in North America to reuse public and privately held vacant and underutilized urban land on a temporary to potentially permanent basis for community-based projects; however, there are limited community-based tools available to assess the suitability of vacant land for potential reuse.</p> <p>This thesis presents three papers (Chapters 2-4) that describe the development and application of a prototype community-based decision support tool (PDSS), developed in Microsoft ExcelÒ. The PDSS provides a methodology for evaluating up to fifteen community-based reuse strategies across three green infrastructure categories: parks, urban food production, and stormwater/ecosystems management. The PDSS aids in deriving community-focused goals, objectives and solutions for the efficient reuse of vacant and underutilized land.</p> <p>The PDSS includes a vacant and underutilized land inventory for identifying and inventorying the physical and spatial attributes (i.e. location and condition) of vacant and underutilized land across the urban environment (VULI); a methodology for quantifying the suitability of vacant land for a suite of reuse strategies (SSI); a multi-objective, binary-integer programming formulation for the allocation of reuse strategies across the urban environment (LOCAL), and a tool for municipal green infrastructure investment decision-making (DECO).</p> <p>The information derived from VULI and SSI can be used by community groups to help articulate the inherent potential of these spaces for future reuse. If this methodology was adopted at the municipal level, the prototype tool has the potential to expedite applications to reuse city-owned lands on a temporary basis. LOCAL provides a methodology to facilitate the allocation of multiple reuse strategies to a single parcel, to achieve a mix of green infrastructure uses at each site, and provides users with the ability to readily generate “what-if” scenarios based on user-specified allocation constraints. DECO can be utilized to design and investigate material alternatives, maintenance schedules, and different cost regimes, which can be useful for construction and long-term preventative maintenance decision-making. Finally, the results of a tree growth-stormwater attenuation modeling exercise are presented (Chapter 5). The methodology and results presented aid in articulating the stormwater attenuating benefits of trees that are planted on a temporary basis on vacant land.</p> / Doctor of Philosophy (PhD)
319

Spreading The Char: The Importance of Local Compatibility in the Diffusion of Biochar Systems to the Smallholder Agriculture Community Context

Munoz, Laura C. V. 01 May 2014 (has links)
This thesis enters the context of smallholder agriculture communities in the developing world. It explores the potentials of biochar and what biochar systems could bring to the smallholder communities while simultaneously bringing environmental benefits. It then acknowledges the challenges of diffusion –the spreading of an unfamiliar innovation. It seeks to answer the question of what will make diffusion of biochar systems more successful in the smallholder context, fixating on the characteristic of compatibility as well as the role local community members can play in making a new biochar system more visible to the rest of the communities.
320

Politics below the Surface: A Political Ecology of Mineral Rights and Land Tenure Struggles in Appalachia and the Andes

Shade, Lindsay 01 January 2017 (has links)
This dissertation examines how confusion and lack of access to information about subsurface property rights facilitates the rapid acquisition of mineral rights by mining interests, leaving those who live 'above the surface' to contend with complicated corporate and bureaucratic apparatuses. The research focuses on the first proposed state-run large scale mining project in Ecuador, believed to contain copper ores, and on the natural gas hydrofracking industry in three counties in north central West Virginia. Qualitative and visual methods, including mapping, are employed to determine (i.) how the geography of subsurface ownership patterns is changing, (ii.) links between changes in subsurface ownership and surface ownership, and (iii.) how these changes are facilitated or impeded by institutional and governance practices. Rights and permit acquisitions are facilitated by state institutions, which often have strategic interests in mineral development. Accordingly, this research also considers the role of state strategy with respect to the establishment, bureaucratic management, and enforcement of vertical territory, which reflects the state’s interest in and sovereign claim over subterranean resources to benefit the nation. The research finds that the historical separation of subsurface property rights from the surface is associated with a persistent weakening of surface holder claims to land in favor of mining development, and that this weakening has contributed to the long-term persistence of absentee ownership and control over land in Ecuador and West Virginia. Viewing subsurface land deals from the perspective of those whose lives are disrupted on the surface, I conclude from this work that mundane practices such as deed transfers and local micropolitics about land use are significant factors in the lead up to larger scale violences and silences, such as forced displacement and even political imprisonment of activists opposed to extraction.

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