subject:(Spatial Heterogeneity)

Penn State University

1. Chao, Tse-hua. Mineral Spatial Distribution and Flow Velocity in Determining Calcite Dissolution Rates in Porous Media.

Degree: 2014, Penn State University

URL: https://submit-etda.libraries.psu.edu/catalog/21207

► This work investigates the effects of mineral spatial distribution in porous media on dissolution rates. We measured the calcite dissolution rates by using column experiments,… (more)

▼ This work investigates the effects of mineral spatial distribution in porous media on dissolution rates. We measured the calcite dissolution rates by using column experiments, which are packed with the same amount of calcite mass but different mineral distributed patterns in quartz-sand column (the mixed, 2-cylinder, 1-cylinmder column). The scale of each column is 2.65 cm in diameter and 10 cm in length. The mixed column has a homogeneously distributed calcite in the quartz column , and the 1-cylinder/2-cylinder column confines all the calcite particles within the middle cylindrical zone(s) that is parallel to the flow injection. We flushed the columns with acidic water at various flow velocities. Experimental data show the dissolution rate of calcite is approximately 1.6 to 2 times slower in the 1-cylinder column than in the mixed column, and the rates are about 1.6-2 orders of magnitude lower under the slowest flow velocity (0.31 m/day) compared to the fast flow velocity (m/day). Ratio (α) demonstrates the mineral spatial distributed effect playing an important role in column-scale rates. This is, the mineral spatial distributed effect is more significant under the conditions with fastest flow velocity and less homogeneously distributed reactive minerals (1-cylinder column). In the 1-cylinder column, the 2-D spatial profile modeling shows that the dissolution rates are larger by orders of magnitude at the calcite-quartz interface than the central region within the middle calcite-packed zone. Also, the range of dissolving calcite area at the calcite-quartz interface becomes wider with the increasing transverse dispersivity and under fast flow velocities. In contrast, transverse dispersivity does not affect local dissolution rates in the mixed column and all the calcite are dissolving. From those observations, we infer that transverse dispersivity caused by different mineral spatial distribution controls the mass transport in transverse direction. Two calculations in effective surface area are introduced to understand the above observations:(1) total surface area (AT), representing the total calcite surface area by assuming that all the calcite particles are dissolving; (2) effective surface area (Ae), which is the surface area of effectively dissolving calcite at the calcite-quartz interface and inlet. Column-scale bulk rates (mol/s) increase with the increasing Ae values while remain irrelevant to AT values. Also, the Ae values increases with the increasing flow velocities. This suggests that the different measures in the surface area and flow velocities can be the possibilities causing the discrepancies between field and laboratorial measure rates. This work provides the way to minimize the discrepancies in order to approach the calcite dissolution rate under natural subsurface conditions. The surface area of dissolving calcite at the interface of calcite and other non-reactive minerals needs be measured first, and then the rate constant (mol/m2/s) obtained in laboratory work can be used to infer the real rates.… Advisors/Committee Members: Li Li, Thesis Advisor/Co-Advisor.

Subjects/Keywords: calcite dissolution rate; spatial heterogeneity; mineral spatial distribution

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chao, T. (2014). Mineral Spatial Distribution and Flow Velocity in Determining Calcite Dissolution Rates in Porous Media. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/21207

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chao, Tse-hua. “Mineral Spatial Distribution and Flow Velocity in Determining Calcite Dissolution Rates in Porous Media.” 2014. Thesis, Penn State University. Accessed March 08, 2021. https://submit-etda.libraries.psu.edu/catalog/21207.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chao, Tse-hua. “Mineral Spatial Distribution and Flow Velocity in Determining Calcite Dissolution Rates in Porous Media.” 2014. Web. 08 Mar 2021.

Vancouver:

Chao T. Mineral Spatial Distribution and Flow Velocity in Determining Calcite Dissolution Rates in Porous Media. [Internet] [Thesis]. Penn State University; 2014. [cited 2021 Mar 08]. Available from: https://submit-etda.libraries.psu.edu/catalog/21207.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chao T. Mineral Spatial Distribution and Flow Velocity in Determining Calcite Dissolution Rates in Porous Media. [Thesis]. Penn State University; 2014. Available from: https://submit-etda.libraries.psu.edu/catalog/21207

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Cincinnati

2. Cornwall, Gary J. Three Essays on Bayesian Econometric Methods.

Degree: PhD, Business: Business Administration, 2017, University of Cincinnati

URL: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504801632767553

► This dissertation contains three essays examining new Bayesian econometric methodologies. The first develops a heterogeneous Spatial Autoregressive Model by integrating a finite mixture model structure… (more)

▼ This dissertation contains three essays examining new Bayesian econometric methodologies. The first develops a heterogeneous Spatial Autoregressive Model by integrating a finite mixture model structure into the traditional homogeneous specification. The second essay builds upon the first by extending this Spatial Mixture Model structure to the more general Spatial Durbin and Spatial Durbin Error specifications. Additionally, this essay covers the interpretation of these new model specifications. Finally, the third essay develops a predictive based model selection process by integrating cross-validation algorithms into standard Bayesian sampling methods with a focus on explicit out-of-sample prediction. 1.0.1 Embracing Heterogeneity: The Spatial Autoregressive Mixture ModelIn this essay, a mixture distribution model is extended to include spatial dependence of the autoregressive type. The resulting model nests both spatial heterogeneity and spatial dependence as special cases. A data generation process is outlined that incorporates both a finite mixture of normal distributions and spatial dependence. Whether group assignment is completely random by nature or displays some locational "pattern", the proposed spatial-mix estimation procedure is always able to recover the true parameters. As an illustration, a basic hedonic price model is investigated that includes sub-groups of data with heterogeneous coefficients in addition to spatially clustered elements. 1.0.2 Spatial Durbin Mixture ModelsThis essay extends the finite mixture model structure to include Spatial Durbin and Spatial Durbin Error model specifications. The partial derivatives of this heterogeneous spatial model structure are shown to differ between border and interior agents; the designation of which is based on group assignment and first order neighbor designation. As an illustration, individual income based on data from the Panel Study of Income Dynamics (PSID) is examined using the Spatial Durbin Mixture Model specification.Results from the model indicate that returns to income from education are heterogeneous with some agents receiving negative returns on each additional year of human capital development. 1.0.3 Bayesian Predictive Model Selection using Cross-ValidationIn this essay, leave-one-out cross-validation is combined with Bayesian sampling and inference to develop a new model selection process. This process relies both upon standard hypothesis testing, and, in the absence of sufficient evidence, Ockham's Razor to selection a model from a competing set. It is shown that this process outperforms many of the criteria used in empirical work both by selected the true process more often, and selecting a smaller set of models overall. Advisors/Committee Members: Parent, Olivier (Committee Chair).

Subjects/Keywords: Economics; Spatial Econometrics; Predictive Model Selection; Bayesian Econometrics; Spatial Dependence; Spatial Heterogeneity

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Cornwall, G. J. (2017). Three Essays on Bayesian Econometric Methods. (Doctoral Dissertation). University of Cincinnati. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504801632767553

Chicago Manual of Style (16^th Edition):

Cornwall, Gary J. “Three Essays on Bayesian Econometric Methods.” 2017. Doctoral Dissertation, University of Cincinnati. Accessed March 08, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504801632767553.

MLA Handbook (7^th Edition):

Cornwall, Gary J. “Three Essays on Bayesian Econometric Methods.” 2017. Web. 08 Mar 2021.

Vancouver:

Cornwall GJ. Three Essays on Bayesian Econometric Methods. [Internet] [Doctoral dissertation]. University of Cincinnati; 2017. [cited 2021 Mar 08]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504801632767553.

Council of Science Editors:

Cornwall GJ. Three Essays on Bayesian Econometric Methods. [Doctoral Dissertation]. University of Cincinnati; 2017. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504801632767553

University of California – Berkeley

3. Uno, Hiromi. Spatial and temporal linkage of stream-riparian food webs by seasonal migration of mayfly Ephemerella maculata.

Degree: Integrative Biology, 2016, University of California – Berkeley

URL: http://www.escholarship.org/uc/item/9645x8q3

► Stream environments are spatially and temporally heterogeneous. Mainstem rivers are often wide, sunlit, warm and productive, while tributaries are shaded by riparian trees, unproductive, and… (more)

▼ Stream environments are spatially and temporally heterogeneous. Mainstem rivers are often wide, sunlit, warm and productive, while tributaries are shaded by riparian trees, unproductive, and remain cool in summer. Within mainstem rivers themselves there is substantial spatial heterogeneity in habitat structure and physical conditions, such as water temperature. River environments also change dramatically with season. Organisms that live in the riverine environment respond to and take advantage of such heterogeneous environments by moving between microhabitats or shifting their phenology. I studied the life cycle of a riverine mayfly, Ephemerella maculata (Ephemerellidae), in a northern California river system, its responses to spatial and temporal heterogeneity, and how its movements connect stream and riparian food webs in space and time. I discovered that E. maculata migrates between the mainstem and tributaries of rivers during its life cycle, thereby linking food webs in these two habitats, and enhancing predator growth in unproductive tributaries. The resource subsidy from productive but warm rivers to cool, unproductive tributaries associated with the mayfly migration increase the growth of stenothermic predators like juvenile salmonids in otherwise food-limited, cool thermal refuges, and increase their resilience to future warming. Furthermore, I examined the resilience of E. maculata to changes in water temperature using field surveys and lab rearing experiments. I discovered that different life stages of E. maculata have different thermal responses, and they shift their phenology depending on the water temperature, allowing each life stage to occur in the most desirable thermal condition. Therefore, as long as the natural seasonal pattern of the water temperature is sustained, E. maculata can resist temperature changes by shifting their phenology. Finally, I have shown that thermal spatial heterogeneity of rivers desynchronizes mayfly emergence timing, prolonging the subsidy period to riparian predators, and changing the predators’ responses to this subsidy.

Subjects/Keywords: Ecology; Aquatic sciences; aquatic insect; aquatic-terrestrial linkage; food web; spatial heterogeneity; subsidy; temporal heterogeneity

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Uno, H. (2016). Spatial and temporal linkage of stream-riparian food webs by seasonal migration of mayfly Ephemerella maculata. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/9645x8q3

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Uno, Hiromi. “Spatial and temporal linkage of stream-riparian food webs by seasonal migration of mayfly Ephemerella maculata.” 2016. Thesis, University of California – Berkeley. Accessed March 08, 2021. http://www.escholarship.org/uc/item/9645x8q3.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Uno, Hiromi. “Spatial and temporal linkage of stream-riparian food webs by seasonal migration of mayfly Ephemerella maculata.” 2016. Web. 08 Mar 2021.

Vancouver:

Uno H. Spatial and temporal linkage of stream-riparian food webs by seasonal migration of mayfly Ephemerella maculata. [Internet] [Thesis]. University of California – Berkeley; 2016. [cited 2021 Mar 08]. Available from: http://www.escholarship.org/uc/item/9645x8q3.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Uno H. Spatial and temporal linkage of stream-riparian food webs by seasonal migration of mayfly Ephemerella maculata. [Thesis]. University of California – Berkeley; 2016. Available from: http://www.escholarship.org/uc/item/9645x8q3

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Montana

4. Stover, Kyle Crosby. Heterogeneity of Stand Structure, Fuels, and Wildfire Hazard in Dry and Moist Old-Growth Ponderosa Pine Forests: Case Studies from Western Montana.

Degree: MS, 2011, University of Montana

URL: https://scholarworks.umt.edu/etd/514

► Silvicultural restoration treatments are increasingly proposed to restore ecological function and remediate catastrophic wildfire hazards in old-growth ponderosa pine stands throughout the western United States.… (more)

Subjects/Keywords: heterogeneity; old-growth restoration; spatial heterogeneity; wildfire hazards; Old-growth ponderosa pine; western Montana

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APA (6^th Edition):

Stover, K. C. (2011). Heterogeneity of Stand Structure, Fuels, and Wildfire Hazard in Dry and Moist Old-Growth Ponderosa Pine Forests: Case Studies from Western Montana. (Masters Thesis). University of Montana. Retrieved from https://scholarworks.umt.edu/etd/514

Chicago Manual of Style (16^th Edition):

Stover, Kyle Crosby. “Heterogeneity of Stand Structure, Fuels, and Wildfire Hazard in Dry and Moist Old-Growth Ponderosa Pine Forests: Case Studies from Western Montana.” 2011. Masters Thesis, University of Montana. Accessed March 08, 2021. https://scholarworks.umt.edu/etd/514.

MLA Handbook (7^th Edition):

Stover, Kyle Crosby. “Heterogeneity of Stand Structure, Fuels, and Wildfire Hazard in Dry and Moist Old-Growth Ponderosa Pine Forests: Case Studies from Western Montana.” 2011. Web. 08 Mar 2021.

Vancouver:

Stover KC. Heterogeneity of Stand Structure, Fuels, and Wildfire Hazard in Dry and Moist Old-Growth Ponderosa Pine Forests: Case Studies from Western Montana. [Internet] [Masters thesis]. University of Montana; 2011. [cited 2021 Mar 08]. Available from: https://scholarworks.umt.edu/etd/514.

Council of Science Editors:

Stover KC. Heterogeneity of Stand Structure, Fuels, and Wildfire Hazard in Dry and Moist Old-Growth Ponderosa Pine Forests: Case Studies from Western Montana. [Masters Thesis]. University of Montana; 2011. Available from: https://scholarworks.umt.edu/etd/514

University of Arkansas

5. Mancini, Mattia Ciro. Addressing Genetic Pollution from Pollen Drift on a Heterogeneous Landscape.

Degree: MS, 2015, University of Arkansas

URL: https://scholarworks.uark.edu/etd/1028

► Genetically modified (GM) crops are crops in which single or multiple genes have been introduced artificially in order to obtain certain characteristics that are… (more)

▼ Genetically modified (GM) crops are crops in which single or multiple genes have been introduced artificially in order to obtain certain characteristics that are difficult to obtain through conventional breeding. Even though farmers have the right to freely choose what types of crops to grow, pollen mediated gene flow from GM crops to non-GM crops can limit the possibility for crops to coexist on a same landscape, resulting in economic losses that depend on the institutional arrangements and the type of property rights in place. Although it is well known that spatial variability affects the degree of cross-contamination between GM and non-GM crops, no spatial analysis has been carried out to investigate how heterogeneity of landscapes influences the possibility for GM and non-GM crops to coexist. We aim with this research to analyze how spatial variability affects land allocation between GM and non-GM corn crops through a model composed of two parts: the first one simulates spatial units based on landscape criteria through Voronoi diagrams, and the second one reallocates the land between buffers, the GM and the non-GM crop based on cross-contamination and initial assignment of property rights. The model identifies coexistence clusters based on the deviation from an initial land allocation. We show that increasing spatial variability reduces the possibility of acceptable coexistence of crops and increases the economic losses. The economic impact from the assignment of property rights depends on the parameters that drive profitability differences (average market prices, yields and production costs). We show that buffer zones enforced to reduce cross-contamination result in less coexistence in heterogeneous spatial situations. We also elicit the economic value of unobserved factors that create a competitive advantage for certain farmers necessary for alternative crops to coexist on the same landscape. Advisors/Committee Members: Kent Kovacs, Konrad Hagedorn, Eric J. Wailes.

Subjects/Keywords: Social sciences; Coexistence; GMOs; Simulation; Spacial economics; Spatial heterogeneity; Spatial optimization; Agricultural Economics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Mancini, M. C. (2015). Addressing Genetic Pollution from Pollen Drift on a Heterogeneous Landscape. (Masters Thesis). University of Arkansas. Retrieved from https://scholarworks.uark.edu/etd/1028

Chicago Manual of Style (16^th Edition):

Mancini, Mattia Ciro. “Addressing Genetic Pollution from Pollen Drift on a Heterogeneous Landscape.” 2015. Masters Thesis, University of Arkansas. Accessed March 08, 2021. https://scholarworks.uark.edu/etd/1028.

MLA Handbook (7^th Edition):

Mancini, Mattia Ciro. “Addressing Genetic Pollution from Pollen Drift on a Heterogeneous Landscape.” 2015. Web. 08 Mar 2021.

Vancouver:

Mancini MC. Addressing Genetic Pollution from Pollen Drift on a Heterogeneous Landscape. [Internet] [Masters thesis]. University of Arkansas; 2015. [cited 2021 Mar 08]. Available from: https://scholarworks.uark.edu/etd/1028.

Council of Science Editors:

Mancini MC. Addressing Genetic Pollution from Pollen Drift on a Heterogeneous Landscape. [Masters Thesis]. University of Arkansas; 2015. Available from: https://scholarworks.uark.edu/etd/1028

University of Cambridge

6. Watkinson-Powell, Benjamin. Modelling spatial strategies for the durable deployment of crop disease resistance.

Degree: PhD, 2020, University of Cambridge

URL: https://doi.org/10.17863/CAM.55849 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814528

► Maximising the durability of crop disease resistance genes in the face of pathogen evolution is a major challenge in modern agricultural epidemiology. Spatial diversification in… (more)

▼ Maximising the durability of crop disease resistance genes in the face of pathogen evolution is a major challenge in modern agricultural epidemiology. Spatial diversification in the deployment of resistance genes, where susceptible and resistant fields are more closely intermixed, is predicted to drive lower epidemic intensities over evolutionary timescales. This is due to an increase in the strength of dilution effects, caused by pathogen inoculum challenging host tissue to which it is not well-specialised. The factors that interact with and determine the magnitude of this spatial effect are not currently well understood however, leading to uncertainty over the pathosystems where such a strategy is most likely to be cost-effective. We initially use a spatially explicit model, incorporating seasonality and localised reservoirs of inoculum, to explore disease dynamics within landscapes containing a mixture of fields planted with either susceptible or resistant cultivars. When the spatial diversification of these fields is maximised, with lower aggregation of similar fields, the overall intensity of the landscape scale epidemic is reduced. The strength of this spatial effect however depends strongly on the pathogen dispersal characteristics, any fitness cost(s) of the resistance breaking trait, the efficacy of host resistance, and the length of the timeframe of interest. The conclusions drawn from this initial work, about how multi-strain disease dynamics respond to the scale of spatial diversification in a multi-host landscape, allow us to construct a general spatially implicit model that captures these fundamental dynamics. This new model features a novel method for incorporating spatial structure using an intuitive spatial aggregation metric that can be easily estimated from spatially explicit landscape data. The model is simple enough to be amenable to mathematical invasion analysis, while being flexible enough that questions of resistance durability can be thoroughly explored. In particular, results demonstrating interaction between spatial heterogeneity and cultivar cropping ratio are presented, an investigation that was not easily possible in our earlier more complex model. These results indicate that optimal spatial deployment strategies depend on a variety of factors, and may not necessarily be constant over time. Overall, these models allow us to make general predictions of the types of system for which spatial diversification is most likely to be cost-effective, paving the way for potential economic modelling and pathosystem specific evaluation. In addition, this approach for capturing detailed spatial structure and multi-species interactions within simple mathematical models could be applied to a wide variety of ecological and evolutionary systems. This study highlights the importance of studying the effect of genetics on landscape scale spatial dynamics within host-pathogen disease systems, as well as providing new mathematical tools to do so.

Subjects/Keywords: Evolutionary epidemiology; Crop disease; Durable resistance; Mathematical modelling; Optimal deployment; Spatial dynamics; Spatial heterogeneity

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Watkinson-Powell, B. (2020). Modelling spatial strategies for the durable deployment of crop disease resistance. (Doctoral Dissertation). University of Cambridge. Retrieved from https://doi.org/10.17863/CAM.55849 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814528

Chicago Manual of Style (16^th Edition):

Watkinson-Powell, Benjamin. “Modelling spatial strategies for the durable deployment of crop disease resistance.” 2020. Doctoral Dissertation, University of Cambridge. Accessed March 08, 2021. https://doi.org/10.17863/CAM.55849 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814528.

MLA Handbook (7^th Edition):

Watkinson-Powell, Benjamin. “Modelling spatial strategies for the durable deployment of crop disease resistance.” 2020. Web. 08 Mar 2021.

Vancouver:

Watkinson-Powell B. Modelling spatial strategies for the durable deployment of crop disease resistance. [Internet] [Doctoral dissertation]. University of Cambridge; 2020. [cited 2021 Mar 08]. Available from: https://doi.org/10.17863/CAM.55849 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814528.

Council of Science Editors:

Watkinson-Powell B. Modelling spatial strategies for the durable deployment of crop disease resistance. [Doctoral Dissertation]. University of Cambridge; 2020. Available from: https://doi.org/10.17863/CAM.55849 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814528

University of Cambridge

7. Watkinson-Powell, Benjamin. Modelling spatial strategies for the durable deployment of crop disease resistance.

Degree: PhD, 2020, University of Cambridge

URL: https://www.repository.cam.ac.uk/handle/1810/308761

► Maximising the durability of crop disease resistance genes in the face of pathogen evolution is a major challenge in modern agricultural epidemiology. Spatial diversification in… (more)

▼ Maximising the durability of crop disease resistance genes in the face of pathogen evolution is a major challenge in modern agricultural epidemiology. Spatial diversification in the deployment of resistance genes, where susceptible and resistant fields are more closely intermixed, is predicted to drive lower epidemic intensities over evolutionary timescales. This is due to an increase in the strength of dilution effects, caused by pathogen inoculum challenging host tissue to which it is not well-specialised. The factors that interact with and determine the magnitude of this spatial effect are not currently well understood however, leading to uncertainty over the pathosystems where such a strategy is most likely to be cost-effective. We initially use a spatially explicit model, incorporating seasonality and localised reservoirs of inoculum, to explore disease dynamics within landscapes containing a mixture of fields planted with either susceptible or resistant cultivars. When the spatial diversification of these fields is maximised, with lower aggregation of similar fields, the overall intensity of the landscape scale epidemic is reduced. The strength of this spatial effect however depends strongly on the pathogen dispersal characteristics, any fitness cost(s) of the resistance breaking trait, the efficacy of host resistance, and the length of the timeframe of interest. The conclusions drawn from this initial work, about how multi-strain disease dynamics respond to the scale of spatial diversification in a multi-host landscape, allow us to construct a general spatially implicit model that captures these fundamental dynamics. This new model features a novel method for incorporating spatial structure using an intuitive spatial aggregation metric that can be easily estimated from spatially explicit landscape data. The model is simple enough to be amenable to mathematical invasion analysis, while being flexible enough that questions of resistance durability can be thoroughly explored. In particular, results demonstrating interaction between spatial heterogeneity and cultivar cropping ratio are presented, an investigation that was not easily possible in our earlier more complex model. These results indicate that optimal spatial deployment strategies depend on a variety of factors, and may not necessarily be constant over time. Overall, these models allow us to make general predictions of the types of system for which spatial diversification is most likely to be cost-effective, paving the way for potential economic modelling and pathosystem specific evaluation. In addition, this approach for capturing detailed spatial structure and multi-species interactions within simple mathematical models could be applied to a wide variety of ecological and evolutionary systems. This study highlights the importance of studying the effect of genetics on landscape scale spatial dynamics within host-pathogen disease systems, as well as providing new mathematical tools to do so.

Subjects/Keywords: Evolutionary epidemiology; Crop disease; Durable resistance; Mathematical modelling; Optimal deployment; Spatial dynamics; Spatial heterogeneity

Record Details Similar Records Cite « Share

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Watkinson-Powell, B. (2020). Modelling spatial strategies for the durable deployment of crop disease resistance. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/308761

Chicago Manual of Style (16^th Edition):

Watkinson-Powell, Benjamin. “Modelling spatial strategies for the durable deployment of crop disease resistance.” 2020. Doctoral Dissertation, University of Cambridge. Accessed March 08, 2021. https://www.repository.cam.ac.uk/handle/1810/308761.

MLA Handbook (7^th Edition):

Watkinson-Powell, Benjamin. “Modelling spatial strategies for the durable deployment of crop disease resistance.” 2020. Web. 08 Mar 2021.

Vancouver:

Watkinson-Powell B. Modelling spatial strategies for the durable deployment of crop disease resistance. [Internet] [Doctoral dissertation]. University of Cambridge; 2020. [cited 2021 Mar 08]. Available from: https://www.repository.cam.ac.uk/handle/1810/308761.

Council of Science Editors:

Watkinson-Powell B. Modelling spatial strategies for the durable deployment of crop disease resistance. [Doctoral Dissertation]. University of Cambridge; 2020. Available from: https://www.repository.cam.ac.uk/handle/1810/308761

University of California – Berkeley

8. Christianson, Danielle Svehla. Fine-scale Environmental Variation in Mountain Landscapes: Quantitative approaches, influences on tree recruitment, and implications for scientific visualization.

Degree: Energy & Resources, 2016, University of California – Berkeley

URL: http://www.escholarship.org/uc/item/80142362

► Individual organisms respond to environmental conditions that they experience on fine spatial and temporal scales, on the order of meters and hours. For example, a… (more)

▼ Individual organisms respond to environmental conditions that they experience on fine spatial and temporal scales, on the order of meters and hours. For example, a tree seedling lives or dies depending on local conditions, such as freezing temperatures on a spring morning, dry soils and air in the late summer, or a gopher that finds newly grown leaf tissue tasty. The persistence of a species depends on the collective survival of individuals throughout time and at various locations in space. To be of practical use to resource managers and policy makers, tools that inform human action and non-action with regard to other species, and the ecological processes that connect us, must operate at coarse spatial (10-100s km) and temporal (years-decades) scales and be applicable to many species. A core task then is to link ecological phenomena across spatiotemporal scales. An understanding of fine-scale environs and their influence on organisms is necessary to address this challenge, but it is lacking. A primary focus of my research is to characterize (1) the fine-scale environs (1-meter and hourly resolution) over relatively large extents (1 continuous hectare), and (2) their influence on individual organisms. I chose to study mountainous systems because fine-scale environmental descriptions in these highly complex landscapes are few. Additionally, I focused on spatiotemporal characterization of fine-scale heterogeneity as it is increasingly being used, with average conditions, to explain ecological phenomena.In chapter 1, I systematically studied the effects of sampling designs and landscape features on a measure of fine-scale heterogeneity. I found that appropriate sampling designs can reduce error in estimating fine-scale heterogeneity on complex landscapes. In chapter 2, I report that temporal patterns in fine-scale spatial heterogeneity are consistent across four mountainous landscapes and are highly variable both daily and seasonally. For some environmental quantities, aggregated temporal metrics do not adequately represent fine-scale heterogeneity. In chapter 3, I investigated the influences of fine-scale environmental conditions on the occupancy patterns of tree seedlings. Individual tree seedlings are influenced by fine-scale abiotic and biotic environmental conditions. However, the mechanism for some biotic interactions may occur indirectly via fine-scale abiotic influences. I recommend making this distinction to enable advances in coarse-scale modeling tools. In chapter 4, I questioned how new visualizations of the natural world based on fine-scale data shape ecological practice. Such visualizations enable lively novel interactions that may lead to new insight. Ecologists should approach such practice with an understanding of how these new, often highly technical, visualizations shape knowledge generation for themselves individually and the community as a whole.Videos for chapter 4, included as additional files, illustrate experiences in a forested study site and experiences with a digital point cloud visualization…

Subjects/Keywords: Ecology; Multimedia communications; heterogeneity; microclimate; seedling; spatial; visualization

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Christianson, D. S. (2016). Fine-scale Environmental Variation in Mountain Landscapes: Quantitative approaches, influences on tree recruitment, and implications for scientific visualization. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/80142362

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Christianson, Danielle Svehla. “Fine-scale Environmental Variation in Mountain Landscapes: Quantitative approaches, influences on tree recruitment, and implications for scientific visualization.” 2016. Thesis, University of California – Berkeley. Accessed March 08, 2021. http://www.escholarship.org/uc/item/80142362.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Christianson, Danielle Svehla. “Fine-scale Environmental Variation in Mountain Landscapes: Quantitative approaches, influences on tree recruitment, and implications for scientific visualization.” 2016. Web. 08 Mar 2021.

Vancouver:

Christianson DS. Fine-scale Environmental Variation in Mountain Landscapes: Quantitative approaches, influences on tree recruitment, and implications for scientific visualization. [Internet] [Thesis]. University of California – Berkeley; 2016. [cited 2021 Mar 08]. Available from: http://www.escholarship.org/uc/item/80142362.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Christianson DS. Fine-scale Environmental Variation in Mountain Landscapes: Quantitative approaches, influences on tree recruitment, and implications for scientific visualization. [Thesis]. University of California – Berkeley; 2016. Available from: http://www.escholarship.org/uc/item/80142362

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Universiteit Utrecht

9. Gholami Gharasoo, M. Reactive transport simulations of microbial activity and biogeochemical transformations in porous environments - development and application of a pore-network model (Utrecht Studies in Earth Sciences 059).

Degree: 2014, Universiteit Utrecht

URL: http://dspace.library.uu.nl:8080/handle/1874/298612

► The focus of this study was on the development and application of a model, describing the micro-scale, flexible enough to consider any arbitrary number of… (more)

Subjects/Keywords: biodegradation; Pore-network modeling; bioavailability; Spatial heterogeneity; Chemotaxis; Substrate Inhibition

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APA (6^th Edition):

Gholami Gharasoo, M. (2014). Reactive transport simulations of microbial activity and biogeochemical transformations in porous environments - development and application of a pore-network model (Utrecht Studies in Earth Sciences 059). (Doctoral Dissertation). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/298612

Chicago Manual of Style (16^th Edition):

Gholami Gharasoo, M. “Reactive transport simulations of microbial activity and biogeochemical transformations in porous environments - development and application of a pore-network model (Utrecht Studies in Earth Sciences 059).” 2014. Doctoral Dissertation, Universiteit Utrecht. Accessed March 08, 2021. http://dspace.library.uu.nl:8080/handle/1874/298612.

MLA Handbook (7^th Edition):

Gholami Gharasoo, M. “Reactive transport simulations of microbial activity and biogeochemical transformations in porous environments - development and application of a pore-network model (Utrecht Studies in Earth Sciences 059).” 2014. Web. 08 Mar 2021.

Vancouver:

Gholami Gharasoo M. Reactive transport simulations of microbial activity and biogeochemical transformations in porous environments - development and application of a pore-network model (Utrecht Studies in Earth Sciences 059). [Internet] [Doctoral dissertation]. Universiteit Utrecht; 2014. [cited 2021 Mar 08]. Available from: http://dspace.library.uu.nl:8080/handle/1874/298612.

Council of Science Editors:

Gholami Gharasoo M. Reactive transport simulations of microbial activity and biogeochemical transformations in porous environments - development and application of a pore-network model (Utrecht Studies in Earth Sciences 059). [Doctoral Dissertation]. Universiteit Utrecht; 2014. Available from: http://dspace.library.uu.nl:8080/handle/1874/298612

Penn State University

10. Wang, Li. Understanding The Effects Of Mineral Spatial Distributions On Chromium Sorption and Calcite Dissolutoin In Porous Media.

Degree: 2015, Penn State University

URL: https://submit-etda.libraries.psu.edu/catalog/26408

► The study of sorption-desorption and dissolution-precipitation in the natural subsurface is of fundamental interest in many areas of scientiﬁc, industrial and engineering processes, including environmental… (more)

▼ The study of sorption-desorption and dissolution-precipitation in the natural subsurface is of fundamental interest in many areas of scientiﬁc, industrial and engineering processes, including environmental contaminant transport, leaching of agrochemicals from soil surface to groundwater, chemical weathering, enhanced oil or gas recovery and CO2 sequestration. The natural subsurface is highly heterogeneous with minerals distributed in different spatial patterns. Knowledge of how mineral spatial distributions regulate sorption and dissolution processes is important for understanding and modelling the transport and fate of chemicals. However, most published studies about the sorption and dissolution reactions were carried out in well-mixed batch reactors or uniformly packed columns, few data are available on the effects of spatial heterogeneities on the overall reaction rates. The objective of this work is 1) to examine the largely unexplored role of illite spatial distribution patterns in dictating sorption of Cr(VI), a ubiquitously occurring contaminant in Hanford, Oak Ridge, Los Alamos and other sites, 2) to systematically understand and quantify the effects of calcite spatial patterns on its dissolution rates under various reactivity conditions. Flow-through experiments were carried out at 0.1-18.5 m/day using columns packed with the same illite or calcite and quartz mass however with different patterns and permeability contrasts. Two-dimensional reactive transport modeling was used to reproduce the experimental data and to extrapolate the model under a wide range of conditions. For Cr(VI) sorption, at 0.6 and 3.0 m/day, well-connected low permeability illite zone oriented in the flow-parallel direction leads to diffusion-controlled mass transport limitation for accessing sorption sites. This results in up to 1.4 order of magnitude lower macrocapacity and macrorates compared to those in minimally-connected columns with well-mixed illite and quartz. At 15.0 m/day, the eﬀects of spatial heterogeneities are less signiﬁcant (up to a factor of 2.8) owing to the close to chemical kinetics-controlled condition. Additional patterns with the same permeability mean but different 2 lnK (variance of lnK) of 4.5 and 0.2 were generated by Sequential Gaussian Simulation (SGS) at different correlation lengths and column lengths. Sorption capacity and rates decrease with correlation length and transport connectivity, quantitative measures of heterogeneity characteristics. For calcite dissolution, calcite dissolution rates in the 1-zone columns are lower than those in the Mixed columns for all conditions due to the mass transport limitation. The spatial patterns make negligible effects under too low or too high flow velocities due to the equilibrium or kinetic-controlled regimes. At high local dissolution rate conditions (pH <4.0, large surface area or fast dissolving mineral), the “critical” flow region where the effects of spatial heterogeneities are significant is broad and locates at high flow conditions (>10.0 m/d). In… Advisors/Committee Members: Li Li, Dissertation Advisor/Co-Advisor, Li Li, Committee Chair/Co-Chair, Jeffrey Brownson, Committee Member, Eugene C Morgan, Committee Member, Sridhar Komarneni, Committee Member.

Subjects/Keywords: Spatial pattern; Cr(VI) sorption; Dissolution; Heterogeneity; Connectivity; reactive transport

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APA (6^th Edition):

Wang, L. (2015). Understanding The Effects Of Mineral Spatial Distributions On Chromium Sorption and Calcite Dissolutoin In Porous Media. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/26408

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Wang, Li. “Understanding The Effects Of Mineral Spatial Distributions On Chromium Sorption and Calcite Dissolutoin In Porous Media.” 2015. Thesis, Penn State University. Accessed March 08, 2021. https://submit-etda.libraries.psu.edu/catalog/26408.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Wang, Li. “Understanding The Effects Of Mineral Spatial Distributions On Chromium Sorption and Calcite Dissolutoin In Porous Media.” 2015. Web. 08 Mar 2021.

Vancouver:

Wang L. Understanding The Effects Of Mineral Spatial Distributions On Chromium Sorption and Calcite Dissolutoin In Porous Media. [Internet] [Thesis]. Penn State University; 2015. [cited 2021 Mar 08]. Available from: https://submit-etda.libraries.psu.edu/catalog/26408.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wang L. Understanding The Effects Of Mineral Spatial Distributions On Chromium Sorption and Calcite Dissolutoin In Porous Media. [Thesis]. Penn State University; 2015. Available from: https://submit-etda.libraries.psu.edu/catalog/26408

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Toronto

11. John Gnanaraj, Alwish Ranjith. Spatial and Temporal Analysis of Hydraulic Conductivity, Snow Depth and Soil Properties of a Bioretention System.

Degree: 2018, University of Toronto

URL: http://hdl.handle.net/1807/91682

►

Bioretention Cells (BC) are a Low Impact Development technology that provide distributed storm water management near to its source. Most research envisages BC as a… (more)

Subjects/Keywords: Bioretention; Heterogeneity; Hydraulic Conductivity; Soil Properties; Spatial; Temporal; 0543

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APA (6^th Edition):

John Gnanaraj, A. R. (2018). Spatial and Temporal Analysis of Hydraulic Conductivity, Snow Depth and Soil Properties of a Bioretention System. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/91682

Chicago Manual of Style (16^th Edition):

John Gnanaraj, Alwish Ranjith. “Spatial and Temporal Analysis of Hydraulic Conductivity, Snow Depth and Soil Properties of a Bioretention System.” 2018. Masters Thesis, University of Toronto. Accessed March 08, 2021. http://hdl.handle.net/1807/91682.

MLA Handbook (7^th Edition):

John Gnanaraj, Alwish Ranjith. “Spatial and Temporal Analysis of Hydraulic Conductivity, Snow Depth and Soil Properties of a Bioretention System.” 2018. Web. 08 Mar 2021.

Vancouver:

John Gnanaraj AR. Spatial and Temporal Analysis of Hydraulic Conductivity, Snow Depth and Soil Properties of a Bioretention System. [Internet] [Masters thesis]. University of Toronto; 2018. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/1807/91682.

Council of Science Editors:

John Gnanaraj AR. Spatial and Temporal Analysis of Hydraulic Conductivity, Snow Depth and Soil Properties of a Bioretention System. [Masters Thesis]. University of Toronto; 2018. Available from: http://hdl.handle.net/1807/91682

Universidade Nova

12. Duce, Stephanie Jane. Microtheories for SDI - Accounting for diversity of local conceptualisations at a global level.

Degree: 2009, Universidade Nova

URL: http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/8252

►

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

The categorization and conceptualization of geographic features… (more)

Subjects/Keywords: Microtheories SDI; Cartography; Semantic heterogeneity; Spatial Data; Infrastructures

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APA (6^th Edition):

Duce, S. J. (2009). Microtheories for SDI - Accounting for diversity of local conceptualisations at a global level. (Thesis). Universidade Nova. Retrieved from http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/8252

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Duce, Stephanie Jane. “Microtheories for SDI - Accounting for diversity of local conceptualisations at a global level.” 2009. Thesis, Universidade Nova. Accessed March 08, 2021. http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/8252.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Duce, Stephanie Jane. “Microtheories for SDI - Accounting for diversity of local conceptualisations at a global level.” 2009. Web. 08 Mar 2021.

Vancouver:

Duce SJ. Microtheories for SDI - Accounting for diversity of local conceptualisations at a global level. [Internet] [Thesis]. Universidade Nova; 2009. [cited 2021 Mar 08]. Available from: http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/8252.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Duce SJ. Microtheories for SDI - Accounting for diversity of local conceptualisations at a global level. [Thesis]. Universidade Nova; 2009. Available from: http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/8252

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

RMIT University

13. Hannam, J. Homogeneity and Heterogeneity: two approaches for designing spatial sound.

Degree: 2013, RMIT University

URL: http://researchbank.rmit.edu.au/view/rmit:160555

► My research explores the process for designing and reproducing spatial sound through two personal sound-design projects: Pilate (2006) and Metamorphosis42 (2009). Located within the context… (more)

▼ My research explores the process for designing and reproducing spatial sound through two personal sound-design projects: Pilate (2006) and Metamorphosis42 (2009). Located within the context of design, it explores two modes for spatial sound composition, which at its heart contemplates the potential for the phenomenon of the sound experience to guide the design and reproduction of spatial sound using electroacoustic techniques. The intent is to convey an approach to sound design, by combining the concepts with the tools and techniques used in sound composition, to create an impression of space that is perceived by the listener. This process has enabled me to draw a distinction in approach between my projects, based on the concepts, tools and techniques I apply in the act of making, to guide my work. In emphasising the sound space relation, the notions of the ‘homogeneous’ and the ‘heterogeneous’ emerge. I apply these terms in my research, to embody the essence of a compositional methodology, explored through an analysis of my projects and by engaging with a process of reflection and listening. On this basis, my research suggests that the notion of the ‘homogeneous’ builds on the physical relations of sound and space through an experience of sound within space. If our experience of sound in a real-world scenario can be considered coherent, then, in the context of a sound design process, my research proposes that a ‘homogeneous’ approach to sound composition seeks to faithfully reproduce the perceptually coherent sounding qualities observed in the real-world. This approach is predicated on the fact that the sensations of sound are the result of vibrating materials. The displacement, which occurs at the material surface, creates a pressure wave that moves through the atmosphere interacting with other materials within the environment. As a consequence, the pressure waves that reach our ears come from all directions, not just one and the physical qualities of the materials the pressure wave interacts with – their size, shape and density, for example, directly influence how sound is perceived. The notion of the ‘heterogeneous’ builds on the internal relation of sound and space - the space within sound, and how the physical and imagined qualities of space are interchangeable which conveys a dynamic and complex sense of space. A quality of this approach is that sound is suspended in its own time and space through a poetic re-imagination - an interior space in which sound is decoupled from its physical source. As François Bayle (2007, p.241) writes, ‘a sound from a transducer is like no other’. I interpret this as a way to think about the reproduced sound, which sits beyond the physical. I use the term ‘re-imagination’ to emphasise that the listener is not passive, but instead an active body engaged in this contemplation of sound. On this basis, the heterogeneous…

Subjects/Keywords: Fields of Research; Design; Spatial sound; Composition; Homogeneity; Heterogeneity

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APA (6^th Edition):

Hannam, J. (2013). Homogeneity and Heterogeneity: two approaches for designing spatial sound. (Thesis). RMIT University. Retrieved from http://researchbank.rmit.edu.au/view/rmit:160555

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Hannam, J. “Homogeneity and Heterogeneity: two approaches for designing spatial sound.” 2013. Thesis, RMIT University. Accessed March 08, 2021. http://researchbank.rmit.edu.au/view/rmit:160555.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Hannam, J. “Homogeneity and Heterogeneity: two approaches for designing spatial sound.” 2013. Web. 08 Mar 2021.

Vancouver:

Hannam J. Homogeneity and Heterogeneity: two approaches for designing spatial sound. [Internet] [Thesis]. RMIT University; 2013. [cited 2021 Mar 08]. Available from: http://researchbank.rmit.edu.au/view/rmit:160555.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Hannam J. Homogeneity and Heterogeneity: two approaches for designing spatial sound. [Thesis]. RMIT University; 2013. Available from: http://researchbank.rmit.edu.au/view/rmit:160555

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Toronto

14. Polakowska, Aleksandra. Quantifying the Spatial Relationship between Landcover Hheterogeneity and Species' Distributions.

Degree: 2010, University of Toronto

URL: http://hdl.handle.net/1807/24275

►

Although considerable research has been invested in disentangling the factors limiting species’ ranges at local and continental spatial scales, less attention has been granted to… (more)

Subjects/Keywords: boundary analysis; species range; birds; spatial heterogeneity; conservation; Ontario; 0329

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APA (6^th Edition):

Polakowska, A. (2010). Quantifying the Spatial Relationship between Landcover Hheterogeneity and Species' Distributions. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/24275

Chicago Manual of Style (16^th Edition):

Polakowska, Aleksandra. “Quantifying the Spatial Relationship between Landcover Hheterogeneity and Species' Distributions.” 2010. Masters Thesis, University of Toronto. Accessed March 08, 2021. http://hdl.handle.net/1807/24275.

MLA Handbook (7^th Edition):

Polakowska, Aleksandra. “Quantifying the Spatial Relationship between Landcover Hheterogeneity and Species' Distributions.” 2010. Web. 08 Mar 2021.

Vancouver:

Polakowska A. Quantifying the Spatial Relationship between Landcover Hheterogeneity and Species' Distributions. [Internet] [Masters thesis]. University of Toronto; 2010. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/1807/24275.

Council of Science Editors:

Polakowska A. Quantifying the Spatial Relationship between Landcover Hheterogeneity and Species' Distributions. [Masters Thesis]. University of Toronto; 2010. Available from: http://hdl.handle.net/1807/24275

University of Iowa

15. Zahrieh, David. Bayesian point process modeling to quantify excess risk in spatial epidemiology: an analysis of stillbirths with a maternal contextual effect.

Degree: PhD, Biostatistics, 2017, University of Iowa

URL: https://ir.uiowa.edu/etd/5884

► Motivated by the paucity of high quality stillbirth surveillance data and the spatial analyses of such data, the current research sets out to quantitatively… (more)

▼ Motivated by the paucity of high quality stillbirth surveillance data and the spatial analyses of such data, the current research sets out to quantitatively describe the pattern of stillbirth events that may lead to mechanistic hypotheses. We broaden the appeal of Bayesian Poisson point process modeling to quantify excess risk while accounting for unobserved heterogeneity. We consider a practical data analysis strategy when fitting the point process model and study the utility of parameterizing the intensity function governing the point process to include a maternal contextual effect to account for variation due to multiple stillbirth events experienced by the same mother in independent pregnancies. Simulation studies suggest that our practical data analysis strategy is reasonable and that there is a variance-bias trade-off associated with the use of a maternal contextual effect. The methodology is applied to the spatial distribution of stillbirth events in Iowa during the years 2005 through 2011 obtained using an active, statewide public health surveillance approach. Several localized areas of excess risk were identified and mapped based on model components that captured the nuanced and salient features of the data. A conditional formulation of the point process model is then considered, which has two main advantages: the ability to easily incorporate covariate information attached to both stillbirth and live birth, as well as obviate the need to estimate the background intensity. We assess the utility of the conditional approach in the presence of unobserved heterogeneity, compare two Bayesian estimation techniques, and extend the conditional formulation to adequately capture spatio-temporal effects. The motivating study comes from the Iowa Registry for Congenital and Inherited Disorders who has a committed interest in the surveillance and epidemiology of stillbirth in Iowa and whether the occurrence might be geographically linked. Advisors/Committee Members: Oleson, Jacob J. (supervisor).

Subjects/Keywords: Bayesian; Contextual Effect; Point Process; Spatial Heterogeneity; Biostatistics

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APA (6^th Edition):

Zahrieh, D. (2017). Bayesian point process modeling to quantify excess risk in spatial epidemiology: an analysis of stillbirths with a maternal contextual effect. (Doctoral Dissertation). University of Iowa. Retrieved from https://ir.uiowa.edu/etd/5884

Chicago Manual of Style (16^th Edition):

Zahrieh, David. “Bayesian point process modeling to quantify excess risk in spatial epidemiology: an analysis of stillbirths with a maternal contextual effect.” 2017. Doctoral Dissertation, University of Iowa. Accessed March 08, 2021. https://ir.uiowa.edu/etd/5884.

MLA Handbook (7^th Edition):

Zahrieh, David. “Bayesian point process modeling to quantify excess risk in spatial epidemiology: an analysis of stillbirths with a maternal contextual effect.” 2017. Web. 08 Mar 2021.

Vancouver:

Zahrieh D. Bayesian point process modeling to quantify excess risk in spatial epidemiology: an analysis of stillbirths with a maternal contextual effect. [Internet] [Doctoral dissertation]. University of Iowa; 2017. [cited 2021 Mar 08]. Available from: https://ir.uiowa.edu/etd/5884.

Council of Science Editors:

Zahrieh D. Bayesian point process modeling to quantify excess risk in spatial epidemiology: an analysis of stillbirths with a maternal contextual effect. [Doctoral Dissertation]. University of Iowa; 2017. Available from: https://ir.uiowa.edu/etd/5884

University of Colorado

16. Tea, Kallin. Causes and Consequences of Fine Scale Spatial Heterogeneity of Soil Nutrients.

Degree: PhD, Ecology & Evolutionary Biology, 2014, University of Colorado

URL: https://scholar.colorado.edu/ebio_gradetds/53

► As an environment changes over time, pedogenesis influences the amount of soil nutrients available to plants. The effect of long term soil development on… (more)

Subjects/Keywords: biogeochemistry; chronosequence; coexistence; community; invasion; spatial heterogeneity; Plant Sciences; Soil Science

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APA (6^th Edition):

Tea, K. (2014). Causes and Consequences of Fine Scale Spatial Heterogeneity of Soil Nutrients. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/ebio_gradetds/53

Chicago Manual of Style (16^th Edition):

Tea, Kallin. “Causes and Consequences of Fine Scale Spatial Heterogeneity of Soil Nutrients.” 2014. Doctoral Dissertation, University of Colorado. Accessed March 08, 2021. https://scholar.colorado.edu/ebio_gradetds/53.

MLA Handbook (7^th Edition):

Tea, Kallin. “Causes and Consequences of Fine Scale Spatial Heterogeneity of Soil Nutrients.” 2014. Web. 08 Mar 2021.

Vancouver:

Tea K. Causes and Consequences of Fine Scale Spatial Heterogeneity of Soil Nutrients. [Internet] [Doctoral dissertation]. University of Colorado; 2014. [cited 2021 Mar 08]. Available from: https://scholar.colorado.edu/ebio_gradetds/53.

Council of Science Editors:

Tea K. Causes and Consequences of Fine Scale Spatial Heterogeneity of Soil Nutrients. [Doctoral Dissertation]. University of Colorado; 2014. Available from: https://scholar.colorado.edu/ebio_gradetds/53

University of Toronto

17. Leng, Jiye. Downscaling the Maximum Carboxylation Rate (Vcmax) Derived from Satellite Sun-induced Chlorophyll Fluorescence Data Using High-resolution Remote Sensing Products.

Degree: 2020, University of Toronto

URL: http://hdl.handle.net/1807/103407

►

The maximum carboxylation rate (Vcmax) influences the magnitude of gross primary productivity (GPP). Currently, reliable global Vcmax products derived from satellite sun-induced chlorophyll fluorescence (SIF)… (more)

Subjects/Keywords: Downscaling; Global Carbon Cycle; Maximum Carboxylation Rate; Spatial Heterogeneity; Vcmax25; 0366

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APA (6^th Edition):

Leng, J. (2020). Downscaling the Maximum Carboxylation Rate (Vcmax) Derived from Satellite Sun-induced Chlorophyll Fluorescence Data Using High-resolution Remote Sensing Products. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/103407

Chicago Manual of Style (16^th Edition):

Leng, Jiye. “Downscaling the Maximum Carboxylation Rate (Vcmax) Derived from Satellite Sun-induced Chlorophyll Fluorescence Data Using High-resolution Remote Sensing Products.” 2020. Masters Thesis, University of Toronto. Accessed March 08, 2021. http://hdl.handle.net/1807/103407.

MLA Handbook (7^th Edition):

Leng, Jiye. “Downscaling the Maximum Carboxylation Rate (Vcmax) Derived from Satellite Sun-induced Chlorophyll Fluorescence Data Using High-resolution Remote Sensing Products.” 2020. Web. 08 Mar 2021.

Vancouver:

Leng J. Downscaling the Maximum Carboxylation Rate (Vcmax) Derived from Satellite Sun-induced Chlorophyll Fluorescence Data Using High-resolution Remote Sensing Products. [Internet] [Masters thesis]. University of Toronto; 2020. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/1807/103407.

Council of Science Editors:

Leng J. Downscaling the Maximum Carboxylation Rate (Vcmax) Derived from Satellite Sun-induced Chlorophyll Fluorescence Data Using High-resolution Remote Sensing Products. [Masters Thesis]. University of Toronto; 2020. Available from: http://hdl.handle.net/1807/103407

18. Mahdipour Shirayeh, Ali. Evolutionary Dynamics of Cancer: Spatial and Heterogeneous Effects.

Degree: 2017, University of Waterloo

URL: http://hdl.handle.net/10012/11240

► Despite significant advances in the study of cancer and associated combination therapeutic treatments, cancer still remains one of the most common and complex often-terminal diseases.… (more)

▼ Despite significant advances in the study of cancer and associated combination therapeutic treatments, cancer still remains one of the most common and complex often-terminal diseases. Acquisition of high-throughput experimental data from diverse cellular perspectives has thrown light on some of the regulatory mechanisms underlying the development of cancer. However, in general there is a lack of a general pattern and coherent model which can explain the development and evolution of the disease. To this end, evolutionary dynamics has been used, as a mathematical tool, in numerous studies to model various aspects of cancer over time periods. Our main focus in this thesis is on the use of stochastic and statistic methods to study cellular interactions within cancer tissues in order to understand the role of spatial structure, heterogeneity, and the microenvironment in cancer development. By constructing multi-cellular structures and using both analytic calculations and stochastic simulations, we have investigated the phenotypic hierarchy of stem cells within a heterogeneous system and in the presence of environmentally induced plasticity. Moreover, the effect of a random environment on the development of cancer has been explored in a general framework. As an important application of the multi-stage hierarchical model, the structure of the colonic/intestinal crypt has been taken into account to show the crucial role of these stem cells in the initiation and progression of colorectal/intestinal cancer. From an alternative viewpoint, we have envisaged the hierarchy of mutations as an evolutionary mechanism in the context of acute myeloid leukemia and carried out a statistical analysis of genetic data. Our findings in this thesis are general and most likely have many implications across a wide array of fields including different blood and solid cancers, bacterial growth, drug resistance and social networks. Moreover, the introduced methods and analyses should have important applications in diverse branches of evolution, ecology, and population genetics.

Subjects/Keywords: Evolutionary dynamics; Cancer; Dynamical system; Heterogeneity; Spatial structure; Random environment

11 more images…

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APA (6^th Edition):

Mahdipour Shirayeh, A. (2017). Evolutionary Dynamics of Cancer: Spatial and Heterogeneous Effects. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/11240

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Mahdipour Shirayeh, Ali. “Evolutionary Dynamics of Cancer: Spatial and Heterogeneous Effects.” 2017. Thesis, University of Waterloo. Accessed March 08, 2021. http://hdl.handle.net/10012/11240.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Mahdipour Shirayeh, Ali. “Evolutionary Dynamics of Cancer: Spatial and Heterogeneous Effects.” 2017. Web. 08 Mar 2021.

Vancouver:

Mahdipour Shirayeh A. Evolutionary Dynamics of Cancer: Spatial and Heterogeneous Effects. [Internet] [Thesis]. University of Waterloo; 2017. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/10012/11240.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Mahdipour Shirayeh A. Evolutionary Dynamics of Cancer: Spatial and Heterogeneous Effects. [Thesis]. University of Waterloo; 2017. Available from: http://hdl.handle.net/10012/11240

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Virginia Tech

19. Selin, Steven J. Soil Heterogeneity Changes During Forest Succession: Test of a Model Using Univariate and Geostatistics.

Degree: MS, Forestry, 2002, Virginia Tech

URL: http://hdl.handle.net/10919/32485

► We sampled forest stands in upland forests of the Southeastern US along a chronosequence of a replicated successional forest sere (1, 6, 10, 25, and… (more)

Subjects/Keywords: soil; nutrient; heterogeneity; spatial; disturbance

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Selin, S. J. (2002). Soil Heterogeneity Changes During Forest Succession: Test of a Model Using Univariate and Geostatistics. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/32485

Chicago Manual of Style (16^th Edition):

Selin, Steven J. “Soil Heterogeneity Changes During Forest Succession: Test of a Model Using Univariate and Geostatistics.” 2002. Masters Thesis, Virginia Tech. Accessed March 08, 2021. http://hdl.handle.net/10919/32485.

MLA Handbook (7^th Edition):

Selin, Steven J. “Soil Heterogeneity Changes During Forest Succession: Test of a Model Using Univariate and Geostatistics.” 2002. Web. 08 Mar 2021.

Vancouver:

Selin SJ. Soil Heterogeneity Changes During Forest Succession: Test of a Model Using Univariate and Geostatistics. [Internet] [Masters thesis]. Virginia Tech; 2002. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/10919/32485.

Council of Science Editors:

Selin SJ. Soil Heterogeneity Changes During Forest Succession: Test of a Model Using Univariate and Geostatistics. [Masters Thesis]. Virginia Tech; 2002. Available from: http://hdl.handle.net/10919/32485

20. Kang, Dongwoo. Essays on Spatial Externality and Spatial Heterogeneity in Applied Spatial Econometrics .

Degree: 2015, University of Arizona

URL: http://hdl.handle.net/10150/560840

► This dissertation consists of three empirical essays of which contributions consist, first, in developing spatial weight matrices based on more than just pure geographical proximity… (more)

▼ This dissertation consists of three empirical essays of which contributions consist, first, in developing spatial weight matrices based on more than just pure geographical proximity for the modeling of interregional externalities. Second, my essays propose different approaches to discover spatial heterogeneity in the data generating processes, including the interregional externalities, under investigation. This dissertation provides Economic Geographers and Regional Scientists interested in the modeling and measurement of spatial externalities a set of practical examples based on new datasets and state-of-the-art spatial econometric techniques to consider for their own work. I hope my dissertation will provide them with some guidance on how various aspects of spatial externalities can be incorporated in traditional spatial weight matrices and of how much the impact of externalities can be spatially heterogeneous. The results of the dissertation should help spatial and regional policy makers to understand better various aspects of interregional dependence in regional economic systems and to devise locally effective and place-tailored spatial and regional policies. The first essay investigates the negative spatial externalities of irrigation on corn production. The spatial externalities of irrigation water are well known but have never been examined in a spatial econometric framework so far. We investigate their role in a theoretical model of profit-maximizing farming and verify our predictions empirically in a crop production function measured across US Corn Belt counties. The interregional groundwater and surface water externalities are modeled based on actual aquifer and river stream network characteristics. The second essay examines the positive spatial externalities of academic and private R&D spending in the frame of a regional knowledge production function measured across US counties. It distinguishes the role of local knowledge spillovers that are determined by geographical proximity from distant spillovers that we choose to capture through a matrix of patent creation-citation flows. The advantage of the latter matrix is its capacity to capture the technological proximity between counties as well as the direction of knowledge spillovers. These two elements have been missed in the literature so far. The last essay highlights and measures the presence of spatial heterogeneity in the marginal effect of the innovation inputs, more especially of the interregional knowledge spillovers. The literature of knowledge production function has adopted geographically aggregated units and controlled for region-specific conditions to highlight the presence of spatial heterogeneity in regional knowledge creation. However, most empirical studies have relied on a global modeling approach that measures spatially homogenous marginal effects of knowledge inputs. This essay explains the source of the heterogeneity in innovation and then measures the spatial heterogeneity in the marginal effects of knowledge spillovers as well as of… Advisors/Committee Members: Dall'erba, Sandy (advisor), Hirano, Keisuke (committeemember), Plane, David A. (committeemember), Tong, Daoqin (committeemember), Dall'erba, Sandy (committeemember).

Subjects/Keywords: Spatial Externality; Spatial Heterogeneity; Geography; Spatial Econometrics

…82 CHAPTER 4. SPATIAL HETEROGENEITY IN SPATIAL EXTERNALITY: EXPLORING THE SPATIAL… …88 4.2.1 Sources of Spatial Heterogeneity in Knowledge Creation and Innovation ..... 88… …4.2.2 Modeling Spatial Heterogeneity in the Empirical Studies of Knowledge Production Function… …different approaches to discover spatial heterogeneity in the data generating processes, including… …essay explains the source of the heterogeneity in innovation and then measures the spatial…

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APA (6^th Edition):

Kang, D. (2015). Essays on Spatial Externality and Spatial Heterogeneity in Applied Spatial Econometrics . (Doctoral Dissertation). University of Arizona. Retrieved from http://hdl.handle.net/10150/560840

Chicago Manual of Style (16^th Edition):

Kang, Dongwoo. “Essays on Spatial Externality and Spatial Heterogeneity in Applied Spatial Econometrics .” 2015. Doctoral Dissertation, University of Arizona. Accessed March 08, 2021. http://hdl.handle.net/10150/560840.

MLA Handbook (7^th Edition):

Kang, Dongwoo. “Essays on Spatial Externality and Spatial Heterogeneity in Applied Spatial Econometrics .” 2015. Web. 08 Mar 2021.

Vancouver:

Kang D. Essays on Spatial Externality and Spatial Heterogeneity in Applied Spatial Econometrics . [Internet] [Doctoral dissertation]. University of Arizona; 2015. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/10150/560840.

Council of Science Editors:

Kang D. Essays on Spatial Externality and Spatial Heterogeneity in Applied Spatial Econometrics . [Doctoral Dissertation]. University of Arizona; 2015. Available from: http://hdl.handle.net/10150/560840

Addis Ababa University

21. Tadesse, Sebsibe. The Spatial Epidemiology of Tuberculosis in Gurage Zone, Southern Ethiopia.

Degree: 2018, Addis Ababa University

URL: http://10.6.20.92/handle/123456789/20898

► Background: The global distribution of tuberculosis is skewed heavily toward low-and-middle income countries, which accounted for about 87% of all estimated incident cases. Ethiopia is… (more)

▼ Background: The global distribution of tuberculosis is skewed heavily toward low-and-middle income countries, which accounted for about 87% of all estimated incident cases. Ethiopia is a low-income country in east Africa that remains highly afflicted by tuberculosis, with varying degrees of magnitudes across settings. However, there is a dearth of studies clarifying about the spatial epidemiology of the disease in Ethiopia. Lack of such information may contribute to the partial effectiveness of tuberculosis control programs. Objectives: The specific objectives of this study were: 1) to detect spatial and space-time clustering of tuberculosis, 2) to estimate spatial risk of tuberculosis distribution using limited spatial datasets, and 3) to identify ecological factors affecting spatial distribution of tuberculosis in Gurage Zone, Southern Ethiopia. Methods: The study data were obtained from different sources. Specific objectives 1 and 3 included a total of 15,805 tuberculosis patients diagnosed at health facilities in Gurage Zone during 2007 to 2016, whereas specific objective 2 included 1,601 patients diagnosed in 2016. The geo-location and population data were obtained from the Central Statistical Agency of Ethiopia (specific objectives 1-3). The altitude data were extracted from global digital elevation model v2 (specific objective 2). The normalized difference vegetation index data were derived from the moderate resolution imaging spectroradiometer imagery, and the temperature and rainfall data were obtained from the Meteorological Agency of Ethiopia (specific objective 3). The global Moran’s I, Kulldorff’s scan and Getis-Ord statistics were used to analyze purely spatial and space-time clustering of tuberculosis (specific objective 1). The geostatistical kriging approach was applied to estimate the spatial risk of tuberculosis distribution (specific objective 2). The spatial panel data analysis was used to estimate the effects of ecological factors on spatial distribution of tuberculosis prevalence rate (specific objective 3). Results: The prevalence of tuberculosis varied from 70.4 to 155.3 cases per 100,000 population in the Gurage Zone during 2007 to 2016. Eleven purely spatial clusters (relative risk: 1.36–14.52, P-value < 0.001) and three space-time clusters (relative risk: 1.46–2.01, P-value < 0.001) for high occurrence of tuberculosis were detected. The clusters were mainly concentrated in border areas of the zone. The predictive accuracies of ordinary cokriging models have improved with the inclusion of anisotropy, altitude and latitude covariates, the change in detrending pattern from local to global, and the increase in size of spatial dataset (mean-standardized error = 0, rootxi mean-square-standardized error = 1, and average-standard error ≈ root-mean-square error). The spatial risk of tuberculosis was estimated to be higher (i.e., tuberculosis prevalence rate > 100 cases per 100,000 population) at western, northwest, southwest and southeast parts of the study area,… Advisors/Committee Members: Enqueselassie, Fikre(PHD) (advisor), Hagos, Seifu (PHD) (advisor).

Subjects/Keywords: Ecological factors; Geostatistical kriging approach; Purely spatial clusters; Spacetime clusters; Spatial autocorrelation; Spatial epidemiology; Spatial heterogeneity; Spatial panel data analysis; Tuberculosis distribution

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Tadesse, S. (2018). The Spatial Epidemiology of Tuberculosis in Gurage Zone, Southern Ethiopia. (Thesis). Addis Ababa University. Retrieved from http://10.6.20.92/handle/123456789/20898

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Tadesse, Sebsibe. “The Spatial Epidemiology of Tuberculosis in Gurage Zone, Southern Ethiopia. ” 2018. Thesis, Addis Ababa University. Accessed March 08, 2021. http://10.6.20.92/handle/123456789/20898.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Tadesse, Sebsibe. “The Spatial Epidemiology of Tuberculosis in Gurage Zone, Southern Ethiopia. ” 2018. Web. 08 Mar 2021.

Vancouver:

Tadesse S. The Spatial Epidemiology of Tuberculosis in Gurage Zone, Southern Ethiopia. [Internet] [Thesis]. Addis Ababa University; 2018. [cited 2021 Mar 08]. Available from: http://10.6.20.92/handle/123456789/20898.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Tadesse S. The Spatial Epidemiology of Tuberculosis in Gurage Zone, Southern Ethiopia. [Thesis]. Addis Ababa University; 2018. Available from: http://10.6.20.92/handle/123456789/20898

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

22. Lopez, Juan Carlos. Essays in Urban Economics, Economic Geography and Water.

Degree: Economics, 2016, University of California – Riverside

URL: http://www.escholarship.org/uc/item/60s310dg

► This study has two primary focuses. The first is on the uneven distribution of high quality land across space. Of particular interest is how the… (more)

▼ This study has two primary focuses. The first is on the uneven distribution of high quality land across space. Of particular interest is how the spatial heterogeneity of land affects the location of households across regions, the development of land for urban and agricultural purposes within regions and the spatial structure of urban land use patterns within a given city. A second focus is how interbasin water transfers, which ameliorate the uneven distribution of water across regions, affect inter and intraregional land-use patterns. More specifically, the question this research asks is, what are the consequences of water transfers across regions when the preferences of households and the productivity of agricultural appears to favor the land in arid locations? And when land quality varies spatially, how does that alter the development patterns of cities and regions generally?This research develops a framework for analyzing the implications of interbasin water transfers on interregional migration and intraregional land use patterns. The model employed in Chapter 2 is a novel synthesis of the two dominant models in the urban economics literature, namely, the two region core-periphery model and the monocetric city model. However the model is modified to account for spatial disparities in the quality of land across regions. In particular, a scenario is explored where one region has a greater degree of natural amenities and thus, ceteris paribus, is preferred by households, as well as a comparative advantage in agricultural production. In addition, there are agglomeration externalities in the urban labor force, which, if sufficiently strong, leads to a concentration of all households in a single region. A second modification is that the more attractive region lacks water resources and, in order to satisfy household and agricultural water demand, must import water from the other region. This setup focuses on the tension between what is termed the amenity premium for households and the productivity premium for the agricultural sector, both of which compete for land in the same region. Chapter 3 introduces public infrastructure into the previous model. The infrastructure, which is endogenous and defined by the demand for water in each region, is financed through a flat tax. In addition, we consider that there are transport costs in the distribution of agricultural output across regions. This assumption allows for three different trade regimes. Autarky, in which each region produces agriculture solely for the local population. Incomplete specialization, in which the more productive region produces all local supply and any excess is sold to the other region to supplement local output. Complete specialization, where all agricultural production is concentrated in a single region.Chapter 4 turns to the issue of the heterogeneity in the quality of land within cities. The monocentric city modeling framework has developed a robust specification of urban spatial structure. In particular, it has shown how commuting…

Subjects/Keywords: Economics; Water resources management; Economic Geography; Land use; Spatial Heterogeneity; water use

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APA (6^th Edition):

Lopez, J. C. (2016). Essays in Urban Economics, Economic Geography and Water. (Thesis). University of California – Riverside. Retrieved from http://www.escholarship.org/uc/item/60s310dg

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Lopez, Juan Carlos. “Essays in Urban Economics, Economic Geography and Water.” 2016. Thesis, University of California – Riverside. Accessed March 08, 2021. http://www.escholarship.org/uc/item/60s310dg.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Lopez, Juan Carlos. “Essays in Urban Economics, Economic Geography and Water.” 2016. Web. 08 Mar 2021.

Vancouver:

Lopez JC. Essays in Urban Economics, Economic Geography and Water. [Internet] [Thesis]. University of California – Riverside; 2016. [cited 2021 Mar 08]. Available from: http://www.escholarship.org/uc/item/60s310dg.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Lopez JC. Essays in Urban Economics, Economic Geography and Water. [Thesis]. University of California – Riverside; 2016. Available from: http://www.escholarship.org/uc/item/60s310dg

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

23. Silva, Sheila Cardoso da. Heterogeneidade espacial e a qualidade das águas superficiais do Reservatório Guarapiranga (São Paulo-SP-Brasil).

Degree: Mestrado, Ecologia: Ecossistemas Terrestres e Aquáticos, 2008, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/41/41134/tde-16012009-145435/ ;

►

O estudo da heterogeneidade ambiental é de fundamental importância em ecologia, uma vez que interfere na estrutura e funcionamento dos ecossistemas. Reservatórios em particular são… (more)

▼

O estudo da heterogeneidade ambiental é de fundamental importância em ecologia, uma vez que interfere na estrutura e funcionamento dos ecossistemas. Reservatórios em particular são ecossistemas artificiais com alto grau de heterogeneidade espacial e temporal. Com intuito de testar a hipótese da existência de um padrão de heterogeneidade nas águas superficiais do reservatório Guarapiranga e discutir a qualidade de suas águas, com base na resolução CONAMA 357/05, foram efetuadas coletas, durante as estações seca e chuvosa, de variáveis físicas, químicas e hidrobiológicas, em 33 estações distribuídas ao longo da represa Guarapiranga. Os dados foram analisados por meio de Análise de Componentes Principais (ACP) e os resultados corroboraram a hipótese testada. Foi possível identificar quatro compartimentos: 1) um compartimento localizado na região da entrada do córrego de Parelheiros, com características de zona fluvial; 2) um compartimento na região do braço da represa Guarapiranga onde ocorre a entrada do Rio Embu-Guaçu, local em que foram observados os menores valores para condutividade elétrica, sólidos totais, fósforo total, nitrogênio total e material particulado em suspensão; 3) um compartimento com características de zona de transição, o qual tendeu a ser mais prolongado na campanha da estação chuvosa, provavelmente pelo regime de operação do reservatório, que apresenta maior vazão no período das cheias; 4) um compartimento na região jusante, onde foram observados os maiores valores para disco de Secchi, maiores concentrações de nitrogênio total, maior participação da fração orgânica do material em suspensão, sólidos totais e pH; estes dados são provavelmente resultados da grande urbanização observada ao redor do reservatório e do maior tempo de retenção na área da barragem. Foi observada também condição mais crítica da qualidade da água na região de Parelheiros. Além disso, as concentrações de: fósforo total, clorofila a, oxigênio dissolvido e cádmio total, apresentaram-se fora das metas estabelecidas para os corpos hídricos classe 1, no qual a represa Guarapiranga foi enquadrada. Tais dados apontam para a necessidade do controle das ocupações irregulares, e da implantação de rede coletora de esgotos na bacia Guarapiranga.

Environmental heterogeneity studies are of great importance in ecology, once it interferes on ecosystems structure and working. Water reservoirs in particular are artificial ecosystems with high spatial and temporal heterogeneity. To test the hypothesis of existence of a pattern of longitudinal heterogeneity, and discuss water quality according to CONAMA 357/05, samples of physical, chemical and hydrobiological variables were collected during the dry and wet seasons in 33 stations in the Guarapiranga reservoir. Data were analysed by Principal Components Analisys (PCA) and the results corroborated the tested hypothesis. It was possible to identify four compartments: 1) a compartment near the entrance of Parelheiros streamlet, with riverine characteristics; 2) a compartment on the area of…

Advisors/Committee Members: Pompeo, Marcelo Luiz Martins.

Subjects/Keywords: Guarapiranga reservoir; Heterogeneidade espacial; Qualidade da água; Reservatório Guarapiranga; Spatial heterogeneity; Water quality

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APA (6^th Edition):

Silva, S. C. d. (2008). Heterogeneidade espacial e a qualidade das águas superficiais do Reservatório Guarapiranga (São Paulo-SP-Brasil). (Masters Thesis). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/41/41134/tde-16012009-145435/ ;

Chicago Manual of Style (16^th Edition):

Silva, Sheila Cardoso da. “Heterogeneidade espacial e a qualidade das águas superficiais do Reservatório Guarapiranga (São Paulo-SP-Brasil).” 2008. Masters Thesis, University of São Paulo. Accessed March 08, 2021. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-16012009-145435/ ;.

MLA Handbook (7^th Edition):

Silva, Sheila Cardoso da. “Heterogeneidade espacial e a qualidade das águas superficiais do Reservatório Guarapiranga (São Paulo-SP-Brasil).” 2008. Web. 08 Mar 2021.

Vancouver:

Silva SCd. Heterogeneidade espacial e a qualidade das águas superficiais do Reservatório Guarapiranga (São Paulo-SP-Brasil). [Internet] [Masters thesis]. University of São Paulo; 2008. [cited 2021 Mar 08]. Available from: http://www.teses.usp.br/teses/disponiveis/41/41134/tde-16012009-145435/ ;.

Council of Science Editors:

Silva SCd. Heterogeneidade espacial e a qualidade das águas superficiais do Reservatório Guarapiranga (São Paulo-SP-Brasil). [Masters Thesis]. University of São Paulo; 2008. Available from: http://www.teses.usp.br/teses/disponiveis/41/41134/tde-16012009-145435/ ;

Universiteit Utrecht

24. Leng, C.C. The Effect of Spatial Correlation on Viscous Fingering in a Dynamic Pore-Network Model with Delaunay Tessellated Structure.

Degree: 2013, Universiteit Utrecht

URL: http://dspace.library.uu.nl:8080/handle/1874/279850

► The formation of viscous fingers is a well known and often unwanted (e.g. in oil recovery) effect in porous systems with fluids of different viscosities.… (more)

▼ The formation of viscous fingers is a well known and often unwanted (e.g. in oil recovery) effect in porous systems with fluids of different viscosities. In this study viscous fingering is studied with a dynamic pore-network model using Delaunay tessellated networks. The pore size distribution is modeled as a correlated random field with varying correlation length. We focus on the effect of correlation length on viscous fingering. The topologically disordered networks are generated using a network generator which is developed in this work. The parameters are based on a Berea sandstone sample network. Analysis on the produced networks found that they are roughly in agreement with input parameters, and that they are statistically similar. Because of the stochastic nature of the network generation, three network realizations were produced for four different correlation lengths for the simulations, so that averaging can be applied. Using these networks drainage simulations were performed, with a viscosity ratio M = 0.1 to allow viscous fingering. We found that viscous fingering effects increased with increasing correlation length. This was most apparent at the initial stages of the simulations, at low global saturations. The fingering zone is suggested to be affected by correlation length, i.e., the correlation length is suggested to correlate inversely with the amount of fingers and the density of the invading fluid in the fingering zone, and positively with finger length and the size of the fingering zone. These effects cause a reversal in the order of the tails of the saturation profiles at higher global saturations. Additionally, breakthrough profiles were constructed, which provide more evidence on enhanced viscous fingering with increasing correlation length. However, at large correlation lengths results start to act erratic. Fingering patterns were also visualized; the evolution in fingering patterns suggest that fingers travel through preferential pathways by means of pore size heterogeneities. These heterogeneities may act as zones of high or low permeability. For various correlation lengths the appearance of long dominant fingers can be observed. Advisors/Committee Members: Hassanizadeh, S.M., Joekar-Niasar, V..

Subjects/Keywords: Geowetenschappen; viscous fingering, pore-network model, heterogeneity, correlation length, Delaunay triangulation, spatial correlation, tessellation

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APA (6^th Edition):

Leng, C. C. (2013). The Effect of Spatial Correlation on Viscous Fingering in a Dynamic Pore-Network Model with Delaunay Tessellated Structure. (Masters Thesis). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/279850

Chicago Manual of Style (16^th Edition):

Leng, C C. “The Effect of Spatial Correlation on Viscous Fingering in a Dynamic Pore-Network Model with Delaunay Tessellated Structure.” 2013. Masters Thesis, Universiteit Utrecht. Accessed March 08, 2021. http://dspace.library.uu.nl:8080/handle/1874/279850.

MLA Handbook (7^th Edition):

Leng, C C. “The Effect of Spatial Correlation on Viscous Fingering in a Dynamic Pore-Network Model with Delaunay Tessellated Structure.” 2013. Web. 08 Mar 2021.

Vancouver:

Leng CC. The Effect of Spatial Correlation on Viscous Fingering in a Dynamic Pore-Network Model with Delaunay Tessellated Structure. [Internet] [Masters thesis]. Universiteit Utrecht; 2013. [cited 2021 Mar 08]. Available from: http://dspace.library.uu.nl:8080/handle/1874/279850.

Council of Science Editors:

Leng CC. The Effect of Spatial Correlation on Viscous Fingering in a Dynamic Pore-Network Model with Delaunay Tessellated Structure. [Masters Thesis]. Universiteit Utrecht; 2013. Available from: http://dspace.library.uu.nl:8080/handle/1874/279850

University of Michigan

25. You, Mingdi. Statistical Models for Characterizing Heterogeneous Wake Effects in a Wind Farm.

Degree: PhD, Industrial & Operations Engineering, 2017, University of Michigan

URL: http://hdl.handle.net/2027.42/138788

► Wind energy is becoming one of the most promising renewable sources. With the rapid growth of wind energy, modern utility-scale wind farms consist of a… (more)

▼ Wind energy is becoming one of the most promising renewable sources. With the rapid growth of wind energy, modern utility-scale wind farms consist of a large number of wind turbines. In order to improve the power generation efficiency of wind turbines, an accurate quantification of power generations from multiple turbines is critical in both wind farm design and operational controls. One challenging issue is that the power outputs from turbines are different from a stand-alone turbine because of complex interactions among turbines, known as the wake effects. In general, upstream turbines absorb kinetic energy from wind. Therefore, downstream turbines tend to produce less power than upstream turbines. Moreover, depending on weather conditions, the power deficits of downstream turbines exhibit heterogeneous patterns. In order to address these challenges, this dissertation study initiates two major ideas: (1) to analyze the stochastic nature of generating wind energy, this study avoids the traditional approach which focuses on wind field modeling within a wind farm. Instead, this study proposes new statistical approaches that directly model the relationship between free-flow wind conditions and power generations from multiple turbines; (2) to analyze the physical interactions among wind turbines, this dissertation proposes data-driven approaches in a comprehensive framework. The objective of this research is to provide a new integrative methodology to characterize multi-turbines' heterogeneous performance at a wind farm scale. Specifically, this dissertation develops: 1. a new statistical model for characterizing heterogeneous wake effects under the dominant wind direction; 2. a canonical model-based approach to handle wake effects under different wind directions; and 3. a new method to quantify the improvement of power productions through retrofitting, e.g., the vortex generator VG installation. In a wind farm, interactions among turbines alter the power generation efficiency of turbines. Moreover the power deficits of downstream turbines in a wind farm exhibit heterogeneous patterns, depending on wind conditions. This study first characterizes heterogeneous wake effects under a dominant wind direction. The proposed model decomposes the power outputs into the average pattern commonly exhibited by all turbines and the turbine-to-turbine variability caused by multi-turbine interactions. To capture the interactions among turbines, turbine-specific regression parameters are modeled using a Gaussian Markov random field (GMRF). Second, the power curve of each turbine becomes heterogeneous when changes in wind directions cause some upstream turbines to become downstream turbines. This dissertation proposes an integrative methodology that quantifies the heterogeneous wake effects over a range of wind directions by utilizing the concept of canonical models and similarity functions. The direction-dependent multi-turbine power curves are modeled in a Bayesian hierarchical framework. Lastly, based on the model… Advisors/Committee Members: Byon, Eunshin (committee member), Berrocal, Veronica (committee member), Guikema, Seth David (committee member), Jin, Judy (committee member).

Subjects/Keywords: Wind energy, Wake effects, Spatial modeling, Heterogeneity; Industrial and Operations Engineering; Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

You, M. (2017). Statistical Models for Characterizing Heterogeneous Wake Effects in a Wind Farm. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/138788

Chicago Manual of Style (16^th Edition):

You, Mingdi. “Statistical Models for Characterizing Heterogeneous Wake Effects in a Wind Farm.” 2017. Doctoral Dissertation, University of Michigan. Accessed March 08, 2021. http://hdl.handle.net/2027.42/138788.

MLA Handbook (7^th Edition):

You, Mingdi. “Statistical Models for Characterizing Heterogeneous Wake Effects in a Wind Farm.” 2017. Web. 08 Mar 2021.

Vancouver:

You M. Statistical Models for Characterizing Heterogeneous Wake Effects in a Wind Farm. [Internet] [Doctoral dissertation]. University of Michigan; 2017. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/2027.42/138788.

Council of Science Editors:

You M. Statistical Models for Characterizing Heterogeneous Wake Effects in a Wind Farm. [Doctoral Dissertation]. University of Michigan; 2017. Available from: http://hdl.handle.net/2027.42/138788

University of Georgia

26. Sabin, Joel Sean. Investigating eastern North American tree species richness and diversity using releve data.

Degree: 2014, University of Georgia

URL: http://hdl.handle.net/10724/22499

► Species richness and diversity are products of interacting ecological, evolutionary, historical, and geographic processes. Processes varying at broader scales may influence data collected over finer… (more)

Subjects/Keywords: Braun-Blanquet; RelevŽ; Eastern deciduous forests; Species richness; Species evenness; Topographic heterogeneity; Spatial autocorrelation

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APA (6^th Edition):

Sabin, J. S. (2014). Investigating eastern North American tree species richness and diversity using releve data. (Thesis). University of Georgia. Retrieved from http://hdl.handle.net/10724/22499

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Sabin, Joel Sean. “Investigating eastern North American tree species richness and diversity using releve data.” 2014. Thesis, University of Georgia. Accessed March 08, 2021. http://hdl.handle.net/10724/22499.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Sabin, Joel Sean. “Investigating eastern North American tree species richness and diversity using releve data.” 2014. Web. 08 Mar 2021.

Vancouver:

Sabin JS. Investigating eastern North American tree species richness and diversity using releve data. [Internet] [Thesis]. University of Georgia; 2014. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/10724/22499.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Sabin JS. Investigating eastern North American tree species richness and diversity using releve data. [Thesis]. University of Georgia; 2014. Available from: http://hdl.handle.net/10724/22499

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Universidade Federal de Viçosa

27. Frederico de Siqueira Neves. Efeitos da estrutura do habitat sobre insetos herbívoros associados ao dossel.

Degree: 2005, Universidade Federal de Viçosa

URL: http://www.tede.ufv.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=587

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O dossel de florestas tropicais oferece uma grande diversidade de recursos que são essenciais para a manutenção da biodiversidade. Entretanto, poucos estudos verificaram os efeitos… (more)

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O dossel de florestas tropicais oferece uma grande diversidade de recursos que são essenciais para a manutenção da biodiversidade. Entretanto, poucos estudos verificaram os efeitos da estrutura do dossel sobre comunidades de insetos herbívoros em regiões tropicais. O objetivo deste estudo foi responder por que a diversidade de insetos herbívoros varia no dossel de uma floresta. Para isso foi testada a hipótese de que a abundancia e riqueza de insetos herbívoros são afetadas pela estrutura do dossel em duas escalas espaciais distintas, verificando estes efeitos em duas guildas alimentares: insetos herbívoros sugadores e mastigadores. Foram amostrados 314 insetos herbívoros. A guilda de insetos herbívoros mastigadores foi mais rica e abundante, apresentando 91 morfoespecies e 235 indivíduos. Foi verificado que a estrutura do dossel influencia a abundancia e riqueza de insetos herbívoros em diferentes escalas espaciais, de acordo com a guilda alimentar. Insetos herbívoros sugadores respondem aos efeitos da arquitetura da árvore hospedeira na escala local (arquitetura da árvore), aumentando a abundancia e riqueza de espécies com o aumento do tamanho da árvore hospedeira. Já insetos herbívoros mastigadores aumentam sua abundancia com o tamanho da árvore hospederia, na escala local, e aumentam a sua abundancia e a riqueza de espécies com a densidade foliar do dossel, na escala regiões do dossel. Ambas as guildas não são afetadas pela complexidade das copas das árvores ou pela riqueza de espécies de árvores.

The canopy of tropical forests offers a large diversity of resources that are essential for the maintenance of the biodiversity. There is a lack of studies on the effects of canopy habitat structure upon herbivorous communities, mainly at tropical regions. The aim of this study was to answer why herbivorous insect diversity varies within the forest canopy. We tested the hypothesis that herbivores abundance and species richness are affected by canopy structure, comparing two distinct spatial scales and two different feeding guilds: sap-sucking and chewing herbivores. We collected 314 herbivorous insect individuals. Herbivorous chewers was the richest and most abundant guild, with 91 morphospecies and 235 individuals. Canopy structure influences insect herbivores abundance and species richness in different spatial scales, according to the herbivores guild. Sap-sucking herbivores respond to plant architecture on a local spatial scale (tree architecture), increase their abundance and species richness with tree size. While chewing herbivores increase their abundance with tree size, and increase their abundance and species richness with leaf density within the canopy, on a larger spatial scale. Neither of the herbivorous guilds species richness were affected by tree crown complexity nor tree species richness.

Advisors/Committee Members: Carlos Frankl Sperber, José Henrique Schoereder, Og Francisco Fonseca de Souza, Flavio Antonio Maes dos Santos, Servio Pontes Ribeiro.

Subjects/Keywords: Arquitetura de planta; Ecologia de dossel; Heterogeneidade espacial; ECOLOGIA; Plant architecture; Canopy ecology; Spatial heterogeneity

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Neves, F. d. S. (2005). Efeitos da estrutura do habitat sobre insetos herbívoros associados ao dossel. (Thesis). Universidade Federal de Viçosa. Retrieved from http://www.tede.ufv.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=587

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Neves, Frederico de Siqueira. “Efeitos da estrutura do habitat sobre insetos herbívoros associados ao dossel.” 2005. Thesis, Universidade Federal de Viçosa. Accessed March 08, 2021. http://www.tede.ufv.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=587.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Neves, Frederico de Siqueira. “Efeitos da estrutura do habitat sobre insetos herbívoros associados ao dossel.” 2005. Web. 08 Mar 2021.

Vancouver:

Neves FdS. Efeitos da estrutura do habitat sobre insetos herbívoros associados ao dossel. [Internet] [Thesis]. Universidade Federal de Viçosa; 2005. [cited 2021 Mar 08]. Available from: http://www.tede.ufv.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=587.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Neves FdS. Efeitos da estrutura do habitat sobre insetos herbívoros associados ao dossel. [Thesis]. Universidade Federal de Viçosa; 2005. Available from: http://www.tede.ufv.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=587

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Waikato

28. Simmonds, Bernard Michael. Spatial and temporal trends of phytoplankton and physiochemical variables in a hypertrophic, monomictic lake .

Degree: 2011, University of Waikato

URL: http://hdl.handle.net/10289/6031

► Spatial and temporal variations in the physical, chemical and biological composition of Lake Ōkaro were measured over 16 months. Lake Ōkaro is a small (0.32… (more)

▼ Spatial and temporal variations in the physical, chemical and biological composition of Lake Ōkaro were measured over 16 months. Lake Ōkaro is a small (0.32 km2) hypertrophic, monomictic lake located in the Central Volcanic Zone of the North Island, New Zealand. Vertical profiles of temperature, chlorophyll fluorescence, dissolved oxygen concentration (DO), pH, specific conductance, photosynthetically active radiation (PAR) and nutrient species, including ammonium-nitrogen (NH4-N), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N) and phosphate-phosphorus (PO4-P), were collected at up to nine stations at weekly to monthly frequencies. High-frequency variability was assessed during two separate 24-hour monitoring periods, coinciding with an Anabaena spiroides-dominated surface bloom, and a Ceratium hirundinella-dominated deep chlorophyll maximum. Additional data for wind direction and velocity, incident solar irradiance and rainfall was sourced from a meteorological weather station and a lake monitoring buoy at Rotorua, 20 km north of the lake. Spatial variability was more pronounced during summer. Observed vertical gradients in chlorophyll fluorescence, DO, specific conductance and nutrient species were closely linked to thermal stability of the water column. There were large variations in chlorophyll fluorescence amongst stations in summer, which related to displacement of the metalimnion and associated changes in chlorophyll fluorescence. Winter mixing was characterised by relative homogeneity of the water column. Nutrient concentrations were elevated at all depths whereas high concentrations had previously been confined to lower depth strata (the hypolimnion). Temperature profiles in summer displayed clear vertical gradients with a well-defined metalimnion that increased in depth until winter mixing generated isothermal conditions. Chlorophyll fluorescence profiles were characterised by the formation of a DCM that was recurrent over both summer periods, and was strongly statistically related to the depth of the thermocline for the duration of stratification. Dissolved oxygen, specific conductance and pH were relatively uniform horizontally, though pH was consistently lower at a well-sheltered near-shore station. All variables showed strong variations with depth during the stratified period. Dissolved oxygen was negligible or zero below the thermocline for much of the stratified period while specific conductance was lowest above or at the thermocline. There were also strong vertical gradients in nutrient concentrations in summer, with concentrations below the thermocline often an order of magnitude higher than those above. The representativeness of fluorescence at a central station to a whole-lake scale was assessed using a vertical integrated value and the standard error derived from up to eight other stations. Values at the single station frequently deviated from the mean fluorescence of the wider lake, particularly at the DCM which suggests that extrapolating single-station measurements to a whole lake could… Advisors/Committee Members: Wood, Susanna A (advisor), Hamilton, David P (advisor), Özkundakci, Deniz (advisor).

Subjects/Keywords: Phytoplankton; heterogeneity; variability; monomictic; Rotorua; Okaro; DCM; bloom; deep; chlorophyll; maximum; spatial; temporal; monitoring

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Simmonds, B. M. (2011). Spatial and temporal trends of phytoplankton and physiochemical variables in a hypertrophic, monomictic lake . (Masters Thesis). University of Waikato. Retrieved from http://hdl.handle.net/10289/6031

Chicago Manual of Style (16^th Edition):

Simmonds, Bernard Michael. “Spatial and temporal trends of phytoplankton and physiochemical variables in a hypertrophic, monomictic lake .” 2011. Masters Thesis, University of Waikato. Accessed March 08, 2021. http://hdl.handle.net/10289/6031.

MLA Handbook (7^th Edition):

Simmonds, Bernard Michael. “Spatial and temporal trends of phytoplankton and physiochemical variables in a hypertrophic, monomictic lake .” 2011. Web. 08 Mar 2021.

Vancouver:

Simmonds BM. Spatial and temporal trends of phytoplankton and physiochemical variables in a hypertrophic, monomictic lake . [Internet] [Masters thesis]. University of Waikato; 2011. [cited 2021 Mar 08]. Available from: http://hdl.handle.net/10289/6031.

Council of Science Editors:

Simmonds BM. Spatial and temporal trends of phytoplankton and physiochemical variables in a hypertrophic, monomictic lake . [Masters Thesis]. University of Waikato; 2011. Available from: http://hdl.handle.net/10289/6031

West Virginia University

29. Gao, Danqing. The influence of spatial variance on rock strength and mechanism of failure.

Degree: PhD, Mining Engineering, 2020, West Virginia University

URL: https://doi.org/10.33915/etd.7703 ; https://researchrepository.wvu.edu/etd/7703

► The heterogeneity in the rock formation affects both rock behavior and the strength. The effect of heterogeneity is observed both at the laboratory scale… (more)

▼ The heterogeneity in the rock formation affects both rock behavior and the strength. The effect of heterogeneity is observed both at the laboratory scale and at the rockmass level. The mechanical properties of intact rock vary considerably at laboratory scale and often an average value is used for design purposes. Similarly, the values are arbitrarily scaled when used at rockmass level. In underground coal mines, the effect of variability of properties is often observed with the erratic roof failure events that occur throughout the mine. The approach often was to use the deterministic values from limited site data to estimate the rock strength and ignoring the inherent variability of rockmass properties. However, current numerical models have successfully captured the global behavior showing the effect of in-situ stress, geology, operational parameters, etc. This dissertation proposes a probabilistic approach that assumes that rockmass properties as random variables and examines its effect on underground coal mine. The effect of random properties was examined by comparing the deterministic and completely random models which showed the importance of using randomness factor in rocks. Subsequently a spatially correlated random model investigated the influence of rock heterogeneity on rock strength and failure propagation. A random field database with specific spatial correlation was created for each physico-mechanical property using laboratory data and Extreme Value stochastic model in MATLAB. Two scale-measured parameters defined the correlation length, which controls the spatially correlated random data. Then, to verify the importance of the four parameters, friction, cohesion, and correlation length along the horizontal and vertical axes, one hundred and fifty two random sample data are generated. The stress for each specimen is tracked at different loading steps with different spatial correlation factors. This approach determined the effect of material model parameters affect the internal stress distribution for intact rocks. The models were further validated by predicting the behavior of rocks from controlled triaxial tests. Results from the laboratory tests were matched the predicted behavior from numerical models verifying the proposed stochastic method. The stochastic method was then implemented in the three-dimensional numerical model to investigate a longwall mine operating in Pittsburgh seam. The influence of random field data on entry roof in the longwall mining system was investigated. Based on Extreme Value stochastic model, the realistic random field database added two scale-measured parameters from both horizontal and vertical directions to control the spatial correlation length. This model also considered a number of cutting sequences, for identifying the effect of the spatial variance on the roof behavior. Finally, the outcome of the dissertation was to use probabilistic approach for demonstrating the heterogeneous characteristic of rock and the influence of spatial variance on the… Advisors/Committee Members: Brijes Mishra, Yi Luo.

Subjects/Keywords: Rock; heterogeneity; Extreme Value distribution; spatial variance; correlation; MATLAB; stochastic simulation; Mining Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Gao, D. (2020). The influence of spatial variance on rock strength and mechanism of failure. (Doctoral Dissertation). West Virginia University. Retrieved from https://doi.org/10.33915/etd.7703 ; https://researchrepository.wvu.edu/etd/7703

Chicago Manual of Style (16^th Edition):

Gao, Danqing. “The influence of spatial variance on rock strength and mechanism of failure.” 2020. Doctoral Dissertation, West Virginia University. Accessed March 08, 2021. https://doi.org/10.33915/etd.7703 ; https://researchrepository.wvu.edu/etd/7703.

MLA Handbook (7^th Edition):

Gao, Danqing. “The influence of spatial variance on rock strength and mechanism of failure.” 2020. Web. 08 Mar 2021.

Vancouver:

Gao D. The influence of spatial variance on rock strength and mechanism of failure. [Internet] [Doctoral dissertation]. West Virginia University; 2020. [cited 2021 Mar 08]. Available from: https://doi.org/10.33915/etd.7703 ; https://researchrepository.wvu.edu/etd/7703.

Council of Science Editors:

Gao D. The influence of spatial variance on rock strength and mechanism of failure. [Doctoral Dissertation]. West Virginia University; 2020. Available from: https://doi.org/10.33915/etd.7703 ; https://researchrepository.wvu.edu/etd/7703

University of Iowa

30. Dermisis, Dimitrios Charalampos. Developing an improved, shock-capturing watershed model for simulating spatially variable runoff and soil erosion processes at the hillslope scale.

Degree: PhD, Civil and Environmental Engineering, 2012, University of Iowa

URL: https://ir.uiowa.edu/etd/5930

► The overarching objective of this study was the development, validation and testing of an improved watershed modeling framework that accounts for the effects of… (more)

▼ The overarching objective of this study was the development, validation and testing of an improved watershed modeling framework that accounts for the effects of spatial heterogeneity on overland flow and erosion processes and it is computationally sound for shallow, overland flows with shock waves. Most of the existing soil erosion models determine fluxes of water and sediment with the assumption of a homogeneous hill. In these models the physical and biogeochemical properties of the heterogeneous hill are spatially averaged, without considering roughness and longitudinal curvature effects as well as differences in the land use/land cover -LU/LC- and soil properties along the hill. This issue was addressed by improving the Water Erosion Prediction Project (WEPP-Original version 2010.1) soil erosion model at the hillslope scale to account for the physics in terms of spatial heterogeneity in flow using a well-established shock-capturing numerical scheme. The improved WEPP model, referred to as "WEPP-Improved" model was (i) validated via detailed field experiments within an experimental plot and (ii) tested via generic simulations at the hillslope scale covering a variety of scenarios in terms of topography, LU/LC and soil type. Results showed that the WEPP-Improved model could effectively simulate the unsteadiness of the flow as well as the required time (lag) for the flow rate to reach equilibrium conditions. However, the model provided only a steady-state sediment transport rate and could capture only the equilibrium conditions. Further, the WEPP-Improved model reflected the effects of curvature, LU/LC and soil type on flow, as the model did not treat the hillslope as a homogeneous unit. Based on the generic simulations, landscape variability resulted to differences in the predicted peak runoff rate, Qpeak, between the WEPP-Improved vs. WEPP-Original models ranging ~ 3 - 62 % (avg. 19 %) due to curvature effects only, ~ 17 - 170 % (avg. ~ 66 %) due to added effects of LU/LC variability and ~ 5 % - 200 % (avg. ~ 52 %) due to added effects of soil type variability. The highest reported differences on the predicted Qpeak between the two models were attributed to the formation of the shock waves; these differences were dominant for the low in magnitude storm event and attenuated for the high event. It is believed that if the physical processes are represented accurately at the hillslope scale using the suggested modeling framework, then by utilizing an appropriate routing scheme of the flow and sediment within the stream network, it will be possible to scale-up the flow/sediment routing from the hillslope to the watershed scale without losing the degree of heterogeneity encapsulated from different hillslopes within the drainage network. Advisors/Committee Members: Papanicolaou, Athanasios (supervisor).

Subjects/Keywords: erosion; overland flow; roughness; spatial heterogeneity; topography; WEPP; Civil and Environmental Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Dermisis, D. C. (2012). Developing an improved, shock-capturing watershed model for simulating spatially variable runoff and soil erosion processes at the hillslope scale. (Doctoral Dissertation). University of Iowa. Retrieved from https://ir.uiowa.edu/etd/5930

Chicago Manual of Style (16^th Edition):

Dermisis, Dimitrios Charalampos. “Developing an improved, shock-capturing watershed model for simulating spatially variable runoff and soil erosion processes at the hillslope scale.” 2012. Doctoral Dissertation, University of Iowa. Accessed March 08, 2021. https://ir.uiowa.edu/etd/5930.

MLA Handbook (7^th Edition):

Dermisis, Dimitrios Charalampos. “Developing an improved, shock-capturing watershed model for simulating spatially variable runoff and soil erosion processes at the hillslope scale.” 2012. Web. 08 Mar 2021.

Vancouver:

Dermisis DC. Developing an improved, shock-capturing watershed model for simulating spatially variable runoff and soil erosion processes at the hillslope scale. [Internet] [Doctoral dissertation]. University of Iowa; 2012. [cited 2021 Mar 08]. Available from: https://ir.uiowa.edu/etd/5930.

Council of Science Editors:

Dermisis DC. Developing an improved, shock-capturing watershed model for simulating spatially variable runoff and soil erosion processes at the hillslope scale. [Doctoral Dissertation]. University of Iowa; 2012. Available from: https://ir.uiowa.edu/etd/5930

Open Access Theses and Dissertations