11 resultados para Numerical integration methods
em Digital Commons at Florida International University
Resumo:
The purpose of this dissertation was to examine the effect of academic integration, defined in terms of instructor/student contact, on the persistence of under-prepared college students and the achievement of those who persist. The overall design of this study compared instructor-initiated contact with conventional contact. The dependent variables were persistence, achievement, motivation and anxiety. Information was collected by administering the College-Level Mathematics Test (CLM), the Perceived Affective Contact Questionnaire (PAC), the expectancy and anxiety components of the Motivated Strategies for Learning Questionnaire (MSLQ), a departmental final examination, and by accessing university records. The sample consisted of 130 college algebra students at a large, public university with a Hispanic majority. The main analyses consisted of a 2 x 2 x 2 ANOVA (treatment by ethnicity by gender) to test for differences in achievement, t-tests to compare motivation, anxiety and perceived affective contact scores for the two groups, Chi-square tests to assess differences in persistence, and Pearson Product-Moment Correlation to determine the relationship between pretest scores and achievement variables. Results indicated that neither instructor-initiated contact, gender nor ethnicity is related to persistence, motivation or anxiety. A significant disordinal interaction of treatment and ethnicity was observed, with Hispanic experimental students scoring significantly higher on a test of algebra achievement than Hispanic control students. ^ Academic integration, defined in terms of instructor/student contact, has a positive influence on the achievement of Hispanic students. This may imply their positive responsiveness to the relational aspect of contact due to traditional cultural values of interdependence, acquiescence to authority and physical closeness. Such interactive feedback is a means by which students with these values are recognized as members of the university academic community, prompting increased academic effort. Training in contact initiation to promote academic integration is implied, by the results of this study, for instructors dealing with first year students, especially instructors at institutions accommodating instructional methods to the needs of diverse groups. ^
Resumo:
The purpose of this investigation was to develop new techniques to generate segmental assessments of body composition based on Segmental Bioelectrical Impedance Analysis (SBIA). An equally important consideration was the design, simulation, development, and the software and hardware integration of the SBIA system. This integration was carried out with a Very Large Scale Integration (VLSI) Field Programmable Gate Array (FPGA) microcontroller that analyzed the measurements obtained from segments of the body, and provided full body and segmental Fat Free Mass (FFM) and Fat Mass (FM) percentages. Also, the issues related to the estimate of the body's composition in persons with spinal cord injury (SCI) were addressed and investigated. This investigation demonstrated that the SBIA methodology provided accurate segmental body composition measurements. Disabled individuals are expected to benefit from these SBIA evaluations, as they are non-invasive methods, suitable for paralyzed individuals. The SBIA VLSI system may replace bulky, non flexible electronic modules attached to human bodies. ^
Resumo:
In topographically flat wetlands, where shallow water table and conductive soil may develop as a result of wet and dry seasons, the connection between surface water and groundwater is not only present, but perhaps the key factor dominating the magnitude and direction of water flux. Due to their complex characteristics, modeling waterflow through wetlands using more realistic process formulations (integrated surface-ground water and vegetative resistance) is an actual necessity. This dissertation focused on developing an integrated surface – subsurface hydrologic simulation numerical model by programming and testing the coupling of the USGS MODFLOW-2005 Groundwater Flow Process (GWF) package (USGS, 2005) with the 2D surface water routing model: FLO-2D (O’Brien et al., 1993). The coupling included the necessary procedures to numerically integrate and verify both models as a single computational software system that will heretofore be referred to as WHIMFLO-2D (Wetlands Hydrology Integrated Model). An improved physical formulation of flow resistance through vegetation in shallow waters based on the concept of drag force was also implemented for the simulations of floodplains, while the use of the classical methods (e.g., Manning, Chezy, Darcy-Weisbach) to calculate flow resistance has been maintained for the canals and deeper waters. A preliminary demonstration exercise WHIMFLO-2D in an existing field site was developed for the Loxahatchee Impoundment Landscape Assessment (LILA), an 80 acre area, located at the Arthur R. Marshall Loxahatchee National Wild Life Refuge in Boynton Beach, Florida. After applying a number of simplifying assumptions, results have illustrated the ability of the model to simulate the hydrology of a wetland. In this illustrative case, a comparison between measured and simulated stages level showed an average error of 0.31% with a maximum error of 2.8%. Comparison of measured and simulated groundwater head levels showed an average error of 0.18% with a maximum of 2.9%. The coupling of FLO-2D model with MODFLOW-2005 model and the incorporation of the dynamic effect of flow resistance due to vegetation performed in the new modeling tool WHIMFLO-2D is an important contribution to the field of numerical modeling of hydrologic flow in wetlands.
Resumo:
The study explored when, under what conditions, and to what extent did European integration, particularly the European Union’s requirement for democratic conditionality, contribute to democratic consolidation in Spain, Poland, and Turkey? On the basis of a four-part definition, the dissertation examined the democratizing impact of European integration process on each of the following four components of consolidation: (i) holding of fair, free and competitive elections, (ii) protection of fundamental rights, including human and minority rights, (iii) high prospects of regime survival and civilian control of the military, and (iv) legitimacy, elite consensus, and stateness. To assess the relative significance of EU’s democratizing leverage, the thesis also examined domestic and non-EU international dynamics of democratic consolidation in the three countries. By employing two qualitative methods (case study and process-tracing), the study focused on three specific time frames: 1977–1986 for Spain, 1994–2004 for Poland, and 1999–present for Turkey. In addition to official documents, newspapers, and secondary sources, face-to-face interviews made with politicians, academics, experts, bureaucrats, and journalists in the three countries were utilized. The thesis generated several conclusions. First of all, the EU’s democratizing impact is not uniform across different components of democratic consolidation. Moreover, the EU’s democratizing leverage in Spain, Poland, and Turkey involved variations over time for three major reasons: (i) the changing nature of EU’s democratic conditionality over time (ii) varying levels of the EU’s credible commitment to the candidate country’s prospect for membership, and (iii) domestic dynamics in the candidate countries. Furthermore, the European integration process favors democratic consolidation but its magnitude is shaped by the candidate country’s prospect for EU membership and domestic factors in the candidate country. Finally, the study involves a major policy implication for the European Union: unless the EU provides a clear prospect for membership, its democratizing leverage will be limited in the candidate countries.
Resumo:
This mixed-methods study examined effects of a staff development model on instructional practices and dispositions of P-12 teachers. The model design was guided by participants’ varying developmental levels and their values and beliefs about teaching and learning. The study adds to our understanding of the need for teacher-centered professional development.
Resumo:
The main goal of this dissertation was to study two- and three-nucleon Short Range Correlations (SRCs) in high energy three-body breakup of 3He nucleus in 3He(e, e'NN) N reaction. SRCs are characterized by quantum fluctuations in nuclei during which constituent nucleons partially overlap with each other. ^ A theoretical framework is developed within the Generalized Eikonal Approximation (GEA) which upgrades existing medium-energy methods that are inapplicable for high momentum and energy transfer reactions. High momentum and energy transfer is required to provide sufficient resolution for probing SRCs. GEA is a covariant theory which is formulated through the effective Feynman diagrammatic rules. It allows self-consistent calculation of single and double re-scatterings amplitudes which are present in three-body breakup processes. The calculations were carried out in detail and the analytical result for the differential cross section of 3He(e, e'NN)N reaction was derived in a form applicable for programming and numerical calculations. The corresponding computer code has been developed and the results of computation were compared to the published experimental data, showing satisfactory agreement for a wide range of values of missing momenta. ^ In addition to the high energy approximation this study exploited the exclusive nature of the process under investigation to gain more information about the SRCs. The description of the exclusive 3He( e, e'NN)N reaction has been done using the formalism of the nuclear decay function, which is a practically unexplored quantity and is related to the conventional spectral function through the integration of the phase space of the recoil nucleons. Detailed investigation showed that the decay function clearly exhibits the main features of two- and three-nucleon correlations. Four highly practical types of SRCs in 3He nucleus were discussed in great detail for different orders of the final state re-interactions using the decay function as an unique identifying tool. ^ The overall conclusion in this dissertation suggests that the investigation of the decay function opens up a completely new venue in studies of short range nuclear properties. ^
Resumo:
The Florida Everglades has a long history of anthropogenic changes which have impacted the quantity and quality of water entering the system. Since the construction of Tamiami Trail in the 1920's, overland flow to the Florida Everglades has decreased significantly, impacting ecosystems from the wetlands to the estuary. The MIKE Marsh Model of Everglades National Park (M3ENP) is a numerical model, which simulates Everglades National Park (ENP) hydrology using MIKE SHE/MIKE 11software. This model has been developed to determine the parameters that effect Everglades hydrology and understand the impact of specific flow changes on the hydrology of the system. ^ As part of the effort to return flows to the historical levels, several changes to the existing water management infrastructure have been implemented or are in the design phase. Bridge construction scenarios were programed into the M3ENP model to review the effect of these structural changes and evaluate the potential impacts on water levels and hydroperiods in the receiving Northeast Shark Slough ecosystem. These scenarios have shown critical water level increases in an area which has been in decline due to low water levels. Results from this work may help guide future decisions for restoration designs. ^ Excess phosphorus entering Everglades National Park in South Florida may promote the growth of more phosphorus-opportunistic species and alter the food chain from the bottom up. Two phosphorus transport methods were developed into the M3ENP hydrodynamic model to determine the factors affecting phosphorus transport and the impact of bridge construction on water quality. Results showed that while phosphorus concentrations in surface waters decreased overall, some areas within ENP interior may experience an increase in phosphorus loading which the addition of bridges to Tamiami Trail. Finally, phosphorus data and modeled water level data was used to evaluate the spectral response of Everglades vegetation to increasing phosphorus availability using Landsat imagery.^
Resumo:
This dissertation focused on developing an integrated surface – subsurface hydrologic simulation numerical model by programming and testing the coupling of the USGS MODFLOW-2005 Groundwater Flow Process (GWF) package (USGS, 2005) with the 2D surface water routing model: FLO-2D (O’Brien et al., 1993). The coupling included the necessary procedures to numerically integrate and verify both models as a single computational software system that will heretofore be referred to as WHIMFLO-2D (Wetlands Hydrology Integrated Model). An improved physical formulation of flow resistance through vegetation in shallow waters based on the concept of drag force was also implemented for the simulations of floodplains, while the use of the classical methods (e.g., Manning, Chezy, Darcy-Weisbach) to calculate flow resistance has been maintained for the canals and deeper waters. A preliminary demonstration exercise WHIMFLO-2D in an existing field site was developed for the Loxahatchee Impoundment Landscape Assessment (LILA), an 80 acre area, located at the Arthur R. Marshall Loxahatchee National Wild Life Refuge in Boynton Beach, Florida. After applying a number of simplifying assumptions, results have illustrated the ability of the model to simulate the hydrology of a wetland. In this illustrative case, a comparison between measured and simulated stages level showed an average error of 0.31% with a maximum error of 2.8%. Comparison of measured and simulated groundwater head levels showed an average error of 0.18% with a maximum of 2.9%.
Resumo:
The main goal of this dissertation was to study two- and three-nucleon Short Range Correlations (SRCs) in high energy three-body breakup of 3He nucleus in 3He(e, e'NN)N reaction. SRCs are characterized by quantum fluctuations in nuclei during which constituent nucleons partially overlap with each other. A theoretical framework is developed within the Generalized Eikonal Approximation (GEA) which upgrades existing medium-energy methods that are inapplicable for high momentum and energy transfer reactions. High momentum and energy transfer is required to provide sufficient resolution for probing SRCs. GEA is a covariant theory which is formulated through the effective Feynman diagrammatic rules. It allows self-consistent calculation of single and double re-scatterings amplitudes which are present in three-body breakup processes. The calculations were carried out in detail and the analytical result for the differential cross section of 3He(e, e'NN)Nreaction was derived in a form applicable for programming and numerical calculations. The corresponding computer code has been developed and the results of computation were compared to the published experimental data, showing satisfactory agreement for a wide range of values of missing momenta. In addition to the high energy approximation this study exploited the exclusive nature of the process under investigation to gain more information about the SRCs. The description of the exclusive 3He(e, e'NN)N reaction has been done using the formalism of the nuclear decay function, which is a practically unexplored quantity and is related to the conventional spectral function through the integration of the phase space of the recoil nucleons. Detailed investigation showed that the decay function clearly exhibits the main features of two- and three-nucleon correlations. Four highly practical types of SRCs in 3He nucleus were discussed in great detail for different orders of the final state re-interactions using the decay function as an unique identifying tool. The overall conclusion in this dissertation suggests that the investigation of the decay function opens up a completely new venue in studies of short range nuclear properties.
Resumo:
The purpose of this dissertation was to examine the effect of academic integration, defined in terms of instructor/student contact, on the persistence of under-prepared college students and the achievement of those who persist. The overall design of this study compared instructor-initiated contact with conventional contact. The dependent variables were persistence, achievement, motivation and anxiety. Information was collected by administering the College-Level Mathematics Test (CLM), the Perceived Affective Contact Questionnaire (PAC), the expectancy and anxiety components of the Motivated Strategies for Learning Questionnaire (MSLQ), a departmental final examination, and by accessing university records. The sample consisted of 130 college algebra students at a large, public university with a Hispanic majority. The main analyses consisted of a 2x2x2 ANOVA (treatment by ethnicity by gender) to test for differences in achievement, t-tests to compare motivation, anxiety and perceived affective contact scores for the two groups, Chi-square tests to assess differences in persistence, and Pearson Product-Moment Correlation to determine the relationship between pretest scores and achievement variables. Results indicated that neither instructor-initiated contact, gender nor ethnicity is related to persistence, motivation or anxiety. A significant disordinal interaction of treatment and ethnicity was observed, with Hispanic experimental students scoring significantly higher on a test of algebra achievement than Hispanic control students. Academic integration, defined in terms of instructor/student contact, has a positive influence on the achievement of Hispanic students. This may imply their positive responsiveness to the relational aspect of contact due to traditional cultural values of interdependence, acquiescence to authority and physical closeness. Such interactive feedback is a means by which students with these values are recognized as members of the university academic community, prompting increased academic effort. Training in contact initiation to promote academic integration is implied, by the results of this study, for instructors dealing with first year students, especially instructors at institutions accommodating instructional methods to the needs of diverse groups.
Resumo:
The Florida Everglades has a long history of anthropogenic changes which have impacted the quantity and quality of water entering the system. Since the construction of Tamiami Trail in the 1920's, overland flow to the Florida Everglades has decreased significantly, impacting ecosystems from the wetlands to the estuary. The MIKE Marsh Model of Everglades National Park (M3ENP) is a numerical model, which simulates Everglades National Park (ENP) hydrology using MIKE SHE/MIKE 11software. This model has been developed to determine the parameters that effect Everglades hydrology and understand the impact of specific flow changes on the hydrology of the system. As part of the effort to return flows to the historical levels, several changes to the existing water management infrastructure have been implemented or are in the design phase. Bridge construction scenarios were programed into the M3ENP model to review the effect of these structural changes and evaluate the potential impacts on water levels and hydroperiods in the receiving Northeast Shark Slough ecosystem. These scenarios have shown critical water level increases in an area which has been in decline due to low water levels. Results from this work may help guide future decisions for restoration designs. Excess phosphorus entering Everglades National Park in South Florida may promote the growth of more phosphorus-opportunistic species and alter the food chain from the bottom up. Two phosphorus transport methods were developed into the M3ENP hydrodynamic model to determine the factors affecting phosphorus transport and the impact of bridge construction on water quality. Results showed that while phosphorus concentrations in surface waters decreased overall, some areas within ENP interior may experience an increase in phosphorus loading which the addition of bridges to Tamiami Trail. Finally, phosphorus data and modeled water level data was used to evaluate the spectral response of Everglades vegetation to increasing phosphorus availability using Landsat imagery.