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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effect of training structures on the establishment of equivalence classes in college students and individuals with intellectual disabilities

Garcia, Yors Alexander 01 May 2011 (has links)
The present studies evaluated the effect of training structures on the development of equivalence classes in college students and individuals with intellectual disabilities. Experiment 1 evaluated the effects of two types of training structures, One-To-Many (OTM) (AB, AC, AD), and Many-To-One (MTO) (BA, CA, DA), on the establishment of equivalence classes in college students. A between group comparison was used in Experiment 1. Forty-two participants were randomly assigned to two different groups. Twenty-one were assigned to the OTM group and twenty-one to the MTO group. Participants in both groups were taught 3 four-member stimulus classes. Participants in both groups were exposed to conditional discrimination training, mixed training, symmetry and equivalence test. Response accuracy and response latency were measured in both groups. The results showed that the MTO training structure was slightly more effective in establishing equivalence classes in college students. In the Experiment 2, six young adults with intellectual disabilities were taught mathematical relations using the MTO training structure which was the most effective training structure in Experiment 1. All participants were taught three 3-member stimulus equivalence classes using the MTO training structure. The experimental sequence consisted of a generalization probe and pretest followed by conditional discrimination training, symmetry test, equivalence test, and posttest. Upon the completion of the training and testing phases a generalization probe was evaluated. Five participants demonstrated equivalence relations. The results show that the MTO training was superior to the OTM in the Experiment 1. Response latencies were faster in the MTO group during the training phases and slower in the testing conditions. Experiment 2 showed that only five participants demonstrated equivalence relations and transferred untaught relations to new setting. Results and implications are discussed in light of the research on equivalence and training structures in both adults and individual with intellectual disabilities.
2

Using HAZUS-MH flood model as a floodplain management tool: Evaluation of river engineering effects on flood losses for the Middle Mississippi River

Carlson, Megan L. 01 December 2010 (has links)
By combining FEMA's HAZUS-MH (Hazards U.S. Multi-Hazard) flood-loss estimation software and the HEC-RAS hydraulic modeling package, this study was able to quantify potential beneficial and adverse impacts of flood-control and navigational structures along the Middle Mississippi River (MMR; between Mississippi-Missouri River confluence and Thebes, IL). The goal of this investigation was to assess changes in water-surface elevations and associated flood losses to: 1) quantify the potential exposure of flooding under different flood-control configurations along the Middle Mississippi River (MMR), and 2) assess the relative contributions of various engineered structures and flood-loss strategies to potential flood losses. Assessment of the impact of engineering structures was accomplished by modeling five scenarios for the 100- and 500- year floods: 1) current MMR levee configuration (levee protecting for ≤50-year flood); 2) removal of all flood-control structures on the MMR; 3) increasing the height of levees and floodwalls in metropolitan St. Louis to protect urban areas to the 500-year flood level while simultaneously removing all agricultural levees downstream; 4A) a less engineered MMR channel and floodplain with fewer flood control and navigation structures, simulating conditions from 65 years ago (1942-1947) with 1940's levees; and 4B) a less engineered MMR channel and floodplain with fewer flood control and navigation structures, simulating conditions from 65 years ago (1942-1947) with current levee configuration. Comparison of scenarios 2 and 3 relative to scenario 1 allows for quantitative assessment of the flood-control structures on stages and flood losses. Results from scenario 2 revealed that removing all levees along the MMR reduces the average stages from 2.2 m (100-year) to 2.5 m (500-year, but also increased economic and social impacts relative to scenario 1. Scenario 3 revealed that removing agricultural levees downstream of St. Louis on the MMR decreased stages by 1.4 m (100- and 500-year); however, flood losses for the 100-year flood were increased. Flood losses for the 500-year flood were decreased relative to scenario 1. These results suggest that agricultural levees along the MMR protect against medium size floods (50- or 100-year flood) but cause more damage than they prevent during large floods such as the 500-year flood. Comparison of scenarios 4A and 4B relative to scenario 1 allows for a quantitative assessment of river engineering structures and modern buildings constructed over the last 65 years. In scenarios 4A and 4B, a less engineered river decreased stages by 1.2 m (for the 100-year flood) relative to scenario 1. In scenario 4A, the 1940's levees expose modern buildings in the floodplain to flooding, causing economic building losses to increase; however, in scenario 4B, current levee configuration protects modern buildings in the floodplain from flooding causing, economic building losses to decrease. If the current flood-control structures were not built, it is likely that the land in the floodplain for scenarios 4A and 4B would not be developed and the land used would be more flood-tolerant. Sensitivity analyses were run to assess the impact of using the default HAZUS-MH national-level data; this was done by comparing results produced by using aggregate analysis (coarse data) versus results using UDF analysis (detailed data). The aggregate analysis estimated 51% fewer buildings damaged than the UDF analysis. Conversely, the aggregate analysis increased the economic building losses by 51% relative to the UDF analysis. Although collecting local data for a study is not always feasible, the large differences documented here need to be considered when discussing HAZUS-MH results. Overall, this project shows implications for historic and future flood-control and navigational structure projects on the MMR and other rivers. It also emphasizes the importance of studying the impact future engineering structures will have on water-surface elevations and flood losses before implementing them.
3

A within-subject comparison of stimulus equivalence training.

Rawls, Medea 08 1900 (has links)
Training structures have been defined as the order and arrangement of baseline conditional discriminations within stimulus equivalence training. The three training structures most often used are, linear (trains A:B and B:C discrimination), many-to-one (trains B:A and C:A discriminations) , and one-to-many (trains A:B and A:C discriminations). Each training structure trains a different set of simultaneous and successive discriminations that are then needed in the test for derived relations (symmetry, reflexivity, transitivity, and symmetrical transitivity). The present experiment seeks to extend the research on stimulus equivalence training structures by using a within-subject design and adult human subjects. Three sets of 9 arbitrary stimuli were trained concurrently each with a different training structure. From the beginning, training and testing trials were intermixed. The likelihood of producing stimulus equivalence formation was equal across structures.
4

ASSESSING THE ROLE OF RIVER TRAINING STRUCTURES – CHEVRON AND DIKE IN THE CREATION AND DIVERSIFICATION OF PHYSICAL AQUATIC HABITATS IN THE MIDDLE MISSISSIPPI RIVER

Karki, Nimisha 01 September 2020 (has links)
The Mississippi River is one of the most intensively managed and altered river systems in the world. The alterations to the Mississippi have been largely made to meet navigation demands and mitigate floods. River training has been undertaken using rock structures, commonly referred to as river training structures (RTS), to modify the shape of the river to maintain the Congressional mandated navigation channel dimensions. In addition to maintaining the navigation channel, newer RTS such as chevrons, have been claimed to be designed as an improvement to the previously existing dikes. They are considered to be tools of improving riverine habitat by increasing physical habitat heterogeneity within the highly engineered and consequently uniform river channel. Thus, to evaluate the differences in physical habitat heterogeneity created by the two RTS; a dike and a chevron, this study models and compares the physical aquatic habitats created along the Middle Mississippi River near Grand Tower, Illinois. The hydraulic modelling software HEC-RAS has been used to develop a two-dimensional model of the study area containing the RTS using detailed 2 m- resolution topobathy digital elevation model (DEM), U.S Geologic Survey’s National Land Cover Database (NLCD), an existing one-dimensional model of the Mississippi and hydrologic data from several hydrologic monitoring stations for the years 2008-2016. Depth and velocity grids were extracted from the HEC-RAS model for three different discharge conditions; 0.5 mean annual flow (MAF) with 40% exceedance probability, MAF with 80% exceedance probability and 1.5 MAF with 15% exceedance probability were used to develop and categorize physical habitat distribution maps of the study area using ArcGIS. The modeled physical aquatic habitat patches were assessed at three buffer distances of 30 m, 90 m, and 150 m from the RTS. The area Simpson diversity and Jaccard similarity indices were calculated for the different discharge conditions and associated habitat mosaics. The distribution of physical habitat modeling revealed a variation in the pattern of habitat patches between the dike and chevron. For the chevron dike evaluated in this study, very-slow deep habitat patches are created in the inner portion of the chevron and slow deep patches around the exterior of the structure which extend both up and downstream of the structure. The dike created slow-deep habitat patches along the structure, very-slow deep patches on the riverbank edge and fast- deep patches on the river side edge. Evaluation of physical habitat patch diversity in relation to the distance from the RTS revealed the highest diversity index values were found within the first 30 m buffer and generally decrease with distance away from the structure. Comparison of the Jaccard index values in vicinity of the two evaluated RTS suggest the habitat patch diversity are similar for both structures at 0.5 MAF and 1.5 MAF flow conditions (index value ranging between 0.60-0.87). However, for the MAF flow conditions the Jaccard index suggests there is more physical habitat patch diversity in the vicinity of the chevron relative to the dike. The modeling results suggest both physical habitat patch richness and diversity declines with an increase in discharge. The decline in physical habitat patch richness and diversity with discharge conditions were greater for the dike relative to the chevron, thus while the chevron retains more types of habitat patches with increase in discharge the diversity indices are still higher for the dike. The modeling also suggests both RTS have created and maintain shallow water habitat (SHW) and overwintering habitat patches (OWH) for the flow conditions evaluated in this study. These habitat patches are utilized by fish species at various life stages. Larger area of OWH habitats; 30% of total area by dikes and 35% of total area by chevrons are created in comparison to SWH; 10% by dike and 7% by chevron. The modeling results show that both the dike and chevron evaluated in this study are associated with and likely maintain ecologically relevant habitats and substantially contribute to physical habitat diversity. If the physical characteristics of the RTS investigated here are similar to other dikes and chevrons along the Mississippi River, the results of this study supports the secondary management objective for these structures, increase in physical aquatic habitat patch diversity, is likely being achieved.

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