• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 389
  • 75
  • 49
  • 37
  • 34
  • 29
  • 19
  • 12
  • 8
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • Tagged with
  • 894
  • 137
  • 135
  • 123
  • 78
  • 75
  • 67
  • 64
  • 63
  • 59
  • 58
  • 58
  • 55
  • 54
  • 54
  • 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.
21

Section 404 permitting in coastal Texas from 1996 - 2003: patterns and effects on streamflow

Highfield, Wesley E. 15 May 2009 (has links)
This study explores the spatial-temporal patterns of Section 404 permitting program under the Clean Water Act and examines its impact on mean and peak annual streamflow. The study area consists of 47 sub-basins that are delineated based on USGS streamflow gauges. These sub-basins span from the southern portion of coastal Texas to the easternmost portion of coastal Texas. Descriptive, spatial and spatial-temporal statistical methods are used to explore patterns in Section 404 permitting between 1996 and 2003. The effects of Section 404 permit types on mean and peak annual streamflow over the same 8 year period are also statistically modeled with a host of other relevant control variables. Exploratory analyses of Section 404 permits demonstrated characteristics that were indicative of suburban and, to a larger extent, exurban development. Explanatory analyses of the effects of Section 404 permitting on mean and peak streamflow showed that Section 404 permits increase both measures. These increases were minimal on a per-permit basis but have the ability to accumulate over time and result in much larger increases. Section 404 permits also displayed an ordered effect based on the permit type. Permit types that represent larger impacts had larger effects. The effects of permits of streamflow followed a descending pattern of Individual permits, Letters of Permission, Nationwide permits, and General permits. This “type of permit impact” supports the use of this measure as an indicator of wetland impact and loss and corroborates previous studies that have incorporated this measure.
22

Quantifying the Uncertainty in Estimates of World Conventional Oil Resources

Tien, Chih-Ming 2009 December 1900 (has links)
Since Hubbert proposed the "peak oil" concept to forecast ultimate recovery of crude oil for the U.S. and the world, there have been countless debates over the timing of peak world conventional oil production rate and ultimate recovery. From review of the literature, forecasts were grouped into those that are like Hubbert's with an imminent peak, and those that do not predict an imminent peak. Both groups have bases for their positions. Viewpoints from the two groups are polarized and the rhetoric is pointed and sometimes personal. A big reason for the large divide between the two groups is the failure of both to acknowledge the significant uncertainty in their estimates. Although some authors attempt to quantify uncertainty, most use deterministic methods and present single values, with no ranges. This research proposes that those that do attempt to quantify uncertainty underestimate it significantly. The objective of this thesis is to rigorously quantify the uncertainty in estimates of ultimate world conventional oil production and time to peak rate. Two different methodologies are used. The first is a regression technique based on historical production data using Hubbert's model and the other methodology uses mathematical models. However, I conduct the analysis probabilistically, considering errors in both the data and the model, which results in likelihood probability distributions for world conventional oil production and time to peak rate. In the second method, I use a multiple-experts analysis to combine estimates from the multitude of papers presented in the literature, yielding an overall distribution of estimated world conventional oil production. Giving due consideration to uncertainty, Hubbert-type mathematical modeling results in large uncertainty ranges that encompass both groups of forecasts (imminent peak and no imminent peak). These ranges are consistent with those from the multiple-experts analysis. In short, the industry does not have enough information at this time to say with any reliability what the ultimate world conventional oil production will be. It could peak soon, somewhere in the distant future, or somewhere in between. It would be wise to consider all of these possible outcomes in planning and making decisions regarding capital investment and formulation of energy policy.
23

Cost-Benefit Assessments of Distributed Power Generation

Yu, Sen-Yen 10 July 2003 (has links)
Abstract The most common application of Distributed Generation (DG) is for reliability reasons. After experiencing an interruption, backup generators can be started to supply electricity to critical loads. The next most common application for DG is peak load shaving. During time periods of high energy demand or high energy prices, on-site generators are started up and used to serve part of the on-site loads. So DG can increase reliability of power supply, reduce loss of interruption and solve the problem of peak loads. Due to the high costs, only a few were installed. In order to investigate their economic values, in this thesis, several economic assessment methods are used to evaluate the cost-benefit of DG. Test results have revealed that, unless it is for environment protection reasons, the investment of DG is of little value if the fuel cost is high, and the electricity and the customer interruption costs are low. Keyword : Distributed Generation¡Mpeak load shaving.
24

Sequence Stratigraphy and Detrital Zircon Geochronology of the Swan Peak Quartzite, Southeastern Idaho

Wulf, Tracy David 2011 December 1900 (has links)
The supermature Middle-Late Ordovician Swan Peak quartz arenite was deposited on the western Laurentia passive margin and is very fine to fine grained, well-rounded, well-sorted, and silica-cemented. Laurentia was positioned over the equator during the Middle-Late Ordovician, suggesting that basement rock along the Transcontinental Arch was intensely eroded in a humid climate to produce this and other coeval quartz arenites. To determine provenance for the Swan Peak Quartzite, zircon grains were analyzed using LA-ICP-MS and the results were constrained within a sequence stratigraphic framework. Depositional environments of the Swan Peak Quartzite record an offshore-to-onshore transition with five facies (A-E). Facies A only occurs at the base of the Bear Lake section and may record an incised valley or localized embayment. It is the deepest water facies in the succession containing shale and quartz arenite interbeds. Facies B through E are interpreted as lower, middle, upper shoreface/foreshore depositional environments, respectively, based on primary sedimentary structures and bioturbation. Detrital zircon age spectra of the Swan Peak Quartzite have four distinct populations: the two main populations are at 1.8 - 2.0 Ga (Paleoproterozoic) and between 2.5 - 3.0 Ga (Archean), with a smaller, but persistent, population at 2.0 - 2.1 Ga, and a very minor 0.8 - 1.2 Ga (Mesoproterozoic) population occurring mainly in the tops of the measured sections. The base of each section has a larger Archean peak whereas the top of each section is predominantly Paleoproterozoic grains. Zircon data have overlap and similarity values ranging between 0.531 - 0.771 and 0.506 - 0.881, respectively, which indicates zircon age spectra of the Swan Peak Quartzite is similar to other Cordilleran Ordovician quartzites and that recycling of heterogeneous underlying sedimentary rocks was minimal. The Wyoming Craton (2.5 - 2.8 Ga) and the Trans-Hudson Orogen (1.8 - 2.0 Ga) provinces near the paleoequator likely provided the majority of zircons in the Swan Peak Quartzite. The source for the 2.0 - 2.1 Ga grains is currently unknown and the 0.8 - 1.2 Ga grains are interpreted to reflect Mesoproterozoic Laurentian tectonism. Sediment input varied in response to sea level fluctuations. Longshore transport was likely an important process in redistributing grains along the coastline during later deposition of the Swan Peak Quartzite.
25

Plant communities of the grassy balds of Marys Peak, Oregon

Snow, Billy Douglas 26 April 1984 (has links)
Graduation date: 1984
26

The Relationship Between Stimulus Equivalence and Psychological Flexibility

Marshall, Anna 01 May 2016 (has links)
Psychological flexibility has been identified as an important construct within Relational Frame Theory and the examination of third-wave behavioral therapies. While psychological flexibility is defined within the context of relational responding, there is no research that directly assesses its relationship to measures of equivalence. The current study examined the relationship between PEAK Equivalence Pre-Assessment and scores of psychological inflexibility (via the AFQ-Y) in school-aged children with disabilities. Pearson correlations were utilized to examine the relationships between scores on PEAK and the AFQ-Y, as well as to examine the correlations among PEAK subtests. A large negative and statistically significant correlation (r =-.64, p < .05) was found between measures of psychological inflexibility and PEAK equivalence scores. Correlations among PEAK Equivalence Pre-Assessment subtests were line with previous research by Dixon, Belisle, & Stanley (in review), providing additional information for the relationship among measured components of equivalence. These findings have implications for guiding educational and therapeutic intervention, as well as provide additional evidence of the utility of the PEAK Equivalence Module.
27

Determining Reliability Of The PEAK Assessment Tool Using Split Half Reliability

Mason, Haley Alissa 01 December 2015 (has links)
The present study looked at the internal reliability of the PEAK Relational Training Assessment, using a split-half method of measurement. The reliability of the assessment questions within each of the four factors, within the PEAK Relational Training Assessment was estimated through this process. Eighteen participants, between the ages of 26 months and ten years old were included in the study. All participants had been diagnosed with either a language based or developmental disability, including autism, seizure disorder, Down syndrome and related language disorders. The PEAK Relational Training Assessment (PEAK-D) was administered by a direct-care provider for each of the 18 participants and during standard instructional periods. Results indicate that for each of the 18 participants, there was a strong correlation between scores when one half of the items in each factor were compared to the remaining half. Results did show internal reliability for the PEAK-D when using split-half methodology.
28

Evaluating the Generalization Assessment of PEAK System: Comparisons with IQ and the Direct Training Assessment

Sweetman, Jaclene Annaliese 01 August 2015 (has links)
The present study sought to demonstrate research based evidence that the more time spent in ABA therapy resulted in a an increase in IQ scores for participants. The research also sought to demonstrate that the PEAK Relational Training System can be effective as a treatment package. Previous research has evaluated the direct training protocol of the PEAK Relational Training System. The present study looked to evaluate the generalizing training protocols within the PEAK System, as well as support these previous findings. In Experiment 1 a quasi-experimental design was implemented and both control and treat-ment groups were exposed to testing measures. Results demonstrated greater gains made by the treatment group. Experiment 2 utilized a multiple baseline design across partici-pant and three designated generalized training programs from the PEAK System. Results showed a positive correlation between the PEAK Relational Training System and the par-ticipant’s IQ scores.
29

Further Examination of the Relationship Between Stimulus Equivalence and Psychological Flexibility

Erffmeyer, Julie Anne 01 August 2016 (has links)
Research surrounding psychological flexibility has begun to develop in recent decades. It has proven to be an important construct within the examination of third wave behavioral therapies and Relational Frame Theory. Though defined within the context of relational responding, there is little research directly assessing the relationship of psychological flexibility to measures of equivalence. The current study compared the scores of the PEAK Equivalence Pre-Assessment (to measure equivalence) and the scores from the AFQ-Y (to measure psychological inflexibility) to examine this relationship in school-aged children with ASD. The relationship between the total scores of the PEAK assessment and the scores of the AFQ-Y was examined by using a Pearson correlation. Results showed a statistically significant negative correlation (r = -.63, p<.05) between these measures. A Pearson correlation was then also used to examine the correlations among the PEAK subtests. As anticipated, the results showed a significant positive correlation among each of the components of equivalence providing additional information regarding the relationship among measured components of equivalence. These findings support recent research, and can help guide future educational and therapeutic interventions. Keywords: Autism (ASD), equivalence, PEAK, psychological flexibility
30

Teaching Equivalence Relations through Drawing using the PEAK-E Curriculum

Williams, Hailey Elizabeth 01 August 2016 (has links)
AN ABSTRACT OF THE THESIS OF Hailey Williams, for the Master’s Degree in Behavior Analysis, presented on 7/8/16, at Southern Illinois University Carbondale. TITLE: TEACHING EQUIVALENCE RELATIONS THROUGH DRAWING USING THE PEAK-E CURRICULUM MAJOR PROFESSOR: Dr. Mark R. Dixon The purpose of this study was to observe the formation of equivalence response classes using drawing to demonstrate the transformation of stimulus function from arbitrary textual words to simple drawings. Two children with Autism were taught directly trained relations, which paired together three stimuli from three separate class formations. The children were taught to relate A-B and B-C relations in trial blocks, and then tested with B-A and C-A relations. This train-test method was used to see if derived relations had emerged. Both participants demonstrated adequate learning in achieve mastery criteria in all the directly trained and derived relations from this study. The data is represented in a multiple baseline graph with an embedded multiple probe design. The outcome of this study indicates that the use of drawing and other creative behaviors have value in both relation frame theory and PEAK. There are also several implications of the study addressed here, including drawing as a verbal behavior and the role of internal events and covert behaviors in learning.

Page generated in 0.0544 seconds