• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1314
  • 371
  • 195
  • 155
  • 74
  • 59
  • 42
  • 24
  • 23
  • 21
  • 17
  • 17
  • 17
  • 17
  • 17
  • Tagged with
  • 2841
  • 1134
  • 564
  • 382
  • 319
  • 264
  • 243
  • 236
  • 228
  • 224
  • 223
  • 203
  • 197
  • 182
  • 155
  • 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.
31

Impact of Training Method on Behavioral, Physiological, and Relationship Measures in Horses

Isernia, Lindsay Taylor 07 January 2021 (has links)
With a rise in concern for animal welfare, the equine world has started using positive reinforcement (R+); as such, horses often experience a combination of negative reinforcement (R-) and R+. I compared the effects of R- to a combination of positive and negative reinforcement (R-/R+) training. Horses were trained to walk across two visually discriminable liverpools (striped, Experiment 1; colored water, Experiment 2), each associated with either R- or R-/R+, and training type alternating across six days. I measured highest training criteria reached, prevalence of undesirable behaviors, salivary cortisol (pre- and post-training), time spent by the trainer in motionless human tests (pre- and post-training), and horses' preference for the two liverpools using concurrent choice. Across both experiments, I found no significant difference in the proportions of criteria reached between training types; horses engaged in mugging for longer periods of time in R-/R+ than R-; no significant difference between training types for the pre- to post-change of cortisol; a greater proportion of horses increased time spent with R-/R+ trainer than the R- trainer; and no difference between first choice in the preference test or time horses spent in proximity to the liverpool, based on the training type with which the liverpool was associated. Overall, I found few differences between R-/R+ and R-, which could be due to horses only having 30 min total training contact with either training, or my use of relatively low intensities of R- and R+. / Master of Science / The equine world has started using positive reinforcement (R+), such as providing treats. Often horses experience a combination of negative reinforcement (R-) and R+, such as having rein pressure released and being given a treat. I compared effects of R- to a combination of positive and negative reinforcement (R-/R+) training. Horses were trained to walk across two visually distinct liverpools, a 1 m X 2.7 m shallow pool, (striped, Experiment 1; colored water, Experiment 2) each associated with either R- or R-/R+, and training type alternating across six days. I measured highest training level reached, occurrence of undesirable behaviors, salivary cortisol (a measure of stress), time spent by the trainer in motionless human tests, and horses' preference for the two liverpools. Across both experiments, I found no significant difference in the proportions of criteria reached between training types; horses investigated the trainer for treats for longer durations in R-/R+ than R-; no significant difference between training types for the pre- to post-change; a greater proportion of horses increased time spent with R-/R+ trainer than R- trainer; and no difference between first choice in the preference test or time horses spent in proximity to the liverpool, based on the training type with which the liverpool was associated. Overall, I found few differences between R-/R+ and R-, which could be due to horses only having 30 min total training contact with either training, or my use of relatively low intensities of R- and R+.
32

Order effects of variability-contingent and variability-independent point delivery: Effects on operant variability and target sequence acquisition.

Lee, Coral Em 05 1900 (has links)
Previous research has shown that variability is a reinforceable dimension of operant behavior. Additionally, it has been demonstrated that learning is facilitated when variability in responding is high. In this research, variability was observed within an operant composed of any sequence of six left and right key presses. Variability was either a requirement for point delivery (VAR conditions) or points were delivered independent of variability (ANY conditions). Two groups of college undergraduates experienced different orders of conditions. One group began the experiment under VAR conditions, and the variability requirement was later removed. The other group began the experiment under ANY conditions, and the variability requirement was later added. A concurrently reinforced target sequence (i.e., an always-reinforced sequence of left and right key presses) was introduced to both groups after these orders of conditions had been experienced. A variety of outcomes resulted. Subjects learned the target sequence when variability was both high and low with non-target points concurrently available. Other subjects learned the target sequence after all non-target point deliveries had been suspended. One subject failed to acquire the target sequence at all. These results were compared to previous findings and possible explanations for the discrepancies were suggested.
33

The Use of Conjugate Reinforcement in Autism Treatment Programs: a Demonstration and Discussion

Reetz, Stephany Kristina 12 1900 (has links)
The effect of a reinforcer on behavior is largely determined by the schedule in which it is implemented. One type of reinforcement schedule that has not been explored extensively is conjugate reinforcement. Previous researchers have used conjugate schedules to evaluate a reinforcer's effects on behavior and as an assessment tool. However, none have explored how to effectively engineer conjugate schedules in applied settings. The current study explores the effectiveness of conjugate reinforcement implemented by several interventionists across a variety of responses, reinforcers, and in a wide range of participants with autism. The results indicated that delivering social, audio/visual, and tangible stimuli in a conjugate schedule resulted in increased durations of various target responses (e.g. social skills, motor skills) and non-targeted measures (e.g., approach, social bids, speed) across participants. Considerations regarding reinforcer and response selection in implementing conjugate schedules in applied settings are provided.
34

The assessment of preference for qualitatively different reinforcers in persons with developmental and learning disabilities a comparison of value using behavioral economic and standard preference assessment procedures /

Bredthauer, Jennifer Lyn. Johnston, James M., January 2009 (has links)
Thesis (Ph. D.)--Auburn University. / Abstract. Includes bibliographical references (p. 148-163).
35

Verbal conditioning and extinction as a function of operant level, number of verbal responses, and type of reinforcement

Ware, Mark Edward. January 1966 (has links)
LD2668 .T4 1966 W271 / Master of Science
36

Transfer in reinforcement learning

Alexander, John W. January 2015 (has links)
The problem of developing skill repertoires autonomously in robotics and artificial intelligence is becoming ever more pressing. Currently, the issues of how to apply prior knowledge to new situations and which knowledge to apply have not been sufficiently studied. We present a transfer setting where a reinforcement learning agent faces multiple problem solving tasks drawn from an unknown generative process, where each task has similar dynamics. The task dynamics are changed by varying in the transition function between states. The tasks are presented sequentially with the latest task presented considered as the target for transfer. We describe two approaches to solving this problem. Firstly we present an algorithm for transfer of the function encoding the stateaction value, defined as value function transfer. This algorithm uses the value function of a source policy to initialise the policy of a target task. We varied the type of basis the algorithm used to approximate the value function. Empirical results in several well known domains showed that the learners benefited from the transfer in the majority of cases. Results also showed that the Radial basis performed better in general than the Fourier. However contrary to expectation the Fourier basis benefited most from the transfer. Secondly, we present an algorithm for learning an informative prior which encodes beliefs about the underlying dynamics shared across all tasks. We call this agent the Informative Prior agent (IP). The prior is learnt though experience and captures the commonalities in the transition dynamics of the domain and allows for a quantification of the agent's uncertainty about these. By using a sparse distribution of the uncertainty in the dynamics as a prior, the IP agent can successfully learn a model of 1) the set of feasible transitions rather than the set of possible transitions, and 2) the likelihood of each of the feasible transitions. Analysis focusing on the accuracy of the learned model showed that IP had a very good accuracy bound, which is expressible in terms of only the permissible error and the diffusion, a factor that describes the concentration of the prior mass around the truth, and which decreases as the number of tasks experienced grows. The empirical evaluation of IP showed that an agent which uses the informative prior outperforms several existing Bayesian reinforcement learning algorithms on tasks with shared structure in a domain where multiple related tasks were presented only once to the learners. IP is a step towards the autonomous acquisition of behaviours in artificial intelligence. IP also provides a contribution towards the analysis of exploration and exploitation in the transfer paradigm.
37

Reinforcer representations in Pavlovian conditioning

Stanhope, Kelly Jean January 1988 (has links)
No description available.
38

PIMOZIDE ALTERS HEDONIC, BUT NOT MOTOR SUBSTRATES OF RESPONDING (DOPAMINE, REWARD, RATS).

Bailey, Catherine Suzanne, 1958- January 1985 (has links)
No description available.
39

Modelling the electrochemical rehabilitation of chloride contaminated reinforced concrete bridge structures

Cromie, James Alexander January 1998 (has links)
No description available.
40

Finite element studies of reinforced embankments on soft ground

Kwok, C. M. January 1987 (has links)
No description available.

Page generated in 0.1105 seconds