Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.A.)--University of North Carolina at Wilmington, 2007. / Includes bibliographical references (leaves: 92-105)

Utilizing game theory, learning automata and reinforcement learning concepts, thesis presents a computational model (simulation) based on general equilibrium theory and classical monetary model. Model is based on interacting Constructively Rational agents. Constructive Ratio- nality has been introduced in current literature as machine learning based concept that allows relaxing assumptions on modeled economic agents information and ex- pectations. Model experiences periodical endogenous crises (Fall in both production and con- sumption accompanied with rise in unemployment rate). Crises are caused by firms and households adopting to a change in price and wage levels. Price and wage level adjustments are necessary for the goods and labor market to clear in the presence of technological growth. Finally, model has good theoretical background and large potential for further de- velopment. Also, general properties of games of learning entities are examined, with special focus on sudden changes (shocks) in the game and behavior of game's play- ers, during recovery from which rigidities can emerge. JEL Classification D80, D83, C63, E32, C73, Keywords Learning, Information and Knowledge, Agent-based, Reinforcement learning, Business cycle, Stochastic and Dynamic Games, Simulation, Modeling Author's e-mail...

An adage posits that we learn from our mistakes; however, this is not entirely true. According to reinforcement learning theory, we learn when the expectation of our actions differs from outcomes. Here, we examined whether expectancy driven learning lends a role in motor learning. Given the vast amount of overlapping anatomy and circuitry within the brain with respect to reward and motor processes, it is appropriate to examine both motor control and expectancy processes within a singular task. In the current study, participants performed a line drawing task via tablet under conditions of changing expectancies. Participants were provided feedback in a reinforcement-learning manner, as positive (✓) or negative (x) based off their performance. Modulation of expected outcomes were reflected by changes in amplitude of the human event-related potential (ERP), the reward positivity. The reward positivity is thought to reflect phasic dopamine release from the mesolimbic dopaminergic system to the basal ganglia and cingulate cortex. Due to the overlapping circuitry of reward and motor pathways, another human ERP, the bereitschatftspotential (BP), was examined. The BP is implicated in motor planning and execution; however, the late aspect of the BP shares similarity with the contingent negative variability (CNV). Current evidence demonstrates a relationship between expectancy and reward positivity amplitude in a motor learning context, as well as modulation of the BP under difficult task conditions. Behavioural data supports prior literature and may suggest a connection between sensory motor prediction errors working in concert with reward prediction errors. Further evidence supports a frontal-medial evaluation system for motor errors. Additionally, results support prior evidence of motor plans being formed upon target observation and held in memory until motor execution, rather than their formation before movement onset. / Graduate

Three experiments arranged a concurrent chained schedule that probabilistically arranged reinforcement or extinction. In Experiments 1 and 2, the probability of obtaining food in the terminal link period, following a given left or right lever choice, was the complement of the probability that the initial link choice would produce a transition to the terminal link. Also, the probability of reinforcement in the terminal link was either signaled or unsignaled, depending upon condition. In Experiment 1, a steady-state environment kept the relative probabilities of reinforcement constant within-session and Experiment 2 varied the relative probabilities of reinforcement within-session. Experiment 3 arranged equal rates of terminal link transition to either a signaled-reinforcement or an unsignaled-reinforcement terminal link. The location of the signaled option and the relative probabilities of reinforcement changed within-session. The signaled option produced either a reinforcement-correlated terminal link stimulus (i.e., conditional reinforcement) or an extinction-correlated terminal link stimulus. The unsignaled alternative produced the same terminal link stimulus regardless of the outcome. Overall, Experiments 1 and 2 demonstrated that rats frequently favor the option providing higher rates of terminal link transition at the expense of the probability of terminal link unconditional reinforcement. However, in Experiment 2, this tendency was reduced when the probabilities of reinforcement were signaled, suggesting weak control by conditional reinforcement. Experiment 3 did not show preference for the reinforcement-correlated signaled option in rats. Rather, it appears overall preference was controlled by an avoidance of the extinction-correlated option.

The present study examined the effects of engagement in both low-preferred and high-preferred concurrent activities during self-control training, and determined the activities' differential effects on participants' tolerance to delayed reinforcement. Three children with autism were given a choice between a small immediate reinforcer and a large delayed reinforcer. During baseline, all three participants consistently selected the smaller reinforcer, and the immediate choice. Two training conditions, including a progressive delay to reinforcement with either a preferred or non-preferred concurrent activity, were first alternately and then simultaneously presented. Two of the three participants reversed response allocation from 100% for the sooner smaller reinforcer to over 90% for the larger later reinforcer, and maintained almost exclusive allocation for the preferred activity. All three participants increased delay tolerance by at least 250% of average natural baseline duration.

Study 1 evaluated the use of a behavioral skills training package (BST) to teach three adults with autism spectrum disorders job interview and conversation skills. Participants were asked to have a mock job interview and conversation with the researcher. Participants' behavior was scored according to the conversation and job interview task analyses. The BST package included instruction, modeling, rehearsal, feedback, and reinforcement. A dense or lean schedule of reinforcement was assigned to each social skill based on performance during baseline. Social skills increased for all three participants when the BST package was implemented. Study 2 evaluated if dense or lean schedules of reinforcement affect maintenance of social skills. Two participants from Study 1 participated. Participants' BST data from Study 1 was used as baseline, followed by a maintenance phase. During this phase no instruction, modeling, rehearsal, feedback, or reinforcement was provided. The effect of rate of reinforcement during baseline on maintenance was evaluated.

The need continues within the field of organizational behavior management for empirically valid and feasible interventions to assist organizations with producing desirable changes in the work behavior of employees. The present study sought to determine the utility of a procedure to identify preferred stimulus among employees and the effects of implementation of the preferred stimulus on employee performance. Baseline data was collected on the productivity of employees. Then, a preference assessment was administered to employees. The results of the preference assessment yielded a commonly preferred stimulus which was then implemented to test for an effect on employee task completion. Results indicated moderate increases in employee performance and support the use of preference assessments to identify effective reinforcers for employees.

Rock bolts have been extensively used as a support element in coal mines in the US for about 40 years. Longwall development and partial extraction room-and-pillar mining systems now rely heavily on fully-grouted roof bolts as the primary support with as needed inclined bolts, trusses, and cable bolts as secondary support. These two coal mining systems develop 3- and 4-way intersections during extraction processes. A study of Illinois (2004-2008) and US coal mines found that over 70% of roof falls occurred at intersections. It is therefore necessary to perform additional research in stress and displacement distributions around intersections and then design support systems to improve stability of intersections. This thesis research, in cooperation with a bolt supplier and NIOSH, analyses the stress and strain redistribution in and around intersections in typical lithologies in the Illinois Basin coal mines with the goal to develop a better understanding of failure initiation and propagation mechanisms with and without roof supports. Analyses were corroborated with field observations wherever possible. Non-linear continuum analyses using the Generalized Hoek-Brown failure criterion with rock mass properties is the foundation for these analyses. The first task (Task 1) toward these goals was to develop rock mass properties from available laboratory data using estimates of Geological Strength Index (GSI) for different lithologies. An important subtask was to perform an error analysis in estimates of rock mass properties assuming an amount of error in GSI estimates. Analyses and field observations were done for typical 4-way intersections at two mines in southern Illinois operating at depths of 150 m and 80 m, respectively in the No. 6 coal seam, which averages 1.8 m in thickness. Pre-mining horizontal stresses of 7.58 MPa and 4.13 MPa were applied in the E-W and N-S directions. These coal companies provided geologic logs and rock mechanics data for roof and floor strata. Rock mass engineering properties for different roof and floor lithologies were developed using estimated values of Geological Strength Index (GSI), and Hoek-Brown (H-B) rock mass failure parameters. A recent laboratory study provided normal and shear stiffness properties of the immediate roof interfaces within the bolting range of 1.8 m. MSHA-approved roof support plans were used for initial modeling. Short Encapsulation Pull Test (SEPT) data provided by bolt suppliers in the region were used to assign bolting system stiffness and strength parameters. Task 2 analyzed normal and shearing stresses and strains in and around mine intersections for typical pre-mining stress fields and then identified critical areas of failure initiation and progressive failure propagation. Failure initiation was hypothesized to occur for critical values of compressive (1 mm/m), tensile (0.5 mm/m), and shearing (0.5 mm/m) strains based on a review of laboratory stress-strain properties. This approach allows quantifying areas in and around an intersection where failures are likely to initiate with and without artificial supports. It computes three reinforcement factors with and without supports: reinforcement against tensile (RFT), compressive (RFC) and shearing (RFSS) strains. Task 3 assessed the performance of currently practiced roof support plans and identified where inadequacies exist and how they could be improved through spatial distribution of supports and their characteristics. Analyses were completed for two mines with one orientation of pre-mining horizontal stress field. The next logical step (Task 4) was to extend analyses in Task 3 to assess the effect of maximum compressive stress orientation in relation to entry direction (0o, 30o, 60o & 90o) and different cut sequences and their effect on changes in failure initiation and failure propagation mechanisms. Numerical analyses have shown that stress and strain distributions are significantly different when the cut sequence is included in models. For a horizontal stress ratio of two (2), the 60o orientation provided maximum stability. Separate models with all cuts excavated simultaneously corresponded well with the well-established NIOSH software AHSM and previous research. The effect of cut sequence combined with the directional effect of pre-mining stresses becomes evident from the dissimilar results. A separate statistical study was conducted on 211 SEPT test data provided by a roof support manufacturer and marketing company in the region. Goals were to analyze the database for grip factor (GF) and anchorage stiffness (AS) characteristics using histograms and frequency distributions and, perform regression analyses to relate GF and AS values on the basis of height above coal seam and bolt diameter. Results were used for one stochastic run with variable GF and AS values assigned to different bolts in a roof control plan. Results indicated Gamma distribution best fitted AS and GF data. It was thought that the reinforcement factor for such a bolting layout would be more realistic than assigning a single value of GF and AS to bolts in the model.