This thesis investigates the effect of problem structure on performance and behavioural variety in group problem solving. In addition, it examines the effects of problem solving strategy in group problem solving. <br /><br /> Previous researchers have focused their efforts on individual problem solving with minimal reference to groups. This is due to difficulties such as the presence of distributed information, the coordination of people and the large scale of work that typified group problems. Specifically, the effect of problem structure in group problems has been rarely studied due to the absence of an encompassing theory. <br /><br /> In this thesis, the effect of problem structure on group performance is studied using the fundamental characteristics of structure such as detour, redundancy, abstraction and degree of homogeneity. These characteristics were used in conjunction with existing problem solving theories (such as Information processing system, Gestalt approach and Lewin's lifespace approach) and Heider's balance theory to understand the effects of task structure on group performance and behavioural output. <br /><br /> Balance theory is introduced as a conceptual framework in which the problem solving process is viewed as a dynamic progression from cognitive imbalance towards a state of structural balance corresponding with the solution. This theoretical approach captures both incremental search processes and insight associated with cognitive restructuring, typical of existing problem solving approaches in the literature. It also allowed the development of unique measures for studying the effect of structure in group problem solving. <br /><br /> A Laboratory experiment was conducted using 153 undergraduate and 3 graduate students in groups of 4 subjects. The experiment examined the effect of task structure on groups' performance and behavioural variety. The stimulus used for the experiment was a categorization problem consisting of sixteen cards with two objects each shared equally among four participants. The objective was to form four groups of items with no cards left unused. The groups' performance data was collected and analyzed to verify the postulated hypotheses. <br /><br /> The results indicate that both increased problem structure complexity and the introduction of a restructuring dimension in the problem structure were associated with reduced performance and increased behavioural variety. With respect to problem solving strategy, early discussion in problem solving was associated with better performance and less behavioural variety. Finally, the results support the premise that group problem solving processes tend to be in the direction of attaining higher states of balance.

Two questions can be posed for study: 1) Will the effect of auditory masking provided by a clinical noise significantly affect the performance of hearing children on the Knox Cube Test? 2) Are there significant differences among brain-injured, mentally, retarded, and "normal" children in ability to adjust to auditory masking in the performance of the Knox Cube Test?

The aim of this study was to investigate the effects of acute stress on parallel task performance with the Game of Dice Task (GDT) to measure decision making and the Stroop test.  Two previous studies have found that the combination of stress and a parallel task with the GDT and an executive functions task preserved performance on the GDT for a stress group compared to a control group.  The purpose of this study was to create and use a new parallel task with the GDT and the stroop test to elucidate more information about the executive function contributions from the stroop test and to ensure that this parallel task preserves performance on the GDT for the stress group.  Sixteen participants (Mean Age: 26.88) were randomly assigned to either a stress group with the Trier Social Stress Test (TSST) or the control group with the placebo-TSST.  The Positive and Negative Affect Schedule (PANAS) and the State-Trait Anxiety Inventory (STAI) were given before and after the TSST or placebo-TSST and were used as stress indicators.  The results showed a trend towards the stress group performing marginally better than the control group on the GDT but not significantly.  There were no significant differences between the groups for accuracy on the Stroop test trial types.  However, the stress group had significantly slower mean response times on the congruent trial type of the Stroop test, p &lt; .05, though.  This study has shown further evidence that stress and a parallel task together preserve performance on the GDT.

In this paper we propose an architecture for a new task-level system, which we call TWAIN. Task-level programming attempts to simplify the robot programming process but requiring that the user specify only goals for the physical relationships among objects, rather than the motions needed to achieve those goals. A task-level specification is meant to be completely robot independent; no positions or paths that depend on the robot geometry or kinematics are specified by the user. We have two goals for this paper. Th is first is to present a more unified t reatment of some individual pieces of r esearch in task planning, whose r elationship has not previously been d escribed. The second is to provide a new framework for further research in task-planning. This is a slightly modified version of a paper that appeared in Proceedings of Soli d Modeling by Computers: from Theory to A pplications, Research laboratories Sympo sium Series, sponsored by General Motors, Warren, Michigan, September 1983.

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This thesis investigates the effect of problem structure on performance and behavioural variety in group problem solving. In addition, it examines the effects of problem solving strategy in group problem solving. <br /><br /> Previous researchers have focused their efforts on individual problem solving with minimal reference to groups. This is due to difficulties such as the presence of distributed information, the coordination of people and the large scale of work that typified group problems. Specifically, the effect of problem structure in group problems has been rarely studied due to the absence of an encompassing theory. <br /><br /> In this thesis, the effect of problem structure on group performance is studied using the fundamental characteristics of structure such as detour, redundancy, abstraction and degree of homogeneity. These characteristics were used in conjunction with existing problem solving theories (such as Information processing system, Gestalt approach and Lewin's lifespace approach) and Heider's balance theory to understand the effects of task structure on group performance and behavioural output. <br /><br /> Balance theory is introduced as a conceptual framework in which the problem solving process is viewed as a dynamic progression from cognitive imbalance towards a state of structural balance corresponding with the solution. This theoretical approach captures both incremental search processes and insight associated with cognitive restructuring, typical of existing problem solving approaches in the literature. It also allowed the development of unique measures for studying the effect of structure in group problem solving. <br /><br /> A Laboratory experiment was conducted using 153 undergraduate and 3 graduate students in groups of 4 subjects. The experiment examined the effect of task structure on groups' performance and behavioural variety. The stimulus used for the experiment was a categorization problem consisting of sixteen cards with two objects each shared equally among four participants. The objective was to form four groups of items with no cards left unused. The groups' performance data was collected and analyzed to verify the postulated hypotheses. <br /><br /> The results indicate that both increased problem structure complexity and the introduction of a restructuring dimension in the problem structure were associated with reduced performance and increased behavioural variety. With respect to problem solving strategy, early discussion in problem solving was associated with better performance and less behavioural variety. Finally, the results support the premise that group problem solving processes tend to be in the direction of attaining higher states of balance.

As the speed of integrated circuits increases, so does their power consumption. Most of this power is turned into heat, which must be dissipated effectively in order for the circuit to avoid thermal damage. Thermal control therefore has emerged as an important issue in design and management of circuits and systems. Dynamic speed scaling, where the input power is temporarily reduced by appropriately slowing down the circuit, is one of the major techniques to manage power so as to maintain safe temperature levels. In this study, we focus on thermally-constrained hard real-time systems, where timing guarantees must be met without exceeding safe temperature levels within the microprocessor. Speed scaling mechanisms provided in many of today’s processors provide opportunities to temporarily increase the processor speed beyond levels that would be safe over extended time periods. This dissertation addresses the problem of safely controlling the processor speed when scheduling mixed workloads with both hard-real-time periodic tasks and non-real-time, but latency-sensitive, aperiodic jobs. We first introduce the Transient Overclocking Server, which safely reduces the response time of aperiodic jobs in the presence of hard real-time periodic tasks and thermal constraints. We then propose a design-time (off-line) execution-budget allocation scheme for the application of the Transient Overclocking Server. We show that there is an optimal budget allocation which depends on the temporal character istics of the aperiodic workload. In order to provide a quantitative framework for the allocation of budget during system design, we present a queuing model and validate the model with results from a discrete-event simulator. Next, we describe an on-line thermally-aware transient overclocking method to reduce the response time of aperiodic jobs efficiently at run-time. We describe a modified Slack-Stealing algorithm to consider the thermal constraints of systems together with the deadline constraints of periodic tasks. With the thermal model and temperature data provided by embedded thermal sensors, we compute slack for aperiodic workload at run-time that satisfies both thermal and temporal constraints. We show that the proposed Thermally-Aware Slack-Stealing algorithm minimizes the response times of aperiodic jobs while guaranteeing both the thermal safety of the system and the schedulability of the real-time tasks. The two proposed speed control algorithms are examples of so-called proactive schemes, since they rely on a prediction of the thermal trajectory to control the temperature before safe levels are exceeded. In practice, the effectiveness of proactive speed control for the thermal management of a system relies on the accuracy of the thermal model that underlies the prediction of the effects of speed scaling and task execution on the temperature of the processor. Due to variances in the manufacturing of the circuit and of the environment it is to operate, an accurate thermal model can be gathered at deployment time only. The absence of power data makes a straightforward derivation of a model impossible. We, therefore, study and describe a methodology to infer efficiently the thermal model based on the monitoring of system temperatures and number of instructions used for task executions.

Thesis (Ph. D.)--University of Queensland, 2001. / Includes bibliographical references.

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