Designing entertaining games requires control over the difficulty experienced by players. Gameplay has a clear impact on the difficulty and as such is easy to handle but other factors such as graphics do not share this clear cut impact. Therefore a game was made with adjustable graphical settings without changing any game elements in order to evaluate the effect on 18 participants. No effect was found for the measured performance but a weak correlation is possible for perceived difficulty.

This thesis addresses two important aspects of automatic assembly viz., assembly sequence planning and assembly path planning. These issues are addressed separately starting with sequence planning followed by assembly path planning. For efficient assembly without feedback systems (or, passive assembly), an assembler should know the ideal orientation of each component and the order in which to put the parts together (or, assembly sequence). A heuristic is presented to find the optimal assembly sequence and prescribe the orientation of the components for a minimum set of grippers = ideally one. The heuristic utilizes an index of difficulty (ID) that quantifies assembly. The ID for each task in the assembly process is computed on the basis of a number of geometrical and operational properties. The objective of the optimization problem here is to minimize the assembly ID and categorize parts/subassemblies based on their preferred direction of assembly while allowing re-orientation of the base part. It is assumed that the preferred direction of assembly is vertically downward, consistent with manual as well as most automatic assembly protocols. Our attempt is to minimize the number of degrees of freedom required in a re-orienting fixture and derive the requirements for such a fixture. The assembly of a small engine is used as an example in this study due to the variety of ideally rigid parts involved. In high precision assembly tasks, contact motion is common and often desirable. This entails a careful study of contact states of the parts being assembled. Recognition of contact states is crucial in planning and executing contact motion plans due to inevitable uncertainties. Dr. Jing Xiao of UNCC introduced the concept of principal contacts (PC) and contact formation (CF) for contact state recognition. The concept of using CFs (as sets of PCs) has the inherent advantage that a change of CF is often coincident with a discontinuity of the general contact force (force and torque). Previous work in contact motion planning has shown that contact information at the level of PCs along with the sensed location and force information is often sufficient for planning high precision assembly operations. In this thesis, we present results from experiments involving planned contact motions to validate the notion of PCs and CFs -- an abrupt change in general contact force often accompanies a change between CFs. We are only concerned with solving the 2D peg-in-corner problem. / Master of Science

Management control systems perform a vital role in facilitating the accomplishment of organizational objectives. To effectively align the objectives of employees with those of the organization, firms balance multiple control mechanisms to encourage organizationally desired behaviors and discourage undesired behaviors. The purpose of my dissertation was two-fold. First, I assessed how changes in monitoring frequency influenced employee behaviors and the overall function of the management control system. Second, I investigated the effects of stretch goals on behavior to determine whether stretch goals can lead to harmful behaviors and whether continuous monitoring can mitigate these behaviors. Results suggest that individuals exert more effort when assigned a stretch or difficult goal compared to an easy goal. My study also finds that stretch goals can be harmful because of their effect on risk taking, goal commitment, and job insecurity. Finally, results indicate that accountability mediates the monitoring frequency-risk taking relationship such that continuous monitoring increases accountability and accountability decreases risk taking. However, the ability of monitoring frequency to decrease risk taking may depend on numerous factors. Results from this study allow practitioners to understand the potential benefits and drawbacks of implementing continuous monitoring systems and the combined effects of using these systems in conjunction with compensation systems. Consequently, this study highlights necessary considerations for practitioners during the implementation continuous monitoring systems. The study also informs practitioners of the potentially harmful effects of stretch goals, the conditions under which they occur, and the possible ways to mitigate these effects.

Within an achievement motivation theoretical framework, there are factors thought to most heavily influence performance and task difficulty selection. More specifically, motivational climates, feedback, confidence, and anxiety have all been identified as important factors influencing outcomes within performance settings. Much of the literature in the area of achievement motivation has focused on on the effects of mastery- and ego-oriented feedback on performance within academic settings and has received limited attention in the sport psychology literature within an athletic setting. Given the demonstrated effects of mastery- and ego-oriented feedback on performance, the importance of performance within the athletic context, and the scant literature examining the effects of feedback on athletic performance, the influence of feedback on sport performance needed to be empirically examined. The primary aim of this study was to provide a clearer understanding of the relationship of factors influencing athletic performance, with the ultimate goal of moving research toward a greater understanding of how optimal performance is achieved. As a result, this research may prove applicable to researchers, coaches, and athletes working toward optimal performance. In this study, I examined how mastery- and ego-oriented feedback influenced youth athletes' soccer performance, task difficulty selection, confidence, and anxiety. Youth soccer athletes (n = 71) participated in a soccer kicking task consisting of two trials. Between subjects ANCOVA analyses revealed athletes receiving mastery-oriented feedback performed significantly better on the soccer kicking task than athletes receiving ego-oriented feedback. No differences were discovered on task difficulty selection, confidence, or anxiety. Providing athletes mastery-oriented feedback before or after skill execution could be helpful in the development of athletic skill development and performance. Limitations of the present study and questions to examine in future research are also discussed.

O objetivo do presente trabalho foi investigar os efeitos da interferência contextual em função das dificuldades funcional e nominal da tarefa. Participaram do estudo 160 adultos de ambos os sexos. Os participantes divididos em grupos de experientes e inexperientes praticaram uma tarefa simples ou complexa de timing coincidente, sob regime aleatório ou por blocos, totalizando oito grupos experimentais. As medidas de desempenho foram os erros absoluto, variável e constante. Os resultados não mostraram diferenças entre os grupos de prática aleatória e por blocos em nenhuma das condições de dificuldade (nominal e funcional). Sendo assim, concluiu-se que o efeito da interferência contextual não é dependente das dificuldades funcional e nominal da tarefa / The objective of this study was to investigate the effect of contextual interference due to the lack of functional and nominal task. The study included 160 adults of both sexes. Participants were divided in groups of experience and inexperience, which performed a simple or complex task of coincident timing, under random or blocked schedule. It resulted in eight experimental groups. Performance measures were the absolute, variable, and constant errors. Results did not show differences between random and blocked groups in all conditions of difficult (nominal and functional). Therefore, it was conclude that the effect of contextual interference is not dependent of the nominal and functional difficulties of the task

Concentration problems have been discussed from a variety of angles and have been problemized in different ways. One approach is to place the major part of the problem on the child independent of its environment. The terms used as an explanatory model are “attention disorder, impulsiveness, difficulty at finding suitable activity levels, difficulty in understanding rules and instructions” (Kadesjö 2007). Others place the root of the problem in the environment prevalent at pre-school and school. In this case the prevailing arguments are aimed at the pedagogical environment and the organisation of time and space (Nordin-Hultman 2005). My experience is that independent of reasons these children struggle, but often feel quite inadequate. The aim of this study is to examine how special pedagogues argue and problemize the concept of concentration difficulties. I also want to examine if there is anyway to reason and act in a way which will aid children with concentration difficulties, what that work would be and how a pedagogue can be a resource. The main result of my study is that the concentration problems found among the individuals I examined are relatively common in pre-school and school. The results regarding attitude and pedagogical methods can be summarized by the concept that pedagogical methods should be adapted to the individual.

No description available.

O objetivo do presente trabalho foi investigar os efeitos da interferência contextual em função das dificuldades funcional e nominal da tarefa. Participaram do estudo 160 adultos de ambos os sexos. Os participantes divididos em grupos de experientes e inexperientes praticaram uma tarefa simples ou complexa de timing coincidente, sob regime aleatório ou por blocos, totalizando oito grupos experimentais. As medidas de desempenho foram os erros absoluto, variável e constante. Os resultados não mostraram diferenças entre os grupos de prática aleatória e por blocos em nenhuma das condições de dificuldade (nominal e funcional). Sendo assim, concluiu-se que o efeito da interferência contextual não é dependente das dificuldades funcional e nominal da tarefa / The objective of this study was to investigate the effect of contextual interference due to the lack of functional and nominal task. The study included 160 adults of both sexes. Participants were divided in groups of experience and inexperience, which performed a simple or complex task of coincident timing, under random or blocked schedule. It resulted in eight experimental groups. Performance measures were the absolute, variable, and constant errors. Results did not show differences between random and blocked groups in all conditions of difficult (nominal and functional). Therefore, it was conclude that the effect of contextual interference is not dependent of the nominal and functional difficulties of the task

No description available.

No description available.