897 resultados para Self-control.
Centralized Motion Control of a Linear Tooth Belt Drive: Analysis of the Performance and Limitations
Resumo:
A centralized robust position control for an electrical driven tooth belt drive is designed in this doctoral thesis. Both a cascaded control structure and a PID based position controller are discussed. The performance and the limitations of the system are analyzed and design principles for the mechanical structure and the control design are given. These design principles are also suitable for most of the motion control applications, where mechanical resonance frequencies and control loop delays are present. One of the major challenges in the design of a controller for machinery applications is that the values of the parameters in the system model (parameter uncertainty) or the system model it self (non-parametric uncertainty) are seldom known accurately in advance. In this thesis a systematic analysis of the parameter uncertainty of the linear tooth beltdrive model is presented and the effect of the variation of a single parameter on the performance of the total system is shown. The total variation of the model parameters is taken into account in the control design phase using a Quantitative Feedback Theory (QFT). The thesis also introduces a new method to analyze reference feedforward controllers applying the QFT. The performance of the designed controllers is verified by experimentalmeasurements. The measurements confirm the control design principles that are given in this thesis.
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Systems biology is a new, emerging and rapidly developing, multidisciplinary research field that aims to study biochemical and biological systems from a holistic perspective, with the goal of providing a comprehensive, system- level understanding of cellular behaviour. In this way, it addresses one of the greatest challenges faced by contemporary biology, which is to compre- hend the function of complex biological systems. Systems biology combines various methods that originate from scientific disciplines such as molecu- lar biology, chemistry, engineering sciences, mathematics, computer science and systems theory. Systems biology, unlike “traditional” biology, focuses on high-level concepts such as: network, component, robustness, efficiency, control, regulation, hierarchical design, synchronization, concurrency, and many others. The very terminology of systems biology is “foreign” to “tra- ditional” biology, marks its drastic shift in the research paradigm and it indicates close linkage of systems biology to computer science. One of the basic tools utilized in systems biology is the mathematical modelling of life processes tightly linked to experimental practice. The stud- ies contained in this thesis revolve around a number of challenges commonly encountered in the computational modelling in systems biology. The re- search comprises of the development and application of a broad range of methods originating in the fields of computer science and mathematics for construction and analysis of computational models in systems biology. In particular, the performed research is setup in the context of two biolog- ical phenomena chosen as modelling case studies: 1) the eukaryotic heat shock response and 2) the in vitro self-assembly of intermediate filaments, one of the main constituents of the cytoskeleton. The range of presented approaches spans from heuristic, through numerical and statistical to ana- lytical methods applied in the effort to formally describe and analyse the two biological processes. We notice however, that although applied to cer- tain case studies, the presented methods are not limited to them and can be utilized in the analysis of other biological mechanisms as well as com- plex systems in general. The full range of developed and applied modelling techniques as well as model analysis methodologies constitutes a rich mod- elling framework. Moreover, the presentation of the developed methods, their application to the two case studies and the discussions concerning their potentials and limitations point to the difficulties and challenges one encounters in computational modelling of biological systems. The problems of model identifiability, model comparison, model refinement, model inte- gration and extension, choice of the proper modelling framework and level of abstraction, or the choice of the proper scope of the model run through this thesis.
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The assembly and maintenance of the International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV) is highly challenging since the tasks performed by the robot involve welding, material handling, and machine cutting from inside the VV. The VV is made of stainless steel, which has poor machinability and tends to work harden very rapidly, and all the machining operations need to be carried out from inside of the ITER VV. A general industrial robot cannot be used due to its poor stiffness in the heavy duty machining process, and this will cause many problems, such as poor surface quality, tool damage, low accuracy. Therefore, one of the most suitable options should be a light weight mobile robot which is able to move around inside of the VV and perform different machining tasks by replacing different cutting tools. Reducing the mass of the robot manipulators offers many advantages: reduced material costs, reduced power consumption, the possibility of using smaller actuators, and a higher payload-to-robot weight ratio. Offsetting these advantages, the lighter weight robot is more flexible, which makes it more difficult to control. To achieve good machining surface quality, the tracking of the end effector must be accurate, and an accurate model for a more flexible robot must be constructed. This thesis studies the dynamics and control of a 10 degree-of-freedom (DOF) redundant hybrid robot (4-DOF serial mechanism and 6-DOF 6-UPS hexapod parallel mechanisms) hydraulically driven with flexible rods under the influence of machining forces. Firstly, the flexibility of the bodies is described using the floating frame of reference method (FFRF). A finite element model (FEM) provided the Craig-Bampton (CB) modes needed for the FFRF. A dynamic model of the system of six closed loop mechanisms was assembled using the constrained Lagrange equations and the Lagrange multiplier method. Subsequently, the reaction forces between the parallel and serial parts were used to study the dynamics of the serial robot. A PID control based on position predictions was implemented independently to control the hydraulic cylinders of the robot. Secondly, in machining, to achieve greater end effector trajectory tracking accuracy for surface quality, a robust control of the actuators for the flexible link has to be deduced. This thesis investigates the intelligent control of a hydraulically driven parallel robot part based on the dynamic model and two schemes of intelligent control for a hydraulically driven parallel mechanism based on the dynamic model: (1) a fuzzy-PID self-tuning controller composed of the conventional PID control and with fuzzy logic, and (2) adaptive neuro-fuzzy inference system-PID (ANFIS-PID) self-tuning of the gains of the PID controller, which are implemented independently to control each hydraulic cylinder of the parallel mechanism based on rod length predictions. The serial component of the hybrid robot can be analyzed using the equilibrium of reaction forces at the universal joint connections of the hexa-element. To achieve precise positional control of the end effector for maximum precision machining, the hydraulic cylinder should be controlled to hold the hexa-element. Thirdly, a finite element approach of multibody systems using the Special Euclidean group SE(3) framework is presented for a parallel mechanism with flexible piston rods under the influence of machining forces. The flexibility of the bodies is described using the nonlinear interpolation method with an exponential map. The equations of motion take the form of a differential algebraic equation on a Lie group, which is solved using a Lie group time integration scheme. The method relies on the local description of motions, so that it provides a singularity-free formulation, and no parameterization of the nodal variables needs to be introduced. The flexible slider constraint is formulated using a Lie group and used for modeling a flexible rod sliding inside a cylinder. The dynamic model of the system of six closed loop mechanisms was assembled using Hamilton’s principle and the Lagrange multiplier method. A linearized hydraulic control system based on rod length predictions was implemented independently to control the hydraulic cylinders. Consequently, the results of the simulations demonstrating the behavior of the robot machine are presented for each case study. In conclusion, this thesis studies the dynamic analysis of a special hybrid (serialparallel) robot for the above-mentioned special task involving the ITER and investigates different control algorithms that can significantly improve machining performance. These analyses and results provide valuable insight into the design and control of the parallel robot with flexible rods.
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The reproductive biology of Capparis retusa was studied by means of controlled pollination experiments and fluorescence microscopy observations of post-pollination events. Self-pollinated flowers mostly failed to form fruits despite the fact that self-pollen tubes grew to the ovary and penetrated ovules within 24 h. Since embryo development to globular stage was observed in some self-fertilized ovules it was concluded that control of self-fertilization in this species occurs by some kind of post-zygotic mechanism.
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The context of this study is corporate e-learning, with an explicit focus on how digital learning design can facilitate self-regulated learning (SRL). The field of e-learning is growing rapidly. An increasing number of corporations use digital technology and elearning for training their work force and customers. E-learning may offer economic benefits, as well as opportunities for interaction and communication that traditional teaching cannot provide. However, the evolving variety of digital learning contexts makes new demands on learners, requiring them to develop strategies to adapt and cope with novel learning tools. This study derives from the need to learn more about learning experiences in digital contexts in order to be able to design these properly for learning. The research question targets how the design of an e-learning course influences participants’ self-regulated learning actions and intentions. SRL involves learners’ ability to exercise agency in their learning. Micro-level SRL processes were targeted by exploring behaviour, cognition, and affect/motivation in relation to the design of the digital context. Two iterations of an e-learning course were tested on two groups of participants (N=17). However, the exploration of SRL extends beyond the educational design research perspective of comparing the effects of the changes to the course designs. The study was conducted in a laboratory with each participant individually. Multiple types of data were collected. However, the results presented in this thesis are based on screen observations (including eye tracking) and video-stimulated recall interviews. These data were integrated in order to achieve a broad perspective on SRL. The most essential change evident in the second course iteration was the addition of feedback during practice and the final test. Without feedback on actions there was an observable difference between those who were instruction-directed and those who were self-directed in manipulating the context and, thus, persisted whenever faced with problems. In the second course iteration, including the feedback, this kind of difference was not found. Feedback provided the tipping point for participants to regulate their learning by identifying their knowledge gaps and to explore the learning context in a targeted manner. Furthermore, the course content was consistently seen from a pragmatic perspective, which influenced the participants’ choice of actions, showing that real life relevance is an important need of corporate learners. This also relates to assessment and the consideration of its purpose in relation to participants’ work situation. The rigidity of the multiple choice questions, focusing on the memorisation of details, influenced the participants to adapt to an approach for surface learning. It also caused frustration in cases where the participants’ epistemic beliefs were incompatible with this kind of assessment style. Triggers of positive and negative emotions could be categorized into four levels: personal factors, instructional design of content, interface design of context, and technical solution. In summary, the key design choices for creating a positive learning experience involve feedback, flexibility, functionality, fun, and freedom. The design of the context impacts regulation of behaviour, cognition, as well as affect and motivation. The learners’ awareness of these areas of regulation in relation to learning in a specific context is their ability for design-based epistemic metareflection. I describe this metareflection as knowing how to manipulate the context behaviourally for maximum learning, being metacognitively aware of one’s learning process, and being aware of how emotions can be regulated to maintain volitional control of the learning situation. Attention needs to be paid to how the design of a digital learning context supports learners’ metareflective development as digital learners. Every digital context has its own affordances and constraints, which influence the possibilities for micro-level SRL processes. Empowering learners in developing their ability for design-based epistemic metareflection is, therefore, essential for building their digital literacy in relation to these affordances and constraints. It was evident that the implementation of e-learning in the workplace is not unproblematic and needs new ways of thinking about learning and how we create learning spaces. Digital contexts bring a new culture of learning that demands attitude change in how we value knowledge, measure it, define who owns it, and who creates it. Based on the results, I argue that digital solutions for corporate learning ought to be built as an integrated system that facilitates socio-cultural connectivism within the corporation. The focus needs to shift from designing static e-learning material to managing networks of social meaning negotiation as part of a holistic corporate learning ecology.
Resumo:
Self-presentation is the process by which individuals attempt to monitor and control how others perceive and evaluate them (Leary, 1992; Leary & Kowalski, 1990). Self-presentational concerns have been shown to influence a number of exercise-related behaviours, cognitions, and affective responses to exercise (e.g., social anxiety). Social anxiety occurs when an individual wants to create a specific impression on others, but is unsure (s)he will be successful (Leary & Kowalski, 1995). Social physique anxiety (SPA) is a specific form of social anxiety related the evaluation of one's body (Hart, Leary, & Rejeski, 1989). Both social anxiety and SPA may act as deterrents to exercise (Lantz, Hardy, & Ainsworth, 1997; Leary, 1992), so it is important to examine factors that may influence social anxiety and SPA; one such factor is self-presentational efficacy (SPE). SPE is one's confidence in successfully making desired impressions on others (Leary & Atherton, 1986) and has been associated with social anxiety and SPA (Leary & Kowalski, 1995; Gammage, Martin Ginis, & Hall, 2004). Several aspects of the exercise environment, such as the presence of mirrors, clothing, and the exercise leader or other participant characteristics, may be manipulated to influence self-presentational concerns (e.g., Gammage, Martin Ginis et aI., 2004; Martin & Fox, 2001; Martin Ginis, Prapavessis, & Haase, 2005). Given that the exercise leader has been recognized as one of the most important influences in the group exercise context (Franklin, 1988), it is important to further examine how the leader may impact self-presentational concerns. The present study examined the impact of the exercise leader's gender and physique salience (i.e., the extent to which the body was emphasized) on SPE, state social anxiety (SSA), and state social physique anxiety (SPA-S) of women in a live exercise class. Eighty-seven college-aged female non- or infrequent exercisers (i.e., exercised 2 or fewer times per week) participated in a group exercise class led by one of four leaders: a female whose physique was salient; a female whose physique was non-salient; a male whose physique was salient; or a male whose physique was non-salient. Participants completed measures of SPE, SSA, and SPA-S prior to and following completion of a 30- minute group exercise class. In addition, a measure of social comparison to the exercise leader and other participants with respect to attractiveness, skill, and fitness was completed by participants following the exercise class. A MANOV A was conducted to examine differences between groups on postexercise variables. Results indicated that there were no significant differences between groups on measures ofSPE, SSA, or SPA-S (allp's > .05). However, when all participants were collapsed into one group, a MANOV A showed a significant time effect (F(3, 81) = 19.45,p < .05, 1')2= .419). Follow-up ANOVAs indicated that post-exercise SPE increased significantly, while SSA and SPA-S decreased significantly (SPE: F(I, 83) = 30.87,p < .001,1')2 = .27; SSA: F(I,83) = 11.09,p < .001, 1')2 = .12; SPA-S: F (1,83) = 42.79,p < .001, 1')2 = .34). Further, results of a MANOVA revealed that participants who believed they were less fit than other group members (i.e., made negative social comparisons) reported significantly more post-exercise SSA and SP A-S than those who believed they were more fit than the other participants (i.e., made positive comparisons; SSA: F(2, 84) = 3.46, p < .05, 1')2 = .08; SPA-S: F(2, 84) = 5.69, p < .05, 1')2 = .12). These results may indicate that successfully completing an exercise class may serve as a source of SPE and lead to reduced social anxiety and SPA-S in this population. Alternatively, characteristics of the exercise leader may be less important than characteristics of the other participants. These results also suggest that the types of social comparisons made may influence self-presentational concerns in this sample. Future research should examine how the type of social comparison (i.e., negative or positive) made to the other group members may either generate or reduce anxiety. Also, factors that contribute to the types of social comparisons made with other exercisers should be examined. Implications for practice and research are discussed.
Resumo:
Objective. Smoking prevalence is highest among the young adult cohort. Postsecondary students are no exception. Although many students intend to quit smoking, no research has established what methods best promote reductions in, or complete abstinence from smoking. This randomized controlled trial examined the effectiveness of three self-help smoking cessation interventions. Method. On six post-secondary campuses, 483 smokers who voluntarily accessed Leave The Pack Behind (a tobacco control initiative) were randomly assigned to one of three smoking cessation interventions: One Step At A Time (a 2-booklet, *gold standard' program for adults); Smoke|Quit (a newly-developed 2-booklet program for young adult students); and usual care (a 'Quit Kit' containing a booklet on stress management, information about pharmacological quitting aides and novelty items). All participants also received one proactive telephone support call from a peer counsellor. During the study, 85 participants withdrew. The final sample of 216 students who completed baseline questionnaires and 12-week follow-up telephone interviews was representative of the initial sample in terms of demographic characteristics, and smokingquitting- related variables. Results. Whether participants quit smoking depended upon treatment condition, ^(2, N=2\6) = 6.34, p = .04, with Smoke|Quit producing more successfijl quitters (18.4%) than One Step At A Time (4.5%) or the Quit Kit (1 1.4%). On average, participants had quit 53.46 days, with no significant difference across treatments. Selfefficacy also increased. Use of the intervention or other quitting aides was not associated with treatment condition. Among the 191 participants who did not quit smoking, treatment condition did not influence outcomes. Overall, 46.2% had made a quit attempt. Significant decreases in weekly tobacco consumption and increases in self-efficacy to resist smoking were observed from baseline to follow-up. Conclusion. Post-secondary institutions represent a potentially final opportunity for age-targeted interventions. Self-help resources tailored to students' social and contextual characteristics will have considerable more impact than stage-only tailored interventions. Both reduction and abstinence outcomes should be emphasized to positively support students to stop smoking.
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Despite the confimied health benefits of exercise during the postpartum period, many new mothers are not sufficiently active. The present research aimed to examine the effectiveness of 2 types of messages on intention to exercise after giving birth on 2 groups of pregnant women (low and high self-monitors) using the Theory of Planned Behavior as a theoretical basis. Participants were 2 1 8 pregnant women 1 8 years of age and older (Mean age = 27.9 years, SD = 5.47), and in their second or third trimester. Women completed a demographics questionnaire, a self-monitoring (SM) scale and the Godin Leisure Time Exercise Questionnaire for current and pre-pregnancy exercise levels. They then read one of two brochures, describing either the health or appearance benefits of exercise for postpartum women. Women's attitudes, social norms, perceived behavioral control, and intentions to exercise postpartum were then assessed to determine whether one type of message (health or appearance) was more effective for each group. A MANOVA found no significant effect (p>0.05) for message type, SM, or their interaction. Possible reasons include the fact that the two messages may have been too similar, reading any message about exercise may result in intentions to exercise, or lack of attention given to the brochure. Given the lack of research in this area, more studies are necessary to confirm the present results. Two additional exploratory analyses were conducted. Pearson correlations found higher levels of pre-pregnancy exercise and current exercise to be associated with more positive attitudes, more positive subjective norms, higher perceived behavioral control, and higher intention to exercise postpartum. A hierarchical regression was conducted to determine the predictive utility of attitudes, subjective norms, and perceived behavioral control on intention for each self-monitoring group. Results of the analysis demonstrated the three independent variables significantly predicted intention (p < .001) in both groups, accounting for 58-62% of the variance in intention. For low self-monitors, attitude was the strongest predictor of intention, followed by perceived behavioral control and subjective norm. For high self-monitors, perceived behavioral control was the strongest predictors, followed by attitudes and subjective norm. The present study has practical and real world implications by contributing to our understanding of what types of messages, in a brochure format, are most effective in changing pregnant women's attitudes, subjective norm, perceived behavioral control and intention to exercise postpartum and provides ftirther support for the use of the Theory of Planned Behavior with this population.
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~ This study focuses on the process of self-directed learning that individuals go through as they adapt to new work situations. This is a study of how one critical incident, specifically the transition from a traditional office structure to a home office structure, affected employees and what their learning process was as they adapted to the new environment. This study has 3 educational foundations: adult learning, self-directed learning, and the social context from which the learning will occur. Six women and 2 men were interviewed approximately 1 year following the transition. Analysis of the data revealed 5 themes of: impacts of the self-directed environment on participants' personal lives, their roles, skill set, productivity, and the physical environment; support offered by the organization, family, and office administration; personal development, specific learning needs, and personal skills; boundaries as they relate to family and work; and skill set and orientation requirements of new home office employees. The findings revealed the learning processes of the 8 participants. The learning processes of these participants were discussed within a theoretical framework of the learners, their immediate surroundings, and the larger social environment. The results indicated that the transition from a directed work environment to a self directed work environment is a complex, interrelated process. An element found throughout the theoretical framework is that of control. A second critical element is the need for participants to have a clearly defined work role and an opportunity to engage in discussion with peers and the community. Further findings reinforced the importance of climate and found that the physical environment is a key factor in a successful selfdirected work environment. The findings of this study revealed that no one factor makes an individual function successfully in a self-directed work environment, but that it is a complex interplay among the leamer, their immediate surroundings, and the social environment that will have the greatest impact on success. Recommendations are made which can be used to guide organizational leaders in facilitating employees' transition from a directed to a self-directed work environment. Additionally, recommendations are made for further research in the area of self-directed work environments.
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This study was an investigation of individual and organizational factors, as perceived by front-line vocational service workers from Adult Rehabilitation Centres (ARC Industries) for mentally retarded adults. The specific variables which were measured included role conflict/role ambiguity (role factors), internal/external locus of control (individual differences), job satisfaction with work and supervision (job attitudes) and participation in deci~ion making (organizational factor). The exploration of these constructs was conducted by means of self-report questionnaires which were completed by sixty-nine out of a total of ninety front-line employees. The surveys were distributed in booklet form to nine distinct rehabilitation facilities from St. Catharines, West Lincoln, Greater Niagara, Port Colborne, WeIland, Fort Erie, Hamilton, Guelph and Brantford. The survey data was evaluated by the statisti.cal Package for the Social Sciences (SPSS) which used the Pearson Product Moment Correlation procedure and a compar~son of means test. A comparison of correlation coefficients test was also conducted. This statistical procedure was calculated mathematically. The results obtained from the statistical evaluation confirmed the prediction that self-reported measures of participation in decision making and satisfaction (work and supervision) would be negatively correlated with role conflict and role ambiguity. As well, the speculation that perceived satisfaction (work and supervision) would be positively correlated with participation in decision making was empirically supported. Internal and external locus of control did not contribute to a significant difference in r~sponses to role perceptions (conflict and ambiguity) , satisfaction (work and supervision) or the correlational relationship between participation in decision making and satisfaction (work and supervision). Overall, the findings from this study substantiated the importance of examining employee perceptions in the workplace and the interrelationships among individual and organizational variables. This research was considered a contribution to the general area of occupational stress and to the study of individuals in work organizations.
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Ontario Colleges of Applied Arts and Technology (CAATs) are currently in the process of restructuring to ensure quality, accountability, and accessibility of college education. References to learner involvement and self-directed learning are prevalent. "Alternative delivery" and "paradigm shift" are current buzzwords within the Ontario CAAT system as an environment is created supportive of change. Instability of funding has also dictated a need for change. Therefore, a focus has become quality of learning with less demand on public resources. This qualitative case study was conducted at an Ontario CAAT to gather descriptive, perceptual data from post-secondary community college educators who were identified as supportive of self-directed learning and from post-secondary, traditional-aged college students who were perceived by their educators to be selfdirected learners. This college was selected because of initiatives to modify its academic paradigm to encourage what was reputed in the Ontario CAAT system to be self-directed learning. The purpose of this study was to investigate how postsecondary, traditional-aged college students and their educators perceive self-directed learning as part of the teaching-learning experience within a community college setting. Educator participants of the study were selected based on the results of a teaching and learning survey intended to identify educators supportive of self-directed learning. A total of 317 surveys were distributed to every full-time educator at the sample college; 192 completed surveys were returned for a return rate of 61 %. Of these, 8% indicated instructional beliefs and values supportive of self-directed learning. A purposive sample of six educators was selected using a maximulp variation sampling strategy. A network selection sampling strategy was used to select a purposive sample of seven post-secondary students who were identified by the sample educators as selfdirected learners. The results of the study show that students and educators have similar perspectives and operating definitions of self-directed learning and all participants believe they either practice or facilitate self-directed learning. However, their perspectives and practices are not consistent with the literature which emphasizes learner autonomy or control in course structure and content. A central characteristic of the participants represented in this study is the service-oriented professions with which each is associated. Experientiallearning opportunities were highly valued for the options provided in increasing learner independence and competencies in reflective practice. Although there were discrepancies between espoused theory and theory in practice in terms of course structure, the process of self-directed learning was being practiced and supported outside the classroom structure in clinical settings, labs and related experiences.
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The concept of self-directed learning was examined from the nurse educators' perspective. One structured interview, lasting between one and one-and-a half hours, was conducted with each of 14 nurse educators in two community college continuing education programs in nursing. One community college program encourages selfdirected learning; the other encourages self-study and active participation in the teaching/learning process. All 14 interviews were tape-recorded and transcribed verbatim. Verbatim transcripts were analyzed for themes, patterns, and relationships utilizing analyst-constructed typologies. six prerequisites or necessary conditions for facilitating self-directed learning in a community college continuing education program in nursing were identified. ~he crucial issue in facilitating self-directed learning was found to be the issue of teacher-control.
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The intent in this study was to investigate in what ways teachers· beliefs about education and teaching are expressed in the specific teaching behaviours they employ, and whether teaching behaviours, as perceived by their students, are correlated with students· critical thinking and self-directed learning. To this end the relationships studied were: among faCUlty members· philosophy of teaching, locus of control orientation, psychological type, and observed teaching behaviour; and among students· psychological type, perceptions of teaching behaviour, self-directed learning readiness, and critical thinking. The overall purpose of the study was to investigate whether the implicit goals of higher education, critical thinking and self-direction, were actually accounted for in the university classroom. The research was set within the context of path-goal theory, adapted from the leadership literature. Within this framework, Mezirow·s work on transformative learning, including the influences of Habermas· writings, was integrated to develop a theoretical perspective upon which to base the research methodology. Both qualitative and quantitative methodologies were incorporated. Four faCUlty and a total of 142 students participated in the study. Philosophy of teaching was described through faCUlty interviews and completion of a repertory grid. Faculty completed a descriptive locus of control scale, and a psychological type test. Observations of their teaching behaviour were conducted. Students completed a Teaching Behaviour Assessment Scale, the Self-Directed Learning Readiness Scale, a psychological type test, and the Watson-Glaser Critical Thinking Appraisal. A small sample of students were interviewed. Follow-up discussions with faculty were used to validate the interview, observation, teaching behaviour, and repertory grid data. Results indicated that some discrepancies existed between faculty's espoused philosophy of teaching and their observed teaching behaviour. Instructors' teaching behaviour, however, was a function of their personal theory of practice. Relationships were found between perceived teaching behaviour and students· self-directed learning and critical thinking, but these varied across situations, as would be predicted from path-goal theory. Psychological type of students and instructor also accounted for some of the variability in the relationships studied. Student psychological type could be shown as a partial predictor of self-directed learning readiness. The results were discussed in terms of theory development and implications for further research and practice.
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The present research study examined the relationships in a work motivation context among perceived importance and achievement of work values, locus of control and internal work motivation. The congruence of a work value was considered to be the discrepancy between the importance of a work value and the perceived achievement of that value. The theoretical framework utilized was based on a self-perpetuating cycle of motivation which included the perceived importance and achievement of work values and internal work motivation as separate and distinct, yet interrelated factors. It was hypothesized that individuals who experienced high congruence of work values would experience higher levels of internal work motivation than individuals who had low congruence of work values. It was also hypothesized that individuals who had an internal locus of control would experience more internal work motivation individuals well, the and have higher congruence of work values than who had an external locus of control. As possibility of locus of control as a moderator between importance of work values and internal work motivation was explored. Survey data were collected from 184 managerial level employees of the XYZ company during an ongoing training session. The following instruments were employed to measure the variables: Elizur's (1984) Importance of Work Values, Hunt and Saul's (1985) Achievement of Work Values, Hatfield, Robinson and Huseman's (1975) Job Perception Scale, a modified version of Rotter's (1966) I-E Locus of Control Scale and the Internal Work Motivation Scale (Hackman & Oldham, 1980) which is a part of the Job Diagnostic Survey. The findings indicated that locus of control was not a significant factor in determining congruence between work values or internal work motivation for this sample. Furthermore, locus of control was also found not to be a moderator between the importance of work values and internal work motivation. All individuals in this study had relatively high levels of internal work motivation. However, individuals who had higher congruence of work values did have significantly higher internal work motivation than those who had low congruence of work values for a majority of the 21 values. This was particularly true for the intrinsic values which included responsibility, meaningfulness and use of abilities. In addition, the data were analysed into a hierarchy of needs to indicate possible organizational development or human resource development needs for the XYZ corporation.
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Self-presentation reflects the processes by which individuals attempt to monitor and control the impressions others form of them (Schlenker & Leary, 1982). Concerns over impressions conveyed have been linked to numerous health behaviors (Crawford & Eklund, 1994; Martin, Leary, & O'Brien, 2001). The present study investigated the role of cognitive manifestations of dispositional and situational self presentational motivation (SPM) in 131 females with known groups differences on a measure of eating disorders. Participants were classified as in-treatment (IN = 39); at risk (AT = 46); and not at risk (NOT = 46) for eating disordered behaviour. Each participant completed The Brief Fear of Negative Evaluation Scale (FNE; Leary, 1983), the Public Self-Consciousness Scale (PSC; Fenigstein, Sheier, & Buss, 1975), and the Social Physique Anxiety Scale (SPA; Hart, Leary, & Rejeski, 1989), as measures of dispositional SPM. Situational SPM was assessed through Self-Presentational Efficacy (SPE; Gammage, Hall, & Martin, 2004), and the Exercise Motivation Inventory-2 (Markland & Ingeldew, 1997). Significant differences emerged on the measure of eating disorder behaviour between AT and NOT. To determine if group differences existed on measures of trait SPM an ANOVA was conducted. Results indicated that the NOT group experienced less FNE, PSC and SPA than the IN and AT groups, and the AT group experienced less FNE and PSC than the IN group. Pearson bivariate correlations were conducted on measures of trait SPM and EMI-2 subscales theoretically linked to SPM. It was found that FNE, PSC and SPA were all positively correlated with weight management for the NOT group. To determine if group differences existed on selfpresentational exercise motives independent samples I-tests were conducted. Results revealed that the AT group was more motivated to exercise for weight management, and appearance, and social recognition than the NOT group. To determine if group differences existed on the state measure of self-presentational efficacy a series of ANOVA's were conducted. Results revealed that the NOT group experienced significantly greater self-presentational efficacy expectancy and self-presentational outcome value than the AT group. Finally, a discriminant function analysis was conducted to determine if trait SPM would predict group membership. Results revealed that 63.4% of participants were correctly classified, with SPA, PSC, and FNE differentiating the NOT group from the AT and IN groups and FNE and PSC differentiating the AT group from the IN group. Thus self-presentation motivation appears to have an influence on females who have an eating disorder and those at risk for an eating disorder. Potential applications of the influence of self-presentational motives on eating disorders and future research directions are discussed.