33 resultados para Catastrophic Cognitions

em Aston University Research Archive


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In this research, conceptualizations of the links between technological innovation and organizational change are explored and recommendations in the literature concerning such changes are reviewed and criticized. Such recommendations do not usually address the details of social interactions by which organizational changes take place. As a consequence, the issue of how these recommendations become relevant for the actors who would carry them out is not addressed. The complexity of organizational change processes highlights the role of actors' interpretations of organizational reality. Interpretations take place through the use of language in the interaction between actors. Theoretical contributions and recommendations concerning organizational changes should be seen therefore as discourses which contribute to these interpretations. They will influence the process of change only if they become relevant for organizational actors'. A method for analysing discourse in organizations is presented. It is used to identify the variety of discourses which are put forward in organizations, and to describe the structure of their distribution among actors. The structures of discourses in three companies suggest that knowledge about technological innovation processes becomes relevant to the extent that it contributes to political/discursive processes maintained by actors attempting to secure or change their role definitions. It follows that recommendations concerning planned organizational change should take into account these processes explicitly. It is therefore suggested that the analysis of discourse can be a valuable instrument for monitoring change processes. Suggestions for further research are made, concerning (i) the development of the method itself and its use in real situations (ii) the study of how discourse structures evolve over time and episodes of change.

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Based on the attributional reformulation of learned helplessness theory (Abramson, Seligman, & Teasdale, 1978) and Lazarus and Launier's (1978) primary-secondary appraisal theory of stress, the present study sought to examine teleworkers' reactions to their work-related problems. The role of attributions about the sources, and cognitions about the consesquences, of these problems in promoting positive adaptation was addressed. In particular, it was predicted that teleworkers who made optimistic attributions and cognitions would be more likely to employ problem-focused coping strategies and, as a result, report more positive psychological and job-related outcomes. Based on a survey sample of 192 teleworkers, the results indicated that a tendency to engage in self-blame was related to the use of emotion-focused coping strategies. In turn, there was evidence linking emotion-focused coping strategies to negative outcomes and problem-focused coping strategies to positive outcomes. The results are discussed in relation to attributional approaches to stress which highlight the importance of cognitions about the consequences of negative events. Finally, implications for the training of teleworkers are presented.

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Objective: The current study examined the contribution of prenatal and postnatal maternal core beliefs, self-esteem, psychopathologic symptoms, and postnatal infant temperament to the prediction of infant feeding difficulties. Method: Ninety-nine women completed questionnaires assessing their core beliefs, psychopathology, and self-esteem during pregnancy and at 6 months postpartum. At 6 months, mothers also rated their infant's temperament and feeding, and were observed feeding their infants. Results: Maternal reports of child feeding difficulties were predicted by higher levels of emotional deprivation and entitlement core beliefs and lower levels of self-sacrifice and enmeshment core beliefs during pregnancy. Postnatal social isolation core beliefs, lower maternal self-esteem, and more difficult infant temperament added significantly to the variance explained by prenatal factors. Maternal core beliefs, self-esteem, psychopathology, and infant temperament failed to significantly predict independent observations of child food refusal. Conclusion: Maternal cognitions are implicated in the development of maternal reports of feeding difficulty.

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DUE TO INCOMPLETE PAPERWORK, ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT

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Jackson (2005) developed a hybrid model of personality and learning, known as the learning styles profiler (LSP) which was designed to span biological, socio-cognitive, and experiential research foci of personality and learning research. The hybrid model argues that functional and dysfunctional learning outcomes can be best understood in terms of how cognitions and experiences control, discipline, and re-express the biologically based scale of sensation-seeking. In two studies with part-time workers undertaking tertiary education (N=137 and 58), established models of approach and avoidance from each of the three different research foci were compared with Jackson's hybrid model in their predictiveness of leadership, work, and university outcomes using self-report and supervisor ratings. Results showed that the hybrid model was generally optimal and, as hypothesized, that goal orientation was a mediator of sensation-seeking on outcomes (work performance, university performance, leader behaviours, and counterproductive work behaviour). Our studies suggest that the hybrid model has considerable promise as a predictor of work and educational outcomes as well as dysfunctional outcomes.

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Problem: The vast majority of research examining the interplay between aggressive emotions, beliefs, behaviors, cognitions, and situational contingencies in competitive athletes has focused on Western populations and only select sports (e.g., ice hockey). Research involving Eastern, particularly Chinese, athletes is surprisingly sparse given the sheer size of these populations. Thus, this study examines the aggressive emotions, beliefs, behaviors, and cognitions, of competitive Chinese athletes. Method: Several measures related to aggression were distributed to a large sample (N ¼ 471) of male athletes, representing four sports (basketball, rugby union, association football/soccer, and squash). Results: Higher levels of anger and aggression tended to be associated with higher levels of play for rugby and low levels of play for contact (e.g., football, basketball) and individual sports (e.g., squash). Conclusions: The results suggest that the experience of angry emotions and aggressive behaviors of Chinese athletes are similar to Western populations, but that sport psychology practitioners should be aware of some potentially important differences, such as the general tendency of Chinese athletes to disapprove of aggressive behavior.

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Throughout the 1970s and 1980s, West Germany was considered to be one of the world’s most successful economic and political systems. In his seminal 1987 analysis of West Germany’s ‘semisovereign’ system of governance, Peter Katzenstein attributed this success to a combination of a fragmented polity, consensus politics and incremental policy changes. However, unification in 1990 has both changed Germany’s institutional configuration and created economic and social challenges on a huge scale. This volume therefore asks whether semisovereignty still exists in contemporary Germany and, crucially, whether it remains an asset in terms of addressing these challenges. By shadowing and building on the original study, an eminent team of British, German and American scholars analyses institutional changes and the resulting policy developments in key sectors, with Peter Katzenstein himself providing the conclusion. Together, the chapters provide a landmark assessment of the outcomes produced by one of the world’s most important countries. Contents: 1. Introduction: semisovereignty challenged Simon Green and William E. Paterson; 2. Institutional transfer: can semisovereignty be transferred? The political economy of Eastern Germany Wade Jacoby; 3. Political parties Thomas Saalfeld; 4. Federalism: the new territorialism Charlie Jeffery; 5. Shock-absorbers under stress. Parapublic institutions and the double challenges of German unification and European integration Andreas Busch; 6. Economic policy management: catastrophic equilibrium, tipping points and crisis interventions Kenneth Dyson; 7. Industrial relations: from state weakness as strength to state weakness as weakness. Welfare corporatism and the private use of the public interest Wolfgang Streeck; 8. Social policy: crisis and transformation Roland Czada; 9. Immigration and integration policy: between incrementalism and non-decisions Simon Green; 10. Environmental policy: the law of diminishing returns? Charles Lees; 11. Administrative reform Kluas H. Goetz; 12. European policy-making: between associated sovereignty and semisovereignty William E. Paterson; 13. Conclusion: semisovereignty in United Germany Peter J. Katzenstein.

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We propose a simple model that captures the salient properties of distribution networks, and study the possible occurrence of blackouts, i.e., sudden failings of large portions of such networks. The model is defined on a random graph of finite connectivity. The nodes of the graph represent hubs of the network, while the edges of the graph represent the links of the distribution network. Both, the nodes and the edges carry dynamical two state variables representing the functioning or dysfunctional state of the node or link in question. We describe a dynamical process in which the breakdown of a link or node is triggered when the level of maintenance it receives falls below a given threshold. This form of dynamics can lead to situations of catastrophic breakdown, if levels of maintenance are themselves dependent on the functioning of the net, once maintenance levels locally fall below a critical threshold due to fluctuations. We formulate conditions under which such systems can be analyzed in terms of thermodynamic equilibrium techniques, and under these conditions derive a phase diagram characterizing the collective behavior of the system, given its model parameters. The phase diagram is confirmed qualitatively and quantitatively by simulations on explicit realizations of the graph, thus confirming the validity of our approach. © 2007 The American Physical Society.

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Isocyanate cross-linked hydroxy terminated polybutadiene is used as a binder for solid rocket propellant. Rocket motors containing this propellant require a storage life of at least 20 years. During storage it has been found that the important rubbery properties of the binder can be lost due to oxidative cross-linking of the polybutadiene chains. This could cause catastrophic failure when the rocket motor is required. At present the bis-hindered phenol Calco 2246 is used as a thermal oxidative stabiliser, but it's performance is only adequate. This has led to the search for a more efficient stabiliser system. To hasten the evaluation of new antioxidant systems the use of dynamic thermal analysis was investigated. Results showed that a tentative relationship existed between predictions by thermal analysis and the long term oven ageing for simple single antioxidant systems. But for more complex systems containing either autosynergistic or mixed antioxidants no relationship was observed suggesting that results for such an "accelerated" technique cannot be used for the purpose of extrapolation for long term performance. This was attributed to the short time and more aggressive condition used (hjgher temperature and oxygen rich atmosphere in thermal analysis) altering the mechanism of action of the antioxidants and not allowing time for co-operative effect of the combined antioxidant system to form. One potential problem for the binder system is the use of an diisocyanate as a cross-linking agent. This reacts with the hydroxyl hydrogen on the polymer as well as other active hydrogens such as those contained in a number of antioxidants, affecting both cross-linking and antioxidant effectiveness. Studies in this work showed that only antioxidants containing amine moieties have a significant affect on binder preparation, with the phenolic antioxidants not reacting. This is due to the greater nucleophilicity of the amines. Investigation of a range of antioxidant systems, including potentially homo, hetero and autosynergistic systems, has highlighted a number of systems which show considerably greater effectiveness than the currently used antioxidant Calco 2246. The only single antioxidant which showed improvement was the partially unhindered phenol y-Tocopherol. Of the mixed systems combinations of the sulphur containing antioxidants e.g. DLTP with higher levels of chain-breaking antioxidants, especially Calco 2246, were the most promising. Also the homosynergistic mix of an aromatic amine and a phenol was seen to be very effective but the results were inconsistent. This inconsistency could be explained by the method of sample preparation used. It was shown that the efficiency of a number of antioxidant.s could be dramatically improved by the use of ultrasound during the mixing stage of preparation. The reason for this increase in performance is unclear but in the case of the homosynergistic amine/phenol mix both more efficient mixing and/or the production of a novel mechanism of action are suggested

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Deep hole drilling is one of the most complicated metal cutting processes and one of the most difficult to perform on CNC machine-tools or machining centres under conditions of limited manpower or unmanned operation. This research work investigates aspects of the deep hole drilling process with small diameter twist drills and presents a prototype system for real time process monitoring and adaptive control; two main research objectives are fulfilled in particular : First objective is the experimental investigation of the mechanics of the deep hole drilling process, using twist drills without internal coolant supply, in the range of diarneters Ø 2.4 to Ø4.5 mm and working length up to 40 diameters. The definition of the problems associated with the low strength of these tools and the study of mechanisms of catastrophic failure which manifest themselves well before and along with the classic mechanism of tool wear. The relationships between drilling thrust and torque with the depth of penetration and the various machining conditions are also investigated and the experimental evidence suggests that the process is inherently unstable at depths beyond a few diameters. Second objective is the design and implementation of a system for intelligent CNC deep hole drilling, the main task of which is to ensure integrity of the process and the safety of the tool and the workpiece. This task is achieved by means of interfacing the CNC system of the machine tool to an external computer which performs the following functions: On-line monitoring of the drilling thrust and torque, adaptive control of feed rate, spindle speed and tool penetration (Z-axis), indirect monitoring of tool wear by pattern recognition of variations of the drilling thrust with cumulative cutting time and drilled depth, operation as a data base for tools and workpieces and finally issuing of alarms and diagnostic messages.

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The thesis deals with a research programme in which the cutting performance of a new generation of ceramic cutting tool material is evaluated using the turning process. In part one, the performance of commercial Kyon 2000 sialon ceramic inserts is studied when machining a hardened alloy steel under a wide range of cutting conditions. The aim is to formulate a pattern of machining behaviour in which tool wear is related to a theoretical interpretation of the temperatures and stresses generated by the chip-tool interaction. The work involves a correlation of wear measurement and metallographic examination of the wear area with the measurable cutting data. Four main tool failure modes are recognised: (a) flank and crater wear (b) grooving wear (c) deformation wear and (d) brittle failure Results indicate catastrophic edge breakdown under certain conditions. Accordingly in part two, the edge geometry is modified to give a double rake tool; a negative/positive combination. The results are reported for a range of workpiece materials under orthogonal cutting conditions. Significant improvements in the cutting performance are achieved. The improvements are explained by a study of process parameters; cutting forces, chip thickness ratio, chip contact length, temperature distribution, stress distribution and chip formation. In part three, improvements in tool performance are shown to arise when the edge chamfer on a single rake tool is modified. Under optimum edge chamfer conditions a substantial increase in tool life is obtained compared with the commercial cutting geometry.

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The occurrence of spalling is a major factor in determining the fire resistance of concrete constructions. The apparently random occurrence of spalling has limited the development and application of fire resistance modelling for concrete structures. This Thesis describes an experimental investigation into the spalling of concrete on exposure to elevated temperatures. It has been shown that spalling may be categorised into four distinct types, aggregate spalling, corner spalling, surface spalling and explosive spalling. Aggregate spalling has been found to be a form of shear failure of aggregates local to the heated surface. The susceptibility of any particular concrete to aggregate spalling can be quantified from parameters which include the coefficients of thermal expansion of both the aggregate and the surrounding mortar, the size and thermal diffusivity of the aggregate and the rate of heating. Corner spalling, which is particularly significant for the fire resistance of concrete columns, is a result of concrete losing its tensile strength at elevated temperatures. Surface spalling is the result of excessive pore pressures within heated concrete. An empirical model has been developed to allow quantification of the pore pressures and a material failure model proposed. The dominant parameters are rate of heating, pore saturation and concrete permeability. Surface spalling may be alleviated by limiting pore pressure development and a number of methods to this end have been evaluated. Explosive spalling involves the catastrophic failure of a concrete element and may be caused by either of two distinct mechanisms. In the first instance, excessive pore pressures can cause explosive spalling, although the effect is limited principally to unloaded or relatively small specimens. A second cause of explosive spalling is where the superimposition of thermally induced stresses on applied load stresses exceed the concrete's strength.

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Aims: This study tested the impact of combining a motivational intervention based on protection motivation theory (PMT, Rogers, 1983 [18]) plus a volitional intervention based on action planning and coping planning, as a way to promote the prevention of type 2 diabetes among UK undergraduates. Methods: Eighty-four participants were randomly assigned to either a control group or one of three experimental conditions: motivational intervention (PMT), volitional intervention (APCP), or combined motivational and volitional intervention (PMT&APCP). PMT variables, dietary and exercise behaviours were measured at three time-points over a four-week period. Results: The motivational intervention significantly changed PMT variables. The combined motivational and volitional intervention significantly decreased fat intake and increased the frequency of exercise relative to all other groups, and significantly increased the amount of fruit and vegetables consumed relative to control and volitional intervention groups. Conclusions: These results suggest that motivational intervention is effective at changing cognitions but changing behaviour requires an intervention based on both motivation and volition.