Computer analysis of large civil engineering structures

The finite element method is now well established among engineers as being an extremely useful tool in the analysis of problems with complicated boundary conditions. One aim of this thesis has been to produce a set of computer algorithms capable of efficiently analysing complex three dimensional structures. This set of algorithms has been designed to permit much versatility. Provisions such as the use of only those parts of the system which are relevant to a given analysis and the facility to extend the system by the addition of new elements are incorporate. Five element types have been programmed, these are, prismatic members, rectangular plates, triangular plates and curved plates. The 'in and out of plane' stiffness matrices for a curved plate element are derived using the finite element technique. The performance of this type of element is compared with two other theoretical solutions as well as with a set of independent experimental observations. Additional experimental work was then carried out by the author to further evaluate the acceptability of this element. Finally the analysis of two large civil engineering structures, the shell of an electrical precipitator and a concrete bridge, are presented to investigate the performance of the algorithms. Comparisons are made between the computer time, core store requirements and the accuracy of the analysis, for the proposed system and those of another program.

How well do the theory of reasoned action and theory of planned behaviour predict intentions and attendance at screening programmes? A meta-analysis

Meta-analysis was used to quantify how well the Theories of Reasoned Action and Planned Behaviour have predicted intentions to attend screening programmes and actual attendance behaviour. Systematic literature searches identified 33 studies that were included in the review. Across the studies as a whole, attitudes had a large-sized relationship with intention, while subjective norms and perceived behavioural control (PBC) possessed medium-sized relationships with intention. Intention had a medium-sized relationship with attendance, whereas the PBC-attendance relationship was small sized. Due to heterogeneity in results between studies, moderator analyses were conducted. The moderator variables were (a) type of screening test, (b) location of recruitment, (c) screening cost and (d) invitation to screen. All moderators affected theory of planned behaviour relationships. Suggestions for future research emerging from these results include targeting attitudes to promote intention to screen, a greater use of implementation intentions in screening information and examining the credibility of different screening providers.

Using the theory of planned behaviour to understand binge drinking:the importance of beliefs for developing interventions

Objectives. To elicit students' salient beliefs in relation to binge drinking, and to examine the extent to which individual salient beliefs predict theory of planned behaviour (TPB) constructs in relation to binge drink, and actual drinking behaviour assessed later that evening. Design. Longitudinal, over a single evening. Methods. 192 students were recruited as they entered a campus bar at the beginning of the evening. They completed questionnaires with open-ended questions eliciting beliefs concerning binge drinking, and ratings scales assessing standard TPB constructs in relation to binge drinking. At the end of the evening, 181 completed a second questionnaire and recorded the number of alcoholic drinks they had consumed. Results. Beliefs were reliably coded (all kappas =0.79). Students with higher intentions to binge drink were more likely to believe that their friends approved of binge drinking, and that (lack of) money would make it difficult. Students who reported drinking more alcohol at the end of the evening were more likely to believe that getting drunk is an advantage/what they would like about binge drinking tonight, that their sports teams would approve, and that celebrating, drinking patterns, and environment would make it easy to binge drink. Conclusions. The present study has identified the individually salient beliefs relating to drinking behaviour that the TPB states should be addressed by interventions to alter behaviour, and which that should be assessed as mediators in intervention research. As a whole, these findings highlight the importance of perceived peer norms in binge drinking in this population, and support the idea of interventions to challenge the perception of social pressure to binge drink. ©2011 The British Psychological Society.

Speaking out of turn? Taking the initiative in teacher-fronted classroom interaction.

Teacher-fronted interaction is generally seen to place limitations on the contributions that learners can make to classroom discourse and the conclusion is that learners are unable to experiment with, for example, turn-taking mechanisms. This article looks at teacher-fronted interaction in the language classroom from the perspective of learner talk by examining how learners might take the initiative during this apparently more rigid form of interaction. Detailed microanalysis of classroom episodes, using a conversation analysis institutional discourse approach, shows how learners orient to the institutional context to make sophisticated and effective use of turn-taking mechanisms to take the initiative and direct the interaction, even in the controlled environment of teacher-fronted talk. The article describes some of the functions of such learner initiative, examines how learners and teachers co-construct interaction and how learners can create learning opportunities for themselves. It also briefly looks at teacher reactions to such initiative. The article concludes that learner initiative in teacher-fronted interaction may constitute a significant opportunity for learning and that teachers should find ways of encouraging such interaction patterns.

An exploration of predatory behaviour in cyberspace:towards a typology of cyberstalkers

Over the last few years governments, law enforcement agencies, and the media have noted increases of online harassment. Although there has been a great deal of research into 'offline stalking', at this moment in time there has been no formal research that attempts to classify cyberstalkers. This study aimed to identify a classification of cyberstalkers by interviewing victims. Twenty-four participants were interviewed and their responses logged on a 76-item Cyberstalking Incident Checklist. A typology of cyberstalkers was developed.

The study and measurements of the behaviour and characteristics of electromagnetic relays

The thesis presents a theoretical and practical study of the dynamic behaviour of electromagnetic relays. After discussing the problem of solving the dynamicc equations analytically and presenting a historical survey of the earlier works in the relay and its dynamics, the simulation of a relay on the analogue computer is discussed. It is shown that the simulation may be used to obtain specific solutions to the dynamic equations. The computer analysis provides the dynamic characteristics for design purposes and may be used in the study of bouncing, rebound oscillations and stability of the armature motion. An approximate analytical solution to the two dynamic equations is given based on the assumption that the dynamic variation of the pull with the position of the armature is linear. The assumption is supported by the Computer-aided analysis and experimental results. The solution is intended to provide a basis for a rational design. A rigorous method of analysing the dynamic performance by using Ahlberg's theory is also presented. This method may be justified to be the extension of Ahlberg's theory by taking the mass and frictional damping forces into account. While calculating the armature motion mathematically, Ahlberg considers the equilibrium of two kinds of forces, namely pull and load, and disregards the mass and friction forces, whereas the present method deals with the equilibrium of all four kinds of forces. It is shown how this can be utilised to calculate the dynamic characteristics for a specific design. The utility of this method also extends to the study of stability, contact bounce and armature rebound. The magnetic circuit and other related topics which are essential to the study of relay dynamics are discussed and some necessary experimental results are given.

Response to out of stock produce and its underlying economic considerations

The goal of this research is to investigate consumer response to out-of-stock product in the produce category. We do this by comparing results from a survey conducted in Greece and the United States to previous research on consumer response to out-of-stock situations for other perishable and non-perishable products. We further examined the underlying economic reasoning as well as the cultural and physical differences between the United States and Greece as explanations of different reactions. Out of Stock produce response proved different in produce than in other perishables and non-perishables. There is some evidence that produce does follow previous the suggested economic reasoning from the previous research, especially within transaction costs. Finally, the respondent’s country proved very significant in dictating response.

A study of the behaviour of the single phase induction type energy meter and the design of an instrumentation system for its calibration

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What do people think about when they answer theory of planned behaviour questionnaires? A 'think aloud' study

Two studies aiming to identify the nature and extent of problems that people have when completing theory of planned behaviour (TPB) questionnaires, using a cognitive interviewing approach are reported. Both studies required participants to 'think aloud' as they completed TPB questionnaires about: (a) increasing physical activity (six general public participants); and (b) binge drinking (13 students). Most people had no identifiable problems with the majority of questions. However, there were problems common to both studies, relating to information retrieval and to participants answering different questions from those intended by researchers. Questions about normative influence were particularly problematic. The standard procedure for developing TPB questionnaires may systematically produce problematic questions. Suggestions are made for improving this procedure. Copyright © 2007 SAGE Publications.

Moderation of cognition-intention and cognition-behaviour relations:a meta-analysis of properties of variables from the theory of planned behaviour

Meta-analysis was used to quantify the moderating effects of seven properties of cognitions-accessibility, temporal stability, direct experience, involvement, certainty, ambivalence and affective-cognitive consistency-on cognition-intention and cognition-behaviour relations. Literature searches revealed 44 studies that could be included in the review. Findings showed that all of the properties, except involvement, moderated attitude-behaviour consistency. Similarly, all relevant moderators improved the consistency between intentions and behaviour. Temporal stability moderated PBC-behaviour relations, certainty moderated subjective norm-intention relations, and ambivalence, certainty, and involvement all moderated attitude-intention relations. Overall, temporal stability appeared to be the strongest moderator of cognition-behaviour relations.

How well does the theory of planned behaviour predict alcohol consumption? A systematic review and meta-analysis

This study aimed to quantify correlations between theory of planned behaviour (TPB) variables and (i) intentions to consume alcohol and (ii) alcohol consumption. Systematic literature searches identified 40 eligible studies that were meta-analysed. Three moderator analyses were conducted: pattern of consumption, gender of participants and age of participants. Across studies, intentions had the strongest relationship with attitudes (r+ = .62), followed by subjective norms (r+ = .47) and perceived behavioural control (PBC; r+ = .31). Self-efficacy (SE) had a stronger relationship with intentions (r+ = .48) compared with perceived control (PC; r+ = −.10). Intention had the strongest relationship with alcohol consumption (r+ = .54), followed by SE (r+ = .41). In contrast, PBC and PC had negative relationships with alcohol consumption (r+ = −.05 and −.13, respectively). All moderators affected TPB relationships. Patterns of consumption with clear definitions had stronger TPB relations, females reported stronger attitude–intention relations than males, and adults reported stronger attitude–intention and SE–intention relations than adolescents. Recommendations for future research include targeting attitudes and intentions in interventions to reduce alcohol consumption, using clear definitions of alcohol consumption in TPB items to improve prediction and assessing SE when investigating risk behaviours.

Disseminating a warning message to evacuate:a simulation study of the behaviour of neighbours

Large-scale evacuations are a recurring theme on news channels, whether in response to major natural or manmade disasters. The role of warning dissemination is a key part in the success of such large-scale evacuations and its inadequacy in certain cases has been a 'primary contribution to deaths and injuries' (Hayden et al.; 2007). Along with technology-driven 'official warning channels' (e.g. sirens, mass media), the role of unofficial channel (e.g. neighbours, personal contacts, volunteer wardens) has proven to be significant in warning the public of the need to evacuate. Although post-evacuation studies identify the behaviours of evacuees as disseminators of the warning message, there has not been a detailed study that quantifies the effects of such behaviour on the warning message dissemination. This paper develops an Agent-Based Simulation (ABS) model of multiple agents (evacuee households) in a hypothetical community to investigate the impact of behaviour as an unofficial channel on the overall warning dissemination. Parameters studied include the percentage of people who warn their neighbours, the efficiency of different official warning channels, and delay time to warn neighbours. Even with a low proportion of people willing to warn their neighbour, the results showed considerable impact on the overall warning dissemination. © 2012 Elsevier B.V. All rights reserved.

Taking the carbon out of the car

Effective measures are being taken to reduce emissions from cars, which are now emerging as a major contributor to climate change. Developed countries will need to reduce emissions by at least 80% by 2050 to achieve stabilization of atmospheric CO2 concentration between 450 and 550 ppm, and have a unique opportunity to avoid the most damaging effects of climate change. The UK is aiming at completely decarbonising transport by 2050 through a combination of more efficient vehicles, cleaner fuels, and smart driving choices. The European Commission has proposed a mandatory CO2 target on new car CO 2 efficiency, which is an urgent needed development. The nation is also using regulatory targets for local schemes, such as free parking or congestion charging, break points for company car tax, and vehicle excise duty. Car ownership and use should thereby continue to drive economic growth and enhance quality of life around the world without destroying the planet.

Study of Queueing Behaviour in IP Buffers

It is unquestioned that the importance of IP network will further increase and that it will serve as a platform for more and more services, requiring different types and degrees of service quality. Modern architectures and protocols are being standardized, which aims at guaranteeing the quality of service delivered to users. In this paper, we investigate the queueing behaviour found in IP output buffers. This queueing increases because multiple streams of packets with different length are being multiplexed together. We develop balance equations for the state of the system, from which we derive packet loss and delay results. To analyze these types of behaviour, we study the discrete-time version of the “classical” queue model M/M/1/k called Geo/Gx/1/k, where Gx denotes a different packet length distribution defined on a range between a minimum and maximum value.