Plastic bending behaviour and section moment capacities of mono-symmetric LiteSteel Beams with web openings

Recently developed cold-formed LiteSteel beam (LSB) sections have found increasing popularity in residential, industrial and commercial buildings due to their light weight and cost-effectiveness. Currently, there is significant interest in the use of LSB sections as flexural members in floor joist systems, although they can be used as flexural and compression members in a range of building systems. The plastic bending behaviour and section moment capacity of LSB sections with web holes can be assumed to differ from those without, but have yet to be investigated. Hence, no appropriate design rules for determining the section moment capacity of LSB sections with web holes are yet available. This paper presents the results of an investigation of the plastic bending behaviour and section moment capacity of LSB sections with circular web holes. LSB sections with varying circular hole diameters and degrees of spacing were considered. The paper also describes the simplified finite element (FE) modelling technique employed in this study, which incorporates all of the significant behavioural effects that influence the plastic bending behaviour and section moment capacity of these sections. The numerical and experimental test results and associated findings are also presented.

Behaviour and design of cold-formed steel beams subject to lateral-torsional buckling

Cold-formed steel beams are increasingly used as floor joists and bearers in buildings. Their behaviour and moment capacities are influenced by lateral-torsional buckling when they are not laterally restrained adequately. Past research on lateral-torsional buckling has concentrated on hot-rolled steel beams. Hence a numerical study was undertaken to investigate the lateral-torsional buckling behaviour of simply supported cold-formed steel lipped channel beams subjected to uniform bending. For this purpose a finite element model was developed using ABAQUS and its accuracy was verified using available numerical and experimental results. It was then used in a detailed parametric study to simulate the lateral-torsional buckling behaviour and capacity of cold-formed steel beams under varying conditions. The moment capacity results were compared with the predictions from the current design rules in many cold-formed steel codes and suitable recommendations were made. European design rules were found to be conservative while Australian/New Zealand and North American design rules were unconservative. Hence the moment capacity design equations in these codes were modified in this paper based on the available finite element analysis results. This paper presents the details of the parametric study, recommendations to current design rules and the new design rules proposed in this research for lateral-torsional buckling of cold-formed steel lipped channel beams.

Lateral torsional buckling behaviour of cold-formed steel beams at elevated temperatures

Abstract: This paper presents the details of a study into the behaviour and moment capacities of cold-formed steel lipped channel beams (LCB) subject to lateral-torsional buckling at elevated temperatures. It was based on a validated numerical model of a simply supported and laterally unrestrained LCB subjected to a uniform moment. The ultimate moment capacities from this study were compared with the predicted values using ambient and fire design methods. This study showed that the lateral torsional buckling capacity is strongly influenced by the level of non-linearity in the stress-strain curves of steel at elevated temperatures. Hence most of the current design methods based on a single buckling curve were not adequate to determine the moment capacities. This paper proposes a new design method for the cold-formed steel LCBs subject lateral-torsional buckling at elevated temperatures.

Investigation into the transport, behaviour and deposition of combustion aerosols from transport sources

The deterioration of air quality is a significant issue in large and growing cities. This work investigates particulate emissions from transport, the largest source of air pollution in cities today. Emitters such as busy roads and diesel trains are investigated, with specific reference to the evolution of particles over time and distance. Diesel trains are investigated as an alternative to road traffic in investigating evolutionary processes. Higher emissions and solitary sources mean that the emitted plume can be observed over time in a single location. These results represent the first investigation of the evolution of fine and ultrafine aerosol particles from this type of source. Aerosols near a busy road are investigated, with the result that a dependence of total number concentration on distance from the road is shown to be related to the fragmentation of nanoparticle clusters. Local meteorological conditions are also monitored and humidity is shown to vary with distance from the road in a nonmonotonic way. Particles from a busy road were also examined using a scanning electron microscope, with the intention of understanding the make up of the emitted aerosol plume. It was determined that due to significant surface behaviour post-deposition, this method of analysis could not directly classify airborne pollutants. Some interesting results were obtained however, particularly in terms of composite particles and the analysis of deposited patterns. This thesis introduces new work in terms of the analysis of diesel train particulate emissions, as well as adding further evidence towards the fragmentation process of aerosol evolution in both background concentrations and emitted aerosol plumes.

Acceptability of cognitive-behaviour therapy via the Internet for cessation of benzodiazepine use

Introduction and Aims: Long-term use of benzodiazepines remains common, and conveys significant risk. Providing psychological intervention in association with gradual dose reduction increases cessation rates above dose reduction alone, but appropriate psychological support is difficult to obtain. This study was undertaken to assess the outcomes of an uncontrolled case series of an internet-based cognitive-behaviour therapy (I-CBT) for benzodiazepine cessation. Design and Method: Users of benzodiazepines for > 3 months who wanted to reduce or cease benzodiazepines participated in the trial. They completed online assessments and accessed 13 newsletters on managing withdrawal symptoms and developing alternate ways to cope with life events. Therapist assistance was provided by email. Follow-up was at 3 and 6 months and feedback was obtained via comments and emails. Results: Program ratings and emailed comments of the program were positive. Thirty-two people registered for the program and 14 (44%) completed a 6-month follow-up. Of these, 8 (57%) reduced weekly intake by at least half, including 5 (36%) who ceased use. Shorter duration of use and birth outside Australia predicted greater percentage reductions at 3 months, while being partnered and in paid employment predicted reductions at 6 months. Discussion and Conclusion: While results were encouraging, controlled research is required to confirm the efficacy of the program, and engagement of both users and prescribers needs further attention.

Ethical issues in research on adolescent depression and suicidal behaviour

Argues that the codes of ethical conduct of the Australian Psychological Society and the American Psychological Association imply that researchers of adolescent depression and suicidal behavior must plan to intervene to assess risk where a participant in a study indicates an intention to commit suicide. Participants in research of this kind need to be advised of this possibility in advance. The obligation to intervene, and to advise of the possibility of intervention, poses practical and methodological problems for research in this area but does not, it is argued, absolve the researcher of the primary responsibility to contribute to the welfare of the research participant. This obligation exists only when there is indication of harm but not, for instance, in the case of depression without suicidal intent.

Quantum-like non-separability of concept combinations, emergent associates and abduction

Consider the concept combination ‘pet human’. In word association experiments, human subjects produce the associate ‘slave’ in relation to this combination. The striking aspect of this associate is that it is not produced as an associate of ‘pet’, or ‘human’ in isolation. In other words, the associate ‘slave’ seems to be emergent. Such emergent associations sometimes have a creative character and cognitive science is largely silent about how we produce them. Departing from a dimensional model of human conceptual space, this article will explore concept combinations, and will argue that emergent associations are a result of abductive reasoning within conceptual space, that is, below the symbolic level of cognition. A tensor-based approach is used to model concept combinations allowing such combinations to be formalized as interacting quantum systems. Free association norm data is used to motivate the underlying basis of the conceptual space. It is shown by analogy how some concept combinations may behave like quantum-entangled (non-separable) particles. Two methods of analysis were presented for empirically validating the presence of non-separable concept combinations in human cognition. One method is based on quantum theory and another based on comparing a joint (true theoretic) probability distribution with another distribution based on a separability assumption using a chi-square goodness-of-fit test. Although these methods were inconclusive in relation to an empirical study of bi-ambiguous concept combinations, avenues for further refinement of these methods are identified.

Commentaries and Responses to "The Driver Behaviour Questionnaire as a predictor of accidents: A meta-analysis" [Commentaries lead by Anders af Wahlberg; Responses lead by J.C.F. de Winter]

The following discussion is in response to a 2010 article published in the Journal of Safety Research by J.C.F. de Winter and D. Dodou entitled “The Driver Behaviour Questionnaire as a predictor of accidents: A meta-analysis” (Volume 41, Number 6, pp. 463-470, available on sciencedirect.com). The editors are pleased to provide a forum for this exchange and welcome further comments.

Structural behaviour and design of cold-formed steel wall systems under fire conditions

In recent times, light gauge steel framed (LSF) structures, such as cold-formed steel wall systems, are increasingly used, but without a full understanding of their fire performance. Traditionally the fire resistance rating of these load-bearing LSF wall systems is based on approximate prescriptive methods developed based on limited fire tests. Very often they are limited to standard wall configurations used by the industry. Increased fire rating is provided simply by adding more plasterboards to these walls. This is not an acceptable situation as it not only inhibits innovation and structural and cost efficiencies but also casts doubt over the fire safety of these wall systems. Hence a detailed fire research study into the performance of LSF wall systems was undertaken using full scale fire tests and extensive numerical studies. A new composite wall panel developed at QUT was also considered in this study, where the insulation was used externally between the plasterboards on both sides of the steel wall frame instead of locating it in the cavity. Three full scale fire tests of LSF wall systems built using the new composite panel system were undertaken at a higher load ratio using a gas furnace designed to deliver heat in accordance with the standard time temperature curve in AS 1530.4 (SA, 2005). Fire tests included the measurements of load-deformation characteristics of LSF walls until failure as well as associated time-temperature measurements across the thickness and along the length of all the specimens. Tests of LSF walls under axial compression load have shown the improvement to their fire performance and fire resistance rating when the new composite panel was used. Hence this research recommends the use of the new composite panel system for cold-formed LSF walls. The numerical study was undertaken using a finite element program ABAQUS. The finite element analyses were conducted under both steady state and transient state conditions using the measured hot and cold flange temperature distributions from the fire tests. The elevated temperature reduction factors for mechanical properties were based on the equations proposed by Dolamune Kankanamge and Mahendran (2011). These finite element models were first validated by comparing their results with experimental test results from this study and Kolarkar (2010). The developed finite element models were able to predict the failure times within 5 minutes. The validated model was then used in a detailed numerical study into the strength of cold-formed thin-walled steel channels used in both the conventional and the new composite panel systems to increase the understanding of their behaviour under nonuniform elevated temperature conditions and to develop fire design rules. The measured time-temperature distributions obtained from the fire tests were used. Since the fire tests showed that the plasterboards provided sufficient lateral restraint until the failure of LSF wall panels, this assumption was also used in the analyses and was further validated by comparison with experimental results. Hence in this study of LSF wall studs, only the flexural buckling about the major axis and local buckling were considered. A new fire design method was proposed using AS/NZS 4600 (SA, 2005), NAS (AISI, 2007) and Eurocode 3 Part 1.3 (ECS, 2006). The importance of considering thermal bowing, magnified thermal bowing and neutral axis shift in the fire design was also investigated. A spread sheet based design tool was developed based on the above design codes to predict the failure load ratio versus time and temperature for varying LSF wall configurations including insulations. Idealised time-temperature profiles were developed based on the measured temperature values of the studs. This was used in a detailed numerical study to fully understand the structural behaviour of LSF wall panels. Appropriate equations were proposed to find the critical temperatures for different composite panels, varying in steel thickness, steel grade and screw spacing for any load ratio. Hence useful and simple design rules were proposed based on the current cold-formed steel structures and fire design standards, and their accuracy and advantages were discussed. The results were also used to validate the fire design rules developed based on AS/NZS 4600 (SA, 2005) and Eurocode Part 1.3 (ECS, 2006). This demonstrated the significant improvements to the design method when compared to the currently used prescriptive design methods for LSF wall systems under fire conditions. In summary, this research has developed comprehensive experimental and numerical thermal and structural performance data for both the conventional and the proposed new load bearing LSF wall systems under standard fire conditions. Finite element models were developed to predict the failure times of LSF walls accurately. Idealized hot flange temperature profiles were developed for non-insulated, cavity and externally insulated load bearing wall systems. Suitable fire design rules and spread sheet based design tools were developed based on the existing standards to predict the ultimate failure load, failure times and failure temperatures of LSF wall studs. Simplified equations were proposed to find the critical temperatures for varying wall panel configurations and load ratios. The results from this research are useful to both structural and fire engineers and researchers. Most importantly, this research has significantly improved the knowledge and understanding of cold-formed LSF loadbearing walls under standard fire conditions.

A Context Space Model for Detecting Anomalous Behaviour in Video Surveillance

Having a good automatic anomalous human behaviour detection is one of the goals of smart surveillance systems’ domain of research. The automatic detection addresses several human factor issues underlying the existing surveillance systems. To create such a detection system, contextual information needs to be considered. This is because context is required in order to correctly understand human behaviour. Unfortunately, the use of contextual information is still limited in the automatic anomalous human behaviour detection approaches. This paper proposes a context space model which has two benefits: (a) It provides guidelines for the system designers to select information which can be used to describe context; (b)It enables a system to distinguish between different contexts. A comparative analysis is conducted between a context-based system which employs the proposed context space model and a system which is implemented based on one of the existing approaches. The comparison is applied on a scenario constructed using video clips from CAVIAR dataset. The results show that the context-based system outperforms the other system. This is because the context space model allows the system to considering knowledge learned from the relevant context only.

The role of cultural beliefs in contributing to risky road use behaviour in Pakistan

Background Pakistan has the highest population rate of road fatalities in South Asia (25.3 fatalities per 100,000 people: Global Status Report on Road Safety, WHO 2009). Along with road environment and vehicle factors, human factors make a substantial contribution to traffic safety in Pakistan. Beliefs about road crash causation and prevention have been demonstrated to contribute to risky road use behaviour and resistance to preventive measures in a handful of other developing countries, but has not been explored in Pakistan. In particular, fatalism (whether based on religion, other cultural beliefs or experience) has been highlighted as a barrier to achieving changes in attitudes and behaviour. Aims The research reported here aimed (i) to explore perceptions of road crash causation among policy makers, police officers, professional drivers and car drivers in Pakistan; (ii) to identify how cultural and religious beliefs influence road use behaviour in Pakistan; and (iii) to understand how fatalistic beliefs may work as obstacles to road safety interventions. Methods In-depth interviews were conducted by the primary author (mostly in Urdu) in Lahore, Rawalpindi and Islamabad with 12 professional drivers (taxi, bus and truck), 4 car drivers, 6 police officers, 4 policy makers and 2 religious orators. All but two were Muslim, two were female, and they were drawn from a wide range of ages (24 to 60) and educational backgrounds. The interviews were taped and transcribed, then translated into English and analysed for themes related to the aims. Results Fatalism emerged as a pervasive belief utilised to justify risky road use behaviour and to resist messages about preventive measures. There was a strong religious underpinning to the statement of fatalistic beliefs (this reflects popular conceptions of Islam rather than scholarly interpretations), but also an overlap with superstitious beliefs which have longer-standing roots in Pakistani culture. These beliefs were not limited to people of poor educational background or position. A particular issue which was explored in more detail was the way in which these beliefs and their interpretation within Pakistani society contributed to poor police reporting of crashes. Discussion and conclusions The pervasive nature of fatalistic beliefs in Pakistan affects road user behaviour by supporting continued risk taking behaviour on the road, and by interfering with public health messages about behaviours which would reduce the risk of traffic crashes. The widespread influence of these beliefs on the ways that people respond to traffic crashes and the death of family members contribute to low crash reporting rates and to a system which is difficult to change. The promotion of an evidence-based approach to road user behaviour is recommended, along with improved professional education for police and policy makers.

Entertainment architecture : constructing a framework for the creation of an emerging transmedia form

This thesis investigates the radically uncertain formal, business, and industrial environment of current entertainment creators. It researches how a novel communication technology, the Internet, leads to novel entertainment forms, how these lead to novel kinds of businesses that lead to novel industries; and in what way established entertainment forms, businesses, and industries are part of that process. This last aspect is addressed by focusing on one exemplary es-tablished form: movies. Using a transdisciplinary approach and a combination of historical analysis, industry interviews, and an innovative mode of ‘immersive’ textual analysis, a coherent and comprehensive conceptual framework for the creation of and re-search into a specific emerging entertainment form is proposed. That form, products based on it, and the conceptual framework describing it are all re-ferred to as Entertainment Architecture (‘entarch,’ for short). The thesis charac-terises this novel form as Internet-native transmedia entertainment, meaning it fully utilises the unique communicative characteristics of the Internet, and is spread across media. The thesis isolates four constitutive elements within Entertainment Architec-ture: story, play, ‘dance,’ and ‘glue.’ That is, entarch tells a story; offers playful interaction; invites social interaction between producer and consumer, and amongst consumers (‘dance’); and all components of it can be spread across many media, but are so well interconnected and mutually dependent that they are perceived as one product instead of many (‘glue’). This sets entarch apart from current media franchises like Star Wars or Halo, which are perceived as many products spread across many media. Entarch thus embraces the commu-nicative behaviour of Internet-native consumers instead of forcing them to de-sist from it, it harnesses the strengths of various media while avoiding some of their weaknesses, and it can sustain viable businesses. The entarch framework is an innovative contribution to scholarship that al-lows researchers to investigate this emerging entertainment form in a structured way. The thesis demonstrates this by using it to survey business models appro-priate to the entarch environment. The framework can also be used by enter-tainment creators — exemplified in the thesis by moviemakers — to delimit the room for manoeuvre available to them in a changing environment.

A further exploration of sensation seeking propensity, reward sensitivity, depression, anxiety, and the risky behaviour of young novice drivers in a structural equation model

Young novice drivers constitute a major public health concern due to the number of crashes in which they are involved, and the resultant injuries and fatalities. Previous research suggests psychological traits (reward sensitivity, sensation seeking propensity), and psychological states (anxiety, depression) influence their risky behaviour. The relationships between gender, anxiety, depression, reward sensitivity, sensation seeking propensity and risky driving are explored. Participants (390 intermediate drivers, 17-25 years) completed two online surveys at a six month interval. Surveys comprised sociodemographics, Brief Sensation Seeking Scale, Kessler’s Psychological Distress Scale, an abridged Sensitivity to Reward Questionnaire, and risky driving behaviour was measured by the Behaviour of Young Novice Drivers Scale. Structural equation modelling revealed anxiety, reward sensitivity and sensation seeking propensity predicted risky driving. Gender was a moderator, with only reward sensitivity predicting risky driving for males. Future interventions which consider the role of rewards, sensation seeking, and mental health may contribute to improved road safety for younger and older road users alike.

Qualitative inquiry as transformation and agency : the black sheep and workplace mobbing

This chapter discusses an action research project into the lived experience of the workplace mobbing phenomenon. The action research methodology is based on the exemplarian model (Coenen & Khonraad, 2003) from the Netherlands Group. This model requires positive outcomes for those immersed in the problem to reduce the adversity of their circumstances. The findings challenge the psychological perspective of the existing bullying literature that tends to focus on individual behaviour. This research, undertaken over a three year period with 212 participants, identified the dysfunctional nature of public sector bureaucracies and the power gained through gossip and rumour as some of the key emergent themes to explain the workplace mobbing problem. In addition, resistance, conscientisation, and agency were identified as the key to transformation for those targeted. The discussion focuses on the crystallisation phase of the exemplarian model where the participants identified themselves as the Black Sheep and adopted the motto that “a black sheep is a biting beast” (Bastard, 1565 or 6-1618, p. 90), reflecting a sense of empowerment, individual agency, and a sense of humour in dealing with the serious yet seemingly absurd reality of their situations. The identity of the Black Sheep was consolidated when the group organised a 2 day conference with over 200 attendees to discuss how best to prevent workplace mobbing. This self-affirming action was a proactive step towards metaphorically “biting back” at the problem. A number of positive outcomes were achieved including the conference with over 200 attending leading to national media coverage across Australia and additional interviews with magazines, newspapers, and radio.

The power of malicious gossip

This paper focuses on malicious workplace gossip from the perspective of those targeted by this dark form of organisational communication. Findings from a large exemplarian action research project are reported that suggest malicious gossip can be an influential form of power that strongly contributes to counterproductive organisational behaviour. The discussion draws upon the emergent themes from the research to highlight the negative consequences of malicious gossip for those targeted and their organisations, and in so doing, elaborates on the phenomenon of workplace mobbing. This research highlights the importance of recognising gossip as an effective, though dark, form of power and the value of rational discourse for improving organisational communication.