Numerical study of impact forces on railway sleepers under wheel flat

Wheel-rail interaction is one of the most important research topics in railway engineering. It includes track vibration, track impact response and safety of the track. Track structure failures caused by impact forces can lead to significant economic loss for track owners through damage to rails and to the sleepers beneath. The wheel-rail impact forces occur because of imperfections on the wheels or rails such as wheel flats, irregular wheel profile, rail corrugation and differences in the height of rails connected at a welded joint. The vehicle speed and static wheel load are important factors of the track design, because they are related to the impact forces under wheel-rail defects. In this paper, a 3-Dimensional finite element model for the study of wheel flat impact is developed by use of the FEA software package ANSYS. The effects of the wheel flat to impact force on sleepers with various speeds and static wheel loads under a critical wheel flat size are investigated. It has found that both wheel-rail impact force and impact force on sleeper induced by wheel flat are varying nonlinearly by increasing the vehicle speed; both impact forces are nonlinearly and monotonically increasing by increasing the static wheel load. The relationships between both of impact forces induced by wheel flat and vehicles speed or static load are important to the track engineers to improve the design and maintenance methods in railway industry.

The Cambridge companion to creative writing [Edited book]

Creative writing has become a highly professionalised academic discipline, with popular courses and prestigious degree programmes worldwide. This book is a must for all students and teachers of creative writing, indeed for anyone who aspires to be a published writer. It engages with a complex art in an accessible manner, addressing concepts important to the rapidly growing field of creative writing, while maintaining a strong craft emphasis, analysing exemplary models of writing and providing related writing exercises. Written by professional writers and teachers of writing, the chapters deal with specific genres or forms – ranging from the novel to new media – or with significant topics that explore the cutting edge state of creative writing internationally (including creative writing and science, contemporary publishing and new workshop approaches).

Calculation of engine parameters using reconfigurable hardware

The feasibility of real-time calculation of parameters for an internal combustion engine via reconfigurable hardware implementation is investigated as an alternative to software computation. A detailed in-hardware field programmable gate array (FPGA)-based design is developed and evaluated using input crank angle and in-cylinder pressure data from fully instrumented diesel engines in the QUT Biofuel Engine Research Facility (BERF). Results indicate the feasibility of employing a hardware-based implementation for real-time processing for speeds comparable to the data sampling rate currently used in the facility, with acceptably low level of discrepancies between hardware and software-based calculation of key engine parameters.

Value management in infrastructure project design : unlocking the project team’s creativity

Value Management (VM) is a proven methodology that provides a structured framework using supporting tools and techniques that facilitate effective decision-making in many types of projects, thus achieving ‘best value’ for clients. It offers an exceptionally robust approach to exploring the need and function of projects to be aligned with client’s objectives. The functional analysis and creativity phases of VM are crucial as it focused on utilising innovative thinking to understand the objectives of clients’ projects and provide value-adding solutions at the early discovery stages of projects. There is however a perception of VM as just being another cost-cutting tool, which has overshadowed the fundamental benefits of the method, therefore negating both influence and wider use in the construction industry. This paper describes findings from a series of case studies conducted at project and corporate levels of a current public funded infrastructure projects in Malaysia. The study aims to investigate VM processes practised by the project client organisation and evaluate the effects of project team involvement in VM workshops during the design-stage of these projects. The focus of the study is on how issues related to ‘upstream’ infrastructure design aimed at improving ‘downstream’ construction process on-site, are being resolved through multi-disciplinary team consideration and decision-making. Findings from the case studies indicate that the mix of disciplines of project team members at a design-stage of a VM workshop has minimal influence on improving construction processes. However, the degree of interaction, institutionalized thinking, cultural dimensions and visualization aids adopted, have a significant impact in maximizing creativity amongst project team members during VM workshop. The case studies conducted for this research have focused on infrastructure projects that utilise traditional VM workshop as client’s chosen VM methodology to review and develop designs. Documents review and semi-structured interview with project teams are used as data collection techniques for the case study. The significant outcomes of this research are expected to offer alternative perspectives for construction professionals and clients to minimise the constraints and strengthen strategies for implementing VM on future projects.

Airborne collision scenario flight tests : impact of angle measurement errors on reactive vision-based avoidance control

The future emergence of many types of airborne vehicles and unpiloted aircraft in the national airspace means collision avoidance is of primary concern in an uncooperative airspace environment. The ability to replicate a pilot’s see and avoid capability using cameras coupled with vision based avoidance control is an important part of an overall collision avoidance strategy. But unfortunately without range collision avoidance has no direct way to guarantee a level of safety. Collision scenario flight tests with two aircraft and a monocular camera threat detection and tracking system were used to study the accuracy of image-derived angle measurements. The effect of image-derived angle errors on reactive vision-based avoidance performance was then studied by simulation. The results show that whilst large angle measurement errors can significantly affect minimum ranging characteristics across a variety of initial conditions and closing speeds, the minimum range is always bounded and a collision never occurs.

The International regulation of persons displaced by climate change

It is certain that there will be changes in environmental conditions across the globe as a result of climate change. Such changes will require the building of biological, human and infrastructure resilience. In some instances the building of such resilience will be insufficient to deal with extreme changes in environmental conditions and legal frameworks will be required to provide recognition and support for people dislocated because of environmental change. Such dislocation may occur internally within the country of original origin or externally into another State’s territory. International and national legal frameworks do not currently recognise or assist people displaced as a result of environmental factors including displacement occurring as a result of climate change. Legal frameworks developed to deal with this issue will need to consider the legal rights of those people displaced and the legal responsibilities of those countries required to respond to such displacement. The objective of this article is to identify the most suitable international institution to host a program addressing climate displacement. There are a number of areas of international law that are relevant to climate displacement, including refugee law, human rights law and international environmental law. These regimes, however, were not designed to protect people relocating as a result of environmental change. As such, while they indirectly may be of relevance to climate displacement, they currently do nothing to directly address this complex issue. In order to determine the most appropriate institution to address and regulate climate displacement, it is imperative to consider issues of governance. This paper seeks to examine this issue and determine whether it is preferable to place climate displacement programs into existing international legal frameworks or whether it is necessary to regulate this area in an entirely new institution specifically designed to deal with the complex and cross-cutting issues surrounding the topic. Commentators in this area have proposed three different regulatory models for addressing climate displacement. These models include: (a) Expand the definition of refugee under the Refugee Convention to encompass persons displaced by climate change; (b) Implement a new stand alone Climate Displacement Convention; and (c) Implement a Climate Displacement Protocol to the UNFCCC. This article will examine each of these proposed models against a number of criteria to determine the model that is most likely to address the needs and requirements of people displaced by climate change. It will also identify the model that is likely to be most politically acceptable and realistic for those countries likely to attract responsibilities by its implementation. In order to assess whether the rights and needs of the people to be displaced are to be met, theories of procedural, distributive and remedial justice will be used to consider the equity of the proposed schemes. In order to consider the most politically palatable and realistic scheme, reference will be made to previous state practice and compliance with existing obligations in the area. It is suggested that the criteria identified by this article should underpin any future climate displacement instrument.

A coupled SPH/FEM analysis of portable water filled barriers

Portable water filled barriers (PWFB) are semi-rigid roadside barriers which have the potential to display good crash attenuation characteristics at low and moderate impact speeds. The traditional mesh based numerical methods alone fail to simulate this type of impact with precision, stability and efficiency. This paper proposes to develop an advanced simulation model based on the combination of Smoothed Particles Hydrodynamics (SPH), a meshless method, and finite element method (FEM) for fluid-structure analysis using the commercially available software package LS-Dyna. The interaction between SPH particles and FEA elements is studied in this paper. Two methods of element setup at the element boundary were investigated. The response of the impacted barrier and fluid inside were analysed and compared. The system response and lagging were observed and reported in this paper. It was demonstrated that coupled SPH/FEM can be used in full scale PWFB modelling application. This will aid the research in determining the best initial setup to couple FEA and SPH in road safety barrier for impact response and safety analysis in the future.

Effects of average speed enforcement on speed compliance and crashes : a review of the literature

Average speed enforcement is a relatively new approach gaining popularity throughout Europe and Australia. This paper reviews the evidence regarding the impact of this approach on vehicle speeds, crashes rates and a number of additional road safety and public health outcomes. The economic and practical viability of the approach as a road safety countermeasure is also explored. A literature review, with an international scope, of both published and grey literature was conducted. There is a growing body of evidence to suggest a number of road safety benefits associated with average speed enforcement, including high rates of compliance with speed limits, reductions in average and 85th percentile speeds and reduced speed variability between vehicles. Moreover, the approach has been demonstrated to be particularly effective in reducing excessive speeding behaviour. Reductions in crash rates have also been reported in association with average speed enforcement, particularly in relation to fatal and serious injury crashes. In addition, the approach has been shown to improve traffic flow, reduce vehicle emissions and has also been associated with high levels of public acceptance. Average speed enforcement offers a greater network-wide approach to managing speeds that reduces the impact of time and distance halo effects associated with other automated speed enforcement approaches. Although comparatively expensive it represents a highly reliable approach to speed enforcement that produces considerable returns on investment through reduced social and economic costs associated with crashes.

Effects of schedule pressure on construction performance

Accelerating a project can be rewarding. The consequences, however, can be troublesome if productivity and quality are sacrificed for the sake of remaining ahead of schedule, such that the actual schedule benefits are often barely worth the effort. The tradeoffs and paths of schedule pressure and its causes and effects are often overlooked when schedule decisions are being made. This paper analyses the effects that schedule pressure has on construction performance, and focuses on tradeoffs in scheduling. A research framework has been developed using a causal diagram to illustrate the cause-and-effect analysis of schedule pressure. An empirical investigation has been performed by using survey data collected from 102 construction practitioners working in 38 construction sites in Singapore. The results of this survey data analysis indicate that advantages of increasing the pace of work—by working under schedule pressure—can be offset by losses in productivity and quality. The negative effects of schedule pressure arise mainly by working out of sequence, generating work defects, cutting corners, and losing the motivation to work. The adverse effects of schedule pressure can be minimized by scheduling construction activities realistically and planning them proactively, motivating workers, and by establishing an effective project coordination and communication mechanism.

Timed Up and Go Tests in cardiac rehabilitation : reliability and comparison with the 6-minute walk test

PURPOSE: To test the reliability of Timed Up and Go Tests (TUGTs) in cardiac rehabilitation (CR) and compare TUGTs to the 6-Minute Walk Test (6MWT) for outcome measurement. METHODS: Sixty-one of 154 consecutive community-based CR patients were prospectively recruited. Subjects undertook repeated TUGTs and 6MWTs at the start of CR (start-CR), postdischarge from CR (post-CR), and 6 months postdischarge from CR (6 months post-CR). The main outcome measurements were TUGT time (TUGTT) and 6MWT distance (6MWD). RESULTS: Mean (SD) TUGTT1 and TUGTT2 at the 3 assessments were 6.29 (1.30) and 5.94 (1.20); 5.81 (1.22) and 5.53 (1.09); and 5.39 (1.60) and 5.01 (1.28) seconds, respectively. A reduction in TUGTT occurred between each outcome point (P ≤ .002). Repeated TUGTTs were strongly correlated at each assessment, intraclass correlation (95% CI) = 0.85 (0.76–0.91), 0.84 (0.73–0.91), and 0.90 (0.83–0.94), despite a reduction between TUGTT1 and TUGTT2 of 5%, 5%, and 7%, respectively (P ≤ .006). Relative decreases in TUGTT1 (TUGTT2) occurred from start-CR to post-CR and from start-CR to 6 months post-CR of −7.5% (−6.9%) and −14.2% (−15.5%), respectively, while relative increases in 6MWD1 (6MWD2) occurred, 5.1% (7.2%) and 8.4% (10.2%), respectively (P < .001 in all cases). Pearson correlation coefficients for 6MWD1 to TUGTT1 and TUGTT2 across all times were −0.60 and −0.68 (P < .001) and the intraclass correlations (95% CI) for the speeds derived from averaged 6MWDs and TUGTTs were 0.65 (0.54, 0.73) (P < .001). CONCLUSIONS: Similar relative changes occurred for the TUGT and the 6MWT in CR. A significant correlation between the TUGTT and 6MWD was demonstrated, and we suggest that the TUGT may provide a related or a supplementary measurement of functional capacity in CR.

Chinese media

From an area of specialist research a decade ago China’s media has become now an important element of research and teaching worldwide, not only in specific Chinese cultural studies courses at the university level but increasingly in post-graduate research and in the domain of business consultancy. Edited by Michael Keane and Wanning Sun, leading experts in the field, this new title is a ‘mini library’ of the foundational and the very best cutting-edge scholarship on Chinese media

Featureless visual processing for SLAM in changing outdoor environments

Vision-based SLAM is mostly a solved problem providing clear, sharp images can be obtained. However, in outdoor environments a number of factors such as rough terrain, high speeds and hardware limitations can result in these conditions not being met. High speed transit on rough terrain can lead to image blur and under/over exposure, problems that cannot easily be dealt with using low cost hardware. Furthermore, recently there has been a growth in interest in lifelong autonomy for robots, which brings with it the challenge in outdoor environments of dealing with a moving sun and lack of constant artificial lighting. In this paper, we present a lightweight approach to visual localization and visual odometry that addresses the challenges posed by perceptual change and low cost cameras. The approach combines low resolution imagery with the SLAM algorithm, RatSLAM. We test the system using a cheap consumer camera mounted on a small vehicle in a mixed urban and vegetated environment, at times ranging from dawn to dusk and in conditions ranging from sunny weather to rain. We first show that the system is able to provide reliable mapping and recall over the course of the day and incrementally incorporate new visual scenes from different times into an existing map. We then restrict the system to only learning visual scenes at one time of day, and show that the system is still able to localize and map at other times of day. The results demonstrate the viability of the approach in situations where image quality is poor and environmental or hardware factors preclude the use of visual features.

Editorial: The Human Fertilisation and Embryology Act 2008

This editorial first describes the workshop out of which the present special issue arose. The editors then identify the need for a multidisciplinary collection examining the Human Fertilisation and Embryology Act 2008 from both legal and political perspectives, including the consultation process, campaigning and parliamentary debates leading to its passage, and the concluded legislation and its effects. The editorial provides an overview of the legislative reform process, key legislative changes, and the various contributions to the special issue. Cross-cutting themes include the value of a qualitative, discourse-based approach to research in this area; the need to understand the 2008 Act in historical context; unforeseen practical implications of the legislative provisions; and silences and missed opportunities in the legislation. Finally, a postscript covers the changing landscape of hybrid embryo research since the passage of the Act, and the uncertain future of the Human Fertilisation and Embryology Authority at the time of writing.

The stitchery collective

The stitchery collective is fashion-based design collective. Founded in February 2010 the collective brings together creative practitioners from across an expanded field of fashion design to develop innovative new models for both the design, production and consumption of fashion in the 21st century. Under the broad question "can fashion be more than pretty clothes for pretty people?" the collective has developed a range of workshops, exhibitions and creative projects that both engage the wider public and targeted community groups. The projects include "consciousness raising: up cycling workshops, zero-waste pattern cutting workshops, and sewing workshops with members of Brisbane's Karen, Sudansese, and Iraqi communities. Through these projects we test how innovative fashion design practice can engage with questions of environmental sustainability, ethical practices, and social inclusion. Established around a set of people -centred values, the stitchery collective therefore seeks to re-cast fashion as a 'less bad' field of creative endeavor and, one that sustains, inspires and connects individuals and communities. In seeking to develop new models of fashion practice that are socially oriented and environmentally responsible the stitchery outcomes align with the broader field of Design for Sustainability.

Safety enhancement of water-filled road safety barrier using interaction of composite materials

Road safety barriers are used to redirect traffic at roadside work-zones. When filled with water, these barriers are able to withstand low to moderate impact speeds up to 50kmh-1. Despite this feature, Portable Water-filled barriers (PWFB) face challenges such as large lateral displacements, tearing and breakage during impact; especially at higher speeds. This study explores the use of composite action to enhance the crashworthiness of PWFBs and enable their usage at higher speeds. Initially, energy absorption capability of water in PWFB is investigated. Then, composite action of the PWFB with the introduction of steel frame is considered to evaluate its enhanced impact performance. Findings of the study show that the initial height of the impact must be lower than the free surface level of water in a PWFB in order for the water to provide significant crash energy absorption. In general, an impact of a road barrier with 80% filled is a good estimation. Furthermore, the addition of a composite structure greatly reduces the probability of tearing by decreasing the strain and impact energy transferred to the shell container. This allows the water to remain longer in the barrier to absorb energy via inertial displacements and sloshing response. Information from this research will aid in the design of new generation roadside safety structures aimed to increase safety in modern roadways.