Robot path planning in dynamic environments using a simulated annealing based approach

Mobile robots are widely used in many industrial fields. Research on path planning for mobile robots is one of the most important aspects in mobile robots research. Path planning for a mobile robot is to find a collision-free route, through the robot’s environment with obstacles, from a specified start location to a desired goal destination while satisfying certain optimization criteria. Most of the existing path planning methods, such as the visibility graph, the cell decomposition, and the potential field are designed with the focus on static environments, in which there are only stationary obstacles. However, in practical systems such as Marine Science Research, Robots in Mining Industry, and RoboCup games, robots usually face dynamic environments, in which both moving and stationary obstacles exist. Because of the complexity of the dynamic environments, research on path planning in the environments with dynamic obstacles is limited. Limited numbers of papers have been published in this area in comparison with hundreds of reports on path planning in stationary environments in the open literature. Recently, a genetic algorithm based approach has been introduced to plan the optimal path for a mobile robot in a dynamic environment with moving obstacles. However, with the increase of the number of the obstacles in the environment, and the changes of the moving speed and direction of the robot and obstacles, the size of the problem to be solved increases sharply. Consequently, the performance of the genetic algorithm based approach deteriorates significantly. This motivates the research of this work. This research develops and implements a simulated annealing algorithm based approach to find the optimal path for a mobile robot in a dynamic environment with moving obstacles. The simulated annealing algorithm is an optimization algorithm similar to the genetic algorithm in principle. However, our investigation and simulations have indicated that the simulated annealing algorithm based approach is simpler and easier to implement. Its performance is also shown to be superior to that of the genetic algorithm based approach in both online and offline processing times as well as in obtaining the optimal solution for path planning of the robot in the dynamic environment. The first step of many path planning methods is to search an initial feasible path for the robot. A commonly used method for searching the initial path is to randomly pick up some vertices of the obstacles in the search space. This is time consuming in both static and dynamic path planning, and has an important impact on the efficiency of the dynamic path planning. This research proposes a heuristic method to search the feasible initial path efficiently. Then, the heuristic method is incorporated into the proposed simulated annealing algorithm based approach for dynamic robot path planning. Simulation experiments have shown that with the incorporation of the heuristic method, the developed simulated annealing algorithm based approach requires much shorter processing time to get the optimal solutions in the dynamic path planning problem. Furthermore, the quality of the solution, as characterized by the length of the planned path, is also improved with the incorporated heuristic method in the simulated annealing based approach for both online and offline path planning.

Testing the effectiveness of a Practice Development intervention on changing the culture of evidence based practice in an acute care environment

In this age of evidence-based practice, nurses are increasingly expected to use research evidence in a systematic and judicious way when making decisions about patient care practices. Clinicians recognise the role of research when it provides valid, realistic answers in practical situations. Nonetheless, research is still perceived by some nurses as external to practice and implementing research findings into practice is often difficult. Since its conceptual platform in the 1960s, the emergence and growth of Nursing Development Units, and later, Practice Development Units has been described in the literature as strategic, organisational vehicles for changing the way nurses think about nursing by promoting and supporting a culture of inquiry and research-based practice. Thus, some scholars argue that practice development is situated in the gap between research and practice. Since the 1990s, the discourse has shifted from the structure and outcomes of developing practice to the process of developing practice, using a Practice Development methodology; underpinned by critical social science theory, as a vehicle for changing the culture and context of care. The nursing and practice development literature is dominated by descriptive reports of local practice development activity, typically focusing on reflection on processes or outcomes of processes, and describing perceived benefits. However, despite the volume of published literature, there is little published empirical research in the Australian or international context on the effectiveness of Practice Development as a methodology for changing the culture and context of care - leaving a gap in the literature. The aim of this study was to develop, implement and evaluate the effectiveness of a Practice Development model for clinical practice review and change on changing the culture and context of care for nurses working in an acute care setting. A longitudinal, pre-test/post-test, non-equivalent control group design was used to answer the following research questions: 1. Is there a relationship between nurses' perceptions of the culture and context of care and nurses' perceptions of research and evidence-based practice? 2. Is there a relationship between engagement in a facilitated process of Practice Development and change in nurses' perceptions of the culture and context of care? 3. Is there a relationship between engagement in a facilitated process of Practice Development and change in nurses' perceptions of research and evidence-based practice? Through a critical analysis of the literature and synthesis of the findings of past evaluations of Nursing and Practice Development structures and processes, this research has identified key attributes consistent throughout the chronological and theoretical development of Nursing and Practice Development that exemplify a culture and context of care that is conducive to creating a culture of inquiry and evidence-based practice. The study findings were then used in the development, validation and testing of an instrument to measure change in the culture and context of care. Furthermore, this research has also provided empirical evidence of the relationship of the key attributes to each other and to barriers to research and evidence-based practice. The research also provides empirical evidence regarding the effectiveness of a Practice Development methodology in changing the culture and context of care. This research is noteworthy in its contribution to advancing the discipline of nursing by providing evidence of the degree to which attributes of the culture and context of care, namely autonomy and control, workplace empowerment and constructive team dynamics, can be connected to engagement with research and evidence-based practice.

Developing a culture of enquiry to sustain evidence-based practice

Evidence-based practice (EBP) is having a significant effect on the health service environment. It constructs a language that bridges the healthcare disciplines and the clinical and managerial components of health services. Most experienced clinicians in nursing, medicine and allied health now recognise that the contemporary healthcare environment calls for our practice to be justified by sound, credible evidence. There is pressure on all clinicians to accommodate innovation, while at the same time ensuring their practice is effective, safe and efficient (Forbes & Griffiths 2002). Consequently, EBP in healthcare is having a profound effect on nursing and the way we think about nursing. There are many available models for research utilisation that are dependent on organisational strategies for change. This chapter describes the relationship between organisation and culture, and explores the notion of cultural change; that is, developing a culture of inquiry that can sustain evidence-based practice. We begin this chapter with a clear conception of what we mean by EBP and what we mean by ‘culture’.

Teachers reporting child sexual abuse : towards evidence-based reform of law, policy and practice

This report presents the results of the largest study ever conducted into the law, policy and practice of primary school teachers’ reporting of child sexual abuse in New South Wales, Queensland and Western Australia. The study included the largest Australian survey of teachers about reporting sexual abuse, in both government and non-government schools (n=470). Our research has produced evidence-based findings to enhance law, policy and practice about teachers’ reporting of child sexual abuse. The major benefits of our findings and recommendations are to: • Show how the legislation in each State can be improved; • Show how the policies in government and non-government school sectors can be improved; and • Show how teacher training can be improved. These improvements can enhance the already valuable contribution that teachers are making to identify cases of child sexual abuse. Based on the findings of our research, this report proposes solutions to issues in seven key areas of law, policy and practice. These solutions are relevant for State Parliaments, government and non-government educational authorities, and child protection departments. The solutions in each State are practicable, low-cost, and align with current government policy approaches. Implementing these solutions will: • protect more children from sexual abuse; • save cost to governments and society; • develop a professional teacher workforce better equipped for their child protection role; and • protect government and school authorities from legal liability.

A risk-based approach to course quality assurance

A decade ago, Queensland University of Technology (QUT) developed an innovative annual Courses Performance Report, but through incremental change, this report became quite labour-intensive. A new risk-based approach to course quality assurance, that consolidates voluminous data in a simple dashboard, responds to the changing context of the higher education sector. This paper will briefly describe QUT’s context and outline the second phase of implementation of this new approach to course quality assurance. The main components are: Individual Course Reports (ICRs), the Consolidated Courses Performance Report (CCPR), Underperforming Courses Status Update and the Strategic Faculty Courses Update (SFCU). These components together form a parsimonious and strategic annual cycle of reporting and place QUT in a positive position to respond to future sector change

Modelling the process of dialogic communication in public relations: a role-based approach

This paper takes Kent and Taylor’s (2002) call to develop a dialogic theory of public relations and suggests that a necessary first step is the modelling of the process of dialogic communication in public relations. In order to achieve this, extant literature from a range of fields is reviewed, seeking to develop a definition of dialogic communication that is meaningful to the practice of contemporary public relations. A simple transmission model of communication is used as a starting point. This is synthesised with concepts relating specifically to dialogue, taken here in its broadest sense rather than defined as any one particular outcome. The definition that emerges from this review leads to the conclusion that dialogic communication in public relations involves the interaction of three roles – those of sender, receiver, and responder. These three roles are shown to be adopted at different times by both participants involved in dialogic communication. It is further suggested that variations occur in how these roles are conducted: the sender and receiver roles can be approached in a passive or an active way, while the responder role can be classified as being either resistant or responsive to the information received in dialogic communication. The final modelling of the definition derived provides a framework which can be tested in the field to determine whether variations in the conduct of the roles in dialogic communication actually exist, and if so, whether they can be linked to the different types of outcome from dialogic communication identified previously in the literature.

Browser security : a requirements-based approach

A browser is a convenient way to access resources located remotely on computer networks. Security in browsers has become a crucial issue for users who use them for sensitive applications without knowledge ofthe hazards. This research utilises a structure approach to analyse and propose enhancements to browser security. Standard evaluation for computer products is important as it helps users to ensure that the product they use is appropriate for their needs. Security in browsers, therefore, has been evaluated using the Common Criteria. The outcome of this was a security requirements profile which attempts to formalise the security needs of browsers. The information collected during the research was used to produce a prototype model for a secure browser program. Modifications to the Lynx browser were made to demonstrate the proposed enhancements.

After the marketplace: evidence, social science and educational research

This paper is an essay on the state of Australian education that frames new directions for educational research. It outlines three challenges faced by Australian educators: highly spatialised poverty with particularly strong mediating effects on primary school education; the need for intellectual and critical depth in pedagogy, with a focus in the upper primary and middle years; and the need to reinvent senior schooling to address emergent pathways from school to work and civic life. It offers a narrative description of the dynamics of policy making in Australia and North America and argues for an evidence-based approach to social and educational policy – but one quite unlike current test and market-based approaches. Instead, it argues for a multidisciplinary approach to a broad range of empirical and case-based evidence that subjects these to critical, hermeneutic social sciences. Such an approach would join educational policy with educational research, and broader social, community and governmental action with the aim of reorganising and redistributing material, cultural and social resources.

Infant wrapping as an evidence-based strategy to encourage settling and the utilisation of the supine sleep position

Objective: To identify knowledge, attitudes and practices of child health nurses relating to infant wrapping as an effective settling/sleep strategy. Methods: A pre-test/post-test intervention design was used to explore knowledge, attitudes and practices relating to wrapping in a sample of child health nurses (n=182): a) pre-test survey; b) educational intervention incorporating evidence relating to infant wrapping; SIDS&KIDS endorsed infant wrapping pamphlet; Safe Sleeping recommendations. Emphasis was placed on infant wrapping as an effective settling strategy for parents to use as an alternative to prone positioning; c) post-test survey to evaluate intervention effectiveness. Results: Pretest results identified wide variation in nurses’ knowledge, attitudes and practices of infant wrapping as a settling/sleep strategy. The intervention increased awareness of wrapping guidelines and self-reported practices relating to parent advice. Significant positive changes in nurses’ awareness of wrapping guidelines (p<0.001); to wrap in supine position only (p<0.001); and parental advice to use wrapping as an alternative strategy to prone positioning to assist settling/sleep (p<0.01), were achieved post-test. Conclusions: Managing unsettled infants and promoting safe sleeping practices are issues routinely addressed by child health nurses working with parents of young infants. Queensland has a high incidence of prone sleeping. Infant wrapping is an evidence-based strategy to improve settling and promote supine sleep consistent with public health recommendations. Infant wrapping guidelines are now included in Queensland Health’s state policy and Australian SIDSandKids information relating to safe infant sleeping. In communicating complex health messages to parents, health professionals have a key role in reinforcing safe sleeping recommendations and offering safe, effective settling/sleep strategies to address the non-recommended use of prone positioning for unsettled infants.

Comparing cost uplift in infrastructure delivery methods : a case based approach

The alliance project delivery method is used for approximately one third of all Australian government infrastructure projects representing $8-$10 billion per annum. Despite its widespread use, little is known about the differences between estimated project cost and actual cost over the project lifecycle. This paper presents the findings of research into 14 Australian government alliance case studies investigating the observed cost uplift over each project’s lifecycle. I find that significant cost uplift is likely and that this uplift is greater than that afflicting traditional delivery methods. Furthermore, most of the cost uplift occurs at a different place in the project lifecycle, namely between Business Case and Contractual Commitment.

A probability-based approach for assessing the relationship between crash accidents and pavement properties

Skid resistance is a condition parameter characterising the contribution that a road makes to the friction between a road surface and a vehicle tyre. Studies of traffic crash histories around the world have consistently found that a disproportionate number of crashes occur where the road surface has a low level of surface friction and/or surface texture, particularly when the road surface is wet. Various research results have been published over many years and have tried to quantify the influence of skid resistance on accident occurrence and to characterise a correlation between skid resistance and accident frequency. Most of the research studies used simple statistical correlation methods in analysing skid resistance and crash data.----- ------ Preliminary findings of a systematic and extensive literature search conclude that there is rarely a single causation factor in a crash. Findings from research projects do affirm various levels of correlation between skid resistance and accident occurrence. Studies indicate that the level of skid resistance at critical places such as intersections, curves, roundabouts, ramps and approaches to pedestrian crossings needs to be well maintained.----- ----- Management of risk is an integral aspect of the Queensland Department of Main Roads (QDMR) strategy for managing its infrastructure assets. The risk-based approach has been used in many areas of infrastructure engineering. However, very limited information is reported on using risk-based approach to mitigate crash rates related to road surface. Low skid resistance and surface texture may increase the risk of traffic crashes.----- ----- The objectives of this paper are to explore current issues of skid resistance in relation to crashes, to provide a framework of probability-based approach to be adopted by QDMR in assessing the relationship between crash accidents and pavement properties, and to explain why the probability-based approach is a suitable tool for QDMR in order to reduce accident rates due to skid resistance.

Procurement strategies : a relationship-based approach

Construction has been an industry characterised by disputes, fierce competitiveness and fragmentation - all major obstacles to development. Now, however, a relationship-based approach to project procurement, through partnering and alliancing, aims to bring about a fundamental change. ----- ----- ----- This book addresses the critical relationship issues for a more collaborative and sustainable construction industry. It looks at how project procurement and project alliancing partner selection works, and how risk and crisis resolution are managed. It provides readers with guidance and models on how to put a relationship-based approach to procurement into practice, drawing on specific prototypes from an actual, successful project that can be adapted.

A national roll out of an insufficiently evaluated practice : how evidence based are our end-of-life care policies?

There has been increasing international efforts to ensure that health care policies are evidence based. One area where there is a lack of ‘effectiveness’ evidence is in the use of end-of-life care pathways (EOLCP) (1). Despite the lack of evidence supporting the efficacy of the EOCLP, their use has been endorsed in the recent national palliative care strategy document in the UK (2). In addition, a publication endorsed by the Australian Government (titled: Supporting Australians to live well at the End of Life- National Palliative Care Strategy 2010) (3), recommended a national roll out of EOLCP across all sectors (primary, acute and aged care) in Australia. According to this document, it is a measure of “appropriateness” and “effectiveness” for promoting quality end-of-life care.