Prognostic modelling options for remaining useful life estimation by industry

Over recent years a significant amount of research has been undertaken to develop prognostic models that can be used to predict the remaining useful life of engineering assets. Implementations by industry have only had limited success. By design, models are subject to specific assumptions and approximations, some of which are mathematical, while others relate to practical implementation issues such as the amount of data required to validate and verify a proposed model. Therefore, appropriate model selection for successful practical implementation requires not only a mathematical understanding of each model type, but also an appreciation of how a particular business intends to utilise a model and its outputs. This paper discusses business issues that need to be considered when selecting an appropriate modelling approach for trial. It also presents classification tables and process flow diagrams to assist industry and research personnel select appropriate prognostic models for predicting the remaining useful life of engineering assets within their specific business environment. The paper then explores the strengths and weaknesses of the main prognostics model classes to establish what makes them better suited to certain applications than to others and summarises how each have been applied to engineering prognostics. Consequently, this paper should provide a starting point for young researchers first considering options for remaining useful life prediction. The models described in this paper are Knowledge-based (expert and fuzzy), Life expectancy (stochastic and statistical), Artificial Neural Networks, and Physical models.

Elasto-plastic stress analysis of an insulated rail joint (IRJ) with a loading below shakedown limit

A finite element numerical simulation is carried out to examine stress distributions on railhead in the vicinity of the endpost of a insulated rail joint. The contact patch and pressure distribution are considered using modified Hertzian formulation. A combined elasto-plastic material modelling available in Abaqus is employed in the simulation. A dynamic load factor of 1.21 is considered in modelling for the wheel load based on a previous study as part of this on going research. Shakedown theorem is employed in this study. A peak pressure load which is above the shakedown limit is determined as input load. As a result, a progressive damage in the railhead has been captured as depicted in the equivalent plastic strain plot.

Simulation of inplane and out of plane AE source in thin plate

In most materials, short stress waves are generated during the process of plastic deformation, phase transformation, crack formation and crack growth. These phenomena are applied in acoustic emission (AE) for the detection of material defects in a wide spectrum of areas, ranging from nondestructive testing for the detection of materials defects to monitoring of microseismical activity. AE technique is also used for defect source identification and for failure detection. AE waves consist of P waves (primary longitudinal waves), S waves (shear/transverse waves) and Rayleigh (surface) waves as well as reflected and diffracted waves. The propagation of AE waves in various modes has made the determination of source location difficult. In order to use acoustic emission technique for accurate identification of source, an understanding of wave propagation of the AE signals at various locations in a plate structure is essential. Furthermore, an understanding of wave propagation can also assist in sensor location for optimum detection of AE signals along with the characteristics of the source. In real life, as the AE signals radiate from the source it will result in stress waves. Unless the type of stress wave is known, it is very difficult to locate the source when using the classical propagation velocity equations. This paper describes the simulation of AE waves to identify the source location and its characteristics in steel plate as well as the wave modes. The finite element analysis (FEA) is used for the numerical simulation of wave propagation in thin plate. By knowing the type of wave generated, it is possible to apply the appropriate wave equations to determine the location of the source. For a single plate structure, the results show that the simulation algorithm is effective to simulate different stress waves.

Re-conceiving the good life : the key to sustainable globalisation

Resource-intensive, high-carbon, Western lifestyles are frequently criticised as unsustainable and deeply unsatisfying. However, these lifestyles are still attractive to the majority of Westerners and to a high proportion of the developing world’s middle classes. This paper argues that the imminent threat of catastrophic climate change constitutes an immediate political, economic and ethical challenge for citizens of the developed world that cannot be tackled by appeals to asceticism or restraint. There can be no solution to climate change until sustainable conceptions of the good life are developed that those in the west want to live and which others might want to live. While the ultimate solution to climate change is the development of low carbon lifestyles, it is important that government initiatives, governance arrangements and economic incentives support rather than undermine that search. Like the global financial crisis, the climate change crisis also demonstrates what happens when weaknesses in national, corporate and professional governance are exacerbated by weaknesses in global governance. In tackling the latter, it is critical the mistakes now evidenced in the former are avoided – including a rethinking of carbon market and carbon tax alternatives. It is also critical that individuals must take responsibility for their actions as consumers, voters and investors.

Ending the life of the act/omission dispute: Causation in withholding and withdrawing life-sustaining measures

My aim in this paper is to challenge the increasingly common view in the literature that the law on end of life decision making is in disarray and is in need of urgent reform. My argument is that this assessment of the law is based on assumptions about the relationship between the identity of the defendant and their conduct, and about the nature of causation, which, on examination, prove to be indefensible. I then provide a clarification of the relationship between causation and omissions which proves that the current legal position does not need modification, at least on the grounds that are commonly advanced for the converse view. This enables me, in conclusion, to clarify important conceptual and moral differences between withholding, refusing and withdrawing life-sustaining measures on the one hand, and assisted suicide and euthanasia, on the other.

Defending the sanctity of life principle : a reply to John Keown

This article is a response to Professor Keown’s criticism of my paper “Finding a Way Through the Ethical and Legal Maze: Withdrawal of Medical Treatment and Euthanasia” (2005) 13 (3) Medical Law Review 357. The article takes up and responds to a number of criticisms raised by Keown in an attempt to further the debate concerning the moral and legal status of withdrawing life-sustaining measures, its distinction from euthanasia, and the implications of the lawfulness of withdrawal for the principle of the sanctity of life.

Reconceiving the good life : the key to sustainable globalisation

Resource-intensive, high-carbon, Western lifestyles are frequently criticised as unsustainable and deeply unsatisfying. However, these lifestyles are still attractive to the majority of Westerners and to a high proportion of the developing world’s middle classes. This paper argues that the imminent threat of catastrophic climate change constitutes an immediate political, economic and ethical challenge for citizens of the developed world that cannot be tackled by appeals to asceticism or restraint. There can be no solution to climate change until sustainable conceptions of the good life are developed that those in the west want to live and which others might want to live. While the ultimate solution to climate change is the development of low carbon lifestyles, it is important that government initiatives, governance arrangements and economic incentives support rather than undermine that search. Like the global financial crisis, the climate change crisis also demonstrates what happens when weaknesses in national, corporate and professional governance are exacerbated by weaknesses in global governance. In tackling the latter, it is critical the mistakes now evidenced in the former are avoided – including a rethinking of carbon market and carbon tax alternatives. It is also critical that individuals must take responsibility for their actions as consumers, voters and investors.

Understanding nonsense : breathing life into shibboleths and killing critical thought in higher education

In this paper, I focus on the growing "nonsense industry" which is most apparent in the writing typical of business, government departments, and the financial press. This writing, like technical writing, is characterised by heavy reliance on grammatical metaphor. It endows shibboleths - for instance, "globalisation"; "efficiencies"; "competition"; "modernisation"; "consumer sentiment"; "reform"; and so on - with anthropomorphic qualities. These anthropomorphic artefacts of technocratised language are then presented as having immutable powers over people. Thus they become banal public excuses for negligent practices in both business and government.

A spoofing detection method for civilian L1 GPS and the E1-B Galileo Safety of Life service

This paper describes an effective method for signal-authentication and spoofing detection for civilian GNSS receivers using the GPS L1 C/A and the Galileo E1-B Safety of Life service. The paper discusses various spoofing attack profiles and how the proposed method is able to detect these attacks. This method is relatively low-cost and can be suitable for numerous mass-market applications. This paper is the subject of a pending patent.

Supportive-expressive group therapy for women with metastatic breast cancer: Improving access for Australian women through use of teleconference

While supportive-expressive group therapy (SEGT) has been found to be effective in significantly reducing distress associated with life-threatening illness, the challenge in Australia is to develop a means of providing supportive interventions to rural women who may be isolated both by the experience of illness and by geographical location. In this study an adaptation of SEGT was provided to women with metastatic breast cancer (n =21), who attended face-to-face or by telephone conference call. Participants showed significant gains on standardised measures of well-being, including a reduction in negative affect and an increase in positive affect, over a 12-month period. A reduction in intrusive and avoidant stress symptoms was also observed over 12 months; however, this difference was not significant. These outcomes suggest that SEGT, delivered in an innovative way within a community setting, may be an effective means of moderating the adverse effects of a diagnosis of metastatic breast cancer while improving access to supportive care for rural women. These results are considered exploratory, as the study did not include a matched control group.