Reliability and Condition-Based Maintenance Analysis of Deteriorating Systems Subject to Generalized Mixed Shock Model

For successful commercialization of evolving devices (e.g., micro-electro-mechanical systems, and biomedical devices), there must be new research focusing on reliability models and analysis tools that can assist manufacturing and maintenance of these devices. These advanced systems may experience multiple failure processes that compete against each other. Two major failure processes are identified to be deteriorating or degradation processes (e.g., wear, fatigue, erosion, corrosion) and random shocks. When these failure processes are dependent, it is a challenging problem to predict reliability of complex systems. This research aims to develop reliability models by exploring new aspects of dependency between competing risks of degradation-based and shock-based failure considering a generalized mixed shock model, and to develop new and effective condition-based maintenance policies based on the developed reliability models. In this research, different aspects of dependency are explored to accurately estimate the reliability of complex systems. When the degradation rate is accelerated as a result of withstanding a particular shock pattern, we develop reliability models with a changing degradation rate for four different shock patterns. When the hard failure threshold reduces due to changes in degradation, we investigate reliability models considering the dependence of the hard failure threshold on the degradation level for two different scenarios. More generally, when the degradation rate and the hard failure threshold can simultaneously transition multiple times, we propose a rich reliability model for a new generalized mixed shock model that is a combination of extreme shock model, δ-shock model and run shock model. This general assumption reflects complex behaviors associated with modern systems and structures that experience multiple sources of external shocks. Based on the developed reliability models, we introduce new condition-based maintenance strategies by including various maintenance actions (e.g., corrective replacement, preventive replacement, and imperfect repair) to minimize the expected long-run average maintenance cost rate. The decisions for maintenance actions are made based on the health condition of systems that can be observed through periodic inspection. The reliability and maintenance models developed in this research can provide timely and effective tools for decision-makers in manufacturing to economically optimize operational decisions for improving reliability, quality and productivity.Industrial Engineering, Department o

Reliability analysis and resilience measure of complex systems in shock events

The working environment of complex systems is complex and variable, and their performance is often affected by various shock events during the service phase. In this paper, first, considering that the system performance will be affected by shocks again in the process of maintenance, the reliability changes and fault process of complex systems are discussed. Second, the performance change processes of complex systems are analyzed under multiple shocks and maintenance. Then, based on performance loss and recovery, this paper analyzes the reliability and resilience of complex systems under the intersecting process of multiple shocks and maintenance. Considering the direct and indirect losses caused by shocks, as well as maintenance costs, the changes in total costs are analyzed. Finally, the practicability of the proposed model is checked by using a specific welding robot system

Rural Poverty and Disability in LMICs

Disability is neither a purely medical nor a purely social phenomenon. Rather, it is an outcome of their interplay. The main contributions of our study are two-fold: (i) a synthesis of the extant literature on the links between poverty and disability in LMICs. However, the studies focused on these links in rural areas are sparse. (ii) As rural economies-specifically, agriculture- continue to play an important role in economic growth, it is necessary to deepen our understanding of factors associated with rural disabilities, their association with rural employment and, finally, whether disabilities are associated with rural poverty. We use panel data for India and Ethiopia to illustrate these linkages, using rigorous econometric methodology. In particular, an important contribution is to corroborate the bidirectional association between disability and poverty, noted in many but validated in a few. The CRPD has ensured a concomitant shift in global initiatives, most notably the 2015 Sustainable Development Goals (SDGs) which explicitly recognise disability as a major impediment to elimination of poverty and hunger. In the current development discourse, disability has thus acquired high priority. Although there is a plethora of legislation banning discrimination against the disabled in LMICs-including India and Ethiopia and other LMICs-discrimination against disabled women and elderly is rampant. While it is imperative to fix the policy failures, a remedial strategy has to mainstream the disabled in a sustainable rural development framework, with a key role of the community and mass media in dismantling the barriers to the participation of the disabled in the political, economic and social spheres. Although the challenges are formidable, our study offers grounds for optimism

Cardiac Arrhythmias

The most intimate mechanisms of cardiac arrhythmias are still quite unknown to scientists. Genetic studies on ionic alterations, the electrocardiographic features of cardiac rhythm and an arsenal of diagnostic tests have done more in the last five years than in all the history of cardiology. Similarly, therapy to prevent or cure such diseases is growing rapidly day by day. In this book the reader will be able to see with brighter light some of these intimate mechanisms of production, as well as cutting-edge therapies to date. Genetic studies, electrophysiological and electrocardiographyc features, ion channel alterations, heart diseases still unknown , and even the relationship between the psychic sphere and the heart have been exposed in this book. It deserves to be read

Regulating Sex Work: Assimilationism, Erotic Exceptionalism and the Challenge of Intimate Labor

Most commentators on sex markets focus on the debate between abolitionists and those who defend and support professional sex work. This paper, instead, looks at debates within the pro-sex work camp, uncovering some unattended tensions and contradictions. It shows that, within this camp, some stress the labor aspect, urging that sex markets perpetuate a “vulnerable population” of workers, similar to others who perform highly risky and/or exploited labor, and should be regulated accordingly. In this view, sex work would be assimilated into other labor. Others, though, take a more anti-regulatory stance. They exceptionalize this form of labor, arguing that because it is sexual it should be exempt from state scrutiny and interference, claims which can quickly sound libertarian. In sum, while both camps agree that professional sex work should be decriminalized, when one turns from the criminal to the regulatory perspective, the paper shows how erotic exceptionalists and assimilationists could not be more opposed. The paper contends that neither of these views is satisfactory. Sex work could very well be legalized and regulated — if we have the political and moral will to do so. The paper explores a regulatory structure that might govern sex markets. Doing so requires a break with both assimilationism and erotic exceptionalism. This paper attempts two interventions into the sex work debate. The first move is a conceptual one, shifting the focus from disputes between abolitionists and sex work advocates to uncovering contradictions and ambivalences within the pro-sex work camp. It gives significant attention to these latent tensions, as I anticipate some readers steeped in feminist theory may dispute this as an issue. The second is a governance move, comparing sex work to other types of work to consider to what extent various risks and injuries of sex work, physical and otherwise, could be ameliorated by legalization — that is by appropriate state regulation. It pairs two regulatory claims. One contends that risk reduction is best served by correlating regulation to institutional form, or what I call sexual geography, which I do not anticipate will be that controversial. Another, which tackles discrimination from the demand side, that is, through the erotic preferences that comprise sex markets, should be provocative to many. In the end, my goal is to launch a conversation about whether the sex workplace really is like the factory floor

Regulating Sex Work: Assimilation, Erotic Exceptionalism & Beyond

Most commentators on sex markets focus on the debate between abolitionists and those who defend and support professional sex work. This paper, instead, looks at debates within the pro-sex work camp, uncovering some unattended tensions and contradictions. It shows that, within this camp, some stress the labor aspect, urging that sex markets perpetuate a vulnerable population of workers, similar to others who perform highly risky and/or exploited labor, and should be regulated accordingly. In this view, sex work would be assimilated into other labor. Others, though, take a more anti-regulatory stance. They exceptionalize this form of labor, arguing that because it is sexual it should be exempt from state scrutiny and interference, claims which can quickly sound libertarian. In sum, while both camps agree that professional sex work should be decriminalized, when one turns from the criminal to the regulatory perspective, the paper shows how erotic exceptionalists and assimilationists could not be more opposed. The paper contends that neither of these views is satisfactory. Sex work could very well be legalized and regulated — if we have the political and moral will to do so. The paper explores a regulatory structure that might govern sex markets. Doing so requires a break with both assimilationism and erotic exceptionalism. This paper attempts two interventions into the sex work debate. The first move is a conceptual one, shifting the focus from disputes between abolitionists and sex work advocates to uncovering contradictions and ambivalences within the pro-sex work camp. It gives significant attention to these latent tensions, as I anticipate some readers steeped in feminist theory may dispute this as an issue. The second is a governance move, comparing sex work to other types of work to consider to what extent various risks and injuries of sex work, physical and otherwise, could be ameliorated by legalization — that is by appropriate state regulation. It pairs two regulatory claims. One contends that risk reduction is best served by correlating regulation to institutional form, or what I call sexual geography, which I do not anticipate will be that controversial. Another, which tackles discrimination from the demand side, that is, through the erotic preferences that comprise sex markets, should be provocative to many. In the end, my goal is to launch a conversation about whether the sex workplace really is like the factory floor