Techniques for the Fast Simulation of Models of Highly dependable Systems

With the ever-increasing complexity and requirements of highly dependable systems, their evaluation during design and operation is becoming more crucial. Realistic models of such systems are often not amenable to analysis using conventional analytic or numerical methods. Therefore, analysts and designers turn to simulation to evaluate these models. However, accurate estimation of dependability measures of these models requires that the simulation frequently observes system failures, which are rare events in highly dependable systems. This renders ordinary Simulation impractical for evaluating such systems. To overcome this problem, simulation techniques based on importance sampling have been developed, and are very effective in certain settings. When importance sampling works well, simulation run lengths can be reduced by several orders of magnitude when estimating transient as well as steady-state dependability measures. This paper reviews some of the importance-sampling techniques that have been developed in recent years to estimate dependability measures efficiently in Markov and nonMarkov models of highly dependable system

Linking component importance to optimisation of preventive maintenance policy

In reliability engineering, time on performing preventive maintenance (PM) on a component in a system may affect system availability if system operation needs stopping for PM. To avoid such an availability reduction, one may adopt the following method: if a component fails, PM is carried out on a number of the other components while the failed component is being repaired. This ensures PM does not take system’s operating time. However, this raises a question: Which components should be selected for PM? This paper introduces an importance measure, called Component Maintenance Priority (CMP), which is used to select components for PM. The paper then compares the CMP with other importance measures and studies the properties of the CMP. Numerical examples are given to show the validity of the CMP

Health Related Quality of Life in Coronary Patients.

The increase observed in the survival of patients with ischemic cardiopathy, together with the effect of the disease on the social, professional, and family life of those suffering from it, have led researchers to consider that the traditional ways of measuring morbidity and mortality are not adequate for assessing the potential benefits of health care interventions. For this reason, there is common agreement on the need to use an indicator of subjective assessment of health, and of health related quality of life (HRQL), as a complementary criterion for monitoring the results of medical interventions in these patients. The term "quality of life" (QoL) or health related quality of life (HRQL) came into use during the 1970s as a multidimensional concept reflecting the overall subjective condition of the physical and mental welfare of the individual, which is a consequence not only of the disease but also of the family and social conditions forming the patient’s environment. The assessment of these patients’ HRQL has been tackled by several authors using both disease-specific and generic instruments such as the Nottingham Health Profile, the Sickness Impact Profile, the SF-36 or the SF-12 health questionnaire. Both types of instrument have advantages and disadvantages, and they may provide additional information since they quantify the patient’s overall health. Using different multidimensional measures, poorer HRQL has been observed in patients with Acute Myocardial Infarction (AMI) and angina pectoris than in other populations, and these differences have been related to low social class, female sex, the presence of mental disorders and the severity of the clinical condition. Measuring changes in the HRQL of coronary patients is also important as a way of assessing interventions and predicting needs for social care, because it has been shown that the focus of attention in the immediate period following a cardiac attack is generally the physical functioning, but following discharge from hospital and in the longer term, general health, vitality, social and emotional functions could be at least as important. In this chapter, we aim to provide an overview of the concept of HRQL and the usefulness of this measure from the perspective of a coronary patient. Likewise, we intend to review the main instruments used to assess HRQL and we analyse the factors that have been seen to affect the quality of life of these patients

Space technology's potential for industry

Space technology transfer to civilian applicatio

Recent Advances in Sustainable Winter Road Operations – A Book Proposal

Investing in winter transportation operations is essential and beneficial to the public and the economy. The U.S. economy cannot afford the cost of shutting down highways, airports, etc., during winter weather. In the northern U.S. and other cold-climate areas, winter maintenance operations are essential to ensure the safety, mobility, and productivity of transportation systems. Agencies are continually challenged to provide a high level of service and improve safety and mobility in a fiscally and environmentally responsible manner. To this end, it is desirable to use the most recent advances in the application of materials, practices, equipment, and other technologies. Such best practices are expected to improve the effectiveness and efficiency of winter operations, to optimize material usage, and to reduce associated annual spending, corrosion, and environmental impacts. Currently, no professional societies, scientific journals, or textbooks are dedicated solely to sustainable winter road operations, and key information is scattered across a variety of disciplines. The objective of the proposed book is to summarize the best practices and recent advances in sustainable winter road operations for the purposes of education and workforce development. This book is now in press and can be cited as follows: Shi, X., Fu, L. (2017). Sustainable Winter Road Operations (Eds.). ISBN: 978-1-119-18506-2. Wiley-Blackwell

Determination and evaluation of web accessibility

The Web is the most pervasive collaborative technology in widespread use today; however, access to the web and its many applications cannot be taken for granted. Web accessibility encompasses a variety of concerns ranging from societal, political, and economic to individual, physical, and intellectual through to the purely technical. Thus, there are many perspectives from which web accessibility can be understood and evaluated. In order to discuss these concerns and to gain a better understanding of web accessibility, an accessibility framework is proposed using as its base a layered evaluation framework from Computer Supported Co-operative Work research and the ISO standard, ISO/IEC 9126 on software quality. The former is employed in recognition of the collaborative nature of the web and its importance in facilitating communication. The latter is employed to refine and extend the technical issues and to highlight the need for considering accessibility from the viewpoint of the web developer and maintainer as well as the web user. A technically inaccessible web is unlikely to be evolved over time. A final goal of the accessibility framework is to provide web developers and maintainers with a practical basis for considering web accessibility through the development of a set of accessibility factors associated with each identified layer

Inter-rater reliability of the EPUAP pressure ulcer classification system using photographs

Background. Many classification systems for grading pressure ulcers are discussed in the literature. Correct identification and classification of a pressure ulcer is important for accurate reporting of the magnitude of the problem, and for timely prevention. The reliability of pressure ulcer classification systems has rarely been tested. Aims and objectives. The purpose of this paper is to examine the inter-rater reliability of classifying pressure ulcers according to the European Pressure Ulcer Advisory Panel classification system when using pressure ulcer photographs.Design. Survey was among pressure ulcer experts.Methods. Fifty-six photographs were presented to 44 pressure ulcer experts. The experts classified the lesions as normal skin, blanchable erythema, pressure ulcer (four grades) or incontinence lesion. Inter-rater reliability was calculated.Results. The multirater-Kappa for the entire group of experts was 0.80 (P < 0.001).Various groups of experts obtained comparable results. Differences in classifications are mainly limited to 1 degree of difference. Incontinence lesions are most often confused with grade 2 (blisters) and grade 3 pressure ulcers (superficial pressure ulcers).Conclusions. The inter-rater reliability of the European Pressure Ulcer Advisory Panel classification appears to be good for the assessment of photographs by experts. The difference between an incontinence lesion and a blister or a superficial pressure ulcer does not always seem clear.Relevance to clinical practice. The ability to determine correctly whether a lesion is a pressure ulcer lesion is important to assess the effectiveness of preventive measures. In addition, the ability to make a correct distinction between pressure ulcers and incontinence lesions is important as they require different preventive measures. A faulty classification leads to mistaken measures and negative results. Photographs can be used as a practice instrument to learn to discern pressure ulcers from incontinence lesions and to get to know the different grades of pressure ulcers. The Pressure Ulcer Classification software package has been developed to facilitate learning

Perceived Family Support, Acculturation, and Life Satisfaction in Mexican American Youth: A Mixed-Methods Exploration

In this article, the authors describe a mixed-methods study designed to explore perceived family support, acculturation, and life satisfaction among 266 Mexican American adolescents. Specifically, the authors conducted a thematic analysis of open-ended responses to a question about life satisfaction to understand participants’ perceptions of factors that contributed to their overall satisfaction with life. The authors also conducted hierarchical regression analyses to investigate the independent and interactive contributions of perceived support from family and Mexican and Anglo acculturation orientations on life satisfaction. Convergence of mixed-methods findings demonstrated that perceived family support and Mexican orientation were significant predictors of life satisfaction in these adolescents. Implications, limitations, and directions for further research are discussed

Being Mindful: A Long-term Investigation of an Interdisciplinary Course in Mindfulness

Background: Burnout and work-related stress in health-care professionals (HCPs) is a growing concern to the optimal functioning of the health-care system. Mindfulness-based interventions may be well-suited to address burnout in HCPs. Objective: The purpose of this study was (1) to quantitatively evaluate the effect of a mindfulness-based intervention for interdisciplinary HCPs over time and at a long-term follow-up and (2) to explore perceived benefits, facilitators, and barriers to the practice of mindfulness at the long-term follow-up. Design: A mixed-method, repeated measures, within-subjects design was used to investigate Mindfulness for Interdisciplinary HCPs (MIHP) at baseline, post-MIHP, and a follow-up (6 months to 1.5 years after MIHP). MIHP is an 8-week, group-based course for interdisciplinary HCPs and students, with weekly meditation training, gentle yoga, and discussions on the application of mindfulness to common stressors faced by HCPs. Main outcome measures were the Maslach Burnout Inventory—Health Services Survey and the Five Facet Mindfulness Questionnaire. A semistructured interview was used to explore participants’ perceptions of sustained effects and practice in the context of HCP work at the long-term follow-up. The study protocol was registered with ClinicalTrials.gov (NCT02736292). Results: Eighteen HCPs (88% female) participated in the study. Significant reductions were found after the intervention for 2 subscales of burnout: depersonalization, F(2, 17) = 5.98, P = .01, and emotional exhaustion, F(2, 17) = 2.64, P = .10. Three facets of dispositional mindfulness showed significant increases at long-term follow-up, act aware: F(2, 15) = 4.47, P = .03, nonjudge: F(2, 15) = 4.7, P = .03, and nonreactivity: F(2, 15) = 3.58, P = .05. Continued practice of skills long term was facilitated by the use of informal practice and perceived improvement in work and personal life. Conclusion: In sum, MIHP improved subscales of burnout and mindfulness. These findings should be further explored with a larger, controlled study. Interventions should focus on developing mindfulness practice that can be integrated into the work of HCPs