The failure tolerance of mechatronic software systems to random and targeted attacks

This paper describes a complex networks approach to study the failure tolerance of mechatronic software systems under various types of hardware and/or software failures. We produce synthetic system architectures based on evidence of modular and hierarchical modular product architectures and known motifs for the interconnection of physical components to software. The system architectures are then subject to various forms of attack. The attacks simulate failure of critical hardware or software. Four types of attack are investigated: degree centrality, betweenness centrality, closeness centrality and random attack. Failure tolerance of the system is measured by a 'robustness coefficient', a topological 'size' metric of the connectedness of the attacked network. We find that the betweenness centrality attack results in the most significant reduction in the robustness coefficient, confirming betweenness centrality, rather than the number of connections (i.e. degree), as the most conservative metric of component importance. A counter-intuitive finding is that "designed" system architectures, including a bus, ring, and star architecture, are not significantly more failure-tolerant than interconnections with no prescribed architecture, that is, a random architecture. Our research provides a data-driven approach to engineer the architecture of mechatronic software systems for failure tolerance.Comment: Proceedings of the 2013 ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2013 August 4-7, 2013, Portland, Oregon, USA (In Print

Young people's use of NHS Direct: a national study of symptoms and outcome of calls for children aged 0-15

Objectives National Health Service (NHS) Direct provides 24/7 expert telephone-based healthcare information and advice to the public in England. However, limited research has explored the reasons to why calls are made on behalf of young people, as such this study aimed to examine call rate (CR) patterns in younger people to enable a better understanding of the needs of this population in England. Setting NHS Direct, England, UK. Participants and methods CRs (expressed as calls/100 persons/annum) were calculated for all calls (N=358 503) made to NHS Direct by, or on behalf of, children aged 0–15 during the combined four ‘1-month’ periods within a year (July 2010, October 2010, January 2011 and April 2011). χ² Analysis was used to determine the differences between symptom, outcome and date/time of call. Results For infants aged <1, highest CRs were found for ‘crying’ for male (n=14, 440, CR=13.61) and female (n=13 654, CR=13.46) babies, which is used as a universal assessment applied to all babies. High CRs were also found for symptoms relating to ‘skin/hair/nails’ and ‘colds/flu/sickness’ for all age groups, whereby NHS Direct was able to support patients to self-manage and provide health information for these symptoms for 59.7% and 51.4% of all cases, respectively. Variations in CRs were found for time and age, with highest peaks found for children aged 4–15 in the 15:00–23:00 period and in children aged <1 in the 7:00–15:00 period. Conclusions This is the first study to examine the symptoms and outcome of calls made to NHS Direct for and on behalf of young children. The findings revealed how NHS Direct has supported a range of symptoms through the provision of health information and self-care support which provides important information about service planning and support for similar telephone-based services

Robust Design Review Conversations

Design reviews and executive conversations at the point of strategic decision-making share an important outcome: they both result in the (nearly) irrevocable allocation of resources to pursue a design concept or strategic option. Our study aims to contribute to the strategic decision-making scholarship by investigating the robustness of these conversations. We define a robust design review conversation as one in which the participants discuss evidence in favor of and against the option and at the same time propose new hypotheses to explain or resolve the evidence in favor of and against the option, hypotheses that can eventually be tested. We describe this second process as generative sensing. Whereas the first process is likely to rely on deductive reasoning from established rules to a definitive conclusion, the second is likely to rely on abductive reasoning, a form of reasoning that generates new hypotheses that are candidate parsimonious explanations for the evidence. We analyze and compare the design review conversations from a junior-level undergraduate course in industrial design and an entrepreneurship course. We find more instances of generative sensing in the industrial design review sessions than in the entrepreneurship project presentations. We believe that generative sensing serves three instrumental purposes: to resolve problems; to provide signals on option quality; and, to test the commitment to the present design concept

Exposure to dust and respiratory health among Australian miners

Purpose: Occupational exposure to dust has been recognised as a significant health hazard to mine workers. This study aimed to investigate the association between exposure to inhalable (INH) and respirable (RES) dust and respiratory health among mine workers in Western Australia using an industry-wide exposure database. Methods: The database comprised cross-sectional surveys conducted by mining companies for the period 2001–2012. The study population consisted of 12,797 workers who were monitored for exposure to INH and RES dust and undertook health assessments including a respiratory questionnaire and spirometry test. Results: Despite the general trend of declining exposure to both INH and RES dust observed over the 12 years period, mine workers reported a higher prevalence of phlegm and cough when exposed to elevated concentrations of INH and RES dust. Logistic regression analysis further confirmed the positive association between INH dust exposure and the prevalence of phlegm with an adjusted odds ratio of 1.033 (95% CI 1.012–1.052). Overall, 6.3% of miners might have potential airway obstruction, and exposure to INH dust was associated with impaired lung function parameters. Conclusion: Exposure levels of INH and RES dust particles among mine workers have reduced considerably and were well below currently legislated occupational exposure limits. However, given the reported higher prevalence of phlegm and cough among those with elevated dust concentrations, there is a continued need for effective dust exposure monitoring and control in the mineral mining industry

A Comparison of Formal Methods for Evaluating the Language of Preference in Engineering Design

In design, as with many fields, the bases of decisions are generally not formally modeled but only talked or written about. The research problem addressed in this paper revolves around the problem of modeling the direct evaluation of design alternatives and their attributes as they are realized in linguistic communication. The question is what types of linguistic data provide the most reliable linguistic displays of preference and utility. The paper compares two formal methods for assessing a design team’s preferences for alternatives based on the team’s discussion: APPRAISAL and Preferential Probabilities from Transcripts (PPT). Results suggest that the two methods are comparable in their assessment of preferences. This paper also examines the nature of consistency in the way design teams consider the attributes of a design. Findings suggest that assessment of an attribute can change substantially over time.National Science Foundation (U.S.) (Award CMMI- 0900255)Australian Research Council (Discovery Projects funding scheme (project number DP1095601)

Interplay of scripts and resistance in a participatory workshop.

The article reports on a participatory workshop in which we were faced with two different types of resistance. We employ the notion of scripts to describe how this resistance emerged. On the one hand, we explain how a weak script caused distrust of the workshop rationale, while on the other, we explain how a strong script rendered the technological materials of the workshop useless and led to termination of the activity. We suggest that structuring workshops according to the notion of scripts may prove a useful way of exercising and learning from resistance and expanding our territory of exploration

Epidemiology and Prevention of Prostate Cancer in Vietnam

Prostate cancer is the second most common cancer in men worldwide and a leading cause of mortality. Incidences continues to rise and vary substantially between populations. Although the prevalence of prostate cancer is relatively low in Vietnam, some hospital-based reports have shown an upward trend in recent years. While certain non-modifiable factors such as age, race and genetics are known to be mainly responsible, the literature has also suggested that environmental exposures can delay the onset of this disease. The present study provides a review of the epidemiology of prostate cancer in Vietnam by systematically searching several electronic databases. The results confirm an increasing trend of prostate cancer over the past decade, with age-standardised rate more than doubled from 2.2 per 100,000 men in 2000 to 4.7 per 100,000 men in 2010. However, no study has been found on modifiable risk factors, with the exception of one in vitro experiment that showed the inhibitory effect of garlic on the growth of prostate cancer cells. The lack of epidemiological information poses a difficulty to develop public health interventions to prevent this emerging malignant disease in Vietnam

Design and Development of a Slender Dual-Structure Continuum Robot for In-Situ Aeroengine Repair

© 2018 IEEE. In-situ aeroengine maintenance works (e.g. inspection, repair) are highly beneficial as it can significantly reduce currently accepted maintenance cycle which is extensive and costly due to the need to remove engines from the wing of an aircraft. However, feeding in/out via inspection ports and performing a multi-axis movement of an end-effector in a very constrained environment such as aeroengine combustion chamber is a fairly challenging task. This paper presents the design and development of a highly slender (i.e., low diameter-to-length ratio) dual-structure continuum robot with 16 degrees of freedom (DoFs) to provide the feeding motion needed to navigate into confined environments and then perform a required configuration shape for further repair operation. This continuum robot is a compact system and presents a set of innovative mechatronic solutions such as: (i) two-stage tendon-driven structure with bevelled disk design to perform required configuration shape and to provide selective stiffness for the ability of taking high payloads; (ii) various compliant joints to enable different flexibility requirement in each stage; (iii) three commanding cables for each 2- DoF section to minimise the number of actuators with a precise actuation. To be able to achieve the desired configuration shape, a kinematic model has been established and the configuration-cable kinematics has been implemented. Finally, the continuum robot has been built and tested for performing the predefined configuration shape