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A fuzzy data-driven reliability analysis for risk assessment and decision making using Temporal Fault Trees
No full textYesFuzzy data-driven reliability analysis has been used in different safety-critical domains for risk assessment and decision-making where precise failure data is non-existent. Expert judgements and fuzzy set theory have been combined with different variants of fault trees as part of fuzzy data-driven reliability analysis studies. In such fuzzy fault tree analyses, different people represented failure data using different membership functions for the fuzzy set, and different parameters were set differently in the expert opinion elicitation process. Due to the availability of a wide variety of options, it is possible to obtain different outcomes when choosing one option over another. This article performed an analysis in the context of fuzzy data-based temporal fault tree analysis to investigate the effect of choosing different membership functions on the estimated system reliability and criticality ranking of different failure events. Moreover, the effect of using different values for the relaxation factor, a parameter set during the expert elicitation process, was studied on the system reliability and criticality evaluation. The experiments on the fuel distribution system case study show system reliability did not vary when triangular and trapezoidal fuzzy numbers were used with the same upper and lower bounds. However, it was seen that the criticality rankings of a couple of events were changed due to choosing different membership functions and different values of relaxation facto
Evaluating 'living well' with mild-to-moderate dementia: Co-production and validation of the IDEAL My Life Questionnaire
Get PDFYesWe aimed to co-produce and validate an accessible, evidence-based questionnaire measuring 'living well' with dementia that reflects the experience of people with mild-to-moderate dementia.
Nine people with dementia formed a co-production group. An initial series of workshops generated the format of the questionnaire and a longlist of items. Preliminary testing with 53 IDEAL cohort participants yielded a shortlist of items. These were tested with 136 IDEAL cohort participants during a further round of data collection and assessed for reliability and validity. The co-production group contributed to decisions throughout and agreed the final version.
An initial list of 230 items was reduced to 41 for initial testing, 12 for full testing, and 10 for the final version. The 10-item version had good internal consistency and test-retest reliability, and a single factor structure. Analyses showed significant large positive correlations with scores on measures of quality of life, well-being, and satisfaction with life, and expected patterns of association including a significant large negative association with depression scores and no association with cognitive test scores.
The co-produced My Life Questionnaire is an accessible and valid measure of 'living well' with dementia suitable for use in a range of contexts.This work was supported by the Economic and Social Research Council, National Institute for Health and Care Research (ES/L001853/2), and Alzheimer’s Society (348, AS-PR2-16-001)
Mobile Money, Child Labour and School Enrolment
Get PDFYesThis paper analyses the impact of household adoption of mobile money services on child labour and schooling in Tanzania. The paper uses data drawn from the Tanzania National Panel Surveys (TNPS), for the survey periods as follows: 2008/09, 2010/11, 2012/13, and 2014/15. The TNPS are national representative surveys conducted by the National Bureau of Statistics of Tanzania in collaboration with the World Bank Living Standards Measurement Study-Integrated Surveys on Agriculture (LMSA-ISA). The surveys collect detailed information on individual, household, and community-level characteristics. The panel nature of the TNPS allows for the same households to be interviewed over time. The study uses a difference-in-differences approach, and instrumental variables strategy to investigate the nexus between mobile money adoption and child labour and school enrolment in Tanzania. The findings of this study reveal a positive and significant effect of mobile money adoption on school enrolment, but a negative effect on children’s labour market activities. Moreover, the study identifies heterogenous impacts across child’s gender and age; and remittances receipt and education expenditure are the potential pathways through which mobile money adoption affects child labour and school enrolment. Overall, the results suggest that policies that enhance financial inclusion such as the introduction of mobile money can be effective in improving child’s school enrolment and a decline in the incidence of child labour
Self-efficacy and smoking cessation: A mixed method study among adult smokers in Fiji
Get PDFYesSmokers usually lack confidence to quit smoking due to previous unsuccessful attempts. This study aimed to assess self-efficacy and quitting smoking among current adult smokers in Suva, Fiji.
Methods: This study applied a mixed method design among current adult smokers who attended three randomly selected healthcare centers in Suva, Fiji between 1st May to 31st July 2020. A self-administered questionnaire was used to collect quantitative information on smoking and smoking cessation, self-efficacy, and stage of smoking. A semi-structured, open-ended questionnaire was used to guide the interviews. Qualitative data was transcribed and thematic analysis was applied to identify the common themes.
Results: Four hundred sixty-four smokers participated in the quantitative study, with a mean age of 32.7 (SD=12.1). Only 16.6% of participants were at the stage of “Preparation” and 4.95% of them were at the stage of “Action”, according to the stage of change model. Majority of participants (43.1%) had low self-efficacy to quit smoking. Thirty-five smokers participated in in-depth interviews, with majority (48.57%) in the age group of 18-24. Two themes were identified including “Determinants of self-efficacy” and “Factors affecting quit smoking”.
Conclusions: This study showed that adult smokers had low confidence to quit smoking. Developing a tailored intervention using models such as Transtheoretical Model (TTM) and stage of change may help smokers to quit smoking in Fiji.This project was funded by the Fiji National University grant
Reframing 'Place Leadership': An analysis of Leadership in responding to the wicked issue of county lines and criminality within a context of post pandemic public health policing
No full textNoThe chapter explores a practical approach to place leadership within what is increasingly acknowledged as a wicked problem. County lines and drug trafficking take place within complicated landscapes as multi-agency leaders, including police leaders, develop innovative solutions based on dialogue and relational approaches to this crucial wicked issue. Recent evidence on the scale of vulnerable individuals and groups inhabiting so called ‘left behind’ places provides testament to this 21st Century social policy problem (Addidle and Liddle, 2020). The many competing and contradictory conceptualisations of the phenomena of vulnerability leave place leaders with dilemmas on how to prioritise, operationalise and respond to such placed-based problems (Addidle and Liddle, 2020). Extant literature on place leadership remains largely at the economic level of analysis and based on growth models, but public leadership literature is more extensive and recent work has added to our understanding of the social contexts of place leadership within the public realm. Our key aim in this chapter is to add theoretical, empirical and policy insights to existing understandings, with a specific focus on crime and county lines
Self-sensing ultra-high performance concrete: A review
Get PDFYesUltra-high performance concrete (UHPC) is an innovative cementitious composite, that has been widely applied in numerous structural projects because of its superior mechanical properties and durability. However, ensuring the safety of UHPC structures necessitates an urgent need for technology to continuously monitor and evaluate their condition during their extended periods of service. Self-sensing ultra-high performance concrete (SSUHPC) extends the functionality of UHPC system by integrating conductive fillers into the UHPC matrix, allowing it to address above demands with great potential and superiority. By measuring and analyzing the relationship between fraction change in resistivity (FCR) and external stimulates (force, stress, strain), SSUHPC can effectively monitor the crack initiation and propagation as well as damage events in UHPC structures, thus offering a promising pathway for structural health monitoring (SHM). Research on SSUHPC has attracted substantial interests from both academic and engineering practitioners in recent years, this paper aims to provide a comprehensive review on the state of the art of SSUHPC. It offers a detailed overview of material composition, mechanical properties and self-sensing capabilities, and the underlying mechanisms involved of SSUHPC with various functional fillers. Furthermore, based on the recent advancements in SSUHPC technology, the paper concludes that SSUHPC has superior self-sensing performance under tensile load but poor self-sensing performance under compressive load. The mechanical and self-sensing properties of UHPC are substantially dependent on the type and dosage of functional fillers. In addition, the practical engineering SHM application of SSUHPC, particularly in the context of large-scale structure, is met with certain challenges, such as environment effects on the response of SSUHPC. Therefore, it still requires further extensive investigation and empirical validation to bridge the gap between laboratory research and real engineering application of SSUHPC
Development of ambient-cured geopolymer mortars with construction and demolition waste-based materials
Get PDFYesDegrading infrastructure and applications of structural demolition create
tremendous amounts of construction and demolition waste (CDW) all around
the world. To address this issue in an effective way, recycling CDW in a most appropriate
way has become a global concern in recent years. To this end, this study
focused on the valorization of CDW-based materials such as tile, bricks, glass,
and concrete in the development of geopolymer mortars. CDWs were first collected
from demolition zone and then subjected to crushing-milling operations. To
investigate the influence of slag (S) addition to the mixtures, 20% S substituted
mixture designs were also made. Fine recycled concrete aggregates (FRCA) obtained
from crushing and sieving of the waste concrete were used as the aggregate.
A series of mixtures were designed using different proportions of three distinct
alkali activators such as sodium hydroxide (NaOH), sodium silicate (Na2SiO3),
and calcium hydroxide (CH; Ca(OH)2). To improve their applicability, the mixtures
were left to cure at room temperature rather than the heat curing which
is frequently applied in the literature. After 28 days ambient curing, the 100%
CDW-based geopolymer mortar activated with three different activators reached
a compressive strength of 31.6 MPa, whereas the 20% S substituted geopolymer
mortar showed a 51.9 MPa compressive strength. While the geopolymer mortars
activated with only NaOH exhibited poor performance, it was found that the
use of Na2SiO3 and CH improved the mechanical performance. Main geopolymerization
products were related to NASH (Sodium alumino-silicate hydrate),
CASH (Calcium alumino-silicate hydrate), and C(N)ASH gel formations. Results
demonstrated that mixed CDWs can be employed in the manufacturing
geopolymers, making them potential alternatives to Portland cement (PC)-based
systems by being eco-friendly, energy-efficient, and comparable in compressive
strength.European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 894100
Mandatory CSR disclosure, institutional ownership and firm value: Evidence from China
Get PDFYesThis study aims to contribute to the relevant accounting, corporate gover-nance, and corporate social responsibility (CSR) literature by examining thevalue relevance of mandatory CSR disclosures in China. Using a difference-in-differences (DID) research design and a sample based on propensity scorematching (PSM) over the period from 2003 to 2020, our findings suggest thatmandatory CSR disclosures are negatively associated with firm' values. We alsofind that firms with a high level of institutional ownership and leverage experi-ence a relatively lower drop in firms' values as a result of the mandatory CSRdisclosures. These findings remain robust to alternative sampling design, use of market to book value as an alternative measure of firms' market-based performance, and a parallel test to validate our DID analysis. Our findings have useful implications for managers, regulators, policy makers and other stakeholders
Exploring Radio Frequency Techniques for Bone Fracture Detection: A Comprehensive Review of Low Frequency and Microwave Approaches
Get PDFYesThis comprehensive review paper examines bone fracture detection techniques based on time-domain low-frequency and microwave radiofrequency (RF). Early and accurate diagnosis of bone fractures remains critical in healthcare, as it can significantly improve patient outcomes. This review focuses on the potential of low-frequency and microwave RF methods, particularly their combination and application of time-domain analysis for enhanced fracture detection. We begin by providing an overview of the fundamental concepts of RF techniques and then by examining biological tissues' dielectric properties. We then compare the advantages and limitations of various bone fracture detection techniques, such as low-frequency RF methods, microwave RF methods, ultrasonography, X-ray, and CT scans. The discussion then shifts to hybrid approaches that combine low-frequency and microwave techniques, emphasising the advantages of such combinations in fracture detection. Machine learning techniques, their applications in bone fracture detection, and the role of time-domain analysis in hybrid approaches are also investigated.
Finally, we examine the accuracy and reliability of simulated models for bone fracture detection. We discuss recent advancements and future directions, such as novel sensor technologies, improved signal processing techniques, integration with medical imaging modalities, and personalised fracture detection approaches. This review aims to comprehensively understand the landscape and future potential of time-domain analysis in low-frequency and microwave RF techniques for bone fracture detection.EU Horizon Europe H2020-MSCA-RISE-2022-2027 (ID: 101086492) and H2020-MSCA-RISE-2019-2024 (ID 872878), Marie Skłodowska-Curie, Research and Innovation Staff Exchange (RISE), and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/ X039366/1
Characterization and life cycle assessment of geopolymer mortars with masonry units and recycled concrete aggregates assorted from construction and demolition waste
Get PDFYesDeveloping a fast, cost-effective, eco-friendly solution to recycle large amounts of construction and demolition waste (CDW) generated from construction industry-related activities and natural disasters is crucial. The present investigation aims to offer a solution for repurposing CDW into building materials suitable for accelerated construction and housing in developing countries and disaster-prone areas. Feasibility of recycled concrete aggregate (RCA) inclusion in geopolymer mortars constituted entirely from CDW (masonry elements) was investigated via an environmental impact-oriented approach by addressing the composition related key parameters. Mechanical performance was evaluated through compressive strength tests, and scanning electron microscope (SEM) imaging with line mapping analyses were carried out to monitor the interfacial transition zone (ITZ) properties. To investigate the environmental impacts of the geopolymer mortars and highlight the advantages over Portland cement-based mortars, a cradle-to-gate life cycle assessment (LCA) was performed. Findings revealed that roof tile (RT)-based geopolymer mortars mainly exhibited better strength performance due to their finer particle size. Mixtures activated with 15 M NaOH solution and cured at 105 °C achieved an average compressive strength above 55 MPa. RCA size was the most influential parameter on compressive strength, and a smaller maximum RCA size significantly increased the compressive strength. Microstructural analyses showed that the ITZ around smaller RCAs was relatively thinner, resulting in better compressive strength results. LCA proved that CDW-based geopolymer mortars provide the same compressive strength with around 60% less CO2 emissions and similar energy consumption compared to Portland cement-based mortars.European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 894100. The authors also wish to acknowledge the support of the Scientific and Technical Research Council of Turkey (TUBITAK) provided under project: 117M44