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Fault Detection of Wheelset Bearings through Vibration-Sound Fusion Data Based on Grey Wolf Optimizer and Support Vector Machine
Get PDFData Availability Statement: The data presented in this study are available on request from the corresponding author. The data are not publicly available due to commercial privacy.This study aims to detect faults in wheelset bearings by analyzing vibration-sound fusion data, proposing a novel method based on Grey Wolf Optimizer (GWO) and Support Vector Machine (SVM). Wheelset bearings play a vital role in transportation. However, malfunctions in the bearing might result in extensive periods of inactivity and maintenance, disrupting supply chains, increasing operational costs, and causing delays that affect both businesses and consumers. Fast fault identification is crucial for minimizing maintenance expenses. In this paper, we proposed a new integration of GWO for optimizing SVM hyperparameters, specifically tailored for handling sound-vibration signals in fault detection. We have developed a new fault detection method that efficiently processes fusion data and performs rapid analysis and prediction within 0.0027 milliseconds per data segment, achieving a test accuracy of 98.3%. Compared to the SVM and neural network models built in MATLAB, the proposed method demonstrates superior detection performance. Overall, the GWO-SVM-based method proposed in this study shows significant advantages in fault detection of wheelset bearing vibrations, providing an efficient and reliable solution that is expected to reduce maintenance costs and improve the operational efficiency and reliability of equipment.This work is partially supported by the Royal Society award (IEC\NSFC\223294)
Reducing Vulnerability to Exploitation of Nepali Migrant Domestic Workers
Get PDFA report deposited in Brunel figsharePolicy Context: In 2017, the government of Nepal issued a directive banning international emigration for domestic work, with the aim of protecting Nepali citizens from labour exploitation in the domestic work sector abroad. The ban has since been eased slightly, subject to preconditions including the establishment of Bilateral Labour Agreements (BLA) on domestic work, which are non-legally binding labour migration regulatory frameworks with each receiving country. Despite the ban, overseas employers continue to issue domestic work visas. The ban overlooks evidence of positive outcomes for Nepali domestic workers and leads to several unintended and damaging consequences.
Advice:To address the Nepali migrant domestic workers’ vulnerability to becoming stranded and exploited, the migration ban should be lifted, alongside initiating legally binding negotiations with countries employing these workers. Support mechanisms for domestic workers in host countries and reintegration processes for returnees in Nepal should be strengthened.Gerda Henkel Stiftun
Measurement of energy correlators inside jets and determination of the strong coupling αS(mZ)
Get PDFA preprint version of this article is available at arXiv:2402.13864v2 [hep-ex], https://arxiv.org/abs/2402.13864 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/SMP-22-015 (CMS Public Pages). Report number: CMS-SMP-22-015, CERN-EP-2024-010 .Energy correlators that describe energy-weighted distances between two or three particles in a hadronic jet are measured using an event sample of √ = 13 TeV proton-proton collisions collected by the CMS experiment and corresponding to an integrated luminosity of 36.3 fb^−1. The measured distributions are consistent with the trends in the simulation that reveal two key features of the strong interaction: confinement and asymptotic freedom. By comparing the ratio of the measured three- and two-particle energy correlator distributions with theoretical calculations that resum collinear emissions at approximate next-to-next-to-leading-logarithmic accuracy matched to a next-to-leading-order calculation, the strong coupling is determined at the boson mass: () = 0.1229+0.0040 −0.0050, the most precise () value obtained using jet substructure observables.SCOAP3
Cognitive and psychiatric symptom trajectories 2–3 years after hospital admission for COVID-19: a longitudinal, prospective cohort study in the UK
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The PHOSP-COVID protocol, consent form, definition and derivation of clinical characteristics and outcomes, training materials, regulatory documents, requests for data access, and other relevant study materials are available via the PHOSP-COVID website.Supplementary material is available online at: https://www.thelancet.com/cms/10.1016/S2215-0366(24)00214-1/attachment/7e690a57-1ab6-4295-8dd7-7cc2c44b2067/mmc1.pdf .Background: COVID-19 is known to be associated with increased risks of cognitive and psychiatric outcomes after the acute phase of disease. We aimed to assess whether these symptoms can emerge or persist more than 1 year after hospitalisation for COVID-19, to identify which early aspects of COVID-19 illness predict longer-term symptoms, and to establish how these symptoms relate to occupational functioning. Methods: The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study of adults (aged ≥18 years) who were hospitalised with a clinical diagnosis of COVID-19 at participating National Health Service hospitals across the UK. In the C-Fog study, a subset of PHOSP-COVID participants who consented to be recontacted for other research were invited to complete a computerised cognitive assessment and clinical scales between 2 years and 3 years after hospital admission. Participants completed eight cognitive tasks, covering eight cognitive domains, from the Cognitron battery, in addition to the 9-item Patient Health Questionnaire for depression, the Generalised Anxiety Disorder 7-item scale, the Functional Assessment of Chronic Illness Therapy Fatigue Scale, and the 20-item Cognitive Change Index (CCI-20) questionnaire to assess subjective cognitive decline. We evaluated how the absolute risks of symptoms evolved between follow-ups at 6 months, 12 months, and 2–3 years, and whether symptoms at 2–3 years were predicted by earlier aspects of COVID-19 illness. Participants completed an occupation change questionnaire to establish whether their occupation or working status had changed and, if so, why. We assessed which symptoms at 2–3 years were associated with occupation change. People with lived experience were involved in the study. Findings: 2469 PHOSP-COVID participants were invited to participate in the C-Fog study, and 475 participants (191 [40·2%] females and 284 [59·8%] males; mean age 58·26 [SD 11·13] years) who were discharged from one of 83 hospitals provided data at the 2–3-year follow-up. Participants had worse cognitive scores than would be expected on the basis of their sociodemographic characteristics across all cognitive domains tested (average score 0·71 SD below the mean [IQR 0·16–1·04]; p<0·0001). Most participants reported at least mild depression (263 [74·5%] of 353), anxiety (189 [53·5%] of 353), fatigue (220 [62·3%] of 353), or subjective cognitive decline (184 [52·1%] of 353), and more than a fifth reported severe depression (79 [22·4%] of 353), fatigue (87 [24·6%] of 353), or subjective cognitive decline (88 [24·9%] of 353). Depression, anxiety, and fatigue were worse at 2–3 years than at 6 months or 12 months, with evidence of both worsening of existing symptoms and emergence of new symptoms. Symptoms at 2–3 years were not predicted by the severity of acute COVID-19 illness, but were strongly predicted by the degree of recovery at 6 months (explaining 35·0–48·8% of the variance in anxiety, depression, fatigue, and subjective cognitive decline); by a biocognitive profile linking acutely raised D-dimer relative to C-reactive protein with subjective cognitive deficits at 6 months (explaining 7·0–17·2% of the variance in anxiety, depression, fatigue, and subjective cognitive decline); and by anxiety, depression, fatigue, and subjective cognitive deficit at 6 months. Objective cognitive deficits at 2–3 years were not predicted by any of the factors tested, except for cognitive deficits at 6 months, explaining 10·6% of their variance. 95 of 353 participants (26·9% [95% CI 22·6–31·8]) reported occupational change, with poor health being the most common reason for this change. Occupation change was strongly and specifically associated with objective cognitive deficits (odds ratio [OR] 1·51 [95% CI 1·04–2·22] for every SD decrease in overall cognitive score) and subjective cognitive decline (OR 1·54 [1·21–1·98] for every point increase in CCI-20). Interpretation: Psychiatric and cognitive symptoms appear to increase over the first 2–3 years post-hospitalisation due to both worsening of symptoms already present at 6 months and emergence of new symptoms. New symptoms occur mostly in people with other symptoms already present at 6 months. Early identification and management of symptoms might therefore be an effective strategy to prevent later onset of a complex syndrome. Occupation change is common and associated mainly with objective and subjective cognitive deficits. Interventions to promote cognitive recovery or to prevent cognitive decline are therefore needed to limit the functional and economic impacts of COVID-19. Funding: National Institute for Health and Care Research Oxford Health Biomedical Research Centre, Wolfson Foundation, MQ Mental Health Research, MRC-UK Research and Innovation, and National Institute for Health and Care Research.National Institute for Health and Care Research Oxford Health Biomedical Research Centre, Wolfson Foundation, MQ Mental Health Research, MRC-UK Research and Innovation, and National Institute for Health and Care Research
Uniaxial Compression Test and Numerical Study on the Mechanical Mechanism of Crack Exhibition and Propagation in Layered Rocks
Get PDFData Availability Statement: The datasets generated and/or analyzed during the current study are available from the corresponding author upon request.Layered rocks are widely distributed in mining and underground engineering. The evolution processes, such as crack initiation, development and penetration, inevitably occur due to stress changes. This study carried out an experiment and numerical simulation to explore the correspondence between crack distribution and bedding dip, and to reveal the mechanical mechanism of layered rock fracturing. The results show that the layered rock specimens with different bedding dips obtained different stress combinations under the same uniaxial compression conditions. There are a total of five types of stress combinations, including pure compression type, compression shear type, pure shear type, tension shear type, and pure tension type. The Mohr circle is effective in characterizing the relationship between the stress combinations and failure modes. The failure mode of layered rocks in the range of 0° to 150° is presented the variation features of “tensile failure → compression-shear failure → shear failure → tensile shear failure → tensile failure”. Furthermore, the combined distributions of dominant and secondary cracks are summarized into the penetrating mode, the exfoliation mode, the feather crack mode, and the associated mode in high-dip of layered marbles. This paper provides research ideas for stability monitoring and crack tracking of layered rock mass engineering.The authors give thanks for the financial support by the Jiangxi Provincial Natural Science Foundation (No. 20232ACB214007) and the National Natural Science Foundation of China (No. 41977219)
Engaging low-income families in education research: examining the challenges in Beijing and London
Get PDFThis comparative paper considers the similar challenges encountered in Beijing (China) and Greater London (England) when engaging low-income families in education research. Through semi-structured interviews with 10 parents/caregivers in Beijing and 13 parents in Greater London, we explored perceptions of the barriers to participation, the influence of identity on involvement, and ways to better enable their contribution to education research. We found that key barriers to research participation across both cohorts centred on practical issues of a lack of time and childcare support and a sense of the pointlessness of research. Despite these commonalities, subtle differences emerged in how these barriers were experienced in each context, influenced by local socio-cultural factors. We conclude by reflecting on the forms of support that would encourage and enable socio-economically disadvantaged parents/caregivers in different country contexts to take part in education research. Our findings contribute new, comparative knowledge to best practice approaches, highlighting specific policy interventions that could improve the diversity of research participation
The tools of external migration policy in EU member states
Get PDFNote: This article gives the views of the authors, not the position of EUROPP – European Politics and Policy or the London School of Economics. Featured image credit: Alessia Pierdomenico / Shutterstock.com .LSE European Politics and Policy Blog. External migration policies, in which states cooperate with third countries to help manage migration, are now increasingly common. Drawing on new research, Matilde Rosina and Iole Fontana identify the key tools used by EU member states to implement these policies. For more information, see the authors’ accompanying paper in the Journal of Common Market Studies (Fontana, I. and Rosina, M. (2024) ‘ The Tools of External Migration Policy in the EU Member States: The Case of Italy’. JCMS: Journal of Common Market Studies. https://doi.org/10.1111/jcms.13581
Atmospheric pollution in Chinese cities: trends and persistence
Get PDFJEL classification: C22;.Q53.This paper applies fractional integration to investigate the behaviour of various pollutants in seven Chinese cities. The objective is to establish if the series exhibit long memory and if time trends are statistically significant over the sample period going from January 2014 to November 2022. The results suggest that the steps recently taken by the Chinese authorities to reduce emissions and improve air quality have already had some effect: in most cases the air pollutant series are in the stationary range, with mean reversion occurring and shocks only having temporary effects, and there are significant downward trends indicating a decline over time in the degree of pollution in China. It is also interesting that in the most recent period, the Zero-Covid policy of the Chinese authorities has led to a further fall. On the whole, it would appear that the action plan adopted by the Chinese government is bringing the expected environmental benefits and therefore it is to be hoped that such policies will continue to be implemented and extended to improve air quality even further.Luis A. Gil-Alana also gratefully acknowledges financial support from the Grant PID2020-113691RB-I00 funded by MCIN/AEI/ 10.13039/501100011033, and from an internal Project from the Universidad Francisco de Vitoria
Pushing the envelope – How the genome interacts with the nuclear envelope in health and disease
No full textThe nuclear envelope has for long been considered more than just the physical border between the nucleoplasm and the cytoplasm, emerging as a crucial player in genome organisation and regulation within the 3D nucleus. Consequently, its study has become a valuable topic in the research of cancer, ageing and several other diseases where chromatin organisation is compromised. In this chapter, we will delve into its several sub-elements, such as the nuclear lamina, nuclear pore complexes and nuclear envelope proteins, and their diverse roles in nuclear function and maintenance. We will explore their functions beyond nuclear structure and transport focusing on their interactions with chromatin and their paramount influence in its organisation, regulation and expression at the nuclear periphery. Finally, we will outline how this chromatin organisation and regulation at the nuclear envelope is affected in diseases, including laminopathies, cancer, neurodegenerative diseases and during viral infections
Who can afford to dissent at work? The mediating effect of organizational socialization on the relationship between social capital and organizational dissent
Get PDFData availability statement: The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.Introduction: In today’s interconnected world, fostering a culture of constructive dissent within organizations is more important than ever. Our study sheds light on how social capital—our networks and relationships—affects employees’ ability to express dissent. This study aims to empirically examine whether organizational socialization has a mediating effect on the relationship between social capital and organizational dissent.
Methods: We utilized surveys to collect data from participants. Quantitative data was collected from 240 employees within the textile in Türkiye. We used structural equation modeling through SmartPLS to test four hypotheses.
Results: According to the results of the SEM, social capital positively affects organizational dissent. Similarly, social capital positively affects organizational socialization. The mediation level of organizational socialization is at the level of partial mediation on the relationship between social capital and organizational dissent. Based on the results, organizational socialization positively affects organizational dissent.
Discussion: We contribute to the literature by extending social capital research by illustrating that employees’ social relationships lead to organizational socialization and organizational dissent behavior at work. The results suggest that the ability of employees to show dissent behavior is conditioned by their social capital and mediated by organizational socialization. This research is particularly relevant in sectors with hierarchical structures, where encouraging voice and participation can lead to significant advancements.The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article
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