Automated fault tree learning from continuous-valued sensor data: a case study on domestic heaters

Many industrial sectors have been collecting big sensor data. With recent technologies for processing big data, companies can exploit this for automatic failure detection and prevention. We propose the first completely automated method for failure analysis, machine-learning fault trees from raw observational data with continuous variables. Our method scales well and is tested on a real-world, five-year dataset of domestic heater operations in The Netherlands, with 31 million unique heater-day readings, each containing 27 sensor and 11 failure variables. Our method builds on two previous procedures: the C4.5 decision-tree learning algorithm, and the LIFT fault tree learning algorithm from Boolean data. C4.5 pre-processes each continuous variable: it learns an optimal numerical threshold which distinguishes between faulty and normal operation of the top-level system. These thresholds discretise the variables, thus allowing LIFT to learn fault trees which model the root failure mechanisms of the system and are explainable. We obtain fault trees for the 11 failure variables, and evaluate them in two ways: quantitatively, with a significance score, and qualitatively, with domain specialists. Some of the fault trees learnt have almost maximum significance (above 0.95), while others have medium-to-low significance (around 0.30), reflecting the difficulty of learning from big, noisy, real-world sensor data. The domain specialists confirm that the fault trees model meaningful relationships among the variables.Comment: Preprint submitted to the International Journal of Prognostics and Health Management - March 202

Within- and between-year variation in the presence of individually marked Ruff <i>Calidris pugnax</i> at a stopover site during northward migration

Ruffs Calidris pugnax migrate from wintering areas in West-Africa and Europe tobreeding grounds in northern Eurasia, using stopover sites along the way. At onesuch stopover site in southwest Friesland (53°N, The Netherlands), we studiedvariation in the timing of individual stopover based on 6474 Ruffs colour-ringedin 2004–2012. 43% of males and 22% of females were recorded in the studyarea in March–May the years following marking. Minimal stopover duration ofreturning individuals showed substantial within-year heterogeneity. We distinguishedtwo classes: (1) ‘transient’ individuals were observed only on a singleday in the study area within a season (51% of observed males and 79% offemales), and (2) ‘staging’ individuals were observed on multiple days. Weobserved two seasonal peaks in the presence of transient Ruffs, typically coincidingwith the peak of arrival and departure of staging birds. Males known towinter in Europe were more likely to be observed in the study area and arrivedearlier than males of unknown winter origin (3.1 days and 3.7 days earlier fortransient and staging males, respectively), but departure was unrelated to winterorigin. Staging and transient females arrived later than males. Between-yearrepeatability of individual behaviour was low, and individuals did not significantlyadvance their arrival date over the course of years, in contrast with a pattern ofshifting arrival dates at the population level. The observation that a large proportionof Ruffs visit southwest Friesland for only a short stop suggests that manyindividuals rely on other sites for moulting and refuelling during spring migration.Resightings of marked individuals elsewhere in western Europe indicated thatthese sites are largely located between 51° and 54°N. Thus, during springmigration, Ruffs marked in southwest Friesland displayed high between- andwithin-individual variation in minimal stopover duration

Editorial: Can't get you out of my head: brain-body interactions in perseverative cognition

Perseverative cognition represents a prototypical example of how our internal thoughts can impact our psychological and physical health, as if we were facing an actual environmental stressor (Brosschot et al., 2006). The mechanisms involved—together with other emblematic examples like the placebo effect—provide clear evidence for brain-body interaction. This collection of articles presents recent advances in our understanding of perseverative cognition that have arisen from the integration of multidisciplinary approaches encompassing cognitive and clinical psychology, affective neuroscience, and autonomic physiology. These advances carry with them the promise of more effective treatments to mitigate the negative consequences of maladaptive perseverative cognition on health and well-being

A Network Study of Family Affect Systems in Daily Life

Adolescence is a time period characterized by extremes in affect and increasing prevalence of mental health problems. Prior studies have illustrated how affect states of adolescents are related to interactions with parents. However, it remains unclear how affect states among family triads, that is adolescents and their parents, are related in daily life. This study investigated affect state dynamics (happy, sad, relaxed, and irritated) of 60 family triads, including 60 adolescents (Mage = 15.92, 63.3% females), fathers and mothers (Mage = 49.16). The families participated in the RE-PAIR study, where they reported their affect states in four ecological momentary assessments per day for 14 days. First, we used multilevel vector-autoregressive network models to estimate affect dynamics across all families, and for each family individually. Resulting models elucidated how family affect states were related at the same moment, and over time. We identified relations from parents to adolescents and vice versa, while considering family variation in these relations. Second, we evaluated the statistical performance of the network model via a simulation study, varying the percentage missing data, the number of families, and the number of time points. We conclude with substantive and statistical recommendations for future research on family affect dynamics.</p

Associations between chronotypes and psychological vulnerability factors of depression

Chronotypes have been associated with psychopathology. The eveningness chronotype has been consistently linked with depressed states or depressive disorder, but the underlying mechanism remains unclear. Prior studies have shown associations between chronotype and personality traits that are linked to depression (e.g. neuroticism), but other psychological vulnerability factors have not been previously investigated in relation to chronotypes. The aim of this study was to examine the association between chronotypes, depression and psychological risk factors of depression (namely, cognitive reactivity and worry), in a large cohort of depressed patients and healthy individuals. We used data from the Netherlands Study of Depression and Anxiety (n = 1654), which includes 1227 clinically diagnosed individuals with a lifetime diagnosis of depression and 427 healthy controls. We assessed cognitive reactivity (Leiden Index of Depression Sensitivity-Revised) and trait worry (Penn State Worry Questionnaire). We controlled for sociodemographic factors as well as for insomnia and neuroticism. We found that the evening type is associated with higher cognitive reactivity scores, especially with increased rumination. Cognitive reactivity also mediated the relationship between chronotype and depression status, even when controlling for neuroticism and insomnia. Trait worry was not associated with chronotype. Our findings show that depressogenic cognitions are more prevalent in evening types and perhaps mediate the association between chronotype and depression. Further prospective research is needed to determine the timeline of the association. Nevertheless, results imply that targeting depressogenic cognitive processes, perhaps in combination with chronotherapeutic treatments, may be particularly useful in evening types

Versluis - worry postponement

Reducing worry and subjective health complaints: A randomized trial of an internet-delivered worry postponement intervention Anke Versluis, Bart Verkuil and Jos F. Brosschot British Journal of Health Psychology (2015) http://onlinelibrary.wiley.com/doi/10.1111/bjhp.12170/full Objectives. Several studies have shown that perseverative, worrisome thoughts are prospectively related to subjective health complaints (SHC) and that a short worry postponement intervention can decrease these complaints. As SHC and worry are prevalent and costly, we tested whether the intervention can be offered online to reduce these complaints in the general population. Design. Arandomized parallel-group trial was conducted with self-selected participants from the general population. Methods. Via the research website, 996 participants were instructed to register their worrying for 6 consecutive days. The intervention group was instructed to postpone worry to a special 30-min period in the early evening. The Subjective Health Complaints inventory, as administered before and after the intervention, and daily worry frequency and duration were considered the primary outcomes. Results. Three hundred and sixty-one participants completed the study. Contrary to our expectation, the registration group (n = 188) did not differ from the intervention group (n = 163) in SHC (eta-p = .000, CI [0.000–0.003]), or in worry frequency or duration. Nevertheless, the different worry parameters were moderately related to SHC (r between .238 and .340, p ? .001). Conclusions. In contrast to previous studies using pen-and-pencil versions of the worry postponement intervention, this study suggests that a direct online implementation was not effective in reducing SHC and worry. Overall, participants had high trait worry levels and reported difficulty with postponing worrying. Reducing SHC and worries via the Internet might require more elaborate interventions that better incorporate the advantages of delivering interventions online