228 research outputs found

    A Super Industrial Application of PSGraph

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    The ClawZ toolset has been successful in verifying that Ada code is correctly generated from Simulink models in an industrial setting, using the Z notation. D-RisQ is now extending this technique to new domains of the C programming language, which requires changes to their highly complex proof technique. In this paper, we present initial results in the technology transfer of the graphical PSGraph language to support this extension, and show feasibility of PSGraph for industrial use with strong maintainability requirements

    Mining State-Based Models from Proof Corpora

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    Interactive theorem provers have been used extensively to reason about various software/hardware systems and mathematical theorems. The key challenge when using an interactive prover is finding a suitable sequence of proof steps that will lead to a successful proof requires a significant amount of human intervention. This paper presents an automated technique that takes as input examples of successful proofs and infers an Extended Finite State Machine as output. This can in turn be used to generate proofs of new conjectures. Our preliminary experiments show that the inferred models are generally accurate (contain few false-positive sequences) and that representing existing proofs in such a way can be very useful when guiding new ones.Comment: To Appear at Conferences on Intelligent Computer Mathematics 201

    Male escorts’ and male clients’ sexual behavior during their last commercial sexual encounter: Comparing and contrasting findings from two online studies

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    Much of what is known about commercial sexual encounters between men is based on data gathered from escorts. With few exceptions, studies have not compared male clients’ reports of behavior during commercial sexual encounters with male escorts’. The present study draws from two datasets, a 2012 survey of clients (n = 495) and a 2013 survey of escorts (n = 387)—both used virtually identical measures of sexual behavior during the most recent commercial sexual encounter. For clients and escorts, the majority eschewed having sex without a condom, and kissing and oral sex were among the most common behaviors reported. Using logistic regression, both samples were compared across 15 sexual behaviors, finding significant differences in six—the escort sample had greater odds of reporting their last commercial sexual encounter involved watching the client masturbate, viewing porn, role play (dad/son, dominant/submissive), and having prior sexual experience with their commercial partner. The escort sample had lower odds of reporting that the client watched the escort masturbate, and being told partner’s HIV status. In multivariable modeling, both samples did not significantly differ in reports of condomless anal sex. Male-male commercial sexual encounters appear to involve a wide range of sexual behaviors, many of which convey low-to-no risk of HIV transmission

    Semi-Automated Design Space Exploration for Formal Modelling

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    Refinement based formal methods allow the modelling of systems through incremental steps via abstraction. Discovering the right levels of abstraction, formulating correct and meaningful invariants, and analysing faulty models are some of the challenges faced when using this technique. We propose Design Space Exploration that aims to assist a designer by automatically providing high-level modelling guidance

    Patient-reported outcome measures for cancer caregivers: a systematic review

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    Purpose Informal caregivers provide invaluable help and support to people with cancer. As treatments extend survival and the potential burdens on carers increase, there is a need to assess the impact of the role. This systematic review identified instruments that measure the impact of caregiving, evaluated their psychometric performance specifically in cancer and appraised the content. Methods A 2-stage search strategy was employed to: 1. identify instruments that measure the impact of caregiving, 2. run individual searches on each measure to identify publications evaluating psychometric performance in the target population. Searches were conducted in Medline, Embase, CINAHL and Psychinfo and restricted to English for instrument used and article language. Psychometric performance was evaluated for content and construct validity, internal consistency, test-retest reliability, precision, responsiveness and acceptability. Individual scale items were extracted and systematically categorised into conceptual domains. Results 10 papers were included reporting on the psychometric properties of 8 measures. Although construct validity and internal consistency were most frequently evaluated, no study comprehensively evaluated all relevant properties. Few studies met our inclusion criteria so it was not possible to consider the psychometric performance of the measures across a group of studies. Content analysis resulted in 16 domains with 5 overarching themes: lifestyle disruption; wellbeing; health of the caregiver; managing the situation and relationships. Conclusions Few measures of caregiver impact have been subject to psychometric evaluation in cancer caregivers. Those that have do not capture well changes in roles and responsibilities within the family and career, indicating the need for a new instrument

    Household factors and the risk of severe COVID-like illness early in the U.S. pandemic

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    Objective To investigate the role of children in the home and household crowding as risk factors for severe COVID-19 disease. Methods We used interview data from 6,831 U.S. adults screened for the Communities, Households and SARS/CoV-2 Epidemiology (CHASING) COVID Cohort Study in April 2020. Results In logistic regression models, the adjusted odds ratio [aOR] of hospitalization due to COVID-19 for having (versus not having) children in the home was 10.5 (95% CI:5.7–19.1) among study participants living in multi-unit dwellings and 2.2 (95% CI:1.2–6.5) among those living in single unit dwellings. Among participants living in multi-unit dwellings, the aOR for COVID-19 hospitalization among participants with more than 4 persons in their household (versus 1 person) was 2.5 (95% CI:1.0–6.1), and 0.8 (95% CI:0.15–4.1) among those living in single unit dwellings. Conclusion Early in the US SARS-CoV-2 pandemic, certain household exposures likely increased the risk of both SARS-CoV-2 acquisition and the risk of severe COVID-19 disease

    A European study on alcohol and drug use among young drivers : The TEND by night study design and methodology

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    Background. Young individuals are the age group with the highest risk of car accidents. One of main explanations relies on the use of psychoactive substances (alcohol, illegal and medicinal drugs), which are known to be major risk factors of road accidents, and whose consumption is almost universally more common among younger drivers. Although the correlation between psychoactive substances use and decrease in driving performance has been established in controlled experimental or laboratory settings, few studies were conducted in naturalistic circumstances. The TEND by Night project has been designed to evaluate the relationship between driving performance and psychoactive substances assumption in young drivers enrolled at typical places of consumption. Methods/Design. The TEND by Night project, endorsed by the European Commission, is a multidisciplinary, multi-centric, cross-sectional study conducted in six European countries (Italy, Belgium/Netherlands, Bulgaria, Spain, Poland and Latvia). The study population consists of 5000 young drivers aged 16-34 years, attending recreational sites during weekend nights. The intervention is based on the portal survey technique and includes several steps at the entrance and exit of selected sites, including the administration of semi-structured questionnaires, breath alcohol test, several drug assumption test, and measurement of the reaction time using a driving simulator. The main outcome is the difference in reaction time between the entrance and exit of the recreation site, and its correlation with psychoactive substances use. As a secondary outcome it will be explored the relationship between reaction time difference and the amount of consumption of each substance. All analyses will be multivariate. Discussion. The project methodology should provide some relevant advantages over traditional survey systems. The main strengths of the study include the large and multicentric sample, the objective measurement of substance assumption (which is typically self-reported), the application of a portal survey technique and the simultaneous evaluation of several psychoactive substances.publishersversionPeer reviewe

    Going the Distance: Locative Dating Technology and Queer Male Practice-Based Identities

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    Hybridisation of digital and physical space is now a reality for geographies of sexualities in the digital age. ‘This chapter builds on such an understanding by exploring how digital–physical hybridisation mediated by locative dating apps can shape queer male ‘practice-based’ identities, and how these typologies in turn inform physical queer encounters. Drawing from a qualitative research project with men who have sex with men (MSM), I examine the impact of online connection on different ‘routes’ to physical meeting. I argue that certain modes of behaviour help to identify a range of practice-based identities, implicitly linked to different forms of hybridisation. Three typologies exemplify practice-based identities: the ‘Embracer’, the ‘Time-waster’ and the ‘Minimalist’. These fluid typologies overlap and are even evident within a single identity across time, depending on personal motivation, the ‘market’ of available online matches, and app genre. Such typologies demonstrate the range of user engagement that becomes bound up in, and mediated by, the digital and physical hybridisation enabled by popular mobile media platforms. The development of practice-based identities can be extrapolated beyond thinking about online and offline spaces to new questions about future sexualities, identities and digital geographies
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