262,822 research outputs found
A step towards the live identification of pipe obstructions with the use of passive acoustic emission and supervised machine learning
No full textA single passive acoustic emission sensor was used to collect signals coming from an obstructed pipe in a water recirculation system. Four geometrically different obstructions were investigated. The flow field of water around each obstruction was visualised with the use of 2D particle image velocimetry (PIV) to identify the different flow features. In parallel, the acoustic emission signals were acquired by locating a piezoelectric sensor on the outer wall of the pipe at the tip of the obstruction. The acoustic emission signals were then pre-processed and the frequency domain was extracted for 100 recordings in each case. Signals were processed further by using principle component analysis and a matrix is created for supervised machine learning algorithms. This methodology was applied over a range of four flow rates, all in fully developed turbulent flow. Results showed that different obstructions generated different acoustic signals and flow fields, which reflected the different flow fields observed with PIV. The average velocity and amplitude of the acoustic signals increased in magnitude with increasing flow rate. The machine-learning algorithm with highest prediction values was quadratic support-vector machine with predictions in the area of 95% accuracy or above. This makes the combination of machine learning and a single passive acoustic sensor a viable option to predict pipe obstructions and the type of obstruction. This may lead to a useful application for urban water supply or sewage systems as well as agricultural practice for field irrigation or the detection of nozzle blockages
Valutazione del funzionamento psicosociale di pazienti in terapia con paliperidone. Confronto con aloperidolo nel "real world".
No full textAims: endpoints of psychotic patients treatments changed a lot in the last years, just as the way of evaluate their efficacy. This happened especially because of the introduction of new psychotropic drugs, able to improve many aspects concerning with psychotic disease. From the ’90s was clear that an improvement only in symptoms could not be identified with a clinical success; actually, interpersonal abilities, quality of life and psychosocial functioning were indicated as the real endpoints of a psychiatric treatment. Paliperidone is an antipsychotic recently introduced in the market. It is a second generation antipsychotic. Many first generation antipsychotics are still widely used in clinical practice, especially haloperidol. A comparison between these two drugs, in terms of social functioning, has been short investigated. First aim of the study is the comparison between patients treated with paliperidone and patients treated with haloperidol, evaluating their social functioning with PSP (Personal and Social Performace Scale). The second aim concerns with symptomatic improvement, evaluated with PANSS (Positive and Negative Syndrome Scale).
Methods: This is a study related to patients from Operative Unity of Psychiatry I and II of Varese. Inclusion methods are a diagnosis of Schizophrenia or other Psychotic Disorders according to DSM IV-TR, and the beginning of a treatment with paliperidone (3-12 mg/day) or haloperidol (2-10 mg/day). Personal data and rating scales scores are marked. Symptomatic recrudescence leading to a new psychiatric hospital admission must not be present in the last three months. Patients are followed up for 6 months.
Risults: 34 patients have been investigated for 6 months (17 treated with paliperidone, 17 treated with haloperidol). The general trend is concerning with a psychosocial and a clinical improvement, both with paliperidone and haloperidol, but no statistically significant difference was found.
Conclusions: Treatment with paliperidone didn’t show a better outcome than haloperidol about psychosocial functioning and symptomatic improvement in psychotic patients
Rates of Time Preferences for Saving Lives in the Hazardous Waste Site Context
No full textWhat is the rate at which people discount future lives saved? The answer to this question has important implications when comparing policies on the grounds of cost per life saved, especially in the context of hazardous waste site remediation, where risk reductions may occur at different times, depending on the permanence of the remedy. We estimate this rate by asking a sample of Italian residents to choose between saving 100 lives now and X lives in T years, where both X and T are varied to the respondents. Assuming constant exponential discounting, the responses to these questions imply a rate of time preference for saving lives of 12%. There is little evidence that this rate is systematically associated with observable individual characteristics of the respondent. There is, however, strong evidence that it declines with the time horizon when the lives would be saved, ranging from 16% for T=10 to less than 4% for T³40. We fit a hyperbolic discount model, finding that it yields a similar value of the discount function for T=10 (the shortest horizon we used in the survey), and that it discounts the future less heavily than the regular exponential discounting model for longer time horizon. We apply our estimated discount functions to two alternate remedial plans for a heavily contaminated area in Italy, and find that—due to the high estimated discount rates—the less permanent solution is found to be more cost-effective.Value of a Statistical Life, Latent Risk Reductions, Individual Discount Rates, Rate of Time Preference for Saving Lives, Contaminated Sites, Remediation
Context and the VSL: Evidence from a Stated Preference Study in Italy and the Czech Republic
No full textWe report on the results of a survey based on conjoint choice experiments that was specifically designed to investigate the effect of context on the Value of a Statistical Life (VSL), an important input into the calculation of the mortality benefits of environmental policies that reduce premature mortality. We define “context” broadly to include i) the cause of death (respiratory illness, cancer, road traffic accident), ii) the beneficiary of the risk reduction (adult v. child), and iii) the mode of provision of the risk reduction (public program v. private good). The survey was conducted following similar protocols in Italy and the Czech Republic. When do not distinguish for the cause of death, child and adult VSL are not significantly different from one another in Italy, and the difference is weak in the Czech sample. When we distinguish for the cause of death, we find that child and adult VSLs are different at the 1% level for respiratory illnesses and road-traffic accidents, but do not differ for cancer risks. We find evidence of a “cancer premium” and a “public program premium.” In both countries, the marginal utility of income is about 20% lower among wealthier people, which makes the VSL about 20% higher among respondents with incomes above the sample average. The discount rate implicit in people‘s choices is effectively zero. We conclude that there is heterogeneity in the VSL, and that such heterogeneity is primarily driven by risk characteristics and mode of delivery of the risk reduction, rather than by individual characteristics of the respondent (e.g., income and education). For the most part, our results do not disagree with environmental policy analyses that use the same VSL for children and adults, and that apply a cancer premium.VSL, Conjoint Choice Experiments, Mortality Risk Reductions, Cost-benefit Analysis, Forced Choice Questions
La resistenza dei solai soggetti ad incendio: problemi di simulazione numerica campo termico
No full textWillingness to Pay for Mortality Risk Reductions: Does Latency Matter?
No full textUsing results from two contingent valuation surveys conducted in Canada and the U.S., we explore the effect of a latency period on willingness to pay (WTP) for reduced mortality risk using both structural and reduced form approaches. We find that delaying the time at which the risk reduction occurs by 10 to 30 years reduces WTP by more than half for respondents in both samples aged 40 to 60 years. Additionally, we estimate implicit discount rates equal to 8% for Canada and 4.5% for the U.S. – both well within the range established previously in the literature.Value of a statistical life, Mortality risks, Benefit-cost analyris
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