113 research outputs found

    Spatial Arbitrage Through Bidirectional Electric Vehicle Charging with Delivery Fleets

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    The adoption of electric vehicles (EVs), including electric taxis and buses, as a mode of transportation, is rapidly increasing in cities. In addition to providing economic and environmental benefits, these fleets can potentially participate in the energy arbitrage market by leveraging their mobile energy storage capabilities. This presents an opportunity for EV owners to contribute to a more sustainable and efficient energy system while also reducing their operational costs. The present study introduces deterministic and single-stage stochastic optimization frameworks that aim to maximize revenue by optimizing the charging, discharging, and travel of a fleet of electric vehicles in the context of uncertainty surrounding both spatial and temporal energy prices. The simulations are performed on a fleet of electric delivery trucks, which have to make deliveries to certain locations on specific dates. The findings indicate the promising potential of bidirectional electric vehicle charging as a mobile grid asset. However, it is important to note that significant revenue is only realized in scenarios where there is substantial variation in prices between different areas, and when these price variations can be accurately forecasted with a high level of confidence

    Convolutional Neural Network for Stereotypical Motor Movement Detection in Autism

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    Autism Spectrum Disorders (ASDs) are often associated with specific atypical postural or motor behaviors, of which Stereotypical Motor Movements (SMMs) have a specific visibility. While the identification and the quantification of SMM patterns remain complex, its automation would provide support to accurate tuning of the intervention in the therapy of autism. Therefore, it is essential to develop automatic SMM detection systems in a real world setting, taking care of strong inter-subject and intra-subject variability. Wireless accelerometer sensing technology can provide a valid infrastructure for real-time SMM detection, however such variability remains a problem also for machine learning methods, in particular whenever handcrafted features extracted from accelerometer signal are considered. Here, we propose to employ the deep learning paradigm in order to learn discriminating features from multi-sensor accelerometer signals. Our results provide preliminary evidence that feature learning and transfer learning embedded in the deep architecture achieve higher accurate SMM detectors in longitudinal scenarios.Comment: Presented at 5th NIPS Workshop on Machine Learning and Interpretation in Neuroimaging (MLINI), 2015, (http://arxiv.org/html/1605.04435), Report-no: MLINI/2015/1

    Nursing errors and effect on health care: Perception of risk factors from view of nurse in Qazvin

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    Background and aims: In order to plan for preventing and decreasing the rate of nursing errors, understanding of nurse’s perception of nursing errors could be very helpful. This study was thus designed to examine the critical care nurses perception of nursing errors from view point of critical care nurses. Methods: This study was conducted in 9 hospitals in Qazvin province located in north of Iran. Using convenience sampling, all registered nurses who worked in critical care units were invited to participate in the study. Data were collected between January and March 2015 with using “predisposing factors of nursing errors questionnaire”. Results: Of 379 nurses participated in this study, 77.8 (N= 213) were women. The mean age of participants was 34±2.2 years and mean years of experience was 8.1±1.5 years. Totally, from view of nurses, most and lowest common cusecs of nursing errors were related to “management aspect” and “Team coordination” items respectively. Conclusion: Nursing educational systems should pay more attention to nurses’ perception to nursing errors and may consider their view during planning and education towards decreasing nursing errors in critical care setting

    Physiological and Fluorescence Reaction of Four Rice Genotypes to Exogenous Application of IAA and Kinetin under Drought Stress

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    To assess the effects of IAA and Kinetin plant growth regulators in order to improve the drought tolerance in rice seedlings (Oryza sativa L.), a factorial experiment was carried out based on complete randomized design with three replications. The experimental factors included different rice genotypes [‘Gharib’, ‘Khazar’, ‘Sepidrood’ and ‘IR83750 -131-1’ (‘IR83750’ )], drought stress from 1 to 4 code of the Vergara coding system and control (normal irrigation) and growth regulators in three levels (IAA and Kinetin through foliar spraying and non-application as control). The results indicated, under normal irrigation condition together with IAA application, ‘IR83750’ rice had the highest number of tillers and leaf greenness, with mean of 18.27 and 49.46, respectively. The highest amount of leaf relative water content) 95.11 percent) was related to ‘Sepidrood’. Under drought stress condition, the highest electrolyte leakage (36.59 percent) was observed in ‘Gharib’. In drought condition, the highest leaf drying score was related to ‘Gharib’ in both years, but the highest score of leaf rolling index (9) was observed in ‘Gharib’ and ‘Khazar’. The present findings showed that drought stress had harmful effects in all examined genotypes and the impact in susceptible genotypes (‘Gharib’ and ‘Khazar’) was more than ‘IR83750’ and ‘Sepidrood’. Application of growth regulators (IAA and Kin) improved conditions for the growth of all genotypes. Therefore, using the tolerant genotypes along with growth regulators can improve the rice growth traits

    Development and Validation of a Comprehensive Tool for Assessing Postgraduate Students' Oral Presentations

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    Introduction: The aim of this study was to develop an oral presentations assessment tool for postgraduate students' oral presentations. Methods: First, a literature review and the ideas of 319 experienced professors were used to identify dimensions and potential items. Then the psychometric properties of the preliminary tool were measured using face and content validity, inter-rater agreement and test-retest reliability. Results: The four dimensions of the developed tool were subject knowledge, delivery, content and organization, and ergonomics. Mean content validity index and content validity ratio scores were 0.93 and 0.76, respectively. Spearman's rank correlation coefficient for the two evaluation periods was 0.92. The intra-class correlation coefficient was 0.78. Conclusion: In this study, important cognitive factors in oral presentations in the form of ergonomic dimensions were included for the first time, as part of a comprehensive tool. The developed tool has appropriate psychometric properties and could be used as a valid and applicable instrument to assess post-graduate students' oral presentations

    Seafarers’ mental health status and life satisfaction: Structural equation model

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    Background: A variety of factors influence seafarers' health. Such factors might affect their satisfaction with life. Aims: To examine the relationships between seafarers' mental health status and satisfaction with life by using a structural equation method. Methods: In this survey, 470 seafarers were selected via convenience sampling method from two shipping companies. Validated questionnaires including Satisfaction with Life Scale (SWLS), generalized anxiety disorder-7 (GAD-7), Post-traumatic Stress Disorder-8 (PTSD-8), Patient Health Questionnaire-9 (PHQ-9), General Health Questionnaire-12 (GHQ-12), Perceived Health status and Depression-Anxiety-Stress scale-21 (DASS-21) were used to assess different aspects of well-being and life satisfaction. The stratified path analysis method was applied to analyze the data. Results: 439 seafarers (200 officers and 237 non-officers) with a mean age of 34.5 (SD: 8.05) participated in the current study. The GHQ score directly affected satisfaction with life in both officers (β = 0.35) and non-officers (β = 0.40). Also, perceived health status directly and indirectly affected satisfaction with life among officers (β = 0.19) and non-officers (β = 0.06). While officers working days per month indirectly impacted satisfaction with life through the general anxiety disorder, perceived health status, depression, anxiety, stress and current mental health. In non-officers, generalized anxiety disorder had the most potent indirect effects on satisfaction with life through perceived health status and current mental health. Conclusion: Perceived health status, directly and indirectly, affected seafarers' satisfaction with life. Measures should be taken in order to improve seafarers' perceived health status and its effects on satisfaction with life

    Post-traumatic stress disorder and mental health assessment of seafarers working on ocean-going vessels during the COVID-19 pandemic

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    Background There are increasing concerns about mental health consequences of the COVID-19 pandemic among seafarers. This study aims to assess the effects of the current global health pandemic on life satisfaction and adverse psychological outcomes among seafarers. Methods In this cross-sectional study, 470 multinational seafarers working on board ships of two international shipping companies were assessed. Mental health outcomes were assessed by the general anxiety disorder (GAD-7) questionnaire, post-traumatic stress disorder (PTSD-8) questionnaire, and patient health questionnaire (PHQ-9) depressive severity score. Multivariate logistic regression was used to determine the association of demographic and work-related variables with mental health outcomes. Results Overall, 439 out of 470 invited seafarers with a mean age of 34.5 (SD: 8.05) years participated in this study (participation rate: 93.4%). The prevalence of anxiety, depressive, and post-traumatic stress symptoms was 12.4, 14.1, and 37.3%, respectively. In the multivariate model, the current vessel’s signing duration was directly associated with the odds of depressive and intrusion symptoms. Moreover, the duration of work per week was inversely associated with hyper-vigilance and avoidance. Also, non-officers, compared to officers, experienced significantly lower anxiety and depressive symptoms, hyper-vigilance, and avoidance. Conclusion The present study revealed a high prevalence of mental health problems among seafarers during the COVID-19 pandemic. We recommend that more evidence is generated regarding psychosocial health issues for this vulnerable occupation
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