Search results for " isola"

Fault detection for continuous-time switched systems under asynchronous switching

2013

In this chapter, the problem of FD for continuous-time switched systems under asynchronous switching is investigated. The designed FD filter is assumed to be asynchronous with the original systems. Attention is focused on designing a FD filter such that the estimation error between the residual and the fault is minimized in the sense of H ∞ norm. By employing piecewise Lyapunov function and ADT techniques, a sufficient condition for the existence of such a filter is exploited in terms of certain LMIs. Finally, an example is provided to illustrate the effectiveness of the proposed approach.

A Deep Learning Approach for Automated Fault Detection on Solar Modules Using Image Composites

2021

Aerial inspection of solar modules is becoming increasingly popular in automatizing operations and maintenance in large-scale photovoltaic power plants. Current practices are typically time-consuming as they make use of manual acquisitions and analysis of thousands of images to scan for faults and anomalies in the modules. In this paper, we explore and evaluate the use of computer vision and deep learning methods for automating the analysis of fault detection and classification in large scale photovoltaic module installations. We use convolutional neural networks to analyze thermal and visible color images acquired by cameras mounted on unmanned aerial vehicles. We generate composite images…

Critical Assessments of the Potential for Integrating Renewable Energy into Isolated Grids on Vietnamese Islands: The Case of the An-Binh Grid

2023

Renewable electricity for off-grid areas is widely seen as one of the top choices in supporting local economic development in most countries, and so is Vietnam. Over the years, many isolated networks using renewable energy sources have been deployed for off-grid areas in Vietnam. However, the use of these energy sources in Vietnam’s isolated networks is still facing many challenges due to its infancy here. The issues of reliability and vulnerability of these networks are not given the expected attention. Another challenge is that the issues of the operational security of these systems could also be negatively affected by the variable nature of renewable sources, including static and dynamic…

Prevalence and Psychosocial Correlates of Mental Health Outcomes Among Chinese College Students During the Coronavirus Disease (COVID-19) Pandemic.

2020

Objectives: To investigate the prevalence and risk factors for poor mental health of Chinese university students during the Corona Virus Disease 2019 (COVID-19) pandemic. Method: Chinese nation-wide on-line cross-sectional survey on university students, collected between February 12th and 17th, 2020. Primary outcome was prevalence of clinically-relevant posttraumatic stress disorder symptoms. Secondary outcomes on poor mental health included prevalence of clinically-relevant anxiety and depressive symptoms, while posttraumatic growth was considered as indicator of effective coping reaction. Results: Of 2,500 invited Chinese university students, 2,038 completed the survey. Prevalence of clin…

Psychosocial and behavioural factors in heart transplant candidates--an overview.

2007

Mortality among heart transplant (HTX) candidates remains high. This review of the literature shows that psychosocial characteristics like depression, social isolation and coping strategies contribute to morbidity and mortality in heart failure (HF) patients, and may also be relevant to the prognosis of HTX candidates. Based on the research to date, physical activity favourably affects subjective and objective parameters not only in HF patients, but also in HTX candidates. Depression is prevalent among HTX candidates, especially in ischaemic patients, and seems to be related to earlier transplantation. Findings on the effects of depression on pretransplant mortality are conflicting. Not muc…

COVID-19 Confinement and Health Risk Behaviors in Spain

2020

The World Health Organization (WHO) has declared a world pandemic due to COVID-19. In response, most affected countries have enacted measures involving compulsory confinement and restrictions on free movement, which likely influence citizens' lifestyles. This study investigates changes in health risk behaviors (HRBs) with duration of confinement. An online cross-sectional survey served to collect data about the Spanish adult population regarding health behaviors during the first 3 weeks of confinement. A large sample of participants (N = 2,741) (51.8% women; mean age 34.2 years [SD 13.0]) from all Spanish regions completed the survey. Binomial logistic regressions adjusted for socioeconomic…

Online gaming and prolonged self-isolation: evidence from Italian gamers during the COVID-19 outbreak

2021

Objective: The self-isolation measures employed during the COVID-19 pandemic made it difficult for basic needs to be met, thus increasing emotional distress. It has been suggested that socially meaningful online gaming buffered emotional distress during the lockdown. This study aimed to test the protective effect of online gaming during the lockdown and to investigate the differences between highly involved gamers (those who play videogames intensely without adverse consequences) and problematic gamers in this regard. Method: Capitalizing on a data collection that started before the pandemic, we adopted a cross-sectional between-groups study design in which gaming patterns, gaming-related v…

Analysis, design, and evaluation of a high frequency inductor to reduce manufacturing cost, and improve the efficiency of a PV inverter

2013

Photovoltaic inverters are the major functional units of the photovoltaic systems. Therefore, efficiency and cost are vitally important in the design, and operation of the PV system. Magnetic components are the bulkiest component and highly affect the efficiency of the galvanically isolated PV inverter and design of such component generally involves a compromise between the reduction of core loss at the expense of increased winding loss or vice versa. The loss characteristics of the magnetic material itself present a fundamental limitation on core loss reduction, implying that the intrinsic reduction of core loss density depends on magnetic material improvements. Hence, the essential tradeo…

There is a relationship between obesity and COVID‐19 but more information is needed

2020

Abstract We read with particular interest your comments in Obesity regarding the Coronavirus‐19 (COVID‐19) epidemic (1) and a related manuscript by Simonnet et al. (2). Resolution of the specific relationship between obesity and COVID‐19, two existing public health epidemics, is critically needed to potentially prevent health systems worldwide from being overburdened. Few studies describing COVID‐19 with rates of obesity exist, and most are based on heterogeneous populations (Table 1) (2‐7). In cohort studies with COVID‐19 disease, obesity rates are generally reported as no higher than population‐based estimates; in contrast, subgroups of critically ill patients (e.g, intensive care unit (I…

1993

Let us sit on the terrace of a street cafe and watch the crowds pass by. The first basic unit we observe is the individual: tall, small, fat, long-faced, round-faced — the diversity is large. Among these individuals there will be a few with particular features, such as colour of skin or type of hair, which differ from the vast majority of local individuals, thereby indicating that they originated from another part of the world. We shall install a video camera at this site and will carry out the same observations simultaneously in Paris, Dakar, and Tokyo. When the films are then brought together and shown in the same room, the observers will not fail to note that the individuals of one city …