Search results for "PAC"
showing 10 items of 28794 documents
Lidar detection of carbon dioxide in volcanic plumes
2015
Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidar has been undertaken at the Diagnostics and Metrology Laboratory (UTAPRAD-DIM) of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high s…
Volcanic Plume CO2 Flux Measurements at Mount Etna by Mobile Differential Absorption Lidar
2017
Volcanic eruptions are often preceded by precursory increases in the volcanic carbon dioxide (CO2) flux. Unfortunately, the traditional techniques used to measure volcanic CO2 require near-vent, in situ plume measurements that are potentially hazardous for operators and expose instruments to extreme conditions. To overcome these limitations, the project BRIDGE (BRIDging the gap between Gas Emissions and geophysical observations at active volcanoes) received funding from the European Research Council, with the objective to develop a new generation of volcanic gas sensing instruments, including a novel DIAL-Lidar (Differential Absorption Light Detection and Ranging) for remote (e.g., distal) …
Decoupled control scheme of grid-connected split-source inverters
2017
Grid-connected power conversion systems for renewable energy sources must fulfill several requirements, e.g., the high efficiency, the reduced cost and complexity, and, quite often, the boost capabilities that is usually achieved using a front-end dc–dc boost converter before the inversion stage, leading to a two-stage architecture. Meanwhile, single-stage power conversion systems, which perform the boosting operation within the inversion one, offer some potential advantages, in terms of reducing the complexity and the volume of the whole system. Among several proposed options, the split-source inverter (SSI) has been recently proposed by Abdelhakim et al. as an alternative option with some…
Relationship between volume and energy of vector fields
2001
Abstract A unified study of energy and volume functionals is presented here by determining the critical points of a functional that extends simultaneously energy and volume and that is defined on the product of the manifold of smooth maps C∞(M,N) times the manifold M of riemannian metrics on M. The restriction of this functional to different submanifolds of the space of vector fields X (M)× M is also considered, and used to study several functionals generalizing volume and energy or total bending of vector fields
Territorio, vulnerabiliadd social y trayectoria delictiva en adolescentes de la ciudad de Valencia
2012
Se trata de una aproximación a los espacios de exclusión de la ciudad de Valencia a partir de la información sobre delincuencia juvenil y la provisión de servicios sociales. El territorio, en particular en el interior de las ciudades, es desigual. Dicha desigualdad es resultado de las características socioeconómicas de su población pero también de la oferta de servicios y equipamientos públicos. El resultado de esta compleja combinación es la existencia de espacios vulnerables y de población en riesgo de exclusión social. La delincuencia juvenil es uno de los factores que caracterizan estos territorios que, además, adolecen de galta de infraestructuras sólidas de apoyo a la población que fa…
Cybersecurity Attacks on Software Logic and Error Handling Within ADS-B Implementations: Systematic Testing of Resilience and Countermeasures
2022
Automatic Dependent Surveillance-Broadcast (ADS-B) is a cornerstone of the next-generation digital sky and is now mandated in several countries. However, there have been many reports of serious security vulnerabilities in the ADS-B architecture. In this paper, we demonstrate and evaluate the impact of multiple cyberattacks on ADS-B via remote radio frequency links that affected various network, processing, and display subsystems used within the ADS-B ecosystem. Overall we implemented and tested 12 cyberattacks on ADS-B in a controlled environment, out of which 5 attacks were presented or implemented for the first time. For all these attacks, we developed a unique testbed that consisted of 1…
Behavioural, ecological, and evolutionary aspects of diversity in frog colour patterns
2017
The role of colours and colour patterns in behavioural ecology has been extensively studied in a variety of contexts and taxa, while almost overlooked in many others. For decades anurans have been the focus of research on acoustic signalling due to the prominence of vocalisations in their communication. Much less attention has been paid to the enormous diversity of colours, colour patterns, and other types of putative visual signals exhibited by frogs. With the exception of some anecdotal observations and studies, the link between colour patterns and the behavioural and evolutionary ecology of anurans had not been addressed until approximately two decades ago. Since then, there has been eve…
From ‘no dogs here!’ to ‘beware of the dog!’ : restricting dog signs as a reflection of social norms
2019
Signs in public space reflect ‘normalcy’ in a community. The authors ask what restricting signs tell us about a society? In order to explore the system and variation in the ways dog signs manifest different norms and control, they compare two different data sets: dog signs in a Northern European town, Jyväskylä in Finland, and two Eastern European villages in Romania. They apply a qualitative methodology based on visual communication, geosemiotics and linguistic landscape studies. The focus of the article is on the resources of addressing and the visual semiotics of the image. The investigated communities seem to create a complementary distribution of what they regulate that is also displa…
Anomaly detection using one-class SVM with wavelet packet decomposition
2011
Anomaly detection has become a popular research topic in the field of machine learning. Support vector machine is one anomaly detection technique and it is coming one the most widely used. In this research, anomaly detection is applied to road condition monitoring, especially pothole detection, using accelerometer data. The proposed concept includes data preprocessing, feature extraction, feature selection and classification. Accelerometer data was first filtered and segmented, after which features were extracted with frequency- and time-domain functions, with genetic programming and with wavelet packet decomposition. A classification model was built using support vector machine and the cal…
Una más de la familia. Au pairs atrapadas entre el capital humano y la economía moral
2018
In contemporary societies we are witnessing an expansion of the messages of human capital. These messages have as their central dimension idea of the self-entrepreneur, which implies a deepening in the logic of activation, while blurring the wage relations. In this scenario, young people with university degrees are becoming a favourite target in the offensive of human capital. The penetration of these human capital messages can be seen in the discourses of young university students who have been forced to leave the country during the crisis. In the present text we approach the discourses of young women who came out as au pairs. The characteristics of this figure place it in a space halfway …