3D Simulation of Partial Discharge in High Voltage Power Networks

Open accessPartial discharge (PD) events arise inside power cables due to defects of cable’s insulation material, characterized by a lower electrical breakdown strength than the surrounding dielectric material. These electrical discharges cause signals to propagate along the cable, manifesting as noise phenomena. More significantly, they contribute to insulation degradation and can produce a disruptive effect with a consequent interruption of power network operation. PD events are, therefore, one of the best ‘early warning’ indicators of insulation degradation and, for this reason, the modeling and studying of such phenomena, together with the development of on-line PDs location methods, are important topics for network integrity assessment, and to define methods to improve the power networks’ Electricity Security. This paper presents a 3D model of PD events inside a void in epoxy-resin insulation cables for High Voltage (HV) power networks. The 3D model has been developed using the High Frequency (HF) Solver of CST Studio Suite® software. PD events of a few µs duration have been modelled and analyzed. The PD behavior has been investigated using varying electrical stress. A first study of the PD signal propagation in a power network is described

Permissions Snapshots: Assessing Users' Adaptation to the Android Runtime Permission Model

The Android operating system changed its security and privacy-related permission model recently, offering its users the ability to control resources that applications are allowed to access on their devices. This major change to the traditional coarse-grained permission system was anticipated for a long time by privacy-aware users. This paper presents the first study that analyzes Android users' adaptation to the fine-grained runtime permission model, regarding their security and privacy controls. We gathered anonymous data from 50 participants who downloaded our application and answered questions related to the new permission model. The results indicate that the majority of users prefer the new model. We also collected data that demonstrate users' security controls at the given time. Our analysis shows that individuals make consistent choices regarding the resources they allow to various applications to access

A two-way interactive broadband satellite architecture to break the digital divide barrier

September 24-26, 2007, Turin, Ital

TV-Centric technologies to provide remote areas with two-way satellite broadband access

October 1-2, 2007, Rome, Italy TV-Centric Technologies To Provide Remote Areas With Two-Way Satellite Broadband Acces

Straight from the heart: using physiological measurements in the evaluation of multimedia quality

Subjective methods are widely used to evaluate Multimedia Conferencing quality, yet when used in isolation the results can be misleading. Therefore, this research is measuring physiological indicators of stress (GSR, HR & BVP) as an indicator of the user cost of the reception quality of a multimedia conference. These measurements are taken as part of a 3-Dimensional approach, which incorporates task performance, user satisfaction and user cost. The main results have shown that subjective and physiological responses do not always correlate and that specific physiological signals respond differently depending on the degradation and task. The ability to measure stress subconsciously and unobtrusively has many potential application

Vertebrate Natural History Notes from Arkansas, 2017

Because meaningful observations of natural history are not always part of larger studies, important pieces of information often are unreported. Small details, however, can fills gaps in understanding and also lead to interesting questions about ecological relationships or environmental change. We have compiled recent observations of foods, reproduction, record size, parasites, and distribution of 30 species of fishes, new records of distribution and parasites of 2 species of amphibians, and new records of distribution, parasites, reproduction and anomalies of 11 species of mammals

Personalised Focus-Metaphor Interfaces: An Eye Tracking Study on User Confusion

Personalised web interfaces are expected to improve user interaction with web content. But since the delivery of personalised web content is currently not reliable, a key question is how much users may be confused and slowed down when personalised delivery goes wrong. The aim of the study reported in this paper was to investigate a worst-case scenario of failed personalised content presentation – a dynamic presentation of content where content was dynamically presented, but content units were selected at random. We employed eye-tracking to monitor the differences in users’ attention and navigation when interacting with this “dysfunctional” dynamic interface, and a static version. We found that subjects who interacted with the dysfunctional version took 10% longer to read their material than those with static content, and displayed a different strategy in scanning the interface. The relatively small difference in navigation time in first-time viewers of dynamically presented content, and of the results from the eye-tracking patterns, suggests that users are not significantly confused and slowed down by dynamic presentation of content when using a Focus-Metaphor interfac