17,651 research outputs found
Time domain analysis of switching transient fields in high voltage substations
Switching operations of circuit breakers and disconnect switches generate transient currents propagating along the substation busbars. At the moment of switching, the busbars temporarily acts as antennae radiating transient electromagnetic fields within the substations. The radiated fields may interfere and disrupt normal operations of electronic equipment used within the substation for measurement, control and communication purposes. Hence there is the need to fully characterise the substation electromagnetic environment as early as the design stage of substation planning and operation to ensure safe operations of the electronic equipment. This paper deals with the computation of transient electromagnetic fields due to switching within a high voltage air-insulated substation (AIS) using the finite difference time domain (FDTD) metho
Investigations on electromagnetic noises and interactions in electronic architectures : a tutorial case on a mobile system
Electromagnetic interactions become critic in embedded and smart electronic structures. The increase of electronic performances confined in a finite volume or support for mobile applications defines new electromagnetic environment and compatibility configurations (EMC). With canonical demonstrators developed for tutorials and EMC experiences, this paper present basic principles and experimental techniques to investigate and control these severe interferences. Some issues are reviewed to present actual and future scientific challenges for EMC at electronic circuit level
Radio Frequency Interference Mitigation
Radio astronomy observational facilities are under constant upgradation and
development to achieve better capabilities including increasing the time and
frequency resolutions of the recorded data, and increasing the receiving and
recording bandwidth. As only a limited spectrum resource has been allocated to
radio astronomy by the International Telecommunication Union, this results in
the radio observational instrumentation being inevitably exposed to undesirable
radio frequency interference (RFI) signals which originate mainly from
terrestrial human activity and are becoming stronger with time. RFIs degrade
the quality of astronomical data and even lead to data loss. The impact of RFIs
on scientific outcome is becoming progressively difficult to manage. In this
article, we motivate the requirement for RFI mitigation, and review the RFI
characteristics, mitigation techniques and strategies. Mitigation strategies
adopted at some representative observatories, telescopes and arrays are also
introduced. We also discuss and present advantages and shortcomings of the four
classes of RFI mitigation strategies, applicable at the connected causal
stages: preventive, pre-detection, pre-correlation and post-correlation. The
proper identification and flagging of RFI is key to the reduction of data loss
and improvement in data quality, and is also the ultimate goal of developing
RFI mitigation techniques. This can be achieved through a strategy involving a
combination of the discussed techniques in stages. Recent advances in high
speed digital signal processing and high performance computing allow for
performing RFI excision of large data volumes generated from large telescopes
or arrays in both real time and offline modes, aiding the proposed strategy.Comment: 26 pages, 10 figures, Chinese version accepted for publication in
Acta Astronomica Sinica; English version to appear in Chinese Astronomy and
Astrophysic
Roadmap on semiconductor-cell biointerfaces.
This roadmap outlines the role semiconductor-based materials play in understanding the complex biophysical dynamics at multiple length scales, as well as the design and implementation of next-generation electronic, optoelectronic, and mechanical devices for biointerfaces. The roadmap emphasizes the advantages of semiconductor building blocks in interfacing, monitoring, and manipulating the activity of biological components, and discusses the possibility of using active semiconductor-cell interfaces for discovering new signaling processes in the biological world
Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology
INE/AUTC 10.0
Communication system for a tooth-mounted RF sensor used for continuous monitoring of nutrient intake
In this Thesis, the communication system of a wearable device that monitors the user’s diet is studied. Based in a novel RF metamaterial-based mouth sensor, different decisions have to be made concerning the system’s technologies, such as the power source options for the device, the wireless technology used for communications and the method to obtain data from the sensor. These issues, along with other safety rules and regulations, are reviewed, as the first stage of development of the Food-Intake Monitoring projectOutgoin
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