Search results for "TELECOMMUNICATIONS"

End-to-End Quality of Service Support

2005

A suitable control technique for fault-tolerant converters in Distributed Generation

2011

The penetration of Distributed Generation (DG) in power systems is deeply changing the existing distribution networks which is becoming a very sophisticated and complex systems incorporating both active (generators) and passive systems (distribution systems, converters and loads). The necessary simplification can be obtained dealing with small networks, namely Micro-Grids, reproducing, in a smaller scale, the structure and the problems of large networks including production, transmission and distribution of the electrical energy. In order to achieve an adequate level of reliability, fault-tolerant operations of micro-grids become very important. This result can be achieved only using power …

Green Data Centres providing ancillary services to power grid

2015

This work investigates the possibility for a Data Centre to provide services to the Grid. In particular, the paper simulates a sudden shift of frequency because of a power decrease and estimates how a real-life Data Centre can contribute the secondary frequency regulation.

Bearing fault detection for drivetrains using adaptive filters based wavelet transform

2017

Predicting a localized defect on a rolling bearing during the degradation process before a complete failure is crucial to prevent system failures, unscheduled downtimes and substantial loss of productivity. During this process, impulses associated with the fault are weak, nonstationary or time-frequency varying, and contaminated by noises, which render the problem of extracting these impulses very difficult. This work investigates the effectiveness of common signal processing techniques on predicting incipient faults, e.g. Fast Fourier transform, Short-Time Fourier transform, Wavelet transform. It was found that an adaptive filter is required to enhance and reconstruct the signals during th…

Radio measurements on a customized software defined radio module: A case study of energy detection spectrum sensing

2017

In this paper, we developed a software defined radio (SDR) system for implementing energy detection spectrum sensing. The SDR module can be used for a wide range of applications. The use of the SDR module is motivated by its high interoperability, availability for relatively cheaper prices and being software independent. Energy detection for cognitive radios is chosen for its simplicity and popularity. However, it is chosen as a representative for a very wide range of measurements and algorithms that can be implemented in the SDR. We have used probabilities of detection and false alarm with the receiver operating characteristics (ROC) curves as performance metrics for the implemented energy…

Discussion of “EDR in Circular Channels” by Subhasish Dey

2002

Analysis of proposals to reduce SAR levels from GSM terminals

2002

Is wireless communication dangerous? In recent years some scientists and lay people have expressed alarm at the possible harm mobile phones could cause to the user's health, even cancer. Handset terminals must meet standard limits based in SAR measurements. In this paper we present several proposals to minimize SAR values computed over a numerical user's head model using absorbent materials and new generation antennas.

Charging Electric Vehicles Using Opportunistic Stopovers

2017

The diffusion of electric vehicles asks for efficient energy replenishment, which requires geographical and temporal coordination of shared charging resources. We introduce a novel charging methodology that exploits users’ opportunistic mobility. This paper focuses on vehicle stopovers detecting potential charg- ing opportunities. Our mobility-assisted methodology protects users privacy and permits a hybrid centralized/distributed ap- proach avoiding clashes with other potential users. A preliminary analysis on our charging system, obtained with mobility data from the field, shows that among the available charging stations, some are more relevant and have a key role in serving electric vehi…

A distributed control system for citric fruits conservation and maturation based on CAN and Internet networks

2007

In citric fruits conservation and maturation systems it is very important to have precise information about parameters that indicate the citric fruit state. This information allows computing the appropriate control actions in order to achieve an optimum controlled citric fruit conservation and maturation. Last technological advances must be also used in this agriculture field to forget the rudimentary control systems that are being used at the present time. This paper describes a new distributed control system devoted to control citric fruits cold chambers that applies the last computer and electronics techniques. It is structured over different communication networks, making possible a rem…

Exploring FPGA‐Based Lock‐In Techniques for Brain  Monitoring Applications

2017

Functional near‐infrared spectroscopy (fNIRS) systems for e‐health applications usually suffer from poor signal detection, mainly due to a low end‐to‐end signal‐to‐noise ratio of the electronics chain. Lock‐in amplifiers (LIA) historically represent a powerful technique helping to improve performance in such circumstances. In this work a digital LIA system, based on a Zynq® field programmable gate array (FPGA) has been designed and implemented, in an attempt to explore if this technique might improve fNIRS system performance. More broadly, FPGA‐based solution flexibility has been investigated, with particular emphasis applied to digital filter parameters, needed in the digital LIA, and its …