Search results for "Wire"
showing 10 items of 1383 documents
Realization of a robust single-parameter quantized charge pump
2008
This paper describes a novel scheme for quantized charge pumping based on single-parameter modulation. The device is realized in an AlGaAs-GaAs gated nanowire. A particular advantage of this realization is that operation in the quantized regime can be achieved in a potentially large range of amplitude and dc off-set of the driving signal. This feature together with the simple configuration might enable large scale parallel operation of many such devices.
Modelling leaky photonic wires: a mode solver comparison
2006
We present results from a mode solver comparison held within the framework of the European COST P11 project. The structure modelled is a high-index contrast photonic wire in silicon-oninsulator subject to substrate leakage. The methods compared are both in-house developed and commercial, and range from effective index and perturbation methods, over finite-element and finite-difference codes, beam propagation methods, to film mode matching methods and plane wave expansion methods.
Exploring Training Options for RF Sensing Using CSI
2018
This work analyzes human behavior recognition approaches using WiFi channel state information from the perhaps less usual point of view of training and calibration needs. With the help of selected literature examples, as well as with more detailed experimental insights on our own Doppler spectrum-based approach for physical motion/presence/cardinality detection, we first classify the diverse forms of training so far employed into three main categories (trained, trained-once, and training-free). We further discuss under which conditions it is possible to move toward lighter forms of calibration or even succeed in devising fully untrained model-based solutions. Our take home messages are main…
Urban Air Quality Monitoring Using Vehicular Sensor Networks
2014
The quality of air is a major concern in modern cities as pollutants have been demonstrated to have significant impact on human health. Networks of fixed monitoring stations have been deployed in urban areas to provide authorities with data to define and enforce dynamically policies to reduce pollutants, for instance by issuing traffic regulation measures. However, fixed networks require careful placement of monitoring stations to be effective. Moreover, changes in urban arrangement, activities, or regulations may affect considerably the monitoring model, especially when budget constraints prevent from relocating stations or adding new ones to the network. In this chapter we discuss a diffe…
Supramolecular silver polyoxometalate architectures direct the growth of composite semiconducting nanostructures.
2009
Nanosilver on a string: Crystalline silver polyoxovanadate supramolecular architectures are employed as precursors for the synthesis of composite nanowires (see scheme). The nanostructures are composed of semiconducting vanadium oxide which forms wires with high aspect ratios, and are embedded with metallic silver nanoparticles. © 2009 Wiley-VCH Verlag GmbH & Co. KCaA.
A novel technique for the CMRR improvement in a portable ECG system
2017
This paper presents a new technique to improve the quality of the ECG signals, increasing the Common Mode Rejection Ratio (CMRR). We developed a portable wireless Bluetooth ECG system able to acquire 12 leads, communicating with Smartphones and PCs. Many experiments have been made for measuring CMRR decay due to the difference on skin-electrodes impedances, the asymmetries of the amplifiers input stages and external components. Using some digital potentiometers, the system is able to compensate for these, increasing the CMRR of about 18 dB.
Bluetooth Base Station Minimal Deployment for High Definition Positioning
2005
This paper discusses our approach to the problem of arranging a Bluetooth based positioning system capable of providing people coordinates in a given area with an accuracy as high as possible. Our strategy focuses on optimizing the disposition of a minimal number of available Bluetooth base stations in a subset of locations which are the only ones permitted by site characteristics and constraints. We used a genetic algorithm to this purpose and a layout chromosome whose best evolution suggested us how to deploy a minimal set of Bluetooth base stations. As a case study, we discuss our experiments and results which deal with a late middle age castle in Sicily where we carried out many trials.
Electrodeposited nickel–zinc alloy nanostructured electrodes for alkaline electrolyzer
2022
Abstract Over the last decade, as a consequence of the global decarbonization process, the interest towards green hydrogen production has drastically increased. In particular a substantial research effort has focused on the efficient and affordable production of carbon-free hydrogen production processes. In this context, the development of more efficient electrolyzers with low-cost electrode/electrocatalyst materials can play a key role. This work, investigates the fabrication of electrodes of nickel-zinc alloys with nanowires morphology cathode for alkaline electrolyzers. Electrodes are obtained by the simple method of template electrosynthesis that is also inexpensive and easily scalable.…
A hybrid storage system for wireless sensor nodes powered with energy harvesting
2019
With the recent development of Internet of Things (IoT) and Wireless Sensor Networks (WSN), research and industry have been increasingly focusing on the opportumty of collecting the energy arising from the environment. The Energy Harvesting provides the possibility to supply devices which are placed out of reach or in hazardous spots, e.g. the Wireless Sensor Nodes. Among the different parts belonging to an Energy Harvesting system, the power management network represents a challenging topic. In this paper a Hybrid Energy Storage System (HESS) usable for a WSN powered with Energy Harvesting, based on a battery-capacitor integration, is presented. The experimental results concerning the asse…
Compliance of IEEE 802.22 WRAN for field area network in smart grid
2016
Distributed power system network is going to be complex, and it will require high-speed, reliable and secure communication systems for managing intermittent generation with coordination of centralised power generation, including load control. Cognitive Radio (CR) is highly favourable for providing communications in Smart Grid by using spectrum resources opportunistically. The IEEE 802.22 Wireless Regional Area Network (WRAN) having the capabilities of CR use vacant channels opportunistically in the frequency range of 54 MHz to 862 MHz occupied by TV band. A comprehensive review of using IEEE 802.22 for Field Area Network in power system network using spectrum sensing (CR based communication…