Search results for "Networks"
showing 10 items of 3260 documents
Cross-technology wireless experimentation: Improving 802.11 and 802.15.4e coexistence
2016
In this demo we demonstrate the functionalities of a novel experimentation framework, called WiSHFUL, that facilitates the prototyping and experimental validation of innovative solutions for heterogeneous wireless networks, including cross-technology coordination mechanisms. The framework supports a clean separation between the definition of the logic for optimizing the behaviors of wireless devices and the underlying device capabilities, by means of a unifying platform-independent control interface and programming model. The use of the framework is demonstrated through two representative use cases, where medium access is coordinated between IEEE-802.11 and IEEE-802.15.4 networks.
Modelling the Interaction between Air Pollutant Emissions and Their Key Sources in Poland
2021
The main purpose of this study is to investigate the relationships between key sources of air pollutant emissions (sources of energy production, factories which are particularly harmful to the environment, the fleets of cars, environmental protection expenditure) and the main environmental air pollution (SO2, NOx, CO and PM) in Poland. Models based on MLP neural networks were used as predictive models. Global sensitivity analysis was used to demonstrate the significant impact of individual network input variables on the output variable. To verify the effectiveness of the models created, the actual data were compared with the data obtained through modelling. Projected courses of changes in t…
Tecnologías y cultura organizativa en los centros escolares. ¿La uberización de las relaciones laborales?
2020
El supuesto sobre el que se sustenta el presente trabajo, inspirado en las teorías clásicas de la organización, propone que el uso de dispositivos digitales en los centros escolares, especialmente de plataformas digitales, genera una cultura tecnológica entre el profesorado. El objetivo de este artículo es analizar las consecuencias de este fenómeno sobre la reestructuración del entramado organizativo del centro y del trabajo docente. Para ello, se parte de un estudio de casos múltiples en cuatro centros de Educación Primaria aplicando estrategias etnográficas, entre las que destacan las entrevistas realizadas al personal docente (profesorado, equipos directivos, titulares de centro). El an…
Layout influence on microwave performance of graphene field effect transistors
2018
The authors report on an in-depth statistical and parametrical investigation on the microwave performance of graphene FETs on sapphire substrate. The devices differ for the gate-drain/source distance and for the gate length, having kept instead the gate width constant. Microwave S -parameters have been measured for the different devices. Their results demonstrate that the cut-off frequency does not monotonically increase with the scaling of the device geometry and that it exists an optimal region in the gate-drain/source and gate-length space which maximises the microwave performance.
Formulations and valid inequalities for the capacitated dispersion problem
2023
This work focuses on the capacitated dispersion problem for which we study several mathematical formulations in different spaces using variables associated with nodes, edges, and costs. The relationships among the presented formulations are investigated by comparing the projections of the feasible sets of the LP relaxations onto the subspace of natural variables. These formulations are then strengthened with families of valid inequalities and variable-fixing procedures. The separation problems associated with the valid inequalities that are exponential in number are shown to be polynomially solvable by reducing them to longest path problems in acyclic graphs. The dual bounds obtained from s…
RF Acquisition System Based on μTCA for Testing of High-Gradient Acceleration Cavities
2022
The radio frequency (RF) laboratory hosted in the Corpuscular Physics Institute (IFIC) of the University of Valencia is designed to house a high-power and high-repetition-rate facility to test normal conduction RF accelerator cavities in the S-Band (2.9985 GHz) in order to perform R&D activities related to particle accelerator cavities. The system, which manages the entire process of RF signal generation, data acquisition and closed-loop control of the laboratory, is currently based on a modular and compact PXI platform system. This contribution details the development of a platform with similar features, but which is based on open architecture standards at both the hardware and softwar…
Trajectory of Affordances: Insights from a case of telemedicine in Nepal
2017
Although Affordance Theory has become increasingly influential in the Information Systems (IS) literature, the exact process through which the affordances of IT are actualised is less studied. In t ...
RFID Technology for IoT-Based Personal Healthcare in Smart Spaces
2014
The current evolution of the traditional medical model toward the participatory medicine can be boosted by the Internet of Things (IoT) paradigm involving sensors (environmental, wearable, and implanted) spread inside domestic environments with the purpose to monitor the user’s health and activate remote assistance. RF identification (RFID) technology is now mature to provide part of the IoT physical layer for the personal healthcare in smart environments through low-cost, energy-autonomous, and disposable sensors. It is here presented a survey on the state-of-the-art of RFID for application to bodycentric systems and for gathering information (temperature, humidity, and other gases) about …
An IoT and Fog Computing-Based Monitoring System for Cardiovascular Patients with Automatic ECG Classification Using Deep Neural Networks
2020
Telemedicine and all types of monitoring systems have proven to be a useful and low-cost tool with a high level of applicability in cardiology. The objective of this work is to present an IoT-based monitoring system for cardiovascular patients. The system sends the ECG signal to a Fog layer service by using the LoRa communication protocol. Also, it includes an AI algorithm based on deep learning for the detection of Atrial Fibrillation and other heart rhythms. The automatic detection of arrhythmias can be complementary to the diagnosis made by the physician, achieving a better clinical vision that improves therapeutic decision making. The performance of the proposed system is evaluated on a…
A linear generator for a waveroller power device
2017
In this paper experimental tests on a small scale tubular linear generator to be applied to wave rollers device are presented. A reduced scale of gnerator is presented and experimental results obtained in on test bench are shown. Experimental waveforms of current and voltage are recorded. Simulation results are compared to the experimental ones in order to validate the mathematical models used.