Search results for "LESS"

Bruxismo: un disturbo della regolazione affettiva? Alessitimia e strategie di coping

2006

Fast 3D Ray Tracing for Indoor Coverage Solutions

2016

Optimal wireless indoor network planning requires huge number of iterations and evaluations of indoor coverage for each antenna location until an optimal solution is reached. Consequently, accurate and scalable calculation of power strength for indoor scenarios becomes necessary. The contribution in this paper is to reduce the complexity of 3D ray tracing for deterministic indoor power prediction. In order to achieve that while preserving the accuracy, image theory with feasible reflection volume as preprocessing approach is introduced. This proposed algorithm stores the image, its feasible reflection volume and valid area of receiving points. Significant complexity reduction is achieved by…

Recognition of Chip Forms by Means of Dynamic Force Spectrum Analysis

1993

In this study the ability to identify chip forms occurrs in the turning of austenitic stainless steel using dynamic force spectrum analysis has been tested. For this purpose the frequency spectra obtained from various metal cutting tests were recorded along with the static cutting forces. A dual channel analysis, based on the Fast Fourier Transform (FFT), was adopted to help identify the continuous/discontinuous (favourable/unfavourable) chip forming boundary. The results showed an acceptable correlation between the types of the frequency spectra and the types of chip forms. Finally, an original classification of the spectra obtained during turning of AISI 304 (DIN 1.4301) stainless steel i…

Improving IEEE 802.11 Performance in Chain Topologies through Distributed Polling and Network Coding

2009

Wireless multi-hop networks often rely on the use of IEEE 802.11 technology. Despite of the robustness of the IEEE 802.11 Distributed Coordination Function (DCF) for working in various network scenarios, it has been proven that critical inefficiencies can arise in the case of multi-hop packet forwarding. In this paper, we propose a MAC scheme, based on the virtualization of the Point Coordination Function, optimized for working on chain topologies with bidirectional traffic flows. Our scheme is based on a token-like access mechanism coupled with network coding. The basic idea is the use of multiple Point Coordinators (PCs) along the node chain, which are elected by passing special token fra…

Transitions from grid-connected to island operation of Smart Microgrids

2019

In this paper a control methodology is presented to perform a bumpless transition from the on-grid to the offgrid of a smart microgrid. The derived controller manages the internal production in order to get to zero the tie-line active and reactive power flows so that the opening of the tie line breaker does not produce significant perturbations. Experimental tests performed on the microgrid built at the Polytechnic University of Bari demonstrated the effectiveness of the proposed control strategy.

Building Information Modeling (BIM) Enabled Facilities Management Using Hadoop Architecture

2017

International audience; Protecting the safety of occupants and the environment is a core value within Facilities Management. Data acquisition systems such as wireless sensor networks can help to monitor facilities to reduce hazards such as fire, water flooding and burglaries. Building Information Modeling (BIM) is a revolutionary development that is reshaping the Architecture Engineering and Construction (AEC) industry. BIM is both a process and a technology, offers wide solutions for facilities management. In order to monitor and manage facilities data in a BIM based simulated environment, this work reports upon a development of a system that uses BIM software and a wireless sensor technol…

Design and implementation of a long-range low-power wake-up radio and customized DC-MAC protocol for LoRaWAN

2019

In this paper, we present the design and implementation of a long-rage wake-up radio (WuR) and customized duty cycled (DC) MAC protocol for wireless IoT devices. The WuRx achieves a sensivity of −70 dBm by consuming just 0.032 mA, thereby optimizing the energy consumption of battery powered long-range wireless IoT devices. Reducing the power consumption of these devices minimizes the overall costs when deployed in large scale.

Medium access in WiFi networks: strategies of selfish nodes [Applications Corner]

2009

This article provides a game theoretical analysis of the WiFi MAC protocol to understand the risks or the advantages offered by possible modifications of MAC functionalities implemented at the driver level.

Current characterisation for ultra low power wireless body area networks

2010

The emerging area of body area networks (BAN) imposes challenging requirements on hardware and software to achieve the desired lifetimes for certain devices such as long term medical implants. In this paper, we propose a novel approach to the measurement and characterisation of the energy consumption of BAN devices. The approach uses a low cost energy auditing circuit and addresses the problem of accurately measuring low-level current consumption. This new technique will allow precise and analytical measurements of systems and components in terms of energy. This will help circuit designers minimise power consumption in BAN devices. Software engineers might use this approach to validate and …

A spatial role-based authorization framework for sensor network-assisted indoor WLANs

2009

©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Article also available from publisher: http://dx.doi.org/10.1109/WIRELESSVITAE.2009.5172549 In this paper, we propose a spatial role-based authorization framework which specifies authorization based on both role and location constrains in a wireless local area network with assistance from a sensor network. The framework performs a location-restricted verificati…