Search results for " sensor"
showing 10 items of 1714 documents
SCARKER: A sensor capture resistance and key refreshing scheme for mobile WSNs
2011
How to discover a captured node and to resist node capture attack is a challenging task in Wireless Sensor Networks (WSNs). In this paper, we propose a node capture resistance and key refreshing scheme for mobile WSNs which is based on the Chinese remainder theorem. The scheme is able of providing forward secrecy, backward secrecy and collusion resistance for diminishing the effects of capture attacks. By implementing our scheme on a Sun SPOT based sensor network testbed, we demonstrate that the time for updating a new group key varies from 56 ms to 546 ms and the energy consumption is limited to 16.5–225 mJ, depending on the length of secret keys and the number of sensors in a group.
Analysis of the Effect of Human Presence on a Wireless Sensor Network
2011
Wireless Sensor Networks (WSNs) are gaining an increasing industry wide adoption. However, there remain major challenges such as network dimensioning and node placement especially in Built Environment Networks (BENs). Decisions on the node placement, orientation, and the number of nodes to cover the area of interest are usually ad-hoc. Ray tracing tools are traditionally employed to predict RF signal propagation; however, such tools are primarily intended for outdoor environments. RF signal propagation varies greatly indoors due to building materials and infrastructure, obstacles, node placement, antenna orientation and human presence. Because of the complexity of signal prediction, these f…
WiseNET - smart camera network interacting with a semantic model
2016
This paper presents an innovative concept for a distributed system that combines a smart camera network with semantic reasoning. The proposed system is context sensitive and combines the information extracted by the smart camera with logic rules and knowledge of what the camera observes, building information and events that may occurred. The proposed system is a justification for the use of smart cameras, and it can improve the classical visual sensor networks (VSN) and enhance the standard computer vision approach. The main application of our system is smart building management, where we specifically focus on increasing the services of the building users.
Auxilum Medicine: A Cloud Based Platform for Real-Time Monitoring Medical Devices
2015
Nowadays, time is a very valuable resource and can make the difference between life and death. Having knowledge about this fact we decided to deal with one of the most important aspects of contemporary medicine, EMS (emergency medical services) response time. Modern systems that encourage intelligent communication methods between medical devices and doctors are a must in ubiquitous health care environments. Auxilum Medicine fosters a triple-win situation regarding the relationship between medical institutions, doctors and patients. Emergency patients should be treated with utmost care because their life is hanging by a thread if nobody is present to take immediate action. We are presenting …
MansOS
2010
Often software for wireless sensor networks (WSNs) is developed using a specific event based operating system (OS) such as TinyOS. However, this requires steep learning curve for the new developers. Other operating systems for embedded devices have limited support for new hardware platforms. Our goal is to provide an operating system for resource constrained devices that is easy to use for the wide range of researchers and developers familiar with C programming language and Unix operating system concepts. In addition, we provide a framework for agile portability to new hardware platforms, due to the nature of WSN systems that require specific hardware or features for the sensing tasks at ha…
Adapting robot paths for automated NDT of complex structures using ultrasonic alignment
2019
Automated inspection systems using industrial robots have been available for several years. The IntACom robot inspection system was developed at TWI Wales and utilizes phased array ultrasonic probes to inspect complex geometries, in particular aerospace composite components. To increase inspection speed and accuracy, off-line path planning is employed to define a series of robotic movements following the surface of a component. To minimize influences of refraction at the component interface and effects of anisotropy, the ultrasonic probe must be kept perpendicular to the surface throughout the inspection. Deviations between the actual component and computer model used for path-planning resu…
Progress in analysis of residual antibacterials in food
2007
Abstract Residual antibacterials in food constitute a risk to human health. Although epidemiological data on the real magnitude of their adverse effects are very scarce, they indicate that food could be an important avenue for evolution and dissemination of antibiotic-resistant bacteria. Analysis of these residues plays a key role in ensuring food safety, to the point that the European Union has not only established maximum residue limits but also requirements concerning the performance of analytical methods and the interpretation of the results. These specifications have had a great influence on protocols and techniques applied. In this review, we discuss the progress of rapid screening me…
Stochastic Graph Filtering Under Asymmetric Links in Wireless Sensor Networks
2018
Wireless sensor networks (WSN s) are often characterized by random and asymmetric packet losses due to the wireless medium, leading to network topologies that can be modeled as random, time-varying and directed graphs. Most of existing works related to graph filtering in the context of WSNs assume that the probability of delivering an information from one node to a neighbor node is the same as in the reverse direction. This assumption is not realistic due to the typical link asymmetry in WSNs caused by interferences and background noise. In this work, we analyze the problem of applying stochastic graph filtering over random time-varying asymmetric network topologies. We show that it is poss…
Low-Cost Sensor Based on SDR Platforms for TETRA Signals Monitoring
2021
The paper presents the design and implementation of an electromagnetic field monitoring sensor for the measurement of the Terrestrial Truncked Radio (TETRA) signals using low-cost software defined radio (SDR) platforms. The sensor includes: an SDR platform, a Global Positioning System (GPS) module and a hardware control module. Several SDR platforms having different resolutions of the analog–digital converters were tested in the first phase. The control module was implemented in two variants: a fixed one, using a laptop, and a mobile one, using a Raspberry Pi. The tests demonstrate the following achieved performances: instantaneous acquisition band of 5.12 MHz
Measurements of pressure and frictional tractions along walls of a large-scale conical shallow hopper and comparison with Eurocode 1991-4:2006
2014
Abstract A silo׳s hopper supports the majority loads induced by the stored particulate solids. Such loads vary from filling to discharging provided the hopper is steep enough to secure a mass flow; when the hopper is too shallow to promote a mass flow, funnel flow usually prevails – where how loads develop along walls of a shallow hopper remains to be addressed. In the paper, normal pressure and frictional traction were measured with pressure transducers as imposed by testing material sand along the walls of a full-scale conical shallow hopper. The transducers were carefully mounted in the designated positions of hopper walls along a generator. To make the measurement results representative…