58 research outputs found
Physical detection of misbehavior in relay systems with unreliable channel state information
We study the detection 1 of misbehavior in a Gaussian relay system, where the source transmits information to the destination with the assistance of an amplify-and-forward relay node subject to unreliable channel state information (CSI). The relay node may be potentially malicious and corrupt the network by forwarding garbled information. In this situation, misleading feedback may take place, since reliable CSI is unavailable at the source and/or the destination. By classifying the action of the relay as detectable or undetectable, we propose a novel approach that is capable of coping with any malicious attack detected and continuing to work effectively in the presence of unreliable CSI. We demonstrate that the detectable class of attacks can be successfully detected with a high probability. Meanwhile, the undetectable class of attacks does not affect the performance improvements that are achievable by cooperative diversity, even though such an attack may fool the proposed detection approach. We also extend the method to deal with the case in which there is no direct link between the source and the destination. The effectiveness of the proposed approach has been validated by numerical results
MyHealthAvatar and CARRE: case studies of interactive visualisation for Internet-enabled sensor-assisted health monitoring and risk analysis
With the progress of wearable sensor technologies, more wearable health sensors have been made available on the market, which enables not only people to monitor their health and lifestyle in a continuous way but also doctors to utilise them to make better diagnoses. Continuous measurement from a variety of wearable sensors implies that a huge amount of data needs to be collected, stored, processed and presented, which cannot be achieved by traditional data processing methods. Visualisation is designed to promote knowledge discovery and utilisation via mature visual paradigms with well-designed user interactions and has become indispensable in data analysis. In this paper we introduce the role of visualisation in wearable sensor-assisted health analysis platforms by case studies of two projects funded by the European Commission: MyHealthAvatar and CARRE. The former focuses on health sensor data collection and lifestyle tracking while the latter aims to provide innovative means for the management of cardiorenal diseases with the assistance of wearable sensors. The roles of visualisation components including timeline, parallel coordinates, map, node-link diagrams, Sankey diagrams, etc. are introduced and discussed
The Relationship Between RATS-splines and the Catmull and Clark B-splines
This paper presents the relationship between the Recursive Arbitrary Topology Splines (RATS) method, derived by the authors, and the Catmull and Clark recursive B-Spline method. Both methods are capable of defining surfaces of any arbitrary topology of control points. They "fill-in" n-sided regions with four-sided patches. The Catmull & Clark method is derived from the midpoint subdivision of B-splines whereas the RATS method is derived from the midpoint subdivision of Bézier splines. RATS generates an additional set of patches defining the border of the surface but the RATS inner surface is identical to the Catmull and Clark surface. This paper illustrates this relationship between the two methods
The relation between rats-splines and the catmull and clark b-splines
This paper presents the relationship between the Recursive Arbitrary Topology Splines (RATS) method,
derived by the authors, and the Catmull and Clark recursive B-Spline method. Both methods are capable
of defining surfaces of any arbitrary topology of control points. They "fill-in" n-sided regions with foursided
patches. The Catmull & Clark method is derived from the midpoint subdivision of B-splines
whereas the RATS method is derived from the midpoint subdivision of Bézier splines. RATS generates an
additional set of patches defining the border of the surface but the RATS inner surface is identical to the
Catmull and Clark surface. This paper illustrates this relationship between the two methods
Fast realistic modelling of muscle fibres
In this paper, we describe a method for automatic construction of arbitrary number of muscle fibres in the volume of a muscle represented by its surface mesh. The method is based on an iterative, slice-by-slice, morphing of predefined fibres template into the muscle volume. Our experiments with muscles of thighs and pelvis show that in most cases, the method produces realistic fibres. For some muscles, especially, those with large attachment areas, some imperfections are observable; however, results are acceptable anyway. As our sequential VTK-based C++ implementation is capable of producing 128 fine fibres within a muscle of 10K triangles in 380 ms on commodity hardware (Intel i7), the method is suitable for interactive educational medical software. We believe that it could also be used in clinical biomechanical applications to extract information on the current muscle lever arm and fibre path.</p
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