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Wearable watches provide very useful linear acceleration information that can be use to detect falls. Howeverfalls not from a standing position are difficult to spot amongother normal activities. This paper describes methods, basedon pattern recognition using machine learning, to improve thedetection of "soft falls". The values of the linear accelerometersare combined in a robust vector...
The availability of radio spectrum is limited. The demand for high data transmission requires the increase in the spectrum which over burdens the available frequency spectrum because of licensed spectrum management. But on the other hand the studies indicate that the licensed spectrum is underutilized. Therefore this underutilized spectrum needs to be relocated dynamically so that the spectrum can...
In this paper, we present the design, implementation and evaluation of a user authentication system, Headbanger, for smart head-worn devices, through monitoring the user's unique head-movement patterns in response to an external audio stimulus. Compared to today's solutions, which primarily rely on indirect authentication mechanisms via the user's smartphone, thus cumbersome and susceptible to adversary...
Cognitive radio networks (CRNs) enable cognitive users (CUs equipped with spectrum sensing) access the underutilized spectrum licensed to primary users (PUs) without causing unacceptable interference to the PUs' activities. On appearance of PUs, the available channel of CUs at different position may have different available channels which changes dynamically over time. Due to temporal and spatial...
A design for underwater network management is proposed in this paper. The underwater network is a tree-shaped construction and has several sub-networks. Being a hierarchy network, every sub-network has a center node that is the gateway of the network, and the sonobuoy is played as center node. Autonomous Underwater Vehicles (AUVs) are the common nodes, and equipped with sonar and underwater acoustic...
Compressive Sensing (CS) is a stable and robust technique that allows for the sub-sampling of data at a given data rate: ‘compressive sampling’ or ‘compressive sensing’ at rates smaller than the Nyquist sampling rate. It makes it possible to create standalone and net-centric applications with fewer resources required in Internet of Things (IoT). CS-based signal and information acquisition/compression...
Cognitive radio (CR) tends to be the key technology of future wireless networks as it provides the mechanism of enabling the spectrum sensing awareness. The first stage in the cognitive radio duty cycle is spectrum sensing (SS) which is the most challenging stage as it requires an accurate real-time decision of the Primary User (PU) presence or absence in a certain band and allow the Secondary User...
We present a fast and efficient Structure-from-Motion (SfM) pipeline for refinement of camera parameters and 3D scene reconstruction given initial noisy camera metadata measurements. Examples include aerial Wide Area Motion Imagery (WAMI) which is typically acquired in a circular trajectory and other sequentially ordered multiview stereo imagery like Middlebury, Fountain or body-worn videos. Image...
In this paper we introduce a new dataset and pose invariant sampling method and describe the ensemble methods used for recognizing faces in 3D scenes, captured using commodity depth sensors. We use the 3D SIFT key point detector to take advantage of the similarities between faces, which leads to a set of points of interest based on the curvature of the face. For all key points, features are extracted...
Time-frequency (TF) based cognitive radio (CR) sensing schemes have to operate in different environments. In case of completely known distributions of observations under both primary user (PU) present and PU absent hypotheses, sensing can be based on a conventional likelihood ratio testing approach. However, if the observations contain unknown interference signals the conventional approach has to...
The multipulse converters are widely applied in the AC-DC conversion, once these structures take advantage of the phase-displacement provided by the transformer or autotransformer to mitigate part of the harmonic content injected in the grid. This work proposes a novel structure using a half-controlled multipulse boost-based converter, operating in Discontinuous Conduction Mode (DCM) aiming reducing...
This paper considers the problem of cooperative spectrum sensing (CSS) in the censoring-enabled Cognitive Radio Networks (CRNs) with a crowd of battery-powered Secondary Users (SUs), where only significant local observations are submitted to the Fusion Center (FC). However, in order to monopolize the spectrum usage or disrupt the networks operation, malicious SUs may try to send falsified sensing...
Wireless sensor networks (WSNs) are widely used for underwater environment monitoring. Because of the harsh underwater environment, WSNs face the challenges of erroneous communication, lower lifetime, less robustness, and cost constraints. In this paper, we propose a cooperative WSN which uses a cooperative coded OFDM (COFDM) system and network coding to deal with the shadowing phenomenon present...
The paper deals with the approach to design of the two-axis robust system for stabilization of information-measuring devices (cameras, laser locators) operated at small unmanned aerial vehicles. The mathematical description of the system taking into consideration interconnection between channels is suggested. Approach to the system structural robust optimization is given.
Micromachined capacitive inertial sensors embedded in higher order sigma-delta modulator (SDM) have a promising future, especially in high resolution applications. However, the limited performance due to the low dc gain of mechanical sensing element and the stability problem caused by phase-lag are always unavoidable. Previously, researches stabilized higher order electro mechanical SDM (EMSDM) systems...
In this work it is described the progresses carried out in the implementation of a wireless sensor network for seismic monitoring with possibility of access to the Internet via modem GSM/GPRS. The network is designed to minimize implementation and localization costs in order to deploy a large number of sensors in mesh topology in areas covering the civil structure to be monitored.
When tracking an extended object, traditional approaches exploit information only from measurements that are assumed to stem from the target, and discard observations assumed to have been generated elsewhere. However, the fact that these observations were received contains valuable information about where the target is not. This information, which is usually treated as clutter with little value, can...
We address the problem of robust instance detection in RGB-D image in the presence of noisy data, cluttering, partial occlusion and large pose variation. We extract contour points from the depth image, construct a Surface Oriented Traverse (SOT) feature for each contour point and further classify it as either belonging or not belonging to the instance of interest. Starting from each contour point,...
This paper presents a methodology to combine information from a sequence of RGB-D spherical views acquired by a home-made multi-stereo device in order to improve the computed depth images both in terms of accuracy and completeness. This methodology is embedded in a larger visual mapping framework aiming to produce accurate and dense topometric urban maps. Our method is based on two main filtering...
Distributed wireless networks often employ voting to perform critical network functions such as fault-tolerant data fusion, cooperative sensing, and reaching consensus. Voting is implemented by exchanging messages with a fusion center or just between the participants. However, the communication and delay overheads of message-based voting can be prohibitive when voting is frequent. Additional overheads...
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