| 1. |
- Alqaysi, Hiba, et al.
(författare)
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Cost Optimized Design of Multi-Camera Domefor Volumetric Surveillance
- 2021
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 21:3, s. 3730-3737
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Tidskriftsartikel (refereegranskat)abstract
- A multi-camera dome consists of number ofcameras arranged in layers to monitor a hemisphere aroundits center. In volumetric surveillance,a 3D space is required tobemonitoredwhich can be achievedby implementing numberof multi-camera domes. A monitoring height is consideredas a constraint to ensure full coverage of the space belowit. Accordingly, the multi-camera dome can be redesignedinto a cylinder such that each of its multiple layers hasdifferent coverage radius. Minimum monitoring constraintsshould be met at all layers. This work is presenting a costoptimized design for the multi-camera dome that maximizesits coverage. The cost per node and number of squaremetersper dollar of multiple configurations are calculated using asearch space of cameras and considering a set of monitoring and coverage constraints. The proposed design is costoptimized per node and provides more coverage as compared to the hemispherical multi-camera dome.
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| 2. |
- Magno, M., et al.
(författare)
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A Bluetooth-Low-Energy Sensor Node for Acoustic Monitoring of Small Birds
- 2020
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Ingår i: IEEE Sensors Journal. - : Institute of Electrical and Electronics Engineers Inc.. - 1530-437X .- 1558-1748. ; 20:1, s. 425-433
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Tidskriftsartikel (refereegranskat)abstract
- Animals can generate sounds that serve a wide range of vital functions such as to defend themselves or their territories, to attract a partner, to maintain contact with other members of their social group, and to help themselves and their partner/group during navigation. Ethologists are interested in recording and analyzing these sounds, many of which are vocalizations. Advances in sensing and wireless technology permit today acoustic data acquisition and transmission in a wireless manner. In many applications, the wireless sensor needs to be placed on the animal's body and should be unobtrusive, light-weight, small, and long-lasting. This paper presents the design and development of an ultra-low power miniaturized and lightweight wireless sensor node for monitoring captive zebra finches. The node is designed to be worn with minimal effort by small-sized birds to collect, process, and send/receive data to/from a remote host via Bluetooth Low-Energy. The main feature of the developed node is the capability to stream compressed or uncompressed audio and temperature data continuously. Multiple nodes can monitor several birds simultaneously and acquire and transmit high-quality audio streams, one for each bird, with low audio interference. Due to the combination of low-power hardware and software techniques and technologies, the 1.4 g node achieves a lifetime of up to 24 h at 4 kHz sampling rate on a single zinc-air battery. Experimental results on birds confirm the functionality of the developed wireless node and the lifetime benefits of compression. © 2001-2012 IEEE.
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| 3. |
- Nnonyelu, Chibuzo Joseph, 1986-, et al.
(författare)
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On the Performance of L- and V-Shaped Arrays of Cardioid Microphones for Direction Finding
- 2021
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Ingår i: IEEE Sensors Journal. - : Institute of Electrical and Electronics Engineers (IEEE). - 1530-437X .- 1558-1748 .- 2379-9153. ; 21:2, s. 2211-2218
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Tidskriftsartikel (refereegranskat)abstract
- The L-shaped and V-shaped arrays of first-order cardioid microphones for direction finding are presented in this paper. A comparative study of the direction of arrival estimation performance of the arrays was carried out by analytically deriving, in closed-form, and comparing the Cramér-Rao bounds of an incident signal's direction-of-arrival (DoA) azimuth and polar angles for these arrays. The maximum-likelihood estimator is used to verify the correctness of derived bounds. This investigation reveals that for direction finding, the L-shaped array of cardioid microphones would generally outperform the V-shaped array of cardioid microphones in more sub-regions of the DoA polar-azimuth angle space. However, in regions where the V-shaped array of cardioid microphones outperforms the L-shaped array of cardioid microphone, the variance ratios are usually higher in favor of the V-shaped array.
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| 4. |
- Nnonyelu, Chibuzo J., Dr. 1986-, et al.
(författare)
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Two Cardioid Sensors in Perpendicular Colocation – Their “Spatial Matched Filter" Beam Steering
- 2024
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Ingår i: IEEE Sensors Journal. - : Institute of Electrical and Electronics Engineers (IEEE). - 1530-437X .- 1558-1748. ; 24:9, s. 15033-15045
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Tidskriftsartikel (refereegranskat)abstract
- Cardioid microphones/hydrophones have been commonplace in practical acoustics. Indeed, cardioid sensors are widely obtainable in retail as diverse commercial models produced by numerous manufacturers. A cardioid sensor has a highly directional gain pattern of α + (1 - α)cos(γ), where α represents the sensor’s cardioidicity index, and γ denotes the impinging wavefront’s spatial angle incident upon the cardioid sensor’s axis. This paper is the first in the open literature to investigate the “spatial matched filter" beam-pattern obtainable from two such cardioids that lie in perpendicular colocation. Such a bi-axial cardioid pair is worth investigating because (i) their diverse orientation successfully realizes two-dimensional (azimuth-polar) directivity with only two sensors, (ii) their spatial colocation is advantageous for physical compactness and also for the decoupling of the data’s time-and-frequency dimensions from the azimuth-and-elevation directional dimensions to simplify signal-processing computation. This present investigation, however, uncovers that this beam-pattern generally peaks away from the nominal preset “look direction", but algorithmic mitigation is made possible by this paper’s pre-steering formula derived here to judiciously pre-adjust the beamformer’s nominal “look direction". Further action-able insights are provided in this paper for the hardware system engineer to pre-select the sensors’ cardioidicity index α for maximum steerability and freedom from sidelobes.
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| 5. |
- Verdel, Nina, et al.
(författare)
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Reliability and validity of running step rate derived from a novel wearable Smart Patch
- 2024
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Ingår i: IEEE Sensors Journal. - : IEEE. - 1530-437X .- 1558-1748. ; 24:9, s. 14343-14351
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Tidskriftsartikel (refereegranskat)abstract
- A novel, wearable, stretchable Smart Patch can monitor various aspects of physical activity, including the dynamics of running. However, like any new device developed for such applications, it must first be tested for validity and reliability. Here, we compare the step rate while running on a treadmill measured by this smart patch with the corresponding values obtained with the ”gold standard” OptoGait, as well as with other devices commonly used to assess running dynamics, i.e., the MEMS accelerometer and commercially available and widely used Garmin Running Dynamic Pod. The 14 healthy, physically active volunteers completed two identical sessions with a 5-minute rest between. Each session involved two one-minute runs at 11 km/h and 14 km/h separated by a one-min rest. The major finding was that the Smart Patch demonstrated fair to good test-retest reliability. The best test-retest reliability for the Running Pod was observed in connection with running at 11 km/h and both velocities combined (good and excellent, respectively) and for the OptoGait when running at 14 km/h (good). The best concurrent validity was achieved with the Smart Patch, as reflected in the highest Pearson correlation coefficient for this device when running at 11 or 14 km/h, as well as for both velocities combined. In conclusion, this study demonstrates that the novel wearable Smart Patch shows promising reliability and excellent concurrent validity in measuring step rate during treadmill running, making it a viable tool for both research and practical applications in sports and exercise science.
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