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State-of-the-art sensing methods only exploit three dimensions of the spectrum space: frequency, time and geography whereas the angle dimension, that is, spatial spectrum sensing has not been exploited well enough. In this paper, we apply the multiple signal classification (MUSIC) Angle of Arrival (AoA) estimation method into spectrum sensing. Note that MUSIC method needs to know the number of signals,...
State-of-the-art sensing methods mostly exploit spectrum holes (SHs) in conventional frequency, time, and geography dimensions, which can hardly satisfy the increasing throughput demand of CR networks. Meanwhile, the rapid development of multi-antenna technology makes the terminal obtain the angle recognition capability. Motivated by this, this paper analyzes SHs from the angle/space domain and design...
The minimum number of required sensors problem in sweep coverage, one of the important coverage problems in WSN, using a small number of mobile sensor nodes to satisfy both POI (Point of Interest) coverage and data delivery is a dynamic coverage problem. To find the minimum number of mobile sensor nodes with a uniform speed to guarantee sweep coverage was proved to be a NP-hard problem. In this paper,...
Currently, conventional indoor localization schemes mainly leverage WiFi-based or Bluetooth-based schemes to locate the users in the indoor environment. These schemes require to deploy the infrastructures such as the WiFi APs and Bluetooth beacons in advance to assist indoor localization. This property hinders the indoor localization schemes in that they are not scalable to any other situations without...
To ensure the effectiveness of ultra-high-frequency (UHF) method on the on-line monitoring and live detecting of partial discharge (PD) for the gas-insulated metal-enclosed switchgear (GIS), this paper proposes a field calibration method for the UHF PD detection sensors in GIS, which is based on the forward propagation coefficient in the microwave network theory. Firstly, on a full-scare test platform...
The spatial spectrum indicates the energy distribution in all directions. If we can get the spatial spectrum, then the spectrum holes in space are known. In spatial spectrum sensing of cognitive radio, an electronically steerable parasitic antenna receptor (ESPAR) divides the space into sectors which are accessed by directional beamforming on a time division basis. Hence, the energy at different direction...
In our view of the market of data, data should be sold at an agreed price, opened for free, or shared under agreed conditions after negotiation in order to increase, rather than decrease, data providers' business opportunities, as a result, decision makers and data analysts can be provided with data needed. In addition, knowledge and skills related to data analysis should be shared among data users...
According to the specific application of small low-cost UAVs (Unmanned Air Vehicles), an improved method integrating MEMS gyro, MEMS accelerometer and magnetometers is proposed. Firstly, according to the sensory measurements, navigation information including two sets of Euler angles and the triad of velocity can be acquired. Subsequently, a simplified state space equation without modeling the body...
In this paper, we introduce an improved self-adaptive localization algorithm based on DV-HOP for the node localization in wireless sensor network. We firstly divide the sensing area into several small regions according to the density of unknown nodes. Then, the beacon nodes are distributed within the sensing area in a reasonable manner, based on DV-HOP algorithm and combined with RSSI. The measured...
Strain-sensitive, conductive nanocomposite elastomer is an emerging MEMS material. Here, we present comprehensive characterization of contact resistance between nanocomposite elastomers and metal electrodes for different contact areas, applied forces, and contact metals. Further, we report new findings regarding the strain dependence of bulk resistance. These lead to important guidelines for designing...
Nanocomposite elastomer is an exciting, emerging class of materials for polymer MEMS sensors and actuators . It is made by mixing electrically conducting particles (e.g., carbon nanotubes) in regular, nonconducting elastomer (e.g., PDMS) beyond percolation limit. The bulk resistance of the polymer is a function of particle doping concentration and other parameters (e.g., applied stress). The electrical...
We report on the development of new elastomers and processes that utilize polymers such as PDMS, FSR (force sensitive resistor) polymer, MWCNT, and polyurethane to realize bioinspired sensors such as artificial haircells. In nature, haircell sensors are used by fish to sense flow, by spiders to sense vibration, and by some vertebrates for hearing and acoustics. An artificial haircell sensor is designed...
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