The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In recent years, service robots have advanced toward having to the ability to move autonomously in an environment in which they co-exist with humans. Thus, the robots must engage in obstacle avoidance to arrive at their goal point. In our previous research, we developed the artificial potential based method that the robot to plans an effective path simulating pedestrian characteristics by gently changing...
Air traffic and on-board data access services are expected to have tremendous growth, possibly even exponentially in the near future. In order to meet these challenges, Orthogonal Frequency Division Multiplexing (OFDM) can be deployed to enable the increased usage of broadband services on-board. The Doppler effect is one of the major issues in implementing OFDM modulation in aeronautical satellite...
Nutrition is an important factor in the prevention and treatment of many diseases. Nutrition is a key factor for obesity, which is a risk factor for cardio-vascular diseases, type-2 diabetes and even cancer. Many non-communicable diseases require patients to keep track of nutrition accurately. Diabetes type-2 and type-1 require tracking carbohydrate intake accurately. However, keeping track and even...
First, the received signal strength indications (RSSIs) of the three tags on a triangular apparatus surrounding a target human (TH) are read by two perpendicular antennas with one reader. These 6 RSSIs and their corresponding pose and the azimuth angle of the TH with respect to the autonomous guided vehicle (AGV) or antenna are attained. Since the relations of these pairs of input and output are nonlinear,...
Due to continuous and unplanned urbanization, biases and probability of occurrences of non-line-of-sight (NLOS) errors can be drastically enlarged in macro-cellular smart urban environments. This paper presents a new robust estimation approach to mobile tracking improvements based on adequately tackling NLOS errors. To cover the dynamics of a mobile station, we cast a wireless localization problem...
It is shown that the excessive inhalation of PM (Particulate Matter) 2.5 will seriously affect the health of human. Many countries have deployed various detectors for air pollution in order to report concentration of PM2.5 to show how much seriousness of air pollution is. But, what more important is how much PM 2.5 has been inhaled by people anytime and anywhere. Therefore, in this paper, we propose...
In this paper, the authors proposes a easy calibration of DOD-based BLE beacon system for an indoor localization application. By the proposed calibration method, we can easily recognize the orientation and location of the beacon even though the beacons are roughly installed. The method uses DOD calculated from RSSI of received beacon signals and sensor information of the mobile handset for calibration...
A large number of web databases are hidden behind form-based interfaces (consisting of interface components such as textboxes, drop-down boxes, etc) for users to enter their desired values in a search query. Form-based interfaces are not always easy to use and error-prone on mobile devices, mainly because of limitations such as smaller screen, trickier text input, etc. We build MobiFace which is a...
Mobile Broadband (MBB) access networks are becoming more and more used worldwide, and the devices adopted to access them are increasing in number and complexity (smart-phones, mobile hotspots, vehicular infotainment systems). The highly dynamic nature of such scenarios calls for continuous monitoring and measurement of the network. To this aim, the Available Bandwidth is a performance metric of the...
Free-space radiowave propagation model, used in short-range EMC system analysis, is inadequate for the reactive near-field zone in the radiating source vicinity. It results in errors when the electromagnetic background intensity is being analyzed in cases with high terrestrial density of mobile transmitters, capable to be found nearer to an observation point at ranges, comparable with radius of this...
Spectral efficiency and capacity of Land Mobile Satellite (LMS) systems can be enhanced by using MIMO (Multiple Input Multiple Output). Polarization diversity is an efficient technique to realize MIMO in LMS communications. Polarization diversity employs different polarization to realize multiple independent propagation paths. Dual polarized antennas offer a space and cost effective alternative compared...
In this paper we analyze the use of tight frames for the problem of localizing a source from noisy time-difference of arrival measurements. Based on the Fisher information matrix, we show that positioning the sensor network according to a tight frame that also obeys some internal symmetries provides the best average localization accuracy. We connect our result to previous approaches from the literature...
Location-awareness plays an important role in Wireless Sensor Networks (WSNs) by aiding in tasks such as packet routing, event mapping, and energy savings. The use of Global Positioning System (GPS) on sensor nodes is not always viable due to a number of issues, e.g., power constraints. Location estimation solves the problem of computing sensor node positions by using information from devices that...
In this paper, we investigate the Bayesian filtering problem for discrete nonlinear dynamical systems which contain random parameters. An augmented cubature Kalman filter (CKF) is developed to deal with the random parameters, where the state vector is enlarged by incorporating the random parameters. The corresponding number of cubature points is increased, so the augmented CKF method requires more...
Modeling and filtering of a mobile object stochastic trajectory on the basis of fractal Wiener process taking into account the Hurst indicator are offered. For numerical realization of this processes the wavelet based decomposition is used. The peculiarities of trajectory parameters estimation by using Kalman filter and the wavelet algorithm are investigated. The illustrating examples are given.
To deal with the distributed estimation for mobile sensor networks with switching topologies, an algorithm of the weighted average consensus-based cubature Kalman filtering is proposed by combining the advantages of the cubature Kalman filtering in information form and consensus algorithm. On the basis of the predecessors research work, the sufficient condition is presented for ensuring the weighted...
This paper investigates direct beamformer estimation in dynamic time division duplexing (TDD) system with the objective of weighted sum rate maximization. For a given TDD frame, base stations (BS) are allocated to either uplink or downlink based on the instantaneous traffic state. The weighted sum mean-squared error minimization framework is used to obtain the decentralized iterative solution for...
Channel estimation is one of the most important parts in current mobile communication systems. Among the huge contributions in channel estimation studies, the discrete Fourier transform (DFT)-based channel estimation has attracted lots of interests since it can not only be easily implemented but also have acceptable performance in practical systems. In this paper, we propose an improved DFT-based...
On the base of variational method, the new numerically effective procedures of echo-signals parameters estimation in passive coherent radar systems have been developed. These procedures are suitable for mobile objects echo-signals detection and their parameters estimation in real time.
In this paper, we investigate the performance of mobile vehicle positioning based on signal propagation delay estimation in the uplink case for a realistic propagation environment. In order to optimize the ranging performance, we introduce a parametric waveform. This waveform contains a scalar parameter for adjusting the distribution of the available signal power over the frequency. The optimization...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.