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Whenever reliable transmissions are assured by retransmission mechanisms, higher packet error incur in additional energy consumption due to packet retransmissions, even though many monitoring applications can tolerate some loss in the quality of the received images. In fact, visual information retrieved from source nodes may have different relevancies for the applications, according to the desired...
When packets are transmitted over braided-paths in visual sensor networks some intermediate nodes may relay most part of the traffic, turning part or the entire network inactive when they run out of energy. Due to the nature of visual monitoring, source nodes may have different relevancies for the application, according to the desired monitoring tasks and the current sensors' poses and fields of view...
In this paper, a novel covariance spectrum sensing approach used in cognitive radio (CR) networks which is based on the dynamical stochastic resonance (SR) technique is proposed. When the optimal SR technique is introduced as the pre-processing method for the covariance-based detection and after it has been realized, it can increase the signal-to-noise ratio (SNR) of the primary user (PU) signal and...
In Machine-to-Machine (M2M) communications, machines are wirelessly connected to accomplish collaborative tasks without human intervention, and provide ubiquitous solutions for real-time monitoring. The real-time monitoring application is one of the killer applications for M2M communications, where M2M nodes transmit sensed data to an M2M gateway, and then the M2M gateway can have real-time monitoring...
The great diversity of mobile sensor networks (MSNs) has emerged in different networks, including vehicular ad-hoc networks (VANETs), underwater sensor networks (UWSNs), and wireless body area networks (WBANs), which provide ubiquitous solutions for real-time monitoring. To prolong the network lifetime of MSNs, energy conservation for mobile sensors needs to be taken into consideration while we design...
This paper investigates uniform distribution and Gaussian distribution effect on intrusion detection performance in wireless sensor networks (WSN). Deployed sensor number and sensing range of individual sensors on the intrusion distance are investigated for both the single-sensing and multiple-sensing cases, under the homogeneous sensing condition. Numerical simulations show that, the Gaussian distribution...
We propose a fast algorithm for solving the inverse problem of resolution enhancement (superresolution). Robustness is achieved by a non-linear regularizer and a method based on variable splitting is used to obtain an equivalent linear formulation. Special attention is paid to fast implementation using the Fourier transform. In particular, we show that a degradation operator (downsampling) can be...
In this paper, we propose a location-related strategy selection (i.e., to sensing or not?) to maximize the exploitation of spatial-temporal spectrum opportunity for cognitive vehicle radios. As the distance between a secondary transmitter (ST) and a primary transmitter (PT) varies, the ST adaptively switches its strategy selection, between a listen-before-talk (LBT) strategy and a constrained-talk-without-listen...
In opportunistic spectrum access (OSA), secondary radios (SRs) are allowed to access the channel whenever primary radios (PRs) are not transmitting. The PR's spectrum activities are normally assumed to be a 2-state continuous Markov on-off process which can be modeled as two independent exponential random variables. On the other hand, some simulations prefer using a 2-state discrete Markov chain....
To realize opportunistic spectrum access, spectrum sensing is applied to detect the presence of spectrum holes. If secondary radios (SRs) randomly or sequentially sense the channels until a spectrum hole is detected, significant amount of the scarce spectrum resource will be wasted, since SRs transmit only after a decision has been made. On the other hand, with the use of an intelligent predictive...
A new censoring cooperative spectrum sensing scheme in cognitive radio (CR) network is proposed in this paper, which is based on stochastic resonance (SR) technique and optimal censoring interval. The selection strategy for the optimal censoring interval is derived. The observations of the cooperative secondary users (SUs) whose statistics fall into the censoring interval are processed by SR system...
This paper analyses qualities of methods for testing dynamical parameters of Analog to Digital and Digital to Analog Converters using impulse signal. Damped Sine Wave signal will be used, as the source for these signals. Furthermore an example of analog realization the damped sine wave signal generator and its qualities are shown in this paper. The results will be compared with Sin Wave FFT test....
Traditional voltage sensing method has already been widely used for the synchronous rectifier. However, the parasitic parameters will cause the false turn-on and early turn-off problem. In this paper, the conception of zero-crossing noise filter is presented. By applying this filter to the synchronous rectifier, the false turn-on and early turnoff problem can be resolved. Only three passive components...
In this paper, a low-noise high-gain read-out circuit with a response time acceleration technique for high output impedance sensors is presented. In the readout circuits using a switched capacitor amplifier, the thermal noise can be greatly reduced if a reset noise component sampled at the charge summing node is canceled. Due to high output impedance of sensors the response time is large to achieve...
A deployment strategy of hierarchical structure wireless sensor network. (HSWSN) is studied, HSWSN are composed basic station (BS), relay devices (RNs) and sensors (SNs). In this paper, the mode of system and energy consumption are proposed, the deployment strategy especial relay devices is proposed, and some important such that energy consumption density (ECD), distribution probability of RN consumption...
In this paper, we propose Opportunistic Carrier Prediction (OCP) that jointly addresses exposed terminal and hidden terminal problems in wireless networks. OCP is based on the rationale that past interference information can be a good indicator for the outcome of future packet delivery. Each OCP sender maintains a summary of past interference information and opportunistically accesses the channel...
The transition behavior of an elastically-bossed layered plate under pretension in large deflection due to lateral load is studied. The nonlinear governing equation reduces to a modified Bessel equation for the lateral slope, following a linear consideration. Analytical solutions for the geometrical responses were developed and were found to be expressible in terms of both the first and the second...
In opportunistic spectrum access, a secondary radio (SR) periodically senses for a vacant channel to transmit. Common performance measures of the adopted sensing algorithm include missed detection and false alarm probabilities. However, minimal effort is made to incorporate the primary radio (PR) spectrum activities in the design. This paper models the errors arising from the mismatch between the...
A digital implementation of synchronous rectification (SR) driving scheme for LLC resonant converter is proposed in this paper. Compared with analog ones, digital implementation enables more intelligent and precise SR control, improving converter efficiency. In the proposed SR driving scheme, the drain to source voltage of synchronous rectifier on the secondary side is sensed, so that the paralleled...
A new driving method for SR is presented. By applying a zero-crossing noise filter to the MOSFET, the false-triggering of the SR can be effectively eliminated. Moreover, the resistor and the capacitor in the filter can be used as a compensator to solve the duty cycle loss issue caused by the trace inductance of the MOSFET package. Only three passive components are needed in the proposed filter which...
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