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Renewable energy sources are quickly becoming incorporated into increasingly distributed electrical utility grids. An ever present issue when interfacing these sources is that of harmonic distortion reduction at the inter-tie point. Presented in this paper is the modeling and analysis of a rarely employed technique for harmonic reduction using synchronized phase shifted parallel PWM inverters with...
Neural networks (NN) have been widely used for electricity forecasting, but some difficulties are still found. One of those difficulties is in choosing the optimal network parameter, which are strongly important to obtain accurate result. ldquoTrial and errorrdquo commonly used to set the parameter is ineffective in terms of processing time and the accuracy. In this paper, Taguchi method is employed...
This work lays out our investigation into the non-invasive, automatic measurement of blood pressure. We have investigated the use of a thermal camera to detect changes in surface temperature due to the pulse in the radial and ulner arteries and then moved on to detecting the same pulse using a low-cost thermistor. Our preliminary results presented here indicate that the pulse is indeed detectable...
For the better understanding of antenna and electromagnetic (EM) field theory and measurement, it is important to perform studies within an echo free indoor environment called anechoic chamber. Installing of such anechoic chamber involves a substantial large investment both financially and in physical space. Therefore, sometimes it is difficult to establish this chamber for an educational or research...
In this paper, we present a simulation platform to evaluate the performance of the limited-perimeter vector matching (LVM) fault localization protocol for all-optical networks. Through simulation results, we show that the LVM protocol can achieve excellent performance in terms of fault localization time while maintaining the maximum-level transparency of all-optical networks. This paper includes simulation...
In this paper we introduced a workload characterization study of the most popular video sharing service, YouTube, on the Web 2.0. For approximately a two-month period we collected the information of more than 17,000 video files and investigated the file attributes and popularity characteristics of YouTube. Since YouTube is considered as a huge video library, its access pattern has an important impact...
This paper presents a novel and efficient technique for extracting the most common stationary power quality disturbances in distribution systems. The new technique depends on new recursive implementation of the digital second-order linear filters. The proposed extraction technique is accurate and simple. In addition, it can be used to set a generalized compensating strategy for mitigating the most...
Developing and improving people surveillance in public areas has been a topic of interest over past several years. A novel hybrid visual tracking system for event detection and people tracking is proposed in this paper. Our surveillance system consists of a calibrated stationary and a pan, tilt, and zoom (PTZ) camera. The stationary camera has a wide field of view, and it detects global events. The...
The CN tower is a transmission hub and an instrumented tower for the measurement of the lightning return stroke current derivative. The recorded data are corrupted by different kinds of noise, and need to be denoised for accurate determination of the lightning return-stroke current waveform parameters. A new divide-and-conquer denoising approach that imitates the basis pursuit method and the Newton-Raphson...
We investigate blind detection, i.e. detection assuming the absence of instantaneous channel state information (CSI) and a statistical channel description at the receiver, of on-off keying (OOK) in a free-space optical (FSO) system. Using an observation window encompassing many consecutive independent bits, our blind detector capitalizes on the fact that the atmospheric turbulence is constant over...
In this paper, we present a diversity gain analysis for free-space optical (FSO) diversity systems operating in log-normal atmospheric turbulence channels. We consider a multi-input multi-output (MIMO) system and two decode-and-forward (DF) relay-assisted systems based on either serial (i.e., multi-hop transmission) or parallel (i.e., cooperative diversity) configurations. We adopt the recently introduced...
As a popular non-destructive test, acoustic emission (AE) has been widely used in many physical and engineering fields such as leak detection and pipeline inspection. Among those applied AE tests, a common problem is to extract the physical features of the ideal events, so as to detect similar signals. In acoustic signal processing, those features can be represented as joint time-frequency distribution...
A wireless network consisting of a large number of small sensors with low-power transceivers can be an effective tool for gathering data in a variety of environments. The data collected by each sensor is communicated through the network to a single processing center that uses all reported data to determine characteristics of the environment or detect an event. The communication or message passing...
In this paper we investigate the performance of the parity bit selected direct sequence spread spectrum (DS-SS) system using log likelihood ratio (LLR). In this system information bits are convolutionally encoded prior to being used in the parity bit selected DS-SS system. Reliability of the detected bits in the receiver is calculated in the form of LLRs and then used as the input of a soft input...
In the districts where solar energy and wind energy are naturally complementary, the application of wind-solar hybrid generation systems (WSHGS) can reduce the storage capacity of batteries and the total cost of the system compared with stand-alone PV or wind generation system. This paper presents a cost-effect controller system for 1 kW to 5 kW WSHGS with low DC voltage input (24 V DC or 48 V DC)...
In this paper we consider nonparametric power spectral density (PSD) estimation. We use finite length observed data not only to estimate the PSD by one of the existing periodogram estimators, but also to estimate the mean square error (MSE) in PSD estimation. Minimizing this criterion provides the optimum window length for the Blackman-Tukey approach. It can also provide extra adaptive window for...
In CDMA packet transmission, it is customary to start each packet with a preamble consisting of pseudo-random (PN) code with no data modulation. The preamble facilitates receiver acquisition of the spreading code alignment and this is essential for decoding the spread spectrum signal. Since packets are short, matched filters are employed to provide rapid acquisition and, in this case, we use a segmented...
The paper discusses a DSTATCOM topology for compensating ac loads in the three-phase, four-wire systems as well as supplying dc loads from its dc link. Its state space modeling is presented. The transient response of the compensator is very important while compensating dynamically varying loads. Any change in the load affects the dc link voltage directly. Generally, a closed loop proportional integral...
This paper presents a comparison between three different approaches to model the random operation of generation units in power networks for reliability studies. Monte Carlo simulation method is integrated with each of the proposed approaches to calculate the average power not supplied in a given system. The obtained results from each approach are compared to their corresponding values if obtained...
Wind energy is promising with no fuel cost and zero greenhouse gas emissions; however, its intermittent and volatile nature has added much to operation burdens and thus a low penetration level in short-term or spot market. On the one hand, the power system operator is facing increased spinning reserve and generation uncertainty; on the other hand, the wind independent power producer (IPP) is subject...
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