This paper presents a relay selection scheme for a multiple relayed free-space optical (FSO) communication network. The considered FSO network consists of two non line-of-sight terminal nodes and multiple two-way rela...
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ISBN:
(纸本)9781479984374
This paper presents a relay selection scheme for a multiple relayed free-space optical (FSO) communication network. The considered FSO network consists of two non line-of-sight terminal nodes and multiple two-way relays (TWR). In order to establish a communication link between the terminal nodes, two TWRs are selected using partial relay selection protocols. The partial relay selection protocols reduce the channel state information requirements of the system. Further, by using two relays, the advantages of cooperative diversity are achieved. The system performance is evaluated in terms of outage probability, considering an optical channel that is affected by atmospheric turbulence induced fading and pointing errors. Further, the numerical results demonstrate that system performance can be significantly improved by using the proposed relay selection scheme.
In this paper, the genetic algorithm is used to improve the performance of fractional order lowpass filters with Butterworth approximation. This improvement is obtained by using the coefficient optimization and suitab...
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In this paper, the genetic algorithm is used to improve the performance of fractional order lowpass filters with Butterworth approximation. This improvement is obtained by using the coefficient optimization and suitable scaling to approximate the ideal frequency response. Further, the error analysis of the designed and the existing filters with the performance of ideal ones is given to see the effectiveness of this optimization technique in the improvement of performance of designed filters over the existing filters in both, the passband and the stopband.
Due to the absence of appropriate mathematical methods, fractional order dynamic systems were studied only marginally in both theory and practice. In this paper, continuous-time and discrete-time approximations of hal...
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Due to the absence of appropriate mathematical methods, fractional order dynamic systems were studied only marginally in both theory and practice. In this paper, continuous-time and discrete-time approximations of half integrator have been analyzed and compared. An approach for the realization of half integrator is also presented. MATLAB simulation results are presented and comparisons performed with the ideal continuous-time domain half integrator. Analog Realizations of some of the s-domain models has also been discussed. Discrete Realizations of the z-domain models have been developed and results compared with the ideal continuous-time domain models.
This paper presents an intelligent diagnosis technique for wind turbine imbalance fault identification based on generator current signals. For this aim, Probabilistic Neural Network (PNN), which is powerful algorithm ...
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This paper presents an intelligent diagnosis technique for wind turbine imbalance fault identification based on generator current signals. For this aim, Probabilistic Neural Network (PNN), which is powerful algorithm for classification problems that needs small training time in solving nonlinear problems and applicable to high dimension applications, is employed. The complete dynamics of a permanent magnet synchronous generator (PMSG) based wind-turbine (WTG) model are imitated in an amalgamated domain of Simulink, FAST and TurbSim under six distinct conditions, i.e., aerodynamic asymmetry, rotor furl imbalance, tail furl imbalance, blade imbalance, nacelle-yaw imbalance and normal operating scenarios. The simulation results in time domain of the PMSG stator current are decomposed into the Intrinsic Mode Frequency (IMF) using EMD method, which are utilized as input variable in PNN. The analyzed results proclaim the effectiveness of the proposed approach to identify the healthy condition from imbalance faults in WTG. The presented work renders initial results that are helpful for online condition monitoring and health assessment of WTG.
In the modern day world air pollution has been a major concern for various environmental diseases. High traffic density, electricity production, and expanding commercial and industrial activities have increased air po...
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In the modern day world air pollution has been a major concern for various environmental diseases. High traffic density, electricity production, and expanding commercial and industrial activities have increased air pollution in an unpredictable manner. Thus, the forecast of air pollution can be used as an advisory to establish strategies and corrective measures particularly in case of higher air pollution levels. In view of this, in this work we investigate an application of Modified Particle Swarm Optimization (MPSO) to train ANFIS (Adaptive Neuro Fuzzy Inference System) for the efficient prediction of two major air pollutants namely, Sulphur dioxide (SO 2 ) and Ozone (O 3 ) in New Delhi. The results obtained are then compared with the traditional gradient based method normally used for training ANFIS. The comparison between the two was based on three performance indices, namely MSE (Mean Squared Error), RMSE (Root Mean Squared Error) and MAD (Mean Absolute Deviation). For SO 2 prediction MSE, RMSE and MAD of 0.110, 0.331 and 0.932 were obtained using the proposed method against 0.117, 0.342 and 1.03 respectively using the traditional method. Similarly for O 3 prediction, MSE, RMSE and MAD of 0.837, 0.700 and 2.49 were obtained against 0.878, 0.812 and 2.93 respectively. These results clearly indicate that ANFIS trained using MPSO is far better at generalizing, achieving higher accuracy for the prediction of SO 2 and O 3 air pollutants.
In this paper, we present the performance analysis of a Power Line Communication (PLC) system over log-normal fading channel assuming binary phase shift keying modulation scheme. The channel is also corrupted by addit...
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ISBN:
(纸本)9781467373104
In this paper, we present the performance analysis of a Power Line Communication (PLC) system over log-normal fading channel assuming binary phase shift keying modulation scheme. The channel is also corrupted by additive impulsive noise and background noise. We derive the probability density function ( p.d.f.) of the noise and using it, we find the closed form expressions for the bit error rate (BER) and outage probability. Finally, the numerical results are presented.
The aim of the present work is to pick and place an object with the help of robotic manipulator using computer vision. Real time object detection is achieved using a camera to capture the image in the region of intere...
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The aim of the present work is to pick and place an object with the help of robotic manipulator using computer vision. Real time object detection is achieved using a camera to capture the image in the region of interest (ROI). 2-D correlation between the object and captured image, along with image processing techniques, locates the object position. The pixel coordinates are then converted to real time distance coordinates. The object location is conveyed to the robotic arm with the help of software instructions and required operation of pick/place is performed. The object is successfully located and grabbed by the robotic arm, provided the relative position of the robotic arm and the camera is fixed. The method uses two-dimensional image analysis in place of three-dimensional object detecting techniques. Hence the proposed algorithm is simple, requires less memory space, does not require any filter, reduces the instruction set and has high accuracy.
For years, statistical uncertainty in high-frequency circuits had been analyzed by post-processing data from repetitive simulations. Not surprisingly, this approach is extremely time consuming and hardly within the ti...
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ISBN:
(纸本)9781479919949
For years, statistical uncertainty in high-frequency circuits had been analyzed by post-processing data from repetitive simulations. Not surprisingly, this approach is extremely time consuming and hardly within the time constraints of a typical engineering design cycle. Recently, several new computational algorithms have been presented, which offer a fresh perspective to this old problem. This paper emphasizes approaches that stem from the polynomial chaos expansion method along with promising hybrid methods that can lead to efficient multi-parametric uncertainty quantification solvers.
作者:
M.E. El-HawaryAzad Hind FaujMarg
Sector- 3 Netaji Subhas Institute of Technology Dwarka New Delhi India UESTC
School of Computer Science & Engineering Chengdu China
Presents the introductory editorial for this issue of the publication.
Presents the introductory editorial for this issue of the publication.
Text Classification enhances the accessibility and systematic organization of the vast reserves of data populatingthe world-wide-web. Despite great strides in the field, the domain of context driven text classificatio...
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Text Classification enhances the accessibility and systematic organization of the vast reserves of data populatingthe world-wide-web. Despite great strides in the field, the domain of context driven text classification provides fresh opportunities to develop more efficient context oriented techniques with refined metrics. In this paper, we propose a novel approach to categorize text documents using a dual lexical chaining technique. The algorithm first prepares a cohesive category-keyword matrix by feeding category names into the WordNet and Wikipedia ontology, extracting lexically and semantically related keywords from them and then adding to the keywords by employing a keyword enrichment process. Next, the WordNet is referred again to find the degree of lexical cohesiveness between the tokens of a document. Terms that are strongly related are woven together into two separate lexical chains; one for their noun senses and another for their verb senses, that represent the feature set for the document. This segregation enables a better expression of word cohesiveness as concept terms and action terms are treated distinctively. We propose a new metric to calculate the strength of a lexical chain. It includes a statistical part given by Term Frequency-Inverse Document Frequency-Relative Category Frequency (TF-IDF-RCF) which itself is an improvement upon the conventional TF-IDF measure. The chain's contextual strength is determined by the degree of its lexical matching with the category-keyword matrix as well as by the relative positions of its constituent terms. Results indicate the efficacy of our approach. We obtained an average accuracy of 90% on 6 categories derived from the 20 News Group and the Reuters corpora. Lexical chaining has been applied successfully to text summarization. Our results indicate a positive direction towards its usefulness for text classification.
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