scholarly journals Wavelet Based Simulation and Analysis of Single and Multiple Power Quality Disturbances

2019 ◽  
Vol 9 (2) ◽  
pp. 3909-3914 ◽  
Author(s):  
F. Jandan ◽  
S. Khokhar ◽  
Z. A. Memon ◽  
S. A. A. Shah

Improving power quality disturbance (PQD) detection and automatic classification has been a major concern ever since the emergence of sensitive non-linear devices. The role of distributed generation in a power system is the main source of PQDs. Short-term and long-term duration single and multiple complex PQDs are difficult to monitor and need higher accuracy and time. This paper presents the analysis of different and distinctive combinations of PQDs. Variety of single and multiple PQD samples are generated using Matlab environment conferring to IEEE STD 1159-2009. Such disturbance samples are accurately detected and analyzed from waveform patterns using multi resolution analysis based discrete wavelet transform. The generation of samples and detection lies in fact that it can allow the feature extraction process for the training/testing sample features for machine learning based automatic recognition of disturbance types.

The most common technique used for image processing applications is ‘The wavelet transformation’. The Discrete Wavelet Transform (DWT) keeps the time as well as frequency information depend on a multi resolution analysis structure, where the other classical transforms like Fast Fourier Transform (FFT), Discrete Cosine Transform (DCT) will not do that. Because of this feature, the quality of the repaired image is improved when comparing to the other transforms. To implement the DWT on a real time codec, a fast device needs to be targeted. While comparing with the other implementation such as PCs, ARM processors, DSPs etc, Field Programmable Gate Array (FPGA) implementation of DWT had better processing speed and costs were vey less. A Fast Architecture based DWT using Kogge Stone Adder is proposed in this paper where the coefficients of lifting scheme are calculated by using Shift adder and Kogge Stone Adder where other techniques used multiplier. The most important intention of the suggested technique is to use minimum calculation and limited memory. The simulation of the suggested design is dole out on the Xilinx 14.1 style tool and also the performance is evaluated and compared with the present architectures.


2019 ◽  
Vol 36 (3) ◽  
pp. 171-178 ◽  
Author(s):  
Katherina Y. Wellman ◽  
Padraic M. Dixon

Thirty-nine equine cheek teeth diagnosed as having anachoretic apical infections and also having occlusal fissure fractures, but without occlusal pulpar exposure, that had been orally extracted without causing occlusal damage and 10 control teeth were used in this study. The teeth were individually imaged by computed tomography, occlusally stained with methylene blue and visually reexamined, then sectioned subocclusally at 5 mm intervals until the fissure fractures could no longer be detected. A limited histological study was then performed on 7 apically infected and 5 control teeth. Standard computed tomography only detected 1 of 39 fissure fractures. Thirteen of the 39 stained teeth had subocclusal fissure fractures visually identified at approximately 6 mm beneath the surface, and in 9 of these 13 teeth the fissure fractures had deeper staining to a level immediately above or into a pulp horn, indicating a potential route for bacterial pulpitis. However, the current study cannot rule out the possibility that the extraction process, long-term formalin storage, or the processing of teeth may have allowed for deeper staining. Additionally, methylene blue may penetrate dental tissue more readily than bacteria can invade. Further studies on the potential role of fissure fractures in the etiopathogenesis of cheek teeth apical infection are warranted.


Author(s):  
Y Srinivasa Rao ◽  
G. Ravi Kumar ◽  
G. Kesava Rao

An appropriate fault detection and classification of power system transmission line using discrete wavelet transform and artificial neural networks is performed in this paper. The analysis is carried out by applying discrete wavelet transform for obtained fault phase currents. The work represented in this paper are mainly concentrated on classification of fault and this classification is done based on the obtained energy values after applying discrete wavelet transform by taking this values as an input for the neural network. The proposed system and analysis is carried out in Matlab Simulink.


Author(s):  
Bao Qin Wang ◽  
Gang Wang ◽  
Xiao Hui Zhou ◽  
Yu Su

In this paper, a simple method is given in order to construct an area preserving mapping from a developable surface M to a plane. Based on the area preserving projection, we give some important formulas on M, and define a multi-resolution analysis on L2(M). We provide the conditions to further discuss the continuous wavelet transform and discrete wavelet transform on developable surface. At the same time, we derived two-scale equations that the scaling function and wavelet function on developable surface satisfied, we also define and discuss the orthogonality, and several important theorems are given. Finally, we construct the numerical examples. The focus of this paper is the area preserving mapping that from developable surface M to a plane, and the discrete wavelet transform on developable surface.


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