219 research outputs found
Cutting tool tracking and recognition based on infrared and visual imaging systems using principal component analysis (PCA) and discrete wavelet transform (DWT) combined with neural networks
No full textThe implementation of computerised condition monitoring systems for the detection cutting tools’ correct installation and fault diagnosis is of a high importance in modern manufacturing industries. The primary function of a condition monitoring system is to check the existence of the tool before starting any machining process and ensure its health during operation. The aim of this study is to assess the detection of the existence of the tool in the spindle and its health (i.e. normal or broken) using
infrared and vision systems as a non-contact methodology. The application of Principal Component Analysis (PCA) and Discrete Wavelet Transform (DWT) combined with neural networks are investigated using both types of data in order to establish an effective and reliable novel software program for tool tracking and health recognition. Infrared and visual cameras are used to locate and track the cutting tool during the machining process using a suitable analysis and image processing algorithms. The capabilities of PCA and Discrete Wavelet Transform (DWT) combined with neural networks are investigated in recognising the tool’s condition by comparing the characteristics of the tool to those of known conditions in the training set. The experimental results have shown high performance when using the infrared data in comparison to visual images for the selected image and signal processing algorithms
RDLS-SS-DWT v. 0.9
No full textThis fileset contains the implementation of RDLS-DWT and SS-DWT in JPEG 2000 (RDLS-SS-DWT v. 0.9), which was used in a research described in: R. Starosolski, “Application of reversible denoising and lifting steps to DWT in lossless JPEG 2000 for improved bitrates,” Signal Processing: Image Communication, Vol. 39, Part A, pp. 249-63, DOI: 10.1016/j.image.2015.09.013, 2015 and R. Starosolski, “Skipping selected steps of DWT computation in lossless JPEG 2000 for improved bitrates,” submitted. This software is intended for research purposes only; it is provided "as is"; author makes no warranty of any kind, either express or implied, with respect to this software. <br
An efficient VLSI implementation of distributed architecture for DWT
No full textThis paper proposes an efficient and simple architecture for 9/7 Discrete Wavelet Transform based on Distributed Arithmetic. To derive new proposed architecture, we consider the periodicity and symmetry of DWT to optimize the performance and reduce the computational redundancy. The inner product of coefficient matrix of DWT is distributed over the input by careful analysis of input, output and coefficient word lengths. In the coefficient matrix, linear maps are used to assign the necessary computation to processing elements in space domain. Moreover, the proposed architecture has regular data flow, and low control complexity. The result is a low hardware complexity DWT processor for 9/7 transform, which allows two times faster clock than the direct implementation. This design is very suitable for image compression systems, e.g., JPEG2000 and MPEG4.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000244125600076&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Artificial IntelligenceEngineering, Electrical & ElectronicImaging Science & Photographic TechnologyEICPCI-S(ISTP)
A memory-saving system including DWT and EC for jpeg2000 implementation
No full textIn this paper, a new system including Discrete Wavelet Transform (DWT) and Entropy Coder (EC) is presented for JPEG2000 implementation. The system accomplishes a seamless connection between DWT and EC. To reach the goal, an EC-based DWT scheme is proposed, and a new EC architecture is designed that encodes three code-blocks concurrently. The system reduces the memory requirement significantly. Compared to the QCB-DWT scheme, more than 72 percent of memory is removed. And it is a high speed encoding system, able to encode 720x576 video more than 40 frames per second at 54MHz clock frequency.Computer Science, Artificial IntelligenceComputer Science, Information SystemsComputer Science, Software EngineeringImaging Science & Photographic TechnologyRadiology, Nuclear Medicine & Medical ImagingEICPCI-S(ISTP)
A BLIND VIDEO WATERMARK DETECTION METHOD BASED ON 3D-DWT TRANSFORM
No full textIn this paper, we propose a new blind video watermark detection method which is based on 3D-DWT transform. We find that the coefficients in the high frequency band of temporal wavelet transform (TWT) are nearly orthogonal to the normally-distributed watermark, which is the basis of our proposed extraction method. The watermarking procedure is similar to the former 3D-DWT method, first 2D-DWT in the spatial domain, then 1D-DWT in the temporal domain (TWT). The difference is that we do not use the low frequency band in the 1D-DWT procedure, for the property of the TWT high frequency band that we have found in the detection procedure. We also propose to use two zero-mean normally-distributed watermarks in embedding to avoid block effects. Finally, an absolute value detection scheme is proposed. Using this scheme our scheme can resist frame dropping attack and temporal frame averaging attack, because the TWT high frequency band reflects the changing parts along the temporal axis.Engineering, Electrical & ElectronicImaging Science & Photographic TechnologyEICPCI-S(ISTP)
Coasts in Peril? A shoreline Health Perspective
No full textMost assessments of coastal vulnerability are undertaken from the perspective ofthe risk posed to humans, their property and activities. This anthropocentric view is based on widespread public perception (a) that coastal change is primarily a hazard to property and infrastructure and (b) that sea defenses (whether soft or hard) are required to mitigate and eliminate coastal hazards. From the perspective of coastal ecosystems, such a view is both perverse and damaging. In this paper we presentan alternative approach to coastal assessment that centers on the physical integrity of the coast and its associated ecosystems both now and in the near-future. The shoreline health approach represents a new paradigm for coastal management and is intended to provide a much-needed ecosystem perspective. Its premise is to categorizecoasts on the degree to which their ability to function morphodynamically has been compromised by human intervention. We present an expert assessment approach involving five categories that range from “Good Health” (with “Health Warning” and “Minor Wounds” sub-divisions), through “Minor Injury,” “Major Injury,” “On Life Support” to “Deceased.” We illustrate the concept using tabulated examples of each category from cliffed, clastic and delta coasts and demonstrate its utility through two applications.This approach has the potential to quantify the degree to which coastal ecosystems have been damaged and to focus attention on the cumulative impact of human activities on coastal ecosystems
Ducted wind turbines revisited: A computational study
No full textDucted Wind Turbines (DWTs) are one of the many concepts that have been proposed to improve the energy extraction from wind in comparison to bare wind turbines. In reviewing the DWT studies, investigations based on the combined use of theoretical, computational, and experimental techniques have been presented. Although indicated in these studies that the power output of wind turbines can be significantly increased by using surrounding ducts, the factors influencing this power increase, like the duct shape, augmentation add-on’s and yawed inflow conditions, need further investigation. These topics have been addressed in this doctoral thesis. The study presents a computational investigation of DWTs, employing two-dimensional and three-dimensional CFD simulations. To this intent, solutions obtained using panel, RANS, URANS and LB-VLES methods are shown. For reliable solution accuracy, verification and validation assessments are performed when possible. Through parametric investigation, it is found that the aerodynamic performance of the DWT can be improved by increasing the duct cross-section camber and a correct choice of turbine thrust force coefficient, whilst maintaining the same duct-exit-area ratio. The aerodynamic performance improvement for a DWT directly corresponds to the dimensionless duct thrust force coefficient. Flow analysis showed that flow separation when detected inside of the duct, reduces the duct thrust force coefficient and ultimately the aerodynamic performance of the DWT model. In an effort to further improve on the aerodynamic performance of the DWT, the effect of multi-element ducts and Gurney flap on the existing DWT models are investigated. The aerodynamic performance improvement with multi-element ducts strongly depends on the installation settings of the secondary duct element with respect to the primary DWT geometry. On the other hand, a Gurney flap retrofitted at the trailing edge of the duct improves the aerodynamic performance of the DWT model by delaying inner duct wall flow separation, thus increasing the mass flow rate at the turbine. Finally, the effects of yawed inflow condition on the aerodynamic and aeroacoustic performance of DWT models are studied in detail. The analysis showed that DWTs can demonstrate yaw insensitivity up to a specific yaw angle. The yaw insensitivity for the DWT model, however, strongly depends on the aerodynamic mutual interaction between the duct and turbine, which changes with the duct geometry, turbine configuration and yaw angle. While assessing the aeroacoustic performance of the DWT models, it is found that the DWT model xiii xiv Summary with highly cambered duct cross-section generates higher broadband noise levels, which results from the turbulent flow structures convecting along the surface of the duct.Wind Energ
Real Time Implementation of Image Enhancement Based on 2D-DWT
No full textAbstractDigitization of images usually suffer from poor image quality, lack of contrast and presence of shading and artifacts, to improve quality of image, especially in effectiveness or attractiveness enhancement is required, The main objective is to enhance the color image by converting the RGB value of each pixel of the original image to HSV then 2D-DWT applied to the luminance value of V component. It decomposes the original image into four sub bands. The low frequency sub band is smoothened by using geometric mean filter. Then the IDWT applied with new low frequency and other sub bands. The enhanced V is combined with H and S are converted back into RGB. The experimental results vividly displays the proposed algorithm is efficient to enough to remove the noise resulting good enhancement and then achieved increased value of PSNR and reducing value of MSE. The above proposed scheme implemented in Xilinx Spartan-6 FPGA for increasing the speed greatly and reduces the size of the needed storage space
Using Benford's Law for wavelet coefficients to differentiate images: Het toepassen van Benford's Law op wavelet coëfficiënten om afbeeldingen te onderscheiden
No full textThis thesis explores the application of Benford's Law to wavelet coefficients derived from the Discrete Wavelet Transform (DWT) of images, aiming to provide a novel method for image differentiation. The study focuses on the DWT, specifically utilizing Haar and Daubechies wavelets, to decompose an image into approximation and detail coefficients. Benford's Law, predicting the frequency distribution of leading digits in natural datasets, is applied to the detail coefficients. The research investigates whether this approach can differentiate natural images from other genres, such as paintings or cartoons. The thesis provides a comprehensive understanding of wavelets, the DWT, and signal decomposition, followed by an introduction to Benford's Law and its applications. The final part involves applying Benford’s Law to the DWT coefficients of different image genres, analyzing the results, and discussing further research.Applied Mathematic
RETRACTED: Optimization of the energy efficiency operational indicator for M/V NSU JUSTICE 250,000 DWT by grey relational analysis method in Vietnam
No full text At the request of the Journal Editor and the Publisher, the following article has been retracted. Tran TA, Optimization of the energy efficiency operational indicator for M/V NSU JUSTICE 250,000 DWT by grey relational analysis method in Vietnam, Proc IMechE, Part M: J Engineering for the Maritime Environment, First Published December 26, 2017, DOI: 10.1177/1475090217748756 Following investigation into this article, it has been determined that the article includes major overlap with a previously published article by the same author; Tran TA, Optimization of the Energy Efficiency Operational Indicator for M/V NSU JUSTICE 250,000 DWT by Grey Relational Analysis Method in Vietnam, J Marine Sci Res Dev 2017, 7:232, DOI: 10.4172/2155-9910.1000232 [Accessed: 4th January 2018] </jats:p
- …
