3 research outputs found
Lossless Color Image Compression using Double Level RCT in BBWCA
No full textAbstractA new lossless image compression scheme for natural color images which is based on double level Reversible Color Transform(RCT) and Bi-level Burrows Wheeler Compression Algorithm(BBWCA) is proposed. The first level RCT from RGB to HSV provide higher reduction in number of unique hue components, thus gives higher compression in case of natural images. The first level RCT followed by the second level RCT from HSV to YUV helps to yield small number of unique Y component values. DC level shifting and twos complement operation will be applied as preprocessing steps to second level RCT. The result of double level RCT is used as the input to BBWCA, in which row-wise BWT followed by column-wise BWT is applied. The compressed image data is formed by using move-to-front(MTF), Run-length-encoding and Entropy coding. The proposed method using double level RCT with BBWCA results in high compression by taking advantage of reduction in hue components of natural images. Among the different color space compared, the proposed method achieves better compression and is well suited for small and large size natural images. Proposed method make use of a double level RCT on the existing BBWCA algorithm and resulted in improving the compression ratio by 46 percentage
Mathematical Modeling and Simulation of Anaerobic Digestion of Solid Waste
No full textAbstractWaste management and energy crisis are the greatest issues that the world is facing today. This problem can be overcome by anaerobic digestion of solid waste, where the waste is converted to biogas: a mixture of mainly carbon dioxide and methane gas. Because of the growing need of anaerobic digestion of solid waste, increased efforts in reducing biogas plant design cost and optimizing process operation is crucial. One way of doing this can be through mathematical modeling of the anaerobic process. The purpose of this paper is to use the Anaerobic Digestion Model no.1 (ADM1), which gives complete information about the physico-chemical reactions in the anaerobic process, to investigate how different parameters in the model affect biogas production. A model was implemented in MATLAB and can be used to find out how the factors such as pH and Volatile Fatty Acid (VFA) affect the daily biogas production
Two Degree of Freedom Controller Design by AGTM\AGMP Matching Method for Time Delay Systems
No full textAbstractThis paper proposes the design of a general Two Degree Of Freedom (2-DOF) controller for time delay systems using a novel method which combines model order reduction, approximate model matching concepts as well as optimization techniques. The desired spectrum is embodied in the form of a transfer function which can be constructed from a set of time domain specifications. The problem of finding the parameters of the 2-DOF controller is formulated as that of obtaining the solution of a set of non-homogeneous linear equations. These set of non-homogeneous linear equations is obtained by using Approximate Generalized Time Moments (AGTM) matching concept, where closed loop response at certain frequency points in s-plane is matched with that of the desired model response. Using genetic algorithm optimum selection of frequency points (expansion points) in s-plane are obtained, which results in an optimum solution of controller parameters. This leads to a high degree of matching of the closed loop response with that of the desired model. The proposed method not only ensures the stability of the closed loop system with a 2-DOF controller but also satisfies the required performance criteria. The developed method does not pose any restriction on either the order of the model or on the structure/order of the controller transfer function. Moreover, this method is computationally simple and easy to implement. Simulation results demonstrate the effectiveness of the proposed method
