19 results for “square wave”

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Research ArticleOpen accessIn the abstractElectromagnetic Interference Mitigation for Inverter fed AC DrivesC. Karthikeyan, K. DuraiswamyProblem statement: In switched mode PWM inverter EMI noise occurs during high (dv/dt) transient period. This EMI noise is mitigated using Active Common mode EMI filter in front of the source. Approach: This study proposes a new active common mode Electromagnetic Interference (EMI) filter for switched mode PWM Inverter applications. The proposed filter is based on current sensing and compensation … …American Journal of Applied Sciences, Vol. 8, Issue 10 · 12 Sep 2011 · 7,309 accessesView PDF Cite

Research ArticleOpen accessIn the abstractDesign and Optimization of a 1.55 µm Waveguide Based on Silicon Planar Photonic CrystalsR. Bchir, A. Bardaoui, M. Machhout et al.Background: Silicon based Planar Photonic Crystals (PPC) are used for the design of a 1.55 µm waveguide. Line defects are then formed in the PPC structures, by removing rows of holes, to obtain a Planar Photonic Crystal Waveguide (PPCW). Objective: First, we varied the thickness of the Silicon slab and the pore radius in order to obtain optimum design parameters … …American Journal of Applied Sciences, Vol. 7, Issue 1 · 31 Jan 2010 · 7,472 accessesView PDF Cite

Research ArticleOpen accessIn the abstractEffects of Low Frequencies on Three Phase Induction Motor Performance Operating in Close Proximity to Rated SpeedQazem Jaber, Qais Naman, Mahdi ShamaseenVariable speed drives (VSD) are adhered to induction motors in most of the present industrial applications. And since the world has become more conscientious to energy saving, inverters established them selves in domestic buildings and industry. Square wave inverters generate dominant harmonics of the 5th, 7th, 11th and 13th order. Inverters based on PWM strategy produce much higher harmonic order … …American Journal of Applied Sciences, Vol. 4, Issue 5 · 31 May 2007 · 7,516 accessesView PDF Cite

Research ArticleOpen accessIn the abstractAn Algebraic Approach to the Harmonic Oscillator Plus an Inverse Square Potential in Three DimensionsShi-Hai Dong, M. Lozada-CassouThe eigenfunctions and eigenvalues of the three-dimensional Schrödinger equation with a harmonic oscillator plus an inverse square interaction are obtained. A realization of the ladder operators for the wave functions is studied. It is found that these operators satisfy the commutation relations of an SU(1,1) group. The closed analytical expressions for the matrix elements of different functions ρ and ρd/dρ … …American Journal of Applied Sciences, Vol. 2, Issue 1 · 31 Jan 2005 · 7,279 accessesView PDF Cite

Research ArticleOpen accessIn the abstractNondestructive Assessment of Egg Freshness using a Synchronous Fluorescence Spectral TechniqueJianhu Wu, Guifeng Li, Yankun Peng et al.Freshness is an important index of egg quality. In this study, a synchronous fluorescence spectral technique was employed to determine the freshness of an intact egg. Synchronous fluorescence spectra of intact eggs were acquired using a fluorescence spectrometer supported by a laboratory fluorescence acquisition device and egg freshness (Haugh Unit) was obtained using destructive methods. Eggs feature fluorescence signals were … …American Journal of Biochemistry and Biotechnology, Vol. 15, Issue 4 · 19 Dec 2019 · 8,132 accessesView PDF Cite

Research ArticleOpen accessIn the abstractA Non-Iterative Method for Factorization of Positive Matrix in Discrete Wavelet Transform Based Image CompressionNallathai Perumalsamy, Nithyanandam NatarajanA non-iterative method of factorizing a 4×4 positive matrix, with the application to image compression is explained using an example. The procedure is applied to all the 4096 number of 4×4 pixel sub-blocks of a 256×256 image for compression. The proposed compression technique can be applied to the Discrete Wavelet Transform (DWT) coefficients of the test image. The 16 Pixel … …American Journal of Applied Sciences, Vol. 10, Issue 7 · 17 Jun 2013 · 6,542 accessesView PDF Cite

Research ArticleOpen accessIn the abstractA Novel Thermooptic Polymer Switch Based on Directional Coupler StructureAbu Sahmah Mohd Supa’at, Mohd. Haniff Ibrahim, Abu Bakar Mohammad et al.A novel thermooptic (TO) polymer switch based on directional coupler structure is proposed for the first time. The key element of the proposed switch is a buried square core polymer waveguides which has been designed for optimum mode matching and coupling with the single mode optical fiber configuration and have large effective index difference by the thermooptic effects. At a … …American Journal of Applied Sciences, Vol. 5, Issue 11 · 30 Nov 2008 · 6,374 accessesView PDF Cite

Research ArticleOpen accessIn the abstractOptimization of Reservoir Operation Using Combined Genetic Algorithm and Wavelet Transform MethodL. Ebrahimi, G.A. Barani, H. EbrahimiDams construction are high cost projects, and therefore, optimal using of reservoir storages behind dams is an important task in water resources management. In last decades, various optimization techniques have been used for reservoir operation. Among the new methods, Genetic Algorithm (GA) and wavelet transform (WT) have been widely used in recent years. In this study, GA as well as … …American Journal of Agricultural and Biological Sciences, Vol. 2, Issue 3 · 30 Sep 2007 · 7,512 accessesView PDF Cite

Research ArticleOpen accessAll words, across the recordPerformance Analysis of Multi Spectral Band Image Compression using Discrete Wavelet TransformR. Kousalyadevi, S. S. RamakrishnanProblem statement: Efficient and effective utilization of transmission bandwidth and storage capacity have been a core area of research for remote sensing images. Hence image compression is required for multi-band satellite imagery. In addition, image quality is also an important factor after compression and reconstruction. Approach: In this investigation, the discrete wavelet transform is used to compress the Landsat5 agriculture … …Journal of Computer Science, Vol. 8, Issue 5 · 6 Mar 2012 · 7,041 accessesView PDF Cite