New Method For Suppression Research Articles

Image Denoising Analysis Using Adaptive Subband Thresholding and Wavelet Packet

In image processing, removal of noise without blurring the image edges is a difficult problem. Aiming at orthogonal wavelet transform and traditional thresholds shortage, a new adaptive threshold image de-noising method which is based on wavelet packet transform, decomposition level and sub band coefficients is proposed. The image is decomposed into the low frequency part and high frequency part by using wavelet packet transform and the wavelet packet tree coefficients are processed with soft threshold by using the level dependent adaptive threshold. The proposed method describes a new method for suppression of noise in image by fusing the wavelet Packet (WP) transform (WPT) along with optimal wavelet basis (OWB) (WPTOWB) for image decomposition. Shannon entropy is implemented to produce the optimal wavelet basis function. Then, for each wavelet subband, an adaptive threshold value to which a multiplying factor (α) is included making the threshold value dependent on decomposition level and subband’s statistical parameters are estimated. From the experiment result, we see that compared with traditional methods, this method can not only effectively eliminate noise, but can also well keep original images information and the quality after image de-noising.

Suppression of the coffee-ring effect in a hectorite aqueous dispersion

The drying patterns of droplets of hectorite aqueous dispersions were studied. The hectorite volume fractions and salt concentrations of the dispersions ranged from 0.001 to 0.01 and from 0.001M to 0.1M, respectively. It was observed that the drying pattern was ring shaped in the absence of salt and bump shaped in the presence of salt. It is highly plausible that, in the presence of a salt, a three-dimensional network structure of hectorites (an attractive gel) is formed and the hectorites are arrested by an electrostatic attractive force among them, which leads to compression of the network structure in the drying process, resulting in the bump-shaped deposit. It was revealed that the dispersion state, “sol” or “gel,” of the hectorite mineral in the water dominates the drying pattern of the hectorite dispersion and offers a new method for suppression of the coffee-ring effect.

Improved bridge type inrush current limiter for primary grounded transformers

This paper presents a new method for suppression of the transformer inrush current of primary grounded transformers. A newly designed diode-bridge in a neutral winding transformer controls the inrush current using simple power circuit topology without any control or gate drive circuits or measurement tools. Since the number of diodes in this design has been minimized, the ripple and electrical losses decrease while operational reliability increases. The proposed method has been evaluated in laboratory tests and computer simulations. The good agreement of experimental and simulation results verifies the effectiveness of this method.

A Novel Image Denoising using Matched Partial Biorthogonal Wavelets and Adaptive Thresholding

denoising of a natural image corrupted by Gaussian noise is a problem in signal or image processing Even though much work has been done in the field of wavelet thresholding, most of it was focused on statistical modeling of wavelet coefficients and the optimal choice of thresholds. This paper describes a new method for suppression of noise in image by fusing the wavelet Denoising technique with optimized thresholding function, improving the denoised results significantly by using partial biorthogonal wavelets. In today's scenario denoising techniques use the classical orthonormal wavelets for decomposition of an image corrupted with additive white Gaussian noise, upon which various thresholding strategies are built. We present a method to design partial biorthogonal wavelet bases and report on their potential for denoising. This paper describes a new method for suppression of noise in image by fusing the wavelet Denoising technique with optimized thresholding function, improving the denoised results significantly. Simulated noise images are used to evaluate the denoising performance of proposed algorithm along with another wavelet-based denoising algorithm. Experimental result shows that the proposed denoising method outperforms standard wavelet denoising techniques in terms of the PSNR and the preservation of edge information. The use of available biorthogonal wavelets in image denoising is less common because of their poor performance. But when we combine the approach of fusion with partial biorthogonal wavelets then the performance is increases in comparison of traditional methodology. This point to the importance of matching when using wavelet-based denoising.

Open-loop control of a stepping motor using oscillation-suppressive exciting sequence tuned by genetic algorithm

A new method for suppression of rotor oscillation in open-loop drive of a stepping motor is proposed. In this method, the torque equilibrium position of the motor is manipulated so as to guarantee insensitiveness to the variation of rotor inertia; the motion of the equilibrium position is made to be nonoscillatory, and the frequency of the motion is bound within the region limited by the maximum frequency determined by considering the performance on the condition with the largest inertial load. The exciting sequence used for a single-step drive is tuned by using the technique of genetic algorithm. It is shown by the experimental results that rotor oscillation can be well suppressed on the load conditions with different inertial loads.

New Method for Constraints Violation Suppression

The problem of constraints violation associated with numerical integration of dynamical equations of motion subject to constraints is dealt with. A new method for the suppression of constraints violation is presented. The method involves the dee nition of old constraints and of new constraints, the removal of the old constraints and the imposition of the new constraints, and the evaluation, after each integration step, of changes in the integration variables resulting from the removal ‐imposition process. The method is shown to be superior to the classical Baumgarte’ s method for constraints violation suppression in three aspects. First, the constraint violation measure number, a quantity dee ned herein, is smaller. Second, the constraint violation measure number stabilizes after the e rst integration step and does not degrade with time. Finally, the new method makes the process of trial and error, required by Baumgarte’ s method for the determination of integration constants, unnecessary. The method is discussed in connection with holonomic and simple nonholonomic constraints.

Optical fibers with depressed claddings for suppression of coupling into cladding modes in fiber Bragg gratings

A new method for suppression of coupling from guided optical modes into cladding modes in an optical fiber Bragg grating using a fiber with a strongly depressed cladding is proposed. Strong suppression of the coupling has been demonstrated both theoretically and experimentally.

Geometric methods for determining system poles from transient response

The problem treated is that of identifying the poles of a finite order system by observing its transient decay after cessation of input, for a limited time, using (possibly) multiple observation points and experimental repetition. Various approaches are studied, having the common characteristic that a homogeneous matrix equation must be solved. Several techniques that have been given scant attention in the literature are consolidated by a geometric treatment, together with new results including an analytical treatment of the consequences of assuming an excessively high system order, derivation of a statistically unbiased estimate for an intermediate parameter in the solution, new theorems on error effects, a recipe for effective use of the singular value decomposition, and a new method for suppression of extraneous poles.

A New Method for Suppression of Hard Bubbles in LPE Garnet Films

A New Method for Suppression of Hard Bubbles in LPE Garnet Films