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Go to Editorial ManagerIn this paper, image deblwring and denoising are presented. The used images were blurred either with Gaussian or motion blur and corrupted either by Gaussian noise or by salt & pepper noise. In our algorithm, a discrete wavelet transform is used to dJvide the image into two parts. This partition will help in increasing the manipulation speed of images that are of the big sizes. Therefore, the first part represents the approximation coefficients, that a blur is reduced b,y using the modified fixed-phase iterative algorithm. While the second part represents the detail coefficients, that a noise is removed by using the BayesShrink wavelet thresholding method.
The excitation and governing control of generator play an important role in improving the dynamic and transient stability of power system. Typically the excitation control and governing control are designed independently. This paper, presented Neuro-Fu;,.zy methods for the excitation and governing control . Neuro-Fuz.zy system is applied to generate two compensating signals to modify the controls dwing system disturbances. A single machine to infinite bus (SMIB) system is applied in simulation. The MATLAB SIMULIK and S-function technique is used to simulate the system and controllers
Performance a double slope of the solar still Integrated With or without parabolic trough collector is investigated experimentally. To improve the output of a double slope solar still, a number of initiatives have been undertaken, using wax as a phase change material (PCM) with a parabolic trough collector. A parabolic trough collector (PTC) transfers incident solar energy to the solar still through a water tube connected to a heat exchanger embedded in used microcrystalline wax. Experiments were carried out after orienting the basin to the south and holding the water depth in the basin at 20 mm. According to the results obtained, the solar stills with parabolic trough collector have higher temperatures and productivity than solar stills without parabolic trough collector, as well as the ability to store latent heat energy in solar still, allowing fresh water to condense even after sunset. In addition, the parabolic trough collector with phase change material in the double slope solar improves productivity by 37.3 % and 42 %, respectively.
In this paper, the design of linear phase FIR digital filter using Frequency Sampling method is presented. Such design is achieved with a reduction in the maximum stop-band ripples utilizing optimal transition-band sample value throughout the use of Golden Section search method for single transition samples, and with aid of Steepest Descent method for double transition samples. The realization requirements of such filters are reduced by the use of a new analytic design. The reduction can be increased to 50% of the whole filter structure. Therefore, the designed FIR filter offers global properties, minimum stop-band, minimum pass-band, average deviation, and reduced structure complexity.
In This paper, an experimental study was carried out on a dual channel with perforating “V” corrugated absorber plate of solar air collector which the air flows both in upper channel and lower channel of the absorber plate for increasing heat transfer coefficient and improving thermal performance. The results of experimental procedures for dual channel with perforating “V” corrugated absorber plate of solar collector were compared with the flat plate dual channel of solar collector. Experimental calculations had been performed under Baghdad (33.34° North latitude, 44.4° East longitude) climatic conditions at different values of mass flow rates 0.021 kg/s, 0.027 kg/s and 0.32 kg/s. The results showed that the dual channel with perforating “V” corrugated absorber plate of solar collector is found to perform more efficiently than the flat plate dual channel of solar collector with increased 39% in thermal efficiency. Then, it showed that the efficiency increases with increasing mass flow rates. Also, it showed that the heat removal factor of the dual channel with perforating “V” corrugated absorber plate of solar collector is 36% more than the flat plate dual channel of solar collector. At the last part of the study, the exergy relations were derived for both collectors. The results of this part showed that the flat plate dual channel of solar collector is having largest irreversibility (exergy loss) and the dual channel with perforating “V” corrugated absorber plate of solar collector is having a greatest exergetic efficiency.
A novel iterative method for the restoration of gray-scale blurred images is presented. The method is an enhanced modification of the Fixed-Phase Iterative Algorithm (FPIA). A blurred image is enhanced by Laplace operator during the FPIA method on each iteration. This modification is originally supported theoretically by a derivation of some iterative deblurring methods that are based on the enhanced version of the blurred image instead of the blurred image itself only. The modified fixed phase iterative algorithm (MFPIA) method is examined to restore some Gaussian-and motion-blurred gray-scale images. The restored Images via this proposed method are compared with the original FPIA method. From the comparison, it is apparent that the MFPIA method is better from human visual measurements point of view with less number of iterations. In addition to that benefit the restoration by the FPIA method results in images of bad quality even with high number of iterations.
Single roll melt spinning is a non-conventional forming process used to produce rapidly solidified thin ribbons as a near net shaper by direct casting from liquid state. In this paper, single roll made from brass with a diameter of 150 mm was used to produce rapidly solidified Al-Mg alloys ribbons. The ribbons are produced with thickness in the range of 20 to 330 µm. The results exhibited unique advantages in refining the microstructure, and modifying the mechanical properties of these ribbons. The hardness was improved to about twice the original hardness of alloy. Moreover, corrosion resistance of alloy was improved and their rate was redcued from 10.02 to 1.643 mpy for alloy type 5052 and from 6.91 to 1.943 mpy for 5083.
In this paper induction motor and its direct torque control are simulated and a speed estimator scheme based on wavenet (WN) theory has been developed and compared with the actual speed. The wavenet speed estimator inputs are a single line current and the state of the torque comparator output which are trained to follow the relationship between the motor current and the rotor speed. To ensure the validity of this scheme, the estimated speed is compared with a speed estimated from a conventional model reference adaptive system (MRAS). The operation of direct torque control (DTC) drive with the actual speed and the estimated wavenet speed as a feedback signal are simulated and compared. The results show that the wavenet method is effective for rotor speed estimation.
The effect of fouling due to scale formation of pre-heater tubes on the thermal performance of Reticulating multi stage flash Distillation plant performance ratio and the increase of the ratio of Makeup water to the product Quantity for a 5MGPD recirculating System has been prediction The results appeared That eth Effect of scale formation is more Effected as the Maximum brine temperature decrease.
A simple analytic design procedure for Lattice Wave Digital Filters (LWDFs) is presented with approximate linear phase. The design is started by replacing one of the two all-pass filter branches in LWDF with a pure delay and terminated by some analytic design formulas. Using Matlab 7.4, several design examples of the odd order type utilizing such procedure are given for verifications.