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Go to Editorial ManagerThe efficient and fast-tracking of the global maximum power point (GMPP) under partial shading conditions (PSCs) is one of the most significant goals of the maximum power point tracking (MPPT) algorithms. This paper introduces an algorithm to identify the accurate range locations of the GMPP. A skipping MPPT algorithm is proposed to minimize the time consumed in tracking the GMPP. The proposed algorithm uses a skipping voltage method to minimize scanning the voltage range on the Power-Voltage (P-V) curve by neglecting the zones without GMPP. During GMPP tracking under PSCs, the automatic initial voltage generator algorithm ensures no overlap between two adjacent zones on the P-V curve. The proposed skipping algorithm guarantees that the GMPP is tracked accurately under all potential atmospheric circumstances with a shorter tracking time and the ability to find the GMPP quickly, minimizing the power loss. The improved performance of the proposed algorithm has been validated by simulation and experimental results on a PV string. From the results, the proposed MPPT algorithm has demonstrated its superiority in tracking the GMPP under PSCs in terms of accuracy and tracking speed compared to other MPPT algorithms. The proposed algorithm tracks the GMPP faster, with a time difference of Δt = 3.28 sec and Δt = 27 msec from the experimental and simulation results under PSCs. The proposed algorithm also successfully tracks the GMPP in the final zone, while the 0.8VOCM MPPT algorithm fails, which causes a high-power loss of 196 watts compared to the proposed skipping algorithm.
In this paper, a new compact coplanar antenna used for Radio frequency identification (FID) applications is presented. This antenna is operated at the resonant frequency of 2.45 GHz. The proposed antenna is designed on an epoxy substrate material type (FR-4) with small size of (40 × 28) mm2 in which the dielectric thickness (h) of 1.6 mm, relative permittivity (er) of 4.3 and tangent loss of 0.025. In this design the return loss is less than −10 dB in the frequency interval (2.12 − 2.84) GHz and the minimum value of return loss is -32 dB at resonant frequency. The maximum gain of the proposed antenna is 1.22 dB and the maximum directivity obtained is 2.27 dB. The patch and the ground plane of the proposed antenna are in the same surface. The proposed antenna has a wide bandwidth and omnidirectional radiation pattern with small size. The overall size of the compact antenna is (40 × 28 × 1.635) mm3. The Computer Simulation Technology (CST) microwave studio software is used for simulation and gets layout design.
In order to reduce the impact of watermark embedding on the perceptual fidelity of the marked signal, watermarking systems process the generated watermark to match it to the local properties of the underlying host signal prior to embedding. However, this adaptation process could distort the watermark, affecting its robustness and information content. In this paper, a new watermark coding technique is proposed, that enables the application of some mark- nondistorting host-adaptation processing, where the intensity of the watermark could be redistributed according to the local properties of the underlying host without changing the way of interpreting the watermark to be embedded. This completely eliminates the need to equalize adaptation distortions prior to decoding, and hence, to pass any side information about the adaptation processing to the decoder, too.