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Element failure in antenna arrays leads to severe degradation of the radiation pattern. It is significantly more complex in circular antenna arrays (CAA) considering its geometry and elements spatial distribution along the circumference of the circle. Several design parameters like the coefficient of current amplitude excitation, phase, and arc length are determined appropriately to obtain the desired parameters involved in the pattern restoration process. It is possible to rely on alternate desired parameters to restore the patterns without disturbing the actual design parameters involved in the optimization process. In this paper, such an attempt to optimize CAA using non-uniform amplitude distribution is considered. After enforcing multiple-element failure, the resultant defective pattern is restored by determining the non-uniform spatial distribution of four consecutive elements preserving the corresponding non-uniform amplitude distribution. Hence, it is justifying mentioning that the position-only technique is used to restore the pattern in terms of optimized SLL and BW. The spatial distribution of optimized CAA is determined using the latest modified Social Group Optimization Algorithm (MSGOA) and compared the results with the well-known Flower Pollination Algorithm (FPA). The MATLAB® is used to carry out the simulations, and results are analyzed.

In the world, glaucoma is the one of the main causes for loosing vision. Optical Coherence Tomography or fundus camera is utilized to capture the optic disc and optic cup images. For the detection of glaucoma and afterwards monitoring the patients, investigation of the head of optic nerve or cup-to-disc ratio (CDR) is an important factor. For computing the CDR value, segmentation of optic disc and optic cup are utilized for the isolation of the relevant parts of the fundus image. Even though ophthalmologists are computing the CDR value physically, however, it limits the identification of glaucoma at the early stage. The accurate value of CDR is hard to find out if the optic cup and optic disc are not well defined properly. Thus, this paper has suggested a combined model of Guided filter and Discrete Wave Transform (DWT) for the enhancement and OD segmentation. Hysteresis thresholding is utilized for the optic cup segmentation. A set of 50 images of 25 patients are obtained from Visakha Eye Hospital, Visakhapatnam, India, is used to verify the performance of the suggested model. The recommended approach is also verified on the glaucoma subset of High-Resolution Fundus (HRF) database. The experimental results of both the databases demonstrate that the CDR value is computed accurately with low computational time.