Electrical and Electronics

Rapid growth of mobile communication over the past years has tremendously increased the number of users which reduces the capacity of the system due to the increase in the number of interferers. Space Division Multiple Access (SDMA) is one of the promising technologies for future mobile communication. Smart antennas, usually employed at the base station radiate narrow beams to serve different users by using spatial processing. As long as the users are well separated spatially, the same frequency can be reused even when the users are in the same cell. The paper focuses the use of adaptive antenna arrays in CDMA networks to suppress cochannel interference. The training sequence based adaptive algorithms like the LMS, SMI and RLS algorithms are discussed in detail and the effect of number of antenna elements, inter element spacing, effect of number of interferers and the variation in SNR on the training sequence based adaptive algorithms is studied. The beam formation, null steering, maximum side lobe levels and convergence of these algorithms is studied in detail and compared. Keywords- Smart Antenna, LMS Algorithm, SMI Algorithm, RLS Algorithm, Beam Formation, Null Steering.

In this paper, a medical image watermarking algorithm based on contourlet is proposed. Medical image watermarking is a special subcategory of image watermarking in the sense that images have special requirements. Watermarked medical images should not differ perceptually from their original counterparts because clinical reading of images must not be affected. Watermarking techniques based on wavelet transform are reported in many literatures but robustness and security using contourlet are better when compared to wavelet transform. The main challenge in exploring geometry in images comes from the discrete nature of the data. In this paper, original image is decomposed to two level using contourlet and the watermark is embedded in the resultant sub-bands. Sub-band selection is based on the value of Peak Signal to Noise Ratio (PSNR) that is calculated between watermarked and original image. To extract the watermark, Kernel ICA is used and it has a novel characteristic is that it does not require the transformation process to extract the watermark. Simulation results show that proposed scheme is robust against attacks such as Salt and Pepper noise, Median filtering and rotation. The performance measures like PSNR and Similarity measure are evaluated and compared with Discrete Wavelet Transform (DWT) to prove the robustness of the scheme. Simulations are carried out using Matlab Software.

A novel framework for object – based video inpainting is presented in this paper. To complete an object, first samples a 3-D volume of the video into directional spatio – temporal slices, and then performs patch-based image inpainting to repair the partially damaged object in the 2-D slices. The slices are combined to obtain a sequence of virtual contours of the damaged object. The virtual contours and a posture sequence retrieval technique are then used to retrieve the most similar sequence of object postures in the available non-occluded postures. Key-postures selection and indexing are used to reduce the complexity of posture sequence. A synthetic posture generation scheme that enriches the collection of key-postures so as to reduce the effect of insufficient key-postures.

A centrality measure has been proposed considering the directionality of power flow of future smart grid. Applicability of the proposed method has been evaluated in several standard IEEE test systems. Various comparisons are shown between impacts of removal of critical nodes found from two different models: nondirectional and bidirectional. Larger impact of removing critical nodes found from bidirectional flow model shows the utility of the proposed method. Measures of impacts considered are changes in path length, loss of connectivity and load lost during cascade.

Seeker optimization algorithm (SOA), a novel heuristic population-based search algorithm, is utilized in this paper to solve different economic dispatch (ED) problems of thermal power units. In the SOA, the act of human searching capability and understanding are exploited for the purpose of optimization. In this algorithm, the search direction is based on empirical gradient by evaluating the response to the position changes and the step length is based on uncertainty reasoning by using a simple fuzzy rule. The effectiveness of the algorithm as tested on two large-scale test power systems to solve the ED problems. The results obtained by the SOA are compared to the other different algorithms published in the recent literatures to establish its superiority.

GPS receivers plays a greater role for calculating and determining the precise point positioning and deals with the navigational massages, also one of the main uses of high-end GPS receivers is for scientific research and space science analysis. The handheld GPS receivers were utilized for experimental purposes contrary to the traditional application for recreation and geo-catching activities. The classification of different commercial GPS receivers gave an inside ideas for application and utilization of these receivers in the field of laboratory research. Garmin GPS handheld receivers performed an excellent example in conducting experimental work for GPS propagation data analysis.

Doubly Fed Induction Generators (DFIGs) are currently extensively used in variable speed wind power plants due to their superior advantages that include reduced converter rating, low cost, reduced losses, easy implementation of power factor correction schemes, variable speed operation and four quadrants active and reactive power control capabilities. On the other hand, DFIG sensitivity to grid disturbances, especially for voltage sags represents the main disadvantage of the equipment. In this paper, a coil is proposed to be integrated within the DFIG converters to improve the overall performance of a DFIG-based wind energy conversion system (WECS). The charging and discharging of the coil are controlled by controlling the duty cycle of the switches of the dc-dc chopper. Simulation results reveal the effectiveness of the proposed topology in improving the overall performance of the WECS system under study.

In this paper we are providing an idea of implementing stress analysis algorithms in the basic user interface of the operating system. There are four methods provided from which the user can be analyzed for stress levels by using general usage of his/her cell phone. The mobile device not just performs the task of stress analysis but it also notifies the user if the stress levels go above a critical limit and also notifies the related doctor if the patient ignores the constant notification by the cell phone.

Corona effect has been considered as a source of substantial loss particular to High Voltage AC Transmission lines. The project report presents comprehensive account of development of a Matlab Simulink based model for the Corona Effect which is designed considering Peek’s equation. The model provides analysis of Corona loss impact on Transmission power in response to the variation in the factors on which Corona effect depends upon. The transmission power has been simulated to plot Corona losses based on variation in Temperature, Conductor Radius and Conductor spacing.

The distributed synchronous compensation is a shunt connected FACTS device which supplies reactive power to the load to improve the voltage stability of the load buses. In this system the voltage regulation can be improved by reducing the losses. This work deals with comparison of Push Pull and Voltage Inverter based D-STATCOM for multi bus system. Eight bus system is modeled using the elements of SIMULATION. The models are developed for eight bus system with and without D-STATCOM. The two D- STATCOM systems are compared with respect to total harmonic distortion and reactive power comparison. The D-STATCOM is studied with respect to the voltage stability improvement at the load buses. The results of VSI based D-STATCOM system are compared with those of Push pull inverter based D-STATCOM system.