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Multiresolution analysis is often used for image representation and processing because it can represent image at the split resolution and scale space. In this paper, a novel medical image segmentation algorithm is proposed that combines contourlet transform and modified active contour model. This method has a new energy formulation by representing the image with the coefficients of a contourlet transform. This results fast and accurate convergence of the contour towards the object boundary. Medical image segmentation using contourlet transforms has shown significant improvement towards the weak and blurred edges of the Magnetic Resonance Image (MRI). Also, the computational complexity is less compared to using traditional level sets and variational level sets for medical image segmentation. The special property of the contourlet transform is that, the directional information is preserved in each sub-band and is captured by computing its energy. This energy is capable of enhancing weak and complex boundaries in details. Performance of medical image segmentation algorithm using contourlet transform is compared with other deformable models in terms of various performance measures.

Mobile Ad Hoc Networks (MANETs) are dynamic and self-configuring networks characterized by node mobility and decentralized operations. Efficient routing protocols play a crucial role in ensuring reliable communication while optimizing resource usage, particularly energy consumption. This paper presents a comparative performance evaluation of three prominent routing algorithms, such as S-DYMO, M-DYMO, and FB-B-DYMO, focusing on their scalability and energy efficiency in MANET environments. This study utilizes simulation-based experiments to assess the performance metrics of S-DYMO, M-DYMO, and FB-B-DYMO. Key parameters evaluated include packet delivery ratio (PDR), end-to-end delay, routing overhead, and energy consumption under varying network sizes and mobility scenarios. Each algorithm's ability to scale with network size and maintain performance under dynamic conditions is analyzed to understand its suitability for real-world MANET deployments. The results indicate that S-DYMO exhibits robust scalability and efficient energy utilization in small to medium-sized networks, leveraging its proactive route discovery approach. Conversely, M-DYMO demonstrates competitive performance in larger networks due to its reactive route maintenance strategy, which balances energy efficiency with scalability challenges. FB-DYMO, integrating feedbackbased mechanisms, shows promising results in mitigating routing overhead and energy consumption but exhibits sensitivity to network dynamics. The findings provide insights into the trade-offs between scalability and energy consumption inherent in S-DYMO, M-DYMO, and FB-B-DYMO routing algorithms, offering guidance for selecting appropriate protocols based on specific MANET deployment scenarios. Future research directions include enhancing protocol adaptability to dynamic network conditions and optimizing energy-efficient routing strategies tailored for evolving MANET environments. [ABSTRACT FROM AUTHOR]

MANETs are a type of wireless ad hoc network characterized by a wireless medium. The MANET's inherent characteristics, like dynamic change in topology and lack of central administration, reduce the possibility of provisioning security. Most of the studies have concentrated more on providing security than the computational cost of energy utilization. Neighbor security is proposed in this paper in addition to the existing de facto ANODR protocol for provisioning security in ANODR. The design and implementation of FB-NTT-S-ANODR to minimize energy consumption, thereby enhancing the network lifetime, are suggested. A soft computing technique for optimizing the performance of FB-NTT-S-ANODR is attempted. From experimental results, the proposed FB-NTT-S-ANODR minimizes the total energy consumption by 93.07%. Hence, the proposed method is more suitable for provisioning security and enhancing the network lifetime. [ABSTRACT FROM AUTHOR]