Underwater wireless sensor networks (UWSNs) have become highly efficient in performing different operations in oceanic environments. Compared to terrestrial wireless sensor networks (TWSNs), MAC and routing protocols in UWSNs are prone to low bandwidth, low throughput, high energy consumption, and high propagation delay. UWSNs are located remotely and do not need to operate with any human involvement. In UWSNs, the majority of sensor batteries have limited energy and very difficult to replace. The uneven use of energy resources is one of the main problems for UWSNs, which reduce the lifetime of the network. Therefore, an energy-efficient MAC and routing techniques are required to address the aforementioned challenges. Several important research projects have been tried to realize this objective by designing energy-efficient MAC and routing protocols to improve efficient data packet routing from Tx anchor node to sensor Rx node. In this article, we concentrate on discussing about different energy-efficient MAC and routing protocols which are presently accessible for UWSNs, categorize both MAC and routing protocols with a new taxonomy, as well as provide a comparative discussion. Finally, we conclude by presenting various current problems and research difficulties for future research.

Background: Medical Resonance Imaging (MRI) images degradation is still a challenging task. The noise is a compulsory destructive factor that gets added in MRI images due to several environmental and mechanical reasons. In this paper, an effort is made and a Genetic Programming (GP) based hybrid noise removal approach is proposed which reduces the effect of Rician noise of MRI images. Methods: The proposed approach preserves the structural and edges details of the regions of the images. The proposed GP approach uses Feature Extraction phase, GP based Optimal Expression module and Optimal Extraction based Estimation module to remove Rician noise. To validate the proposed approach, the proposed method is tested on different medical samples and the obtained results are compared with results retrieved through the existing comparative approaches. Conclusion: The experimental results show that the proposed approach performs efficiently and can be implemented in real world applications.

The journal retracts the article, entitled “A Comprehensive Survey of Energy-Efficient MAC and Routing Protocols for Underwater Wireless Sensor Networks”

Background: The area of image processing extends from basic image compression model to high end applications such as astronomical data processing and medical image processing. Images have vast features and coding them into lower bit rates results in the loss of information. Methods: This study proposes a novel hybrid approach to compress the image no loss of information and to maintain reduced processing overhead. Discussion: To validate the proposed approach, the suggested method is tested on different medical samples and the obtained results are compared with results retrived through the conventional JPEG based coding approach. Conclusion: The experimental results show that the proposed approach performs efficiently and can be implemented in realworld applications.