The emission and mitigation of greenhouse gases transforms the status of urban environments. However, a policy accounting for all the aspects associated with transport is lacking. Problems related to transport include a greater reliance on cars, increased congestion, and environmental impacts. The absence of an efficient public transport system is a notable cause of the prompt escalation of diverse problems, for example, increases in the number of personal automobiles causes congestion on the road, resulting in air pollution, ubiquitous greenhouse effects and noise pollution, which ultimately affect human health. Transit oriented development (TOD) has been suggested as a solution to these problems. This paper reviews the impacts of transit development on urban development, greenhouse impact, the environment, economy, property value, travel behavior, and health etc., highlighting the policy issues which hinder TOD. Implementation of TOD has a strong impact on shaping the urban form, redevelopment, and the upgradation of old areas. Controlling transit phenomena will also help to control the emission and mitigation of greenhouse gases. This study will help in improving the urban environment and climatic condition of regions.

Path planning is one of the key technologies in the research of autonomous surface vessels (ASVs). In this paper, an improved artificial fish swarm algorithm (IAFSA) is proposed. The algorithm is modified from four perspectives: (1) A directional operator is introduced to improve the efficiency. (2) To avoid local optimum, a probability weight factor is proposed to adjust the frequency of executing random behaviour. (3) An adaptive operator has been applied aims at better convergence performance. (4) The waypoint modifying path smoother is used to improve the path quality. A comparative study has been carried out between IAFSA and the other state-of-the-art algorithms, and the results indicate that the proposed algorithm outperforms the others in both efficiency and path quality. Finally, IAFSA is integrated into the GNC system in a model ship. A computer-based sea trial around the Nan Hai area has been conducted, and environmental disturbances including wind, waves, and currents are considered. The results have shown that IAFSA is suitable for practical application.

Seamless integration of both terrestrial and non-terrestrial networks is crucial to providing full-dimensional wireless and ubiquitous coverage, particularly catering to those engaged in marine activities. Compared to terrestrial networks, wireless communications in the marine domain are still not satisfactory for ubiquitous connectivity. Featuring agile maneuverability and strong adaptive capability, autonomous marine vehicles (AMVs) play a pivotal role in enhancing communication coverage by relaying or collecting data. However, path planning for maritime data harvesting is one of the most critical issues to enhance transmission efficiency while ensuring safe sailing for AMVs; yet it has rarely been discussed under this context. This paper provides a comprehensive and holistic overview of path-planning techniques custom-tailored for the purpose of maritime data collection. Specifically, we commence with a general portrayal of fundamental models, including system architectures, problem formulations, objective functions, and associated constraints. Subsequently, we summarize the various algorithms, methodologies, platforms, tools, coding environments, and their practical implementations for addressing these models. Furthermore, we delve into the burgeoning applications of path planning in the realm of maritime data harvesting and illuminate potential avenues for upcoming research endeavors. We believe that future research may focus on developing techniques to adapt more intricate and uncertain scenarios, such as sensor failures, inaccurate state estimations, complete modeling of communication channels, ocean dynamics, and application of heterogeneous systems.

Several approaches have been used in the past to predict fatigue crack growth rates in T-joints of the offshore structures, but there are relatively few cases of applying structural health monitoring during the non-destructive testing of jacket platforms. This paper presents an experimental method based on the sensing of the piezoelectric sensors and finite element analysis method for studying the fatigue cracks in the offshore steel jacket structure. Three types of joints are selected in the current research work: T-type plate, T-type tube-plate, and T-type tube joints. The finite element analysis model established in the current study computes and analyzes the high stress and high strain regions in the T-type joints. The fatigue damage in the T-type joints was successfully detected by utilizing both the finite element analysis and experimental methods. The results showed that fatigue cracks of the three types of joints are prone to appear at the weld toe and spread in the welding direction. The fatigue damage location of T-type plate and T-type tube-plate joints is more concentrated in the upper weld toe area, and the fatigue damage location of the T-type tube joint is closer to the lower weld toe area.

During the service life of the offshore pipelines, different failure mechanisms like external/internal sheath damage, fatigue damage, or corrosion may arise. Therefore, high operating costs need to be consumed to confirm the fitness of the pipeline system. This research deals with an enhanced Risk-Based Inspection (RBI) methodology to certify the integrity management of the pipeline system, a radical new way of RBI practice is introduced for analysing steel pipeline and flexible pipeline. Case studies are executed to designate and give knowledge of how the technique works in exercise with what outcomes can be discovered. The discoveries present features of uncertainties which may not have been measured when implementing the traditional RBI scheme. The scope of this research is to display that with an efficient technique of execution the RBI practice, the failures of pipeline systems can be monitored and control system to ensures the integrity of the pipeline’s system.