Nowadays, the development of green and smart ships has become a trend in the global shipping industry. Some countries such as Japan and Korea, as well as several European countries, have already made some progress and advantages. In recent years, China has issued a series of policies to encourage and support the development of green and smart ships. Beyond that, the demonstration of green and smart ships has been promoted along with the trend of larger-sized and standardized inland vessels. The Chinese status and plans of green technologies are summarized including air layer drag reduction, efficient propulsion, DC networking, and clean energy. Some smart technologies have also been illustrated, for instance, intelligent driving, intelligent engine rooms, energy efficiency, hulls, cargo control, and information integration. Smart ship technologies need to be fully validated in order to improve industrialization applications. In the shipping industry, the development and application of smart ship technology need international and inter-regional cooperation, so as to achieve much higher energy savings, ensure environmental protection, achieve collaborative intelligence, and ensure safety and reliability. In turn, this will aid economic advances worldwide.

In this study, the finite element method combined with the model test method are used to investigate the ultimate strength of a target ship reactor hull structure under a pure bending load. Based on the distortion similarity theory and nonlinear similarity method, a scale model of the actual ship reactor hull structure is designed and the model collapse test is conducted. The ultimate bending moment obtained by the model test is transformed to the actual ship through the similarity transformation relationship and compared with the nonlinear finite element analysis result of the actual structure. The results are consistent with each other, which indicates that the collapse characteristics of the actual ship reactor hull structure can be better forecasted using the model test results when the test model is designed based on the nonlinear similarity method and distortion similarity theory.

The demand for larger passenger capacity and more entertainment facilities has led to the rapid growth of the cruise tourism market. The superstructure of cruise ships is designed to be plumper, with numerous decks and complex structural forms. To control the weight and the center of gravity, the bending stiffness of the superstructure is always designed to be weaker than that of the main hull, resulting in a stiffness step. Currently, there is no satisfactory method to accurately estimate the influence of the stiffness step between the main hull and superstructure on the structural response of cruise ships. In the present research, an experimental analysis is conducted to investigate the stiffness step between the main hull and superstructure of a typical cruise ship. By comparing the longitudinal stress distribution characteristics with and without the stiffness step with the theoretical results, the influence of the stiffness step on the longitudinal strength is investigated. Furthermore, the maximum stress and the bending efficiency of the superstructure are also discussed. The present research is of reference significance for the structural safety and reliability design of cruise ships.

Complex networks can be considered as abstractions of complex systems existing in the real world. The potential functionality of networks is related to mesoscale structures in networks, among which the representative ones are community structure and core-periphery (CP) structure. Since many real-world networks will inevitably be attacked, it is of great significance to enhance robustness of networks. However, few of the existing studies about robustness have laid emphasis on robustness of CP structure. In this brief, we first propose a new index to measure the ability of CP structure to resist attacks or errors. Several efficient algorithms based on this index are then devised to maximize robustness of CP structure under reasonable constraint. Numerical results show that the robustness of the CP structure of several representative real-world networks is markedly enhanced. The structural changes in the optimized networks under study and their implication are also discussed.