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Semi-filterless optical networks (semi-FONs), a novel passive wide area network (WAN) solution, have attracted considerable attention. This paper investigates the dynamic routing, modulation and spectrum assignment (RMSA) problem in semi-FONs, where requests may propagate on unnecessary links due to the broadcast characteristics of semi-FONs, resulting in wastage of spectrum resources. Moreover, the dynamically setup and torn down of requests can lead to significant spectrum fragments. To address these issues, this paper studies semi-FONs based on two metrics: resource consumption M and fragmentation degree N. Resource consumption M refers to reducing spectrum wastage caused by broadcasting and establishing requests using minimal resources, while fragmentation degree N refers to the situation where the remaining available resources after establishing a request are more concentrated. Based on these metrics, we propose the Minimum Resource Consumption and Fragmentation Degree (Min-RCF) algorithm. We conduct simulation experiments on the German-Net and China's Henan-Net network topologies, and the results demonstrate that the proposed Min-RCF algorithm achieves lower blocking probability and spectrum waste rate than the compared algorithms. • In the routing phase, resource consumption and spectrum wastage are reduced. • In the spectrum assignment phase, the spectrum fragmentation is reduced. • Reduced blocking probability and spectrum waste rate in the semi-filterless network. [ABSTRACT FROM AUTHOR]

To accurately evaluate the development level of ecological civilization in coastal cities, this paper proposes an evaluation algorithm of coastal city ecological civilization development based on Improved BP neural network, constructs the evaluation index system, and establishes the BP neural network-based evaluation model. By collecting the relevant data of 30 cities in China Line standardization, as the input learning matrix, entropy and coefficient of variation are used to evaluate the development level of ecological civilization. Through 5000 training times, the error accuracy is close to 10–7, and the cities with low ecological civilization level and less cultivated land resources per capita are found out. Based on the improved BP neural network method, according to the development level of coastal cities, the ecological culture of coastal cities is put forward as a whole. The countermeasures and suggestions of construction are given. • In this study, the ecological civilization development level of the coastal cities in Jiangsu was evaluated. • The evaluation results showed the overall development level of ecological civilization. • In the assessment, the comprehensive level of the secondary indexes is better than that of Donghai and Guanyun. • Jiangsu coastal cities have higher ecological civilization development levels, and Donghai and Guanyun is relatively low. [ABSTRACT FROM AUTHOR]