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Theoretical studies on evolutionary algorithms have developed vigorously in recent years. Many such algorithms have theoretical guarantees in both running time and approximation ratio. Some approximation mechanism seems to be inherently embedded in many evolutionary algorithms. In this paper, we identify such a relation by proposing a unified analysis framework for a global simple multiobjective evolutionary algorithm (GSEMO) and apply it on a minimum weight general cover problem, which is general enough to subsume many important problems including the minimum submodular cover problem in which the submodular function is real-valued, and the minimum connected dominating set problem for which the potential function is nonsubmodular. We show that GSEMO yields theoretically guaranteed approximation ratios matching those achievable by a greedy algorithm in expected polynomial time when the potential function g is polynomial in the input size and the minimum gap between different g-values is a constant. History: Accepted by Erwin Pesch, Area Editor for Heuristic Search & Approximation Algorithms. Funding: This work was supported by National Natural Science Foundation of China [11771013, U20A2068]; Zhejiang Provincial Natural Science Foundation of China [LD19A010001]. [ABSTRACT FROM AUTHOR]

Ultra-deep carbonate reservoirs buried over 7000 m are distributed around strike-slip faults, which control hydrocarbon accumulation and enrichment in the Tarim Basin, China. This study proposes a fracture development index (FDI) method for analyzing the width of the strike-slip fault zone based on 3D seismic data. Based on the FDI method and geological and geophysical data, we analyze the structural characteristics of the SB5 strike-slip fault and the scaling of fault zone width and throw. In map view, at depth the strike-slip fault is characterized by single fault segments, extensional overlaps, and contractional overlaps, at intermediate depths by left-stepping en echelon normal faults, and in shallow layers by right-stepping en echelon normal faults. In cross section, we find composite flower structures and positive flower structures and medium-shallow layer negative flower structures or deep layer negative flower structures and medium-shallow layer negative flower structures. The formation time of deep, middle, and shallow layer faults is the middle Caledonian, Late Caledonian, and Late Hercynian. The heterogeneity of the strike-slip fault zone varies from strong to weak from contractional overlaps, to extensional overlaps, and single fault segments. Strike-slip fault-related fractures are dominated by three sets intersecting with strike-slip faults at small angles. Where throw is less than 100 m, the fault zone width and throw have a good power law relationship. Where the throw is over 100 m, the width tends to diminish with throw. • Geometric and kinematic characterizations of strike-slip fault in ultra-deep carbonates (more than 7000 m). • A method for analyzing the widths of strike-slip fault zones based on 3D seismic data. • Timing of fault in different structural layers. • Heterogeneity and scaling of strike-slip fault zone width and throw. [ABSTRACT FROM AUTHOR]

Is the proliferation of information and communication technologies (ICTs) - especially various social media platforms (e.g. Weibo by SINA and WeChat by Tencent) - causing power shifts within environmental politics in China? This article addresses this question by examining recent theoretical debates on the Internet's democratic potential and situating these arguments in the context of China's online environmental activism. Instead of focusing on the often de-contextualized dichotomy of "control versus resistance," the primary concern of this article is the broader technical and social possesses underpinning China's leapfrog into the digital era. Drawing upon the theories of "technical code" and "infrapolitics," the article argues that the Internet, as a relatively new technology, has not been technically and socially stabilized and thus the future of China's online environmental activism hinges upon the complex interactions among three interconnected factors within the cyberspace: the Chinese society's political economy context, the Internet's evolving technological configurations, and the political and cultural struggles of various social actors. [ABSTRACT FROM AUTHOR]

Identification of key nodes and vital edges are of great importance in aviation network. On the basis of the minimum connected dominating set (MCDS), a backbone network identification method in aviation network was proposed. Key nodes and vital edges are combined as core backbone subnet. The binary particle swarm optimization (BPSO) algorithm is adopted to solve the MCDS problem. Immune mechanism was introduced to guide the search direction of particle nodes to improve the convergence speed of the algorithm. The experiments on artificial network, China airport aviation network and East China airline network show that method is more comprehensive and accurate than other method based on single metric (e.g. degree and closeness centrality methods). And identification results are in good agreement with the actual situation and has high application value in aviation network. • The identification method of key nodes and edges in aviation network based on minimum connected dominating set is proposed. • A new binary particle swarm optimization algorithm based on immune optimization is proposed to solve the minimum connected dominating set in different complex networks. [ABSTRACT FROM AUTHOR]