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Abstract Covering array generation (CAG) is the key research problem in combinatorial testing and is an NP‐complete problem. With the increasing complexity of software under test and the need for higher interaction covering strength t, the techniques for constructing high‐strength covering arrays are expected. This paper presents a hybrid heuristic memetic algorithm named QSSMA for high‐strength CAG problem. The sub‐optimal solution acceptance rate is introduced to generate multiple test cases after each iteration to improve the efficiency of constructing high‐covering strength test suites. The QSSMA method could successfully build high‐strength test suites for some instances where t up to 15 within one day cutoff time and report five new best test suite size records. Extensive experiments demonstrate that QSSMA is a competitive method compared to state‐of‐the‐art methods.

With the development of science and technology, modern communication and advanced military equipment system increasingly rely on complex communication, electronic equipment and system technology, which require very high demand for broadband communications. Therefore, the propagation characteristic of electromagnetic wave in the marine atmospheric duct environment is researched in this paper. Based on the introduction of the related basic knowledge of radio in atmospheric environment, the reference earth model and atmospheric structure parameters are determined, then the multipath characteristics of the waveguide transmission are analyzed and modeled with the combination of PE theory and related theories, and the loss performance of the low altitude atmospheric duct in horizontal and vertical space is simulated. In addition, the PE method is used to analyze the field distribution of electromagnetic wave propagation in the waveguide, the simulation results show that the PE analysis has a good effect on the high frequency electromagnetic wave over GHz, and the multipath propagation in waveguide has great advantage in long distance communication. The research in this paper gets the constructive and innovative achievements in the establishment of the multipath model, the loss performance and the visual analysis and other aspects. [ABSTRACT FROM AUTHOR]

The reconstruction of the Fokker-Planck equations from time series without prior information is still an open problem. Here, we propose a new method to robustly reconstruct different drift and diffusion terms at different sampling rates. Our method is based on the estimation of the transition probability densities for both of the time series and the stochastic differential equation. We approximate the two terms with the Chebyshev series. Without any prior information, our method can recover the orders and coefficients of the underlying polynomial drift and diffusion terms using the synthetic time series generated by four representative models at different sampling rates. The three important factors affecting the reconstructions are the optimal sample size, the orders, and the coefficients of the Chebyshev series, all of which can be totally determined by a given time series. [ABSTRACT FROM AUTHOR]