Offshore channel clearance is an essential underwater task to protect vessels and divers effectively, but current underwater target classification relies heavily on operator identification. Machine learning provides highly accurate methods for image classification as well as detection. In this paper, a new hybrid quantum-classical classification algorithm is proposed. It uses quantum devices to reduce dimension and denoise data sets, greatly reducing the difficulty of classical computer processing data. Using abundant classical classification algorithms, the classification problem of different scenarios can be processed, improving the classification efficiency. Using two kinds of underwater object data sets as examples, the numerical simulation results show that the quantum algorithm can accurately achieve dimensionality reduction. This hybrid algorithm has polynomial acceleration in dimension reduction than classical methods, even considering the classical readout of quantum data. The results also show that the classification accuracy of the training set improves from 0.772 to 0.821 compared to the original dataset. Furthermore, different classical classifiers can be selected in the case of different objects, so this hybrid algorithm has broad application prospects in different fields.

The advancement of measurement has led to rigorous demands for the accuracy and efficiency of roundness evaluation of minimum zone circle (MZC) for profile with massive points. Existing algorithms struggle to balance efficiency and accuracy in such cases. A fast hybrid roundness evaluation (HCGPSO) algorithm for MZC based on the computational geometry (CG) and particle swarm optimization (PSO) algorithm is proposed, which incorporates a CG-based global best (gBest) selection method into the PSO algorithm and refines the termination criterion. A comparison with the published studies demonstrated that the HCGPSO algorithm were accurate and result are displayed to 10-15 mm. The impact of target accuracy, the harmonic and the number of points contained in profile on the performance of proposed algorithm are analyzed. With sub-nanometer target evaluation precision, HCGPSO enhances efficiency by an average of 64 % for profiles containing the highest harmonics from 30 undulations per revolution (upr) to 500 upr with 1500 points. For profiles with 300 to 4000 points at 150 upr, an average efficiency enhancement of 60 % was observed. For profiles with 4000 points at 500 upr from four workpieces, the calculation time is reduced by 55 % on average compared to the PSO algorithm, with increased accuracy and stability.

Astronomy is a discipline based on observations.The development of modern astronomy,highlighting the importance of astronomical observations in the major discoveries,puts forward higher requirements on astronomical talent.Currently,practice teaching is regarded as one of the most important aspects in undergraduate teaching by all of the departments of astronomy in Chinese colleges and universities.Practice teaching resources show explosive growth in types and quantities with the growing number of inputs for practice teaching,as well as the rapid development of computer,networking and multimedia technology.Tbis article,taking the construction of practice teaching dagital resource library in the department of astronomy in Beijing Normal University for example,explores the systematicness,rationality and sharing of the practice teaching integration.

Astronomy is a discipline based on observations.Trairring of talents in astronomy and public education in astronomy pose various requests to astronmrucal practice teaching.For recent years,Department of Astronomy of Beijing Normal Universily has built multi-level of practice platform for astronomical teaching,providing targeted practice teaching conditions for professional and non-professional,undergraduate and graduate students.New explorations and attempts have been carried out in practice aspects of training of high-quality astronomical talents and teaching of high-quality astronomical public courses.A number of innovative achievements in education and teaching have been obtained which are worth of application and popularization.