At present, the research of data storage and management in cloud computing mainly focuses on dealing with data expression and search. This study gives a comprehensive survey of numerous models and approaches of data-intensive applications in cloud computing in both academic and industrial communities. We review various approaches and their ideas of design. And then, we attempt to summarize and appraise the open issues.

In this paper, the instability in spinning process of ultra-thin-wall tube is analyzed, and the influence law of different parameters of roller and main process parameters in spinning forming process. Firstly, the forward spinning finite element model of ultra-thin wall tube is established and its reliability is verified. It is concluded that the instability of ultra-thinwall aluminum alloy tube during spinning is caused by its poor rigidity and material flow disorder. The effects of different parameters of roller (roller diameters, roller forming angles and roller corner radii) and the main process parameters (feed rates, friction coefficients and thinning rates) on the equivalent plastic strain and diameter expansion amount in spinning forming process were investigated. The results show that the influence of each parameter on the stability of ultra-thin-wall is quite different. The influence of roller corner radius is stronger than roller diameter and much stronger than roller forming angle. The influence that feed rate does the expansion amount to exist a minimum value. The friction coefficient and thinning rate have positive correlation with expansion amount. The optimum combination of process parameters was further determined, and the accuracy of the results was verified by experiments, which provided reference and guidance for actual production.

Applying random field theory involves two important issues: the statistical homogeneity (or stationarity) and determination of random field parameters and correlation function. However, the profiles of soil properties are typically assumed to be statistically homogeneous or stationary without rigorous statistical verification. It is also a challenging task to simultaneously determine random field parameters and the correlation function due to a limited amount of direct test data and various uncertainties (e.g., transformation uncertainties) arising during site investigation. This paper presents Bayesian approaches for probabilistic characterization of undrained shear strength using cone penetration test (CPT) data and prior information. Homogeneous soil units are first identified using CPT data and subsequently assessed for weak stationarity by the modified Bartlett test to reject the null hypothesis of stationarity. Then, Bayesian approaches are developed to determine the random field parameters and simultaneously select the most probable correlation function among a pool of candidate correlation functions within the identified statistically homogeneous layers. The proposed approaches are illustrated using CPT data at a clay site in Shanghai, China. It is shown that Bayesian approaches provide a rational tool for proper determination of random field model for probabilistic characterization of undrained shear strength with consideration of transformation uncertainty.

Plastic relief wells along Yangxin Dyke of Yangtze River in China have been seriously clogged in recent years. It is necessary to dredge the wells to restore its disaster prevention and mitigation function. However, traditional piston well-flushing technique is suitable to restore steel and iron wells, and it can cause damage to plastic relief wells. A new light piston well-flushing technique is proposed to overcome the limitation of traditional piston well-flushing technique. The proposed light piston has the advantages of simple structure, convenient use and low cost. By the light piston moving down and up quickly the relief well, the nylon brush can clean the side wall and filters of relief well, and the negative pressure can make the deposited materials in the aquifer and inverted filter sucked out. The proposed well-flushing technique is applied to restore the plastic wells along Yangxin Dyke of Yangtze River in China. Its efficiency is illustrated using field pumping test data. It is shown that the drainage capacity and permeability of clogged relief wells can be greatly improved after using the proposed technique. The light piston well-flushing technique can provide an effective way to restore clogged relief wells along Yangtze River levees.

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