The Mathematic Method of Membership Conversion from Degree of Coordinates to Degree of Points
In any multi-indexes uncertainty decisions, if choosing membership function to describe the uncertainty of every space-index value about some status, it must meet membership degree conversion, which must solve the conversion from membership degree of coordinates to membership degree of points. But the present methods affect the credibility of result of decision because of the redundant data. So, by mining knowledge information about points’ classification hidden in membership degree of every coordinates, affirming the relation between points’ classification and membership degree of coordinates; eliminating the redundant data in coordinates’ membership for points’ classification by defining distinguishable weight; constructing the mathematic method of conversion from membership degree of coordinates to membership degree of points without the interference of redundant data, providing method basis for solving key computation in multi-indexes uncertainty decisions.
Multi-Level Fuzzy Evaluation Method for Civil Aviation System Safety
An index system was proposed for safety assessment of civil aviation systems. Fuzzy comprehensive evaluation method was used to calculate the safety degrees corresponding to management and to the human-machine-environment system composed of flight, support and maintenance subsystems. The comprehensive safety degree was obtained based on the above degrees, and divided into 5 grades. The system is not safe enough if the comprehensive safety degree is under grade 4. A further evaluation to the data can reveal the possible hints that cause the data to be evaluated as 'bad' or 'very bad', so that precautions can be taken accordingly.
On the use of the Hardening Soil Small Strain model in geotechnical practice
This article highlights the importance of using advanced constitutive soil models in numerical modelling as daily geotechnical practice. In this context, the Hardening Soil (HS) model is presented as the most advanced soil model implemented in the ZSoil finite element code. The article recalls the basic features of the HS model and it explains their role in numerical simulations. The role of pre-failure non-linear behaviour of soils is also discussed. An application of the HS model is illustrated on typical geotechnical problems such as retaining wall excavation, tunnel excavation and undrained loading followed by consolidation.