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.
Ozonation of polycyclic aromatic hydrocarbons in oil/water-emulsions: mass transfer and reaction kinetics.
The ozonation of highly condensed polycyclic aromatic hydrocarbons (PAH) was studied in oil/water-emulsions, which are comparable to poorly water-soluble PAH in industrial wastewaters and at contaminated sites. As there was a lack of knowledge about the ozonation in oil/water-emulsions, first the ozone mass transfer was studied and optimized from the gas to the water phase and from the water to the oil phase. The ratio of mass transfer and oxidation reaction was determined by the Hatta-number and revealed a slow, quasi homogeneous reaction of ozone with PAH inside the oil droplets. Because the ozone gas concentration had no influence under the optimized conditions, the selective PAH-ozonation could be described microkinetically by a direct ozone reaction of pseudo-first order regarding PAH-concentrations. The determined PAH mean reaction rate constants of 1.02 min(-1) in oil/water-emulsions are in the upper range as found for PAH dissolved in water. These results give a new insight into the ozonation in the three-phase systems and into the treatment of highly condensed, hardly biodegradable PAH.