Fuzzy Comprehensive Evaluation of Air Quality in Shijiazhuang City Based on Grey Correlation

[Objectives]This study was conducted to evaluate the air quality of Shijiazhuang City,in order to facilitate the government to correctly formulate measures to prevent and control air pollution and protect Shijiazhuang's ambient air quality. [Methods] With the air quality data of Shijiazhuang City from February to March in 2019 as the research object,the gray correlation analysis method was used to determine weight A of each pollutant factor first,and then a single factor evaluation matrix R was constructed. The weight A and the single factor evaluation matrix R were synthesized using the M( ·,+) fuzzy composite operator,obtaining a fuzzy matrix B between the factor set and the evaluation level. [Results] The eigenvalue of air quality was calculated according to matrix B: H = 2. 259 5.[Conclusions]The air quality in Shijiazhuang City from February to March was between grade 2 and grade 3,closer to grade 2,indicating that the air quality was good.

Comprehensive Evaluation Method for Traffic Flow Data Quality Based on Grey Correlation Analysis and Particle Swarm Optimization

Nowadays,data are more and more used for intelligent modeling and prediction,and the comprehensive evaluation of data quality is getting more and more attention as a necessary means to measure whether the data are usable or not.However,the comprehensive evaluation method of data quality mostly contains the subjective factors of the evaluator,so how to comprehensively and objectively evaluate the data has become a bottleneck that needs to be solved in the research of comprehensive evaluation method.In order to evaluate the data more comprehensively,objectively and differentially,a novel comprehensive evaluation method based on particle swarm optimization(PSO)and grey correlation analysis(GCA)is presented in this paper.At first,an improved GCA evaluation model based on the technique for order preference by similarity to an ideal solution(TOPSIS)is proposed.Then,an objective function model of maximum difference of the comprehensive evaluation values is built,and the PSO algorithm is used to optimize the weights of the improved GCA evaluation model based on the objective function model.Finally,the performance of the proposed method is investigated through parameter analysis.A performance comparison of traffic flow data is carried out,and the simulation results show that the maximum average difference between the evaluation results and its mean value(MDR)of the proposed comprehensive evaluation method is 33.24%higher than that of TOPSIS-GCA,and 6.86%higher than that of GCA.The proposed method has better differentiation than other methods,which means that it objectively and comprehensively evaluates the data from both the relevance and differentiation of the data,and the results more effectively reflect the differences in data quality,which will provide more effective data support for intelligent modeling,prediction and other applications.

Study on evaluation of cities' ability reducing earthquake disasters

Cities ability reducing earthquake disasters is a complex system involving numerous factors, moreover the re-search on evaluating cities ability reducing earthquake disasters relates to multi-subject, such as earthquake sci-ence, social science, economical science and so on. In this paper, firstly, the conception of cities ability reducing earthquake disasters is presented, and the ability could be evaluated with three basic elements the possible seis-mic casualty and economic loss during the future earthquakes that are likely to occur in the city and its surround-ings and time required for recovery after earthquake; based upon these three basic elements, a framework, which consists of six main components, for evaluating citys ability reducing earthquake disasters is proposed; then the statistical relations between the index system and the ratio of seismic casualty, the ratio of economic loss and re-covery time are gained utilizing the cities prediction results of earthquake disasters which were made during the ninth five-year plan; at last, the method defining the comprehensive index of cities ability reducing earthquake disasters is presented. Thus the relatively comprehensive theory frame is set up. The frame can evaluate cities ability reducing earthquake disasters absolutely and quantitatively and consequently instruct the decision-making on reducing cities earthquake disasters loss.