(11) Step 5. Calculate distance between dangerous goods transport enterprise and its ideal points. Suppose the distance between each enterprise under assessment and its positive ideal point and negative ideal point is d j + and Apocynin Acetovanillone d j −, respectively, described as follows: dj+=∑i=1mbij∗−pi+2, j=1,2,…,n,dj−=∑i=1mbij∗−pi−2, j=1,2,…,n.

(12) Step 6. Calculate closeness between dangerous goods transport enterprise and its ideal points. The closeness between dangerous goods transport enterprise and ideal points is described as follows: Tj=dj−dj−+dj+, j=1,2,…,n. (13) Step 7. Rank the closeness order of all enterprises according to the value of T j. The bigger the value of T j, the safer

the enterprise j and less safe in opposite [11]. 3. The Safety Assessment Optimization Model of Dangerous Goods Transport Enterprise Based on the Relative Entropy Aggregation in Group Decision Making Through the above-mentioned model of safety assessment of multiobjective dangerous goods transport enterprise based on entropy [12, 13], each expert had calculated the value of T j for all enterprises in A. Suppose D = d k, k = 1,2,…, q is a group decision set, wherein d k stands for expert k. Let L = l k, k = 1,2,…, q be the weight vector of D; then use it to reflect the authority that experts have in group decision set, wherein l k ∈ [0,1], and ∑k=1 q l k = 1; the bigger the value of l k, the more authoritative the expert k. The method to calculate weight given by experts [14] is shown as follows. (1) Generate a set of preferences vector for enterprises T = T j, j = 1,2,…, n, where T j

= T kj, k = 1,2,…, q, T j stands for preference vector of the q experts preferring enterprise j, while T kj stands for preference of the expert k preferring enterprise j, and T kj can be calculated as we described above. (2) Make a cluster analysis [15] on data T 1j, T 2j,…, T qj in T j(j = 1,2,…, n). Taking T j, for example, suppose data T 1j, T 2j,…, T qj are finally clustered into x j sorts Anacetrapib (x j ≤ q); y j is the total number in the same sort. Namely, the number of sort 1 is y 1j and y i j for sort i. Let λ ij be the weight coefficient of expert in sort i; then there will be an existing constant d j which can make formula (14) valid: yij=dj·λij. (14) According to the definition of weight coefficient ∑i=1xjλij·yij=1. (15) From formulas (14) and (15) we can know λij=yij∑i=1xyij2. (16) (3) Calculate weight coefficient λ kj(k = 1,2,…, q, j = 1,2,…, n) of expert k on safety assessment of dangerous goods transport enterprises j using the above-mentioned method. Let λ k = ∑j=1 n λ kj(k = 1,2,…, q) be the sum of expert k’s authority on safety assessment of total n dangerous goods transport enterprises.