“…In the formula, is a constant, indicating the degree of ambiguity of certain comments, which can be determined based on historical data, or can be directly given by experts according to experience, while the value of cannot be too large, so as to avoid the error of being too large and the result being inaccurate. Based on relevant literature on risk assessment by the cloud model [20,21,28] and according to the effectiveness evaluation criteria for the physical protection system of a high security prison, this paper has set the ranks and corresponding scores of the comments as follows: low risk [0, 4], relatively low risk [4,6], medium risk [6,8], relatively high risk [8,9], and high risk [9,10], with the value of He being 0.03. According to this definition, this paper can obtain a table of digital characteristics for standard cloud models of risk (Table 2).…”