Abstract: The present disclosure provides a recycled powder concrete material for 3D printing construction and a preparation method therefor. The concrete material includes the following components by weight parts: cement: 1.0 part; recycled powder: 0.1-2.0 parts; recycled fine aggregate: 1.0-12.0 parts; nano titanium dioxide: 0.001-0.18 parts; high elastic modulus polyethylene fiber: 0.005-0.15 parts; redispersible latex powder: 0.002-0.1 parts; cellulose: 0.001-0.045 parts; activator: 0.01-0.30 parts; polycarboxylic acid water reducing agent: 0.005-0.2 parts; and water: 0.2-2.0 parts. According to the recycled powder concrete material for 3D printing construction, construction waste recycling powder technology is combined with 3D printing construction technology. The safety, applicability and durability of 3D printing recycled powder concrete material are further improved through the optimization of the recycled powder concrete formula.

Abstract: The present invention relates to the technical field of computer software analysis and discloses an RFC-directed differential testing method of certificate validations in a SSL/TLS implementations which includes: extracting rules from RFC and updating the rules, classifying the rules, further classifying consumer rules and shared rules into breakable rules and unbreakable rules, expressing the rules as variables, and generating a symbolic program; generating low-level test cases by applying the dynamic symbolic execution technique to the symbolic program; assembling high-level test cases i.e. digital certificates according to the low-level test cases; and employing the assembled digital certificates to the differential testing of the certificate validation in SSL/TLS implementations.

Abstract: A method for model checking path reduction based on interpolation comprises: reading a C program, performing grammatical and semantic analysis on the C program, and extracting CFG from an abstract syntax tree; adding safety (S) interpolation and error (E) interpolation to the CFG and extending the CFG; in a process of generating ARG according to the CFG, determining, in each state, whether the safety interpolation and the error interpolation are implied by current path formula. The method improves the verification efficiency by computing the S interpolation and the E interpolation, which makes the algorithm of the model checking a better use in large-scale programs. The S interpolation can be used to avoid the unnecessary traversal, greatly reducing the number of ARG state. The E interpolation can be used to quickly determine whether there is a true counterexample in the program, accelerating the program's verification and improving the efficiency.

Abstract: The present invention relates to the technical field of computer software analysis and discloses an RFC-directed differential testing method of certificate validations in a SSL/TLS implementations which includes: extracting rules from RFC and updating the rules, classifying the rules, further classifying consumer rules and shared rules into breakable rules and unbreakable rules, expressing the rules as variables, and generating a symbolic program; generating low-level test cases by applying the dynamic symbolic execution technique to the symbolic program; assembling high-level test cases i.e. digital certificates according to the low-level test cases; and employing the assembled digital certificates to the differential testing of the certificate validation in SSL/TLS implementations.

Abstract: A method for model checking path reduction based on interpolation comprises: reading a C program, performing grammatical and semantic analysis on the C program, and extracting CFG from an abstract syntax tree; adding safety (S) interpolation and error (E) interpolation to the CFG and extending the CFG; in a process of generating ARG according to the CFG, determining, in each state, whether the safety interpolation and the error interpolation are implied by current path formula. The method improves the verification efficiency by computing the S interpolation and the E interpolation, which makes the algorithm of the model checking a better use in large-scale programs. The S interpolation can be used to avoid the unnecessary traversal, greatly reducing the number of ARG state. The E interpolation can be used to quickly determine whether there is a true counterexample in the program, accelerating the program's verification and improving the efficiency.